Biomedical subjects

M Sawada

Publications and source records attributed to M Sawada.

At least 73 records · Page 4Linked to original sources

PubMed2000

Inhibition of the glutamate-induced K(+) current in identified Onchidium neurons by nitric oxide donors.

Nitric oxide (NO) acts as a neurotransmitter and neuromodulator in the nervous system of many vertebrates and invertebrates. The effects of extracellularly applied sodium nitroprusside (SNP) and diethylamine NO (C(2)H(5))(2)N[N(O)NO]-Na(+) (DEA/NO), NO donors, on a glutamate (Glu)-induced K(+) current in identified Onchidium neurons were investigated using voltage clamp and pressure ejection techniques. Bath-applied SNP (10 microM) and DEA/NO (5-10 microM) reduced the Glu-induced K(+) current without affecting the resting membrane conductance and holding current. The Glu-induced K(+) current also was inhibited by the focal application of SNP to the neuron somata. The suppressing effects of NO donors were concentration-dependent and completely reversible. Pretreatment with hemoglobin (50 microM), a nitric oxide scavenger, and 1H-[1,2, 4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 1 microM), a specific inhibitor of NO-stimulated guanylate cyclase, decreased the SNP-induced inhibition of the Glu-induced current. Bath-applied 50 microM 3-isobutyl-1-methylxanthine (IBMX), a nonspecific phosphodiesterase inhibitor, or intracellular injection of 1 mM guanosine 3',5'-cyclic monophosphate (cGMP) inhibited the Glu-induced current, mimicking the effect of NO donors. These results demonstrate that SNP and DEA/NO inhibit the Glu-induced K(+) current and that the mechanism of NO inhibition of the Glu-induced current involves cGMP-dependent protein kinase.

1-Methyl-3-isobutylxanthine↗

PubMed2000

Diminished prohormone convertase 3 expression (PC1/PC3) inhibits progastrin post-translational processing.

Gastrin is initially synthesized as a large precursor that requires endoproteolytic cleavage by a prohormone convertase (PC) for bioactivation. Gastric antral G-cells process progastrin at Arg(94)Arg(95) and Lys(74)Lys(75) residues generating gastrin heptadecapeptide (G17-NH(2)). Conversely, duodenal G-cells process progastrin to gastrin tetratriacontapeptide (G34-NH(2)) with little processing at Lys(74)Lys(75). Both tissues express PC1/PC3 and PC2. Previously, we demonstrated that heterologous expression of progastrin in an endocrine cell line that expresses PC1/PC3 and little PC2 (AtT-20) resulted in the formation of G34-NH(2). To confirm that PC1/PC3 was responsible for progastrin processing in AtT-20 cells and capable of processing progastrin in vivo we coexpressed either human wild-type (Lys(74)Lys(75)) or mutant (Arg(74)Arg(75), Lys(74)Arg(75), and Arg(74)Lys(75)) progastrins in AtT-20 cells with two different antisense PC1/PC3 constructs. Coexpression of either antisense construct resulted in a consistent decrease in G34-NH(2) formation. Gastrin mRNA expression and progastrin synthesis were equivalent in each cell line. Although mutation of the Lys(74)Lys(75) site within G34-NH(2) to Lys(74)Arg(75) resulted in the production of primarily G17-NH(2) rather than G34-NH(2), inhibition of PC1/PC3 did not significantly inhibit processing at the Lys(74)Arg(75) site. We conclude that PC1/PC3 is a progastrin processing enzyme, suggesting a role for PC1/PC3 progastrin processing in G-cells.

Aspartic Acid Endopeptidases↗

PubMed2000

Identification of a novel alternative splicing of human FGF receptor 4: soluble-form splice variant expressed in human gastrointestinal epithelial cells.

Among four closely related members of the FGF receptor family, FGFR 1, 2, and 3 have alternative splicing forms encoded by different exons for the C-terminal half of the third Ig-like domain, but FGFR 4 has no such alternative exon. Furthermore, FGFR 1, 2, and 3 have another splice variant of nontransmembrane type; however, such a variant has not been reported for FGFR 4. While searching for a novel receptor-type tyrosine kinase by RT-PCR, we identified a non-transmembrane-type receptor of FGFR 4 in human intestinal epithelial cell lines (Intestine 407 and Caco-2). Sequence analysis of this receptor revealed that exon 9 coding the single transmembrane domain was displaced by intron 9. Consequently, this variant form was 120 bp shorter than the normal form and had no transmembrane portion. Moreover, the signal sequence in exon 2 was maintained, suggesting that this splice variant is a soluble receptor. This soluble receptor was detected in human gastrointestinal epithelial cells and pancreas, and also in gastric, colon, and pancreatic cancer cell lines. Single cell RT-PCR showed that this soluble receptor was expressed simultaneously with the transmembrane-type receptor in the same cell. Western blot analysis revealed that this receptor was secreted from the transfected COS7 cells. Thus, a soluble-form splice variant of FGFR 4 was identified in human gastrointestinal epithelial cells and cancer cells. This is the first report of alternative splicing of FGFR 4.

Alternative Splicing↗

PubMed2000

Serum-soluble fas level determines clinical symptoms and outcome of patients with aggressive non-Hodgkin's lymphoma.

Soluble Fas (sFas) blocks apoptosis induced by Fas ligand in vitro. The serum concentration of sFas is elevated in lympho-proliferative diseases. We hypothesized that higher levels of sFas worsen the clinical symptoms and outcome of patients with aggressive non-Hodgkin's lymphoma (NHL). We prospectively measured the serum concentrations of sFas in 67 consecutive patients with aggressive NHL (59 with diffuse large cell lymphoma and 8 with diffuse small cleaved cell lymphoma). sFas was significantly elevated in patients with aggressive NHL compared to healthy controls (N = 36, P< 0.005), while sFas in patients with B symptoms (4.20 +/- 2.12 microg/l) was significantly higher than in those without B symptoms (2.66 +/- 1.08 microg/l, P < 0.005). No significant difference was observed between B-cell lymphoma and T-cell lymphoma or between patients with clinical stage I or II and those with clinical stage III or IV. Significant correlations were found between sFas concentration and both soluble interleukin-2 receptor (R = 0.400, P < 0.001) and C-reactive protein (R = 0.340, P < 0.01) levels in patients with aggressive NHL. No correlation was observed between sFas and either white blood cell count or lactate dehydrogenase. Generalized Wilcoxon analysis revealed that NHL patients with sFas less than 4 microg/l had better overall survival than those with sFas above 4 microg/l (P < 0.001). The serum concentration of sFas might be associated with clinical symptoms and the prognosis of patients with aggressive NHL.

Adolescent↗

PubMed2000

Temporal fluctuations of voltage-gated proton currents in rat spinal microglia via pH-dependent and -independent mechanisms.

Voltage-gated proton (H(+)) channels are unique mechanisms to extrude a massive amount of H(+), and are proposed to regulate intracellular pH of microglia during respiratory bursts. Temporal variations of the H(+) current were studied in rat spinal microglia cultivated on the glial cell layer using the voltage-ramp protocol. Repetitive applications of the large and long-lasting depolarization decreased the amplitudes of the H(+) current transiently and reversibly. This decrease was accompanied by a shift of the reversal potential to a more positive direction, indicating that a drop in the transmembrane pH gradient (delta pH) by the H(+) efflux through the channel reduced the current. The decline of the H(+) current during depolarizations was also observed in a rat microglial cell line (GMI-R1). An increase in the extracellular buffer suppressed the reduction of the current, suggesting that H(+) secreted into the extracellular space contributed to the drop in delta pH. On the other hand, the amplitudes of the H(+) current often fluctuated greatly at intervals of 5-20 min without changes in delta pH. These results suggest that the H(+) current of microglia is tuned via both delta pH-dependent and -independent mechanisms, which may regulate both microglial behavior and the pH environments of the surrounding neural tissue.

Animals↗

PubMed2000

Ribose 1,5-bisphosphate is a putative regulator of fructose 6-phosphate/fructose 1,6-bisphosphate cycle in liver.

6-Phosphofructo-1-kinase and fructose-1,6-bisphosphatase are rate-limiting enzymes for glycolysis and gluconeogenesis respectively, in the fructose 6-phosphate/fructose 1,6-bisphosphate cycle in the liver. The effect of ribose 1,5-bisphosphate on the enzymes was investigated. Ribose 1,5-bisphosphate synergistically relieved the ATP inhibition and increased the affinity of liver 6-phosphofructo-1-kinase for fructose 6-phosphate in the presence of AMP. Ribose 1,5-bisphosphate synergistically inhibited fructose-1,6-bisphosphatase in the presence of AMP. The activating effect on 6-phosphofructo-1-kinase and the inhibitory effect on fructose-1,6-bisphosphatase suggest ribose 1,5-bisphosphate is a potent regulator of the fructose 6-phosphate/fructose 1,6-bisphosphate cycle in the liver.

Animals↗

PubMed2000

Impaired cytokine production by peripheral blood mononuclear cells and monocytes/macrophages in Parkinson's disease.

OBJECTIVE: Although the pathogenesis of Parkinson's disease (PD) is still unknown, several reports suggest the presence of immunological abnormalities in the patients with PD such as impaired T cell responses or cytokine production by the peripheral immune system. MATERIAL AND METHOD: In this study, we examined cytokine production by peripheral blood mononuclear cells (PBMC) and monocyte/macrophages (PBM) in the patients with idiopathic PD, using age-related healthy donors as a normal control and cerebrovascular diseases (CVD) as a disease control. RESULTS: Production of TNF-alpha, IL-1alpha, IL-1beta and IL-6 by PBMC and TNF-alpha by PBM were significantly lower in the patients with PD as compared to the control groups. IFN-gamma production by LPS-stimulated PBMC in the patients with PD was also significantly lower than that in control groups. Cytokine production by PBMC from the patients with CVD who had a similar disability as the patient group was not significantly different from those in normal controls. Thus, impaired production of inflammatory cytokines may not be due to the mental and physical stress caused by their disability. CONCLUSION: In the patients with PD, a significant negative correlation was noted in 1alpha-1beta, IL-1beta and IL-6 levels produced by LPS-stimulated PBMC and Hoehn Yahr disability score of the patients, suggesting that the impaired cytokine production may progress with disease progression. These abnormalities in cytokine production may not be primary but may affect the prognosis of PD.

Aged↗

PubMed2000

Paraquat-induced membrane dysfunction in pulmonary microvascular endothelial cells.

Membrane dysfunction monitored by lactate dehydrogenase release from cultured pulmonary microvascular endothelial cells of pigs, which were exposed to paraquat at different concentrations (0.1-2 mM), was examined. Paraquat caused a time-dependent increase in lactate dehydrogenase release. Lactate dehydrogenase releases after 72 hr, 32, 58, and 84% by 0.1, 0.5, and 2 mM paraquat, respectively, were well correlated with cell viability measured by cell adherence. In contrast, reductions of two tetrazolium compounds were depleted profoundly by 72 hr after exposure to 0.5 mM paraquat, suggesting depletion of intracellular reductive substances. Extracellular hydrogen peroxide began to significantly increase 56 hr or 32 hr after exposure to 0.5 mM or 1.5 mM paraquat, respectively, preceding the initial increase of lactate dehydrogenase release (64 hr by 0.5 mM or 48 hr by 1.5 mM). Lactate dehydrogenase release 72 hr after exposure to 0.5 mM paraquat was prevented strongly by catalase (1000 units/ml), but weakly by superoxide dismutase (1000 units/ml). These enzymes failed to restore the reduced acid phosphatase activity. Also, 0.1 mM desferal or alpha,alpha'-dipyridyl protected lactate dehydrogenase release. Similarly, 1 mM thiourea or dimethylthiourea, and 0.5 mM alpha-tocopherol or trolox, were effective, but diethylenetriaminepentaacetic acid (0.1 mM) and probucol (5 or 10 microM) were ineffective. Exposure of 0.5 or 1.5 mM paraquat suppressed levels of lipid peroxidation. These results indicate that membrane dysfunction by paraquat is ascribed to an iron-catalyzed reaction of extracellularly increased hydrogen peroxide. A deleterious species for the membrane dysfunction is discussed.

Acid Phosphatase↗

PubMed2000

Ordering of ceramide formation, caspase activation, and Bax/Bcl-2 expression during etoposide-induced apoptosis in C6 glioma cells.

Etoposide (VP-16) a topoisomerase II inhibitor induces apoptosis of tumor cells. The present study was designed to elucidate the mechanisms of etoposide-induced apoptosis in C6 glioma cells. Etoposide induced increased formation of ceramide from sphingomyelin and release of mitochondrial cytochrome c followed by activation of caspase-9 and caspase-3, but not caspase-1. In addition, exposure of cells to etoposide resulted in decreased expression of Bcl-2 with reciprocal increase in Bax protein. z-VAD.FMK, a broad spectrum caspase inhibitor, failed to suppress the etoposide-induced ceramide formation and change of the Bax/Bcl-2 ratio, although it did inhibit etoposide-induced death of C6 cells. Reduced glutathione or N-acetylcysteine, which could reduce ceramide formation by inhibiting sphingomyelinase activity, prevented C6 cells from etoposide-induced apoptosis through blockage of caspase-3 activation and change of the Bax/Bcl-2 ratio. In contrast, the increase in ceramide level by an inhibitor of ceramide glucosyltransferase-1, D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol caused elevation of the Bax/Bcl-2 ratio and potentiation of caspase-3 activation, thereby resulting in enhancement of etoposide-induced apoptosis. Furthermore, cell-permeable exogenous ceramides (C2- and C6-ceramide) induced downregulation of Bcl-2, leading to an increase in the Bax/Bcl-2 ratio and subsequent activation of caspases-9 and -3. Taken together, these results suggest that ceramide may function as a mediator of etoposide-induced apoptosis of C6 glioma cells, which induces increase in the Bax/Bcl-2 ratio followed by release of cytochrome c leading to caspases-9 and -3 activation.

Animals↗

PubMed2000

Activation of caspase-9 and -3 during H2O2-induced apoptosis of PC12 cells independent of ceramide formation.

The treatment of PC12 cells with H2O2 (100-500 microM) resulted in typical apoptotic changes including fragmentation and condensation of nuclei, and DNA fragmentation observed as DNA ladder. H2O2-induced apoptosis was associated with activation of caspase-3 as assessed by cleavage of specific fluorogenic substrate peptide and processing of procaspase-3 and poly(ADP-ribose) polymerase. However, formation of ceramide, which often locates upstream of caspase-3, was not observed. The inhibitory peptide relatively specific for caspase-3, z-DEVD-FMK and non-selective caspase inhibitor z-VAD-FMK inhibited activation of caspase-3 and apoptotic cell death. However, the relatively specific inhibitors, Ac-YVKD for caspase-1 and Ac-IETD for caspase-8/6, did not affect the occurrence of apoptotic cell death. As an upstream activation of caspase-3, induction of cytochrome c release followed by processing of procaspase-9 was observed by Western blotting, although the formation of intracellular ceramide was not observed. On the other hand, in PC12 cells overexpressing Bcl-2, the number of apoptotic cells was markedly decreased and activation of both caspases-9 and -3 was prevented. These results suggest that cytochrome c and caspase-9 initiate the activation of executor caspase-3 in H2O2-treated PC12 cells, and that Bcl-2 inhibits H2O2-induced release of cytochrome c from mitochondria and then proteolytic processing of procaspase-9.

Animals↗

PubMed2000

Elevated transferrin concentration in cerebral spinal fluid after subarachnoid hemorrhage.

Calcium-elevating protein cross-reacted with anti-human transferrin (TF) was purified in cerebrospinal fluid (CSF) after subarachnoid hemorrhage (SAH). The concentration of TF in CSF after SAH was measured, and the effects of TF on cultured smooth muscle cells (SMCs) were evaluated in order to understand the relationship between TF and cerebral vasospasm. Cisternal CSF samples were collected from 12 patients (seven men and 13 women) with SAH due to the rupture of a cerebral aneurysm, and eight control subjects. The patients were divided into two groups: (1) those presenting no clinical and radiological evidence of vasospasm (the non-vasospasm group; three men and 10 women, mean age 54.7 years), and (2) those presenting evidence of vasospasm (the vasospasm group; four men and three women, mean age 58.3 years). The concentration of TF in CSF was measured using Speriol micro-transferrin measure assay method. Nitrite accumulation in the culture media of SMCs incubated with TF was determined by diazotization method. The mRNA levels of inducible isoform of NOS (iNOS) in SMC incubated with TF were measured by the reverse transcription-coupled polymerase chain reaction method. Levels of TF were markedly different in the SAH and the control subjects. In the control group, all subjects had no detectable quantity of TF. In contrast, all patients after SAH had quantifiable TF in their CSF. Moreover, there was a significant difference between the vasospasm group and the non-vasospasm group in TF levels (p < 0.05). In the vasospasm group, the average value was 10.43 +/- 2.8 mg dl-1. In the non-vasospasm group, the average was 3.69 +/- 0.31 mg dl-1. The nitrite content in the culture medium incubated with TF was three times the content of control. TF also induced iNOS mRNA in SMC. This study demonstrated that an elevation of TF concentration in CSF after SAH was detected and iNOS mRNA in SMCs was also induced by TF. This may be involved in some roles of the development of the pathological series of events after SAH, including vasospasm.

Adult↗

PubMed2000

Estrogen receptor antagonist ICI182,780 exacerbates ischemic injury in female mouse.

Recent findings in animals emphasize that experimental ischemic brain damage can be strikingly reduced by estrogen: however, the neuroprotective mechanisms are not well understood. It was hypothesized that estrogen signaling via cognate estrogen receptors (ERs) within the vasculature is an important aspect of cerebral ischemic protection in the female brain, in part by amplifying intraischemic cerebral blood flow (CBF). In the present study, the hypothesis that chronic treatment with the pure ER antagonist ICI182,780 (ICI) would increase ischemic brain damage by a blood flow-mediated mechanism was investigated. Adult C57B1/6J mice were pretreated with either subcutaneous ICI (100 microg/day) or oil/ethanol vehicle for 1 week before 2 hours of middle cerebral artery occlusion (MCAO) and 22 hours of reperfusion. End-ischemic regional CBF was evaluated in additional cohorts using [14C]iodoantipyrine autoradiography. Infarction volume as measured by cresyl violet histology was greater in the striatum of ICI-treated females (70 +/- 3% of contralateral striatum vs. 40 +/- 12% in vehicle-treated females). Cortical injury was not enhanced relative to control animals (39 +/- 6% of contralateral cortex in ICI group vs. 27 +/- 8% in vehicle-treated group). Physiologic variables and ischemic reduction of the ipsilateral cortical laser-Doppler flow signal were similar between groups. Further, ICI treatment did not alter end-ischemic cortical or striatal CBF. The deleterious effect of ICI was limited to females, as there were no differences in stroke damage or CBF between male treatment groups. These data suggest that estrogen inhibits ischemic brain injury in striatum of the female by receptor-mediated mechanisms that are not linked to preservation of intraischemic CBF.

Animals↗

PubMed2000

Ibudilast modulates platelet-endothelium interaction mainly through cyclic GMP-dependent mechanism.

3-Isobutyryl-2-isopropylpyrazolo[1,5-a]pyridine (ibudilast) has been widely used in Japanese clinics for its antiasthmatic and antithrombotic effects. We investigated the mechanisms involved in the antiplatelet effects of the agent, specifically focusing on platelet-endothelium interaction. Ibudilast inhibits both phosphodiesterase (PDE) 3 and 5, the two major PDE isoforms of human platelets, with an IC50 of 31 and 2.2 microM, respectively. Cyclic guanosine monophosphate (GMP) accumulation in washed human platelets exposed to ibudilast alone increased significantly only at high concentrations of the agent (100 microM), whereas > or = 1 microM ibudilast enhanced cyclic GMP levels in the platelets cocultured with bovine aorta endothelial cells (ECs). In contrast, ibudilast enhanced cyclic AMP accumulation only at 100 microM, either with or without ECs. The synergistic effect of ibudilast and EC on cyclic nucleotide accumulation also was demonstrated by the inhibitory capability of the drug and the cells on platelet aggregation. The synergism between ibudilast and aspirin-pretreated ECs was more pronounced than that between ibudilast and N(omega)-nitro-L-arginine (L-NNA)-pretreated ECs. Ibudilast affected neither ATP diphosphohydrolase activity nor NO release from EC up to a concentration of 10 microM. We conclude that ibudilast exhibits antiplatelet properties mainly by inhibiting PDE5 to potentiate antiplatelet function of endothelium-derived NO.

Animals↗

PubMed2000

Crystallization and preliminary X-ray analysis of endopolygalacturonase SE1 from Trichosporon penicillatum.

Endopolygalacturonase SE1 from Trichosporon penicillatum has been crystallized by the hanging-drop method of vapour diffusion using ammonium sulfate as a precipitant. The crystals belong to the hexagonal space group P6(1) or P6(5), with unit-cell parameters a = b = 135.0, c = 70.7 A, gamma = 120 degrees. The calculated V(M) based on one molecule per asymmetric unit is 3.09 A(3) Da(-1). A native data set from a crystal has been collected to 2.0 A resolution on a Cu Kalpha rotating-anode X-ray source.

Crystallography, X-Ray↗

PubMed2000

Induction of follicular gastritis following postthymectomy autoimmune gastritis in Helicobacter pylori-infected BALB/c mice.

Helicobacter pylori is the major causative agent of chronic antral gastritis and is thought to be involved in the pathogenesis of mucosa-associated lymphoid tissue lymphoma (MALToma) developing in the human stomach. The aim of this study was to clarify whether corporal autoimmune gastritis (AIG), which is known to decrease acidity due to destruction of parietal cells, predisposes mice to H. pylori infection, thereby leading to MALToma-like pathology. BALB/c mice in which AIG had been induced by thymectomy 3 days after birth (AIG mice) were used. The AIG mice were orally administered mouse-adapted H. pylori at the age of 6 weeks and were examined histologically and serologically after 2 to 12 months. The results were compared with those obtained from uninfected AIG mice and infected normal mice. Germinal centers were induced in the corpus in 57% of the H. pylori-infected AIG mice, which elicited anti-H. pylori antibody responses in association with upregulation of interleukin-4 (IL-4) mRNA. In these mice, parietal cells remained in the corpus mucosa. These findings were in contrast to those with the uninfected AIG mice: fundic gland atrophy due to disappearance of parietal cells associated with upregulation of gamma interferon, but not IL-4, mRNA and no germinal center formation in the corpus. These observations suggest that AIG alters the infectivity of H. pylori, leading to MALToma-like follicular gastritis, at an early stage after H. pylori infection.

Animals↗

PubMed2000

Graft failure of autologous peripheral blood stem cell transplantation due to acute metabolic acidosis associated with total parenteral nutrition in a patient with relapsed breast cancer.

A 32-year-old female had been diagnosed as having relapsed breast cancer and liver metastasis. She underwent high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT) with 5.8 x 10(6)/kg CD34+ cells. She was supported by total parenteral nutrition (TPN) without vitamins throughout these therapies. Hematopoietic recovery was not observed by day 28 after PBSCT, necessitating a second PBSCT on day 29 using the back-up material of 4.4 x 10(6)/kg CD34+ cells. On the next day, she suddenly developed severe metabolic acidosis, heart failure and deep coma. After immediate infusion of thiamine, heart failure and coma rapidly improved. The neutrophil count reached 0.5 x 10(9)/l on day 9 and the platelet count 50 x 10(9)/l on day 15 after the second PBSCT. This is a rare graft failure due to acute metabolic acidosis or thiamine deficiency associated with TPN.

Acidosis↗

PubMed2000

Neospora caninum infected the alimentary tract of nude mice and was transmitted to other mice by intraperitoneal inoculation with the intestinal contents.

Neospora caninum (BT-2 strain) that originated from the brain of a Holstein calf was serially passaged through 10 generations of BALB/c nude mice by intraperitoneal inoculation. Histological examination of the mice revealed that numerous clusters of tachyzoites appeared in the pancreas, stomach and small intestine as well as in the central nervous system (CNS) and skeletal muscles. Intestinal contents of the infected mice were inoculated intraperitoneally into uninfected nude mice and 3 of the 17 inoculated mice showed clinical signs at post inoculation days 3 to 10. The present experiments demonstrated a proliferation of N. caninum tachyzoites in the mucosa of the alimentary tract and pancreas of the nude mice and the intestinal contents of the mice were infective to other nude mice.

Animals↗

PubMed2000

Inhalation provocation tests in chronic bird fancier's lung.

BACKGROUND: Patients with chronic bird fancier's lung (BFL) can be classified into two types. One group of patients develops chronic disease with fluctuating acute episodes, including low-grade fever, mild exertional dyspnea, and cough (fluctuating chronic BFL; formerly termed recurrent and relapsing chronic BFL). The other group of patients shows no history of acute episodes (insidious chronic BFL). The diagnosis of chronic BFL is difficult, since the onset of chronic BFL may be insidious, with few if any symptoms during the early stages of the disease process. STUDY OBJECTIVE: To attempt to diagnose the conditions of these patients more precisely, inhalation provocation tests were conducted using avian dropping extracts. DESIGN: Retrospective chart review. SETTING: The Tokyo Medical and Dental University Hospital in Japan. PATIENTS: Eleven patients with chronic BFL (6 with fluctuating chronic BFL and 5 with insidious chronic BFL) and 6 control subjects (4 asymptomatic bird owners and 2 idiopathic pulmonary fibrosis patients) were evaluated. MEASUREMENTS AND RESULTS: Inhalation provocation tests using avian dropping extracts were conducted. All BFL patients were evaluated as positive or probable by inhalation challenge, whereas control subjects were evaluated as negative. A peripheral leukocytosis, an increase of alveolar-arterial oxygen pressure difference, an increase of body temperature, and the development of respiratory symptoms including cough and dyspnea were more frequently observed in chronic BFL patients than in control subjects. All the BFL patients had an increase in neutrophils in BAL fluids following inhalation challenge. CONCLUSIONS: We validated the utility of inhalation challenge for the diagnosis of chronic BFL, including fluctuating and insidious BFL. We also demonstrated that neutrophilia in BAL fluids following inhalation challenge could be added to the diagnostic criteria for chronic BFL.

Acute Disease↗