Coexpression of vimentin and desmin in gastric leiomyomas. An immunohistochemical study in paraffin sections

The aim of the study was to evaluate the incidence of the reactions for vimentin and desmin in gastric leiomyomas routinely processed in formalin and embedded i paraffin. The material studied included four benign leiomyomas, seven malignant leiomyomas and three malignant epithelioid leiomyomas. A positive reaction to vimentin was found in 13 out 14 leiomyomas under study. The number of neoplastic cells showing vimentin expression was larger in malignant, especially epithelioid leiomyomas than in non-malignant leiomyomas. A positive reaction for desmin in neoplastic cells was found in 9 leiomyomas 64%. One non-malignant leiomyoma showed a moderate reaction. In the remaining eight cases the reaction was weak and occurred in single neoplastic cells. Coexpression of vimentin and desmin in neoplastic cells occurred in 8 out of 9 leiomyomas with a positive reaction for desmin. Coexpression of vimentin and desmin occurred also in the smooth muscle cells of blood vessels in all 14 cases. A weak reaction for desmin or its lack in the tumour cells of leiomyomas with its marked expression in the smooth muscle cells of the blood vessels and gastric wall outside the tumor points rather to a small number of desmin filaments in the neoplastic cells than to their destruction by fixation in formalin. The occurrence of the reaction to desmin only in a limited number of neoplastic cells questions the reliability of its use in the oligopiopsy material.     

Ribosomal proteins S7 and L1 are located close to the decoding site of E. coli ribosome--affinity labeling studies with modified tRNAs carrying photoreactive probes attached adjacent to the 3''-end of the anticodon.

Two photoreactive azidonitrophenyl probes have been attached to Yeast methionine elongator tRNA by chemical modification of the N6-(threoninocarbonyl)adenosine located next to the 3'-end of the anticodon. The maximum distance between the purine ring and the azido group estimated for the two probes is 16-17 and 23-24A, respectively. Binding and cross-linking of the uncharged, modified tRNAs to E. coli ribosomes have been studied with and without poly(A,U,G) as a message, under conditions directing uncharged tRNAs preferentially to the P-site. The modified tRNAs retain their binding activity and upon irradiation bind covalently to the ribosome with very high yields. Protein S7 is the major cross-linking target for both modified tRNAs, in the presence or absence of poly(A,U,G). Protein L1 and to a lesser extent proteins L33 and L27 have been found to be cross-linked with the short probe. Cross-linking to 168 rRNA reaches significant levels only in the absence of the message.     

Expression of nonspecific cross-reacting antigen species in myeloid leukemic patients and healthy subjects

The reactivity of two monoclonal antibodies recognizing NCA-95 and NCA-55 (MAb 47 and MAb 192, respectively) with a polyclonal anti-NCA serum in myeloid leukemic cells isolated by density gradient centrifugation was compared using an immunofluorescence test (IF). It was observed that the blood myeloid cells in 78.8% of the patients with different types of myelocytic leukemias and all granulocytes of 15 normal donors showed similar expression of the NCA species studied. The leukocytes of the remaining patients did not synthesize the NCA-95 species regardless of the maturation stage of the cells studied. In two patients, synthesis of this NCA form was limited to the fractions containing myelocytes and metamyelocytes. We have found that all anti-NCA antibodies studied recognized different antigenic epitopes in a myeloid cell series. A relationship between the patient's survival and the proportion of NCA-containing cells was also observed.     

Formation and function of accessory nuclei in the oocytes of the bird louse,Eomenacanthus stramineus (Insecta,Mallophaga)

In the oocytes of Eomenacanthus stramineus accessory nuclei arise by budding from the nuclear envelope. It is suggested that microtubules and the thick layer of the nuclear lamina are involved in this process. Newly formed accessory nuclei contain aggregations of fibrillogranular material. These aggregations are slightly Feulgen positive, RNA negative and stain positively with the AgNOR method. During later developmental stages one dense, RNA-positive inclusion appears in each accessory nucleus. These inclusions consist of on Ag-NOR-positive cortical layer and an Ag-NOR-negative core. The function of accessory nuclei in the species investigated is discussed in the light of these results.     

Intergeneric relationships ofLolium,Festuca, andVulpia (Poaceae) and their phylogeny

Morphological and seed protein analyses of 26 species of the generaLolium, Festuca andVulpia confirmed their close systematic affinities. Six inflorescence characters readily differentiatedFestuca fromLolium. Protein similarities betweenFestuca of sect.Bovinae and cross-pollinated species ofLolium, coupled with cytogenetic and crossability data, substantiate that they should be united into one genus.Vulpia had phenetic similarities with sect.Scariosae, Montanae andOvinae ofFestuca. Lolium, Festuca, andVulpia are most likely derived from a common ancestral form which was close toFestuca pratensis andLolium perenne.     

Hyperiodothyroninaemia of neonates, its significance for thermogenesis

Danowski et al. (1951) were probably the first who showed an increase of PBI in infants shortly after birth. Later a number of investigators presented further evidence on the increased thyroid gland function in newborns. This condition named "neonatal thyroid hyperactivity" [Fisher and Oddie, 1964] was described also in animals. The available data indicate that all the newborn mammals till now studied, independently of the maturation stage of development they reach at birth, display some features of thyroid hyperactivity, but in some it does not lead to hyperiodothyroninaemia. Interspecies differences coincide well with significance of the thyroid hormones for neonatal thermogenesis. There are few sequential studies of the three principal iodothyronines: T4, T3 and rT3 available at present. The most comprehensive data concern infants, newborn lambs and pigs. Immediately after birth, there is a sudden rise in serum thyroid hormone concentrations, with some species differences related to the degree of the increase and to the iodothyronines involved. The course of the postnatal hyperiodothyroninaemia is dependent on the maturation level reached at birth, food intake, and cooling relative to extrauterine environment. At least five main factors contribute to the immediate postnatal hyperiodothyroninaemia: 1) abrupt depletion of the preformed fetal hormonal iodine stores; 2) preferential T3 secretion; 3) increase in the T4 to T3 monodeiodination in the peripheral tissues; 4) a release of thyroid hormone content from peripheral reservoirs to plasma, and 5) action of other hormone(s) concomitantly released at birth. From the point of view of the thermal adaptability, the newborn mammals fall into two distinct groups: first, in which immediately after birth the metabolic rate decreases, and second, in which the metabolic rate increases, after cooling. Our understanding of the role and significance of hormonal factors involved in mechanisms of the postnatal thermogenesis is incomplete. However, some similarities in adaptation to cold in adults and in newborns seem to be relevant. Cold adaptation is accomplished by development of nonshivering thermogenesis (NST) depending on NA. The presence of brown adipose tissue (BAT) is essential for NA thermogenic action. According to the common opinion, based on data from laboratory animals and human baby, non-shivering thermogenesis, but not shivering, predominates in newborns. However, data from domestic animals indicate that shivering thermogenesis may be of comparable or greater thermogenic capacity than NST at birth. Besides, there are some newborns which have little or no BAT and associated NST.(ABSTRACT TRUNCATED AT 400 WORDS)     

Homologous and heterologous β-adrenergic desensitization in hepatocytes. Additivity and effect of pertussis toxin

In hepatocytes obtained from hypothyroid rats, phorbol myristate acetate (PMA) and vasopressin diminished the accumulation of cyclic AMP and the stimulation of ureagenesis induced by isoprenaline or glucagon without altering significantly the accumulation of cyclic AMP induced by forskolin. Pretreatment with PMA markedly reduced the stimulation of ureagenesis and the accumulation of cyclic AMP induced by isoprenaline or glucagon. In membranes from cells pretreated with PMA, the stimulation of adenylate cyclase induced by isoprenaline + GTP, glucagon + GTP or by Gpp[NH]p were clearly diminished as compared to the control, whereas forskolin-stimulated activity was not affected. The data indicate heterologous desensitization of adenylate cyclase. It was also observed that the homologous (García-Sáinz J.A. and Michel, B. (1987) Biochem. J. 246, 331–336) and this heterologous β-adrenergic desensitizations were additive. Pertussis toxin treatment markedly reduced the heterologous desensitization of adenylate cyclase but not the homologous β-adrenergic desensitization. It is concluded that the homologous and heterologous desensitizations involve different mechanisms. The homologous desensitization seems to occur at the receptor level, whereas the heterologous probably involves the guanine nucleotide-binding regulatory protein, Ns.     

Reversing the inhibitory effect of paclobutrazol on seed germination of Amaranthus paniculatus by GA3, ethephon or ACC

The germination of Amaranthus paniculatus seeds was inhibited by applying paclobutrazol, a specific inhibitor of gibberellin biosynthesis. This inhibition was markedly counteracted by gibberellin A₃ (GA₃), suggesting that endogenous gibberellins are required for germination in this species. The inhibitory effect of paclobutrazol was also overcome by ethephon (2-chloroethylphosphonic acid) or the precursor of ethylene biosynthesis, ACC (1-aminocyclopropane-l-carboxylic acid). Thus the physiological effect of gibberellin can be mimicked by ethylene released from ethephon or synthesised from exogenous ACC. It is suggested, that endogenous gibberellins are involved in germination of Amaranthus paniculatus seeds and that action of GA₃ can be substituted by ethylene.Abbreviations ACC 1-aminocyclopropane-l-carboxylic acid - AMO-1618 (2-isopropyl-5methyl-4-trimethylammoniumchloride)-phenyl-l-piperidinium-carboxylate - ancymidol -cyclopropyl--(4-methoxyphenyl)-5-pyrimidine methanol - chloromequat chloride (2-chloroethyl)trimethylammoniumchloride - ethephon 2-chloroethylphosphonic acid - GA gibberellin A₃ - paclobutrazol (2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-lyl)pentan-3-ol - Phosphon D 2,4,dichlorobenzyl-tributhylphosphoniumchloride - tetcyclacis 5,(4-chlorophenyl)-3,4,5,9,10-pentaaza-tetracyclo)5,4,1,0,Z,6,0^8,11 dodeca-3,9-diene     

Deoxynivalenol and 3-acetyldeoxynivalenol and Fusarium species in winter triticale

Fusarium species infecting heads of Triticale and mycotoxins presence in infected kernels and chaff were studied during two seasons. The most important species observed on infected heads were in 1986F. avenaceum (39%),F. nivale (21%),F. culmorum (20%),F. graminearum (14%), and others (6%). In 1987 after long and snowy winterF. nivale dominated (64%), followed byF. avenaceum (24%),F. culmorum (6%), andF. graminearum (5%). The mycotoxins deoxynivalenol (DON) and 3-acetyl DON were present in all 11 subsamples of kernels from heads infected byF. culmorum and/orF. Graminearum (1.6–16.4 mg and 0.7–2.4mg/kg, respectively). Chaff from the same subsamples contained 9.9–33.2mg/kg of DON and 5.2–16.0mg/kg of 3-AcDON. Kernels with visibleFusarium-damage contained 2.4–31.2 mg/kg of DON and 1.2–6.0 mg/kg of 3-AcDON. Remaining part of kernels without symptoms of visibleFusarium-damage contained only DON in an amount of 0.9–5.9 mg/kg.