Factors affecting cryopreservation-associated damages in sperm motility of cockerels (Gallus gallus domesticus)

1. Sperm are exposed to severe osmotic stress during cryopreservation, which results in impairment of fertilisation ability, including motility and viability, in poultry. Sperm osmotolerance is regulated by many extracellular factors and varies widely in birds, leading to uncertainty in the nature of the osmotic injury.2. Tail bending is a primary response resulting from cell swelling from excessive osmotic stress. However, the underlying mechanism responsible for tail bending is largely unknown. This study examined the relationship between osmotic stress and post-thaw motility, with a particular focus on the role of Na⁺/K⁺ ATPase (NKA) in the tail bending response.3. Cryopreserved sperm exhibited rapidly reduced motility when maintained at 37°C. The combination of temperature change and osmotic stress was a primary factor responsible for tail bending. This work tested a hypothesis known to be associated with post-thaw tail abnormality in other species and found that cold shock, that is not accompanied by an apoptotic response, may occur. Ouabain inhibition of Na⁺/K⁺ ATPase activity alleviated the tail bending response in fresh and post-thaw sperm.4. These results demonstrated that the combination of temperature change and osmotic stress has a primary impact on the reduction of post-thaw motility, with a particular role in NKA activity, in the tail bending response of chicken sperm. These results provide a foundation for establishing cryopreservation methodology to ensure the optimal fertilisation potential of cryopreserved chicken sperm.

Renin-angiotensin system and cancer: epidemiology, cell signaling, genetics and epigenetics

Day by day, the health and economical burden of cancer increases globally. Indeed it can be considered that there is ''cancer pandemic''. Blocking the renin-angiotensin system (RAS) by angiotensin-converting enzyme (ACE) inhibitors (ACEI) or angiotensin-receptor blockers (ARB) are widely used measures to treat hypertension and heart failure. It has been recently suggested the activation and blocking of RAS has been associated with various types of cancer in epidemiological and experimental studies. Various studies have shown that RAS blockage is protective in some cancers. However, although fewer, contradictory data also showed that RAS blockage is either not related or adversely related to cancer. Although the reasons for these findings are not exactly known, different types of receptors and effectors in RAS may account for these findings. In the current review, we summarize the different RAS receptors and cancer development with regard to epidemiology, and pathogenesis including cell signaling pathways, apoptosis, genetic and epigenetic factors.

P5463Hyperfiltration could be a risk factor for development of hypertension: A five-year cohort study

Background

Some recent studies showed that hyperfiltration is a risk for cardiovascular disease. However, the mechanism is still unknown. This longitudinal study tested the hypothesis that hyperfiltration could be a risk for hypertension.

Methods

This study retrospectively included Japanese healthy adults between 30 and 85 years of age who had medical check-up at our Center for Preventive Medicine, both at enrollment (2004) and at 5-year follow-up (2009). We excluded the subjects with hypertension, diabetes mellitus, dyslipidemia, hyperuricemia, or chronic kidney disease (estimated glomerular filtration <60 mL/min/1.73 m2) at the baseline. We divided this study subjects into three categories of eGFR (60–80 (reference), 80–100, and 100≤mL/min/1.73 m2), and defined hyperfiltration as more than 100 mL/min/1.73 m2 of eGFR. We used logistic regression analyses to examine risk factors for development of hypertension with multiple adjustments for age, sex, smoking, drinking habits, body mass index, and eGFR categories.

Results

In this study, 6045 subjects without comorbidities (mean age of 47±10 years, 1,842 men) were followed for 5 years. Of those, 450 subjects had developed hypertension. After multiple adjustments, hyperfiltration is a risk for development of hypertension (OR: 1.374; 95% confidence incidence (CI), 1.013–1.864), as well as aging (OR: 1.063; 95% CI, 1.052–1.073), higher BMI (OR: 1.244; 95% CI, 1.200–1.289), and drinking habits (OR: 1.387, 95% CI, 1.117–1.721).

Conclusion

Hyperfiltration carries a significant risk for developing hypertension in Japanese individual without comorbidities. We should take account for hyperfiltration as a risk for hypertension, as well as chronic kidney diseases.

P1683Optimal serum uric acid levels for hypertension: 5-year cohort study

Background

Although hyperuricemia is known as a risk factor for hypertension, the optimal range of serum uric acid (SUA) for preventing hypertension has not been established, especially in a healthy population.

Methods

This is a 5-year cohort study to clarify the optimal SUA for hypertension. Subjects consisted of Japanese adults between 30 and 85 years of age were enrolled in the study at our Center for Preventive Medicine, and available at enrollment (2004) and at 5-year follow-up (2009). We excluded the study subjects who were hypertensive, diabetic, dyslipidemic, had a history of gout or hyperuricemia on medications, or if they had chronic kidney disease as estimated glomerular filtration rate <60 ml/min/1.73m2. Linear and logistic regression analyses were used to examine the relationship between each 1 mg/dL of serum uric acid range and development of hypertension with multiple adjustments for age, smoking, drinking habits, body mass index and baseline systolic blood pressure.

Results

Of 13,070 subjects enrolled at this step, we included 6,476 subjects (46.9±10.1 years old, 34.6% men) without comorbidities. The cumulative incidences of hypertension over 5 years were 5.9% in women and 12.1% in men. The lowest cumulative incidences of hypertension were 2.6% in 2.0–3.0 mg/dL of serum uric acid in women and 6.9% in 4.0–5.0 mg/dL in men. In contrast, the highest uric acid range showed highest cumulative incidence of hypertension both in women (28.6% in 8.0–9.0 mg/dL) and men (21.0% in ≥9.0 mg/dL). Hypouricemic (<2.0 mg/dL) subjects had higher cumulative incidences of hypertension than subjects with 2.0–3.0 mg/dL of serum uric acid levels, we excluded these subjects in multivariable logistic analysis. The odds ratio of 1 mg/dL increase of serum uric acid for developing hypertension was 1.395 (95% CI, 1.182–1.648) in women and 1.139 (95% CI, 1003–1.294) in men after multiple adjustments.

Conclusion

The optimal serum uric acid range for preventing hypertension was 2.0–3.0 mg/dL in women and 4.0–5.0 mg/dL in men. Higher uric acid levels increase cumulative incidence of hypertension.

Acknowledgement/Funding

None

Light wine consumption is associated with a lower odd for cardiovascular disease in chronic kidney disease

AIMS

To examine the association between wine consumption and the prevalence of chronic kidney disease (CKD) and cardiovascular disease (CVD).

DATA SYNTHESIS

We performed a cross-sectional logistic regression analysis of National Health and Nutrition Examination Survey (NHANES) in participants 21 years of age or older from 2003 to 2006 in a large representative study of the U.S.

POPULATION

Wine consumption was categorized as none (0 glass per day), light (<1 glass per day), or moderate (≥1 glasses per day). Prevalent CKD was defined as a urine albumin/creatinine ratio (UACR) ≥30 mg/g or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m². CVD was defined as history of CVD including angina, myocardial infarction, or stroke. Only 27 (0.5%) individuals reported moderate wine consumption, whereas 57.5% and 42% reported abstinence and light wine consumption, respectively. Light wine consumption was associated with a lower prevalence of CKD as opposed to abstinence in unadjusted analysis. After adjusting for demographics and CVD risk factors light wine consumption was associated with lower prevalence of CKD defined as UACR ≥30 mg/g but not with low eGFR. Furthermore, light wine consumption was associated with significantly lower rates of CVD in the general population and in subjects with CKD. The adjusted odd of CVD for those with light wine consumption was 0.72 (CI 0.52-0.99, p = 0.046) for the subjects with CKD.

CONCLUSION

These data suggest that light wine consumption (compared to abstinence) is associated with lower prevalence of CKD and a lower odd of CVD in those with CKD in the U.S.

Evaluation of hydrogen absorption cells for observations of the planetary coronas

Newly designed Lyman-alpha absorption cells for imaging hydrogen planetary corona were characterized using an ultra high resolution Fourier transform spectrometer installed on the DESIRS (Dichroïsme Et Spectroscopie par Interaction avec le Rayonnement Synchrotron) beamline of Synchrotron SOLEIL in France. The early absorption cell installed in the Japanese Mars orbiter NOZOMI launched in 1998 had not been sufficiently optimized due to its short development time. The new absorption cells are equipped with the ability to change various parameters, such as filament shape, applied power, H₂ gas pressure, and geometrical configuration. We found that the optical thickness of the new absorption cell was ∼4 times higher than the earlier one at the center wavelength of Lyman-alpha absorption, by optimizing the condition to promote thermal dissociation of H₂ molecules into two H atoms on a hot tungsten filament. The Doppler temperature of planetary coronas could be determined with an accuracy better than 100 K with the performance of the newly developed absorption cell.

Effect of Antihypertensive Drugs on Uric Acid Metabolism in Patients with Hypertension: Cross-Sectional Cohort Study

Background: Hypertension is a common complication in patients with gout and/or hyperuricemia. Besides, hyperuricemia is a risk factor of gout as well as ischemic heart disease in hypertensive patients. Moreover, the risk of gout is modified by antihypertensive drugs. However, it remains unclear how antihypertensive agents affect uric acid metabolism. Purpose: In the present study, we investigated the uric acid metabolism in treated hypertensive patients to find out whether any of them would influence serum levels of uric acid. Patients and methods: 751 hypertensive patients (313 men and 438 women) under antihypertensive treatment were selected. Blood pressure (BP), serum uric acid (SUA) and serum creatinine (Scr) were measured and evaluated statistically. Results: In patients treated with diuretics, beta-blockers and/or alpha-1 blockers SUA levels were significantly higher than in patients who were not taking these drugs. Besides, the estimated glomerular filtration rate (eGFR) in patients treated with diuretics, beta-blockers and/or alpha-1 blockers was negatively correlated with SUA level. There were gender differences in the effects of beta-blockers and alpha-1 blockers. Multiple regression analysis indicated that both diuretics and beta-blockers significantly contributed to hyperuricemia in patients with medication for hypertension. Conclusion: Diuretics, beta-blockers and alpha-1 blockers reduced glomerular filtration rate and raised SUA levels. Calcium channel blockers, ACE inhibitors and angiotensin receptor blockers, including losartan, did not increase SUA levels.

T-staging of gastric cancer of air-filling multidetector-row CT: comparison with hydro-multidetector-row CT

PURPOSE

The purpose of this study was to evaluate the accuracy of T-staging of gastric cancer by air-filling multidetector-row CT (air-MDCT) compared with water-filling MDCT (hydro-MDCT).

MATERIALS AND METHODS

One hundred fifteen patients with histologically diagnosed gastric cancer were included in this study. Fifty-eight patients underwent air-MDCT, and the remaining 57 had hydro-MDCT using a 64-channel scanner. Based on the volumetric data of contrast-enhanced MDCT obtained about 75 s after intravenously injecting 525 mg iodine per kilogram patients weight (525 mgI/kg) nonionic contrast material at the rate of 2 ml/s, oblique coronal and oblique sagittal multi-planar reformatted images perpendicular to the stomach wall, including the tumor, were reconstructed on a workstation. Mural invasion of gastric cancer into the gastric wall, as visualized by CT, was classified according to the TNM classification, and the results of T-staging by MDCT were compared with those by pathologic analysis after surgery.

RESULTS

Correct assessment of T-staging by air-CT was achieved in 48 of 58 patients (83%), and that by hydro-MDCT was 49 of 57 patients (86%). The sensitivity, specificity, and accuracy of the technique in determining the invasion of serosa were 88%, 93%, and 91% for air-CT and 83%, 95%, and 91% for hydro-CT. There were no significant differences between hydro-MDCT and air-MDCT in sensitivity (P=0.73), specificity (P=0.71) and accuracy (P=0.98).

CONCLUSION

Air-MDCT is a very valuable tool in T-staging of gastric cancer as well as hydro-MDCT.

Regional differences in hypertensive cardiovascular remodeling between fishing and farming communities in Japan

BACKGROUND

Effects of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) intake on the cardiovascular system have been reported, and thus we hypothesized that the prevalence of hypertensive cardiovascular remodeling would be lower in a fishing than a farming community.

METHODS

We recruited 263 essential hypertensives from a fishing and 333 from a farming village; all subjects were ≥40 years (mean 73 years; 42% men). They were cross-sectionally examined for serum eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), asymmetric dimethylarginine (ADMA) levels, left ventricular mass index (LVMI), and common-carotid artery (CCA) and internal-carotid artery (ICA) intima-media thickness (IMT).

RESULTS

Compared to the patients in the farming village, those in the fishing village had higher serum EPA and DHA levels (63.3 vs.70.9 µg/ml, 137.2 vs.157.8 µg/ml) and lower ADMA levels (0.49 vs.0.47 nmol/ml; all P < 0.05). LVMI and both CCA-IMT and ICA-IMT levels were lower in the fishing than the farming village (113.2 vs.121.6 g/m(2), 0.88 vs.0.94 mm, 1.10 vs.1.17 mm: all P < 0.01) even after adjustment for age, sex, body mass index (BMI), duration of hypertensive medication, number of antihypertensive medications, and 24-h systolic blood pressure (SBP) level. The differences in LVMI and IMT levels between these communities also remained unchanged (all P < 0.01) after additional adjustment for the regional differences in EPA, DHA, and ADMA levels. A multivariable linear regression analysis showed that the difference in place of residence was independently associated with LVMI as well as with both CCA-IMT and ICA-IMT levels (all P < 0.01).

CONCLUSION

The prevalence of cardiovascular remodeling was significantly lower in patients in the fishing community than in those in the farming community. Further investigations are required to explain the mechanisms underlying this association.

Integrated FDG-PET/CT compared with intravenous contrast-enhanced CT for evaluation of metastatic regional lymph nodes in patients with resectable early stage esophageal cancer

OBJECTIVE

To assess whether integrated fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) can improve the diagnostic accuracy of metastatic regional lymph nodes (LNs) in esophageal cancer compared with contrast enhanced CT (CECT).

METHODS

We examined 180 consecutive patients with esophageal cancer by integrated PET/CT between April 2006 and March 2007. Eighteen patients (M:F 14:4) underwent radical esophagectomy after evaluations by PET/CT and CECT of 5-7-mm-thick slices 70-80 s after injection. Regional LNs of esophageal cancer were retrospectively reviewed on CECT images by two blinded evaluators on the basis of the following cutoff sizes: 7 mm for all regional LNs (Protocol A), 10 mm for paratracheal LNs (Protocol B), and 7 mm for others. In addition, the maximum standardized uptake value (SUVmax) on PET/CT was evaluated for positive uptake by LNs.

RESULTS

Of 210 LNs excised at surgery, 25 were positive and 185 were negative for metastasis at pathology. The PET/CT images identified 15 true-positive and 184 true-negative LNs, whereas CECT identified 15 true positives and 176 true negatives in Protocol A, and 14 true positives and 180 true negative in Protocol B. The sensitivity, specificity, accuracy, positive, and negative predictive values of PET/CT were respectively 60.0%, 99.5%, 94.8%, 93.8%, and 94.8%, whereas those of CECT were 60.0%, 95.1%, 91.0%, 62.5%, and 94.6% (Protocol A) and 56.0%, 97.3%, 92.4%, 73.7%, and 94.2% (Protocol B). A comparison of the two CECT protocols revealed fewer false-positive LNs in Protocol B, but slightly lower sensitivity in Protocol B than in Protocol A. Substantial numbers of false-positive LNs were determined by CECT in the paratracheal regions (6 of 9, 66.7%) and CECT revealed central necrosis in 4 of 15 (26.7%) true-positive LNs > 1.8 cm. The mean SUVmax on PET/CT was 2.9 (range 1.7-5.5) in true-positive LNs. The smallest LN metastasis detectable by PET/CT was 6 mm.

CONCLUSIONS

Integrated PET/CT improves the PPV of regional LNs when compared with CECT.

"Prominent ear sign" on diffusion-weighted magnetic resonance imaging in relapsing polychondritis

Relapsing polychondritis is a rare autoimmune disease characterized by recurrent inflammation of cartilage in multiple sites of the body, including the auricles. Central nervous system involvement appears rare. We encountered a case of relapsing polychondritis with encephalitis that could be diagnosed by the unique appearance of the auricle with signal hyperintensity on diffusion-weighted magnetic resonance imaging.

Whole-body MRI for detecting metastatic bone tumor: diagnostic value of diffusion-weighted images

PURPOSE

We assessed the diagnostic value of whole body magnetic resonance (MR) imaging (WB-MRI) using diffusion-weighted images (DWI) for detecting bone metastasis and compared it with that of skeletal scintigraphy (SS).

MATERIALS AND METHODS

Thirty patients with malignancies (breast cancer, 17 patients; prostate cancer, 9; and one patient each, thyroid cancer, liposarcoma, leiomyosarcoma, and extraskeletal Ewing sarcoma) underwent both WB-MRI and SS to detect bone metastasis. All patients were followed more than 6 months by MR imaging, SS, or computed tomographic (CT) examination. For WB-MRI, patients were placed in feet-first supine position with table-top extender and quadrature body coil. We acquired DWI (axial plane from lower neck to proximal femur) (single shot short TI inversion-recovery [STIR]: repetition time [TR] 6243/echo time [TE] 59/inversion time [TI] 180 ms; b value: 600 s/mm(2); 5-mm slice thickness; 112 x 112 matrix), T(1)-weighted fast spin echo (T(1)WI), and STIR (sagittal plane of total spine images and coronal plane of whole body images) images. Four blinded readers independently and separately interpreted images of combined MR sequences of T(1)WI+STIR (session 1) and T(1)WI+STIR+DWI (session 2).

RESULTS

In 10 of 30 patients, we detected a total of 52 metastatic bone lesions; in the other 20, follow-up examinations confirmed no metastatic bone lesions. For these 52 lesions, for session 2, the mean sensitivity was 96% and the positive predictive value (PPV) was 98%. Those values were superior to those of session 1 (sensitivity: 88%; PPV: 95%) and those of SS (sensitivity: 96%; PPV: 94%).

CONCLUSION

WB-MRI that included DWI was useful for detecting bone metastasis.

Hypervascular hepatocellular carcinoma: Combined dynamic MDCT and SPIO-enhanced MRI versus combined CTHA and CTAP

AIM

Recently, many diagnostic modalities have been developed for the detection of hepatocellular carcinoma (HCC). Of these, a less invasive and more accurate diagnostic procedure is desirable. This study was undertaken to compare combined dynamic multidetector row helical computerized tomography (MDCT) and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) with combined CT hepatic arteriography (CTHA) and CT during arterial portography (CTAP) for the detection of hypervascular HCC.

METHODS

Forty-eight patients with 56 pathologically proved hypervascular HCCs (less than 5.0 cm in diameter) underwent dynamic MDCT and SPIO-enhanced MRI, as well as CTHA and CTAP. The images were reviewed by four independent and blinded readers on a tumor-by-tumor basis.

RESULTS

The mean areas under alternative-free response receiver operating characteristic curve (Az) for combined dynamic MDCT and SPIO-enhanced MRI (IV set) and combinedCTHA and CTAP (IA set) were comparable (0.948 and 0.969, respectively, P > 0.05), although the Az value of the IV set was significantly lower than that of the IA set in HCCs smaller than or equal to 1.5 cm (0.867 and 0.937, respectively, P = 0.033). The mean sensitivity and positive predictive value of the IV set were similar to those of the IA set.

CONCLUSIONS

Combined dynamic MDCT and SPIO-enhanced MRI showed a diagnostic accuracy comparable to intra-arterial contrast-enhanced CT (CTHA and CTAP) for hypervascular HCC, and may be a useful diagnostic option prior to curative treatments of hypervascular HCC, although a limitation exists in detecting HCCs smaller than or equal to 1.5 cm.

[Torsion of the right upper lobe due to primary lung cancer with pulmonary hypertrophic osteoarthropathy; report of a case]

A 61-year-old woman was admitted due to severe coughing. Chest X-ray revealed a mass in the right lower lung field at standing position and in the right upper lung field at supine position. A position of the mass changed with change in her posture because of lobar torsion. Bronchoscopic biopsy of the polypoid tumor obstructing the right upper bronchus revealed adenocarcinoma. She had hypertrophic osteoarthropathy simultaneously. Right pneumonectomy was performed. Postoperative course has been uneventful for 3 years.

Principles and techniques of transcatheter embolotherapy for peripheral vascular lesions

Transcatheter embolotherapy (TCE), a common procedure for interventional radiologists, comprises transcatheter delivery of embolic agents into target vessels in order to eliminate lesions or lesion-associated symptoms. Good knowledge of delivery catheters and embolic agents is essential to optimize embolization techniques and to obtain the desired therapeutic outcomes. In this review, we describe the principles and techniques of TCE for peripheral arterial and venous lesions featuring visceral aneurysms, peripheral and pulmonary arteriovenous malformations (AVMs), and varicoceles.

Noninvasive method using multidetector CT for calculating the relative blood supply ratio of duplicated renal arteries in renal donors

PURPOSE

The aim of this study was to evaluate the correlation between the renal artery cross-sectional area measured by multidetector computed tomography (MDCT) and the nephrogram area calculated by renal arteriography in potential living renal donors with duplicated renal arteries.

MATERIALS AND METHODS

Medical records of 18 patients with duplicated renal arteries who underwent both MDCT angiography and renal arteriography between 2001 and 2003 were retrospectively reviewed. All 20 kidneys were evaluated. Renal artery cross-sectional areas were measured using the workstation to which the CT data were transferred; the nephrogram areas on the digitized angiographic images were calculated using public domain software. Bland-Altman analysis was performed to compare the cross-sectional area ratio of the accessory arteries to the main renal arteries, with the ratios obtained from the nephrogram areas calculated from the arteriograms.

RESULTS

The mean cross-sectional areas of the accessory and main renal arteries were 6.78 and 20.9 mm2, respectively. The ratio of the nephrogram areas calculated from the arteriograms ranged from 0.094 to 0.809. Bland-Altman analysis showed no significant difference.

CONCLUSION

It is possible to predict the supply volume of accessory renal arteries by measuring the cross-sectional area of the accessory and main renal arteries in potential living renal donors.

Hepatic metastases: detection with multi-detector row CT, SPIO-enhanced MR imaging, and both techniques combined

PURPOSE

To retrospectively compare the accuracy in detection of hepatic metastases among contrast material-enhanced multi-detector row computed tomography (CT) alone, superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging alone, and a combination of contrast-enhanced CT and SPIO-enhanced MR imaging.

MATERIALS AND METHODS

The ethics committee did not require its approval or informed consent for this retrospective study, which was compliant with Declaration of Helsinki principles. Data in 38 patients (22 men, 16 women; mean age, 64.5 years; range, 35-78 years) suspected of having hepatic metastases who underwent both contrast-enhanced CT and SPIO-enhanced MR imaging were retrospectively analyzed. Twenty-one of the 38 patients had 61 metastases. Seventeen of the 61 metastases were confirmed histologically; the remaining 44 metastases were defined with imaging follow-up. At MR imaging, SPIO-enhanced heavily T1-weighted images, T2*-weighted gradient echo images, and T2-weighted fast spin-echo images were evaluated. Contrast-enhanced multi-detector row CT images obtained in the portal phase were evaluated. Four blinded observers independently reviewed CT images, MR images, and the combination of CT and MR images. Diagnostic accuracy was evaluated by using the alternative free-response receiver operating characteristic (AFROC) method. Sensitivities and positive predictive values were also analyzed with the Fisher protected least significant difference test and generalized estimating equations.

RESULTS

The mean area under the AFROC curve for the combined approach (0.70) was significantly higher than that for SPIO-enhanced MR imaging alone (0.58, P < .05, Fisher protected least significant difference test), and there was no significant difference between each of them and that for contrast-enhanced CT alone (0.66). For all lesions, the mean sensitivity of combined imaging (0.59) was significantly higher than that of CT (0.48) or MR imaging (0.43) alone (P < .05, Fisher protected least significant difference test and generalized estimating equations). For all lesions, the mean positive predictive values were 0.82, 0.89, and 0.81, for combined MR and CT, CT alone, and MR alone, respectively.

CONCLUSION

The addition of SPIO-enhanced MR imaging to contrast-enhanced multi-detector row CT (ie, combined analysis of SPIO-enhanced MR images and contrast-enhanced CT images) can improve sensitivity in the detection of hepatic metastases, although this improvement in sensitivity was not significant at AFROC analysis.

Assessment of Two 3D MDCT Colonography Protocols for Observation of Colorectal Polyps

OBJECTIVE

The objective of our study was to assess the value of two-way interpretation (i.e., from rectum to cecum and vice versa) compared with one-way interpretation (i.e., from rectum to cecum only) in terms of polyp detection and interpretation time on MDCT colonography.

MATERIALS AND METHODS

Fifty consecutive patients underwent both CT colonography and conventional colonoscopy. Three radiologists independently analyzed the CT colonographic examinations of each patient using a primary 3D method. All examinations were analyzed using two techniques: navigation from rectum to cecum only (one-way) and navigation from rectum to cecum and vice versa (two-way). Sensitivity and positive predictive value were calculated on both a per-polyp basis and a per-patient basis. Alternative free-response receiver operating characteristic (ROC) curve analysis was estimated, and image interpretation time was documented.

RESULTS

One hundred fifty-five polyps were depicted in 45 patients by colonoscopy. The mean sensitivity of CT colonography for polyp detection with two-way (88.4%) was significantly superior to that with one-way (78.1%) (p < 0.01). The mean positive predictive value of each observer with one-way was 66.7%, whereas that with two-way was 65.8%. The mean area under the alternative free-response ROC curve (A(z) value) with two-way (0.827) was higher than that with one-way (0.816), but there was not a statistically significant difference. The average interpretation time of each observer with two-way (39 min) was statistically significantly longer than that with one-way (25 min) (p < 0.01).

CONCLUSION

When using a primary 3D interpretation technique at CT colonography, complete 3D navigation from rectum to cecum and from cecum to rectum is mandatory to maximize polyp detection. The image interpretation time for two-way interpretation is statistically significantly longer than that with one-way interpretation.

Urodynamic study on postsurgical bladder function in cervical cancer treated with systematic nerve-sparing radical hysterectomy

The objective of this study was to assess the postsurgical bladder function by urodynamic study in patients with cervical cancer treated with nerve-sparing radical hysterectomy. A total of 27 consecutive patients were included in the study. Of the 27 patients, autonomic nerves had been completely preserved at least on one side in 22 patients (group A), and autonomic nerves could not be successfully preserved in five patients (group B). In group A, there was no significant difference in compliance at the moment of strong desire to void, maximum flow rate, and residual urine volume between before the operation and at 12 months after the operation. However, abdominal pressure at maximum flow had significantly increased in patients of group B than of group A. Detrusor contraction pressure at maximum flow had significantly decreased in patients of group B than of group A. Bladder sensation was diminished in three cases (60%) of group B but preserved in all the patients of group A. Although it is still preliminary, our surgical technique described in this report is thought to be effective for preservation of bladder function. For further evaluation of the efficacy of nerve-sparing radical hysterectomy in terms of quality of life and survival of patients, a prospective randomized trial needs to be performed.

Post-irradiation hypoxic incubation of X-irradiated MOLT-4 cells reduces apoptotic cell death by changing the intracellular redox state and modulating SAPK/JNK pathways

To elucidate radiobiological effects of hypoxia on X-ray-induced apoptosis, MOLT-4 cells were treated under four set of conditions: (1) both X irradiation and incubation under normoxia, (2) X irradiation under hypoxia and subsequent incubation under normoxia, (3) X irradiation under normoxia and subsequent incubation under hypoxia, and (4) both X irradiation and incubation under hypoxia, and the induction of apoptosis was examined by fluorescence microscopy. About 28-33% apoptosis was observed in cells treated under conditions 1 and 2, but this value was significantly reduced to around 18-20% in cells treated under conditions 3 and 4, suggesting that post-irradiation hypoxic incubation rather than hypoxic irradiation mainly caused the reduction of apoptosis. The activation and expression of apoptosis signal-related molecules SAPK/JNK, Fas and caspase-3 were also suppressed by hypoxic incubation. Effects of hypoxic incubation were canceled when cells were treated under conditions 3 and 4 with an oxygen-mimicking hypoxic cell radiosensitizer, whereas the addition of N-acetyl-L-cysteine again reduced the induction of apoptosis. From these results it was concluded that hypoxia reduced the induction of apoptosis by changing the intracellular redox state, followed by the regulation of apoptotic signals in X-irradiated MOLT-4 cells.

Effects of antioxidants on X-ray- or hyperthermia-induced apoptosis in human lymphoma U937 cells

Hydroxyl radicals (.OH) and superoxide anion radicals (O2.-) are known to play cardinal roles in cell killing and various types of cell damage. In order to elucidate the mechanism of the involvement of both free radicals on apoptosis, the correlation between anti-apoptotic effects and free radical scavenging abilities of anti-oxidants was studied. As an indicator of anti-apoptotic effects, C1/2 (antioxidant concentration to inhibit DNA fragmentation by 50%) was evaluated in human lymphoma cell line U937 cells 6 hr after X-ray (10 Gy) or hyperthermia (44 degrees C, 30 min) treatment. Rate constants of the reactions between antioxidants and .OH or O2.- were calculated as the scavenging ability of the antioxidants with graded concentration estimated by EPR spectroscopy. No apparent correlation between C1/2 obtained in apoptosis induced by X-rays or hyperthermia and the rate constants of antioxidants for .OH or O2.- was observed. On the other hand, the partition coefficients in 1-octanol/water of the antioxidants, an indicator of hydrophobicity, revealed a correlation with the C1/2 of the agents with hyperthermia, but not with X-ray irradiation. These results indicate that the prevention of apoptosis by an antioxidant is not simply associated with its scavenging ability for .OH or O2.-. The hydrophobicity of the antioxidant, among other possible factors, is involved in the inhibition of hyperthermia- induced apoptosis.

No evidence for adaptation of current egg drop syndrome 1976 viruses to chickens

In order to determine whether the current field strains of egg drop syndrome (EDS) 1976 viruses adapt to chickens, we compared the growth efficiency of three Japanese field strains (PA-1/79, AWI/98, Gifu/01) in chicken and duck embryo liver cells. The growth efficiency in chicken or duck embryo liver cells was almost similar in these strains. The fiber protein may carry the type-specific antigen and the hemagglutination activity, and hexon protein may contain the subgroup-specific antigenic determinants. Therefore, the fiber head and hexon loop 1 DNA domain sequences of the six Japanese field strains UPA-1/79, ME/80, 44/81, Kyoto/91, AWI/98, Gifu/01) were compared, but these DNA domains were identical among the six field strains. Our data suggested that the EDS virus was maintained without discernible changes for the last two decades in the field.

Characterization of JNK-like protein derived from a mosquito cell line, C6/36

When Western blot analysis of heat-killed bacteria- and lipopolysaccharide (LPS)-treated Aedes albopictus mosquito cell line C6/36 was performed using antiphospholyrated c-Jun amino-terminal kinase (JNK) antibodies, approximately 46 kDa protein was clearly detected with a peak around 30 min. After the C6/36 cells were incubated at 45 degrees C in order to induce apoptosis, the 46 kDa protein continued to be detected for at least 3 h. The internalization of fluorescein-labelled bacteria was inhibited by a JNK-specific inhibitor SP600125, suggesting that phagocytosis involves the JNK signalling pathway in mosquito cells. Based on these results, we found one candidate for the nucleotide sequence of JNK (Ae-JNK) from the C6/36 cells. This study is the first report regarding the mitogen-activated protein kinase (MAPK) of mosquito.

Ex vivo expansion of human UC blood primitive hematopoietic progenitors and transplantable stem cells using human primary BM stromal cells and human AB serum

BACKGROUND

In vitro maintenance and expansion of human hematopoietic stem cells is crucial for many clinical applications, and investigators have been using xenogeneic, especially murine, stromal cells for stem-cell expansion. In addition, many such culture systems utilize FCS-containing medium or serum-free medium that contains human- or animal-derived proteins. However, the possible transmission of infectious diseases has led to a debate about the safety of the delivery of grafts expanded in culture using cells and proteins of allogeneic or xenogeneic origin. Using primary human BM stromal cells, we have established an AB serum-based co-culture system to expand human primitive progenitors and transplantable stem cells.

METHODS

Cord blood CD34+ cells were cultured on a monolayer of human BM-derived primary stromal cells with thrombopoietin (TPO), stem-cell factor (SCF) and flt3/flk2 ligand (FL) in the presence of either FCS or AB serum. One to three weeks later, cells were examined for total cells, CD34+ cells, CD34+ CD38- cells, and clonogenic progenitors. SCID mouse reconstituting cell (SRC) activity was also studied.

RESULTS

Three weeks of culture with TPO, SCF, and FL supported more than a 250-fold expansion of CD34+ cells, CD34+ CD38- cells and CFU-C, regardless of the kind of serum used. SRC assay revealed that transplantable stem cells were moderately expanded as well.

DISCUSSION

This ex vivo expansion system should prove valuable in clinical settings in which stromal cells and serum are available from recipients or stem-cell donors.

Lung herniation as an anatomic consequence of pneumonectomy

BACKGROUND

Pneumonectomy causes an overdistention of the remaining lung as an adaptive response. Excessive lung herniation occasionally causes serious lung dysfunction.

METHODS

Twenty-seven patients were selected from 152 patients who underwent pneumonectomy for lung cancer between 1990 and 1998. Complete resections were accomplished; no recurrence was observed for 3 years in these 27 patients. To evaluate the extent of herniation, the Lung Herniation Index (LHI) was developed and defined as the sum of proportions of the maximal transverse length of the remaining lung divided by the transverse length of the thoracic cavity, measured at the level of the aortic arch and the inferior pulmonary vein on chest computed tomography. Sequential changes in LHI were compared between groups.

RESULTS

Changes in LHI did not differ between groups delineated on the basis of an FEV1 of 70 % (p = 0.45) and RV/TLC of 40 % (p = 0.99). Patients with a low body mass index (BMI) (< 20 kg/m(2)), however, showed a significantly greater degree of lung herniation than those with a high BMI (> or = 20 kg/m(2)) (p < 0.05).

CONCLUSIONS

Concomitant COPD has no effect on lung herniation. Some preventive procedure should be considered for patients with low BMI.

Hypoxia and etanidazole alter radiation-induced apoptosis in HL60 cells but not in MOLT-4 cells

PURPOSE

To examine how hypoxia influences ionizing irradiation-induced apoptosis in cultured mammalian cells and how a hypoxic cell radiosensitizer sensitizes apoptosis under hypoxic conditions.

MATERIALS AND METHODS

Two cell lines derived from human lymphocytes, HL60 and MOLT-4, were exposed to 15 Gy X-rays under aerobic and hypoxic conditions. Etanidazole was used as a hypoxic cell radiosensitizer. The apoptotic morphological changes of nuclei and the induction of ladder-like DNA fragmentation were assessed by fluorescence microscopy and agarose gel electrophoresis, respectively.

RESULTS

In HL60 cells, apototic cell death and the activation of caspases 8, 9 and 3 were less induced under the hypoxic conditions than under the aerobic ones. Treatment of hypoxic cells with etanidazole enhanced X-ray-induced apoptosis and caspase activation. However, in MOLT-4 cells, neither hypoxia nor etanidazole influenced X-ray-induced apoptosis and caspase activation. In both cell lines, the frequency of X-ray-induced DNA double-strand breaks (DSB) under hypoxia was significantly smaller than that in aerobic conditions. Treatment of hypoxic cells with etanidazole enhanced them.

CONCLUSION

These results suggested that X-ray-induced apoptosis in HL60 cells was initiated by DNA DSB and the treatment of hypoxic cells with etanidazole sensitized them through the enhancement of DSB induction, whereas X-ray-induced apoptosis in MOLT-4 cells occurred through damage other than to DNA.

An amebic lung abscess: report of a case

Recently the number of amebiasis cases has increased in Japan. Pleuropulmonary amebiasis is a very rare complication of liver amebiasis. We report herein the case of a 54-year-old man presenting with an amebic lung abscess in his right lower lung. The diagnosis of lung amebiasis was established from a direct examination of the pus in which trophozoites of Entamoeba histolytica were detected. After the oral administration of metronidazole, the laboratory findings improved and he thus underwent a right lower lobectomy. He was discharged without any relapse of infection 20 days after a thoracotomy. We conclude that a protozoan infection should thus be suspected in the case of a pleuropulmonary infection in which several types of antibiotics prove to be ineffective.

[A case report of pulmonary blastoma--biphasic pulmonary blastoma]

We report a biphasic pulmonary blastoma in a 77-year-old man. In a routine chest radiographic examination, in the left upper lung field, a massive shadow that had been entirely absent one year before was detected. The preoperative imaging films showed a 10 x 8 cm, well-circumscribed solid tumor in the upper lobe of the left lung. A preoperative clinical diagnosis of primary lung cancer was considered. The intraoperative findings were that the tumor had invaded the visceral pleura with adhesion to the parietal pleura. Left upper lobectomy with lymph node sampling was performed, and since invasion of the pulmonary artery wall was confirmed, complete removal of tumor was not possible. The postoperative diagnosis was biphasic pulmonary blastoma. The patient was treated with radiotherapy up to a limit of 50 Gy, covering the area around of the left hilum. At the latest follow-up, 1 year postoperatively, the patient was clinically and radiologically free of the disease.

p38 MAPK and Ca2+ contribute to hydrogen peroxide-induced increase of permeability in vascular endothelial cells but ERK does not

To examine the involvement of p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal-regulated kinase (ERK) in the oxidative stress-induced increase of permeability in endothelial cells, the effects of a p38 MAPK inhibitor (SB203580) and ERK inhibitor (PD90859) on the H2O2-induced increase of permeability in bovine pulmonary artery endothelial cells (BPAEC) were investigated using a two-compartment system partitioned by a semi-permeable filter. H2O2 at 1 mM caused an increase of the permeation rate of fluorescein isothiocyanate (FITC)-labeled dextran 40 through BPAEC monolayers. SB203580 inhibited the H2O2-induced increase of permeability but PD98059 did not, though activation (phosphorylation) of both p38 MAPK and ERK was observed in H2O2-treated cells in Western blot analysis. An H2O2-induced increase of the intracellular Ca2+ concentration ([Ca2+]i) was also observed and an intracellular Ca2+ chelator (BAPTA-AM) significantly inhibited the H2O2-induced increase of permeability. However, it showed no inhibitory effects on the H2O2-induced phosphorylation of p38 MAPK and ERK. The H2O2-induced increase of [Ca2+]i was not influenced by SB203580 and PD98059. These results indicate that the activation of p38 MAPK and the increase of [Ca2+]i are essential for the H2O2-induced increase of endothelial permeability and that ERK is not.

Induction of neurite outgrowth in PC12 cells by alpha -phenyl-N-tert-butylnitron through activation of protein kinase C and the Ras-extracellular signal-regulated kinase pathway

The spin trap alpha-phenyl-N-tert-butylnitron (PBN) is widely used for studies of the biological effects of free radicals. We previously reported the protective effects of PBN against ischemia-reperfusion injury in gerbil hippocampus by its activation of extracellular signal-regulated kinase (ERK) and suppression of both stress-activated protein kinase and p38 mitogen-activated protein kinase. In the present study, we found that PBN induced neurite outgrowth accompanied by ERK activation in PC12 cells in a dose-dependent manner. The induction of neurite outgrowth was inhibited significantly not only by transient transfection of PC12 cells with dominant negative Ras, but also by treatment with mitogen-activated protein kinase/ERK kinase inhibitor PD98059. The activation of receptor tyrosine kinase TrkA was not involved in PBN-induced neurite outgrowth. A protein kinase C (PKC) inhibitor, GF109203X, was found to inhibit neurite outgrowth. The activation of PKCepsilon was observed after PBN stimulation. PBN-induced neurite outgrowth and ERK activation were counteracted by the thiol-based antioxidant N-acetylcysteine. From these results, it was concluded that PBN induced neurite outgrowth in PC12 cells through activation of the Ras-ERK pathway and PKC.

Superoxide generation from human polymorphonuclear leukocytes by liposome-encapsulated hemoglobin

We investigated the interactions between liposome-encapsulated hemoglobin (Neo Red Cells: NRC) and human polymorphonuclear leukocytes as assessed by superoxide generation. NRC triggered superoxide generation from neutrophils in a dose-dependent manner. Empty liposomes also induced superoxide production of neutrophils. Superoxide generation of neutrophils induced by phorbol myristate acetate (PMA) was delayed but intensified both by NRC and empty liposomes. The intensity of superoxide generation induced by NRC was smaller than that by the empty liposomes. As NRC contained superoxide dismutase (SOD) that was copurified with hemoglobin from red blood cells and its activity remained, SOD contained in NRC may partially eliminate superoxide.

Role of lipophilicity and hydrogen peroxide formation in the cytotoxicity of flavonols

We compared the lipophilicity and toxicity of the four flavonols, galangin, kaempferol, quercetin and myricetin, which respectively have no, one, two and three hydroxyl groups on the B-ring. The lipophilicity was in the order of myricetin < quercetin < kaempferol < galangin. The cytotoxicity determined by a colony-formation assay with Chinese hamster lung fibroblast V79 cells was in the order of quercetin < kaempferol < galangin < myricetin. Apart from myricetin, the order of lipophilicity was the same as that of cytotoxicity, implying that the cytotoxicity was attributable to the lipophilicity. The cytotoxicity of myricetin was attributable to the hydrogen peroxide formed by autoxidation.

Three-dimensional magnetic resonance imaging of lung and liver tumors in mice by use of transversal multislice magnetic resonance images

PURPOSE

To diagnose lung and liver tumors experimentally induced in mice in three-dimensional magnetic resonance (MR) images constructed by superimposing transversal multislice MR images of thoracic and abdominal regions taken under a high magnetic field of 7.05 tesla (T).

METHODS

Lung and liver tumors were induced by administration of urethane to A/J mice and implantation of transplantable colon-26 cells into BALB/c mice, respectively. Two-dimensional (2-D) multislice MR images from the thoracic to abdominal regions were taken under the proton density-weighted conditions. Each organ in the 2-D MR images was pseudocolored, and a three-dimensional (3-D) image was constructed by superimposing them on a UNIX computer, using volume-rendering software.

RESULTS

In the normal mouse, each organ in the thoracic and abdominal regions was three-dimensionally imaged and was clearly distinguished from the others. In mice with tumors in the lung or liver, the pathologic changes in the tissue could be visualized in 3-D images.

CONCLUSIONS

The MR images three-dimensionally constructed by use of a method combining MR imaging under a high magnetic field of 7.05 T and a computer technique using volume-rendering software was useful for diagnosis of lung and liver tumors experimentally induced in mice.

Isolation, characterization, and cDNA cloning of chicken turpentine-induced protein, a new member of the scavenger receptor cysteine-rich (SRCR) family of proteins

Acute-phase serum proteins were induced by administrating a chicken with turpentine oil. One of these proteins was a new protein that appeared in front of albumin in polyacrylamide disc gel electrophoresis using a 4.5-16% gel. To purify this protein, turpentine-administrated chicken serum was fractionated by ammonium sulfate precipitation at 50% saturation, and the supernatant fraction was chromatographed on a DEAE-Toyopearl 650S column. The purified protein is a mannose-glycoprotein, and its N-terminal sequence, determined by the Edoman method, is not homologous from that of other reported acute-phase proteins. An analysis of physiological function with two different test systems, chemiluminescence measurement and electron spin resonance spectroscopy, showed that the purified protein has antioxidant activity and inhibits superoxide (O(2)) mediated by activation of the receptor. In support of these results, the complete amino acid sequence of 18-B is homologous to the scavenger receptor cysteine-rich (SRCR) family of proteins that participate in the regulation of leukocyte function. 18-B is composed of four SRCR domains, which is different from the previously characterized SRCR family of proteins such as Spalpha, CD6, and CD163. These findings indicate that turpentine-induced 18-B, a new member of scavenger receptor cysteine-rich family, may be implicated in regulation of cell function in a manner of inhibition of the overproduction of the reactive oxygen species.

Serum-free coculture system for ex vivo expansion of human cord blood primitive progenitors and SCID mouse-reconstituting cells using human bone marrow primary stromal cells

OBJECTIVE

In an attempt to maintain and expand human stem cells, many investigators have used xenogeneic, especially murine, stromal cells and fetal calf serum. Because of the possible transmission of infectious diseases, however, the safety of the delivery of grafts expanded in culture using xenogeneic cells and serum has been debated. Using primary human marrow stromal cells, we established a novel serum-free culture system to expand human primitive progenitors and transplantable stem cells.

MATERIALS AND METHODS

Cord blood CD34(+) cells were cultured on a monolayer of human primary marrow stromal cells in the presence of thrombopoietin (TPO), flt3/flk2 ligand (FL), and/or stem cell factor (SCF) under serum-free conditions. After 2 or 4 weeks of culture, cells were examined for clonogenic progenitors and severe combined immunodeficient disorder (SCID) mouse-reconstituting cells (SRC).

RESULTS

In the presence of TPO, FL, and SCF, marrow stromal cells supported more than a 100- and 1,000-fold expansion of CD34(+) cells and colony-forming units in culture after 2 and 4 weeks of incubation, respectively. In addition, cobblestone area-forming cells were expanded more than 18- and 60-fold after 2 and 4 weeks of culture, respectively. Furthermore, SRC assay demonstrated augmented engraftment by cultured cells.

CONCLUSION

This ex vivo expansion system should prove valuable in clinical settings in which stromal cells are available from recipients or stem cell donors.

Two cases of severe bronchopneumonia due to influenza A (H3N2) virus: detection of influenza virus gene using reverse transcription polymerase chain reaction

We report two cases of severe bronchopneumonia due to influenza A (H3N2) virus. The severity of the disease necessitated initiation of empiric therapy based on the present illness and clinical data on admission. Both patients were improved by artificial ventilation with positive end-expiratory pressures and administration of broad spectrum antibiotics and corticosteroids before confirming the diagnosis of viral bronchopneumonia using viral culture and serological tests. Within 24 hours, influenza A (H3N2) virus was identified by amplification of the pathogen genes by reverse transcription polymerase chain reaction (RT-PCR) using the stored bronchoalveolar lavage (BAL) fluids of both cases. This suggests that a combination of detection methods of pathogens using RT-PCR and BAL fluid will facilitate determination of rational treatment aimed at influenza A virus.

ESR detection of intraphagosomal superoxide in polymorphonuclear leukocytes using 5-(diethoxyphosphoryl)-5-methyl-l-pyrroline-N-oxide

We applied a spin trap, 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO), to detect O2*- generation during phagocytosis in human polymorphonuclear leukocytes (PMNs). PMNs were activated with serum-opsonized zymosan (sOZ) in the presence of DEPMPO. The ESR spectra mainly consisted of Cu,Zn-SOD-sensitive DEPMPO-OOH spin adducts. To clarify where these spin-adducts were present, cells after stimulation were separated from extracellular fluid by brief centrifugation and resuspended in Hanks' balanced salt solution. ESR examination showed that DEPMPO-OOH adducts were present in both fractions. When cells were stimulated by phorbol myristate acetate (PMA), the DEPMPO-OOH was detected in extracellular fluid but not in the cell fraction. Furthermore, DEPMPO-OOH adducts were quickly converted into ESR-silent compounds by addition of cell lysate of PMNs. These results indicate that DEPMPO is useful to detect O2*- of extracellular space including the intraphagosome but not that of intracellular space in sOZ-stimulated phagocytes.

IgA nephropathy with complement deficiency

We treated a female patient suffering from immunoglobulin A (IgA) nephropathy and congenital deficiency of the ninth component of the complement system (C9). She was admitted with hematuria and proteinuria, and the C9 deficiency was diagnosed based on the low hemolytic activity of 50 % of the hemolytic unit of the complements (CH50) and the normal C3 level in the plasma. Renal biopsy revealed mild mesangial proliferation, and immunofluorescence examination revealed mild mesangial deposits of IgA and C3 with the same distribution. We discuss the pathogenesis of IgA nephropathy and the role of the complements in its progression.

Clinical experiences of stenting in patients with esophago-bronchial fistula: report of four cases

The esophagorespiratory fistula is difficult to treat, and the patients' quality of life is generally poor due to suffering from dysphagia and dyspnea. We performed stent therapy in four cases of the esophagorespiratory fistula associated with esophageal cancer. Three of four patients showed improved symptoms, enabling oral liquid or food intake, although one died of dyspnea despite the therapy. The findings suggest that stent therapy is an effective method to close the esophagorespiratory fistula and to improve the patients' quality of life, although it is temporary and not a radical treatment.

FMLP-induced formation of F-actin in HL60 cells is dependent on PI3-K but not on intracellular Ca2+, PKC, ERK or p38 MAPK

OBJECTIVE AND DESIGN

To further understand the mechanisms of signal transduction pathways for the formation of F-actin (polymerization of actin) and the activation of NADPH oxidase in phagocytic cells, the effects of various inhibitors on them were studied.

MATERIALS AND METHODS

Differentiated HL60 cells were studied to examine their N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated formation of F-actin and activation of NADPH oxidase following treatment with various inhibitors. These included a protein kinase C (PKC) inhibitor (GF 109203X), a phosphatidylinositide 3 kinase (PI3-K) inhibitor (wortmannin), an extracellular response kinase (ERK) inhibitor (PD 98059), a p38 mitogen-activated protein kinase (MAPK) inhibitor (SB 203580) and an intracellular Ca2+ -chelator (BAPTA-AM).

RESULTS

The treatment with wortmannin suppressed the formation of F-actin, with less suppression of the activation of NADPH oxidase. BAPTA-AM and GF 109203X did not attenuate the formation of F-actin but completely inhibited the activation of NADPH oxidase. PD 98059 and SB 203580 partially inhibited the activation of NADPH oxidase without influence on the formation of F-actin. Furthermore, wortmannin but not BAPTA-AM and GF 109203X inhibited the fMLP-induced activation of Akt, which is known to regulate NADPH oxidase.

CONCLUSIONS

These results suggest that the formation of F-actin is dependent on PI3-K and independent of PKC, ERK and p38 MAPK as well as the increase in intracellular Ca2+, whereas the activation of NADPH oxidase is partly dependent on ERK, p38 MAPK, Akt regulated by PI3-K, and strongly dependent on the activation of PKC and the increase in intracellular Ca2+.

Unique response of double-stranded oligonucleotides containing a single 8-oxo-7,8-dihydroguanine to gamma rays in the frozen aqueous state at 77 K

Two kinds of double-stranded oligonucleotides containing a single 8-oxo-7,8-dihydroguanine were labeled with (32)P at their 5' ends and exposed to gamma rays in the frozen aqueous state at 77 K, where both direct and quasi-direct effects of ionizing radiation predominate. Analysis of the oligonucleotides with 20% denaturing polyacrylamide gel electrophoresis revealed no difference in the immediate induction of strand breaks between oligonucleotides containing 8-oxo-7,8-dihydroguanine and their corresponding oligonucleotides with normal guanine, but piperidine-sensitive damage was induced more frequently in the former than in the latter. Sequence analysis of irradiated oligonucleotides showed that not only 8-oxo-7,8-dihydroguanine but also its neighboring bases and the cytosine residue that is paired to it became piperidine-sensitive in both oligonucleotides. These results suggest that 8-oxo-7,8-dihydroguanine, its neighboring bases and the opposite cytosine are candidates for radiation damage hot spots.