A Paced Auditory Serial Addition Task evokes stress and differential effects on masseter-muscle activity and haemodynamics

This study aimed to determine autonomic and jaw-muscle activities, and haemodynamic responses, to acute experimental mental stress in humans. Eleven healthy men (25.2 ± 3.0 years of age) and five healthy women (23.0 ± 3.7 years of age) performed a standardized mental stress task, the Paced Auditory Serial Addition Task (PASAT). Autonomic function, such as heart rate variability (HRV), and haemodynamic changes were recorded simultaneously. The success rate of the PASAT decreased with increased pace and duration. Low-frequency (5.8 ± 1.1 ms(2)) and high-frequency (5.3 ± 0.6 ms(2)) components of HRV decreased during the PASAT (to 5.0 ± 0.9 ms(2) and 4.6 ± 1.1 ms(2), respectively) as an indication of acute stress. Oxygenated haemoglobin in the masseter muscle (14.6 ± 2.2 10(4) units mm(-3)) remained at an elevated level during the PASAT (15.5 ± 2.5 10(4) units mm(-3)), whereas deoxygenated haemoglobin (7.8 ± 2.3 10(4) units mm(-3)) showed a consistent decrease (to 6.8 ± 2.1 10(4) units mm(-3)). Total haemoglobin and jaw-muscle electromyographic (EMG) activity did not change during the PASAT. Thus, PASAT-induced mental stress changed the parasympathetic/sympathetic balance of the heart and had an acute influence on jaw-muscle haemodynamics, but not on jaw-muscle EMG activity. This non-invasive experimental set-up can be applied to study the effects of repeated or longer-lasting mental stress in order to further the understanding of pathophysiological mechanisms in craniofacial pain conditions.     

Association Between Glucan Synthesis by Streptococcus mutans and Caries Incidence in Schoolchildren Receiving a Fluoride Mouth Rinse

Purpose: To determine whether variation in glucan synthesis by Streptococcus mutans isolates is associated with caries development in children receiving a fluoride mouth rinse (FMR). Materials and Methods: Of 122 children (aged 9 to 10 years), 64 had received FMR (FMR(+) group) and the remaining 58 children had not (FMR(-) group). The number of decayed and filled teeth (DFT) and increases in the number of DFT in 1 year (dDFT) were recorded. Saliva samples were collected to isolate the clinical S. mutans strains. The isolates were incubated in heart infusion broth supplemented with 1% sucrose, then the amount of water-insoluble glucan (WIG) formed on a glass tube surface was evaluated. Results: In the FMR(-) group, children carrying S. mutans had a higher DFT (P = 0.039) and tended to have a higher dDFT (P = 0.080) than the others. In the FMR(+) group, although the differences between children with and without S. mutans were not significant, children carrying S. mutans that produced a high amount of WIG had higher dDFT than the other S. mutans-positive children (P = 0.034). Conclusions: This study revealed that the variation in glucan synthesis by S. mutans is associated with caries development in children receiving a FMR.     

Intrahepatic cholangiojejunostomy (Longmire procedure) for recurrent bilioenteric anastomotic stricture with hepatolithiasis

Interventional procedure via percutaneous transhepatic route is often performed, as an initial treatment, in patients with benign bilioenteric anastomotic stricture. However, surgical management is required in most cases in which radiological intervention is unsuccessful. In this report, we describe a case of a 67-year-old woman with recurrent bilioenteric anastomotic stricture, accompanying bilateral hepatolitiasis after several times of transhepatic interventions. The patient underwent intrahepatic cholangiojejunostomy (Longmire procedure) and cholangioscopic lithotomy after resection of an atrophic left lateral segment resulting from hepatolithiasis. Although the damaged hilar bile duct had to be isolated and divided from the corresponding vasculature for re-anastomosis, it was quite impossible due to severe inflammatory change at the hepatic hilus. We, therefore, anastomosed the intact biliary stump on the cut surface of the left lateral segment to the jejunal loop with a stent tube. The patient's postoperative course was uneventful and she exhibited no evidence of cholangitis during follow-up period of 1 year after surgery. At present, the indications for intrahepatic cholangiojejunostomy for biliary obstruction, are quite limited, but biliary surgeons should keep this procedure in mind at the time of biliary reconstruction for benign proximal bile duct stricture, particularly in cases of multiply operated hilum.     

Clinical evaluation of peginterferon α plus ribavirin for patients co-infected with HIV and HCV at Nagoya Medical Center

At Nagoya Medical Center, 10 patients co-infected with HIV and HCV received peginterferon α (PEG-IFNα) plus ribavirin therapy. Three of the cases were HCV genotype 1b, 2 cases were HCV 3b, and 1 case each were 2b, 2c, 3a, 4a and 6n. Nine patients received anti HIV therapy from the beginning. In 5 of these patients, anti HIV therapy was modified when PEG-IFNα plus ribavirin treatment was started. Of the above, 7 patients completed the protocol. No patients had severe adverse effects. Sustained virological response was achieved in 1 of 4 (25%) of the patients with genotypes 1 or 4, and in 5 of 6 (83%) of the patients with other genotypes. PEG-IFNα plus ribavirin therapy is considered a safe and efficacious treatment for patients co-infected with HIV and HCV.     

Preliminary evaluation of insecticide-impregnated ceiling nets with coarse mesh size as a barrier against the invasion of malaria vectors

We evaluated the effectiveness of installing the Olyset? Net on the ceiling in preventing the invasion of malaria vectors. This study was conducted in houses in western Kenya. The number of resting mosquitoes inside the houses reduced when the ceiling and eaves of the houses were covered with the net. The mosquito densities remained low for 9 months, until the nets were removed.