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J Rossi

Publications and source records attributed to J Rossi.

At least 19 recordsLinked to original sources
PubMed1992

Analysis of the relationships between self-stimulation sniffing and brain-stimulation sniffing.

Determination of current thresholds for self-stimulation and electrically elicited sniffing from electrodes placed into lateral hypothalamic and ventral tegmental areas of rats revealed a tight correlative relationship between the two phenomena (r values of approx 0.9 at both sites). Thresholds for sniffing were never higher than those for self-stimulation, while approximately half the animals had higher self-stimulation than sniffing thresholds, suggesting that electrically elicited sniffing may better index the underlying psychobiological process that mediates self-stimulation. That both phenomena reflect the same basic process was suggested by the fact that 48 h of food deprivation consistently reduced the thresholds for both self-stimulation and sniffing, while 24 h of food deprivation had only marginal effects on both. The implications for understanding the nature of self-stimulation processes is discussed.

Animals↗
PubMed1992

Peptidase profiles of Pseudomonas fluorescens: identification and properties.

The cell-associated peptidase profiles of 12 strains of Pseudomonas fluorescens (ATCC 948 and 11 related biotypes) were examined. Employing Analytab system API ZYM, a general, strong peptidase activity was detected using L-lysyl-, L-pyrrolidonyl-, L-arginyl-, L-alanyl-, and glycyl-glycyl-beta-naphthylamides as substrates. Conversely, L-tyrosyl-, L-phenylalanyl-, L-histidyl-, L-prolyl-, gamma-L-glutamyl-beta-naphthylamides substrates were hydrolyzed by only a few strains. The peptidases were active, therefore, on substrates responsible for the bitter taste in dairy products. Properties of hydrolytic systems showed no significant changes in the enzymatic profiles when cells were grown on different fermentation media. Enzyme activity was relatively stable during refrigerated (5 degrees C) and frozen (-18 degrees C) storage. The peptidases of P. fluorescens ATCC 948, considered as reference, and strain 22 were identified on Pro-beta-naphthylamides by Michaelis constant values of .528 and .394 mM, respectively, and by different optimal pH and temperature activity on Leu- and Pro-beta-naphthylamides. The peptidase activity on Gly-Phe-beta-naphthylamide in P. fluorescens 30 had optimal values at pH 7.50 and 45 degrees C. These results confirm the relations defined in the enzymatic identification phase and suggest the presence of any analogous peptidases in the biovars of P. fluorescens considered.

Culture Media↗
PubMed1992

[Post-traumatic gas in children. Apropos of a case].

The authors report a case of post-traumatic gas in the portal vein in a child. They stress the rarity of this lesion in such circumstances and recall the radiological signs together with the differential diagnoses and the principal aetiologies.

Accidents, Traffic↗
PubMed1991

Effect of fixation on the amplification of nucleic acids from paraffin-embedded material by the polymerase chain reaction.

Amplification of nucleic acids from paraffin-embedded material by the polymerase chain reaction (PCR) is increasingly being used to detect viral genomes and oncogene mutations. To determine the effect of fixation on the preservation of the nucleic acids, we fixed two randomly chosen fresh pathology specimens in formalin, B-5, Bouin's, Zenker's, ethanol, and Omnifix for 6, 24, 48, 72, and 168 hr (1 week), and then embedded the tissue in paraffin. Oligonucleotide primers specific for the cytoplasmic-beta-actin gene were chosen to span an intron such that amplification yielded a product of 250 BP for DNA and 154 BP for RNA. A single 6-microns section was cut from each paraffin block, deparaffinized, and then subjected to 30 rounds of amplification for either DNA or RNA. On amplifying DNA, consistent product was seen in the ethanol and Omnifix specimens up to 72 hr of fixation time, whereas variable product was seen with formalin or Zenker's fixation; all specimens fixed in Bouin's or B-5 were negative. On amplifying RNA, a product could be detected even after 1 week of fixation in ethanol or Omnifix, and after 48 hr in the formalin-fixed tissue. The Zenker's-fixed tissues gave variable results, and the Bouin's and B-5 tissues gave consistent results only after 6 hr of fixation. We therefore conclude that choice of fixative and fixation time are critical factors influencing the outcome of PCR amplification of nucleic acids from paraffin-embedded material.

Base Sequence↗
PubMed1990

Monocytoid B-cell lymphoma in a patient with human immunodeficiency virus infection. Demonstration of human immunodeficiency virus sequences in paraffin-embedded lymph node sections by polymerase chain reaction amplification.

There is a significantly increased incidence of malignant lymphoma in patients with acquired immunodeficiency syndrome (AIDS). The lymphomas are usually of a high grade and of B-cell phenotype. While the frequent presence of reactive monocytoid B lymphocytes in patients with AIDS-related lymphadenopathy has recently been documented in several studies, to our knowledge, there are no reported cases of monocytoid B-cell lymphoma, the neoplastic counterpart of monocytoid B lymphocytes, in patients with AIDS. We now describe a human immunodeficiency virus (HIV)-positive patient with HIV-related lymphadenopathy in whom monocytoid B-cell lymphoma developed during the course of his disease. The morphologic and immunologic features of the lymphoma were characteristic of monocytoid B-cell lymphoma, and the involved lymph node exhibited a reversed CD4/CD8 ratio. Moreover, using the polymerase chain reaction, we were able to demonstrate HIV genome in DNA extracted from the lymph node tissue. To our knowledge, this is the first report of a case of monocytoid B-cell lymphoma occurring in an HIV-positive patient and in which we were able, by using a sensitive molecular biologic technique, to demonstrate HIV sequence in paraffin-embedded, fixed lymph node sections.

Acquired Immunodeficiency Syndrome↗
PubMed1986

An ancient developmental induction: heat-shock proteins induced in sporulation and oogenesis.

Every eukaryotic and prokaryotic organism tested to date synthesizes a small number of heat-shock proteins in response to heat and other forms of stress. A particular pattern of heat-shock gene expression was observed during ascospore development in Saccharomyces: heat-shock proteins hsp26 and hsp84 were strongly induced nor inducible by heat shock. Instead, two proteins related to hsp70 were induced. A strikingly similar pattern of expression occurs during oogenesis in Drosophila, suggesting that it may be one of the earliest developmental pathways to evolve in eukaryotic cells.

Drosophila↗
PubMed1986

Mutations in conserved intron sequences affect multiple steps in the yeast splicing pathway, particularly assembly of the spliceosome.

Yeast introns contain three highly conserved sequences which are known to be required for splicing of pre-mRNA. Using in vitro mutagenesis, we have synthesized seven point mutations at five different sites in these signals in the yeast actin intron. The mutant introns were then inserted into each of three constructs, which allowed us to assess the consequences both in vivo and in vitro. In virtually every case, we found the efficiency of splicing to be significantly depressed; mature mRNA levels in vivo ranged from 0 to 47% of wild-type. Surprisingly, the tightest mutations were not necessarily at the sites of nucleolytic cleavage and branch formation; these nucleotides are thus highly preferred, but are not absolutely necessary. Moreover, while particular nucleotides are specifically required for the final step in splicing, i.e. 3' cleavage and exon ligation, the predominant consequence of mutation within the conserved signals appears to be the inhibition of assembly of the splicing complex.

Actins↗
PubMed1986

Alpha-amylase and glucoamylase production by Schwanniomyces castellii.

A chromogenic substrate (Cibachron blue-amylose), and soluble starch and maltose were used to characterize the amylolytic system from Schwanniomyces castellii 3754. The strain was able to produce inducible alpha-amylase (EC 3.2.1.1) and glucoamylase (EC 3.2.1.3) when grown on different C sources. The effect of the C source was slightly different for alpha-amylase and glucoamylase production. Melezitose, maltose and soluble starch enhanced both alpha-amylase and glucoamylase synthesis to nearly the same extent; amylose, trehalose and cellobiose particularly induced alpha-amylase synthesis. The optimal pH for the release of both amylases was 5.5-7.0; maximal alpha-amylase synthesis, on the other hand, was observed in the medium buffered at pH 6.0. The optimal pH for alpha-amylase and glucoamylase activity was in the range of 4.5-7.2 and 4.2-5.5, respectively. Temperatures allowing maximal activity were 45 degrees C for alpha-amylase and 45-52 degrees C for glucoamylase; a rapid decline of both activities was observed just above these temperatures.

Glucan 1,4-alpha-Glucosidase↗
PubMed1986

Activation of a cryptic TACTAAC box in the Saccharomyces cerevisiae actin intron.

We constructed a translational fusion between the Saccharomyces cerevisiae actin gene and the Escherichia coli beta-galactosidase structural gene such that expression of beta-galactosidase activity required accurate splicing of the actin intron. Using this chimeric gene, we generated a series of internal deletions which removed the TACTAAC box or, in addition, TACTAAC-like sequences within the intron. Analysis of the fusion transcripts produced in these deletions allowed us to conclude that the TACTAAC-like sequence TACTAAG can substitute, albeit inefficiently, for the authentic TACTAAC box in the splicing process. These results indicate that the yeast splicing machinery can utilize a cryptic TACTAAC box, but there are requirements for primary sequence and proper position.

Actins↗
PubMed1985

Peptide- and non-peptide-containing unmyelinated primary afferents: the parallel processing of nociceptive information.

Primary afferent C fibres can be subdivided into a number of subgroups on the basis of cytochemistry or receptor binding characteristics. Numerous peptides have been localized to dorsal root ganglia, yet these appear to be only found in approximately 50% of small perikarya. A large proportion of the remaining small cells do not contain peptides but are identifiable in rodents by their content of a fluoride resistant acid phosphatase. Attempts have been made to correlate particular biochemical types with particular receptive field profiles, with rather modest success. As an alternative we suggest, principally from an analysis of skin afferents, that peptide- and non-peptide-containing afferents are two distinct C fibre pathways innervating similar peripheral structures and conveying similar information, but to different areas within the dorsal horn. Morphological evidence also suggests that these two subsystems form either glomerular or simple synaptic arrangements in the dorsal horn. The significance of parallel pathways for the processing of nociceptive information is briefly discussed.

Acid Phosphatase↗
PubMed1985

Radiation doses due to long-range transport of airborne radionuclides released by a reactor accident--effects of changing dispersion conditions during transport.

This paper presents a model for the estimation of radiation doses due to long-range transport of airborne radioactive material released into the atmosphere by a reactor accident. The paper includes examples of calculated doses in situations where the weather changes during the transport path. These examples show that changing dispersion conditions, such as rain, may bring about considerable changes in the individual doses. Short-term changes in turbulence, mixing depth and wind speed during the transport path also have a strong influence on doses.

Accidents↗
PubMed1979

Elevated plasma prolactin concentration in cholestasis of pregnancy.

The plasma concentrations of prolactin and estradiol-17 beta were measured by specific radioimmunoassays in 150 women with normal pregnancies and 76 women with cholestasis of pregnancy. At 33 to 34 weeks of gestation plasma prolactin concentrations were 187 +/- 23 ng/ml (mean +/- S.E.M.) for normal pregnancy and 341 +/- 38 ng/ml for cholestasis (p less than 0.001). At 35 to 36 weeks they were 254 +/- 24 and 355 +/- 26 ng/ml (p less than 0.01), and at 37 to 38 weeks 175 +/- 14 and 365 +/- 34 ng/ml (p less than 0.001), respectively. Higher prolactin levels in the cholestasis group were not related to differences in plasma estradiol-17 beta concentrations. No correlation was found between plasma prolactin and serum aminotransferase levels, or between prolactin levels and placental weight. The mechanisms by which plasma prolactin levels become elevated in cholestasis of pregnancy remain to be elucidated.

Cholestasis↗
PubMedDate not supplied

Detoxification of aflatoxin-polluted peanut cakes with monomethylamine/Ca(OH)2: pilot industrial application, nutrition experiments, toxicity evaluation.

The process described has been studied up to an industrial pilot scale. In this article this article we summarize the basic knowledge on the process and the technological conditions of pilot application for detoxifying peanut cakes polluted by up to 3,500 ppb Aflatoxine (2,300 ppb B1). The nutritional experiments carried out on rats and other mammals are described, and the toxicological and biochemical evaluation of the cakes on Bacillacea are reported and discussed. The data collected show that the MMA/Ca(OH)2 process offers promising possibilities for industrial application on the basis of technological and economic criteria, as well as from the point of view of efficiency and safety.

Aflatoxins↗