SAGA Complex Subunit Hfi1 Is Important in the Stress Response and Pathogenesis of Cryptococcus neoformans

The Spt-Ada-Gcn Acetyltransferase (SAGA) complex is a highly conserved co-activator found across eukaryotes. It is composed of a number of modules which can vary between species, but all contain the core module. Hfi1 (known as TADA1 in Homo sapiens) is one of the proteins that forms the core module, and has been shown to play an important role in maintaining complex structural integrity in both brewer's yeast and humans. In this study we successfully identified the gene encoding this protein in the important fungal pathogen, Cryptococcus neoformans, and named it HFI1. The hfi1Δ mutant is highly pleiotropic in vitro, influencing phenotypes, ranging from temperature sensitivity and melanin production to caffeine resistance and titan cell morphogenesis. In the absence of Hfi1, the transcription of several other SAGA genes is impacted, as is the acetylation and deubiquination of several histone residues. Importantly, loss of the gene significantly impacts virulence in a murine inhalation model of cryptococcosis. In summary, we have established that Hfi1 modulates multiple pathways that directly affect virulence and survival in C. neoformans, and provided deeper insight into the importance of the non-enzymatic components of the SAGA complex.

Remifentanil preconditioning confers delayed cardioprotection in the rat †

BACKGROUND

Preconditioning with remifentanil (RPC) provides immediate cardioprotection in rats via all three types of opioid (OP) receptor. This study sought to investigate whether remifentanil also confers delayed cardioprotection via OP receptors.

METHODS

Male rats received preconditioning either by ischaemia (IPC; 5 min occlusion, 5 min reperfusion x 3) or with remifentanil (RPC; 1, 5, 10, and 20 microg kg(-1) min(-1), 20 min infusion). After 24 h, all animals were subjected to 30 min occlusion of the left coronary artery and 2 h of reperfusion. Subsequently, the time-course effect of RPC (10 microg kg(-1) min(-1), 20 min infusion) was determined at 12, 16, 24, 32, 36, and 48 h intervals, using the same experimental procedure. The effect of RPC (10 microg kg(-1) min(-1), 20 min infusion) and IPC in the presence of selective OP receptor antagonists was evaluated at the 24 h interval. Infarct size (IS), as a percentage of the area at risk (AAR), was determined.

RESULTS

Pre-treatment with remifentanil at 1, 5, 10, and 20 microg kg(-1) min(-1) significantly reduced the IS/AAR at 24 h with the maximum effect at 10 microg kg(-1) min(-1). Remifentanil at 10 microg kg(-1) min(-1) significantly reduced the IS at 12 h [32.5 (sd 9.1)%]; 16 h [26.1 (2.8)%]; 24 h [19.5 (5.0)%]; 32 h [31.2 (9.1)%]; and 36 h [36.4 (9.4)%] after drug administration. The maximal reduction in IS was seen at 24 h and the effect completely disappeared at 48 h [36.4 (9.4)%]. The protective effect of RPC was abolished or significantly attenuated by blockade of any of the three OP receptors with selective antagonists.

CONCLUSIONS

Like IPC, remifentanil produces delayed cardioprotection in anaesthetized rats 12-36 h after administration. The protective effect is mediated via all three OP receptors.

A Non-biotin Polymerized Horseradish-peroxidase Method for the Immunohistochemical Diagnosis of Canine Distemper

This report describes a modified non-biotin polymerized horseradish peroxidase (HRP) immunohistochemical method for the diagnosis of canine distemper virus (CDV) infection from formalin-fixed, paraffin wax-embedded tissues. This method confirmed infection in seven of eight (87.5%) suspected cases. Labelled CDV antigen was observed in the following sites: cerebrum, cerebellum, meninges, glial cells, neurons, vascular endothelium, periventricular areas and pericytes, and choroid plexus; grey and white matter and central canal of the spinal cord; renal pelvis and tubular epithelium, and urinary bladder epithelium; macrophages and lymphocytes in splenic white pulp and lymph nodes; skin epidermis; bronchiolar epithelium and alveolar macrophages; hepatic Kupffer cells, and gastric and intestinal mucosal epithelium; stratified squamous epithelium of the tongue and oesophagus. With the non-biotin HRP detection system, pretreatment by autoclaving followed by microwave heating gave better labelling results than did microwave pretreatment alone. No obvious difference was noted between the labelling results produced by the non-biotin HRP detection system and the Super Sensitive Link-Label IHC detection system.

Delayed diagnosis of cervical cancer in young women

This study aims to determine whether women under 35 years presenting with cervical cancer experience delays between presentation and diagnosis. All women referred with cervical cancer to the gynaecological cancer centre for the North London Cancer Network from January 2002 to December 2004 were identified retrospectively. Clinical presentation and time interval from symptoms to diagnosis were compared between women under and women over 35 years. A total of 105 women were included. Median age at diagnosis was 45 years (range 23--88). Twenty-two women (19%) were under 35 years at presentation and 17 had persistent symptoms prior to diagnosis. Median time from initial presentation to diagnosis in this group was 9 months (range 3--24 months); significantly longer than in the older group (9 vs 2 months; p=0.0009). Although cervical cancer is relatively rare in young women, diagnosis should be considered in symptomatic women as delay can limit treatment options.

Multicenter screening for pre-eclampsia and fetal growth restriction by transvaginal uterine artery Doppler at 23 weeks of gestation

OBJECTIVE

To determine the value of transvaginal color Doppler assessment of the uterine arteries at 23 weeks of gestation in predicting the subsequent development of pre-eclampsia and fetal growth restriction.

PATIENTS AND METHODS

Women with singleton pregnancies attending for routine ultrasound examination at 23 weeks in any one of seven hospitals underwent Doppler assessment of the uterine arteries. The presence of an early diastolic notch in the waveform was noted, and the mean pulsatility index of the two arteries was calculated. Screening characteristics in the prediction of pre-eclampsia and the delivery of a low birth-weight infant were calculated.

RESULTS

Doppler examination of the uterine arteries was attempted in 8335 consecutive singleton pregnancies, satisfactory waveforms were obtained from both vessels in 8202 (98.4%) cases and complete outcome data were available in 7851 (95.7%) of these. The mean gestational age was 23 (range, 22-24) weeks. The mean uterine artery pulsatility index did not change significantly with gestation (r = -0.0078; P = 0.483); the median value was 1.04 and the 95th centile was 1.63. In 9.3% of cases early diastolic notches in the waveform from both uterine arteries were present and in an additional 11.1% of cases there were notches unilaterally. Pre-eclampsia with fetal growth restriction occurred in 42 (0.5%) cases, pre-eclampsia without fetal growth restriction in 71 (0.9%) and fetal growth restriction without pre-eclampsia in 698 (8.9%). The sensitivity of increased pulsatility index above the 95th centile (1.63) for pre-eclampsia with fetal growth restriction was 69%, for pre-eclampsia without fetal growth restriction was 24%, for fetal growth restriction without pre-eclampsia was 13%, for pre-eclampsia irrespective of fetal growth restriction was 41% and for fetal growth restriction irrespective of pre-eclampsia was 16%. The sensitivity of fetal growth restriction defined by the 5th rather than the 10th centile was higher (19% vs. 16%). The sensitivity for both pre-eclampsia and fetal growth restriction was inversely related to the gestational age at delivery; when delivery occurred before 32 weeks, the sensitivity for all cases of pre-eclampsia with fetal growth restriction, pre-eclampsia without fetal growth restriction and fetal growth restriction without pre-eclampsia increased to 93%, 80% and 56%, respectively. The sensitivity of bilateral notches in predicting pre-eclampsia and/or fetal growth restriction was similar to that of increased pulsatility index but the screen-positive rate with notches (9.3%) was much higher than that with increased pulsatility index (5.1%).

CONCLUSIONS

A one-stage color Doppler screening program at 23 weeks identifies most women who subsequently develop severe pre-eclampsia and/or fetal growth restriction.

Repeatability of measurement of uterine artery pulsatility index using transvaginal color Doppler

OBJECTIVE

To assess the repeatability of measuring the pulsatility index of the uterine arteries using transvaginal color Doppler at 23 weeks of gestation.

PATIENTS AND METHODS

The pulsatility index was measured in 100 women with singleton pregnancies attending for routine transvaginal Doppler examination of the uterine arteries at 23 weeks. To assess the repeatability of different components of variability, six measurements of the uterine artery pulsatility index were made on one of the uterine arteries in each patient.

RESULTS

Six measurements of the pulsatility index were successfully measured in all 100 patients, resulting in a total of 600 measurements. The repeatability was unrelated to the pulsatility index. On 95% of occasions the intraobserver, interobserver and waveform tracing repeatability was less than 0.24, 0.27 and 0.14, respectively.

CONCLUSIONS

Measurement of the pulsatility index using transvaginal color Doppler is highly reproducible when the examination is carried out by well-trained operators.

Complete genome analysis of enterovirus 71 isolated from an outbreak in Taiwan and rapid identification of enterovirus 71 and coxsackievirus A16 by RT-PCR

Hand, foot, and mouth disease (HFMD) and encephalomyelitis were two major clinical manifestations during the 1998 enterovirus 71 (EV71) epidemic in Taiwan. To investigate whether different clinical patterns were caused by alterations in EV71 genomes, the complete nucleotide sequences of four EV71 strains associated with HFMD or encephalomyelitis were compared. Among these viral strains, two or three nucleotide differences were found within the 5'-noncoding region, and two or four amino acid differences were found within the regions encoding viral polyproteins; however, none of these differences were correlated with either clinical manifestation. Because coxsackievirus A16 was another major causative agent of HFMD, a reverse transcription-polymerase chain reaction assay, with high sensitivity and specificity for identification of EV71 (both 100%) and coxsackievirus A16 (100 and 98.8%), was developed for the rapid differential identification of these two viruses in HFMD patients.

Isolation and characterization of a Vibrio vulnificus mutant deficient in both extracellular metalloprotease and cytolysin

We isolated a Vibrio vulnificus mutant that was deficient in both metalloprotease and cytolysin by allelic exchange. The virulence of this mutant in mice and its cytotoxicity for HEp-2 cells were comparable to those of the wild-type strain, indicating that neither factor was essential for these properties. The cytolysin, but not the protease, seemed to be important for causing damage in the alimentary tract of the mice.

Allergen-induced bronchial inflammation is associated with decreased levels of surfactant proteins A and D in a murine model of asthma

BACKGROUND

Increasing evidence suggests that pulmonary surfactant protein A (SP-A) and D (SP-D) participate in the lung defence against pathogens. However, the role of surfactant proteins in the pathogenesis of allergen-induced airway inflammation has not been elucidated. In this study we examined the levels and distributions of SP-A and SP-D in a dust mite (Dermatophagoides pteronyssinus, Der p) allergen-induced murine model of asthma.

METHODS

The concentration of SP-A and SP-D in the bronchoalveolar lavage fluid (BALF) and the distribution of surfactant proteins in the lung were assayed by ELISA and immunohistochemistry methods, respectively. The effect of surfactant proteins on allergen-induced pulmonary lymphocyte proliferation was also studied.

RESULTS

We demonstrated that there were marked reductions of SP-A and SP-D levels in the BALF of Der p-sensitized BALB/c mice at 48-72 h after allergen challenge (AC). Both purified SP-A and SP-D were able to suppress, in a dose dependent manner, Der p-stimulated intrapulmonary lymphocyte proliferation of naïve mice with saline or allergen challenge, or of Der p-sensitized mice with saline challenge. On the contrary, this suppressive effect was mild (< 9%) on lymphocytes from sensitized mice after AC.

CONCLUSION

These results indicated the involvement of pulmonary surfactant proteins in the allergic bronchial inflammation of sensitized mice.

The effect of Chinese herbal medicine, xiao-qing-long tang (XQLT), on allergen-induced bronchial inflammation in mite-sensitized mice

BACKGROUND

There are detailed descriptions of the clinical experiences and prescriptions of asthma in traditional Chinese medicine. Xiao-qing-long tang (XQLT), or sho-seiryo-to by its Japanese name, is one of the Chinese herbal medicines used to treat bronchial asthma and allergic rhinitis for centuries. However, the therapeutic mechanisms of this medication are still far from clear. In this study, a house-dust-mite (Dermatophagoides pteronyssinus [Der p])-sensitized murine model of asthma was used to evaluate the immunomodulatory effect of XQLT on the allergen-induced airway inflammation in asthma.

METHODS

Three different protocols were designed to evaluate the treatment and/ or long-term prophylactic effect of XQLT in Der p-sensitized mice. XQLT extracts (1 gm/kg) were administered to sensitized mice 1 h before allergen challenge (AC) (group A), 24 h after AC (group B), and every other day six times before AC (group C), respectively. Cellular infiltration and T-cell subsets in the bronchoalveolar lavage fluid (BALF) of allergen-challenged mice were analyzed. Intrapulmonary lymphocytes were also isolated to evaluate their response to allergen stimulation.

RESULTS

When XQLT was administered to the sensitized mice before AC (groups A and C), it suppressed airway inflammation by decreasing the number of total cells and eosinophil infiltration in the BALF, and downregulated the allergen- or mitogen-induced intrapulmonary lymphocyte response of sensitized mice as compared to those of controls. This immunomodulatory effect of XQLT may be exerted through the regulation of T-cell subsets by elevation or activation of the CD8+ and double-negative T-cell population in the lung. However, the administration of XQLT to sensitized mice 24 h after AC (group B) did not have the same inhibitory effect on the airway inflammation as XQLT given before AC.

CONCLUSIONS

The administration of XQLT before AC has the immunomodulatory effect of reducing bronchial inflammation in the allergen-sensitized mice.

Neutralizing antibody provided protection against enterovirus type 71 lethal challenge in neonatal mice

Experimental infection with enterovirus type 71 (EV71) induced death in neonatal mice in an age- and dose-dependent manner. The mortality rate was 100% following intraperitoneal inoculation 1-day-old ICR mice and this gradually decreased as the age at the time of inoculation increased (60% in 3-day-old mice and no deaths occurred in mice older than 6 days of age). A lethal dose greater than 10(8) PFU was necessary. Lethargy, failure to gain weight, rear limb tremors and paralysis were observed in the infected mice before death. EV71 was isolated from various tissues of the dead mice. Using a reverse transcription polymerase chain reaction technique with a specific primer pair, a 332-bp product was detected in the tissues that produced a culture positive for EV71. Protection against EV71 challenge in neonatal mice was demonstrated following passive transfer of serum from actively immunized adult mice 1 day after inoculation with the virus. Pups from hyperimmune dams were resistant to EV71 challenge. Additionally, maternal immunization with a formalin-inactivated whole-virus vaccine prolonged the survival of pups after EV71 lethal challenge.

Propionibacterium acnes induces acute TNFalpha-mediated apoptosis of hepatocytes followed by inflammatory T-cell-mediated granulomatous hepatitis in mice

The CD3+/TCRalphabeta+ T-cell-mediated hepatic inflammation induced by Propionibacterium acnes could be divided into an acute and a chronic phase. The acute phase occurred within 72 h after injection and displayed hepatic apoptosis. Anti-TNFalpha antibody inhibited both the P. acnes-induced hepatic apoptosis and lymphocyte infiltration seen in this phase, indicating the involvement of this cytokine. Thereafter, a chronic phase was manifested from days 7 to 14 after injection. It was characterized as granulomatous inflammation admixed with apoptosis of infiltrating lymphocytes and some hepatocytes. Immunohistochemical staining showed that the infiltrating lymphocytes displayed TNFalpha, TNF type I receptor and a variety of cytokines including IL-1beta, IL-4, IL-6, IL-10, IFNgamma or IL-12. Interestingly, in naive mice, the arteries in the liver constitutively expressed IFNgamma. Its expression appeared to be substantially increased at 48 h, decreased at 72 h, and increased again on day 14 after P. acnes injection. Furthermore, Fas or FasL was only detected on the lymphocytes within the granuloma. We conclude that P. acnes can induce a TNFalpha-mediated acute hepatic apoptosis which subsequently progress to a T-cell-mediated granulomatous hepatitis with increased expression of multiple cytokines and Fas/FasL.

Repeated intratracheal inoculation of house dust mite (Dermatophagoides farinae) induces pulmonary eosinophilic inflammation and IgE antibody production in mice

BACKGROUND

In vitro studies have shown that the biologic activities of dust mite allergens probably contribute to their allergenicity. However, little is known about their in vivo effect, which may lead to allergic inflammation and sensitization.

OBJECTIVE

In this study we characterized the pathologic and immunologic responses of mice after repetitive challenge with dust mite Dermatophagoides farinae.

METHODS

Der f crude extract was intratracheally instilled into female BALB/c mice either once or a total of 10 times at 1-week intervals. The inflammatory responses, morphologic changes, IgE antibody and cytokine levels, and costimulatory molecular B7 expression in the airways were then monitored.

RESULTS

We demonstrated that single Der f challenge provoked an acute neutrophilic inflammation in the airways. After repeated Der f challenge, there was chronic inflammation characterized by increased numbers of lymphocytes and eosinophils in bronchoalveolar lavage (BAL) fluids. Histopathologically, the numbers of goblet cells and mast cells were significantly increased in the airways of these mice. Repetitive challenge elicited Der f-specific IgE antibody, increased IL-5 and IFN-gamma level in BAL fluids, and enhanced costimulatory B7 molecule expression on BAL cells.

CONCLUSIONS

Our findings are in agreement with those of other in vitro studies concerning the properties of dust mite allergens. Prolonged inhalation of Der f without adjuvant may represent an optimal condition to develop experimental animal models of allergic lung diseases.

Attenuation of house dust mite Dermatophagoides farinae-induced airway allergic responses in mice by dehydroepiandrosterone is correlated with down-regulation of TH2 response

BACKGROUND

Dehydroepiandrosterone (DHEA), an abundant androgen in circulation, has important immunomodulating effects on T-cell differentiation; however, it is not known whether this hormone influences allergic responses.

OBJECTIVE

We have established a murine model of airway inflammation induced by house dust mite Dermatophagoides farinae (Der f). Der f challenge of sensitized mice would elicit a pulmonary eosinophilic inflammation. In the present study, we employed this model system to explore the effect of DHEA on allergic responses.

METHODS

Female BALB/c mice were fed with a standard diet incorporated with 1.5% (w/w) of DHEA for 1 week before sensitization and every other day for an additional 2 weeks after sensitization. After intratracheal inoculation of allergen, the Der f-induced airway inflammation, immunoglobulin (Ig)E antibody production, and cytokine expression were compared between control and DHEA-fed mice.

RESULTS

In control mice the Der f-induced eosinophilia in bronchoalveolar lavage (BAL) fluids was accompanied by an increase in production of interleukin (IL)-4, IL-5, and interferon IFN-gamma systemically and locally. DHEA supplementation did not affect the body weight of mice. However, in mice that were receiving DHEA, the numbers of eosinophils and lymphocytes in BAL fluids significantly decreased at days 2 and 6 after challenge as compared with control mice. Concomitantly, total IgE antibody concentrations as well as IL-4, IL-5, and IFN-gamma levels in BAL fluids or serum also significantly reduced. Immunocytochemical staining of BAL cells revealed that there were fewer IL-4-, IL-5-, IL-10-, but not IFN-gamma-positive stained cells in DHEA-fed mice than in mice who consumed unsupplemented diet. Reverse transcription-polymerase chain reaction analysis demonstrated DHEA decreased the expression of IL-5 and IL-10 transcripts in BAL cells.

CONCLUSIONS

Our results showed that administration of DHEA during allergic sensitization could attenuate the subsequent allergic responses elicited by challenge, and that the suppressive effect of DHEA was associated with a down-regulation of TH2 response.

Exogenous dehydroepiandrosterone modified the expression of T helper-related cytokines in NZB/NZW F1 mice

The onset of lupus-like disease in NZB/NZW F1 mice was correlated with the expression of IL-10 at 4 m of age, and with a sequential enhanced expression of IFN-gamma and IL-6 between 6 to 8 m of age. The expression of IFN-gamma and IL-6 was associated with exacerbation of disease symptom, production of anti-DNA antibody, and increase in total serum IgG1. Exogenous dehydroepiandrosterone (DHEA) given in animal diet significantly prolonged survival, and delayed formation of autoantibody of NZB/NZW F1 mice as compared to mice fed on control diet. The effect of DHEA paralleled a delay in the expression of IL-10 and IL-6 and an earlier detection of IL-12 transcripts. Moreover, DHEA-fed mice had higher serum IgG2a level than control diet-fed mice. Collectively, DHEA may modify the activation of distinct subset of T helper cells in NZB/NZW F1 mice at different phases of disease progression.

Women's attitudes to and awareness of smear testing and cervical cancer

A cross sectional survey consisting of a questionnaire of 650 randomly selected women aged 15 to 78 years was performed to gain an insight into women's attitudes to and awareness of smear testing and cervical cancer. Their general health and screening history were noted along with their knowledge of the smear test and cervical cancer. Of the respondents, 80.5 per cent had had at least one smear test and 71.5 per cent of these women have regular smears. The majority of the women (66.9 per cent) thought the test 'no problem' and those who found the test 'embarrassing, painful or troublesome' were of a younger age group. Overall, 76.2 per cent perceived the disease to be a common one. 32.6 per cent of the respondents thought the age group 40s to 50s to be most affected by cervical cancer. On the whole, women appeared to be well informed of the link between the number of sexual partners and cervical cancer as well as recognising smoking to be a contributing factor. A substantial proportion (91.7 per cent) of women were of the attitude that cancer can be treated if detected early enough. The perceived barrier such as embarrassment and discomfort played a part in women's decision in returning for a regular smear. By influencing the awareness and perceptions through public health education as well as creating an appropriate environment for the test, this can indeed help to reduce personal perceived barriers and increase the uptake of smear testing.

Dermatophagoides-farinae-induced pulmonary eosinophilic inflammation in mice

Dermatophagoides farinae (Der f) is one of the most common species of dust mites that induce asthma and allergic rhinitis. We have reported that Der f challenge on sensitized mice elicited a distinct type of hypersensitivity, called early-type hypersensitivity (ETH), in subcutaneous tissues and in airways. The airway ETH was accompanied by a series of inflammatory and immunological events including cytokine production, adhesion molecule expression, inflammatory cell infiltration, eosinophilia, and airway hyperreactivity. In the present study, we further defined the course of the Der-f-induced eosinophilia and examined the local cytokine gene expression and the roles of cytokines, mast-cell-derived vasoactive amines, and corticosteroids in the development of pulmonary eosinophilia. BALB/c mice were sensitized with crude extract of Der f in complete Freund's adjuvant and were intranasally challenged with Der f on day 14 after sensitization. The number of blood eosinophils, total and differential leukocyte counts in bronchoalveolar lavage (BAL) fluids, and the expression of cytokine genes in BAL cells were assessed at various time points after challenge for up to 12 days. The total number of leukocytes in the BAL fluids was increased 6 h after challenge (AC) and peaked at 72 h. The early cellular response in the BAL fluids was dominated by neutrophils which were subsequently replaced by a marked infiltration of eosinophils. The number of eosinophils in BAL fluids increased at 24 h and peaked at 72 h, making up 43% of all cells recovered by BAL. BAL eosinophils declined gradually to normal background levels around day 12. Concurrently, there was a significant reduction in the number of eosinophils in blood 24 h AC. The number of blood eosinophils increased thereafter, reached a peak at 72 h, and remained above baseline level for up to 10 days. Saline challenge did not induce eosinophilia in BAL fluids and blood of sensitized mice. Histopathological examination revealed a mixed granulocytic, monocytic pulmonary inflammation with a large number of eosinophils accumulating within the submucosa of the airways and blood vessels of sensitized mice after challenge. Der f challenge induced a sequential expression pattern of eight cytokine genes in BAL cells. The mRNA of interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha strongly expressed throughout the course of the experiment. The IL-6 mRNA expression peaked at 0.5-72 h, IL-10 at 1-6 and 48-72 h, IL-4 at 6-72 h, IL-2 at 6-96 h, IL-5 at 24-72 h, and interferon-gamma at 24-96 h. Intraperitoneal injection of sensitized mice with monoclonal antibody (mAb) to murine IL-5 (TRFK5, 300 micrograms/mouse) 1 h before challenge caused 62% suppression of eosinophils in the BAL fluids. The concomitant accumulation of neutrophils and mononuclear cells, however, was not affected by this treatment. On the other hand, intranasal administration of mAb to murine TNF-alpha (MP6-XT3, 20 micrograms/ mouse), but not IL-5, 1 h before challenge and 24 h AC significantly reduced the numbers of eosinophils, neutrophils, and lymphocytes in the BAL fluids. The intraperitoneal injection of dexamethasone (50 mg/kg) for a total of four times resulted in total inhibition of the Der-f-induced cellular responses, whereas vasoactive amine antagonists (diphenhydramine, ketanserin and cyprohepatidine) did not show any effect.

Early-type hypersensitivity-associated airway inflammation and eosinophilia induced by Dermatophagoides farinae in sensitized mice

In a murine ear-swelling model, we demonstrated a unique hypersensitivity response and defined it as early-type hypersensitivity (ETH). ETH was characterized by increased vasopermeability and edematous change that occurred within 1 h at the site of Ag challenge. In this study, intranasal challenge with Dermatophagoides farinae (Df) on Df-sensitized BALB/c mice induced an ETH response in the lungs. The lung ETH was manifested by an increase in wet lung weight, production of TNF-alpha in bronchoalveolar lavage fluids, and hyperemia and edematous change around vessels of small airways 1 h after Ag provocation. The challenged animals subsequently developed airway inflammation, beginning with a neutrophilic infiltrate which was followed by lymphocytes and eosinophils. The Df-induced eosinophilia was Ag-specific and maximal at 48 h after challenge. At this time, the trachea from sensitized mice also exhibited hyperreactivity to carbachol. Pretreatment with anti-CD4+ mAb significantly decreased the recruitment of eosinophils in bronchoalveolar lavage fluids. An enhanced expression of pulmonary endothelial vascular cell adhesion molecule-1 was noted as early as 6 h after challenge. Anti-Df Abs of IgG class, but not IgE class, were detected in Df-immunized mice at the time of challenge. Furthermore, Df challenge induced a stronger eosinophil response in BALB/c mice (H-2d) than in B10.BR (H-2k) mice. B10.BR mice also did not exhibit pulmonary edema or ETH of ear swelling 1 h after challenge. These data suggest that an ETH-associated 1 h pulmonary edematous change was induced by intranasal challenge of Df in Df-sensitized mice, and that the ETH might contribute to the development of subsequent pulmonary inflammation and eosinophilia.

Early-type hypersensitivity-associated airway inflammation and eosinophilia induced by Dermatophagoides farinae in sensitized mice

In a murine ear-swelling model, we demonstrated a unique hypersensitivity response and defined it as early-type hypersensitivity (ETH). ETH was characterized by increased vasopermeability and edematous change that occurred within 1 h at the site of Ag challenge. In this study, intranasal challenge with Dermatophagoides farinae (Df) on Df-sensitized BALB/c mice induced an ETH response in the lungs. The lung ETH was manifested by an increase in wet lung weight, production of TNF-alpha in bronchoalveolar lavage fluids, and hyperemia and edematous change around vessels of small airways 1 h after Ag provocation. The challenged animals subsequently developed airway inflammation, beginning with a neutrophilic infiltrate which was followed by lymphocytes and eosinophils. The Df-induced eosinophilia was Ag-specific and maximal at 48 h after challenge. At this time, the trachea from sensitized mice also exhibited hyperreactivity to carbachol. Pretreatment with anti-CD4+ mAb significantly decreased the recruitment of eosinophils in bronchoalveolar lavage fluids. An enhanced expression of pulmonary endothelial vascular cell adhesion molecule-1 was noted as early as 6 h after challenge. Anti-Df Abs of IgG class, but not IgE class, were detected in Df-immunized mice at the time of challenge. Furthermore, Df challenge induced a stronger eosinophil response in BALB/c mice (H-2d) than in B10.BR (H-2k) mice. B10.BR mice also did not exhibit pulmonary edema or ETH of ear swelling 1 h after challenge. These data suggest that an ETH-associated 1 h pulmonary edematous change was induced by intranasal challenge of Df in Df-sensitized mice, and that the ETH might contribute to the development of subsequent pulmonary inflammation and eosinophilia.

Detection of airway CO2 partial pressure to avoid esophageal intubation

During endotracheal intubation, checking the position of endotracheal tube is important in order to avoid accidental esophageal intubation. Exhaled CO2 pressures of 50 emergent intubation attempts were recorded in our pediatric intensive unit to evaluate the efficacy of capnography in the early detection of esophageal intubation. Adjustment of the tube position was performed when indicated. In successful endotracheal intubation, the end-tidal CO2 pressures (PetCO2) ranged from 10 mmHg to 80 mmHg with typical respiratory phasic waveforms. In cases of inadvertent esophageal intubation, the PetCO2 values were less than 5 mmHg and revealed no typical respiratory pattern. It was also observed that PetCO2 decreased during one lung intubation or when the tip of endotracheal tube was pulled above the glottis. Capnographic monitoring end-tidal CO2 pressure continuously may be a reliable, time-saving tool for the detection of inadvertent esophageal intubation and the evaluation of proper positioning of the endotracheal tube.

Distinct regulation of humoral and cellular immunities to hepatitis B surface antigen

The surface envelope protein of hepatitis B virus (HBsAg) stimulates the immune system to produce anti-HBs antibodies and to generate cell-mediated immunity. These two arms of immunity were found to be regulated differently in bm12 (H-2bm12) or CBA and C3H (H-2k) mice. In bm12 mutant (I-A beta mutant of B6 mice) mice, the anti-HBs production, early-type, and immune complex-type hypersensitivity were impaired, but the delayed-type hypersensitivity and the T-cell proliferation in vitro were normal compared to the parental B6 (H-2b) mice. The mutation of the A beta molecule seems to affect the immune responses differentially. On the other hand, C3H or CBA mice produced anti-HBs antibodies after major S protein (pre-S-depleted HBsAg) stimulation, but could not generate the hypersensitivity responses. The pre-S region could circumvent the non-responsiveness of the hypersensitivity response in C3H and CBA mice. These data suggest that the humoral and cellular immunities to the HBsAg particle are regulated distinctly and are affected by either the A beta molecule of the host or the pre-S region of the HBsAg.

Novel studies on a "silent" high affinity mutant hemoglobin (San Diego, beta 109 Val replaced by Met)

A patient with a "silent" mutant hemoglobin characterized by high oxygen affinity and erythrocytosis is described. A novel approach was used to identify the mutant chain. Functionally active alpha and beta chains were prepared from hemolysates of the patient and a normal control. Hybrid tetramers of patient's beta chain were prepared. Functional studies revealed that the patient's beta chains had a higher oxygen affinity (P50, 1.1 torr) than normal beta chains (P50, 1.7 torr) and the hybrid containing the patient's beta chains had a P50 similar to the patient's "stripped" hemolysate. It was assumed therefore that the mutation was in the beta chain; structural studies using cyanogen bromide cleavage revealed that the patient had Hb San Diego, beta 109 Val replaced by Met, and that the patient's cells contained approximately 50 percent mutant hemoglobin.

Ultraviolet light-induced division delayed in synchronized Chinese hamster cells

The age-dependent, ultraviolet light (UVL) (254 nm)-induced division delay of surviving and nonsurviving Chinese hamster cells was studied. The response was examined after UVL exposures adjusted to yield approximately the same survival levels at different stages of the cell cycle, 60% or 30% survival. Cells irradiated in the middle of S suffered the longest division delay, and cells exposed in mitosis or in G(1) had about the same smaller delay in division. Cells irradiated in G(2), however, were not delayed at either survival level. It was further established, after exposures that yielded about 30% survivors at various stages of the cycle, that surviving cells had shorter delays than nonsurvivors. This difference was not observed for cells in G(2) at the time of exposure; i.e., neither surviving nor nonsurviving G(2) cells were delayed in division. The examination of mitotic index vs. time revealed that most cells reach mitosis, but all of the increase in the number of cells in the population can be accounted for by the increase of the viable cell fraction. These observations suggest strongly that nonsurviving cells, although present during most of the experiment, are stopped at mitosis and do not divide. Cells in mitosis at the time of irradiation complete their division, and in the same length of time as unirradiated controls. Division and mitotic delays after UVL are relatively much larger than after X-ray doses that reduce survival to about the same level.

Mitotic delay and chromosomal aberrations induced by X rays in synchronized Chinese hamster cells in vitro

Synchronized Chinese hamster cell populations in vitro were X-irradiated at different stages of the cell cycle and examined at the next metaphase. Mitotic delay varied according to the stage of the cell cycle at the time of irradiation. It was greatest for cells irradiated in middle to late S, moderate for cells irradiated in G2, and least for cells irradiated in G1. It increased approximately linearly with dose (0.7 hr./100 rad for S cells and 0.3 hr./100 rad for G1 cells). Chromosomal aberration rates also depended on the stage of the cell cycle at which the cells were irradiated. Chromatid aberrations were induced mostly during G2 and S (more in early S than late S), while chromosome aberrations were induced mainly in G1. Total breaks after 500 or 750 R showed a minimum frequency in late S and a maximum frequency in G2. This form of response correlates, but only in a general qualitative way, with the dependence of survival on cell cycle stage previously reported. Mitotic delay has a dependence on cell cycle stage quite different from either chromosomal aberrations or survival.