[Clinical usefulness of histamine release test in determining allergens in food hypersensitivity]

We examined the clinical usefulness of three diagnostic tests including the histamine release test, RAST and prick test in determining which of a total of 349 allergens were responsible for individual cases of food hypersensitivity. The subjects were 42 children (mean 3.3 years old). When compared with the results of the offending allergen confirmed by elimination and provocation test, each diagnostic test showed a fairly good correlation in percentage agreement and negative agreement, but there was poor correlation in positive agreement (histamine release test 58.1%, RAST 62.8%, prick test 48.8%). False positive results were more frequently observed in RAST (12.6%) as compared with the histamine release test (4.0%) and prick test (2.3%). McNemar's analysis demonstrated that the histamine release test, but not RAST or the prick test, was matched the diagnosis by elimination and provocation test (alpha = 0.30). These results suggest that the histamine release test is more clinically useful than RAST or the prick test in the diagnosis of food hypersensitivity.

[Changes in antigen-specific IgG, IgG4, and IgE antibodies in patients receiving immunotherapy with house-dust extract]

We measured allergen-specific IgG, IgG4, IgE antibodies and total IgE in sera from 64 patients who were receiving conventional immunotherapy (IT) with house dust (HD) extract. The sera were taken before and after IT. To measure allergen-specific antibodies, we used crude DF antigen, Der f I and Der f II for IgG and IgG4 antibodies, and crude DF antigen for IgE antibodies. The patients were divided into 3 groups: very short term group (IT period < 2 years, n = 9); short term group (2 < = IT period < 7 years, n = 25); long term group (7 years < = IT period, n = 30). The specific IgG antibodies for DF crude antigen did not change in any group. The specific IgG antibodies for Der f I and Der f II increased in the short term group and in the long term group. The specific IgG4 antibodies for all three antigens increased remarkably in the short term group and in the long term group. In the very short term group, however, the specific IgG4 antibodies did not increase for any antigen. Total IgE and the specific IgG antibodies did not change through IT. The specific IgG4 antibodies increased significantly through IT, but the time course of the increment of the IgG4 antibodies was not parallel with the clinical course of IT.

[Immunological and physicochemical properties of Cry j II, the second major allergen of Japanese cedar pollen (Cryptomeria japonica)]

Cry j II, the second major allergen of Japanese cedar (sugi, Cryptomeria japonica) pollen was examined for the allergenicity by intradermal test and RAST. Nineteen of the 25 allergic patients examined, showed positive reaction to the Cry j II. Contents of Cry j II in the extracts of the pollen collected in various regions from 1977 to 1991 showed yearly variation ranging from 2.9 to 14 mg/100 g pollen, whereas the amount of Cry j I in the extract was comparatively stable at about 35 mg/100 g pollen. Physicochemical treatments of Cry j I and Cry j II suggested that specific human IgE antibodies and some mAbs bind to conformational epitopes which are denatured and destroyed by certain treatments.

[A study of sensitization and symptoms in adult asthmatics who keep cat and dog]

We studied hypersensitivity to cats and dogs in three hundred adult asthmatics who kept them. Some findings were noted as follows. 1) The mean duration for which cats were kept was 6.2 +/- 10.1 (1 S.D.) years and that for dogs was 4.2 +/- 9.6 (1 S.D.) years. 2) The positive rate in intradermal tests to dog dander was 7% and to cat hair-epithelium 32%. The positive RAST (score > or = 2) rate to cat epithelium was 36.1%, to dog dander 31.6% and to dog epithelium 7.3% respectively. 3) Eleven to 18% of the dog keepers and 23 to 36% of the cat keepers whose RAST score were positive were aware of the relationship between pets and asthma, specifically concerning eye and nose symptoms. 4) Thirty percent of the cat and dog keepers had become sensitized to them after keeping them for under one year. The positive RAST rate was unchanged in those who kept Japanese native dogs but increased in those who kept foreign breeds after 3 to 6 years. The rate of sensitization rate to cats tended to increase along with the period for which they were kept. 5) Dog dander RAST scores among the foreign breed keepers were significantly higher than those among the native dog keepers. If the dog breed was the same, the RAST score was not higher if the dog was kept indoors than if it was kept outdoors. We concluded that a possible reason why the RAST scores were higher among those who kept foreign breeds was that foreign breeds have stronger allergenicity.

Chemical synthesis and properties of an oligodeoxyribonucleotide containing a 2-deoxyribosylformamide residue

To elucidate the conformational properties of DNA with a 2-deoxyribosylformamide residue (dF), an oligodeoxyribonucleotide containing this abasic residue in a specific position of the nucleotide sequence was synthesized by the standard solid-phase phosphotriester method. Deprotection of the synthesized oligonucleotide was performed under routine alkaline and acidic conditions. The presence of a dF residue in the oligomer was confirmed by ion-spray mass spectrometry. A dF residue was found to affect considerably the stability of the DNA duplex, as determined from the melting behavior of the dF-containing duplex.

Allergens from Dermatophagoides mites with chymotryptic activity

A new set of allergens from Dermatophagoides pteronyssinus and D. farinae (provisionally named DP5 and DF5, respectively) was isolated from the whole culture of mites. The apparent molecular weights of both allergens were shown to be 25,000 on SDS-PAGE under a reducing condition and 27,000 on Sephadex G-75 gel filtration chromatography. Both DP5 and DF5, as well as Der f III, possessed proteolytic activity. The results of substrate specificity and susceptibility to various protease inhibitors of DP5 and DF5 strongly suggested that they belonged to the chymotrypsin-like serine protease family. In sera from 88 mite-allergic patients, specific IgE antibodies to DP5 and/or DF5 were detected in only 41% of the sera by radio-allergosorbent test, while 90% and 93% had specific IgE antibodies to Der p I and/or Der f I and Der p II and/or Der f II, respectively.

Efficient preparation of monospecific anti-canine C-reactive protein serum and purification of canine C-reactive protein by affinity chromatography

The canine C-reactive protein (CRP) fraction isolated from canine acute-phase serum on a phosphorylcholine-Sepharose 4B column was further subjected to Sephacryl S-300 gel filtration. A canine CRP fraction not containing IgM was then obtained. The antisera, obtained after several immunizations with this canine CRP fraction, contained nonspecific antibodies that reacted with albumin, transferrin and IgG in addition to CRP. This antiserum could be easily changed to monospecific canine CRP serum, when it was subjected to absorption for only 15 min using glutaraldehyde-insolubilized normal canine serum protein containing 3.5 micrograms ml-1 of CRP. Pure canine CRP was isolated with a recovery rate of 95% from canine acute-phase serum by affinity chromatography using specific anti-canine CRP antibody.

[Advance in the method of eosinophil separation--separation of human eosinophils in density gradients and measurement of density distribution]

To separate human eosinophils from peripheral blood, we used six discontinuous density gradients of Percoll solution (1.070, 1.080, 1.085, 1.090, 1.095 and 1.100 g/ml). Eosinophils isolated from patients with bronchial asthma or hypereosinophilic syndrome (HES) were shifted to the lighter density as compared with that from healthy subjects. Light-shift of density of eosinophils (hypodense eosinophils) was mimicked by several agents including chemical mediators such as histamine or platelet-activating factor (PAF), cytokines such as interleukin (IL)-3, IL-5 or GM-CSF. It has been reported that hypodense eosinophils survive, and the ability to generate leukotriene C4, superoxide anion or to secrete tissue injurious protein such as ECP or MBP augments as compared with that of normal density (normodense eosinophils). This separation method of eosinophils using a Percoll solution may contribute to accurate understanding a role of eosinophils in the pathogenesis of bronchial asthma or HES.

[Eosinophilic cystitis]

Nine cases were diagnosed to be eosinophilic cystitis on the basis of histological criteria and clinical observations were made on these cases. In all cases, a past history of allergic or collagen diseases were revealed. Eosinophils in urine were present in 8 out of 9 cases and allergic tests were then performed. Histamine release from biopsied bladder tissue, incubated with anti-IgE, were first examined and a higher level than control was found. Next, intravesical provocation test (IgE RAST positive allergen was introduced into vesical cavity) revealed the appearance of bladder irritabilities within 30 minutes and release of urinary histamine within 3 hours. In 3 cases, provocation tests by eating food were performed and 2 out of 3 cases showed a positive reaction. These results show that allergy may be related to the development of eosinophilic cystitis in part.

Changes in serum C-reactive protein levels in dogs with various disorders and surgical traumas

The serum levels of C-reactive protein (CRP) produced as an inflammatory response in dogs with various disorders and surgical traumas were measured by enzyme-linked immunoabsorbent assay and slide reversed passive latex agglutination test (RPLA). The CRP levels were greatly increased 1-2 days after surgery in most of the dogs (n = 29) subjected to surgery. These levels had markedly decreased by the time the sutures were removed. In dogs with various disorders (n = 58), the serum CRP levels at first diagnosis were high in infectious diseases. In dogs from which paired serum samples were examined, the serum CRP usually showed a decrease with improvement in the condition (n = 11) or a terminal increase (n = 4) but, conversely, some showed an increase with improvement in the condition (n = 3).

Expression of muscarinic and nicotinic receptor mRNA in the salivary gland of rats: a study by in situ hybridization histochemistry

Expression of muscarinic receptor mRNA subtypes (m1-5) and nicotinic receptor subunits (alpha 2-4, and beta 2) was examined in the rat submandibular gland by in situ hybridization histochemistry, using oligonucleotide probes for the muscarinic receptor and RNA probes for the nicotinic receptors. m2, alpha 3, and beta 2 mRNA were strongly expressed in the submandibular ganglion, and m3, alpha 2, alpha 3, alpha 4, and beta 2 were expressed in the striated and interlobular duct cells. Both muscarinic and nicotinic receptors were coexpressed in the same ganglion neurons, while none of these mRNA were detected in the terminal secretory units.

[A successful VA bypass treatment in patient with severe pulmonary hypertension]

Report of a case of a patient with pulmonary hypertension associated with pericardial effusion who was treated by VA bypass during life-threatening right ventricular failure. A 63-year-old man was admitted to our hospital complaining of chest pain and dyspnea. Echocardiography revealed the patient had severe pulmonary hypertension and pericardial effusion. Though there were deep Q waves in ECG, his coronary angiography revealed normal coronary arteries. Pulmonary scintigraphy showed no evidence of pulmonary thromboembolism. As he developed hypotension and anuria, emergency pericardial drainage was carried out without any beneficial effect. Because no effective drugs were found to control his systemic hypotension and pulmonary hypertension, he was treated by VA bypass to save his life. Although his systemic pressure rose to normal level following institution of VA bypass, his pulmonary pressure remained high constantly, around 60-70mmHg. The VA bypass was discontinued on the 6th day because of bleeding tendency. 3 months after VA bypass, though he had not been given any drugs to control pulmonary hypertension, his pulmonary arterial pressure dropped down to within normal range. Though the exact mechanism or etiology of pulmonary hypertension remained unclear, this may be a rare case treated by VA bypass successfully for life-threatening right ventricular failure caused by pulmonary hypertension.

[Specific IgE antibody titers to hen's egg white lysozyme in allergic children to egg]

Hen's egg white lysozyme (HEL) is one of the minor allergen in hen's egg white. HEL is commonly used to treat disease of respiratory tract, because it have the effect to dissolve mucopolysaccharide and anti-inflammatory action. We examined specific IgE antibody titers (IgE-HEL) in patients with egg allergy and allergic patients to other antigen than egg. Results indicated that 16.37 +/- 29.56 (PRU/ml) (mean +/- SD) of IgE-HEL was found in 30 out of the 39 allergic patients to egg, and 23 (66.7%) out of the 39 patients studied showed RAST scores of more than 2. On the other hand, 1.08 +/- 0.92 (PRU/ml) of IgE-HEL in 12 out of the 44 allergic patients to other antigen than egg, and 5 (11.4%) out of the 44 patients studied showed RAST scores of more than 2. Moreover, we treated a patient who developed anaphylaxis after taking HEL. 1.0 (PRU/ml) of HEL-IgE was found in this patient. These results suggest that we should be careful in treating allergic patients with HEL.

Platelet-activating-factor-induced augmentation of production of eosinophil-lineage cells in hematopoietic precursor cells obtained from human umbilical cord blood

Platelet-activating factor (PAF)-induced augmentation of spontaneous differentiation into eosinophil-lineage cells from hematopoietic precursor cells was found among human umbilical cord blood mononuclear cells (CBMCs). This ability of PAF to augment eosinophil production was significantly (p < 0.01) inhibited by the addition of the anti-PAF agent WEB 2086. This enhancing effect of PAF was significantly (p < 0.01) diminished by the presence of antibodies to interleukin (IL)-1 alpha, -beta and IL-3, whereas antibodies to IL-5 or granulocyte-macrophage colony-stimulating factor (GM-CSF) did not diminish it. IL-1 beta, IL-3 or IL-5 gene expression was detected in cellular RNA isolated from both medium- and PAF-stimulated CBMCs using the reverse transcription polymerase chain reaction (RT-PCR) method; however, no expression of GM-CSF was detected. Moreover, 5 times as much IL-3 was detected in the PAF-stimulated CBMC culture supernatant than in that of cells treated with the medium. In the case of IL-1 beta, there was no difference between the 2 cell preparations. On the other hand, no IL-5 or GM-CSF was detected in the supernatant after stimulation with medium or PAF. Depletion of CD2+, CD16+ or CD19+ cells, but not CD14+ cells, from CBMCs resulted in a marked decrease in PAF-induced augmentation of eosinophil production. These results suggest that PAF induces the augmentation of IL-3 production in CBMCs which in turn enhances differentiation into eosinophil-lineage cells.

Effect of butyric acid on induction of differentiation into eosinophil-like cells in human eosinophilic leukemia cells, EoL-1 cell line: possible role of granulocyte-macrophage colony-stimulating factor as an autocrine differentiating factor

EoL-1 cells differentiated into mature eosinophil-like cells when incubated with butyric acid (BA). The differentiated cells possessed many granules that stained with Luxol fast blue and acquired the ability to produce leukotriene C4 and eosinophil cationic protein (ECP), and migrated toward some eosinophillotactic attractants, including PAF, IL-5, IL-3 and GM-CSF. Monoclonal antibody to GM-CSF and IL-5, especially GM-CSF, strongly decreased the ability of BA to induce differentiation, whereas antibody to IL-3 did not. Recombinant human (rh) IL-3, rhGM-CSF and recombinant mouse (rm) IL-5, by themselves, did not have the ability to induce differentiation. On the other hand, the presence of these cytokines significantly (p < 0.01) augmented BA-induced cell differentiation. Other cytokines including rhIL-1 alpha/beta, rhIL-2, rhIL-4, rhIL-6, rhIL-8, rhTNF-alpha and rhIFN-gamma had no effect on differentiation. Expression of GM-CSF and GM-CSF receptor mRNA was detected in cellular RNA obtained from BA-stimulated EoL-1 cells. Moreover, about 5-10 pg/ml of GM-CSF was detected in the culture supernatant of BA-stimulated EoL-1 cells. These findings suggested that BA-induced EoL-1 cell differentiation was elicited under the influence of GM-CSF endogenously produced in these cells. GM-CSF also seemed to be an autocrine differentiating factor in EoL-1 cells.

[A study of characteristics in adult asthmatics who are sensitized by cats and dogs allergens]

We studied adult asthmatics who were sensitized (RAST sore > or = 1) by cats and dogs allergens. Compared with non-sensitized asthmatics, the following some characteristics were noted in the sensitized asthmatics: 1) The histogram of the onset age of asthma showed two peaks. 2) The asthmatics sensitized by cats epithelium were more frequent and had higher RAST scores than those sensitized by dog hair dander. 3) There was a significant correlation between the RAST scores to dogs dander and dog hair. 4) There was no correlation between the RAST score to cat epithelium and dog hair. 5) The positive rations of intradermal testing to other allergens were higher in the sensitized asthmatics than in the non-sensitized asthmatics, especially to some foods allergens. 6) The asthmatics sensitized by cat and dog allergens were much more sensitized by house-dust mites than were the non-sensitized asthmatics. The asthmatics sensitized by cat and dog demonstrated being allergic to not only cat and dog allergens but also to many other allergens. We thought that the sensitized asthmatics were more atopic than the non-sensitized asthmatics and this was the reason why they were sensitized by cat and dog. The RAST scores to cat allergens were higher than the RAST scores to dog allergens. This fact showed that the cat was more important than the dog. This result agreed with our clinical experience.

Further characterization of dispersed human sinus mast cells

We have examined biochemical and functional characteristics of dispersed sinus mast cells and compared them with those of mast cells dispersed from other tissues. This experiment yielded the following results. 1) Although no difference was observed in histamine content, tryptase content in sinus mast cells was significantly lower than that of skin and lung mast cells. 2) In contrast with the situation in foreskin mast cells, anti-IgE-induced histamine release from sinus and lung mast cells was potentiated with lower concentrations of adenosine. 3) Similar to lung mast cells, sinus mast cells did not respond to compound 48/80 or substance P, whereas skin mast cells were stimulated to release histamine with either 10 micrograms/ml of compound 48/80 (14.0%) or 10(-4) M of substance P (23.4%). 4) Sinus mast cells are similar to lung mast cells in terms of release of arachidonic acid metabolites. Anti-IgE challenge of sinus mast cells caused the generation of both prostaglandin D2 (89.5 +/- 33.7 ng/10(6) mast cells, n = 14) and i-leukotriene D4 (78.7 +/- 46.8 ng/10(6) mast cells, n = 10).

Suppression of IgE production by IPD-1151T (suplatast tosilate), a new dimethylsulfonium agent: (1). Regulation of murine IgE response

The effect of IPD-1151T, a new dimethylsulfonium compound, on the IgE response was investigated in the mouse system. The oral administration of IPD-1151T to immunized BALB/c mice suppressed the primary IgE antibody response and depressed the elevation of serum IgE levels, whereas the same treatment did not affect the IgG antibody response. The enhanced expression of low-affinity IgE receptor (Fc epsilon RII/CD23) on the spleen cells of immunized mice was also inhibited by IPD-1151T administration. It was further demonstrated from the adoptive transfer experiment that IPD-1151T, administered to hapten-primed B cell donors, but not to carrier-primed T cell donors, exerted its suppressive influence on the hapten-specific secondary IgE antibody response in irradiated syngeneic recipients. Interestingly, IPD-1151T concentration-dependently inhibited the production of interleukin 4 (IL-4) by D10G4.1, known to be a typical Th2 clone. However, IPD-1151T did not suppress the production of IgE and IgG1 by normal splenic B cells stimulated with lipopolysaccharide and IL-4. Moreover, IL-4-induced expression of Fc epsilon RII on normal spleen cells was not inhibited by the agent. These results strongly suggest that the IgE-suppressive activity of IPD-1151T is most likely due to the inhibition of IL-4 production at the T cell level.

Suppression of IgE production by IPD-1151T (suplatast tosilate), a new dimethylsulfonium agent: (2). Regulation of human IgE response

The ability of IPD-1151T to suppress the induction of human IgE synthesis was investigated with an in vitro model of IgE production mediated by an allergen-specific helper T cell line (SN-4) from a patient allergic to Japanese cedar pollen. IPD-1151T induced a concentration-dependent suppression of purified allergen (Cry j 1)-dependent IgE synthesis in autologous B cell cultures mediated by SN-4, without significantly affecting the IgG synthesis. In addition, the production of interleukin 4 (IL-4) by Cry j 1-activated SN-4 as well as that by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) of normal donors was inhibited in a concentration-dependent manner by the agent. Interestingly, IPD-1151T clearly depressed PHA-induced expression of IL-4 mRNA in normal PBMC, indicating that this agent inhibits IL-4 gene transcription. However, IPD-1151T had no antagonistic action on IL-4, since neither IL-4-induced expression of low-affinity IgE receptor (Fc epsilon RII/CD23) on normal B cells nor soluble Fc epsilon RII release from IL-4-stimulated B cells was affected by the agent. On the other hand, IPD-1151T had no effect on the production of interferon-gamma by both Cry j 1-stimulated SN-4 and anti-CD3 monoclonal antibody-activated T cells of normal donors. These results suggest that the selective suppression of IgE synthesis by IPD-1151T results from the inhibition of IL-4 production by T cells at the gene level.

Possible role of CD5+ B cells expressing CD23 in mediating the elevation of serum-soluble CD23 in patients with rheumatoid arthritis

Since increased levels of serum soluble CD23/Fc epsilon RII (sCD23) were evidently demonstrated in patients with autoimmune diseases such as rheumatoid arthritis (RA), the possible mechanisms responsible for the elevation of serum sCD23 were investigated in RA patients. In keeping with increased serum sCD23, high proportion of CD23+ B cells was detected in the patients; this was associated with the enhanced expression of only Fc epsilon RIIa mRNA. Upon incubation at 37 degrees C, peripheral blood mononuclear cells of the patients spontaneously released high levels of sCD23 into the culture supernatant, while the CD23 expression on their B cells was considerably maintained even after the culture. Dot blot analysis further revealed that in contrast to normal subjects, RA patients showed no complete disappearance of Fc epsilon RIIa mRNA after the spontaneous culture. In addition, sCD23 release was significantly reduced in the patients by the addition of cycloheximide. It was also found that cycloheximide exerted the inhibitory influence on the spontaneous culture-mediated expression of CD23 on CD5+ but not CD5- B cells of the patients. However, the disappearance of CD23 from CD5+ as well as CD5- B cells of cord blood samples was unaffected by the agent. These results strongly suggest that CD5+ B cells of RA patients may be specifically activated by some mechanisms responsible for the persistent expression of Fc epsilon RIIa mRNA leading to the accelerated turnover of CD23 and in turn the increased release of sCD23.

[A new steroid therapy for difficult asthmatics--an induction and maintenance, two-step therapy]

Beclomethasone dipropionate (BDP) administered by inhaler is a very useful drug for the treatment of bronchial asthma. In this therapy, it is very important to use steroids systematically to induce a complete remission of asthma attack (first step) and then begin to use BDP a dose of more than 800 micrograms to maintain remission (second step). We treated 27 difficult asthmatics with this therapy and found this new method very useful. The characteristics of asthmatics were as follows. 1) The age ranged from 37 to 82, and the mean age (+/- S.E.) was 58.9 (+/- 2.6) years old. 2) The onset age ranged from 27 to 74 with a mean age (+/- S.E.) of 46.9 (+/- 2.6) year old. 3) The number of non-atopy was 22 cases. 4) The follow-up duration ranged from 5 to 45 months with a mean (+/- S.E.) of 15 (+/- 2.0) months. The results were as follows. 1) The complete remission rate was 48%, partial remission 37% and unchanged 15%. 2) There was a significant increase only in %VC. 3) The peripheral eosinophil count was decreased significantly. 4) The log value of PC20 concentration by acetylcholine increased significantly by a factor of 2.94 to 3.28. 5) After this therapy, the mean serum cortisol level at 9:00 a.m. was 10.1 (+/- 3.8, S.E.) micrograms/ml. There were only 2 cases whose cortisol level were under the normal. 6) There were many oral side effects, namely stomatitis with 5 cases and hoarseness with 8.

Orofacial pain increases mRNA level for galanin in the trigeminal nucleus caudalis of the rat

The changes of preprogalanin mRNA levels in the superficial dorsal horn neurons (laminae I and II) of the trigeminal nucleus caudalis in response to orofacial pain induced by the injection of 5% formalin into the lips of rats was investigated and compared to those of preproenkephalin A mRNA and preprodynorphin mRNA in the same region by means of in situ hybridization histochemistry. Rapid and marked increases of preprogalanin and preprodynorphin mRNA were observed on the side of the injection, but the increase of preproenkephalin A mRNA level was less pronounced than that of the other two mRNAs, indicating that these peptides have different roles in the dorsal horn analgesic mechanism and that galanin, in addition to opioid peptides, may have a highly specific role in this mechanism.

[A case of obstructive ileus following the upper Gi barium swallow study with condensed barium due to severe constipation]

A 64-year-old woman visited my clinic with complaints of abdominal distension, constipation, and nausea. Since abdominal X-ray showed severe obstructive ileus following the upper GI barium swallow study, the patient was sent immediately to Saga Medical School Hospital for the emergency operation. As the result of the left hemicolectomy, two obstructive lesions were found at the sigmoid colon and the transverse colon. Nowadays, as the population of aged people increases and Japanese diet changes, colon cancers are increasing more rapidly. Since the half of colon cancers doesn't have any clinical symptoms of obstruction, the upper GI barium swallow study with condensed barium might lead a patient to some type of dangerous situation.

PAF-induced eosinophilic and basophilic differentiation in human hematopoietic precursor cells

PAF enhances the maturation and differentiation of basophils and eosinophils from hematopoietic precursor cells. These enhancing effects of PAF were inhibited by PAF antagonists, such as WEB-2086. Also, the coexistence of antibodies to IL-1 and IL-3 markedly inhibited the PAF-induced differentiation. Human recombinant IL-1 alpha/beta induced differentiation of hematopoietic precursor cells into both cell lines, and this was completely inhibited by the coexistence of antibody to IL-3. Interleukin 1 beta and IL-3 were detected in the cultured supernatant of PAF-stimulated mononuclear leukocytes obtained from human umbilical blood. From these findings, it is suggested that PAF triggers the production of these growth factors via specific receptors, and the growth factors produced may directly cause the differentiation and maturation of the precursor cells.

Concentration of airborne mite allergens (Der I and Der II) during sleep

Using a low-noise air sampler and a sensitive radioimmunoassay, we measured the concentration of mite allergens in the air during sleeping with Japanese bedquilts (futon). The airborne allergen levels of Der I (Der p I plus Der f I) and Der II during sleep were 223 and 87.1 pg/m3 of air, respectively. These levels were about 10-fold higher than those during usual domestic life in the living room of the same houses. When the bedquilts were changed to new ones free of mite allergens, the airborne allergen levels of Der I and Der II were decreased to 11.5 and 12.0 pg/m3, respectively. This indicated that the mite airborne allergens during sleep were generated from the used bedding, not from the floor. We believe that exposure to airborne mite allergens during sleep might be an important factor in the development of mite allergies.