Electroacupuncture ameliorates spatial learning and memory impairment via attenuating NOX2-related oxidative stress in a rat model of Alzheimer's disease induced by Aß1-42.

Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by progressive deterioration of cognition and memory, in which oxidative stress has been played a crucial role in the pathology of AD. Electroacupuncture (EA) is a widely used therapy based on traditional acupuncture combined with modern electrotherapy in Asia. The present study aimed to determine the effects of EA treatment on spatial learning and memory impairment, and to elucidate the status of NOX2-related oxidative stress in a rat model of Alzheimer's disease induced by Beta-amyloid1-42 (Aß1-42). Fifty-six adult female Sprague-Dawley (SD) rats were randomly divided into four groups: sham, sham+EA, AD and AD+EA. The rats in Sham+EA and AD+EA groups were respectively administrated EA treatment at Baihui and yongquan acupoints, once a day for 30 min, lasting for 28 days. The spatial learning and memory functions were assessed by Morris water maze (MWM) test. The activities of total antioxidant capacity (T-AOC), reactive oxygen species (ROS), malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OH-dG) were evaluated. Moreover, the neuronal injury was detected by Nissl staining. Meanwhile, the NeuN expression was examined in the hippocampus, the expression levels of Nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase2(NOX2) was detected by immunofluorescence staining and western blot. The results showed that EA treatment significantly improved spatial learning and memory impairment in rats induced by Aß1-42. Concomitantly, EA treatment markedly restored T-AOC and attenuated the abnormal increase in levels of ROS, MDA and 8-OH-dG in the hippocampus of the AD rats. More notably, EA treatment also effectively ameliorated neuronal injury and counteracted the aberrant increase of NOX2 levels in the hippocampus of AD rats. Our findings suggested that EA is a potential strategy for the treatment of AD, and the possible mechanism is associated with the alleviation of neuronal injury and inhibition of NOX2-related oxidative stress.

Interventions for relieving pain associated with panretinal photocoagulation: a prospective randomized trial.

PURPOSE: To evaluate the efficacy of pain relief by oral diazepam, acetaminophen, mefenamic acid, intramuscular ketorolac tromethamine, and peribulbar anaesthesia in panretinal photocoagulation (PRP). METHODS: A total of 220 patients with proliferative diabetic retinopathy requiring PRP treatment were enrolled in this study. Before laser treatment, the patients were allocated randomly to one of eight groups: group 1: diazepam (n=22), group 2: acetaminophen (n=21), group 3: mefenamic acid (n=21), group 4: diazepam and acetaminophen (n=22), group 5: diazepam and mefenamic acid (n=22), group 6: peribulbar anaesthesia with lidocaine (n=23), group 7: intramuscular injection of ketorolac tromethamine (n=22), group 8: placebo (n=67). Pain after the laser treatment was assessed by a verbal descriptive scale. Blood pressure and heart rate were measured before and after laser treatment. RESULTS: Patients receiving peribulbar anaesthesia had a significantly lower pain score than the control group (P<0.0001). Additionally, the peribulbar anaesthesia-treated group had the significantly least PRP-associated rise in either systolic (P=0.043) or diastolic blood pressure rates (P=0.030). There were no significant differences in pain score using other anesthetic agents when compared with the control group. There were no significant changes in heart rate after PRP treatment. CONCLUSION: Peribulbar anaesthesia is effective in reducing pain and blood pressure increase after PRP treatment. Oral diazepam, mefenamic acid, and acetaminophen (either alone or in combination with each other) are not effective in preventing PRP treatment-associated pain. Intramuscular injection of ketorolac tromethamine is also not effective in reducing PRP-associated pain.

Nitric oxide reduces blood pressure in the nucleus tractus solitarius: a real time electrochemical study.

Increasing evidence has demonstrated that nitric oxide (NO) is involved in central cardiovascular regulation. In this study, we directly measured extracellular NO levels, in real-time, in the nucleus tractus solitarius (NTS) of anesthetized cats using Nafion/Porphyrine/o-Phenylenediamine-coated NO sensors. We found that local application of L-arginine (L-Arg) induced NO overflow in NTS and hypotension. These responses were potentiated in the vagotomized animals. Pretreatment with NO synthase (NOS)/guanylate cyclase inhibitor methylene blue, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one or NO scavenger hemoglobin attenuated L-Arg-induced hypotension, suggesting that exogenous supplement of NO suppressed cardiac functions through the NOS/cyclic guanosine monophosphate mechanism. The role of endogenous NO was examined after local application of N(G)-nitro-L-arginine methyl ester (L-NAME). We found that L-NAME suppressed endogenous NO levels in NTS and elicited hypertension and tachycardia. Taken together, our data suggest that NO is tonically released in the NTS to inhibit blood pressure.

Positive predictive value and posttest probability of diagnosis of colonic polyp on single- and double-contrast barium enema.

The positive predictive value for a radiographic diagnosis of colonic polyp, the prevalence of polypoid disease, and posttest probability relative to patient age were studied. The positive predictive value for colonic polyp on single- and double-contrast barium enema was determined for 191 polyps found radiographically in 136 patients who also underwent colonoscopy for confirmation. Of 72 polyps seen in 54 patients on single-contrast examination, 59 were confirmed endoscopically; 110 of 119 polyps seen in 82 patients on double-contrast examination were confirmed similarly, giving positive predictive values of 82% and 92%, respectively. Positive predictive values per patient, disregarding the number of polyps present, were 87% (47/54) and 90% (74/82) for the single- and double-contrast examinations, respectively. False-positive errors were due to stool, air bubbles, haustration, and misinterpretation of an appendiceal stump. By using specificities derived from our prevalence of polypoid disease and previously reported sensitivities, we drew posttest probability curves showing that predictive values depend both on the chance of disease before the test is done and on the efficacy of the test used.

Barium enema examination: sensitivity in detecting colonic polyps and carcinomas.

We analyzed the sensitivity of the barium enema examination in 128 patients with 191 endoscopically proven colonic polyps and 12 carcinomas, relative to patient age, indications, and the type of examination used. Seventy-seven patients (60%) had rectal bleeding, and 51 (40%) patients with 87 lesions, including six carcinomas, did not. Overall roentgenographic sensitivity was 88%, with a 93% detection rate in patients less than 70 years old as compared to 76% for older patients. Sensitivity of single- and double-contrast barium enema examination was 82% and 91%, respectively. There were similar detection rates for lesions 1 cm or more in size (91% vs 95% for single- and double-contrast examinations, respectively), but double-contrast examination was slightly better at detecting smaller polyps (88%, vs 70% for single-contrast examination). Compared to colonoscopy, which has an average reported false-negative rate of 12% in detecting neoplasms, the barium enema is similarly reliable, less costly, and safer.

Radiographic magnification of colon polyps.

Radiographic magnification was evaluated on conventional and remote control machinery using a phantom with steel rods positioned at different levels. Depending on the rod-film distance, the range of magnification was 8-47% on remote control and conventional overhead films and 11-82% on conventional fluoroscopic spot-films. Extrapolation to the colon based on cross-sectional anatomic correlation showed a 14-27% variation in the radiographic magnification depending on the machinery used, the segment of the colon considered, and the position of the patient. This implies that substantial inaccuracy in the measurement of colonic polyps is common by barium enema examination, particularly when a conventional fluoroscope is used.

Single-contrast vs double-contrast barium enema in the detection of colonic polyps.

Radiographic and colonoscopic correlation in 139 patients with 234 colonic polyps compared the sensitivity of single- and double-contrast barium enema. Single-contrast barium enema detected 68 (80%) of polyps, with 72% of polyps under 1 cm and 94% of those 1 cm or over detected. Double-contrast barium enema detected 135 (91%) of 149 polyps, with 88% of polyps under 1 cm and 96% of larger polyps detected. Thus, the double-contrast barium enema was more effective than the single-contrast examination only for detection of polyps under 1 cm. The single-contrast barium enema was more likely performed on patients in poor physical condition and in those over 70 years old. The results suggest that for elderly patients, who may have difficulty in cooperating for a double-contrast enema, a properly performed single-contrast examination is an acceptable option.

The extent of successful colonoscopy: a second assessment using modern equipment.

Records of 200 consecutive and unselected colonoscopies were reviewed to determine both the success in viewing the entire colon and the average extent of colon visualized, using the most modern equipment. Colonoscopy was completed to the cecum or ileum in 82.5% of studies, and an average of 93.8% of the colon was viewed. These data show considerable improvement compared to those previously reported by us. However, the significant number of incomplete colonoscopies still suggests that colonoscopy and barium enema examination must remain complementary for maximum detection of colonic lesions.

Colon polyp morphology on double-contrast barium enema: its pathologic predictive value.

The morphologic appearance of 96 polyps seen on double-contrast barium enema was reviewed to assess the predictive value of various signs described to diagnose malignancy. Size, surface contour, basal indentation, and pedunculation were studied. Sessile polyps had an appreciable incidence of malignancy, with size being the best indicator of that risk. Pedunculation was found to be a reliable sign of benignity in predicting the absence of malignant invasion into the adjacent colonic wall. Polyps under 1 cm and having a smooth contour were invariably benign. Conversely, polyps larger than 1 cm with a lobulated contour and basal indentation had a significant incidence of malignancy.

The gravitational field and brain function.

The frontal cortex is recognized as the highest adaptive control center of the human brain. The principle of the "frontalization" of human brain function offers new possibilities for brain research in space. There is evolutionary and experimental evidence indicating the validity of the principle, including it's role in nervous response to gravitational stimulation. The gravitational field is considered here as one of the more constant and comprehensive factors acting on brain evolution, which has undergone some successive crucial steps: "encephalization", "corticalization", "lateralization" and "frontalization". The dominating effects of electrical responses from the frontal cortex have been discovered 1) in experiments under gravitational stimulus; and 2) in processes potentially relating to gravitational adaptation, such as memory and learning, sensory information processing, motor programing, and brain state control. A brain research experiment during space flight is suggested to test the role of the frontal cortex in space adaptation and it's potentiality in brain control.

Extent of colonic visualization with the fiberoptic sigmoidoscope.

Forty-two patients underwent flexible sigmoidoscopy in the radiology department. After maximal insertion of the sigmoidoscope, a supine abdominal film documented the position of the tip of the instrument. Correlation with barium enema in all patients determined the extent of visualization of the colon relative to the length of insertion of the sigmoidoscope. Insertion to 60 cm was achieved in 31 (74%), 40-59 cm in six (14%), 25-39 cm in three (7%), and under 25 cm in two (5%), with a mean depth of insertion of 54 cm. Full insertion examined the entire sigmoid colon in 14 (45%) of 31 patients. Insertion between 40-59 cm achieved complete sigmoid evaluation in only one (17%) of six patients. Thus, flexible sigmoidoscopy does not necessarily guarantee evaluation of the entire sigmoid colon.

Sensitivity of double-contrast barium enema: emphasis on polyp detection.

Colonoscopically verified lesions (230 in 178 patients) were reviewed and compared to results of double-contrast barium enema studies performed by radiologists specifically interested in gastrointestinal disease. Eighteen carcinomas and 22 cases of colitis found endoscopically were accurately identified radiographically. In 140 patients with 190 polyps, 16 lesions were missed radiologically, a false-negative error for polyps of 8.4%. All undetected polyps were distal to the splenic flexure with the majority located in the sigmoid colon. Thus, the double-contrast barium enema study was quite effective in finding colon polyps, particularly proximal to the splenic flexure.

The extent of successful colonscopy: its implication for the radiologist.

Records of 230 colonoscopies were reviewed to determine the success in viewing the entire colon and the extent of the colon viewed when colonoscopy was incomplete. It was found that colonoscopy was complete to the cecum or ileum in 57% of studies, and that an average 63.8% of the colon was viewed during incomplete studies. Overall, 84.4% of the combined length of all colons examined was successfully viewed. The significant numbers of incomplete colonoscopies suggest that colonoscopy and the barium enema examination must remain complementary for maximum detection of colon lesions.