The fine structure of the visual system of lycosa (Araneae: Lycosidae)

Summary The optic lobes of spiders contain a well differentiated synaptic region — the lame medullaire — in which the photoreceptor axon terminals synapse with the axons of the second order neurons.Each photoreceptor terminal has a very irregular outline and contains a great number of vesicles. It sends out collateral branches which end either in contact with other photoreceptor terminals or in contact with second order fibers. The second order fibers lie deeply recessed within folds of the photoreceptor terminal membrane. Frequently branches of the second order fibers can be seen as independent elements within the photoreceptor terminals. The synaptic loci are characterized by the presence of synaptic ribbons surrounded by cumuli of vesicles. These synaptic loci are always located at the intermembrane cleft between adjacent second order fibers.Synaptic structures have been found also within the second order fibers which in such cases appear as pre-synaptic elements in regard to the photoreceptor terminals.Research sponsored by the Air Force Office of Scientific Research, Office of Aerospace Research, United States Air Force, under AFOSR Grant Nr. 618-64.     

Subcellular localization of the major pneumococcal autolysin: a peculiar mechanism of secretion in Escherichia coli

The major pneumococcal autolysin (N-acetylmuramoyl-L-alanine amidase) has been localized in the cellular envelope of Streptococcus pneumoniae and Escherichia coli by using immunocytochemical labeling on ultrathin sections and whole-mounted cells. Cell fractionation experiments in E. coli confirmed the peripheral localization of the pneumococcal amidase and suggested that this enzyme is weakly bound to the outer face of the cytoplasmic membrane. This interaction does not depend on the presence of choline but represents an intrinsic property of the amidase. The autolysin, that is synthesized without any N-terminal signal sequence (García, P., García, J. L., García, E., and López, R. (1986) Gene (Amst.) 43, 265-272) was not processed during translocation. A new regulatory mechanism that might be specific for bacterial autolysins is discussed.     

Certain aspects of so-called post cholecystectomy syndrome

The study involved 126 patients with cholelithiasis. Set of biochemical, radiological, endoscopic, and ultrasound examinations was carried out in these patients. Potential coincidence of clinical symptoms and causes of so-called postcholecystectomy syndrome was the purpose of a 1-year follow-up studies. The significance of the results are discussed.     

Monotherapy with acebutolol in hypertensive diabetic patients

Monotherapy of hypertension with acebutolol in diabetics in daily dose of 200-400 mg for 6 weeks induced only non-significant and practically not acceptable hypotensive effect in groups of patients with hypertension and diabetes type I or type II without nephropathy. No therapeutical effect was observed in hypertension in diabetics type I with nephropathy. Administration of acebutolol to hypertensive diabetic patients with nephropathy resulted in tendency to increase in albuminuria. Values of creatinine clearance did not change at the same time. Also no effect of acebutolol on glycemic or lipid indices was observed. The lack of clear hypotensive effect under studied conditions of acebutolol in diabetic patients contrasted with its significant action in comparative group of hypertensive non-diabetic subjects.     

The role of insulin in the control of triacyglycerol (TG) in the rat skeletal muscles

The role of insulin in the control of triacyglycerol (TG) in different types of skeletal muscle has not been fully recognized so the aim of the present study was to fill this gap. The experiments were carried out on control rats, those fed with olive oil or fed with the oil and treated with insulin and on streptozotocin diabetic animals at rest and there after exercise till exhaustion. The level of TG was measured in the white and red layers of the vastus lateralis, the soleus and the diaphragm. It was found that acute feeding with olive oil had no effect on TG level in either muscle type examined. Insulin administered to rats fed with oil increased TG level in the red vastus. Streptozotocin diabetes caused an increase in TG level in muscles with high oxidative potential. Exercise lowered the level of TG only in the red vastus of the diabetic rats. It is concluded that insulin may increase muscle TG level. Accumulation of TG in muscles of rats with acute diabetes is likely to be a result of the high plasma free fatty acid concentration. Acute insulin deficiency did not affect the muscle TG response to exercise.     

Replication banding in the chromosomes of the European eel (Anguilla anguilla)

The chromosomes of the European eel Anguilla anguilla have been analyzed with a replication banding technique from lymphocyte cultures treated with 5-BrdU. This technique allows us to identify with high resolution the individual chromosome pairs and to differentiate classes of chromatin by the order of replication. The replication banding obtained on the chromosomes of European eel can be related with the structural bands described in this species.     

Humoral anti-idiotypic and anti-anti-idiotypic immune response in cancer patients treated with monoclonal antibody 17-1A

 A group of 96 patients with advanced colorectal carcinoma were treated with the mouse (m) or chimeric (c) (mouse variable regions × human IgG1 constant regions) monoclonal antibody (mAb) 17-1A recognizing the tumour-associated antigen GA733-2. Eighty-two of the 83 patients treated with mmAb17-1A and 69% of the patients given cmAb17-1A (n = 13) developed anti-idiotypic antibodies (ab₂). Auto-antibodies binding to tumour cells expressing GA733-2 were found in 7% of the patients. In a further 38 patients (40%) antitumour-cell antibodies, i.e. anti-anti-idiotypic antibodies (ab₃), were induced by the mAb17-1A therapy. Patients with detectable ab₃ after treatment had significantly higher ab₂ levels than those not developing ab₃. Addition of granulocyte/macrophage-colony-stimulating factor (GM-CSF) to mmAb17-1A significantly enhanced the induction of ab₂ as well as induction of anti-anti-idiotypic antibodies (ab₃), compared to mmAb17-1A alone. Patients with a high increase in antitumour-cell antibodies (ab₃) induced by the therapy lived significantly longer than patients with no or a low level of induction of ab₃ (P = 0.016). The results indicate that induction of an idiotypic network response might be an important effector mechanism in mAb therapy. Received: 20 October 1995 / Accepted: 18 December 1995     

Evaluation of the use of phase-specific gene promoters for the expression of enological enzymes in an industrial wine yeast strain

Summary Genes as POT1, HSP104 and SSA3, which are late expressed in laboratory culture conditions are expressed only during the first few days in microvinifications in wine yeast cells. This effect is probably due to the different growth conditions and leads to useless levels of enzyme activity for a reporter gene. However the ACT1 promoter, which is constitutively expressed in laboratory conditions, produces sufficient amounts of enzyme activity in late fermentation phases.     

Lectins as markers of rumen epithelial cell differentiation

Summary Lectins of different carbohydrate specificities (GNA (Galanthus nivalis), con A (Canavalia ensiformis), VFL (Vicia faba), PSL (Pisum sativum), LCA (Lens culinaris), PNA (Arachis hypogaea; with or without prior neuraminidase treatment), WGA (Triticum vulgare), SBA (Glycine max), UEA-I (Ulex europaeus), LPA (Limulus polyphemus), BS-I B₄ (Bandeiraea simplicifolia, isolectin B₄)) were explored for use as differentiation markers of rumen epithelial cellsin vivo andin vitro. Lectins specific for mannose (GNA), mannose/glucose (con A, VFL, PSL and LCA),N-acetylglucosamine (WGA) or forN-acetylneuraminic acid (LPA) reacted generally with all types of rumen epithelial cell from both rumen tissue and cell culture. They were, therefore, not suitable markers of epithelial differentiation. SBA was unsuitable because, although it reacted with both tissue and cultured rumen epithelial cells, it was also bound to non-stratified areas of primary rumen epithelial cell cultures. Both BS-I B₄ and PNA (after neuraminidase treatment) had to be ruled out because they did not react with differentiated rumen tissue epithelial cells, although they did bind to both stratified and non-stratified cultured cells. In contrast, UEA-I reacted strongly with differentiated rumen epithelial cells both from rumen tissue and cell cultures and therefore appears to be a good general marker for rumen epithelial cell differentiation.