The yield of single-strand breaks (ssb) and double-strand breaks (dsb) produced by alpha-particles at the end of their track in DNA-films was determined experimentally. Helium nuclei were accelerated to 600 keV in the 400 kV ion accelerator and scattered at a carbon target. The elastically scattered alpha-particles with energies of 344 keV and 485 keV were used to irradiate supercircular plasmid DNA in vacuo. For the dosimetry of the alpha-particles a surface barrier detector was used and the energy distribution of the alpha-particles determined. The energy loss of the particles in the DNA-layer was calculated. DNA samples were separated into the three conformational isomers using agarose gel electrophoresis. After fluorochromation the number of ssb and dsb per plasmid DNA molecule was established from the band intensities assuming the validity of Poisson statistics. Linear dose effect correlations were found for ssb and dsb per plasmid molecule. In the case of 344 keV-alpha-particles the yield of dsb was (8.6 +/- 0.9) x 10(-11) breaks/Gy x dalton. The ratio of ssb/dsb was 0.5 +/- 0.2. This is at least a factor of six larger than the ratio found in experiments with higher energy alpha-particles and from model calculations. Similar experiments with protons yielded a relative biological effectiveness (rbe) value of 2.8 for the induction of double-strand breaks by track end alpha-particles.

Alpha Particles↗

PubMedDate not supplied

Incidence and management of severe hypoglycemia in 434 adults with insulin-dependent diabetes mellitus.

The risk of severe hypoglycemia associated with the particular therapeutic approach of two University hospitals was assessed in 96% of all patients with insulin-dependent diabetes mellitus (IDDM) who had been admitted during a period of almost 3 yr to the diabetic wards of two hospitals and who participated in a structured teaching and treatment program. During a mean follow-up period of 18 mo, 10% of the conventionally treated patients (N = 384; age 30 +/- 13 yr; duration of diabetes 12 +/- 9 yr) and 9% of the CSII-treated patients (N = 50, age 28 +/- 7 yr, duration of diabetes 13 +/- 7 yr, total follow-up period 1093 patient-mo) experienced at least one severe hypoglycemic episode per year, and a total of 123 severe hypoglycemic episodes occurred. In a subgroup of 169 conventionally treated patients, mean glycosylated hemoglobin values decreased from 10.5 +/- 1.9% before participation in the program to 9.2 +/- 2.0% (P less than 0.001) 18 +/- 4 mo thereafter. For the CSII-treated patients, glycosylated hemoglobin values were 9.7 +/- 1.9% before initiation of pump therapy and remained at the upper normal range from 3 mo thereafter throughout the study. There was no relationship between glycosylated hemoglobin levels and the occurrence of severe hypoglycemic episodes. Fifty-three severe hypoglycemic episodes were treated with glucagon injections by the patients' relatives (all but one effectively), 30 were managed by assisting physicians, and 44 led to hospitalization. Thus, successful attempts to improve glycosylated hemoglobin values in an unselected group of patients with IDDM were not associated with an unduly high risk of severe hypoglycemia when compared with the scarce data from the literature.

Adolescent↗

PubMedDate not supplied

[The assessment of the nutritional status in patients with a resectable digestive tumor].

PROPOSAL: Tumoural disease leads to multifactorial cancerous cachexia. There are still few data available on the onset of this syndrome in operable patients, despite the repercussions on prognosis and the indication of nutritional support. GOAL: In this prospective study, we are considering the assessment of nutritional status in the light of the Chang protocol in with gastrointestinal tumours patients, as well as the possible differences depending on the location of the tumour, its progress, and the onset of septic complications. With this approach, we attempt to specify the indication of postoperative nutritional support. MATERIALS AND METHOD: The nutritional assessment protocol existing in the Department was reviewed as applied to 105 patients affected by oesophageal, gastric, pancreatic and colo-rectal cancer. This protocol included the ideal weight percentage (%IW), tricipital fold (TSF), arm muscle circumference (AMC), total albumin and lymphocytes (Chang protocol), as well as urea nitrogen. The database used was created in File Maker Pro running on a Macintosh computer and supported by the StatView programme for the statistical analysis of the results. RESULTS: There were 61 colo-rectal, 18 gastric, 17 oesophageal and 9 pancreatic carcinomas. There was some degree of malnutrition in 52.4% of patients but it was not severe in any case. An outstanding result is the percentage of ideal weight in excess of 100% on average in all of the groups, with little variation in the arm muscle circumference, as is the lower tricipital fold in the oesophageal and pancreatic cases. Albumin was significantly lower in gastric carcinoma cases and lymphocytes showed a correlation with the progress of the tumour and also with the onset of septic complications. The excretion of urea nitrogen did not reveal significant differences. In stages I and II, the patients were normally nourished or with marasmus, so that the only malnutrition found was of the kwashiorkor type and combined with stages III and IV. CONCLUSIONS: There is 52.4% of malnutrition in our surgically resectable digestive oncology patients using the Chang protocol, not susceptible of preoperative renourishment. This is found irregularly depending on the location and stage of the tumour. The total lymphocytes prior to surgery represented an independent variable which correlated with septic complications.

Anthropometry↗