Arterial occlusion after cannulation.

The occurrence of ischaemic changes, arterial occlusion, and other complications which may follow percutaneous arterial cannulation was assessed in a survey of 155 patients. No patient complained of or had signs of ischaemic damage though signs of arterial occlusion were found in 33 patients (22%). These signs were significantly more common after periods of cannulation greater than six hours (43%) than after less than six hours cannulation (17%). During recovery from occlusion all patients had palpable pulsation over the artery even though blood flow seemed to be absent. By the end of follow-up blood flow had returned in 19 of the 33 occluded arteries.     

Metabolic changes in dogs during anaphylactic shock.

Hemodynamic and metabolic parameters were studied in conscious dogs during anaphylactic shock. Mean arterial blood pressure and cardiac output decreased and heart rate increased during shock. FFA flux and O₂ consumption decreased significantly shortly after the challenging injection. RQ was elevated indicating a shift in metabolite utilization towards carbohydrates.     

Metabolic changes in rice seedlings with different submergence tolerance after desubmergence

When flash flood intolerant rice cultivars are submerged, they show greater morphological changes such as elongation and chlorosis than tolerant cultivars. These morphological responses are caused by ethylene produced during submergence, however, a visible damage of intolerant cultivars is markedly developing after desubmergence rather than during submergence, which is probably due to oxidative damage. We studied the effect of ethylene produced during submergence on antioxidant content and oxidative damage after desubmergence. When rice (Oryza sativa) was submerged for 8 days, both tolerant cultivar (BKNFR) and intolerant cultivars (Mashuri and IR42) showed a decrease in ascorbate concentration during submergence. After 3 days of desubmergence, the tolerant cultivar showed a rapid recovery of total ascorbate and ascorbic acid, whereas intolerant cultivars showed a slow recovery of them, an increase in malondialdehyde formation, and low survival rate (about 30%). However, applying 200 mg l⁻¹ of AgNO₃ as an ethylene antagonist to intolerant cultivars suppressed the decrease in ascorbate and the increase in malondialdehyde formation after desubmergence, and improved survival rate to about 60%. Ascorbic acid supply to leaf discs from submerged IR42 suppressed increase in malondialdehyde formation by incubation under the light for 24 h. In addition, strong negative correlations were observed between malondialdehyde formation with ascorbate concentration (r=−0.93) and with percentage of survival (r=−0.98). Our results indicate that the accumulated ethylene during submergence adversely affected antioxidant mechanism in intolerant rice cultivars after desubmergence, and ascorbic acid was an important antioxidant in vivo for the recovery of submerged rice seedlings.     

Metabolic changes in rats during developing thiamin deficiency.

Determinations of rectal temperature, blood glucose, plasma free fatty acids, liver acetyl-CoA and carcass fat of thiamin-deficient rats indicated that during the ensuing anorexia they metabolized their fat reserves more rapidly than did pair-fed normal controls. Their lower metabolic rate indicates that the reserves mobilized are utilized inefficiently.     

Delayed results after implantation of bifurcated prosthesis in aorto-iliac incompetence]

Early results and those seen after a 5-year follow up are discussed. Three hundred fifty one patients with aortoiliac incompetence were treated with the implantation of bifurcated aortoiliac prosthesis. Very favourable early result was achieved in 284 (81%) patients. Very favourable delayed effect was noted in 133 patients, i.e. in 75% of patients who reported for the control examination. In the follow up period, amputation of the limb was performed in 30 (8.5%) patients because of progressing ischemia. Hundred thirty seven (39%) followed up patients died during 5 years. Causes of so high mortality rate are discussed in view of risk factors and postoperative complications.     

Histological changes in skeletal muscle after temporary independent occlusion of arterial and venous supply

In both replantation and transplantation, circulation is restored to ischemic muscle by vascular anastomoses. As a result, the length of time that skeletal muscle will endure ischemia is important to know clinically. Using microsurgical techniques, we shut off the blood supply to the quadriceps femoris muscle in adult Wistar rats--by occluding the artery, the vein, or both for varying time intervals. The muscle was maintained in the animal for 48 hours, and then examined histologically. Our results indicate that the period of warm ischemia should be limited to about one hour, because a longer period of arterial ischemia produces severe histological changes in muscle. The limiting factor seems to be the arterial, rather than the venous supply. The possibility of muscle regeneration after such ischemic insults was not investigated.     

Metabolic changes in tomato fruits and seeds after viral, bacterial and fungal infections

The metabolic changes in tomato fruits and seeds separately infected with cucumber mosaic virus, Pseudomonas syringae pv. tomato or Botrytis cinerea were investigated cytochemically. The changes of peroxidase (E.C. 1.11.1.7) and β-glucosidase (E.C. 3.2.1.21) were investigated biochemically as well. Tomato fruits were involved in the study because of their high economic value. Tomato seeds were investigated since they have been used most extensively as a model system for studying the physiology and biochemistry of seed development. The diseases caused by the pathogens under study are of special importance for yield reduction in tomato. The three pathogens provoked local changes in the activities of enzymes under study that affect the infected pericarp tissues and neighboring seeds. It was established non-specific and specific responses. The non-specific responses of invaded tissues were expressed as a local enhancement of peroxidase activity in both pericarp tissues and seeds as well as a decrease in activities of: i. enzymes taking part in aerobic and anaerobic respiration, ii. hydrolases esterase and acid phosphatase involved in the basic metabolism as well as an enhancement of their activities in neighboring tissues. Furthermore, it was observed an enhancement of α-galactosidase activity in infected area was observed. The specific responses depending on the type of the pathogen consisted in an enhancement of glucose-6-phosphate dehydrogenase activity by virus infection and an increase of β-glucosidase activity by fungal invasion.     

Metabolic changes in soybean nodules after inhibition of nitrogen fixation by treatment with oxygen

Metabolites that accumulated in soybean [Glycine max (L.) Merr.]nodules after inhibition of nitrogen fixation were analysedto determine what carbon compounds the bacteroids might obtainfrom their host. Exposure of roots of intact soybean plantsto 100% O₂ for 5 min caused a decrease in acetylene reductionactivity within 10 min and then the activity recovered onlyslowly. Analysis of carbohydrates, organic acids, volatile compoundsand amino acids in extracts of nodules revealed that succinate,malate and alanine all accumulated within 10 min after treatmentwith O₂. The concentrations of sucrose, acetone, tyrosine, valine,isoleucine, leucine, and ornithine in the nodules increasedslowly after such treatment. The results are discussed in termsof carbon sources for supporting nitrogen fixation of soybeanbacteroids. Key words: Glycine max, carbon metabolism, nitrogen fixation, nodules     

Metabolic changes in some acclimation phenomena

Summary 1. Acclimation to constant cold also causes in mice a decrease in the intensity of muscle shivering in cold and an increase in the metabolic rate of the animal and in the succinic dehydrogenase complex activity in the liver and skeletal muscles.2. The succinic dehydrogenase complex activity in the liver depends on the acclimation temperature at least over a range from 5° to 32° C.3. Acclimation of mice to short-term exposures to cold does not affect metabolic rate of the animals or the succinic dehydrogenase complex activity in the liver but causes an increase in the metabolic response to injected l-noradrenaline.4. The induced tolerance to the hypothermisant effect of promazine in mice develops slower in a thermoneutral environment than at room temperature.

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Stoffwechselveränderungen bei einigen Akklimatisierungsphänomenen

Kurzfassung Schon in früheren Untersuchungen wurde nachgewiesen, daß die Akklimatisierung von Ratten an konstante niedrige Temperaturen von stoffwechselphysiologischen Veränderungen im Bereich der Zellen begleitet werden. Nach unseren Untersuchungen verursacht Anpassung an konstante niedrige Temperaturen auch bei Laboratoriumsmäusen eine Abnahme der Intensität des Muskelzitterns in der Kälte, einen Anstieg der Stoffwechselrate des Tieres sowie der Aktivität des Sukzinodehydrogenase-Komplexes in Leber und Skelettmuskeln. Die Sukzinodehydrogenaseaktivität in der Leber männlicher Mäuse zeigt eine Abhängigkeit von der Anpassungstemperatur, zumindest über den Bereich von 5° bis 32° C. Mäuse können ferner daran angepaßt werden, daß sie wirksamer auf kurzfristige Kälteeinwirkungen reagieren. Derartige Anpassungen beeinflussen jedoch nicht die Stoffwechselrate oder die Aktivität des Sukzinodehydrogenase-Komplexes in der Leber, sondern verursachen eine gesteigerte stoffwechselphysiologische Reaktion auf injiziertes 1-Noradrenalin. Die induzierte Widerstandsfähigkeit gegenüber der temperatursenkenden Wirkung des Phenothiazinderivates Promazin entfaltet sich bei Mäusen in einer thermoneutralen Umgebung langsamer als bei Zimmertemperatur. Dieser Umstand deutet auf Ähnlichkeiten hin, welche bei den ersten Stadien der Promazintoleranz und der Akklimatisierung an kurzfristige Kälteeinwirkungen bestehen.

     

Metabolic adaptations to training precede changes in muscle mitochondrial capacity.

To determine whether increases in muscle mitochondrial capacity are necessary for the characteristic lower exercise glycogen loss and lactate concentration observed during exercise in the trained state, we have employed a short-term training model involving 2 h of cycling per day at 67% maximal O2 uptake (VO2max) for 5-7 consecutive days. Before and after training, biopsies were extracted from the vastus lateralis of nine male subjects during a continuous exercise challenge consisting of 30 min of work at 67% VO2max followed by 30 min at 76% VO2max. Analysis of samples at 0, 15, 20, and 60 min indicated a pronounced reduction (P less than 0.05) in glycogen utilization after training. Reductions in glycogen utilization were accompanied by reductions (P less than 0.05) in muscle lactate concentration (mmol/kg dry wt) at 15 min [37.4 +/- 9.3 (SE) vs. 20.2 +/- 5.3], 30 min (30.5 +/- 6.9 vs. 17.6 +/- 3.8), and 60 min (26.5 +/- 5.8 vs. 17.8 +/- 3.5) of exercise. Maximal aerobic power, VO2max (l/min) was unaffected by the training (3.99 +/- 0.21 vs. 4.05 +/- 0.26). Measurements of maximal activities of enzymes representative of the citric acid cycle (succinic dehydrogenase and citrate synthase) were similar before and after the training. It is concluded that, in the voluntary exercising human, altered metabolic events are an early adaptive response to training and need not be accompanied by changes in muscle mitochondrial capacity.     

Exercise training improves endothelium-mediated vasorelaxation after chronic coronary occlusion.

The present study evaluated combined effects of chronic coronary occlusion and exercise training on endothelial function. Gradual occlusion was produced by placement of an ameroid constrictor around the proximal left circumflex (LCX) coronary artery of female swine. Two months after placement of the ameroid, animals were restricted to their pens or exercise trained for 16 wk. Epicardial arteries (>500 microm ID) were isolated from the collateral-dependent LCX coronary artery distal to the occlusion and the nonoccluded left anterior descending (LAD) coronary artery. Bradykinin- and ADP-mediated relaxation of LCX and LAD coronary arteries was enhanced after exercise training. Inhibition of nitric oxide synthase with N(G)-nitro-L-arginine methyl ester decreased bradykinin- and ADP-mediated relaxation in LCX and LAD myocardial regions. Importantly, combined inhibition of effects of endothelium-derived hyperpolarizing factor with increased extracellular K(+) (20-30 mM) and nitric oxide synthase completely abolished coronary LAD and LCX relaxation to bradykinin. Our data indicate that exercise training improves endothelium-mediated relaxation of arteries isolated after chronic coronary artery occlusion, likely as a result of enhanced production of nitric oxide and endothelium-derived hyperpolarizing factor.