Massive Nitrogen Research Articles

Massive nitrogen loss in critical surgical illness: effect on cardiac mass and function.

The authors measured cardiac mass and function to determine whether these changed in patients who were critically ill who were losing large amounts of nitrogen from the body. The large losses of body nitrogen that occur in patients with protein-energy malnutrition are associated with a loss of cardiac mass and function. It is not known if this also occurs in patients who were critically ill who are losing massive amounts of nitrogen. Once hemodynamically stable, 13 patients who were critically ill underwent sequential measurements of left ventricular mass (LVM) and function, total body nitrogen (TBN), total body potassium, body weight, fat-free mass, and limb muscle mass. Over a 21-day study period, there was no change in LVM or function despite falls of 14% and 21% in TBN and total body potassium, respectively, a 21% fall in limb muscle mass, and a deterioration in skeletal muscle function by approximately 40%. In patients who were critically ill, cardiac mass does not decrease and function does not deteriorate after hemodynamic stability has been achieved despite massive losses of protein from the body.

High nitrogen concentration in Fe-Cr-Ni alloys

Increasing the nitrogen concentration in iron and iron alloys significantly improves their mechanical properties. A recent technique for melting in a hot-isostatic pressure furnace using nitrogen as the pressurizing gas has been developed by United States Bureau of Mines researchers for making massive nitrogen additions to iron (up to 1.6 wt pct nitrogen) and iron-chromium-nickel alloys (up to 6.6 weight percent nitrogen). The total nitrogen concentration measured at atmospheric pressure and room temperature was determined to be the equilibrium nitrogen concentration in the molten alloy. Statistical correlations were derived to explain the effects of melt pressure and alloy composition on the resulting nitrogen concentration. Nitrogen concentrations measured in solidified alloys made by high-pressure melting technique at lower pressures are consistent with previously published data. Computer generated phase diagrams for high nitrogen-chromium concentrations are also consistent with nitride microstructure observed after high-pressure melting. Extension of existing atmospheric nitrogen concentration data to higher pressure nitrogen concentrations shows Sievert’s Law (nitrogen concentration is proportional to the square root of the nitrogen melt pressure) to be valid for pure iron. However, substantial deviations from Sievert’s Law are observed for higher alloy compositions. Statistical fits of thermodynamic concentration data to the high-pressure melt nitrogen data require evaluating element concentration terms, interaction effect terms, pressure terms, and pressure-composition effect terms. Examination of the nitrogen concentration data suggests several methods of correlation.

High Nitrogen Concentration in Fe-Cr-Ni Alloys

ABSTRACTIncreasing the nitrogen concentration in iron and iron alloys significantly improves their mechanical properties. A recent technique for melting in a hot-isostatic pressure furnace using nitrogen as the pressurizing gas has been developed by U.S. Bureau of Mines researchers for making massive nitrogen additions to iron (up to 1.6 weight percent nitrogen) and iron-chromium-nickel alloys (up to 6.6 weight percent nitrogen). The total nitrogen concentration measured at atmospheric pressure and room temperature was determined to be the equilibrium nitrogen concentration in the molten alloy. Statistical correlations were derived to explain the effects of melt pressure and alloy composition on the resulting nitrogen concentration. Nitrogen concentrations measured in solidified alloys made by high pressure melting techniques at lower pressures are consistent with previous published data. Computer generated phase diagrams for high nitrogen-chromium concentrations are also consistent with nitride microstructure observed after high-pressure melting. Extension of existing atmospheric nitrogen concentration data to higher pressure nitrogen concentrations shows Sievert's law (nitrogen concentration is proportional to the square root of the nitrogen melt pressure) to be valid for pure iron. However, substantial deviations from Sievert's law are observed for higher alloy compositions. Statistical fits of thermodynamic concentration data to the high-pressure melt nitrogen data requires evaluating element concentration terms, interaction effect terms, pressure terms, and pressure-composition effects terms. Examination of the nitrogen concentration data suggests several methods of correlation.

Role of counterregulatory hormones in the catabolic response to stress.

Patients with major injury or illness develop protein wasting, hypermetabolism, and hyperglycemia with increased glucose flux. To assess the role of elevated counterregulatory hormones in this response, we simultaneously infused cortisol (6 mg/m2 per h), glucagon (4 ng/kg per min), epinephrine (0.6 microgram/m2 per min), and norepinephrine (0.8 micrograms/m2 per min) for 72 h into five obese subjects receiving only intravenous glucose (150 g/d). Four obese subjects received cortisol alone under identical conditions. Combined infusion maintained plasma hormone elevations typical of severe stress for 3 d. This caused a sustained increase in plasma glucose (60-80%), glucose production (100%), and total glucose flux (40%), despite persistent hyperinsulinemia. In contrast, resting metabolic rate changed little (9% rise, P = NS). Urinary nitrogen excretion promptly doubled and remained increased by approximately 4 g/d, reflecting increased excretion of urea and ammonia. Virtually all plasma amino acids declined. The increment in nitrogen excretion was similar in three additional combined infusion studies performed in 3-d fasted subjects not receiving glucose. Cortisol alone produced a smaller glycemic response (20-25%), an initially smaller insulin response, and a delayed rise in nitrogen excretion. By day 3, however, daily nitrogen excretion was equal to the combined group as was the elevation in plasma insulin. Most plasma amino acids rose rather than fell. In both infusion protocols nitrogen wasting was accompanied by only modest increments in 3-methylhistidine excretion (approximately 20-30%) and no significant change in leucine flux. We conclude: (a) Prolonged elevations of multiple stress hormones cause persistent hyperglycemia, increased glucose turnover, and increased nitrogen loss; (b) The sustained nitrogen loss is no greater than that produced by cortisol alone; (c) Glucagon, epinephrine, and norepinephrine transiently augment cortisol-induced nitrogen loss and persistently accentuate hyperglycemia; (d) Counterregulatory hormones contribute to, but are probably not the sole mediators of the massive nitrogen loss, muscle proteolysis, and hypermetabolism seen in some clinical settings of severe stress.

Metabolic studies on renal homograft patients

Five renal homotransplant patients on the Metabolic Ward of the University of Colorado Medical Center were studied preoperatively and postoperatively. Nitrogen balance data accumulated on these patients indicated that azathioprine had no notable effect upon the balance. These patients were severely depleted prior to therapy. Prednisone administration resulted in an increased nitrogen excretion; however, the patients returned to a stable nitrogen balance near equilibrium despite the continued administration of rather massive daily doses of prednisone. The findings indicate that a gain in protein stores rather than continual depletion is possible even with long term massive prednisone and azathioprine therapy. Evidence is also presented that prednisone exerted a rather significant catabolic effect upon endogenous protein stores in homograft patients in addition to any anti-anabolic effect it may have exerted. Finally, it was noted that with the massive nitrogen intakes, the patients exhibited an apparent decrease in efficiency of absorption by the gastrointestinal tract. As a result, the fecal nitrogen output was found to be well in excess of normal values. Five renal homotransplant patients on the Metabolic Ward of the University of Colorado Medical Center were studied preoperatively and postoperatively. Nitrogen balance data accumulated on these patients indicated that azathioprine had no notable effect upon the balance. These patients were severely depleted prior to therapy. Prednisone administration resulted in an increased nitrogen excretion; however, the patients returned to a stable nitrogen balance near equilibrium despite the continued administration of rather massive daily doses of prednisone. The findings indicate that a gain in protein stores rather than continual depletion is possible even with long term massive prednisone and azathioprine therapy. Evidence is also presented that prednisone exerted a rather significant catabolic effect upon endogenous protein stores in homograft patients in addition to any anti-anabolic effect it may have exerted. Finally, it was noted that with the massive nitrogen intakes, the patients exhibited an apparent decrease in efficiency of absorption by the gastrointestinal tract. As a result, the fecal nitrogen output was found to be well in excess of normal values.

Massive Nitrogen Mustard Therapy in Hodgkin’s Disease with Protection of Bone Marrow by Tourniquets

Abstract 1. Eight patients with far advanced Hodgkin’s disease were treated with massive single doses of nitrogen mustard (0.95-1.5 mg. /Kg.) with tumor regression in each case. 2. An attempt was made to protect the bone marrow of the extremities from the effects of the nitrogen mustard by applying orthopedic tourniquets during the injection. There was definite evidence that the marrow was protected by this procedure. Marrow in the tibia became progressively more cellular during the time that the marrow in the torso degenerated to almost complete aplasia. During the period of recovery, radioactive iron was given and more of it localized in the protected arm than in the unprotected, evidence of greater erythropoietic activity. 3. Neurologic complications occurred at the doses employed. 4. Serious gastrointestinal pathology was not demonstrated at these doses. 5. Prior extensive radiation therapy prolonged the hemopoietic depression due to nitrogen mustard. This was not produced by previous mustard therapy. 6. Color change in ecchymotic areas may be used to predict bone marrow recovery. 7. Dividing the massive dose seems to result in less toxicity.

Metabolic changes following transection of the spinal cord in dogs.

The influence of the central nervous system on metabolism and endocrine activity as based on functional alterations following transection of the brain stem in dogs has been previously reported by Anderson and her associates (1955), The present paper continues the theme, dealing with animals which have been subjected to transection of the spinal cord. Data available oll metabolic changes in patients and experimental animals with spinal cord lesions are rather meager. Grafe (I928), a pioneer in this field, reported increased nitrogen excretion following cervical cord transection in dogs. He suggested that the nitrogen loss was due to the interruption of the temperature-regulating pathways from the higher centers to the periphery. Cooper et al. (1950) observed massive nitrogen loss in male patients immediately after severe injury had been sustained by the spinal cord at levels between the 5th cervical and the 19.th thoracic segments, and for a week or two thereafter. The negative nitrogen balance amounted to 15 to 25 gm per day. Urea nitrogen constituted 80 per cent of the total urinary nitrogen. Hypoproteinemia occurred, with serum protein levels as low as 4,6 to 5,7 gm per cent. In those cases in which the urinary creatine was determined, extremely high values were obtained; in one ease the ereatine excretion exceeded 1000 mg per 9,4 hours. In the period following the acute stage creatinuria was still present, about 800 mg per day. In this period the serum proteins increased, but did not reach normal levels. When the clinical course reached a chronic stage, a positive nitrogen balance appeared; in some eases the positive balance amounted to 5 to 7 gm daily, and the ereatinuria decreased to 100 to 9,00 mg daily. Serum protein levels often remained low even when the nitrogen balance was positive.