The occurrence in amino acid sequences of extensive informational symmetries based on possible codon-codon complementarity in the encoding polynucleotides

1. A procedure is described for the detection and assessment of informational complementarity in an amino acid sequence; it is based on possible autocomplementarity in the mRNA, and involves codon-to-codon matching. 2. This procedure was applied to myelin basic protein, a variety of protamines, histone IV, silk fibroin, rat skin collagen alpha1 chain and a sheep keratin. A multiplicity of extensive low-probability informational symmetries, based on codon-to-codon matching, were detected. 3. These low-probability orderings, which are independent of the actual mRNA codons, are rationalized in terms of the evolutionary ordering of the amino acid sequences concerned, in such a way that constraints on the secondary structure of the coding polynucleotides were satisfied. This possible interpretation is supported by a number of significant common properties of the protein sequences analysed.     

Evaluation of an adenosine 5'-triphosphate assay as a screening method to detect significant bacteriuria

The bioluminescent reaction of adenosine 5'-triphosphate (ATP) with luciferin and luciferase has been used in conjunction with a sensitive photometer (Lab-Line's ATP photometer) to detect significant bacteriuria in urine. This rapid method of screening urine specimens for bacteriuria was evaluated by using 348 urine specimens submitted to the clinical microbiology laboratory at the University of Minnesota Hospitals for routine culture using the calibrated loop-streak plate method. There was 89.4% agreement between the culture method and the ATP assay, with 7.0% false positive and 27.0% false negative results from the ATP assay using 10(5) organisms/ml of urine or greater as positive for significant bacteriuria and less than 10(5) organisms/ml as negative for significant bacteriuria.     

A sensitive method for the determination of amitriptyline and nortriptyline in human plasma

The kinetics of the male gametogenesis during the pregonadal period, prespermatogenesis, and "early" spermatogenesis has been described in detail. Concerning spermatogenesis in the adult individual reference is made to the articles of Courot, Hochereau-de Reviers and Ortavant (1970) and of Clermont (1972). The comparison of female and male gametogenesis (Fig. 1) shows that the "gonia stage" (asterisks) of the female germ cells is limited to one proliferation wave only, whereas the "gonia stage" of the male germ cells consists of a first proliferation wave, comparable to that of oogonia, a preparative phase to initiate spermatogenesis, and a second proliferation wave with renewal and differentiation of the spermatogonia. Germ cells in the "gonia stage" are highly sensitive towards ionising radiation and cytostatic drugs.     

Bleeding fibroma of the small intestine

A case of serious, recurrent enterorrhagia is reported. The cause could not be identified with normal diagnostic tools and was discovered only after explorative laparotomy. The finding was benign ulcerated tumour of the small intestine, histologically defined as fibroma with fluorishing cellularity.     

Comparison of hemodynamic and regional blood flow changes at equivalent stages of endotoxin and hemorrhagic shock

Hemodynamic, respiratory, and regional blood flow measurements were carried out in two groups of monkeys at three roughly equivalent stages of endotoxin and hemorrhagic shock. Comparisons revealed characteristic differences at the two early stages, particularly in systemic vascular resistance and the pattern of distribution of cardiac output. However, at the final stage of shock, these patterns had merged and there were no characteristic differences between the two groups. The pathologic significance of these findings, in terms of the endotoxin theory of irreversible hemorrhagic shock and the realtive contributions of vasoactive humoral substances at various stages of the two forms of shock, is discussed.     

Morphometric study of trout gills: a light-microscopic method suitable for the evaluation of pollutant action

1. Methods are described for the morphometric estimation of parameters of the gill system of trout which are relevant to its function in gas exchange. The methods have been used with 1 mum sections viewed under the light microscope. 2. In particular the diffusion distances between water and blood are measured, which together with determinations of gill area, provide figures for the morphometrically estimated diffusing capacity. 3. The methods have been used to compare the diffusing capacity of gills from control fish and those treated in polluted waters. The concept of relative diffusing capacity (Drel) is introduced which enables comparisons to be made without the need to determine the absolute diffusing capacity. 4. Quantitative estimation of changes in relative volumes and surface areas of components of the secondary lamellae were determined, and employed to explain the possible anatomical causes of changes in Drel. 5. It is suggested that these methods can be of value in the comparison of the gills of fish treated in different waters.     

Intra-arterial sympathetic blockade in the treatment of clinical frostbite

Regional medical sympathectomy achieved by the intra-arterial injection of reserpine appeared to be of benefit in the treatment of five patients with acute or chronic frostbite injuries. Clinical improvement was associated with a significant increase in arteriographically determined regional perfusion.     

Reversal by naloxone of the effects of morphine on the unanesthetized dog]

In unasthetized dogs naloxone induced effects opposed to those of morphine (tachycardia, agitation, hyperthermia, tachypnea) and mydriasis. These effects were moderate and transient; some of them were elicited with low doses being border-line after 0.03 mg.kg-1 s.c., statistically significant after 0.1 mg.kg-1 s.c.; they increased slightly with the dose. After repeated administrations, acute tolerance developed and some moderate morphine-like effects (miosis, sedation) were observed. The stimulatory effects described here may result from antagonism of a morphinomimetic natural ligand,and represent thus indirect arguments in favour of normal functions of this ligand; these functions would be to temper not only algesic but also other stimulant reactions. The limitation of the effects might result from the limited release of this ligand in normal dogs and (or) from interfering morphinomimetic properties of naloxone, which are apparently unmasked when administrations are repeated. Both, stimulatory and inhibitory effects of naloxone are not liable to represent noticeable side-effects of this drug, but they both might play some role in the mechanisms of precipitated abstinence.     

In vitro induction of F1 hybrid anti-parent cell-mediated cytotoxicity

Spleen cells from normal (C57BL/6 X DBA/2)F1 mice were sensitized in vitro for 5 days with irradiated C57BL/6 or DBA/2 parental stimulating cells. Effector cells were generated which specifically lysed 51Cr-labeled targets (leukemia or mitogen-stimulated lymphoid cells) H-2-matched with the parental genotype used for sensitization. The response of F1 spleen cells to the C57BL/6 parent was stronger and more reproducible than that to the DBA/2 parent. The kinetics of generation of effector cells were similar for the F1 anti-parent and an F1 anti-allogeneic response. However, the magnitude of the F1 anti-C57BL/6 cytotoxic response was considerably lower than the F1 response to allogeneic cells. The ratio of responder to stimulator cells in the cultures was more critical for the former than for the latter response. Several lots of fetal bovine serum were found to be adequate for supplementing the medium in the induction of J1 hybrid anti-parent and anti-allogeneic cytotoxic effector cells. Based on these and other studies, it would appear that the F1 hybrid anti-parent cytotoxic response provides an in vitro model of murine hemopoietic graft rejection in vivo. This response may be elicited by a mechanism distinct from T cell-mediated cytotoxicity and involve different subpopulations of spleen cells.