Single minimum incision endoscopic radical nephrectomy for renal tumors with preoperative virtual navigation using 3D-CT volume-rendering

<p>Abstract</p> <p>Background</p> <p>Single minimum incision endoscopic surgery (MIES) involves the use of a flexible high-definition laparoscope to facilitate open surgery. We reviewed our method of radical nephrectomy for renal tumors, which is single MIES combined with preoperative virtual surgery employing three-dimensional CT images reconstructed by the volume rendering method (3D-CT images) in order to safely and appropriately approach the renal hilar vessels. We also assessed the usefulness of 3D-CT images.</p> <p>Methods</p> <p>Radical nephrectomy was done by single MIES via the translumbar approach in 80 consecutive patients. We performed the initial 20 MIES nephrectomies without preoperative 3D-CT images and the subsequent 60 MIES nephrectomies with preoperative 3D-CT images for evaluation of the renal hilar vessels and the relation of each tumor to the surrounding structures. On the basis of the 3D information, preoperative virtual surgery was performed with a computer.</p> <p>Results</p> <p>Single MIES nephrectomy was successful in all patients. In the 60 patients who underwent 3D-CT, the number of renal arteries and veins corresponded exactly with the preoperative 3D-CT data (100% sensitivity and 100% specificity). These 60 nephrectomies were completed with a shorter operating time and smaller blood loss than the initial 20 nephrectomies.</p> <p>Conclusions</p> <p>Single MIES radical nephrectomy combined with 3D-CT and virtual surgery achieved a shorter operating time and less blood loss, possibly due to safer and easier handling of the renal hilar vessels.</p

Occupational risk factors for Parkinson's disease: a case-control study in Japan

<p>Abstract</p> <p>Background</p> <p>The evidence for associations between occupational factors and the risk of Parkinson's disease (PD) is inconsistent. We assessed the risk of PD associated with various occupational factors in Japan.</p> <p>Methods</p> <p>We examined 249 cases within 6 years of onset of PD. Control subjects were 369 inpatients and outpatients without neurodegenerative disease. Information on occupational factors was obtained from a self-administered questionnaire. Relative risks of PD were estimated using odds ratios (ORs) and 95% confidence intervals (CIs) based on logistic regression. Adjustments were made for gender, age, region of residence, educational level, and pack-years of smoking.</p> <p>Results</p> <p>Working in a professional or technical occupation tended to be inversely related to the risk of PD: adjusted OR was 0.59 (95% CI: 0.32-1.06, <it>P </it>= 0.08). According to a stratified analysis by gender, the decreased risk of PD for persons in professional or technical occupations was statistically significant only for men. Adjusted ORs for a professional or technical occupation among men and women were 0.22 (95% CI: 0.06-0.67) and 0.99 (0.47-2.07), respectively, and significant interaction was observed (<it>P </it>= 0.048 for homogeneity of OR). In contrast, risk estimates for protective service occupations and transport or communications were increased, although the results were not statistically significant: adjusted ORs were 2.73 (95% CI: 0.56-14.86) and 1.74 (95% CI: 0.65-4.74), respectively. No statistical significance was seen in data concerning exposure to occupational agents and the risk of PD, although roughly a 2-fold increase in OR was observed for workers exposed to stone or sand.</p> <p>Conclusion</p> <p>The results of our study suggest that occupational factors do not play a substantial etiologic role in this population. However, among men, professional or technical occupations may decrease the risk of PD.</p

The 2G allele of promoter region of Matrix metalloproteinase-1 as an essential pre-condition for the early onset of oral squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Matrix metalloproteinase (<it>MMP</it>) is known to be involved in the initial and progressive stages of cancer development, and in the aggressive phenotypes of cancer. This study examines the association of single nucleotide polymorphisms in promoter regions of <it>MMP-1 </it>and <it>MMP-3 </it>with susceptibility to oral squamous cell carcinoma (OSCC).</p> <p>Methods</p> <p>We compared 170 Japanese OSCC cases and 164 healthy controls for genotypes of <it>MMP-1 </it>and <it>MMP-3</it>.</p> <p>Results</p> <p>The frequency of the <it>MMP-1 </it>2G allele was higher and that of the 1G homozygote was lower in the OSCC cases (<it>p </it>= 0.034). A multivariate logistic regression analysis revealed that subjects who were 45 years old or older had a significantly increased (2.47-fold) risk of OSCC (95%CI 1.47–4.14, <it>p </it>= 0.0006), and those carrying the <it>MMP-1 </it>2G allele had a 2.30-fold risk (95%CI 1.15–4.58, <it>p </it>= 0.018), indicating independent involvement of these factors in OSCC. One of the key discoveries of this research is the apparent reduction of the <it>MMP-1 </it>1G/1G and 1G/2G genotype distributions among the early onset OSCC cases under the ages of 45 years. It should be noted that the tongue was the primary site in 86.2% of these early onset cases. This could suggest the specific carcinogenic mechanisms, i.e. specific carcinogenic stimulations and/or genetic factors in the tongue.</p> <p>Conclusion</p> <p>Since the 2G allele is a majority of the <it>MMP-1 </it>genotype in the general population, it seems to act as a genetic pre-condition in OSCC development. However this report suggests a crucial impact of the <it>MMP-1 </it>2G allele in the early onset OSCC.</p

Metformin efficacy and safety for colorectal polyps: a double-blind randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Colorectal cancer is one of the major neoplasms and a leading cause of cancer death worldwide, and new preventive strategies are needed to lower the burden of this disease. Metformin, a biguanide, which is widely used for treating diabetes mellitus, has recently been suggestive to have a suppressive effect on tumorigenesis and cancer cell growth. In a previous study conducted in non-diabetic subjects, we showed that oral short-term low-dose metformin suppressed the development of colorectal aberrant crypt foci (ACF). ACF have been considered as a useful surrogate biomarker of CRC, although the biological significance of these lesions remains controversial. We devised a prospective randomized controlled trial to evaluate the chemopreventive effect of metformin against metachronous colorectal polyps and the safety of this drug in non-diabetic post-polypectomy patients.</p> <p>Methods/Design</p> <p>This study is a multi-center, double-blind, placebo-controlled, randomized controlled trial to be conducted in non-diabetic patients with a recent history of undergoing colorectal polypectomy. All adult patients visiting the Yokohama City University hospital or affiliated hospitals for polypectomy shall be recruited for the study. Eligible patients will then be allocated randomly into either one of two groups: the metformin group and the placebo group. Patients in the metformin group shall receive oral metformin at 250 mg per day, and those in the placebo group shall receive an oral placebo tablet. At the end of 1 year of administration of metformin/placebo, colonoscopy will be performed to evaluate the polyp formation.</p> <p>Discussion</p> <p>This is the first study proposed to explore the effect of metformin against colorectal polyp formation. Metformin activates AMPK, which inhibits the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway plays an important role in the cellular protein translational machinery and cell proliferation. Patients with type 2 diabetes taking under treatment with metformin have been reported to be at a lower risk of cancer development than those not taking under treatment with metformin. We showed in a previous study that metformin suppressed the formation of human colorectal ACF. We therefore decided to conduct a study to determine whether metformin might suppress the formation of human colorectal polyps.</p> <p>Trial registration</p> <p>This trial has been registered in the University hospital Medical Information Network (UMIN) Clinical Trials Registry as <a href="http://www.clinicaltrials.gov/ct2/show/UMIN000006254">UMIN000006254</a></p

Pathophysiology of flow impairment during carotid artery stenting with an embolus protection filter

Objective: Carotid artery stenting (CAS) is a well-accepted treatment for atherosclerotic stenosis of carotid arteries. Since the occurrence of distal embolization with CAS is still a major concern embolus protection devices (EPD) are usually employed during the procedure. We examined two types of embolus protection filters (Angioguard XP (AG); Filterwire EZ (FW)) and evaluated the function. Thus, the filter was examined postoperatively and the cause of intraoperative flow impairment was evaluated. Materials and methods: CAS was performed for 54 patients with carotid artery stenosis (55 lesions: 25 AG; 27 FW; 3 others). After completing CAS the filter membrane was stained with hematoxylin-eosin (HE) solution and removed from the filter strut. Once mounted on a glass slide the filter was evaluated under a microscope. The area occupied with debris was measured and the relationship to intraoperative flow impairment was evaluated. Furthermore, the relationship between perioperative ischemic complications and intraoperative flow impairment was statistically analyzed. Results: Microscopic observation of the slide revealed the pore density of the FW was 1.5 times higher than that of the AG and the filter area of the FW was 2.5 times wider than than the AG. HE staining facilitated characterization of the debris composition. The area occupied with debris was significantly more in the AG (0.241 ±0.13 cm2) than in the FW (0.129 ±0.093 cm2). Thus, fibrin was significantly more precipitated in the AG. Flow impairment occurred in 6 AG cases (24.0 %) and 4 FW cases (14.8 %). It was induced by filter obstruction in the AG and by vasospasms in the FW. Three cases treated with AG (12.0 %) were complicated with cerebral infarction and all of them were related to flow impairment. One FW case (3.7 %) was complicated with cerebral infarction in presence of preserved flow throughout the intervention. Conclusion: Filter function is different according to each design. The cause of flow impairment was attributable to filter obstruction in the AG group and to vasospasms in the FW group. Filter obstruction tends to result in cerebral infarction