Electron inelastic mean free path formula and CSDA-range calculation in biological compounds for low and intermediate energies.

In this study, for low atomic number targets and biological compounds, an inelastic mean free path (IMFP) formula and energy straggling parameter formula are presented, being valid for low and high electron energies. In addition, calculation of the continuous slowing down approximation-range (CSDA-range) from the stopping power is also made. The IMFP and the energy straggling parameter formulae are evaluated using the generalized oscillator strength (GOS) model and the exchange correction to the inelastic differential cross section (IDCS) given by Inokuti, M., [1978. Inelastic collisions of fast charged particles with atoms and molecules--the Bethe theory revisited. Rev. Mod. Phys. 50, 23-35]. The IMFP and CSDA-range for the biological compounds C5H5N5 (adenine), C5H5N5O (guanine), C4H5N3O (cytosine), C5H6N2O2 (thymine), C20H27N7O13P2 (cytosine-guanine) and C19H26N8O13P2 (thymine-adenine) have been introduced for incident electrons in the energy range 20 eV-1 MeV. The calculated results are compared with semi-empirical results and other theoretical results, good agreement being found with experimental data and Monte Carlo (PENELOPE code) predictions. All the IMFP versus energy curves exhibit minima around 80 eV.     

Prolonged exclusive breastfeeding is associated with increased atopic dermatitis: a prospective follow-up study of unselected healthy newborns from birth to age 20 years

BACKGROUND: Exclusive breastfeeding for the first 6 months is recommended by the World Health Organization and considered allergy preventive. However, it is not known whether prolonging exclusive breastfeeding for over 6 months provides further benefit in allergy prevention. OBJECTIVE: The aim of this prospective 20-year follow-up study was to find out whether the allergy protective effect can be enhanced by prolonging strictly exclusive breastfeeding for > or =9 months of age. A total of 200 unselected healthy newborns were enrolled in the study. Their mothers were encouraged to maintain exclusive breastfeeding for as long as possible. The number of infants on strictly exclusive breastfeeding was 167 at 2, 116 at 6, 36 at 9 and 7 at 12 months of age. Of the 200 infants, 42% had a family history of allergy. The children were re-assessed at ages 5 (n=163), 11 (n=150) and 20 years (n=164) with clinical examination, skin prick testing, and parental and personal structured interviews. RESULTS: Exclusive breastfeeding prolonged for > or =9 months was associated with atopic dermatitis (P=0.002) and symptoms of food hypersensitivity (P=0.02) at age 5 years, and with symptoms of food hypersensitivity at age 11 years (P=0.01), in children with a family history of allergy. CONCLUSION: Prolonging strictly exclusive breastfeeding for > or =9 months was not helpful in atopy prevention, instead, it was associated with increased atopic dermatitis and food hypersensitivity symptoms in childhood.     

A randomised trial of ultrasonic dissection versus electrocoagulation to reduce lymphatic complications after surgery for recurrent sapheno-femoral incompetence.

OBJECTIVE: Prospectively to compare lymphatic drainage after ultrasonic dissection, an electrocoagulation technique and sharp dissection in the groin during surgery for recurrent sapheno-femoral incompetence. DESIGN: Prospective, randomised study comparing three surgical techniques. METHODS: Thirty-six consecutive patients undergoing surgery for recurrent sapheno-femoral incompetence were randomised. Twelve patients underwent dissection with ultrasound, 12 with electrocoagulation and 12 controls had sharp dissection with ligation of scar and lymphatic tissue using absorbable suture material. RESULTS: The mean drain output per patient was 13.5 ml in the ultrasonic group, 15.4 ml in the electrocoagulation group and 8.3 ml in the suture ligation group. Six minor cases of lymphatic leakage occurred in the ultrasonic group. This resulted in no clinical problem. There were no other significant differences between the three groups. CONCLUSIONS: There is no detectable advantage for the use of ultrasound or electrocoagulation in recurrent saphenous high ligation compared to sharp dissection.     

Travel distance, age, and sex as factors in follow-up visit compliance in the post-gastric bypass population

BACKGROUND: There is no consensus regarding the optimal rate of follow-up in the post-bariatric surgery patient population. METHODS: The records of all patients who underwent laparoscopic Roux-en-Y gastric bypass from 2001 to 2003 were reviewed. Using patient zip codes, travel distances were calculated between the patients' places of residence and our clinic. Patients were then assigned to 1 of 3 cohorts according to the following distances: (1) < 50 miles, (2) 50 to 100 miles, and (3) > 100 miles. Patient compliance with follow-up appointments at 3 weeks, 3 months, 6 months, 9 months, and 12 months was analyzed. Linear trends were identified using the Mantel-Haenszel test. Age and sex were analyzed as possible predictors of compliance using the chi(2) test. P values < .05 were considered statistically significant. RESULTS: The study group comprised 150 patients (127 females and 23 males). The 3 cohorts contained 115, 21, and 14 patients, respectively. All patients in each cohort were compliant with the 3-week follow-up appointment. Although there were differences in compliance between cohorts at each of the remaining appointments, only the 9-month (70.3% vs 61.9% vs 35.7%) visit showed statistical significance (P = .035). The 6-month visit trended toward significance (85.2% vs 76.2% vs 64.3%; P = .088). Males were more likely to be compliant with the 12-month follow-up (P = .040). When controlling for sex, travel distance was also a predictor of compliance at this follow-up visit (P = .024). Age was not predictive of compliance (P = .827). CONCLUSION: Based on our findings, we conclude that travel distance from the clinic does not significantly affect compliance at the initial follow-up, 3-month, and 12-month appointments. However, distance does tend to affect compliance at the 6-month appointment and significantly affects compliance at the 9-month appointment. Males are more likely to be compliant at the 12 month follow-up visit. We must continue to strive for 100% follow-up in our post-bariatric surgery patients.     

P31 The relationship between the relative amount of Porphyromonas gingivalis in saliva and halitosis

Objectives  Porphyromonas gingivalis is one of the microorganisms that most actively produce CH₃SH and we have reported that subjects with P . gingivalis have higher CH₃SH levels than subjects without P .  gingivalis . However, little is known about the relationship between P . gingivalis levels in saliva and the condition of oral malodor. In this study, we evaluated the association between the relative amount of P . gingivalis in saliva and halitosis in mouth air.
Methods  All of the subjects were patients at the Preventive Dentistry and Breath Odor Clinic of Kyushu Dental College, where they received a periodontal examination. Volatile sulfur compounds (VSC: hydrogen sulfide and methyl mercaptan) were measured using gas chromatography. Saliva samples were collected in a sterile plastic tube over a period of 5 min while the subject chewed on paraffin wax, and were then immediately stored at –80°C until use. Template DNA was obtained from the stored saliva using an Easy-DNA Kit (Invitrogen, CA, USA) according to the manufacturer's instructions. Conventional PCR assays were used to confirm the presence of P . gingivalis . A 5' nuclease TaqMan PCR was used to quantify P . gingivalis in saliva. The relative numbers of bacteria were measured using the comparative threshold cycle method.
Results  We found a quantitative relationship between the P . gingivalis levels in saliva and the condition of halitosis in mouth air.
Conclusion  We analyzed the relationship between the relative amount of P . gingivalis in saliva and oral malodor.