[Surgical treatment of tracheoarterial fistulas]. / Chirurgische Versorgung tracheoarterieller Fisteln.

BACKGROUND: A tracheoarterial fistula (TAF) is an uncommon but life-threatening complication after tracheostomy. Only an immediate and targeted treatment provides a chance to survive. OBJECTIVE: Surgical treatment of TAF. METHODS: Selective review of the literature and case description. RESULTS: A TAF leads to an acute bleeding complication with displacement of the respiratory tract. The mortality rate is nearly 100% without a surgical intervention. In the literature various interventional and surgical treatment procedures are described. Rapid control of bleeding via manual compression and overinflation of the tracheal cuff are the most important steps of treatment. Subsequent emergency surgery with ligation or resection of the TAF and covering of the tracheal lesion should be performed. Extracorporeal membrane oxygenation (ECMO) and a heart-lung machine can sometimes be necessary. CONCLUSION: Despite all treatment options the mortality rate of TAF remains high. The critical steps are a quick diagnosis of TAF, securing the airway and immediate bleeding control.

Evaluation of a Wellness-Based Mindfulness Stress Reduction intervention: a controlled trial.

PURPOSE: To determine if participation in a Wellness-Based Mindfulness Stress Reduction intervention decreases the effect of daily hassles, psychological distress, and medical symptoms. DESIGN: A randomized controlled trial of a stress reduction intervention with a 3-month follow-up. SETTING: A university setting in West Virginia. SUBJECTS: A total of 103 adults, with 59 in the intervention group and 44 in the control group. Eight-five percent of subjects completed the intervention. Fifty-nine percent and 61% of the intervention and control subjects completed the study, respectively. INTERVENTION: The intervention consisted of an 8-week group stress reduction program in which subjects learned, practiced, and applied "mindfulness meditation" to daily life situations. The control group received educational materials and were encouraged to use community resources for stress management. MEASURES: The Daily Stress Inventory assessed the effect of daily hassles, the Revised Hopkins Symptom Checklist measured psychological distress, the Medical Symptom Checklist measured number of medical symptoms, and a Follow-up Questionnaire measured program adherence. RESULTS: Intervention subjects reported significant decreases from baseline in effect of daily hassles (24%), psychological distress, (44%), and medical symptoms (46%) that were maintained at the 3-month follow-up compared to control subjects (repeated measures analysis of variance [ANOVA]; p < .05). CONCLUSIONS: Self-selected community residents can improve their mental and physical health by participating in a stress reduction intervention offered by a university wellness program.

A comparison of different approaches to promote community-wide dietary change.

BACKGROUND: Because public health education funds are limited, it is important to determine which methods are most effective for promoting healthy lifestyles to communities. We conducted interventions in two communities to further examine the effectiveness of various educational approaches for communicating the "1% Or Less" message to switch from high-fat (whole or 2%) to low-fat (1% or fat-free) milk. METHODS: One intervention used public relations and community-based educational activities in supermarkets, schools, worksites, and other community settings. The other used paid advertising in the absence of other programming. We used telephone surveys and supermarket milk sales data, collected before and after each campaign and in a comparison community, to determine changes in milk-usage patterns. RESULTS: After the campaign of community-based educational programs and public relations activities, the proportion of high-fat milk drinkers who reported drinking low-fat milk was 19.6% compared with 6.8% for the comparison city (p<0.0001). After the advertising-only campaign, 12.8% of high-fat milk drinkers reported drinking low-fat milk (p<0.01). Although supermarkets experienced increases in low-fat milk sales after both campaigns, the results were not statistically significant. CONCLUSIONS: The results show how well-designed public relations activities can attract news coverage and provide further evidence that such coverage can be an important component of health-promotion campaigns. Although the use of paid advertising in the absence of other media or programming appeared to change milk-drinking habits, the results were not sustained after the ads stopped airing.

Connecting brains to robots: an artificial body for studying the computational properties of neural tissues.

We have created a hybrid neuro-robotic system that establishes two-way communication between the brain of a lamprey and a small mobile robot. The purpose of this system is to offer a new paradigm for investigating the behavioral, computational, and neurobiological mechanisms of sensory-motor learning in a unified context. The mobile robot acts as an artificial body that delivers sensory information to the neural tissue and receives command signals from it. The sensory information encodes the intensity of light generated by a fixed source. The closed-loop interaction between brain and robot generates autonomous behaviors whose features are strictly related to the structure and operation of the neural preparation. We provide a detailed description of the hybrid system, and we present experimental findings on its performance. In particular, we found (a) that the hybrid system generates stable behaviors, (b) that different preparations display different but systematic responses to the presentation of an optical stimulus, and (c) that alteration of the sensory input leads to short- and long-term adaptive changes in the robot responses. The comparison of the behaviors generated by the lamprey's brain stem with the behaviors generated by network models of the same neural system provides us with a new tool for investigating the computational properties of synaptic plasticity.

Using mass media to promote healthy eating: A community-based demonstration project.

BACKGROUND: Many question whether mass media, in the absence of other programming, can produce significant and sustained behavior change. METHODS: The 1% Or Less campaign in Wheeling, West Virginia (population 35,000), used paid advertising and public relations to encourage members of one community to switch from whole or 2% milk (high-fat milk) to 1% or fat-free milk (low-fat milk). The study used a quasi-experimental research design with one intervention city and one comparison city. The effectiveness of the campaign was evaluated by collecting milk sales data from supermarkets and conducting pre- and post-intervention telephone surveys in intervention and comparison cities. RESULTS: In the intervention city, low-fat milk sales increased from 29% of overall milk sales before the campaign to 46% of sales in the month following the campaign. The increase was maintained at the 6-month follow up. According to the telephone surveys, 34.1% of high-fat-milk drinkers reported switching to low-fat milk in the intervention community compared with 3.6% in the comparison community (z = 13.1, P < 0.0001). CONCLUSIONS: A media-only approach was sufficient to encourage a significant proportion of the people in one community to alter the dietary habit targeted by the intervention.

1% or less: a community-based nutrition campaign.

OBJECTIVE: The authors evaluated the effectiveness of a community education campaign to encourage a switch from high-fat (whole and 2%) milk to low-fat (1%, 1/2%, and skim) milk as a way to reduce consumption of saturated fat. METHODS: Milk sales data were collected from supermarkets in the intervention and comparison communities for three one-month time periods: at baseline, immediately following the campaign, and six months after the campaign. In addition, trained volunteers conducted pre- and post-intervention telephone surveys. RESULTS: Overall milk sales increased by 16% in the intervention cities following the campaign and remained high at follow-up. Low-fat milk's market share increased from 18% of overall milk sales at baseline to 41% of overall milk sales in the month following the end of the campaign, an increase in market share that was sustained at the six-month follow-up. In the post-intervention telephone survey, 38.2% of those respondents who reported drinking high-fat milk at baseline reported having switched to low-fat milk. CONCLUSION: A focused message communicated through paid advertising, public relations activities, and community-based education programs increased low-fat and overall milk consumption in one community.

Physiological comparisons of two soybean cultivars differing in canopy photosynthesis. II. Variation in specific leaf weight, nitrogen, and protein components.

Cultivar differences in canopy apparent photosynthesis (CAP) have been observed in soybean (Glycine max (L.) Merr.) but little is known about the physiological mechanisms which are responsible for such differences. This study was initiated to determine if variation in ribulose 1,5-bisphosphate carboxylase (RuBPCase) and soluble protein exists among cultivars which differ in CAP during reproductive growth. In addition, the relationship between specific leaf weight (SLW) and leaf protein was examined. Two Maturity Group VI cultivars, 'Tracy' (high CAP) and 'Davis' (low CAP), were grown in the field during 1979, 1980, and 1981 and in a greenhouse experiment. Leaves located at two canopy positions (topmost, fully expanded leaf and eighth node from the top) in 1979 and three canopy positions (those mentioned, plus the fourth node from the top) in 1980 and 1981 were sampled. Leaves at the two upper canopy positions exhibited greater SLW, RuBPCase m(-2), and soluble protein m(-2) than found at the eighth node down. Photosynthetic capacity of leaves at inner canopy regions was therefore affected by both light penetration into the canopy and leaf protein status. Over the three year period, the SLW was 23 percent and the soluble protein m(-2) leaf 21 percent greater in Tracy than in Davis. Although the trend in RuBPCase m(-2) leaf was not significant, it was consistently greater in Tracy in the field and greenhouse. No cultivar differences were observed when the proteins were expressed on a unit of leaf dry weight. The quantity of RuBPCase per unit leaf area was positively correlated with SLW with significant partial correlation coefficients of 0.62, 0.67, 0.35, and 0.82 for 1979, 1980, 1981, and the greenhouse study, respectively. Since these cultivars have similar leaf area indices during September, the greater SLW of Tracy is translated into more photosynthetic proteins per unit ground area and higher CAP rate.

Wide hybridization: pollination of Zea mays L. by Sorghum bicolor (L.) Moench.

Foreign pollen tubes in the stigma of Zea mays can be prevented from reaching the ovary cavity by the unusual length of the pollen tube pathway. A simple and rapid procedure is described for overcoming this difficulty by pollinating the basal parts of the stigmas without removing the ensheathing bracts ("husks"). The method maintains high humidity in the vicinity of the ovaries, and by conserving photosynthetic tissues probably also ensures a more normal O2 /CO2 balance in the neighbourhood of the stigmas than do bagging procedures. It is shown that Sorghum pollen tubes readily reach the ovary after pollination by the method. Their presence induces some of the characteristic post-pollination effects caused by Zea pollen tubes, but they frequently also stimulate premature enlargement of the nucellus and lysis of nucellar cells. Although Sorghum tubes have been traced across the inner ovary wall, they have not been seen to enter the micropyle, and hybrid embryos have not yet been obtained.

Photosynthetic Characteristics of Portulaca grandiflora, a Succulent C(4) Dicot : CELLULAR COMPARTMENTATION OF ENZYMES AND ACID METABOLISM.

The succulent, cylindrical leaves of the C(4) dicot Portulaca grandiflora possess three distinct green cell types: bundle sheath cells (BSC) in radial arrangement around the vascular bundles; mesophyll cells (MC) in an outer layer adjacent to the BSC; and water storage cells (WSC) in the leaf center. Unlike typical Kranz leaf anatomy, the MC do not surround the bundle sheath tissue but occur only in the area between the bundle sheath and the epidermis. Intercellular localization of photosynthetic enzymes was characterized using protoplasts isolated enzymatically from all three green cell types.Like other C(4) plants, P. grandiflora has ribulose 1,5-bisphosphate carboxylase and the decarboxylating enzyme, NADP(+)-malic enzyme, in the BSC. Unlike other C(4) plants, however, phosphoenolpyruvate carboxylase, pyruvate, Pi dikinase, and NADP(+)-malate dehydrogenase of the C(4) pathway were present in all three green cell types, indicating that all are capable of fixing CO(2) via phosphoenolpyruvate carboxylase and regenerating phosphoenolpyruvate. Other enzymes were about equally distributed between MC and BSC similar to other C(4) plants. The enzyme profile of the WSC was similar to that of the MC but with reduced activity in most enzymes, except mitochondrion-associated enzymes.Intracellular localization of enzymes was studied in organelles partitioned by differential centrifugation using mechanically ruptured mesophyll and bundle sheath protoplasts. Phosphoenolpyruvate carboxylase was a cytosolic enzyme in both cells; whereas, ribulose 1,5-bisphosphate carboxylase and NADP(+)-malic enzyme were exclusively compartmentalized in the bundle sheath chloroplasts. NADP(+)-malate dehydrogenase, pyruvate, Pi dikinase, aspartate aminotransferase, 3-phosphoglycerate kinase, and NADP(+)-triose-P dehydrogenase were predominantly localized in the chloroplasts while alanine aminotransferase and NAD(+)-malate dehydrogenase were mainly present in the cytosol of both cell types. Based on enzyme localization, a scheme of C(4) photosynthesis in P. grandiflora is proposed.Well-watered plants of P. grandiflora exhibit a diurnal fluctuation of total titratable acidity, with an amplitude of 61 and 54 microequivalent per gram fresh weight for the leaves and stems, respectively. These changes were in parallel with changes in malic acid concentration in these tissues. Under severe drought conditions, diurnal changes in both titratable acidity and malic acid concentration in both leaves and stems were much reduced. However, another C(4) dicot Amaranthus graecizans (nonsucculent) did not show any diurnal acid fluctuation under the same conditions. These results confirm the suggestion made by Koch and Kennedy (Plant Physiol. 65: 193-197, 1980) that succulent C(4) dicots can exhibit an acid metabolism similar to Crassulacean acid metabolism plants in certain environments.

Distribution of Photosynthetic Enzymes between Mesophyll, Specialized Parenchyma and Bundle Sheath Cells of Arundinella hirta.

Arundinella hirta L. is a C(4) plant having an unusual C(4) leaf anatomy. Besides mesophyll and bundle sheath cells, A. hirta leaves have specialized parenchyma cells which look morphologically like bundle sheath cells but which lack vascular connections and are located between veins, running parallel to them. Activities of phosphoenolpyruvate and ribulose-1,5-bisphosphate carboxylases and phosphoenolpyruvate carboxykinase, NADP-and NAD-malic enzymes were determined for whole leaf extracts and isolated mesophyll protoplasts, specialized parenchyma cells, and bundle sheath cells. The data indicate that A. hirta is a NADP-malic enzyme type C(4) species. In addition, specialized parenchyma cells and bundle sheath cells are enzymatically alike. Compartmentation of enzymes followed the C(4) pattern with phosphoenolpyruvate carboxylase being restricted to mesophyll cells while ribulose-1,5-bisphosphate carboxylase and decarboxylating enzymes were restricted to bundle sheath and specialized parenchyma cells.

Model for variable light sensitivity in imbibed dark-dormant seeds.

The level of light-induced germination of the seed of common purslane (Portulaca oleracea L.) and curly dock (Rumex crispus L.) changes with dark incubation time prior to brief, low energy, red light treatment. The rate at which phytochrome-far red-absorbing form (Pfr) acts in the light-induced population of seeds was measured by quantitating per cent reversals of the red light effect with saturating far red light exposures at successive times after the red light exposure. A linear positive correlation was found between this rate and the final germination level. These results are compatible with a model involving changing levels, during dark incubation, of a component with which Pfr interacts. In this model, germination is initiated after attainment of a certain level of interaction between Pfr and this component. These findings also support the view that the Pfr to Pr decay rate constant and total phytochrome level are stable during dark incubation.

Polysome Formation in Light-sensitive Common Purslane Seeds.

Common purslane (Portulaca oleracea L.) seeds show light-controlled dormancy. Ribosome profiles from dark-incubated seeds consist of 22 to 26% polysomes. Light induces germination and stimulates polysome formation during the 12-hour lag period preceding radicle protrusion. Polysome levels increase to 29, 35, and 41% with exposure to 3, 6, and 9 hours of light, respectively. Although polysomes form on imbibition in the dark, 6 hours of light stimulates a significant increase in polysome formation which is probably related to early stages of radicle elongation.

Protein synthesis by isolated etioplasts and chloroplasts from pea and wheat and the effects of chloramphenicol and cycloheximide.

Etioplasts capable of incorporating (14)C-leucine into protein have been isolated from dark-grown pea and wheat plants. The requirements for leucine incorporation for etioplasts were similar to those for chloroplasts. An ATP-generating system, Mg(2+), and GTP were required. The amino-acid-incorporation activity of etioplasts from wheat was comparable to that of chloroplasts on an RNA basis, whereas the activity of pea etioplasts was about 50% of the activity of pea chloroplasts. The incorporation of leucine into protein by etioplasts and chloroplasts from pea and wheat was inhibited by chloramphenicol, and to a slight extent by cycloheximide.

Light-stimulated Production of a Chloroplast-localized System for Protein Synthesis in Euglena gracilis.

Chloroplasts and proplastids isolated respectively from autotrophic and dark-adapted cells of Euglena gracilis strain Z incorporated (14)C-l-leucine into protein. In each case the incorporation was inhibited by chloramphenicol (50% inhibition at about 5 mug/ml for chloroplasts and 30 mug/ml for proplastids), but not appreciably by cycloheximide at concentrations up to 200 mug/ml. Chloroplasts from autotrophic cells incorporated leucine into protein at rates of about 10 pg leucine per mg RNA in one minute, but isolated proplastids were only 5 to 10% as active. When dark-adapted cells were illuminated there was little increase in the activity of the chloroplast fraction during the first 12 hr. Between 12 and 24 hr, when there was a rapid increase in the rate of synthesis of chlorophyll, the capacity of the chloroplast fraction for protein synthesis increased markedly. Suppression of the formation of a chloroplast-localized system for protein synthesis by treating the cells with chloramphenicol and the lack of such an effect with cycloheximide suggests that certain of the proteins which form part of a functional chloroplast system for protein synthesis are themselves synthesized within the chloroplasts.

Identification and origin of some chloroplast aminoacyl-tRNA synthetases and tRNAs.

Light-grown, wild type Euglena gracilis contains two aminoacyl-tRNA synthetases for both phenylalanine and isoleucine. Only one of the two synthetases for each amino acid is found in isolated chloroplasts, as are the light-induced phenylalanine and isoleucine tRNAs. In each case the light-induced chloroplast tRNAs can only be acylated by the chloroplast synthetases. The chloroplast isoleucyl-tRNA synthetase is light-inducible and cannot be detected in dark-grown cells or in cells of the bleached mutant W(3)BUL. The presence of the chloroplast phenylalanyl-tRNA synthetase in W(3)BUL, which contains no chloroplast DNA or structure, indicates that this chloroplast enzyme is synthesized in the cytoplasm and is coded by nuclear genes.

The photosynthetic response to a shift in the chlorophyll a to chlorophyll B ratio of chlorella.

The chlorophyll a:b ratio was shifted in Chlorella vannielii by varying the illuminance under which the cells were cultured-the ratio increased from 2.9, 3.0, 4.0, and 4.8 to 6.2, respectively, at 100, 300, 900, 2,700 and 6,000 foot candles. The 6,000-foot candle cells retained an optimal growth rate at the chlorophyll a:b ratio of 6.2 which was the upper limit of normal growth. Comparisons were made between the 300-and 6,000-foot candle cultures to determine the significance to the photosynthetic mechanism of a shift in the chlorophyll a:b ratio.The high light cells (6,000 foot candles) contained only one-tenth the total amount of chlorophyll of the low light cells (300 foot candles) based on dry weight. The total chlorophyll per cell of the high light cells was one-fifth of that in the low light cells. Electron micrographs indicated differences in chloroplast structure. An average of five or six thylakoids composed a granum-like region of the low light chloroplasts, whereas only a pair of thylakoids at most was found in the high light chloroplasts. The high light chloroplasts had more starch. On a dry weight basis, the high light cells had a respiration rate 3 times that of the low light cells. Based on chlorophyll, the respiration rate of the high light cells was 26 times greater. Based on dry weight, the oxygen evolution for both cultures was essentially the same at 6,000 foot candles; however, at 300 foot candles the rate for the low light cells was about 5 times faster than that of the high light cells. With chlorophyll as the index, the rates of the high light cells were higher than those of the low light cells-7 times faster at 6,000 and 2 times faster at 300 foot candles. At 10,000 foot candles, the low light-grown cells underwent photooxidation, whereas the high light grown cells photosynthesized at a rate slightly higher than at 6,000 foot candles.Action spectra of system II (oxygen evolution) from a modulated polarograph indicated photochemical participation of chlorophyll b in the high light deficient cells, although the participation was much less than in the low light cells. Enhancement was 1.11 for the low light cells, and 1.05 for the high light cells.In order to account for the energy balance in the two cultures it was concluded that perhaps oxidative phosphorylation supplemented a reduced photophosphorylation in the high light cells. Experiments with peroxyacetyl nitrate support the view that cyclic photophosphorylation is less in the chlorophyll b-deficient cells. Chlorophyll b served also to broaden absorption for the photosynthetic unit-a detrimental role when cells are illuminated above saturation.