Lymphangiography: Its Practical Value in Surgically Staged Patients with Hodgkin's Disease

Since the introduction of “staging laparotomy” (to determine the disease''s stage) in assessing Hodgkin''s disease, some observers have argued that lymphangiography could be safely omitted in the initial diagnostic evaluation.To test these opinions a series of 75 patients with Hodgkin''s disease who had a staging laparotomy and histological correlation with lymphangiograms was reviewed. Of 16 examinations with positive results, one proved to be a false positive. Of the 14 examinations with equivocal results, one proved histologically positive. In the remaining 45 lymphangiograms, five were falsely negative. In all five of these patients abdominal lymph nodes were involved, but in areas that do not routinely opacify on lower extremity lymphangiography. The overall accuracy was 90 percent.Therapeutically, the lymphangiogram permits accurate planning for treatment by radiation therapy so that all known disease is treated and yet bone marrow is not excessively irradiated. Changes in lymph node architecture after therapy provide valuable information as to regression of the disease or signs of its early recurrence.     

Degradation of polysaccharides containing uronic acid residues

A method for the selective degradation of polysaccharides containing uronic acid residues is described. It involves methylation of hydroxyl and carboxyl groups, base-catalysed elimination, and mild hydrolysis with acid. The degraded product is etherified with trideuteriomethyl or ethyl groups and hydrolysed, and the resulting mixture of etherified sugars is analysed, as the alditol acetates, by g.l.c.—m.s. Comparison of this analysis with the methylation analysis of the original polysaccharide gives information on the nature of the sugar residues on either side of the uronic acid residue.     

Metabolism of Glutamic Acid and N-Acetylglutamic Acid in Leaf Discs and Cell-free Extracts of Higher Plants

Radioactive glutamic acid and N-acetylglutamic acid have been incubated with normal and wilted leaf discs and radioactivity recovered in uncombined proline. The discs which had been placed under moisture stress incorporated considerably more label in uncombined proline than did normal discs.     

Isolation and structural determination of 13 flavonoid glycosides in Hibiscus esculentus (okra)

Eleven flavonol glycosides and two anthocyanins, only one of which was previously identified, were isolated from the flower petals of okra, Hibiscus esculentus L. On the basis of chromatographic, spectral, and degradative evidence, the following structural assignments were made: quercetin 4′-glucoside, quercetin 7-glucoside, quercetin 5-glucoside, quercetin 3-diglucoside, quercetin 4′-diglucoside, quercetin 3-triglucoside, quercetin 5-rhamnoglucoside, gossypetin 8-glucoside, gossypetin 8-rhamnoglucoside, gossypetin 3-glucosido-8-rhamnoglucoside, cyanidin 4′-glucoside, and cyanidin 3-glucosido-4′ glucoside. Some evidence was obtained of a pentahy-droxy, monomethoxy-flavone glycoside. The total flavonoid content in the red portion of the petal was 0.48% of fresh weight; that in the white portion was 2.51%. The two anthocyanins comprised 28.5% of the flavonoid content of the red flower but only a trace of the content of the white.     

Methods of detection and estimation of rhizobia in soil

Summary The plant-infection technique for the estimation of rhizobia, in which small-seeded hosts are grown on agar within test-tubes, is applicable to soils with a moderate rhizobial population (in the order of at least 100/g). Account might have to be taken of skips (less diluted: negative, when more diluted are positive) likely to result, at least in part, from unfavourable conditions for rhizobial survival, multiplication or nodulation. Because of such effects, a sparse population (in the order of (10/g) may not be detected even without dilution (1 g soil per plant tube). Localisation of rhizobia in the soil is likely to be important in determining contact with the plant roots in the dilution count and in sampling from the field. Difficulties with sparsely populated soils can be partly overcome by carefully conducted direct sowings of sterilised seed, preferably in the confines of cores, either left in the field or brought back to the glasshouse.     

Ventricular septal defect with bidirectional shunting: Mathematical considerations

Previously proposed formulae for the quantitative estimation of bidirectional shunts across ventricular septal defects require determination of the oxygen contents of mixed venous, pulmonary artery, pulmonary venous, and aortic blood. Because these formulae do not take into account the mixing of oxygenated with unoxygenated blood within the ventricles, their use must result in underestimation of shunt flows in each direction. A mathematical model for a ventricular defect is examined, in which it is assumed that mixing of blood occurs in each of six sites in the venae cavae or right atrium, right ventricle, pulmonary artery, left atrium, left ventricle, and aorta. A total of fourteen streams of blood can flow from one to another of these mixing sites. As long as complete mixing occurs in the six specified mixing sites, any degree of mixing or non-mixing of the various streams is permitted. From the equations characterizing the model, formulae are derived in which the shunt flow in each direction is expressed in terms of the oxygen contents in the six mixing sites and the fractions of blood which enter the shunt from either side without prior mixing in a ventricular mixing site. The previously reported formulae, which apply when no ventricular mixing is allowed to occur, lead to theoretical minimum values for the shunt flows in each direction. At the opposite extreme where all the shunting blood is required to mix in a ventricle before entering the shunt, formulae for maximum possible shunt flows are also obtained. The absolute values for the left-to-right and right-to-left shunt flows, which must lie somewhere between the theoretical maximum and minimum values, cannot be computed from blood gas data alone. This work was supported in part by grant HE-07563 from the National Heart Institute of the National Institutes of Health and grants-in-aid from the American and North Carolina Heart Associations and the Life Insurance Medical Research Fund. Work completed during tenure as U.S.P.H.S. post-doctoral fellow.     

A novel succinyl dipeptide stimulates directed cell migration by modulating protein kinase C activity

In determining the mechanism of the chemokinetic action of the thiol protease inhibitor, E-64, in endothelial cell monolayers subjected to wounding, we synthesized succinyl-leucyl-agmatine (SLA), an analogue of E-64 that lacked the epoxy group and protease inhibitory effect. We observed that this analogue retained its chemokinetic effect on wounded endothelial cells. Its stimulatory action on endothelial cell polarization response to wounding was rapid and associated with directed cell migration. Furthermore, its effect on cellular polarization was blocked by protein kinase C (PKC) inhibitors and mimicked by pharmacologic agents that stimulated PKC activity. To determine if SLA's chemokinetic action was mediated by protein kinase C activation, we compared the effects of SLA and the tumor promoter phorbol myristate acetate (PMA) on the translocation of PKC activity in endothelial cells. We observed that both SLA and PMA induced the translocation of PKC activity from the cytosolic to the particulate fraction of the cells. We also observed that both SLA and PMA induced the phosphorylation of two proteins (Mr 23.4 and 36.5 kDa) in intact 32P-labeled cells. Thus, SLA stimulates the endothelial cell locomotor response to wounding by stimulating PKC activity.