In vitro effects of urease inhibitors on rate of urea hydrolysis in soils

We studied the effect of urease inhibitors on the urea hydrolysis in some Sundanese soils belonging to the orders of Vertisol and Entisol. The hydrolysis showed a lag period of about 3 days and its rate (Y) per unit time (t) could be described by a two constants exponential equation of the general form Y = K₁t^K ₂. Statistical analysis showed that the intercept K₁ (rate of urea hydrolysis) was significantly affected by soil type rather than treatment. It seems that K₁ is associated with the soils' initial urease activity as it closely correlates with the Michaelis constant (km).The gradient, K₂, being significantly affected by soil type as well as treatment is probably associated with the induced urease activity with time and it, therefore, varied with variations in soils and treatments. Of the so-called urease inhibitors used in this study Ca(OH)₂, p-benzoquinone (PBQ) and orthophosphoric acid (OP) only PBQ reduced urea hydrolysis while the other chemicals have effects possibly related to modifying the soil pH. Inhibitor treated soils had substantial amounts of unacounted for N which was believed to be present, presumably, in the form of carbamate.Contribution from the Department of Biochemistry and Soil Science, Faculty of Agriculture, Shambat, Sudan.     

Narrative analysis of sexual etiquette in teenage magazines

Expanding on existing research on women's magazines, this essay examines the sexual etiquette developed in advice columns in magazines popular among teenage women. Over a span of 20 years, the advice has changed very little. Serving the rhetorical function of field guides and training manuals, teen magazines limit women's sociality and sexuality within narrowly defined heterosexual norms and practices. The rhetoric of sexual etiquette encourages young women to be sex objects and teachers of interpersonal communication rather than lovers, friends, and partners. Young women are being taught to subordinate self for others and to be contained.     

Political correctness and academic principles: a reply to Simpson

The author discusses Christopher Simpson's (1996) article, 'Elisabeth Noelle-Neumann's 'Spiral of Silence' and the Historical Context of Communication Theory.' He questions the relevance of biographical data for the evaluation of scientific theories and methods, and analyzes the rhetorical structure of Simpson's arguments. He concludes that Simpson's claims about the influence of Noelle's biography on her scholarly work are not grounded in evidence.     

Hemoglobin M equon beta 41 (C7) phenylalanine leads to tyrosine

A severe hemolytic crisis was observed in a 34-yr-old female of English-Irish extraction following a viral illness treated with acetaminophen. Heinz bodies and heat instability were present only during a transient hemolytic event. A challenge dose of acetaminophen caused no detectable hematologic abnormality. Structural studies of the hemoglobin during hemolysis and again after complete recovery localized the abnormality to tryptic peptide beta Tp-5, and automated sequencing of I 125-labeled beta chains indicated a replacement of phenylalanine (C7) beta 41 by tyrosine. Substitution of the next residue, phenylalanine (CD1) beta 42 by serine (Hb Hammersmith), has resulted in chronic severe Heinz body hemolytic anemia. The lack of chronic anemia in the present disorder may reflect the different relationships of beta41 and beta 42 and/or the similarities in volume and hydrophobicity of tyrosine and phenylalanine. It is suggested that substitution of tyrosine for phenylalanine in Hb Mequon may disturb the critical environment around the heme group and render it susceptible to oxidative denaturation in the presence of infections and/or drugs.     

A classification of endocervical curettings

The influence of inborn errors of metabolism on the amino acid content, the structure and growth of human hair has been studied in patients suffering from Phenylketonuria, Cystinosis, Homocystinuria and Tyrosinosis. Examiniation of hairs under the scanning electron microscope reveals defects and abnormalities such as a plicated pattern of the cuticula in patients with Phenylketonuria and Cystinosis. The amino acid content of the hydrolized hair keratin of all patients was within normal range and did not reveal significant changes of phenylalanine, cystine, homocystine, methionine or tyrosine. Disturbance in hair growth was determined by evaluation of standardized hair root samples. The results indicate an increase in hair root atrophy with increasing severity of the disorder of amino acid metabolism.     

Acute liver injury in rats by praseodymium nitrate (author''s transl)

After acute intoxication with praseodymium nitrate (10 mg/kg body weight i.v.), time functions of enzyme activities of GOT, GPT, ChE, AP and of free fatty acids concentration in rat serum were analysed and the results subjected to significance and correlation analysis. Time functions of free fatty acids concentration corresponded with those of enzyme activities of GOT and GPT. In the early state of intoxication serum concentrations of palmitoleinic and oleic acid were more increased than those of stearinic acid. There seems to be an alteration in the correlations of analysed measures with regard to their temporal changes parallel to the progress of intoxication.     

Lactate metabolism in the dog during shock from hemorrhage, cardiac tamponade or endotoxin

Serum IgE concentrations of patients with paragonimiasis were determined by a radioimmunosorbent test. The mean concentration was 3,462.3 IU/ml in a group of 13 cases of paragonimiasis miyazakii in which patients showed clinical symptoms and/or positive immunological diagnostic tests, and 1,026.6 IU/ml in a control group of 13 individuals who had eaten uncooked freshwater crabs, Potamon dehaani, but had been found to be free from the infection. Moreover, the IgE level of the pleural exudates obtained from four patients with paragonimiasis miyazakii on the day of bleeding or within several days after was significantly higher than that of their sera, ranging between 4,200 IU/ml and 10,000 IU/ml. This was true also in a case of paragonimiasis westermani. Sera and pleural exudates of patients with both forms of paragonimiasis were applied to immunosorbent columns of Sepharose 4B beads coupled with saline extracts of Paragonimus miyazakii, P. weetermani, or P. ohirai. IgE eluted from the corresponding column was considered to be specific, being around 5% to 10% of the total IgE.