Oxidative DNA damage in relation to neurotoxicity in the brain of mice exposed to arsenic at environmentally relevant levels

To clarify the association between oxidative DNA damage and the neurotoxicity of arsenic, the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an index of oxidative DNA damage in the brain was examined in mice fed with drinking water containing 1 or 2 ppm arsenic, using an HPLC-electrochemical detector and immunohistochemical method. 8-OHdG levels were significantly increased in the brain of mice given arsenic and its immunoreactivity was distributed in the cerebral and cerebellar cortexes. Cerebral cortex neurons and Purkinje cells in the cerebellar cortex showed degenerative changes in accordance with the distribution of 8-OHdG immunoreactivity. The levels of arsenic in this study were lower than those reported in epidemiological studies. Thus, we conclude that environmentally relevant levels of arsenic induce pathological changes through oxidative DNA damage in the brain tissues in vivo and that cerebral and cerebellar cortex neurons seem to be the major targets of arsenic neurotoxicity.     

Correlation between suspended particles in the environmental air and causes of disease among inhabitants: cross-sectional studies using the vital statistics and air pollution data in Japan

To identify the diseases that correlate with suspended particle concentration in the ambient air, a cross-sectional epidemiological study was conducted using the annual vital statistics and air pollution estimates of 1881 points throughout Japan. The concentration of suspended particulate matters (SPMs) 10 microm or less in diameter were hypothetically converted to PM(2.5) values (converted PM(2.5) or cPM(2.5)) by using a conversion factor obtained from 25 estimates in Japan. Among various causes of death, a significant correlation was observed between both the SPM and cPM(2.5) (SPM/cPM(2.5)) levels and the age-adjusted death rates of ischemic heart disease or hypertensive heart disease in both genders. Correlation was noted with pneumonia, asthma, chronic bronchitis/emphysema, or lung cancer only in females. Unexpectedly, breast, endometrial, and ovarian cancer also showed significant increases in mortality rates related to the SPM/cPM(2.5) level, suggesting a role for suspended particles in the ambient air with or without gaseous component as a possible endocrine-disrupting, estrogenic agent. Multivariate regression analysis of confounding factors, smoking rate, population density, and hormone-related factors revealed consistent significance of SPM/cPM(2.5) in these diseases.     

Current antibiotic prophylaxis in pancreatoduodenectomy in Japan

Background/Purpose The aim of this study was to investigate the current use of antibiotic prophylaxis (AP) in association with pancreatoduodenectomy (PD) in Japan, and to determine its surgical implications.Methods We surveyed 2331 patients who underwent PD for treatment of disease in the periampullary region. Data, obtained during the period January 2002 through December 2003, from 111 major surgical services associated with the Japanese Society for Pancreatic Surgery, were analyzed with regard to patient characteristics, preoperative complications, AP, and postoperative morbidities.Results Eighty-five (78.7%) of the 108 eligible institutions chose a first- or second-generation cephalosporin for AP, given for a mean duration of 4.3 days. At all but 1 institution, the first dose was administered prior to surgical incision of the skin. At 42% of the institutions, an additional antibiotic was administered during surgery. The overall rate of wound infection was 6.8% of the 2266 patients for whom data were available. Preoperative jaundice was found in 55.3% of these 2266 patients, and 92.6% of these jaundiced patients were suffering from preoperative infections. In addition, those with preoperative infections were also diagnosed as having biliary infections. The number of patients with preoperative jaundice in combination with preoperative infections was significantly related to the rate of postoperative morbidity (P < 0.0001).Conclusions Administration of AP in association with PD in Japan seems appropriate. Icteric patients with biliary infections are at high risk for postoperative morbidities and need careful monitoring after surgery.A summary of this survey was presented, in part, at the 31st Annual Meeting of the Japanese Society for Pancreatic Surgery, May 2004, Osaka, Japan     

Contribution of CD4+ and CD8+ T cells and interferon-gamma to the progress of chronic rejection of kidney allografts: the Th1 response mediates both acute and chronic rejection

T cells mediating chronic rejection (CR) of human kidney allografts were characterized by comparing them with those mediating acute rejection (AR). Two lines of analysis were performed using biopsy specimens (23 CR and 8 AR). First, the extent of infiltration of CD4+ and CD8+ T cells into allografts was assessed from mRNA expression of CD4 and CD8. The group of CR specimens was not significantly different from the group of AR specimens in terms of the extent of CD4+ and CD8+ T cell infiltration, underlining the importance of the immunological contribution to the progress of CR. Second, Th1/Th2 polarization in infiltrating T cells was investigated by measuring mRNA expression of interferon gamma (IFN-gamma; a Th1 cytokine) and interleukin 4 (IL-4; a Th2 cytokine). IFN-gamma expression was detected in most CR specimens, and was not significantly different between the group of CR specimens and the group of AR specimens. On the other hand, IL-4 expression was detected in only two CR specimens and one AR specimen; from its pathological features, the AR in this last case was concomitant with CR. These results suggest that most cases of CR and of AR are mediated by Th1 mechanisms, although some cases of CR show features of both Th1 and Th2.     

Renoprotective properties of angiotensin receptor blockers beyond blood pressure lowering

Clinical studies have demonstrated that some antihypertensive agents provide renoprotection independent of BP lowering. Recent in vitro and in vivo studies evaluated the mechanisms involved in this protection. First, the in vitro effects of several angiotensin II type 1 receptor blockers (ARB), calcium channel blockers (CCB), and beta blockers (BB) on various mediators were compared: Formation of pentosidine (an advanced glycation end product), hydroxyl radical-induced formation of o-tyrosine, and transition metals-induced oxidation of ascorbic acid (the Fenton reaction). All of the six tested ARB but neither the six CCB nor the nine BB inhibited pentosidine formation. ARB, as well as BB but not CCB, inhibited hydroxyl radicals-mediated o-tyrosine formation. ARB but neither BB nor CCB inhibited efficiently transition metals-catalyzed oxidation of ascorbic acid. Second, the in vivo consequences for the kidney of these various in vitro effects were evaluated. Hypertensive, type 2 diabetic rats with nephropathy, SHR/NDmcr-cp, were given for 20 wk either olmesartan (ARB) or nifedipine (CCB), or atenolol (BB). Despite similar BP reduction, only ARB significantly reduced proteinuria and prevented glomerular and tubulointerstitial damage (mesangial activation, podocyte injury, tubulointerstitial injury, and inflammatory cell infiltration). It is interesting that only ARB prevented abnormal iron deposition in the interstitium, corrected chronic hypoxia, reduced expressions of heme oxygenase and p47phox (a subunit of NADPHoxidase), and inhibited pentosidine formation (which correlates well with proteinuria). These observations confirm unique renoprotective properties of ARB, independent of BP lowering but related to decreased oxidative stress (hydroxyl radicals scavenging and inhibition of the Fenton reaction), correction of chronic hypoxia, and inhibition of advanced glycation end product formation and of abnormal iron deposition. These benefits of ARB may contribute to the renoprotection observed beyond BP lowering.     

Opposing effects of isoflurane and sevoflurane on neurogenic pulmonary edema development in an animal model

BACKGROUND: The current study was undertaken to investigate the effects of pretreatment with isoflurane and sevoflurane on the development of neurogenic pulmonary edema in an animal model. METHODS: Rats were exposed to room air (control), 1.5% isoflurane, or 2.5% sevoflurane for 4 h. They were then anesthetized with intraperitoneal injections of pentobarbital sodium, and fibrinogen and thrombin were injected into the cisterna magna to induce neurogenic pulmonary edema. RESULTS: Consecutive injections of fibrinogen and thrombin caused increases in blood pressure, with the peak values obtained in the isoflurane and sevoflurane groups being lower than the control values. The incidence of significant neurogenic pulmonary edema was 58%, 100%, and 8% in the control, isoflurane, and sevoflurane groups, respectively. The lung water ratio, an index of severity of edema, was 4.86 +/- 0.78, 6.15 +/- 0.64, and 4.40 +/- 0.32 in the control, isoflurane, and sevoflurane groups, respectively. Furthermore, immunohistochemical staining for vascular endothelial growth factor demonstrated an increase of expression in the rat lungs exposed to isoflurane. Treatment with an anti-vascular endothelial growth factor antibody during exposure to isoflurane completely inhibited the effect of isoflurane to promote neurogenic pulmonary edema in this model. CONCLUSION: Exposure to 1.5% isoflurane enhances the development of neurogenic pulmonary edema development in this animal model, most likely via release of vascular endothelial growth factor from bronchial epithelial cells, an effect not observed with sevoflurane.     

A comparison of teledermatology using store-and-forward methodology alone, and in combination with Web camera videoconferencing

We compared the diagnostic accuracy of conventional asynchronous teledermatology ('store-and-forward' [SAF]) with a combined technique, in which SAF methodology was used first, followed by a videoconference using low-cost Web cameras. The study involved 228 patients with 242 lesions. For each case, two independent teledermatologists (A and B) evaluated digital images and clinical information by the conventional SAF method and gave a single diagnosis. Then, each communicated with the patient via Web cameras and gave a single diagnosis (combined method). Finally, teledermatologist A performed a face-to-face examination of each patient and established the gold standard diagnosis. With the conventional SAF method, the diagnostic accuracy of teledermatologist A was 81%, while that for teledermatologist B was 75%. With the combined method, the corresponding values were 90% and 82% (P<0.001 for both). There was no significant difference in the interobserver agreement between the two methods. Use of Web camera videoconferencing improved patient satisfaction with teledermatology. This method of teledermatology may be a useful alternative to the SAF method alone.     

Absorption, metabolism, degradation and urinary excretion of rosmarinic acid after intake of Perilla frutescens extract in humans

Summary Background Rosmarinic acid (RA) is a natural polyphenolic substance contained in many Lamiaceae herbs such as Perilla frutescens. Previous studies have shown RA has antioxidative and anti-inflammatory activity. However, little is known on the absorption, metabolism, degradation and excretion of RA. Aim of the study The aim of this study in healthy humans was to determine the absorption, metabolism, and urinary excretion of RA after a single intake of perilla extract (PE). Method Six healthy men (mean age 37.2 ± 6.2 y and mean body mass index 22.0 ± 1.9 kg/m²) were enrolled in the study that was a crossover design involving single intakes of PE containing 200 mg RA and placebo with a 10 day interval between treatments. Blood samples were collected before intake and at designated time intervals, while urine samples were collected over the periods 0-6 h, 6-24 h and 24-48 h after intake. RA and its related metabolites in plasma and urine were measured by LC-MS. Results RA, methylated RA (methyl-RA), caffeic acid (CAA), ferulic acid (FA) and a trace of m-coumaric acid (COA) were detected in the urine after intake of PE. In plasma, RA, methyl-RA and FA were detected, with maximum levels obtained 0.5, 2 and 0.5 h after intake of PE, respectively. The majority of these components in both plasma and urine were present as conjugated forms (glucuronide and/or sulfated). The proportion of RA and its related metabolites excreted in the urine was 6.3 ± 2.2% of the total dose,with approximately 75% of these components being excreted within 6h after intake of PE. Conclusions RA contained in PE was absorbed, conjugated and methylated following intake,with a small proportion of RA being degraded into various components, such as conjugated forms of CAA, FA and COA. These metabolites were then rapidly excreted in the urine.An erratum to this article can be found at