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.