Optimizing the Analytical Performance of Substrate-Integrated Hollow Waveguides: Experiment and Simulation.

The goal of this technical note was to compare experimentally and via simulation of eight substrate-integrated hollow waveguide (iHWG) designs, and to predict promising future iHWG structures in lieu of experiments. The iHWGs differed in their geometry (i.e., inlet funnel cross-section and inner channel cross-section), as well as in their material properties (i.e., type of metal, polish of inner channel). Experimentally, calibration functions of isobutane as a model analyte were determined, and the analytical figures of merit, i.e., signal-to-noise ratio, limit of detection, were evaluated for each iHWG. Evaluation of the amount of radiation incident at the real-world and simulated detector revealed that experiment and simulation were in excellent agreement. While material and quality of the inner channel wall did not have a significant influence on the performance, the iHWG geometry profoundly affected the performance in terms of light throughput: Increasing the inlet funnel dimensions and the inner channel cross-section benefits light throughout, and thus, the analytical signal. Based on these results, simulations of not yet fabricated iHWGs were performed and promising new iHWG structures were suggested.

Hybrid Analytical Platform Based on Field-Asymmetric Ion Mobility Spectrometry, Infrared Sensing, and Luminescence-Based Oxygen Sensing for Exhaled Breath Analysis.

The reliable online analysis of volatile compounds in exhaled breath remains a challenge, as a plethora of molecules occur in different concentration ranges (i.e., ppt to %) and need to be detected against an extremely complex background matrix. Although this complexity is commonly addressed by hyphenating a specific analytical technique with appropriate preconcentration and/or preseparation strategies prior to detection, we herein propose the combination of three different detector types based on truly orthogonal measurement principles as an alternative solution: Field-asymmetric ion mobility spectrometry (FAIMS), Fourier-transform infrared (FTIR) spectroscopy-based sensors utilizing substrate-integrated hollow waveguides (iHWG), and luminescence sensing (LS). By carefully aligning the experimental needs and measurement protocols of all three methods, they were successfully integrated into a single compact analytical platform suitable for online measurements. The analytical performance of this prototype system was tested via artificial breath samples containing nitrogen (N2), oxygen (O2), carbon dioxide (CO2), and acetone as a model volatile organic compound (VOC) commonly present in breath. All three target analytes could be detected within their respectively breath-relevant concentration range, i.e., CO2 and O2 at 3-5 % and at ~19.6 %, respectively, while acetone could be detected with LOQs as low as 165-405 ppt. Orthogonality of the three methods operating in concert was clearly proven, which is essential to cover a possibly wide range of detectable analytes. Finally, the remaining challenges toward the implementation of the developed hybrid FAIMS-FTIR-LS system for exhaled breath analysis for metabolic studies in small animal intensive care units are discussed.

Portable combination of Fourier transform infrared spectroscopy and differential mobility spectrometry for advanced vapor phase analysis.

Designing mobile devices for the analysis of complex sample mixtures containing a variety of analytes at different concentrations across a large dynamic range remains a challenging task in many analytical scenarios. To meet this challenge, a compact hybrid analytical platform has been developed combining Fourier transform infrared spectroscopy based on substrate-integrated hollow waveguides (iHWG-FTIR) with gas chromatography coupled differential mobility spectrometry (GC-DMS). Due to the complementarity of these techniques regarding analyte type and concentration, their combination provides a promising tool for the detection of complex samples containing a broad range of molecules at different concentrations. To date, the combination of infrared spectroscopy and ion mobility techniques remains expensive and bound to a laboratory utilizing e.g. IMS as prefilter or IR as ionization source. In the present study, a cost-efficient and portable solution has been developed and characterized representing the first truly hyphenated IR-DMS system. As a model analyte mixture, 5 ppm isopropylmercaptan (IPM) in methane (CH4) were diluted, and the concentration-dependent DMS signal of IPM along with the concentration-dependent IR signal of CH4 were recorded for all three hybrid IR-DMS systems. While guiding the sample through the iHWG-FTIR or the GC-DMS first did not affect the obtained signals, optimizing the IR data acquisition parameters did benefit the analytical results.

Risk factors for inadequate emergence after anesthesia: emergence delirium and hypoactive emergence.

AIM: Inadequate emergence after anesthesia in the adult patient may be distinguished by the patients' activity level into two subtypes: emergence delirium and hypoactive emergence. The aim of this study was to determine the incidence of inadequate emergence in its different forms, to identify causative factors and to examine the possible influence on postoperative length of stay in the recovery room and in the hospital. METHODS: In this prospective observational study, 1868 non-intubated adult patients who had been admitted to the recovery room were analyzed. Inadequate emergence was classified in its different forms according to the Richmond agitation and sedation scale (RASS) 10 minutes after admission to the recovery room. Emergence delirium was defined as a RASS score >or=+1, and hypoactive emergence was defined as a RASS score

Left atrial shortening fraction in fetuses with and without myocardial hypertrophy in diabetic pregnancies.

OBJECTIVE: To test the hypothesis that, in diabetic pregnancies, left atrial shortening fraction (LASF) is decreased in fetuses with myocardial hypertrophy, compared to those without hypertrophy and to fetuses of non-diabetic mothers. METHODS: Fetal echocardiography was performed in women with pre-existing or gestational diabetes and in non-diabetic controls between 25 weeks' gestation and term. LASF was calculated using the formula: (end-systolic diameter-end-diastolic diameter)/end-systolic diameter, and data were compared between diabetic women with and without fetal myocardial hypertrophy and controls. RESULTS: The study population comprised 53 diabetic women and 45 controls. Out of the 53 fetuses of diabetic women, 14 had myocardial hypertrophy and 39 had normal septal thickness. Gestational age at the time of examination did not differ significantly between the control group and the two diabetic subgroups (P = 0.57). Fetuses with myocardial hypertrophy presented a mean ( +/- SD) LASF of 0.32 +/- 0.11, those without myocardial hypertrophy 0.46 +/- 0.12, and those of normal mothers 0.53 +/- 0.09 (P < 0.001). A significant inverse linear correlation was observed between LASF and septal thickness (r = - 0.51, P < 0.001). CONCLUSIONS: In diabetic pregnancies, LASF is lower in fetuses with myocardial hypertrophy than it is in those without hypertrophy and in fetuses of non-diabetic women, suggesting that LASF could be a useful alternative parameter in the assessment of fetal diastolic function.

[Osteochondrosis dissecans of the hip in adults--differential diagnosis of free joint bodies--case report]. / Osteochondrosis dissecans der Hüfte beim Erwachsenen -- Differenzialdiagnostik freier Gelenkkörper -- Fallbeschreibung.

The causes of hip pain in adults can vary greatly. We present the case of a 44-year-old woman with recurrent hip pain over a period of years. Medical history and clinical examination did not provide any decisive information. The X-rays revealed a loose body in the cavity of the hip joint. The MRI scan made the following differential diagnosis plausible: osteochondrosis dissecans coxae, osteochondroma and chondromatosis. The final diagnosis of osteochondrosis dissecans coxae was confirmed by surgical dislocation of the hip as modified by Ganz and histological examination of the loose body. This case supports the importance of including rare lesions in the differential diagnostic work-up of joint pain. The advantages of the offset operation as modified by Ganz versus arthroscopy of the hip are outlined.

Effects of lactulose on the intestinal microflora of periparturient sows and their piglets.

The periparturient period of animals (and humans) is very stressful and influenced by the microecosystem of the gastrointestinal tract (GIT). Performance and productivity of animal husbandry depend on the health of animal mothers and their offspring. We investigated the influence of prebiotic amounts of lactulose in sows and their piglets. Two experimental trial sows received daily 30 ml lactulose, 71 field trial sows received daily 45 ml lactulose during their periparturient period (10 days before until 10 days after parturison). The weaners of trial sows received 15 ml lactulose per 1 kg baby food 10 days before and 10 days after weaning.The effect of lactulose was recorded by performance parameters like number of piglet born alive, losses until weaning, body mass of piglets, daily weight gain of weaners until 35 days after weaning. The effect of lactulose on GIT microflora was estimated by bacterial counts of faeces of sows (total aerobic bacteria, Gram-negative bacteria, Clostridium (C.) perfringens). In order to show a previously unknown effect of lactulose we investigated the levels of antibodies to phospholipase C (PLC) of C. perfringens in plasma of experimental sows and in colostral and ripe milk of field sows. Lactulose influenced the performance parameters of sows in a non-significant way. In case of weaners we recorded significant daily weight gains. Lactulose significantly influenced total aerobic bacterial counts, C. perfringens counts in faeces of sows 20 days after parturison. Under experimental conditions it was shown that trial sows and their piglets had higher IgG-antibody levels to C. perfringens PLCs than the control animals. Similar results were found under field conditions. Trial sows had significant higher IgG-anti LPS (J5) antibodies in milk 10 days after birth.

Cholecystokinin-B/gastrin receptor binding peptides: preclinical development and evaluation of their diagnostic and therapeutic potential.

The high sensitivity of pentagastrin stimulation in detecting primary or metastatic medullary thyroid cancer (MTC) suggests widespread expression of the corresponding receptor type on human MTC. Indeed, autoradiographic studies demonstrated cholecystokinin (CCK)-B/gastrin receptors not only in >90% of MTCs but in a high percentage of small cell lung cancers and potentially a variety of gastrointestinal adenocarcinomas. In a pilot study, we have demonstrated the feasibility of radiolabeled gastrin-I to target CCK-B receptor-expressing tissues in vivo in animals and patients (T. M. Behr et al., Eur. J. Nucl. Med., 25: 424-430, 1998). The aim of the present study was to systematically optimize, in a preclinical model, suitable radioligands for targeting CCK-B receptors in vivo. For this purpose, a variety of CCK/gastrin-related peptides, all having in common the COOH-terminal CCK-receptor binding tetrapeptide sequence Trp-Met-Asp-PheNH2 or derivatives thereof, were studied. They were radioiodinated by the Iodogen or Bolton-Hunter procedures. The peptides tested were members of the gastrin- or cholecystokinin families or possessed characteristics of both, which differ by the intramolecular position of a tyrosyl moiety (occurring in native or sulfated form). Their stability and affinity were studied in vitro and in vivo; their biodistribution and therapeutic efficacy were tested in nude mice bearing s.c. human MTC xenografts. Diethylene-triamine-pentaacetate derivatives of suitable peptides were synthesized, evaluated, and labeled with (111)In. All members of the CCK or gastrin family were stable in serum (with t(1/2)s of several hours at 37 degrees C); nevertheless, the stability of those peptides was highest that bore the NH2-terminal pGlu residues (e.g., big gastrin, gastrin-I, caerulein, and others) or D-amino acids. In accordance to their comparably low affinity, nonsulfated members of the CCK family showed fairly low uptake in the tumor and other CCK-B receptor-expressing tissues (e.g., the stomach). Sulfated CCK derivatives performed significantly better but additionally displayed a high uptake in normal, CCK-A receptor-expressing tissues (such as the liver/gallbladder, pancreas, and bowel). Best tumor uptake and tumor:nontumor ratios were obtained with members of the gastrin family, probably because of their selectivity and affinity for the CCK-B receptor subtype. Pilot therapy experiments in MTC bearing animals showed significant antitumor efficacy as compared with untreated controls. (111)In-Labeled diethylene-triamine-pentaacetate derivatives of minigastrin showed excellent targeting of CCK-B receptor-expressing tissues in animals and a normal human volunteer. These data suggest that CCK/gastrin analogues may be a useful new class of receptor binding peptides for diagnosis and therapy of CCK-B receptor-expressing tumors, such as MTC or small cell lung cancer. Nonsulfated gastrin derivatives may be preferable because of their CCK-B receptor selectivity, and hence, lower accretion in normal CCK-A receptor-expressing organs. Further preclinical as well as clinical studies are ongoing.

Development during single IVP of bovine oocytes from dissected follicles: interactive effects of estrous cycle stage, follicle size and atresia.

Previous work suggests that a number of factors such as follicle size, day of estrous cycle, and level of atresia influence the developmental potential of bovine oocytes in vitro. To understand better the interactions of these factors, 1299 follicles > or =3 mm in diameter were dissected from ovaries of synchronized dairy cows on four days (d2, d7, d10, or d15) during the estrous cycle. The oocyte from each follicle was collected and matured, fertilized, and cultured singly to d8 (d0 of culture = IVF). Control follicles (302) were similarly dissected and processed from an ovary pair randomly collected from the abattoir on each slaughter day. Results showed that development to blastocyst was greater in oocytes collected during phases of follicular growth (d2 and d10) than those collected during phases of follicular dominance (d7 and d15; 44.8% vs. 36.0%, respectively: P < 0.001) over all follicle size categories (3-5 mm, 6-8 mm, 9-12 mm and > or =13 mm). Oocyte competence tended to increase with increasing follicle size (P < 0.1). Follicular cells from follicles containing an oocyte that developed to morula or greater by d8 (484 samples) were analyzed by flow cytometry to measure the level of apoptosis. Results showed an increase in mean percent apoptotic cells in subordinate follicles (18.65 +/- 0.86 over all size categories), particularly those of medium size (25.55 +/- 2.2 for 6-8 mm size follicles; P < 0.001), during the dominance phase compared to growth phase (9.25 +/- 0.95 over all sizes; P < 0.05). These results show a significant affect of the stage of estrous cycle on both oocyte competence and levels of follicular atresia.

Visicorrafia extramucosa con sutura absorbible sintética monofilamento en ratas Wistar / Extramucosal suture of the bladder using absorbable suture material: experimental study

El objetivo del trabajo es comparar los resultados con dos tipos de suturas en vesicorrafias realizadas en un plano.Se efectuó una vesicorrafia extramucosa en 48 ratas Wistar separadas en 2 grupos(n=24):en el primero con catgut 6-0 y en el segundo con polidioxanona(PDS)6-0.Cada grupo fue divido en 3 subgrupos según en momento del sacrificio:7,14 o 28 días luego de la cirugía.Se estudió la presencia de litiasis,alteraciones en los puntos de las suturas y la actividad inflamatoria,aguda y crónica.La litiasis ocurrió en los subgrupos a los 7 días(1),14 días(1),28 días(1)en el grupo catgut a los 14 días(3)y 28 días(1)La granulación,el edema y la presencia de células gigantes fue significativamente mayor en los subgrupos tratados con catgut.El número de macrógrafos y de polimorfonucleares fue mayor en el grupo suturado con catgut a los 7 y 14 días,como también el número de linfocitos a los 28 días.La polidioxanona produjo menor reacción inflamatoria aguda y crónica que el catgut

Visicorrafia extramucosa con sutura absorbible sintética monofilamento en ratas Wistar / Extramucosal suture of the bladder using absorbable suture material: experimental study

El objetivo del trabajo es comparar los resultados con dos tipos de suturas en vesicorrafias realizadas en un plano.Se efectuó una vesicorrafia extramucosa en 48 ratas Wistar separadas en 2 grupos(n=24):en el primero con catgut 6-0 y en el segundo con polidioxanona(PDS)6-0.Cada grupo fue divido en 3 subgrupos según en momento del sacrificio:7,14 o 28 días luego de la cirugía.Se estudió la presencia de litiasis,alteraciones en los puntos de las suturas y la actividad inflamatoria,aguda y crónica.La litiasis ocurrió en los subgrupos a los 7 días(1),14 días(1),28 días(1)en el grupo catgut a los 14 días(3)y 28 días(1)La granulación,el edema y la presencia de células gigantes fue significativamente mayor en los subgrupos tratados con catgut.El número de macrógrafos y de polimorfonucleares fue mayor en el grupo suturado con catgut a los 7 y 14 días,como también el número de linfocitos a los 28 días.La polidioxanona produjo menor reacción inflamatoria aguda y crónica que el catgut

Influence of the dominant follicle on oocytes from subordinate follicles.

As the oocyte grows within the follicle, a number of factors influence its health and developmental competence. These factors include follicle size, day of estrous cycle, level of atresia and influence of other follicles such as the dominant follicle. Follicles were dissected from ovaries of synchronized dairy cows on four days during the estrous cycle, and the oocyte from each follicle collected, matured, fertilized and cultured singly until Day 8. Development to blastocyst was greater in oocytes collected during phases of follicular growth than those collected during phases of follicular dominance (P<0.001) over all follicle size categories. Oocyte competence tended to increase with increasing follicle size (P<0.1). Follicular cells analyzed by flow cytometry showed an increase in proportion of apoptotic cells in subordinate follicles during the dominant phase compared to growth phase (P<0.05). Thus, the dominant follicle on both oocyte competence and levels of atresia. Further studies on the effect of dominance has shown that lactate production in cumulus-oocyte-complexes (COCs) from medium-sized follicles collected during a dominance phase and small follicles collected during a growth phase are no different from other follicles, despite having significantly lower uptake of glucose (P<0.1). Thus, COCs from different follicle subclasses differ in their nutrient requirements, and current IVM technology needs further improvement to better assist those oocytes that are developmentally challenged.

Food intake after adrenaline and noradrenaline injections into the hypothalamic paraventricular nucleus in pigeons.

The effects of local injections of adrenaline (Adr, 6 nmol) or noradrenaline (Nor, 16 nmol) into the paraventricular nucleus (PVN) and into other anterior hypothalamic districts on feeding behavior were examined in satiated pigeons bearing a chronically implanted cannula. When infused into the PVN, both Adr and Nor reliably elicited feeding responses during the first hour after the injection. Feeding responses to Adr injections were significantly higher than those evoked by Nor. Other behavioral measurements (sleep, exploratory, and preening) were not affected by these treatments. Local pretreatment with phentolamine (20 nmol) but not with propranolol (20 nmol) abolished the feeding response induced by both Adr and Nor into the PVN. Lateral hypothalamic sites were also shown to respond to catecholamine injections with an increase in feeding, followed also by an increased sleep-like behavior duration. Together with other evidence, the present results indicate that adrenergically mediated circuits into the avian PVN play an important role in the mechanisms of food intake control, equivalent to that observed in mammalian species.

Development of bovine embryos in single in vitro production (sIVP) systems.

Single in vitro production (sIVP) of embryos enables the study of developmental parameters of individual oocytes or embryos. Because several previously published sIVP systems showed varying levels of success, we attempted to design a simple, semidefined sIVP system that resulted in developmental rates similar to those obtained through group production (gIVP). In a 5 x 3 x 4 factorial experiment, 4200 oocytes were randomly assigned to combinations of various maturation (sIVM), fertilization (sIVF), and culture (sIVC) treatments based on media TCM199 (5 treatments), TALP (3 treatments), and SOF/aa/BSA (4 treatments), respectively. All sIVP steps were carried out in 10-12 microl drops under oil. Embryo development to blastocyst on days 7 and 8 of culture was determined and blastocyst cell numbers measured as an indicator of embryo quality. No interaction was found within any combination of sIVM, sIVF and sIVC treatments. Also, there was no difference in percentage of development to various stages for embryos in any of the sIVM or sIVF treatments (over all treatment combinations). However, when treatment combinations included charcoal-treated serum addition on day 5 of culture, a significant increase in development (39.0% total blastocysts/total oocytes vs. 22.7, 23.8 and 23.5% for the other 3 sIVC treatments, respectively; P < 0.001) and decrease in mean cell number (114.2 vs. 149.1, 150.5 and 143.7 cells, respectively; P < 0.001) was observed. These results are comparable to those routinely obtained in this laboratory with gIVP and establish standard conditions for individual embryo production.

In vitro and early in vivo development of sheep gynogenones and putative androgenones.

Genomic imprinting, where only one of the two parental genes is expressed, occurs in many phyla. In mammals, however, this phenomenon has been primarily studied in mice, and to a lesser extent, in humans. To understand how genomic imprinting may affect development in other species, particularly those with a different mode of placental development from mice and humans, 339 sheep zygotes were micromanipulated to contain either 2 large (presumptive male) or 2 small (presumptive female) pronuclei. One hundred and twenty-seven of these embryos and 86 manipulated and nonmanipulated control embryos were transferred to recipient ewes over 3 breeding seasons. Twenty-one control and 7 experimental conceptuses were recovered on day 21. Four of these conceptuses derived from zygotes with 2 small pronuclei were identified by karyotyping to be gynogenones (maternal-derived genome). While the gross morphology of the embryos appeared no different to those of normal controls, the extra-embryonic tissue from the conceptuses showed some hypertrophy and hypervascularization. Preliminary Northern blots of mRNA from allantoic and trophoblast tissue showed an overexpression of H19 and an underexpression of IGF2. Although the sheep gynogenetic phenotype contrasts with that seen in mice, these two genes appear to be similarly differentially expressed.

Estudo da história natural da hipertrofia miocárdica e sua associação com hiperinsulinismo em filhos de mães diabéticas / Study of the natural history of myocardial hypertrophy and its association with hyperinsulinism in infants of diabetic mothers

OBJETIVO - Testar a hipótese de associação entre hipertrofia miocárdica e níveis aumentados de insulina no soro de filhos de mães diabéticas, além de determinar a freqüência de regressão espontânea e o momento de sua ocorrência. MÉTODOS - Foram estudados 72 pacientes (54 filhos de mães diabéticas e 18 controles). O diagnóstico de hipertrofia miocárdica foi realizado por ecocardigrafia pré-natal, uni e bidimensional. Os registros da insulina amniótica foram obtidos de um estudo pré-natal prévio sobre hipertrofia miocárdica, pois a participação das gestantes era comum aos dois projetos. RESULTADOS - Houve 10 (18,52 'por cento') casos de hipertrofia miocárdica entre os filhos de mães diabéticas. As medidas do septo foram significamente diferentes entre os grupos (filhos de mães diabéticas e controles) na avaliação com 1 mês (p=0,04). A insulina manteve-se elevada nos filhos de diabéticas até 3 meses de idade, período em que era significantemente diferente em relação aos controles (p=0,003 e p =0,001, com 1 mês e 3 meses, respectivamente). A associação entre a regressão do septo interventricular e a regressão dos níveis de insulina ocorreu até 1 mês de idade. CONCLUSÄO - Houve regressão espontânea das medidas do septo interventricular até 6 meses de idade e a associação entre hiperinsulinismo e hipertrofia miocárdica esteve presente até 1 mês de idade.

[Natural history of myocardial hypertrophy and its association with hyperinsulinism in infants of diabetic mothers]. / Estudo da história natural da hipertrofia miocárdica e sua associação com hiperinsulinismo em filhos de mães diabéticas.

PURPOSE: To test the hypothesis that myocardial hypertrophy is associated with increased serum insulin levels in children of diabetic mothers and to determine the frequency and timing of this spontaneous regression. METHODS: Seventy-two patients were studied (54 children of diabetic mothers and 18 controls). Diagnosis of myocardial hypertrophy was made by fetal echocardiography. Amniotic fluid insulin levels were obtained from a previous prenatal study on hypertrophic cardiomyopathy, since the participation of the mothers was common to both projects. RESULTS: There were 10 cases of myocardial hypertrophy among children of diabetic mothers (18.52%). Septal thickness was significantly different between the 2 groups (children of diabetic mothers and controls) in the evaluation performed at the age of 1 month (p = 0.04). Insulin levels were still increased in children of diabetic mothers until the age of 3 months. During this period insulin levels were significantly higher than those of controls (p = 0.003 and p = 0.001, at 1 and 3 months, respectively). The association between regression of ventricular septum thickness and the decrease of insulin levels occurred up to the age of 1 month. CONCLUSION: There was spontaneous regression of ventricular septum thickness in children of diabetic mothers during the first 6 months of life. The association between hyperinsulinism and hypertrophic cardiomyopathy was present up to the first month of life.

[Prenatal study of hypertrophic cardiomyopathy and its association with insulin levels in fetuses of diabetic mothers]. / Estudo pré-natal da miocardiopatia hipertrófica e sua associação com os níveis de insulina em fetos de mães diabéticas.

PURPOSE: To test the hypothesis that hypertrophic cardiomyopathy during prenatal life in diabetic pregnancies is related to fetal hyperinsulinism. METHODS: Thirty seven fetuses of diabetic mothers and 28 of non-diabetic mothers were studied by echocardiography and fetal insulin levels measured. RESULTS: Mean fetal insulin levels were 22.16 (+/- 44.25) microU/ml (3.20 to 240 microU/ml) in the group with diabetes and 6.50 (+/- 3.45) microU/ml (3.10 to 17.00 microU/ml) in the control group (p = 0.004). Ten out of 37 fetuses of the diabetic group were considered to have hypertrophic cardiomyopathy (27.02%), while none of the fetuses of the control group showed increase in septal thickness (p = 0.001). A significant association between prenatal hypertrophic cardiomyopathy and fetal hyperinsulinism was demonstrated (p = 0.013). CONCLUSION: There is an association between hypertrophic cardiomyopathy and high levels of fetal insulin.

Persistent resetting of the cerebral oxygen/glucose uptake ratio by brain activation: evidence obtained with the Kety-Schmidt technique.

Global cerebral blood flow (CBF), global cerebral metabolic rates for oxygen (CMRO2), and for glucose (CMRglc), and lactate efflux were measured during rest and during cerebral activation induced by the Wisconsin card sorting test. Measurements were performed in healthy volunteers using the Kety-Schmidt technique. Global CMRO2 was unchanged during cerebral activation, whereas global CBF and global CMRglc both increased by 12%, reducing the molar ratio of oxygen to glucose consumption from 6.0 during baseline conditions to 5.4 during activation. Data obtained in the period following cerebral activation showed that the activation-induced resetting of the relation between CMRglc and CMRO2 persisted virtually unaltered for > or = 40 min after the mental activation task was terminated. The activation-induced increase in cerebral lactate efflux measured over the same time period accounted for only a small fraction of the activation-induced excess glucose uptake. These data confirm earlier reports that brain activation can induce resetting of the cerebral oxygen/glucose consumption ratio, and indicate that the resetting persists for a long period after cerebral activation has been terminated and physiologic stress indicators returned to baseline values. Activation-induced resetting of the cerebral oxygen/glucose uptake ratio is not necessarily accounted for by increased lactate production from nonoxidative glucose metabolism.

[Glycerol as a feed component in fattening pigs]. / Glycerin als Futterkomponente in der Schweinemast.

The production of motor fuel from rapeseed oil forms large amounts of glycerol as a waste product (about 100 g per kg oil). The aim of this experiment was to test glycerol as a component in diets of fattening pigs. In two experiments received 48 pigs (Pietrain x F1, Landrace x German breed) up to 30% glycerol in barley-soya bean oil meal diets. Six pigs per group with an initial weight of 32 kg (experiment 1) and 31.2 kg (experiment 2) in average received the diets semi ad libitum during the whole fattening periods. Barley was replaced by glycerol, that the content of glycerol in diets amounted 5 and 10% (1st exp.) and 5; 10; 20 and 30% in the 2nd exp. respectively. The feed intake was in order of groups up to slaughtering in exp. 1: 1.98; 2.17 and 2.23 kg DM/animal and day and in exp. 2 over 71 days: 2.26; 2.44; 2.54; 2.32 and 2.37 kg DM/animal and day. The sweet taste and the better feed structure of diets with glycerol supplementation is the reason for the higher feed intake in the groups with a glycerol supplement. The daily live weight gain was in the same order 631; 719; 754; 731; 770; 819; 704 and 598 g/animal resp. The feed conversion ratio was only in the group with 30% glycerol significant different from all other groups (3.96 against 2.95-3.30 kg DM/kg live weight gain). 30 min. after feeding the glycerol concentration in blood rose evident with higher glycerol content in diets. It was also found a higher glycerol content in the urine in dependence on the glycerol concentration in the blood. Glycerol in diets changed not the carcass yield and the meat quality. Pathological changes of liver and kidney of animals were not found after glycerol feeding. Amounts of glycerol up to 10% in the diet are recommended.