Expression of interleukin-2 receptor on blood lymphocytes stimulated with allogeneic lymphocytes or autologous tumor cells

Summary The kinetics of interleukin-2 receptor (IL-2R) expression and the [³H]dT incorporation of blood lymphocytes after the first and the second stimulation with allogeneic leukocytes (primary and secondary MLC) or with the autologous tumor cells (primary and secondary MLTC) were compared. The expression of IL-2R paralleled the induction of DNA synthesis. The proportion of IL-2R⁺ cells of the unprimed donors peaked earlier in the secondary MLC as compared to the primary MLC (on days 3 and 5 respectively). In MLC of alloimmunized healthy individuals and in the MLTC of cancer patients the highest proportions of IL-2R⁺ cells were detected between days 2 and 3 after both the first and second stimulations. Thus the first in vitro stimulation in the MLTC showed similar kinetics to those of the secondary MLC of unprimed individuals and to the primary MLC response of the allo-immunized individuals. The findings in the MLTC substantiate the hypothesis that cancer patients can be sensitized to their own tumors. The kinetics of the appearance of the IL-2R together with the characteristics of the IL-2-propagated cultures provide useful information for the strategy of expansion of auto-tumor reactive lymphocyte populations.     

Tissue architectural features for the grading of prostatic carcinoma

In research for the development of a computer-aided workstation for the objective grading of prostatic carcinoma, tissue architectural (histometric) features were analyzed in ten cases each of well-differentiated, moderately differentiated and poorly differentiated carcinoma (as subjectively graded by the consensus of a panel of experts). Sections were cut at 4 microns, stained by the Feulgen reaction and digitized by two different video-based photometric systems. Some images were interactively segmented, considering the histometric clues to be studied; others were automatically segmented by an expert system-guided technique. The latter procedure produced good results, with over 90% of the nuclei judged to be correctly segmented in 64% of the fields studied and over 80% in another 24% of the fields. While the number of nuclei per field provided some separation of well-differentiated from other lesions, the number of nuclei per gland distinguished between well-differentiated and moderately differentiated lesions. Simplicial decomposition of the images also provided a measure of the degree of differentiation, as did the "texture" of the nuclear placement, based on two run-length statistics. Combination of the run-length features distinguished the three categories of lesions with statistical significance. The results of this study provided insights into the problems (such as the effect of field boundaries) faced in the design of an computer-aided grading system. They also showed the value of expert system-guided scene segmentation and of such histometric features as the field cellularity and the number of nuclei per gland for the discrimination between lesions of different grades of differentiation.     

Karyometric marker features in fine needle aspirates of invasive follicular carcinoma of the thyroid.

Karyometric measurements were performed on fine needle aspirates of clearly identifiable tumor areas and adjacent normal-appearing areas in the surgical specimens from ten patients with invasive follicular carcinoma of the thyroid. Similar measurements were performed on aspirates from nine patients free of thyroid disease (controls). A total of 95 karyometric features were evaluated for each nucleus. Analysis of variance of optical density values indicated (1) a similarity between tumor and normal-appearing nuclei from carcinoma cases, (2) a significant difference between those nuclei and control nuclei and (3) that most of the differences were due to the differences of tissue origin. Stepwise linear discriminant analysis selected ten features that produced a statistically highly significant separation of tumor nuclei from control nuclei. A similar analysis selected six features that produced a statistically highly significant discrimination of normal-appearing nuclei from control nuclei; the validity of those karyometric features as markers of malignancy in normal-appearing nuclei from tissues adjacent to invasive follicular carcinomas of the thyroid was demonstrated by analysis in further training and control sets of nuclei. This analysis in thyroid aspirates identified more marker features than did a previous similar analysis using tissue sections.     

Crystal structure of the cytokine interleukin-1 beta.

The crystal structure of human recombinant interleukin-1 beta has been determined at 3.0 A resolution by the isomorphous replacement method in conjunction with solvent flattening techniques. The model prior to refinement has a crystallographic R-factor of 42.3%. The structure is composed of 12 beta-strands forming a complex network of hydrogen bonds. The core of the structure can best be described as a tetrahedron whose edges are each formed by two antiparallel beta-strands. The interior of this structure is filled with hydrophobic side chains. There is a 3-fold repeat in the folding of the polypeptide chain. Although this folding pattern suggests gene triplication, no strong internal sequence homology between topologically corresponding residues exists. The folding topology of interleukin-1 beta is very similar to that described by McLachlan (1979) J. Mol. Biol., 133, 557-563, for soybean trypsin inhibitor.     

Glycogen synthesis via the indirect gluconeogenic pathway in the periportal and via the direct glucose utilizing pathway in the perivenous zone of perfused rat liver

The isolated liver from 24 h fasted rats was perfused in a non-recirculating manner in the ortho- and retrograde direction with erythrocyte-containing (20% v/v) media to provide adequate oxygenation of the liver. Glucose and/or gluconeogenic precursors were added as substrates. Glycogen formation was determined biochemically and demonstrated histochemically. With glucose as the sole exogenous substrate glycogen was deposited in the perivenous area, with gluconeogenic precursors it was formed in the periportal zone during ortho- and retrograde flow. When glucose and gluconeogenic compounds were offered together, glycogen was deposited in both zones. The results corroborate the model of metabolic zonation predicting that periportal glycogen is synthesized indirectly from gluconeogenic precursors while perivenous glycogen is formed directly from glucose.     

Physiological control and process kinetics of clavine alkaloid production byClaviceps purpurea

Summary Kinetic parameters of production of clavine alkaloids were evaluated in twoClaviceps purpurea strains. Mutagenesis brought about enhanced resistance of the biosynthetic system towards alkaloids. Addition of glucose into the fermentation medium altered the zero order kinetics of production to activation-inhibition kinetics. The glucose treatment allowed performance of both elymoclavine-inhibitionless and clavine alkaloid-decompositionless fermentations if a combination of fermentation and separation units in a closed loop was used.Nomenlacture k ₁ rate constant of agroclavine synthesis (mg Agro · mg Elymo/l·g DW·day for stage 1, mg Agro/g DW·day for stage 2) - k ₂ parameter describing inhibition of agroclavine formation rate by elymoclavine (mg Elymo/l) - k ₃ specific rate of agroclavine decay (l/g DW·day) - k ₄ maximal specific rate of elymoclavine synthesis (stage 1, 1/g DW·day, stage 2, mg Elymo/g DW·day) - k ₄ ^– maximal specific rate of elymoclavine synthesis in stage 1 (inhibition-activation mechanism) (mg Elymo/g DW·day) - k ₅ physiological constant describing the elymoclavine decay rate (l²/g DW·day·mg Elymo) - k ₅ ^– physiological constant describing the activation of elymoclavine biosynthesis by elymoclavine (mg Elymo/l) - k ₆ physiological constant describing the repression of elymoclavine biosynthesis by elymoclavine (mg Elymo/l) - k ₇ maximal specific growth rate (1/day) - k ₈ specific rate of biomass decay (l/g DW·day) - A agroclavine concentration (mg/l) - E elymoclavine concentration (mg/l) - r _A specific rate of agroclavine biosynthesis (mg Agro/g DW·day) - r _E specific rate of elymoclavine biosynthesis (mg Elymo/g DW·day) - r _i specific rate of alkaloid biosynthesis (mg alkaloid/g DW·day) - X dry biomass concentration (g/l) - specific growth rate (1/day) Abbreviations Agro agroclavine - Elymo elymoclavine - Chano chanoclavine - DW dry weight of biomass     

The combined effects of dopamine (DA) and the DA antagonists EGYT-2509, chlorpromazine and haloperidol on the kidney function

In anaesthetized dogs renal function was investigated in four successive 20-min periods in four experimental series. (1) In the first series following the first period (serving as control) 2.5 micrograms/kg/min of dopamine (DA) dissolved in 0.5 ml/min of Ringer's solution was infused into the left renal artery (period 2), than during periods 3 and 4. It was found that first (period 2) and second (period 3) doses of DA induced a significant decrease of about 20-30% in renal vascular resistance, and an increase of about 15-25% in renal blood flow. At the same time, systemic arterial blood pressure fell by 10%. The other investigated parameters of the left kidney (Cinulin, CPAH, sodium, potassium and water excretion) did not differ from the respective parameters of the intact right kidney. (2) In the second experimental series following the first period (prior to period 2) 1.0 mg/kg of the DA antagonist EGYT 2509 was administered intravenously. Prior to the period 3 again 1.0 mg/kg of EGYT 2509 and prior to period 4 2.0 mg/kg of EGYT 2509 was given intravenously. During periods 2 through 4 2.5 micrograms/kg/min of DA was infused into the left renal artery. It could be ascertained that EGYT 2509 abolished the renal effects of DA while not inducing any decrease in arterial blood pressure. (3) In the third experimental series, following the control period, prior to periods 2,3 and 4, 1.0 mg/kg, 1.0 mg/kg and 2.0 mg/kg chlorpromazine respectively, was administered i.v. followed by the infusion of DA into the left renal artery. After the administration of chlorpromazine arterial blood pressure and renal vascular resistance fell concomitantly and DA failed to induce any further changes in these parameters. According to our experiments chlorpromazine abolishes the effect of DA on kidney function. (4) In the fourth series, prior to DA infusion the dogs were given 0.5 mg/kg (period 2) then again 0.5 mg/kg and finally 1.0 mg/kg of haloperidol intravenously. Haloperidol decreased arterial blood pressure as well as renal vascular resistance, thus renal blood flow did not change. Renal blood flow could then be increased by DA infused into the left renal artery. It seems that haloperidol could not abolish the vascular effects of DA in the kidney. Our experiments indicate that substance EGYT 2509 possesses the most marked dopaminergic antagonistic effect, chlorpromazine had also been effective, while haloperidol had proved to be practically ineffective.     

The effect of pentylenetetrazol on the metacerebral neuron of Helix pomatia

The effects of Pentylenetetrazol (PTZ) on the metacerebral giant cell (MCC) of the snail, Helix pomatia were studied. Actions on membrane resistance, time constant, resting and action potentials, outward and inward ionic currents were examined. Superfusion with PTZ in concentrations of 25 to 50 mmol/l, induced a gradually evolving convulsive state, which could be studied by intracellular recording from the MCCs. In the pre-convulsive state an acceleration of the spontaneous activity developed and was followed by paroxysmal depolarization shifts (PDSs), in the convulsive phase. PTZ prolonged the membrane time constant by about 10 percent, but this could not be traced back to alterations in membrane resistance or capacity. The resting membrane potential was not significantly altered; the action potentials were prolonged by slowing down of both the rising and decaying phases. The outward potassium currents were repressed by PTZ in a voltage dependent manner. The decrease of the IA current became more pronounced at increasingly positive command pulses, while IK was relieved from depression especially at longer pulse durations. Inward currents were isolated with the aid of suppression of outward currents by 50 mmol/l TEA. Under these conditions sodium currents, measured in calcium deficient Ringer solution were moderately depressed, while the calcium currents, examined during sodium-free superfusion, were mildly enhanced by PTZ. It is concluded that PTZ effects on ionic conductances, on membrane parameters, on the resting potential and ionic currents explain only modifications of spike potentials occurring in the convulsive state and do not account for the PDS, the central phenomenon of the convulsive electrographic activity, at least in this thoroughly examined type of neuron.     

Calcium-Independent Release of Acetylcholine from Electric Organ Synaptosomes and Its Changes by Depolarization and Cholinergic Drugs

Chemiluminescent detection was applied to measure the continuous spontaneous Ca2+-independent liberation of acetylcholine (ACh) from Torpedo electric organ synaptosomes. Differentiation between the release of ACh and choline was achieved by inhibiting cholinesterases with phospholine, and a way to quantify the continuous release was devised. The method permitted measurements during short time intervals from minute amounts of tissue and without an accumulation of ACh in the medium. Synaptosomes continuously liberated small amounts of ACh during incubations in the presence of 3 mM K+ and in the absence of Ca2+. The spontaneous liberation of ACh was similar both quantitatively and qualitatively at pH values of 8.6 and 7.8. It was unaltered by MgCl2 (10.4 mM), 2-(4-phenylpiperidino)cyclohexanol (10 microM), ouabain (104 microM), atropine (10 microM), and valinomycin (102 nM). Carbamoylcholine brought about a decrease, which could be partially reversed by atropine. The Ca2+-independent output of ACh was increased considerably when the concentration of K+ ions was raised (eightfold at 103 and 35-fold at 203 mM K+). Carbamoylcholine (104 microM) blocked the increase in ACh release produced by high K+; this effect of carbamoylcholine was not reversed by atropine (10 microM). When Ca2+ was added to synaptosomes depolarized by a high concentration of K+, the amount of ACh released during the first 1-3 min after the addition of Ca2+ was at least 20 times higher than in the absence of Ca2+, but the release returned rapidly to predepolarization values. Similarly high values of ACh release could be achieved by adding Ca2+ plus the ionophore A23187 and even higher values by adding Ca2+ plus gramicidin.(ABSTRACT TRUNCATED AT 250 WORDS)