An elastically bent silicon crystal as a monochromator for thermal neutrons

Some experimental results are presented for an elastically bent perfect silicon crystal in a strongly asymmetric diffraction geometry as a neutron monochromator. The use of this unconventional geometry of the monochromator appears to be suitable for a wide (several centimetres) incident polychromatic beam, when, thanks to the spatial condensation of the diffracted neutrons (Fankuchen effect), a high monochromatic beam density may be obtained. Furthermore, when using focusing in real and in momentum space by adjusting an optimum bending radius, the intensity diffracted by a sample may be comparable even with the best mosaic monochromators such as highly oriented pyrolytic graphite (PG). A comparison is demonstrated on the rocking curves of a strongly mosaic Ni–Al(020) crystal obtained with the monochromatic beam from bent Si(111), Si(400) and from PG(002), Cu(220) mosaic monochromators.

Restriction site mapping of adenovirus types 9 and 15 and genome types of intermediate adenovirus 15/H9

Physical maps were established for seven genome types of the intermediate adenovirus (AV) 15/H9 and for the serologically related prototypes AV15 and 9 using the enzymes BamHI, BglII, and HindIII. The polarity of the fragment order was determined by hybridization with known AV2 fragments. AV15/H9 strains showed more restriction sites in common with AV9 than with AV15. The results are consistent with the hypothesis that intermediate AV15/H9 strains have emerged by recombination.

Half-strength TAC topical anesthetic. For selected dermal lacerations

A prospective evaluation of 75 consecutive children with lacerations of the face, lip, and scalp who received TAC (tetracaine, epinephrine [adrenalin], cocaine) topical anesthetic for the repair of their wound was performed. The TAC preparation contained one-half the conventional concentration of cocaine (5.9%) and tetracaine (0.25%) previously used in other studies that have evaluated its anesthetic efficacy. A maximal dosage of 3 ml of TAC (containing 175 mg cocaine and 7.5 mg tetracaine) was applied to each laceration. The diluted TAC preparation provided complete anesthesia for approximately 95% of the more than 400 sutures placed. No adverse reactions were noted in any patient who received TAC, and in no instance did a complication of wound healing occur. The original formulation of TAC was arbitrarily composed, and the maximum concentration per dosage of the potentially toxic component medications of TAC that can be "safely" applied to dermal lacerations in children remains to be defined. Utilization of this diluted preparation will diminish the risk of potential systemic toxicity from the absorbed component medications of TAC without compromising anesthetic efficacy.

The effect of feeding human milk and adapted milk formulae on serum lipid and lipoprotein levels in young infants

The effect of feeding with human milk and commercially available milk substitutes was studied in a group of 154 healthy infants during the first 3 months of life by assessment of body weight, body length, head circumference, skinfold thickness, serum lipid and lipoprotein concentrations. Human milk and the different milk formulae have the same energy content (kcal/100 ml) and total fat, total protein and total carbohydrate contents are comparable but they differ in respect of their fatty acid compositions. The various diets were chosen freely by the parents and the newborns were exclusively fed either human milk (n = 56), Multival 1 (n = 31), Humana 1 (n = 33), or Pre Aptamil (n = 34). No significant differences in body weight, body length or head circumference were observed between any of the different dietary groups. Fat storage, as assessed by measurements of skinfold thickness, was significantly less in breast-fed children compared to those on the formula diets. Breast-fed and Pre Aptamil-fed infants had the highest levels of total serum cholesterol, low density lipoprotein (LDL)-cholesterol and LDL. No differences were observed in the levels of total serum triglycerides, very low density lipoprotein (VLDL)- and high density lipoproteins (HDL)-cholesterol, VLDL and HDL. There were no strong correlations between the physical and the biochemical parameters. No indication of an increased risk of developing atherosclerosis was associated with any of the dietary treatments for the duration of this study. However, these investigations support the hypothesis that subtle early nutritional variation can influence mechanisms that regulate lipoprotein and cholesterol levels in later life.

Efficacy of TAC topical anesthetic for repair of pediatric lacerations

A prospective evaluation of 103 consecutive children who received TAC (tetracaine, epinephrine [adrenaline], cocaine) liquid topical anesthetic for the repair of their minor dermal lacerations was performed. A unique method of TAC application was used that consisted of applying the medication to the inner margins of the wound cavity and allowing it to stand for several minutes prior to the application of a TAC-saturated gauze pad to the wound surface. Of 670 sutures placed, 637 (95%) were done without eliciting pain. The TAC topical anesthetic was more than 95% effective in providing complete anesthesia for wounds located on the face and lip; it was equally efficacious in anesthetizing larger wounds (greater than or equal to 5 cm in length and/or greater than or equal to 5 mm in depth). No adverse reactions resulted from the application of TAC. A single wound healing complication occurred in 103 patients. TAC is a safe, effective method for anesthetizing minor lacerations of the skin in children. Its painless method of application relieves patient discomfort and maximizes patient compliance during the repair procedure, both of which enhance the accurate approximation of lacerated tissue.

Prostaglandin E1 (PGE1) gastric tissue levels in the rat after truncal vagotomy and/or pre-hepatic portal hypertension

Three groups of female Wistar rats were considered to study the pathophysiologic changes induced by truncal vagotomy and/or prehepatic portal hypertension. The first group was subjected to transabdominal bilateral truncal vagotomy (T.V.) and Heinecke-Mikulicz pyloroplasty, the second group to main portal vein partial stenosis (P.P.S.), and the third one simultaneously to T.V. plus P.P.S. The rats were sacrificed and the stomach homogenized. The separation and simultaneous measurement of gastric prostaglandin E1 (PGE1) resulted from high performance liquid chromatography (H.P.L.C.). Mass spectrometry (M.S.) was used for identification of several gastric PGE1 samples in purified extracts. Control rats were also sacrificed and examined. With regard to PGE1 gastric contents, the following results are reported: 1.2405 +/- 0.1356 micrograms/g (control rats), 0.786 +/- 0.1296 micrograms/g (T.V. rats), 1.8495 +/- 0.3433 micrograms/g (P.P.S. rats), and 1.2754 +/- 0.1154 micrograms/g (T.V. + P.P.S. rats). The interpretation of results is made at the moment on a hypothetical basis.

The levels of immunoglobulins (IgG. IgA. IgM) under the effect of age and exposure to the mining environment in uranium industry

IgG, IgA, and IgM levels were measured in 347 miners working in the underground of uranium mines; in 156 men entering into the work in mines, and in 101 men working in food industry and food distribution, all in the region of Central Bohemia. Significantly elevated IgG and IgM levels were found in the subgroup of miners exposed a short time (less than five years) to the mining environment, whereas elevated IgA levels were found in the subgroup exposed more than 15 years. The comparison of differences with age-matched controls has shown that the levels of IgM are significantly increased in the miners subgroup exposed to the mining environment no more than five years. In miners subgroups above 31 years a significant decline of IgG levels occurs. The expression of Ig levels' changes is not uniform in all exposed persons; an apparent heterogeneity occurs in miners population. Some differences in IgG and IgM levels were found between the two 31- to 40-year-old control subgroups. The possible conditions for differences found are discussed from the point of view of the effect of ionizing radiation and from the point of view of the stressing influence of environment and employment.

Levels of alpha1-antitrypsin in the spring and autumn seasons

In a group of 84 pairs of 11-year-old children of both sexes, the level of the alpha1-antitrypsin (alpha1-AT) were ascertained in the autumn and spring. Although the mean levels of alpha1-AT in the two seasons hardly differed, the highly significant seasonal changes in the distribution curves of alpha1-AT values were noted in boys, whereas the levels showed higher stability in girls.

[New methods in vascular surgery. Intraoperative transluminal catheter-recanalization using Dotter's technic]

The combination of vascular operative procedures and transluminal recanalization with a Dotter-catheter is recommended. According to own results this has been proven to be very successful, especially in old patients or in patients in a reduced physical state. The main advantage is a shorter duration of the surgical procedures and a reduction of the operative stress situation compared to other surgical methods. For the application of the Dotter-technique, however, it is necessary to observe the indications carefully.

Immunoglobulins under the influence of nonspecific factors. III. Immunoglobulins, pertussis antibodies and lysozyme in three child populations exposed to different air pollution

The levels of IgG, IgA, IgM, lysozyme, agglutinins against B. pertussis and B. parapertussis were followed in the blood serum of 306 children 9--10 years old in 3 areas of Central Bohemian region. In children dwelling in areas with more polluted air significantly higher levels of serum lysozyme and of parapertussis antibodies were found by the t-test. The distribution of these values shows significant differences between more polluted areas in comparison with lower-pollution area also in Kolmogorov-Smirnov test. The average levels of Ig approached statistically critical values but did not reach them, but significant differences in the distribution of values of IgG and IgA were shown by the F-test and chi2-test between lightly and heavily polluted areas. The values of immunological reactions in polluted areas were always higher than in the non-polluted group. This provides evidence for a hypothesis about a stimulatory effect of polluted air on immunological mechanisms in child population. The higher values of IgM observed recently by other authors in women were shown in girls of 9--10 years.

Transformation of lymphocytes in patients with certain bacterial infections

The state of cell-mediated immunity was measured by the morphological method of lymphocyte transformation with and without PHA, in a group of 56 patients with bacterial infections and in a group of healthy controls. The patients were divided into three subgroups according to the aetiology: 1. Patients with Gram-positive infections, 2. Patients with Gram-negative infections, and 3. mixed infections. The transformation values with PHA were significantly (t-test) higher in the Gram-positive subgroups than in the control group. Transformation in cultures stimulated by PHA was much higher in the subgroup of patients with Gram-positive aetiology; the difference between the values in the Gram-negative and in the Gram-positive subgroups was also significant. A decrease of transformation value below 50% was observed in 6 out of 18 patients with Gram-negative aetiology, whereas in the Gram-positive group it was noted in only 2 out of 21 patients.

Dispersed rat parotid acinar cells. II. Characterization of adrenergic receptors

The in vitro characterization of adrenergic receptors in isolated rat parotid acinar cells was accomplished through investigations of the transmembrane influxes of K and of the secretion of amylase in response to interactions of the cells with selected agonists and antagonists. Interaction of epinephrine (EPI) at concentrations of 10(-3)-10(-9) M with the alpha-adrenergic receptors resulted in rapid efflux of K from the cells. This effect was inhibited by phentolamine but not by propranolol or atropine. The process of secretion of amylase by these cells involved the activation of the beta-adrenergic receptors by the adrenergic agonists DL-isoproterenol (IPR) and EPI at similar to above concentrations. The interaction of these agonists with the beta receptors was inhibited by propranolol but not by phentolamine or atropine. Dibutyryl clclic AMP stimulated secretion of amylase at concentrations of 10(-8) M. A progressive increase in the secretory response of the cells was observed with increases in the dibutyryl cyclic AMP concentrations up to 10(-5) M. This effect was not inhibited by propranolol. This study demonstrates that dispersed rat parotid acinar cells have functionally intact adrenergic receptors and could be used as experimental tools for the studies of receptor physiology and pharmacology as well as other aspects of secretion at the cellular level.

Immunoglobulins under the influence of nonspecific factors II. The influence of work-stress on levels of immunoglobulins (IgG, IgA, IgM) of miners in uranium mines

In 2 groups of 22 miners each, exposed 5.4 and 10.8 years respectively to the environment of uranium mines, the serum levels of IgG, IgA, and IgM were measured before and after one workshift. In the group longer exposed the work-stress resulted in a significant decrease of all 3 classes of Ig. In the group exposed for a shorter time only the IgG decreased significantly. In the group longer exposed the initial levels of IgG were considerably lower in comparison with the group exposed for a shorter time.

Investigation of immunoglobulin (IgG, IgA, IgM) levels in the blood serum of uranium miners after higher and lower exposure to ionizing radiation

The levels of IgG, IgA and IgM were measured in the blood serum of uranium miners in a minin-district, where after a geological disturbance exposure to a high level of ionizing radiation took place. The mean exposure to 222-Rn daughters after first year was 7.35 WLM, after the second year 0.13 WLM only. Serum was sampled before miners started their occupation, for the second time after the first year and for the third time after the second year. The levels of IgG and IgM significantly decreased after one year of exposure, while the IgA changed only slightly. After the second year the levels of IgG and IgM significantly rose. IgG exceeded the initial levels: a regenerative hypercompensation took place. On the other hand IgA at the same time decreased. The IgG levels are only slightly correlated with radiation dose rate; for IgA and IgM the correlation is lacking. Individual Ig levels appear to be very variable. The reduction of IgG reached hypogammaglobulinemic levels in some miners after the first year and was followed by a propensity to infections of the respiratory tract. The significance of these observations is discussed from the immunological, radiological and radiohygienical point of view.