Determination of 13C/12C-ratios in rumen produced methane and CO2 of cows, sheep and camels.

Naturally produced methane shows different delta 13C-values with respect to its origin, e.g., geological or biological. Methane-production of ruminants is considered to be the dominant source from the animal kingdom. Isotopic values of rumen methane--given in literature--range between -80/1000 and -50/1000 and are related to feed composition and also sampling techniques. Keeping cows, camels and sheep under identical feed conditions and sampling rumen gases via implanted fistuale we compared delta PDB 13C-values of methane and CO2 between the species. Referring to mean values obtained from 4 or 5 samples at different times of 11 animals (n = 47) we calculated delta PDB 13C-medians resulting in small but not significant differences within and significant differences between the species for CO2 and methane. The delta PDB 13C-differences between methane and CO2 were statistically equal within and also between the species. Therefore a linear regression of methane values on CO2 is appropriate and leads to: delta PDB 13C(methane)/1000 = 1.57 * delta PDB 13C(CO2)/1000 - 47/1000 with a correlation coefficient of r = 0.87.

Determination of (13)C/(12)C-Ratios in Rumen Produced Methane and CO(2) of Cows, Sheep and Camels.

Abstract Naturally produced methane shows different δ(13)C-values with respect to its origin, e.g., geological or biological. Methane-production of ruminants is considered to be the dominant source from the animal kingdom. Isotopic values of rumen methane-given in literature-range between -80‰ and -50‰ and are related to feed composition and also sampling techniques. Keeping cows, camels and sheep under identical feed conditions and sampling rumen gases via implanted fistulae we compared δ(PDB) (13)C-values of methane and CO(2) between the species. Referring to mean values obtained from 4 or 5 samples at different times of 11 animals (n = 47) we calculated δ(PDB) (13)C-medians resulting in small but not significant differences within and significant differences between the species for CO(2) and methane. The δ(PDB) (13)C-differences between methane and CO(2) were statistically equal within and also between the species. Therefore a linear regression of methane values on CO(2) is appropriate and leads to: δ(PDB) (13)C(methane)‰ = 1,57 * δ(PDB) (13)C(CO(2))‰-47‰ with a correlation coefficient of r = 0,87.

Influence on meat colour of spray-chilling the surface of pig carcasses.

The present study examines the influence of spray-chilling on the surface colour of the musculature, skin and spinal spongiosa of swine carcass halves. Thirty swine halves, of the commercial classification U, were divided into six experimental groups and chilled under varying conditions over a period of 20 h. Three of the experimental groups were sprayed periodically with 810 g drinking water within a 4-h chilling phase. The other three served as unsprayed control groups. Oxygenation of the myoglobin to oxymyoglobin was accelerated by spraying the surface of the musculature. Spray-chilling conditions had no influence on the formation of metmyoglobin. The colour of the sprayed ham musculature became lighter after 4 h of chilling. Red- and yellow-values decreased. There were no significant differences in the colour values after 20 h of chilling. The surface of the skin became lighter after spray-chilling. The spraying had no influence on the colour of the spinal spongiosa.

[Rapid temperature measurement by calculating the final temperature within the response time]. / Schnelle Temperaturmessung durch Berechnung der Endtemperatur vor der Einstellzeit.

For the early detection of an epidemic among animals in mass production, rapid information about the temperature of the animals is important. The response time of conventional thermometers is too long to permit rapid measurement. For adequate accuracy the measuring time required is about five times the response time. Using a microcomputer and regression computation, measurement of the final temperature can be effected within the period of a single response time. In addition, several thousand data can be stored for evaluation at a later date.

Somatic comparisons of urban and rural Russian boys, ages 6, 9, and 15 years, living in St. Petersburg and surrounding areas.

Somatic data were collected during September 1991 on 280 males, ages 6, 9, and 15 years, residing in urban St. Petersburg, Russia, and in rural regions surrounding the city. Comparisons are made between urban and rural groups for measures of body size and form, skinfold thicknesses, body mass index (BMI), and estimated arm muscle area (ARM). The data were analyzed in 2 (urban-rural) × 3 (age) analyses of variance, with an alpha level of P < 0.05. Age differences were evident for all measurements. A significant main effect for urban-rural was found for stature, lower limb height, and calf girth; differences approached significance (P < 0.07) for body weight and sitting height. Urban children were larger than rural children in stature, sitting height, lower limb height, calf girth, and body weight. The interaction was nonsignificant. Urban and rural boys did not differ on measures of body form. Similar means were obtained for the sum of skinfolds, the BMI, and ARM in urban and rural boys. Compared with data collected more than a century ago, present-day 15-year-olds are 22 cm taller. It has often been suggested that living in an urban environment provides greater access to the amenities of life than living in a rural area. Although these amenities are difficult to observe differences do exist and the secular trend continues. © 1994 Wiley-Liss, Inc.

Effect of energy metabolism on 13C/12C-ratios in milk fat and lactose of cows.

1. The ratios of stable carbon isotopes 13C/12C in milk constituents of Holstein dairy cattle were investigated by mass spectrometry. 2. Under physiological feeding conditions the natural abundance of 13C in lactose was greater than in milk fat. 3. Reduction of energy intake diminished the abundance of 13C in lactose resulting in values similar to those of fat. 4. It is suggested that by comparing the 13C/12C ratios in milk fat and lactose the metabolic energy state of cows may be rated.

Glucose entry rate in dairy cattle as determined by stable isotope 13C-labelled glucose at different stages of reproduction.

1. Uniformly labelled stable 13C-glucose was used to study glucose entry in high yielding Holstein cows (n = 8) under normal production conditions. 2. The single injection technique was repeated at three different reproductive phases. A two compartment model was applied to calculate mean entry rates of glucose resulting in: (1) Terminal phase of pregnancy (2 weeks a.p.): 0.41 g/hr/kg0.75; (2) Peak lactation (6 weeks p.p.): 0.97 g/hr/kg0.75; (3) End of lactation (37 weeks p.p.): 0.61 g/hr/kg0.75. 3. Data from studies using radioactively labelled tracers are in good agreement with our results obtained without any restrictions implied by the handling with radioactive substances.

Countermeasures for reducing the transfer of radiocesium to animal derived foods.

The nuclear reactor accident in Chernobyl stimulated new discussions and experiments on the question, how and to what extent the radiocesium-concentration in animal derived foods can be reduced. In a brief review this paper describes the use of two groups of feed additives as already applied in laboratory experiments during the period of atmospheric atomic weapons tests to prevent radiocesium absorption in the gastro-intestinal tract: 1) Iron (III) -Hexacyanoferrates and 2) Clay minerals. In the post-Chernobyl-period pilot studies were initiated to test similar feed additives under practical farming conditions with "naturally" radiocesium-labeled feedstuffs. Since then it is obvious that the colloidal Prussian blue analogue Ammonium-Ferric-Cyanoferrate (AFCF) can be considered as a leading antidote against radiocesium, while Bentonite or Bolus alba are 88-266 times less effective, when compared on a weight basis. Additionally clay materials cause losses of minerals and trace elements and pose logistic problems when feeding millions of large animals. Because of the small doses needed AFCF appears as a substance of choice to reduce radiocesium burdens in animal derived foods, which gained full recognition by health authorities in W-Germany and Austria supported by an official clearance for the use as feed additive.

Lack of a differential radiation response for proliferative and non-proliferative rat thyroid cells (FRTL-5) in vitro.

FRTL-5 rat thyroid epithelial cells maintain normal thyroid function and morphology in vitro, exhibit an absolute requirement for thyroid stimulating hormone (TSH) for proliferation and display radiation dose response characteristics indistinguishable from those of rat thyroid epithelial cells in vivo (Rad. Res. 105:138-146, 1986). In TSH-free medium cells remain in a non-proliferative, yet viable, state for prolonged periods of time and respond to TSH re-stimulation by a return to exponential growth. Flow cytometric analysis using two-step acridine orange (AO) staining revealed an accumulation of cells in the G1 phase of the cell cycle accompanied by a pronounced reduction in red fluorescence (indicative of RNA content) in FRTL-5 cells cultured in the absence of TSH. The response of proliferative and non-proliferative FRTL-5 cells to single dose, split dose and fractionated radiation was compared to determine whether proliferative status was an important response determinant. The response of FRTL-5 cells was not influenced by proliferative status at the time of irradiation. Additionally, dose response was not altered by variable (12 hr-8 days) non-proliferative intervals before or after irradiation. As revealed by split dose experiments, the rate and extent of sublethal damage repair was likewise similar for proliferative and non-proliferative cells. Multifraction experiments employing three fractions separated by 6 hr intervals indicate that non-proliferative FRTL-5 cells completely repair sublethal damage between fractions. These results indicate that the radiation response of FRTL-5 cells is not influenced by the proliferative status of the cells prior to or post-irradiation.

Metabolism of naturally occurring [13C]glucose given orally to horses.

In 5 horses, 13CO2/12CO2 ratios in expired air were determined using isotope mass spectroscopy to investigate metabolism of naturally occurring [13C]glucose. Oral glucose tolerance tests (OGTT) were performed using maize or beet glucose. Maize has a higher 13C concentration than that of most plants. The 13CO2/12CO2 ratios after OGTT was performed using maize glucose were compared with 13CO2/12CO2 ratios in expired air after OGTT was performed using beet glucose. The ratio also was determined during the period horses were not fed. Using OGTT, all horses were glucose tolerant. The OGTT performed using beet glucose led to minimal changes in 13CO2/12CO2 ratios. The 13CO2/12CO2 ratios decreased significantly (P less than 0.01) when horses were not fed. After oral dosing with maize glucose, 13CO2/12CO2 ratios reached maximal increases 5 hours after dosing and reached baseline values 15 hours after dosing.

A pilot study of whole body hyperthermia and local irradiation for advanced non-small cell lung cancer confined to the thorax.

Six patients with Stage III non-small cell lung cancer completed therapy which consisted of 4 whole body hyperthermia (WBH) treatments during the first 2 weeks of a 6 week course of radiotherapy (60 Gy). A radiant heat system was used to deliver the 41.8 degree C WBH. To reduce the danger of transverse myelitis, the spinal cord (and therefore part of the mediastinum and contralateral hilar region) was not irradiated during the first 2 weeks of radiotherapy and concurrent WBH. Subsequent treatments (weeks 3-6) included conventional irradiation to the primary tumor, mediastinal lymph nodes and spinal cord. Areas of gross disease responded to therapy in 5/6 patients. No radiation pneumonitis was observed. In 2/6 patients, relapse (after 10 months and 6 months, respectively) occurred with malignant pericardial effusions. The mediastinum in these patients was not an area of bulky disease involvement initially. To eliminate such WBH-radiation sanctuary zones, the protocol was modified to include greater combined WBH-radiation treatment. This is accomplished by having one WBH treatment "sandwiched" between 2 radiation fractions. The preclinical basis for the revised protocol is presented.

Synthesis, effectiveness and metabolic fate in cows of the caesium complexing compound ammonium ferric hexacyanoferrate labelled with 14C.

Adding ammonium ferric hexacyanoferrate (AFCF) to cows' fodder produced after the Chernobyl nuclear accident prevented milk contamination by increasing the faecal elimination of 137Cs. Synthesis of ammonium ferric hexa[14C]-cyanoferrate (AF14CF) and its purification were performed for the study of the metabolic fate of this complex, and the evaluation of the possible release of cyanide. The stability of this colloidal product, tested by anaerobic incubation in rumen juice in vitro, showed no release of free cyanide from AF14CF, but hexacyanoferrate was identified in the rumen juice and 0.13% of the added radioactivity was converted to labelled CO2. AF14CF administered per os to two cows showed a nearly quantitative excretion of radioactivity in faeces during the first 3 d (91-95%). A very low but significant level of radioactivity appeared in plasma, blood cells, expired CO2 and was detected in organs taken 9 d after administration. Total cumulative radioactivity in urine and milk amounted to 0.19-0.47% and 0.068-0.071% respectively for the two cows. Labelled hexacyanoferrate and thiocyanate were identified in the urine and also in faeces. In spite of this relative instability of AFCF in the rumen of cows, the poor absorption of AF14CF degradation products showed that AFCF constitutes an efficient and safe food additive to prevent the absorption of radioactive caesium from ruminant feed and its secretion in milk.

Progress in the management of childhood brain tumors.

The authors have attempted to summarize the contributions that have been made towards improvements in the management of children with brain tumors by the development of sophisticated imaging tools for diagnosis, by the development of more sophisticated and versatile neurosurgical tools, by refinements in radiation therapy delivery equipment and techniques, and by the introduction of chemotherapy into therapy regimens. Overall, the interaction of all of these modalities is stressed, culminating in a comprehensive multidisciplinary approach to the management of children with brain tumors.

Brain tumors in children. II. Advances in neurosurgery and radiation oncology.

In this article, the contributions of neurosurgery and radiation oncology to the management of childhood brain tumors are described. Progress in a particular discipline rarely occurs in an isolated fashion, and it is clear that neurosurgical advances owe much to similar advances in anesthesiology, neuroradiology, and intensive care management. These advances in various disciplines have all permitted bolder yet safer attempts at radical resection by the neurosurgeon. The goal of radical surgical resection is cure in the case of low-grade brain tumors. However, even in those situations where surgery alone cannot be curative, the reduction of tumor bulk facilitates the task of both radiation therapy and chemotherapy, with improvement in progression-free survival as well as overall survival. For those tumors that cannot be cured by surgical resection alone, the standard of therapy thereafter still remains irradiation of the residual tumor. It is clear that the single major advance in the treatment of childhood medulloblastoma has been Cushing's recognition of the value of craniospinal irradiation. Refinements in radiation machines and treatment planning have permitted more accurate delivery of radiation therapy with a slight reduction in toxicity. Newer approaches, such as hyperfractionated irradiation and interstitial irradiation, attempt to improve therapeutic efficacy while minimizing toxicity. Nevertheless, as more children are surviving their brain tumors following surgery and radiation therapy, the price of the successful therapy is being increasingly realized in terms of developmental deficits, particularly in the very young child. It is the desire of all those involved in the management of children with primary brain tumors to seek alternative approaches to wide-field irradiation of the brain in children with high-grade tumors.

Evaluation of the Xe-133 clearance method for indirect placental blood flow determination.

The Xe-133 clearance method, chosen by several groups for indirect placental blood flow (PBF) determination, is evaluated using a placenta-fetus compartment model first introduced by Moll (1973). The placenta is modelled as a strong concurrent, counter-current or cross-current exchange system. The fetal circulatory system is simplified by dividing it into two major branches: the umbilical circulation and the fetal tissue or systemic circulation. Following an arbitrary labelling of maternal arterial blood, Xe-133 concentrations in myometrium, placenta and fetus are derived from the model and are used to calculate placental clearance rates. The dependence of clearance rates on maternal and fetal PBF, on the distribution of fetal cardiac output, and on the effect of recirculation times, is considered in the three different arrangements of maternal and fetal placental vessels.

Somatic findings at age 9 years on three ethnic groups of Nigerian urban and rural boys.

Somatic data were collected in 1983 on 577 Nigerian boys age 9 years drawn from Ibo, Yoruba, and Hausa ethnic groups living in urban and rural locations. On each subgroup, measures of body size, body form, and body composition were analysed for central tendency and variability. From urban samples, means for standing height and body weight were highest on Ibo boys, intermediate on Yoruba boys, and lowest on Hausa boys. Ibo urban boys, on average, were larger than their rural peers by 5.9 cm in standing height, 3.3 kg in body weight, and near 1.5 cm in shoulder width, arm girth, and calf girth. From pooled urban and rural subgroups, calf girth relative to lower limb height was near 40% on Ibo boys, 39% on Yoruba boys, and 38% on Hausa boys. From the three ethnic groups combined, means for thickness of skin and subcutaneous tissue on the arm and abdomen were higher on urban than rural boys. Composite means for 494 Nigerian Ibo and Yoruba urban and rural boys were lower than means for 208 United States Black boys measured during 1974-1977 in Richland County, South Carolina, by 1.7 cm in standing height, 3.0 kg in body weight, and near 1.5 cm in arm girth and calf girth.