Advanced emphysema with bronchitis is associated with significant weight loss and malnutrition, the true cause of which has not been clearly identified. The purpose of this exploratory study was to compare plasma amino acids and related compounds and catecholamines in a group of patients with advanced end-stage emphysema with a control group of similar age and sex in an effort to further understand this malnourished state. Fasting blood samples were obtained by venipuncture after a rest period. Plasma amino acid levels were determined by ion exchange high pressure liquid chromatography with fluorometric detection. Plasma catecholamines were determined by radioenzymatic analysis. Anthropometric measurements, the usually accepted biochemical markers of nutrition, dietary analysis, pulmonary function tests, and a historical analysis of the state of health including drug use and smoking history in each subject were analyzed. Ages and heights were comparable, whereas weights were significantly decreased in the patients with emphysema. Total serum protein and serum albumin values were significantly lower in the patient group. Significant respiratory muscle weakness was indicated by reduced negative inspiratory force in these end-stage patients, contrasting with well-preserved muscle strength usually found in obstructive lung disease. The dietary caloric intake of the patients was comparable to that of the control subjects. We conclude that the fine balance of the amino acid pool in patients with bronchitis and emphysema is well preserved, except for significant elevations of aspartic acid, glutamine, and cystine, and a decreased level of leucine. In addition, norepinephrine levels were significantly increased. Weight loss in patients with emphysema and bronchitis is likely due to increased energy demands related to hypermetabolism.
2,2,2-Trifluoroethanol (TFE)-water is a convenient solvent for the precise conductometric measurement of solvolysis rates. A comparison of results in TFE-water with those in ethanol-water gives a useful indication of the role of changing nucleophilicity in solvolysis reactions. It has been found that the a-and /3-deuterium effects in 1-phenylethyl chloride, which in ethanol-water are at or near a maximum characteristic of a limiting reaction, are not much changed in TFE-water. However, for /-butyl-d» chloride the isotope effects are larger in TFE solutions than in ethanol-water. This is explained on the basis of the incursion of some rate-determining elimina-
A substantial writing assignment in an organic chemistry course provides a means of allowing students to direct their own learning about a specific application of organic chemistry. The use of peer review provided additional benefits: students learned organic chemistry from reading each others' papers and learned more about how classmates write about chemistry. Recommendations about how best to collaborate with a librarian in the design of a writing assignment that involves substantial library research are presented. One of the main features of effective assignments is the statement of clear expectations about assessment of the writing. The explicit criteria used to grade the papers are described. A substantial writing assignment such as this one can provide a means of moving an organic course from instructor-centered to student-centered.
Arginine (ARG) was injected (0.8 g/kg, i.p.) into rats and levels of ARG were determined in plasma and four brain areas in the morning and afternoon. In control rats, brain values for ARG and some amino compounds are lower in the afternoon than in the morning. After ARG administration, ARG levels increase about 10-fold in the plasma and 2- to 3-fold in the brain areas. Brain ARG levels follow plasma levels. Elevated ARG levels affect a number of related amino compounds both in the plasma and all brain areas most notably ornithine, phosphoserine, glycine, GABA and ammonia. An increase of citrulline after ARG administration suggests the possibility of ARG-stimulated nitric oxide formation in the midbrain. Thus, ARG shows a daily rhythm in the plasma and brain and its administration increases ARG brain levels which seem to follow plasma levels. In addition, ARG alters a number of other amino compounds most notably GABA, glycine, ornithine and ammonia, indicating that some pharmacological effects seen after ARG administration might be caused by elevated levels of ARG and/or changes in other amino compounds.
The constituents of bronchoalveolar lavage (BAL) fluid have been shown to reflect the presence and possible etiology of several pulmonary diseases. Presently, although research studies have reported the concentrations of cytokines and compounds such as major basic protein in BAL fluids, only the cellular elements, total protein, albumin, and immunoglobulins have been well defined. We hypothesize that amino acids and related amino compounds, well known participants in physiologic and biochemical processes, are present in BAL fluid and may have involvement in asthma. Our objective was to extend knowledge of the total chemical profile and clinical value of BAL fluids in humans by measuring these amino compounds in normal control subjects and asthmatic patients. Analysis by high-pressure liquid chromatography revealed the presence of 25 compounds. A few compounds in control subjects and patients were found to have values > 1.0 nmol/ml, while the majority were present in comparatively low concentrations < 1.0 nmol/ml. Asparagine, phosphoethanolamine, and taurine were significantly increased in the asthmatic patients. We conclude that the present profile of amino acids and related amino compounds in BAL fluid serves as a potential diagnostic tool in the study of various pulmonary disorders. The significance of increased asparagine, phosphoethanolamine, and taurine in the asthmatic patients is discussed and deserves further study.
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