Extent of self-adjustment to AF in exercise capacity evaluates significance of sinus maintenance and determines suitability of sinus maintenance therapy in patients with persistent AF

 

Atrial fibrillation (AF) causes hemodynamic inefficiency and possibly deteriorates to heart failure (HF). However, we have experienced drastic variances in the extent of HF deterioration in persistent AF (PeAF) patients. Some studies showed that newly developed PeAF (New AF), not preexisting PeAF adversely impacted HF patients in two years. These issues suggest that most PeAF patients gradually adjust to AF-induced hemodynamic inefficiency, however the extent of self-adjustment to PeAF differs among patients. We hypothesized that the extent of the self-adjustment might determine the adverse impact of New AF on patients. We proposed that especially New AF patients with poor adjustment to PeAF should be targeted for aggressive sinus rhythm (SR) maintenance through catheter ablation (RFCA). We considered exercise capacity (EC) of PeAF patients as the extent of the self-adjustment to PeAF. Consequently, we sought to investigate whether EC testing (CPX) in PeAF patients could be used as a determinant for suitability of aggressive SR maintenance therapy in PeAF patients.

Subjects & Method: We performed CPX to evaluate Peak VO2 intake (PVO2) at baseline for 196 consecutive PeAF patients undergoing RFCA (male: 151, female: 45). After >6 months SR-maintenance, CPX was repeated. %PVO was calculated by standardizing PVO to age and gender. During RFCA, Swan-Ganz catheter study was done to monitor changes in hemodynamics before and after RFCA. Echocardiography was done at baseline, 6 months after SR maintenance.

Results

%PVO varied from 38 to 175% before RFCA. %POV2 of NYHA 3 class patients was 76.8±17.7%. PeAF patients with 80% and more of %PVO2 seemed adjusted to AF in terms of exercise capacity. In this study we defined PeAF patients below 80% PVO2 as Non-adjusted. Out of 196 patients, 149 undertook CPX again. Changes in %PVO2 ranged from −38% to 48% (median: 7.0%). According to multi-regression analysis of changes in %PVO, PeAF patients with Non-adjustment (β=0.31), greater increase in HR during repeated CPX (β=0.40), larger reduction in E/e (β=−0.21) after SR maintenance, obtained larger improvement in EC. Particularly, Non-AF adjustment in PeAF patients was the sole predictor of improvement in EC after RFCA.

Furthermore, we sought to identify the determinants of Non-AF adjustment in PeAF patients. Multivariate logistic analysis demonstrated that female patients became Non-adjusted significantly more easily than male (p<0.001). Increase in HR during CPX was the most important factor for adjustment to PeAF. In males, poor LV diastolic function, higher Pulmonary vascular resistance were also negative predictors for adjustment to PeAF. However, there is concern about deterioration in EC for patients with chronotropic incompetence revealed after RFCA.

Conclusion

The extent to which PeAF patients could adjust to AF helps in evaluating the significance of SR-maintenance and determining the suitability of aggressive SR-maintenance therapy.

Funding Acknowledgement

Type of funding source: None

P924Prognostic significance of moderate primary mitral regurgitation and atrial fibrillation

Background

Severe primary mitral regurgitation [degenerativeMR (DMR)] is associated with poor outcome, including cardiac death and admission due to worsening heart failure. Whereas little information is available regarding the characteristics of moderate DMR and their impact on prognostic outcome.

The aim of the present study was to investigate the prognosis and its determinant in patients with moderate DMR.

Methods

From 13,700 consecutive patients who underwent transthoracic echocardiography. We selected moderate DMR but without other underlying cardiac diseases. Characteristics and event free rate as compared with age- and gender-matched patients with none to mild MR.

Results

Of a total of our cohort, 185 (1%) patients had moderate DMR, and we compared with 185 age- and gender-matched patients with none to mild MR. During the follow-up period of 1372±655 days, 30 patients (8%) met the composite endpoint defined as cardiac death and admission due to worsening heart failure. Kaplan-Meier analysis showed patients with moderate DMR was significantly associated with a poor outcome compared to patients with none to mild MR (log-ranktest P<0.0001). Cox proportional hazard ratio revealed thatmoderate MR and atrial fibrillation (AF) were the independent predictors of the composite endpoint.

Prgnostic outcome: AF and moderate DMR

Conclusions

Patients withmoderate DMR and concomitant AF had a significant poor outcome. An activesurveillance and some intervention for AF and moderate MR may be required.

Quantitative Analysis of Conebeam CT for Delineating Stents in Stent-Assisted Coil Embolization

BACKGROUND AND PURPOSE

Innovative techniques and device-related advances have improved the outcomes of neuroendovascular treatment. 3D imaging has previously used 2 × 2 binning, but 1 × 1 binning has recently been made available. The aim of this study was to evaluate the quantitative ability of conebeam CT for stent delineation and to investigate its effectiveness in the clinical environment.

MATERIALS AND METHODS

Four acquisition groups of 3D MIP images acquired using conebeam CT with varying conditions (acquisition time, 10 or 20 seconds and binning, 1 × 1 or 2 × 2) were compared. Two methods of analysis were performed, a phantom study and an analysis of 28 randomly selected patients. The phantom study assessed the contrast-to-noise ratio and full width at half maximum values in conebeam CT images of intracranial stent struts. In the clinical subjects, we assessed contrast-to-noise ratio, full width at half maximum, and dose-area product.

RESULTS

In the phantom study, the contrast-to-noise ratio was not considerably different between 10- and 20-second acquisition times at equivalent binning settings. Additionally, the contrast-to-noise ratio at equivalent acquisition times did not differ considerably by binning setting. For the full width at half maximum results, equivalent acquisition times differed significantly by binning setting. In the clinical analyses, the 10-second/1 × 1 group (versus 20 second/2 × 2) showed a higher contrast-to-noise ratio (P < .05) and a dose-area product reduced by approximately 70% (P < .05), but the difference in full width at half maximum was not significant (P = .20).

CONCLUSIONS

For stent-assisted coil embolization, quantitative assessment of conebeam CT showed that 10 second/1 × 1 was equivalent to 20 second/2 × 2 for imaging deployed intracranial stents. Furthermore, the 10-second/1 × 1 settings resulted in a much smaller DAP.

Bcl6 in pulmonary epithelium coordinately controls the expression of the CC-type chemokine genes and attenuates allergic airway inflammation

BACKGROUND

There is synteny in the CC-type chemokine gene clusters between humans (CCL2/MCP-1, CCL7MCP-3, CCL11/eotaxin, CCL8/MCP-2, CCL13/MCP-4, and CCL1/I-309) and mice (CCL2, CCL7, CCL11, CCL12/MCP-5, CCL8, and CCL1).

OBJECTIVE

As many putative Bcl6/STAT-binding sequences are observed in the clusters, we examined the roles of a transcriptional repressor Bcl6 and the regional histone modification in the expression of these chemokine genes in pulmonary epithelium.

METHODS

We generated transgenic (Tg) mice carrying the Bcl6 or the dominant-negative (DN)-Bcl6 gene under the control of the surfactant protein C (SPC) promoter that induces the exogenous gene expression in the distal lung epithelium. For in vitro studies, A549, alveolar type II-like epithelial cell line transfected with the SPC-DN-Bcl6 gene were stimulated with IL-4+TNF-α, and Bcl6 or STAT6 binding to and histone modification of the cluster in the transfectants were analysed by chromatin immunoprecipitation assays. Tg mice sensitized with ovalbumin (OVA) were challenged with OVA inhalation. The amounts of mRNAs in each sample were analysed by quantitative RT-PCR.

RESULTS

The amount of Bcl6 bound to the cluster decreased in A549 cells stimulated with IL-4 and TNF-α, whereas STAT6 binding increased in association with regional histone H3-K9/14 acetylation and H3-K4 methylation. The expression of all chemokine genes in the gene cluster was augmented in activated A549 cells transfected with the DN-Bcl6 gene. We also induced allergic airway inflammation in Tg mice. Expression of the chemokine genes and infiltrated cell numbers in the lungs of these Tg mice with allergic airway inflammation were inversely correlated with the amount of Bcl6 in the lungs.

CONCLUSION AND CLINICAL RELEVANCE

Expression of the pulmonary epithelium-derived CC-type chemokine genes in the cluster is orchestrated by the conserved machinery related to Bcl6. Thus, Bcl6 in pulmonary epithelium may be a critical regulator for pathogenesis of various pulmonary inflammatory diseases.

Clinical characteristics of acute pulmonary thromboembolism in Japan: results of a multicenter registry in the Japanese Society of Pulmonary Embolism Research

BACKGROUND

Although the incidence of acute pulmonary thromboembolism (APTE) has been increasing in Japan, patient characteristics, management strategies, and outcome have not yet been assessed in large series.

HYPOTHESIS

The present study was designed to investigate the current status of APTE in Japan.

METHODS

Of a total of 533 registry patients with pulmonary thromboembolism, 309 with APTE were analyzed with respect to clinical symptoms and signs, predisposing factors, diagnostic procedures, estimation of deep venous thrombosis, treatment, and clinical course.

RESULTS

Main risk factors were recent major surgery, cancer, prolonged immobilization, and obesity; only a few patients had coagulopathy and 36% were in cardiogenic shock at presentation. The majority of registry patients underwent lung scans or pulmonary angiography; 30% were diagnosed only by lung scanning. Venous ultrasonography was used in only 34 patients, while 188 patients underwent at least one diagnostic procedure for deep venous thrombosis. Thrombolysis was more frequently performed in patients with cardiogenic shock, and only a few patients received thromboembolectomy. In-hospital mortality rate was 14%. In patients with cardiogenic shock, the mortality rate was reduced by thrombolysis. The predictors of in-hospital mortality were male gender, cardiogenic shock, cancer, and prolonged immobilization.

CONCLUSIONS

The patients in this registry had almost the same findings as those in Western patients, except for some points that had the possibility of demonstrating a difference between Westerners and Japanese in the development of APTE. These results can prove especially helpful in planning prospective, randomized trials that will clarify the impact of widely used treatment modalities on the outcome of patients with APTE.

Eosinophilia in bronchoalveolar lavage fluid and architectural destruction are features of desquamative interstitial pneumonia

AIMS

Desquamative interstitial pneumonia (DIP) is a rare pattern of diffuse parenchymal lung disease known to overlap with respiratory bronchiolitis-interstitial lung disease (RB-ILD). The aim was to review biopsy-proven cases of DIP to investigate further the clinical, imaging and histological features of this disease.

METHODS AND RESULTS

Twenty patients fulfilled the pathological criteria: 19 men and one woman with a mean age of 54 years. Clinical features, bronchoalveolar lavage (BAL) data, radiological findings, pathological findings other than criteria, effect of therapy and outcome were examined. The BAL data for 17 cases revealed marked eosinophilia (mean 18%) and moderate neutrophilia (mean 11%). Computed tomography in 17 patients showed peripheral involvement in all cases with a clear margin in 64% and thin-walled cysts in 35% of cases. Additional pathological features were a distinct lobular distribution (70%) and architectural destruction (70%) with cyst formation (55%). Eighteen of the 19 patients (95%) improved under steroid pulse and/or oral therapy. Sixteen subjects (80%) are alive, three died of other diseases and one died of DIP 74 months after the diagnosis. Percent vital capacity increased significantly and new thin-walled cysts appeared in one case.

CONCLUSIONS

BAL eosinophilia, lobular distribution and architectural destruction with cyst formation are characteristic features of DIP.

Antifungal susceptibility of Candida species using the Clinical and Laboratory Standards Institute disk diffusion and broth microdilution methods

There are conflicting reports on the agreement between the Clinical and Laboratory Standards Institute disk diffusion (M44-A) and reference broth microdilution (M27-A) methods for determination of antifungal susceptibility of yeasts. The antifungal susceptibility of 541 yeasts, the majority of which were from the oral cavity, was determined using these two methods and the accuracy of the disk diffusion method assessed for clinical testing of various Candida species. Of the strains tested, Candida albicans predominated (390 out of 541). The classification of susceptibility determined by the disk diffusion method was largely in concordance with that obtained using the broth dilution method, regardless of species within Candida genus. The overall observed agreement between these two methods was 94.7% for fluconazole and 96.7% for voriconazole was with a 'very major' discrepancy level of 1.5% and 1.7% respectively. This study demonstrates a strong agreement of the simple disk diffusion method with the more labour intensive 'gold standard' broth microdilution method. These findings would support the use of the disk diffusion method in a routine mycology service.

Antimicrobial susceptibility of 800 anaerobic isolates from patients with dentoalveolar infection to 13 oral antibiotics

INTRODUCTION

The aim of this study was to determine the current antimicrobial susceptibility of the principle anaerobic pathogens involved in dentoalveolar infection, to 13 oral antibiotics, and to assess the value of each antibiotic in the management of the infection.

METHODS

A total of 800 isolates from patients with dentoalveolar infection (Prevotella species, Fusobacterium species, Porphyromonas species and Peptostreptococcus micros) were tested for their susceptibility to amoxicillin, amoxicillin/clavulanate, cefaclor, cefuroxime, cefcapene, cefdinir, erythromycin, azithromycin, telithromycin, minocycline, levofloxacin, clindamycin, and metronidazole using an agar dilution method.

RESULTS

Although the majority of Fusobacterium strains were resistant to erythromycin, azithromycin, and telithromycin, the remaining antibiotics demonstrated a high level of antimicrobial activity. P. micros and Porphyromonas species exhibited high susceptibility to all antibiotics tested in this study. In the case of Prevotella species, resistance to amoxicillin occurred in 34% of isolates and all of these resistant strains were found to produce beta-lactamase. Susceptibility of Prevotella strains to cefaclor, cefuroxime, cefcapene, cefdinir, erythromycin, azithromycin, and minocycline was found to correlate with amoxicillin susceptibility. Amoxicillin/clavulanate, telithromycin, clindamycin, and metronidazole exhibited high antimicrobial activity even against amoxicillin-resistant strains of Prevotella species.

CONCLUSION

Amoxicillin would still be advocated therefore as being a suitable first-line agent, while reduced susceptibility of Prevotella strains remains a matter of concern with penicillins. Amoxicillin/clavulanate, clindamycin, and metronidazole are useful alternatives in combating the anaerobic bacteria involved in dentoalveolar infection.

Mechanism of the ropivacaine-induced increase in intracellular Ca2+ concentration in rat aortic smooth muscle

BACKGROUND

Ropivacaine is a long-acting local anesthetic with low cardiac toxicity that induces vasoconstriction in vitro and in vivo. Vascular smooth muscle tone is regulated by changes in both intracellular Ca(2+) concentration ([Ca(2+)](i)) and myofilament Ca(2+) sensitivity. Therefore, the aim of this study was to examine the mechanism underlying the increase in [Ca(2+)](i) in ropivacaine-induced vascular contraction.

METHODS

Ropivacaine-induced contractile responses and changes in [Ca(2+)](i) were examined using an isometric force transducer and a fluorometer, respectively.

RESULTS

Ropivacaine induced a biphasic, concentration-dependent change in [Ca(2+)](i) and contractile response in rat aortic smooth muscles: an increase in [Ca(2+)](i) occurred at lower ropivacaine concentrations (3 x 10(-5) to 3 x 10(-4) M) and a decrease was observed at higher concentrations (10(-3) to 3 x 10(-3) M). Contraction and the [Ca(2+)](i) increase induced by ropivacaine were attenuated significantly by a voltage-dependent Ca(2+) channel antagonist, an inositol 1,4,5-triphosphate receptor antagonist and Ca(2+)-free solution (P < 0.01, n = 6).

CONCLUSION

Ropivacaine-induced contraction of rat aortic smooth muscle is, in part, regulated by Ca(2+) influx from the extracellular space and Ca(2+) release from the sarcoplasmic reticulum.

Pulmonary toxicity of cytotoxic agents: A meta-analysis

19573

Background: Pulmonary toxicity is one of the most serious adverse effects of cytotoxic agents, and affected patients require discontinuation of the anti-cancer therapy, and it even proves fatal in many cases. Its incidence, however, may be considerably biased, as it may be influenced by many factors such as intercurrent medications or co-morbidities. The purpose of our study was to evaluate the incidences of pulmonary toxicity by cytotoxic agents in published data relating to prospective randomized comparative studies. Methods: A Medline literature search was conducted to extract prospective randomized comparative studies (either phase II or III) that included docetaxel, paclitaxel, irinotecan, vinorelbine and gemcitabine. Comparisons had to be performed between regimens with and without one of these agents, in addition to best supportive care with or without other common agent(s), so as to be able to clearly attribute the toxicity to the agent. Reports lacking detailed toxicity data were excluded. Results: The table below summarizes the results of the finally evaluated 47 studies (5 to 12 per agent) fulfilling the criteria. As many studies showed no pulmonary toxicity, standard statistical methods for meta-analysis were not applicable. Conclusions: The present study analyzing data in prospective randomized comparative studies might minimize bias of the relative incidence of pulmonary toxicity. Pulmonary toxicity was rarely encountered in randomized comparative studies. No increase in frequency was shown by the inclusion of any of the five cytotoxic agents.

[Table: see text]

No significant financial relationships to disclose.

The effects of FasL on inflammation and tumor survival are dependent on its expression levels

The apoptosis-inducing Fas ligand (FasL) is expressed in a variety of human cancers and has been implicated in tumor immune evasion. Paradoxically, ectopic expression of FasL in experimental tumors triggers a neutrophil-mediated inflammatory response and tumor rejection. To resolve these conflicting findings, we have established B16 melanoma and P29 Lewis lung carcinoma lines expressing different levels of FasL and examined their tumorigenicity in vivo. While tumors with a high level of FasL were rapidly rejected as previously reported, those expressing a low level of FasL were not rejected but grew faster than did FasL-negative parental cells. The growth enhancement of FasL(low) tumors was not observed in T-cell-deficient nude mice, suggesting that FasL expressed in tumors at low levels counteracted against T-cell-dependent antitumor responses. In support of this notion, FasL(low) tumors were found to grow faster than parental cells in mice that had acquired tumor-specific immunity. Furthermore, histological examinations revealed apoptosis of lymphocytes in tissue sections of FasL(low) tumors. These results collectively suggest that FasL on tumors is a double-edged sword: at high levels it triggers tumor rejection whereas at low levels it facilitates tumor growth possibly by suppressing antitumor immune responses.

Phase II study of weekly irinotecan and cisplatin for refractory or recurrent non-small cell lung cancer (NSCLC)

17002

Background: A current option for recurrent NSCLC is monotherapy with docetaxel. However, cisplatin, if tolerable, may still have power for this condition. Irinotecan is also a key drug for NSCLC. The objectives of this study were to evaluate the clinical relevance of weekly chemotherapy consisting of irinotecan and cisplatin as a 2nd-line therapy for NSCLC. Methods: Patients meeting all following criteria were eligible: proven NSCLC refractory or recurrent after previous single-regimen chemotherapy, PS (0–2), age > 15 years, adequate organ functions, measurable lesions by RECIST, life expectancy exceeding 8 weeks, and written informed consent. Patients with any of the following conditions were ineligible: previous treatment with irinotecan and/or surgery, requirement of thoracic irradiation, interstitial lung disease, pleural effusion or ascites requiring treatment, pericardial effusion, symptomatic brain metastasis, concomitant malignancy or other inadequate condition. Irinotecan (60 mg/m2 in 500 ml electrolyte soln, day 1) and cisplatin (25 mg/m2 in 500 ml saline, day 1, without further hydration) were administered every week for at least 6 courses unless encountering defined skip criteria. Calculated minimum sample size was 43 based on Simon two-stage optimal design with p0=0.10, p1=0.25, α error=0.05 and β error=0.20; planned sample size was 48. The primary endpoint was response rate, and the secondary ones were toxicity and survival time. Results: Since February 2002, 48 patients (consisting of 29 with adeno-, 14 with squamous cell, 3 with large cell carcinoma and 2 with NSCLC not further specified) with a median age of 62-years were enrolled, with 1 death before treatment. Therefore, 47 patients were eligible for evaluation of response rate and toxicity, whereas all 48 were analyzed for survival. Chemotherapy was administered for a median 6 courses (range, 0–15). Response rate was 25.5% (95% CI: 12.9–38.1%). Toxicity of grade 3 or 4 consisted of neutropenia (29.8%), thrombocytopenia (6.4%), anemia (29.8%), diarrhea (10.6%) and nausea (21.3%). MST was 10.6 months, and 1-year survival rate was 43%. Conclusions: This 2nd-line chemotherapy for NSCLC showed promising efficacy with tolerable toxicity.

No significant financial relationships to disclose.

In vitro susceptibility of oral Candida to seven antifungal agents

The in vitro susceptibility of 618 Candida isolates to fluconazole, itraconazole, voriconazole, ketoconazole, miconazole, amphotericin B, and nystatin was determined. The isolates were obtained from 559 patients who had attended the UK dental hospital departments in Cardiff, Belfast, Glasgow or London. Antifungal susceptibility was assessed using a broth microdilution method following the National Committee for Clinical Laboratory Standards (NCCLS) M27-A guidelines. The majority of the test strains were C. albicans (n = 521) with few of these being resistant to fluconazole (0.3%). A low incidence of fluconazole resistance (0-6.8%) was similarly evident with all non albicans species (Candida glabrata, 5 of 59 resistant; Candida krusei, 0 of 7 resistant; Candida tropicalis, 0 of 13 resistant; Candida parapsilosis, 0 of 12 resistant; other Candida species, 0 of 6 resistant). Voriconazole, ketoconazole, and miconazole also revealed high activity against both C. albicans and non albicans isolates, and 23.7% of C. glabrata isolates were found to be resistant to itraconazole. There was little difference in the antifungal susceptibilities of Candida isolated from patients who had a history of previous antifungal therapy compared with those who had not received antifungal treatment. In summary, this surveillance study of antifungal susceptibility of oral candidal isolates in the UK, through the collaboration of four dental hospitals, demonstrates that oral Candida species have a high level of susceptibilities to a range of antifungal agents.

An outcome audit of the treatment of acute dentoalveolar infection: impact of penicillin resistance

OBJECTIVES

The aim of this audit was to measure the outcome of treatment of acute dentoalveolar infection and to determine if this was influenced by choice of antibiotic therapy or the presence of penicillin-resistance.

SUBJECTS AND METHODS

A total of 112 patients with dentoalveolar infection were included in the audit. All patients underwent drainage, either incisional (n=105) or opening of the pulp chamber (n=7) supplemented with antibiotic therapy. A pus specimen was obtained from each patient for culture and susceptibility. Clinical signs and symptoms were recorded at the time of first presentation and re-evaluated after 48 or 72 h.

RESULTS

A total of 104 (99%) of the patients who underwent incisional drainage exhibited improvement after 72 h. Signs and symptoms also improved in five of the seven patients who underwent drainage by opening of the root canal although the degree of improvement was less than that achieved by incisional drainage. Penicillin-resistant bacteria were found in 42 (38%) of the 112 patients in this study. Of the 65 patients who were given penicillin, 28 had penicillin-resistant bacteria. There was no statistical difference in the clinical outcome with regard to the antibiotic prescribed and the presence of penicillin-resistant bacteria. Strains of penicillin-resistant bacteria were isolated more frequently in patients who had previously received penicillin (p<0.05).

CONCLUSION

Incisional drainage appeared to produce a more rapid improvement compared to drainage by opening of the root canal. The presence of penicillin-resistant bacteria did not adversely affect the outcome of treatment. The observations made support surgical drainage as the first principle of management and question the value of prescribing penicillin as part of treatment.

Experimental Study on the Morphological and Functional Recovery following Partial Glossectomy in Rabbits: A Comparison between CO2Laser and Electrocautery

OBJECTIVE

The aim of the present study was to evaluate and compare the morphological and functional recovery following partial glossectomy in rabbits with the CO(2) laser and electrocautery.

METHODS

Partial glossectomy with the CO(2) laser or electrocautery in rabbits was performed to investigate changes in the body weight and tongue width after surgery. The study models were classified into three groups. In group 1, the excised edges of the wound were left unsutured after partial glossectomy with the CO(2) laser. In group 2, the wound was closed after CO(2) laser surgery. In group 3, as a control group, the wound was closed after partial glossectomy with electrocautery. The specimens of the tongues obtained from the rabbit were microscopically assessed.

RESULTS

No significant differences were found in the percent change in the body weight among the three groups. There was a significant difference in the tongue width between groups 1 and 3 at each time point: 2 weeks (p < 0.05), 4 weeks (p < 0.01), and 8 weeks (p < 0.001) postoperatively. Furthermore, there was a significant difference in the tongue width between groups 2 and 3 at 8 weeks (p < 0.02) postoperatively. Histologically, the scar tissue of the wound was extensive in the control group, although it was localized in the laser group.

CONCLUSION

Postoperative dysfunction was reduced when excised edges were left unsutured after partial glossectomy with the CO(2) laser.

Association of clinical features with HLA in chronic pulmonary thromboembolism

The aetiology of chronic thromboembolic pulmonary hypertension (CTEPH) is largely unknown and may be heterogeneous, because there are several ethnic differences in the clinical characteristics of CTEPH. Female predominance and a higher ratio of chronic to acute pulmonary thromboembolism have been reported in Japan as compared with the USA. Because such ethnic differences may be controlled by genetic factors, the current study investigated HLA polymorphisms in Japanese patients with CTEPH. HLA typing by serological and/or DNA typing methods was performed (for HLA-A, B, DPB1, DRB1) in 80 patients and 678 controls, and the association of clinical characteristics with HLA alleles was studied. The frequencies of HLA-B*5201 (40 versus 24%) and DPB1*0202 (19 versus 6%) were significantly higher in the patients. HLA-B*5201 positive patients showed a significant female predominance. Total pulmonary vascular resistance and mixed venous oxygen tension were better in the HLA-B*5201 positive patients. In contrast, cardiac index and gas exchange parameters were worse in the HLA-DPB1*0202 positive patients. In the patients carrying HLA-B*5201 and/or -DPB1*0202, the frequency of deep vein thrombosis was significantly lower than the other patients. These observations suggested that both the susceptibility and clinical characteristics of chronic thromboembolic pulmonary hypertension were controlled in part by the HLA-B and -DPB1 loci.

Expression of interleukin-22 in murine carcinoma cells did not influence tumour growth in vivo but did improve survival of the inoculated hosts

Interleukin (IL)-22, a novel cytokine belonging to the IL-10 family, is secreted from activated T and natural killer cells and is possibly involved in inflammatory responses. We examined whether expression of the IL-22 gene in murine colon carcinoma Colon 26 cells (Colon 26/IL-22) could produce any antitumour effects in the inoculated mice. Although growth of Colon 26/IL-22 tumours in syngeneic mice was not different from that of parent tumours, survival of the mice that were subcutaneously or intraperitoneally inoculated with Colon 26/IL-22 tumours was significantly prolonged compared with the mice inoculated with parent tumours. Metastasis was not influenced by IL-22 expressed in tumours. Expression of the IL-22 receptor-specific gene, IL-22R, was not induced in spleen cells stimulated with concanavalin A, anti-CD3 or anti-CD40 antibody, despite constitutive expression of the IL-10R2 gene, which encodes another component of the heterodimeric IL-22 receptor complex. IL-22 thereby does not directly act on immunocompetent cells, and IL-22 expressed in tumours can favour apothanasia of inoculated hosts.

The microbial synergy of Peptostreptococcus micros and Prevotella intermedia in a murine abscess model

This study characterized the microbial interaction of Peptostreptococcus micros and Prevotella intermedia, the major pathogens of dentoalveolar infection, using a murine model. Subcutaneous injection of P. micros cells in the dorsum of the mouse together with living cells of P. intermedia resulted in a significantly larger abscess when compared with single injection of the organisms (P < 0.02). The abscess size was also significantly increased (P < 0.05) when the plate-cultured cell suspension of P. micros was injected into mouse with the culture filtrate of P. intermedia. The heat-treated culture filtrate of P. intermedia also enhanced the virulence of P. micros. P. micros culture filtrate did not affect the virulence of P. intermedia. Interestingly, the virulence of P. micros appeared to be enhanced even when the culture filtrate of P. intermedia was injected at separate sites in the mouse. These results suggest that a heat-stable product or products of P. intermedia increase the virulence of P. micros indirectly by altering the host condition, whereas living cells of P. micros can directly enhance virulence of P. intermedia.

In vitro secreted aspartyl proteinase activity of Candida albicans isolated from oral diseases and healthy oral cavities

The in vitro secreted aspartyl proteinase (SAP) activity of Candida albicans isolated from a variety of oral conditions, including healthy oral cavities, was determined. SAP activity (units/10(6) cells/ml, +/-SD) was 0.28 +/- 0.33 for pseudomembranous candidosis isolates (n = 18), 0.35 +/- 0.46 for chronic erythematous candidosis isolates (n = 21) and 0.30 +/- 0.32 for chronic hyperplastic candidosis isolates (n = 50). SAP activity of 0.19 +/- 0.22 was recorded for isolates from squamous cell carcinoma (n = 18), 0.26 +/- 0.37 for burning mouth syndrome isolates (n = 29), 0.25 +/- 0.38 for isolates from xerostomia (n = 15) and 0.39 +/- 0.50 for isolates from lichen planus (n = 13). The SAP activity of isolates from oral disease states was significantly (P < 0.05) higher than that recorded for 28 isolates from healthy mouths (activity of 0.04 +/- 0.03). However, there was no significant difference in the SAP activity between the three forms of clinical oral candidosis (P > 0.05). SAP activity was inhibited in control samples containing the SAP inhibitor, pepstatin A. These results indicate that C. albicans strains associated with oral disease have inherently higher SAP activity.

Feasibility of combination chemotherapy with cisplatin and etoposide for haemodialysis patients with lung cancer

Cancer chemotherapy for haemodialysis patients has never been established. To elucidate the feasibility of cisplatin-based combination chemotherapy for haemodialysis patients with lung cancer, a dose escalation study was conducted. Five haemodialysis patients with lung cancer were treated with cisplatin and etoposide. A starting dose of 40 mg m(-2) of cisplatin on day 1 and 50 mg m(-2) of etoposide on days 1, 3 and 5 were administered as the first course for the first patient. Membrane haemodialysis was regularly performed three times a week and soon after the completion of therapy. By monitoring toxicity and pharmacokinetics data, the dose was escalated course by course and patient by patient. Dose escalation was completed for the first two patients resulting in full-dose chemotherapy consisting of 80 mg m(-2) of cisplatin on day 1 and 100 mg m(-2) of etoposide on days 1, 3 and 5. Multiple courses of the full-dose chemotherapy were administered to the other three patients. Toxicity was manageable and tolerable for all. Pharmacokinetics data were comparable to those from patients with normal renal function, except for potential long-lasting higher levels of free platinum in the renal insufficiency group. In conclusion, this standard-dose combination chemotherapy was feasible even for haemodialysis patients.

Antimicrobial susceptibility of major pathogens of orofacial odontogenic infections to 11 beta-lactam antibiotics

In this study, we evaluated the current effectiveness of 11 beta-lactam antibiotics for treatment of orofacial odontogenic infections by determining the antimicrobial susceptibility of the major pathogens. The antimicrobial susceptibilities of viridans streptococci (n = 47), Peptostreptococcus (n = 67), Porphyromonas (n = 18), Fusobacterium (n = 57), black-pigmented Prevotella (n = 59) and non-pigmented Prevotella (n = 47) isolated from pus specimens of 93 orofacial odontogenic infections to penicillin G, cefmetazole, flomoxef, cefoperazone, cefoperazone/sulbactam, ceftazidime, cefpirome, cefepime, cefoselis, imipenem and faropenem were determined using the agar dilution method. Penicillin G, most cephalosporins, imipenem and faropenem worked well against viridans streptococci, Peptostreptococcus, Porphyromonas and Fusobacterium. Penicillin G and most cephalosporins, including fourth-generation agents, were not effective against beta-lactamase-positive Prevotella, though they were effective against beta-lactamase-negative strains. Cefmetazole, cefoperazone/sulbactam, imipenem and faropenem expressed powerful antimicrobial activity against beta-lactamase-positive Prevotella. In conclusion, penicillins have the potential to be first-line agents in the treatment of orofacial odontogenic infections. Most of the other beta-lactam antibiotics, including fourth-generation cephalosporins, were not found to have greater effectiveness than penicillins. In contrast, cefmetazole, cefoperazone/sulbactam, imipenem and faropenem were found to have greater effectiveness than penicillins.

Activation of pulmonary T cells in corticosteroid-resistant and -sensitive interstitial pneumonitis in dermatomyositis/polymyositis

To study the activation states and cytokine profiles of pulmonary T cells in corticosteroid-resistant and corticosteroid-sensitive interstitial pneumonitis (IP) in dermatomyositis (DM)/polymyositis (PM), we examined the activation markers and cytokine profiles of T cells in bronchoalveolar lavage fluids (BALF) from patients with IP in DM/PM before prednisolone therapy and then compared the activation states of T cells according to the therapeutic response of IP to prednisolone therapy. CD25+ CD4+ T cells in BALF were significantly increased in both corticosteroid-resistant and corticosteroid-sensitive IP in DM/PM as compared with those in controls without IP. Furthermore, CD25+ CD4+ T cells in BALF were significantly more increased in corticosteroid-resistant IP than those in cortico teroid- sensitive IP. Moreover, CD25+ CD8+ T cells in BALF were significantly increased only in corticosteroid-resistant IP, but not in corticosteroid-sensitive IP or controls without IP. IFN-gamma mRNA was detected in BALF T cells in corticosteroid-resistant and corticosteroid-sensitive IP but not in controls without IP, whereas IL-4 mRNA was virtually undetected in BALF T cells in both the IP groups. However, there were no significant differences in CD4/CD8 ratio of BALF T cells, HLA-DR+ BALF T cells or CD25+ and HLA-DR+ peripheral blood T cells between the two IP groups. These results indicate that activated Th1-type pulmonary T cells play an important role in the development of corticosteroid- resistant IP in DM/PM and that the increase in CD25+ CD8+ T cells in BALF is a useful indicator for corticosteroid-resistant IP in DM/PM and hence may be an indicator for early use of cyclosporin.

Effects of insulin-like growth factor on nitrogen balance during hypoxic exposure

Acute exacerbations of chronic obstructive pulmonary disease (COPD) accompanied with hypoxaemia may induce net protein catabolism and hypoxaemia could be an important trigger of a systemic catabolic response. The aim of this study was to examine the anabolic effects of recombinant human insulin-like growth factor-I (IGF-1) in rats exposed to hypoxia. Although acute hypoxia is usually accompanied with a decrease in dietary intake, the usual nitrogen intake was maintained in this study. Sprague-Dawley rats were maintained by continuous infusion of solution for total parenteral nutrition for 6 days. The animals were then randomly assigned to a normoxic (N) or a hypoxic (H) group. During the last 3 days of the experiment N and H rats were randomised to receive either IGF-I or vehicle. Exposure to hypoxia caused a decrease in body-weight gain accompanied by a negative nitrogen balance, which was mainly due to increased urinary nitrogen excretion. No effect of recombinant human IGF-I treatment on body weight was observed during exposure to hypoxia, although nitrogen balance normalised. The co-infusion of recombinant human insulin-like growth factor-1 and total parenteral nutrition has a significant net anabolic effect, as demonstrated by nitrogen retention and reduction in urine protein excretion observed in rats. Insulin-like growth factor-1 may help to ameliorate the protein catabolism observed under hypoxic conditions.

Bacteriology and antimicrobial susceptibility of gram-positive cocci isolated from pus specimens of orofacial odontogenic infections

We recently reported the beta-lactamase production and antimicrobial susceptibility of anaerobic gram-negative rods isolated from pus specimens of 93 orofacial odontogenic infections. In this report, we determine the bacteriology and antimicrobial susceptibility of bacteria other than anaerobic gram-negative rods, mainly gram-positive cocci, isolated from the same specimens. Streptococcus constellatus and Peptostreptococcus micros were frequent isolates from all types of infection examined. Peptostreptococcus prevotii, Corynebacterium species, and Eubacterium species were recovered only from dentoalveolar infections, while Gemella morbillorum was found more frequently in periodontitis than in the other infections. beta-Lactamase-positive strains were detected only in staphylococci. Ampicillin, ampicillin/sulbactam, cefazolin, cefotaxime, imipenem, erythromycin, clindamycin and levofloxacin showed high susceptibility rates (> or = 77%) against viridans streptococci, Peptostreptococcus and Gemella. Minocycline showed a high MIC90 value against viridans streptococci (32 microg/ml), and metronidazole was effective against Peptostreptococcus and Gemella. These results provide useful information for the treatment of orofacial odontogenic infections.

Ehlers-Danlos syndrome type IV with few extrathoracic findings: a newly recognized point mutation in the COL3A1 gene

Ehlers-Danlos syndrome type IV (EDS IV) is caused by mutation within the COL3AI gene, resulting in the disorder of type III procollagen. The diagnosis is confirmed by demonstrating the synthesis of abnormal type III procollagen molecules from cultured dermal fibroblasts or by identifying the mutation in the COL3A1 gene. The authors report a case of EDS IV caused by a novel point mutation in the COL3A1 gene in a 16-yr-old female. Recurrent haemoptysis and cavitary formation of the lung were evidence of pulmonary involvement. However, extrathoracic manifestations of EDS IV were mostly absent. To the best of the authors' knowledge, all previously reported Ehlers-Danlos syndrome IV patients with respiratory disease had the characteristic findings or histories of Ehlers-Danlos syndrome IV. In the present case, connective tissue friability was suspected due to tissue laceration observed in the biopsied lung specimen, and the diagnosis was made beginning from this pivotal finding.

Stable pulmonary capillary haemangiomatosis without symptomatic pulmonary hypertension

Pulmonary capillary haemangiomatosis is a rare disorder characterised by multiple angiomatous lesions composed of proliferating capillary vessels in the lung parenchyma that usually progress rapidly to establish fatal pulmonary hypertension. The 29 year old man presented here, however, has been stable for 3.5 years since the diagnosis without symptoms of pulmonary hypertension. High resolution computed tomographic findings of the pulmonary lesions seemed specific to the disease.

Clinico-epidemiological features of pulmonary histiocytosis X

OBJECTIVE

To define the clinico-epidemiological features of pulmonary histiocytosis X in Japan.

METHODS

A nationwide survey was carried out in 1997 using two questionnaires.

RESULTS

The first questionnaire, which attempted to determine the number of patients during 1996, revealed that the number of patients treated at hospitals with 200 or more beds during the one-year period was estimated to be 160 (95% confidence interval: 140-180). The estimated crude prevalence among those aged 16 to 70 years was calculated as 0.27 and 0.07 per 100,000 population in males and females, respectively. The second questionnaire was concerned with the clinico-epidemiological features of the disease. Seventy-three histologically diagnosed patients were evaluated. It primarily afflicted younger adults, between the ages of 20 and 50, and showed a male predominance. Over 90% of the patients were smokers or ex-smokers and over 50% started smoking before 20 years of age, suggesting a strong association with cigarette smoking. Steroid therapy was applicable to 34% of the patients. In the patients who received steroid therapy, regression and stabilization were observed in 28% and deterioration in 36%. As for the patients for whom steroids were not required, remission occurred in 63% and progression in 10%. The ratio of remissions plus stabilization was higher in the patients who were not treated with steroids compared with those who required steroid therapy (p<0.05).

CONCLUSION

In patients with pulmonary histiocytosis X therapeutic results obtained with steroids seemed not to be encouraging, although steroids are thought to be the most plausible treatment.

Measurement of heat conduction through stacked screens

This paper describes the experimental apparatus for the measurement of heat conduction through stacked screens as well as some experimental results taken with the apparatus. Screens are stacked in a fiberglass-epoxy cylinder, which is 24.4 mm in diameter and 55 mm in length. The cold end of the stacked screens is cooled by a Gifford-McMahon (GM) cryocooler at cryogenic temperature, and the hot end is maintained at room temperature. Heat conduction through the screens is determined from the temperature gradient in a calibrated heat flow sensor mounted between the cold end of the stacked screens and the GM cryocooler. The samples used for these experiments consisted of 400-mesh stainless steel screens, 400-mesh phosphor bronze screens, and two different porosities of 325-mesh stainless steel screens. The wire diameter of the 400-mesh stainless steel and phosphor bronze screens was 25.4 micrometers and the 325-mesh stainless steel screen wire diameters were 22.9 micrometers and 27.9 micrometers. Standard porosity values were used for the experimental data with additional porosity values used on selected experiments. The experimental results showed that the helium gas between each screen enhanced the heat conduction through the stacked screens by several orders of magnitude compared to that in vacuum. The conduction degradation factor is the ratio of actual heat conduction to the heat conduction where the regenerator material is assumed to be a solid rod of the same cross sectional area as the metal fraction of the screen. This factor was about 0.1 for the stainless steel and 0.022 for the phosphor bronze, and almost constant for the temperature range of 40 to 80 K at the cold end.

Effects of regenerator geometry on pulse tube refrigerator performance

This paper gives results of the cooling performance of a double-inlet pulse tube refrigerator using various regenerators. The same pulse tube was used for all the experiments and measured 4.76 mm in diameter and 46.2 mm in length. A commercial linear compressor with a swept volume of 4 cm3 was used in these experiments. The operating conditions were held constant at a mean pressure of 2.0 MPa and a frequency of 54 Hz. Using finite difference software called REGEN3.1, developed at NIST, and recent experiment results, we optimized a series of regenerators based on dimensions, materials and screen packing. The values used for calculating the thermal conduction through stacked screens by REGEN3.1 were based on recent experimental results from NIST. The regenerator tubes were designed using 316 stainless steel and titanium materials. The regenerator matrices investigated were 400-mesh and 500-mesh stainless steel screen. The valve settings for both orifices were adjusted to minimize the no-load temperature for all regenerators. A cooling capacity curve from 0 to 3 W was also determined. The performance of the pulse tube refrigerator using the different regenerators is discussed. The experimental results from the various regenerators are evaluated and compared with their corresponding numerically calculated coefficient of performance (COP) and regenerator design as determined by REGEN3.1.

Plasma monocyte chemoattractant protein-1 and pulmonary vascular resistance in chronic thromboembolic pulmonary hypertension

The pathogenesis of severe pulmonary hypertension seems to be related to inflammatory response in diseased sites. Monocyte chemoattractant protein-1 (MCP-1) has been reported to play a role in the development of congestive heart failure. In this immunological response, activation and migration of leukocytes including macrophages to the inflammatory region are important factors. We hypothesized that the severity of pulmonary hypertension may be related to MCP-1, which is thought to be upregulated by blood pressure or shear stress in pulmonary vasculature as well as by immunological and inflammatory reactions in chronic thromboembolic pulmonary hypertension (CTEPH). Circulating levels of MCP-1, interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha) were measured by sandwich ELISA in 14 patients with CTEPH. The plasma level of MCP-1 was significantly correlated with pulmonary vascular resistance. In IL-1beta and TNF-alpha, on the other hand, there was no correlation between cytokines and pulmonary hemodynamics. Pathological specimens obtained from the patients with CTEPH undergoing thromboendarterectomy demonstrated immunoreactivity of MCP-1 in endothelium, smooth muscle cells, and macrophages within neointima in the hypertensive large elastic pulmonary artery. We conclude that MCP-1 is upregulated in the remodeling of pulmonary arteries in close association with increased pulmonary vascular resistance in CTEPH.

Optimal combination of seven tumour markers in prediction of advanced stage at first examination of patients with non-small cell lung cancer

Between Januaty 1996 and December 1999, we examined seven tumour markers (carcinoembryonic antigen (CEA), alpha feto protein (AFP), cancer antigen CAI9-9 (CA199), squamous cell carcinoma antigen (SCC), neuron-specific enolase (NSE), cancer antigen CA125 (CA125), cytokeratin 19 fragment (CYFRA)) in 312 patients (200 patients with adenocarcinoma (Ad); 112 patients with squamous cell carcinoma (Sq)). In Ad patients, CEA showed the highest positivity rate (46.5% of Ad patients) which rose as the stage advanced and was followed by CA125, the positivity rate of which also increased with the stage. All the Ad cases (35 out of 35:100%) with CA125 levels above 70 ng/ml were advanced (stage IIIB or IV), regardless of the other tumour markers. In Sq patients, the positivity rate of CYFRA (48.2%) was the second highest behind SCC (55.4%), but increased as the stage advanced. As regards the combinations of two markers, in Ad patients, both CYFRA and CA 125 showed significant supplementary value when used with CEA, even though CEA expression was absent. Furthermore, most ofthe CEA, CYFRA (25 out of 26:96.2%) and CEA, CA125 (38 out of 40:95.0%) double-positive Ad patients were also in the advanced stage. In Sq patients, no additional sensitivity and specificity in the prediction of advanced stage resulted from any combination of CYFRA with other markers. By selecting appropriate tumour markers in NSCLC patients, we can predict the stage of the lung cancer and utilize these markers as complementaty tools to establish indications for treatment.

Effects of hemoglobin on pulmonary arterial pressure and pulmonary vascular resistance in patients with chronic emphysema

BACKGROUND

The increase in viscosity caused by secondary polycythemia is thought to be one of the major causes of pulmonary hypertension secondary to chronic emphysema. However, very few clinical studies considered the relation between pulmonary hypertension and polycythemia in the case of chronic obstructive pulmonary disease.

OBJECTIVE

The purpose of this study is to elucidate the relative contribution of an increase in hemoglobin level (Hb) to mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR).

METHODS

We retrospectively investigated 41 patients with chronic emphysema who had undergone a right heart catheterization. Multiple-regression analysis and F test were performed to investigate both direct effects of Hb and PaO(2) as independent variables on mPAP and PVR as dependent variables.

RESULTS

Significant correlations were found between PaO(2) and mPAP (or PVR), or Hb and mPAP (or PVR), indicating that both Hb and PaO(2) are contributory to mPAP and PVR. The F test demonstrated that Hb and PaO(2) could directly affect the level of either mPAP or PVR.

CONCLUSIONS

It was concluded that Hb had a direct effect on mPAP and PVR, independently of hypoxia in patients with chronic emphysema.

Effect of levofloxacin on theophylline clearance during theophylline and clarithromycin combination therapy

OBJECTIVE

To report a case of decreased theophylline clearance by the addition of levofloxacin in a patient receiving theophylline and clarithromycin.

CASE SUMMARY

A 59-year-old Japanese man who was receiving theophylline for emphysema experienced stimulation, insomnia, and tachycardia due to theophylline toxicity after clarithromycin and levofloxacin were added to the regimen. The combination of these agents resulted in a decrease in theophylline clearance to approximately 60% of the initial value obtained while the patient was receiving theophylline alone. The adverse effects disappeared after the dosage was reduced and the theophylline serum concentration decreased; however, there was no change in theophylline clearance. After discontinuation of levofloxacin, the theophylline serum concentration decreased, and theophylline clearance returned to the initial level even though clarithromycin was continued.

DISCUSSION

Levofloxacin is believed not to influence the clearance of theophylline, although some new fluoroquinolones have been reported to do so. This case indicates that levofloxacin and clarithromycin inhibited theophylline metabolic pathways catalyzed by both CYP1A2 and CYP3A4 and resulted in the decrease in theophylline clearance. The clearance of theophylline, therefore, is not influenced by clarithromycin alone.

CONCLUSIONS

Careful monitoring is required when levofloxacin is prescribed for patients who are taking clarithromycin with theophylline.

[Epidemiology of primary pulmonary hypertension in Japan]

Primary pulmonary hypertension(PPH) is a progressive disease of unknown etiology with poor prognosis. Recent epidemiological studies in Japan have shown that there are 230 patients (95% confidence interval: 200-260) with mean age of 41.8 +/- 18.5 years old, female to male ratio of 1.72: 1 and their median survival time was 69.0 months. At a later time, the clinically effective modalities such as lung transplantation and prostaglandin I2 for PPH were available in Japan. In 1999, the Ministry of Health and Welfare of Japan approved PPH as a objective disease of therapeutic study. Once patient is approved as PPH based on the personal clinical inquiry, Doctor's fee will be paid at the public government. This system will promote earlier and more accurate diagnosis in PPH patients and will clarify more reliable clinico-epidemiological figure of PPH in a whole territory of Japan.

Normal ventilation and ventilatory responses to chemical stimuli in juvenile mutant mice deficient in endothelin-3

Congenital central hypoventilation syndrome (CCHS) and Hirschsprung's disease (HSCR) are often classified as neurocristopathies and are thought to share a common molecular pathogenesis related to the genes that control the development of neural crest cells. We examined whether endothelin-3 (ET-3), one of the developmental regulators of neural crest cells and of which null mutation results in aganglionic megacolon in mice, fulfills the requirements for such a common molecule. To investigate the possible involvement of ET-3 in central ventilatory control, we measured ventilation in mutant mice deficient in ET-3 by whole body plethysmography. Tidal volume and breathing frequency were measured during breathing of room air, hypoxic, hyperoxic, or hypercapnic gas mixtures in awake and anesthetized mice. There were no significant differences in resting ventilation as well as ventilatory responses to hypoxia and hypercapnia between ET-3-knockout mice and wild-type mice. Our results indicate that ET-3 can not be considered as a common pathogenic mechanism for CCHS and HSCR at least in mice.

The role of presenilin 1 during somite segmentation

The Notch signalling pathway plays essential roles during the specification of the rostral and caudal somite halves and subsequent segmentation of the paraxial mesoderm. We have re-investigated the role of presenilin 1 (Ps1; encoded by Psen1) during segmentation using newly generated alleles of the Psen1 mutation. In Psen1-deficient mice, proteolytic activation of Notch1 was significantly affected and the expression of several genes involved in the Notch signalling pathway was altered, including Δ-like3, Hes5, lunatic fringe (Lfng) and Mesp2. Thus, Ps1-dependent activation of the Notch pathway is essential for caudal half somite development. We observed defects in Notch signalling in both the caudal and rostral region of the presomitic mesoderm. In the caudal presomitic mesoderm, Ps1 was involved in maintaining the amplitude of cyclic activation of the Notch pathway, as represented by significant reduction of Lfng expression in Psen1-deficient mice. In the rostral presomitic mesoderm, rapid downregulation of the Mesp2 expression in the presumptive caudal half somite depends on Ps1 and is a prerequisite for caudal somite half specification. Chimaera analysis between Psen1-deficient and wild-type cells revealed that condensation of the wild-type cells in the caudal half somite was concordant with the formation of segment boundaries, while mutant and wild-type cells intermingled in the presomitic mesoderm. This implies that periodic activation of the Notch pathway in the presomitic mesoderm is still latent to segregate the presumptive rostral and caudal somite. A transient episode of Mesp2 expression might be needed for Notch activation by Ps1 to confer rostral or caudal properties. In summary, we propose that Ps1 is involved in the functional manifestation of the segmentation clock in the presomitic mesoderm.

The influence of fractional pulse pressure on the outcome of pulmonary thromboendarterectomy

Although pulmonary thromboendarterectomy is an effective modality for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH), the mortality in patients with severe haemodynamic disease is still high. Recently it was reported that fractional pulse pressure (pulmonary arterial pulse pressure/mean pulmonary arterial pressure) was higher in CTEPH than in primary pulmonary hypertension (PPH). It was hypothesized that fractional pulse pressure might be low in CTEPH with inaccessible distal thrombi and/or secondary pulmonary hypertensive change, resulting to the high operative mortality. To determine the influence of fractional pulse pressure to the outcome of surgery, 32 patients with CTEPH who had thromboendarterectomy between 1985 and 1998 were studied. Pulmonary haemodynamics and fractional pulse pressure were compared between survivors (n=26) and nonsurvivors (n=6) postoperatively. Those parameters in PPH (n=18) and large vessel pulmonary arteritis (n=6) were also analysed. Fractional pulse pressure in CTEPH (1.23+/-0.21) was significantly higher than in PPH (0.93+/-0.22; p=0.0017) and lower than in pulmonary arteritis (1.69+/-0.32; p=0.03). Fractional pulse pressure in survivors (1.26+/-0.21) was significantly higher than in nonsurvivors (1.06+/-0.16; p=0.03). Fractional pulse pressure is a significant predictor for mortality in patients with high pulmonary vascular resistance >1100 dynes.sec.cm(-5). To conclude fractional pulse pressure in addition to pulmonary vascular resistance might be useful in predicting for the outcome of surgery, especially in patients with severe haemodynamic impairment.

Effects of inhaled prostacyclin analogue on chronic hypoxic pulmonary hypertension

Inhaled PGI2 has been reported to elicit pulmonary vasodilation, but whether it is also effective in treating chronic hypoxic pulmonary hypertension is still uncertain. We designed this study to address the in vivo effectiveness of inhaled Beraprost, a stable PGI2 analogue, on pulmonary vascular tone during hypoxic exposure in normoxic (N) and chronically hypoxic (CH) rats. Pulmonary vasodilation was observed by low-dose inhaled Beraprost in N rats, but not in CH rats. It was not until higher doses of Beraprost were given that pulmonary vasodilation was obtained in CH rats. When the agent was continuously administered by an intravascular route at the inhaled dose, it elicited no vasodilation in N rats. On the contrary, it elicited profound vasodilation in CH rats, although a concomitant systemic hypotension was observed. The PGI2 receptor mRNA expression was unchanged in the lungs of CH rats compared with that of N rats. We conclude that low doses of aerosolized Beraprost may reduce pulmonary vascular tone in rats without preexisting lung diseases. In contrast, when hypoxic pulmonary hypertension is present, the threshold of Beraprost inhalation was elevated to provoke pulmonary vasodilation.

Incidence of beta-lactamase production and antimicrobial susceptibility of anaerobic gram-negative rods isolated from pus specimens of orofacial odontogenic infections

The incidence of beta-lactamase production in anaerobic gram-negative rods isolated from 93 pus specimens of orofacial odontogenic infections and the antimicrobial susceptibility of these isolates against 11 antibiotics were determined. A total of 191 anaerobic gram-negative rods were isolated from the specimens. Beta-lactamase was detected in 35.6% of the black-pigmented Prevotella and 31.9% of the nonpigmented Prevotella. However, no strains among the other species isolated produced beta-lactamase. Ampicillin, cefazolin and cefotaxime showed decreased activity as regards beta-lactamase-positive Prevotella strains, whereas the activity of ampicillin/sulbactam, cefmetazole, and imipenem continued to be effective against such strains. All tested beta-lactam antibiotics were effective against Porphyromonas and Fusobacterium. Erythromycin showed decreased activity against nonpigmented Prevotella and Fusobacterium. Clindamycin, minocycline and metronidazole were powerful antibiotics against which anaerobic gram-negative rods could be tested. The present study showed that beta-lactamase-positive strains were found more frequently in the Prevotella strains than in any of the other species of anaerobic gram-negative rods. The effectiveness of adding sulbactam to ampicillin was demonstrated, as well as the difference in cephalosporin activity against beta-lactamase-positive strains.

Blockade of secondary lymphoid tissue chemokine exacerbates Propionibacterium acnes-induced acute lung inflammation

Chemokine-chemokine receptor interaction plays an essential role in leukocyte/dendritic cell (DC) trafficking in inflammation and immune responses. We investigated the pathophysiological roles of secondary lymphoid tissue chemokine (SLC; CCL21) and macrophage inflammatory protein-2 (MIP-2) in the development of acute pulmonary inflammation induced by an intratracheal injection of Propionibacterium acnes in mice. Immunohistochemical studies revealed that SLC was constitutively expressed in the peribronchial areas and perivascular lymphatics in normal mice. MIP-2-positive cells were observed in alveolar spaces in mice challenged with P. acnes. Both neutralization Abs against MIP-2 and CXC chemokine receptor 2 alleviated the P. acnes-induced pulmonary inflammation when injected before P. acnes Ag challenge. On the other hand, polyclonal anti-SLC Abs (pAbs) exacerbated the pulmonary inflammation. The numbers of mature DCs (MHC class II +, CD11c+, and CD86+) as well as macrophages and neutrophils in the P. acnes Ag-challenged lungs were increased, whereas the number of CD4+ T cells, including memory T cells, was decreased. The numbers of mature and proliferating CD4+ T cells (bromodeoxyuridine(+)CD4+) in regional lymph nodes were decreased in mice injected with anti-SLC pAbs compared with those in mice treated with control Abs. An in vitro proliferation assay confirmed the impairment of the Ag-specific T cell response in regional lymph nodes of mice treated with anti-SLC pAbs. These results indicate for the first time a regulatory role for SLC-recruited mature DCs in bridging an acute inflammatory response (innate immunity) and acquired immunity in the lung.