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Biomedical subjects

M Russo

Publications and source records attributed to M Russo.

At least 145 records · Page 8Linked to original sources
PubMed1993

Resistance of genetically selected mice to MHV3 infection is not dependent on the H2O2 release by macrophages.

The genetically selected high antibody responder line of mice (HIII) for a natural immunogen were fully susceptible to mouse hepatitis virus 3 (MHV3) and the corresponding low antibody responder mice (LIII) were fully resistant, regardless of whether they were previously treated or not with the bacillus Calmette-Guérin (BCG). The resistance or susceptibility correlated with the virus growth in the peritoneum of mice. Peritoneal cells isolated from resistant mice released higher amounts of H2O2 after phorbol myristate acetate (PMA) stimulation than susceptible mice. No spontaneous in vitro H2O2 release by peritoneal exudate cells from HIII mice, shown to be mostly macrophages, were observed during the MHV3 infection. In contrast, the spontaneous in vitro H2O2 release by these cells from MHV3-infected LIII mice increased gradually, reaching a maximal value 3 days after infection, and decreased in parallel to the virus clearance from the peritoneum. The BCG treatment primed the macrophages of HIII mice for the production of H2O2 during the MHV3 infection, but did not confer resistance against the virus infection. The data obtained suggest that the acquired capability of macrophages to release H2O2 does not participate in the anti-MHV3 activity or resistance against the MHV3 infection.

Animals↗
PubMed1993

Repair in vivo of altered 3' terminus of cymbidium ringspot tombusvirus RNA.

Progeny RNA of CyRSV RNA transcripts ending with -GGG, instead of -CCC as in wild-type RNA, was analyzed and shown to revert to wild-type. A new full-length cDNA clone of CyRSV was prepared, bearing the correct 3' terminus, from which transcripts could be synthesized having very high infectivity. Mutants were prepared which lacked the three terminal Cs; transcripts were infectious and most cDNA clones recovered from progeny RNA had regained the wild-type sequence. Transcripts ending in -GGCCAn were also infectious, and the 3' sequence of most cDNA clones recovered after inoculation was the same as the inoculum sequence. Deletion of G at position -4 completely abolished infectivity. The occurrence of a repair mechanism at the 3' end of CyRSV similar to telomerase activity on chromosomes is suggested.

Base Sequence↗
PubMed1993

Functional analysis of cymbidium ringspot virus genome.

Genomic RNA of cymbidium ringspot tombusvirus (CyRSV) contains five large open reading frames (ORFs). The two 5' proximal ORFs encode proteins of 33 and 92 kDa and the three 3' proximal ORFs encode proteins of 41, 22, and 19 kDa. In addition, a small reading frame encoding a protein of 4 kDa was recently observed by computer analysis of the 3' nontranslated region of CyRSV and other tombusvirus RNAs (ORF 6). The function of putative gene products was investigated with the use of several mutants. Mutants in ORFs 1 and 2 were not viable indicating that both 33- and 92-kDa proteins are required for replication. Deletion of a large portion of the coat protein gene, encoding a 41-kDa protein, did not prevent replication of viral RNA and cell-to-cell movement, but interfered severely with long-distance translocation. No virus particles or viral RNA could be detected in inoculated or upper leaves of plants inoculated with transcripts obtained from mutants not expressing the 22-kDa protein. However, replication and encapsidation occurred normally in inoculated protoplasts indicating that this gene product is a transport protein. Conversely, no role could be assigned to putative gene products of ORF5 (19-kDa protein) and ORF6. It was also shown that factors other than gene expression can influence the replication of RNA mutants, probably due to instability of RNA molecules.

Base Sequence↗
PubMed1993

Resistance to cymbidium ringspot tombusvirus infection in transgenic Nicotiana benthamiana plants expressing the virus coat protein gene.

Transgenic Nicotiana benthamiana plants expressing the coat protein gene of cymbidium ringspot virus (CyRSV) were tested for resistance against infection with CyRSV. Transgenic plants showed resistance to infection only when the purified virions concentration in the inoculum was as low as 0.05 micrograms/ml. No protection was observed in transgenic plants inoculated with virion concentrations of 0.5 and 5.0 micrograms/ml or when the inoculum was in vitro synthesized genomic RNA.

Base Sequence↗
PubMed1993

Diet and exercise strategies of a world-class bodybuilder.

This study presents the diet and exercise strategies of a world-class body-builder during an 8-week precompetition period. Weighed food records were kept daily, and body fat, resting metabolic rate (RMR), VO2max, blood lipids, and liver enzymes were measured. Two hrs of aerobic exercise and 3 hrs of weight training were done daily 6 days/week. Mean energy intake was 4,952 kcal/day (54 kcal/kg) and included 1,278 kcal/day from medium-chain triglycerides (MCT). Diet without MCT provided 76% of energy from carbohydrate, 19% from protein (1.9 g protein/kg), and 5% from fat. Micro-nutrients were consumed at > or = 100% of the RDA, except for zinc and calcium, without supplementation. Mean RMR was 2,098 kcal/day and represented 43% of energy intake. VO2max was 53 ml.kg-1.min-1. Underwater weighing showed that body fat decreased from 9% to 7%. Blood lipids were normal, but two liver enzymes were elevated (alanine and aspartate aminotransferase). This world-class bodybuilder achieved body fat goals by following a nutrient dense, high energy, high carbohydrate diet and an exercise program that emphasized both aerobic and anaerobic metabolism.

Adipose Tissue↗
PubMed1993

Differential sensitivity of mouse strains to platelet activating factor-induced vasopermeability and mortality: effect of antagonists.

In the present study, we have compared the responses to platelet-activating factor (PAF) of A/J and BALB/c inbred mouse strains. Two PAF-induced events were analyzed: increased vasopermeability, measured by extravasation of Evans blue dye (EB), and mortality. PAF injected into the peritoneal cavity induced a bell-shaped dose-response curve of EB extravasation in both strains of mouse. In A/J mice, maximal EB extravasation was reached with 0.1 microgram of PAF/mouse, whereas in BALB/c mice maximal extravasation was attained at a 10-fold greater PAF concentration. PAF-induced mortality also differed among these mouse strains; the LD50 was 12.1 micrograms/kg in A/J and 21.2 micrograms/kg in BALB/c mice. Thus, these strains differ significantly regarding both events mediated by PAF. Surprisingly, the F1 hybrid (A/J x BALB/c) mice were as sensitive as the A/J strain to PAF-induced extravasation but were as resistant as the BALB/c mice to PAF-induced mortality. The effects of the PAF antagonists BN 52021 and WEB 2086 were compared in the F1 hybrids. It was found that 1.0 mg/kg of WEB 2086 affected PAF-induced extravasation at almost all PAF doses tested (0.03-3.0 micrograms) while 15 mg/kg of BN 52021 was only effective at doses of PAF below 0.3 microgram. Both antagonists prevented PAF-induced mortality. Our results indicate that the two events induced by PAF may be controlled by different genes.

Animals↗
PubMed1993

Advances in experimental paracoccidioidomycosis using an isogenic murine model.

A genetically controlled murine model of paracoccidioidomycosis which allowed us to investigate several parameters of the host-parasite interactions was established in our laboratory. Natural resistance and acquired immune responses to P. brasiliensis infection were investigated employing resistant and susceptible mice infected with highly virulent or slightly virulent P. brasiliensis isolates. Resistant mice inoculated with a highly virulent P. brasiliensis isolate present efficient macrophage activation, presence of DTH response, low levels of specific antibody and a tendency to resolution of the infectious process, suggesting that a T helper-1 mode of immune response is mounted. Susceptible mice, on the contrary, seem to mount a predominantly T helper-2 type of immune response activation in which an inefficient macrophage activation, depressed DTH reactions and high levels of antibodies result in progressive disease. The crucial role of the fungal virulence on the outcome of the infection of susceptible and resistant mice is also demonstrated, thus reinforcing the idea that both the innate resistance of the host and the pathogenicity of the fungal cells are determinant on the outcome of the disease. This model is proposed as a framework of our current knowledge of the host-parasite interactions in paracoccidioidomycosis and as a basis for future challenge in continuing analyses.

Animals↗
PubMed1993

Clinical and histological aspects of chronic HCV infection and cirrhosis.

We studied 608 consecutive cases of anti-HCV-positive chronic liver disease. In 358 patients the diagnosis was established by needle liver biopsy. In 250 patients with liver cirrhosis the diagnosis was made on the basis of the unequivocal clinical signs and the results of imaging procedures. Chronic HCV infection is usually observed in adults or elderly patients; the age of the patients steadily increases with the progression of the illness to the more severe stages. Jaundice was infrequent in patients with chronic hepatitis or early cirrhosis; clinical symptoms and laboratory tests are of little value in differentiating CPH from CAH or in detecting early cirrhosis. Serum aminotransferases were usually only slightly elevated in all stages of the disease. Despite the mildness of the hepatic cytolysis, the progressive reduction in serum cholinesterase and albumin concentrations and the progressive increase in the serum alkaline phosphatase activity indicate progressive failure in the hepatic function in the course of the illness. The histological study showed that steatosis, follicular portal inflammation and eosinophilic changes in the hepatocytes were prominent features of chronic HCV infection. In contrast, severe piecemeal necrosis without bridging was rarely observed.

Adult↗
PubMed1992

Typhoid fever in the Neapolitan area: a case-control study.

Typhoid fever is endemic in the Neapolitan area, where its yearly incidence rate largely exceeds the corresponding national figure. During the period from January to June, 1990, a matched case-control study was carried out in order to identify risk factors of the disease in this area; 51 subjects (mean age 27.2 years) with typhoid fever were compared with 102 controls matched with respect to age, sex and educational level. Consumption of raw shellfish was reported by 76.5% of the cases, as opposed to 19.6% of the controls (P < 0.01). Subjects who had eaten this food item had a 13.3-fold risk (C.I. 95% = 5.5 - 32.8) of contracting typhoid fever. In contrast, no risk was found to be associated with consumption of cooked shellfish, raw vegetables, ice-cream, non-potable water, or unpasteurized milk. The risk factor identified in this study shows that hazardous dietary habits and inadequate sewage treatment facilities, combined with lack of sanitation in the harvesting and marketing of shellfish, play a major role in the endemicity of typhoid fever in the Neapolitan area.

Case-Control Studies↗
PubMed1992

Unusual onset of severe varicella in adult immunocompromised patients.

Abdominal and back pain has until now been reported as a first sign of severe varicella in immunocompromised children only. We report two adult leukemia patients in whom these symptoms preceded visceral dissemination of varicella infection. Recognizing that this syndrome may occur in adult patients is of clinical importance, since it allows early diagnosis and treatment of the infection.

Abdominal Pain↗
PubMed1992

Biologically active cymbidium ringspot virus satellite RNA in transgenic plants suppresses accumulation of DI RNA.

A full-length DNA copy of cymbidium ringspot virus (CyRSV) satellite RNA was cloned downstream of the bacteriophage T7 RNA polymerase promoter. In vitro transcripts were biologically active in plants when coinoculated with the helper virus or its RNA. Although the transcripts contained 7 or 29 extra nucleotides at the 3' end, the proper 3' terminus was restored in the satRNA progeny. Full-length cDNA clones of CyRSV satRNA under the control of the cauliflower mosaic virus 35S promoter and terminator were used to transform Nicotiana benthamiana plants. Integration of CyRSV satRNA sequence in the plant genome was tested by PCR amplification of DNA extracts from transformed plants and by detection of satRNA-related transcripts in total RNA extracts. Inoculation of transgenic plants with the helper virus induced replication of satRNA of the same size as the native molecule. Sequence analysis of the satRNA progeny showed that it was identical to natural CyRSV satRNA. Infected transgenic plants were not protected from apical necrosis and death by the presence of satRNA sequences. Rather, replication of satRNA was found to suppress accumulation of defective interfering RNA, which acts in the absence of satRNA as an attenuator of virus replication and disease.

Base Sequence↗
PubMed1992

The replication of cymbidium ringspot tombusvirus defective interfering-satellite RNA hybrid molecules.

A DNA copy of DI RNA of cymbidium ringspot tombusvirus was cloned downstream of a phage T7 promoter. In vitro-transcribed RNA replicated in Nicotiana clevelandii when co-inoculated with full-length viral genomic RNA transcripts and protected plants from apical necrosis. Artificial deletion mutants derived from the DI RNA clone showed that most of the central sequence block is necessary for replication. Hybrid DI RNA-satRNA clones were prepared and in vitro-synthesized RNA was inoculated to plants in the presence of helper viral RNA. There was replication only of in vitro transcripts derived from hybrid clones where satRNA sequences were inserted upstream or downstream from the central block, but not of those derived from clones where satRNA sequence replaced the central block. Progeny RNA of biologically active clones was either full-length or showed deletions depending on the insertion of satRNA sequences in DI RNA. DI RNA-satRNA constructs having part of the 5' region exchanged were not replicated.

Base Sequence↗
PubMed1992

A liquid chromatographic assay using a high-speed column for the determination of lamotrigine, a new antiepileptic drug, in human plasma.

A sensitive, specific and rapid liquid-chromatographic method for the determination of the new antiepileptic drug lamotrigine (LTG) in human plasma is described. The method involves the use of a commercially available 3-microns particle size normal-phase column and a microflow-cell-equipped ultraviolet detector. Extraction is carried out with ethyl acetate after alkalinization on a 100-microliters plasma sample containing LTG and 3,5-diamino-6-(2-methoxyphenyl)-1,2,4-triazine as internal standard. The residue is reconstituted with 50 microliters of ethanol, and 5 microliters of the final solution is injected into the column. Elution is carried out at 35 degrees C using n-hexane/absolute ethanol/35% ammonia (80/20/0.25 by volume) as mobile phase at a flow rate of 2.0 ml/min. Detection is at 313 nm. The chromatographic separation requires < 3 min and the sensitivity limit is < 0.1 mg/L. Recovery is 88-96.2%, whereas within-day and day-to-day coefficients of variation are between 4.1 and 7.7%.

Anticonvulsants↗
PubMed1992

Elevation of plasma phenytoin by viloxazine in epileptic patients: a clinically significant drug interaction.

The effect of viloxazine (150-300 mg daily for 21 days) on plasma phenytoin levels at steady state was examined in 10 epileptic patients stabilised on a fixed phenytoin dosage. After starting viloxazine treatment, plasma phenytoin concentrations increased by 37% on average (range 7-94%) from a mean value of 18.8 micrograms/ml at baseline to a mean value of 25.7 micrograms/ml during the last week of combined therapy. In four patients the rise in plasma phenytoin was associated with the development of signs of phenytoin toxicity. Discontinuation of viloxazine resulted in return of plasma phenytoin towards baseline values and disappearance of the clinical symptoms. The mechanism of interaction probably involves inhibition of phenytoin metabolism by viloxazine. Careful monitoring of plasma phenytoin levels is recommended in patients treated with phenytoin who need to be started on viloxazine therapy.

Adult↗
PubMed1992

[Vaccination against hepatitis A].

Hepatitis A is a worldwide disease transmitted by oral-fecal route, the endemicity level is high in developing countries and in the Far East. In northern Europe the endemicity level is low, but it is intermediate in the European Mediterranean area. Seroepidemiological surveys show that in Italy, as in many other European countries, hepatitis type A endemicity is declining. Therefore, immunity to infection shifts towards the older generations, leaving an increasing number of teenagers and young adults susceptible to the infection. Since in adults the infection is associated with higher levels of morbidity and mortality than in children, hepatitis A remains a public health problem. Moreover, travellers visiting an endemic area are at risk of acquiring the disease. Short-term, passive immunization with immune serum globulins is not a satisfactory method of controlling hepatitis A. The best way of controlling HAV endemicity is vaccination and a satisfactory vaccine will be available by 1993. Soon after HAV propagation in cell culture was achieved, three different approaches to HAV vaccine production were investigated: recombinant vaccines, live attenuated vaccines, inactivated vaccines. The production of a recombinant vaccine is, as yet, unavailable, because two HAV surface proteins linked together in a definite three dimensional configuration are needed to stimulate an effective immune response. A satisfactory live attenuated vaccine has not yet been obtained because of difficulties in maintaining a stable level of attenuation. Consequently, attention has shifted towards inactivated vaccines, and the HM 175 strain inactivated vaccine has been produced and widely studied in over 25,000 human volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Differences in macrophage stimulation and leukocyte accumulation in response to intraperitoneal administration of glucose/mannose-binding plant lectins.

Peritoneal macrophage stimulation (rapid spreading on glass surface and hydrogen peroxide production) and inflammatory reaction (leukocyte accumulation) obtained in C3H/HeJ mice at 8 weeks of age, after a single ip injection of 10 micrograms concanavalin A (Con A), a lectin extracted from Canavalia ensiformis, were compared with those obtained with two other glucose/mannose-binding lectins extracted from Canavalia brasiliensis (Con Br) and Dioclea grandiflora (DGL). All lectins enhanced macrophage spreading 3- to 4-fold at 24-72 h compared to control. Stimulation of hydrogen peroxide release by Con A, Con Br and DGL lasted 1, 2 and 3 days, respectively. Leukocyte cell influx at 24-72 h after lectin injection consisted mainly of mononuclear cells. Con A induced a moderate increase in the total number of peritoneal cells, whereas administration of Con Br or DGL increased the number of peritoneal cells 2- to 3-fold. The results indicate that DGL and Con Br have more pronounced effects on macrophage stimulation and inflammatory reactions than Con A.

Animals↗