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M Russo

Publications and source records attributed to M Russo.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1991

Mutagenesis of the cyanobacterium Spirulina platensis by UV and nitrosoguanidine treatment.

The production of Spirulina platensis cells resistant to 8-azaguanine or beta-(2-thienyl)-DL-alanine following mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and UV-irradiation is described. The conditions for the mutagenesis were determined by monitoring cell viability and the appearance of the two types of mutants as a function of the stage of growth of the tricomes and the length and the conditions of the treatment. The optimal conditions for UV and MNNG mutagenesis were found to be 1-3 min irradiation and 30 min incubation with 50 micrograms MNNG/ml of tricomes derived from cultures entering stationary phase sonicated for 10 s and 5 s respectively. Under these conditions beta-(2-thienyl)-DL-alanine-resistant mutants appeared at a frequency greater than or equal to 10(-4) and greater than or equal to 10(-5) following UV- and MNNG-mutagenesis, respectively. Mutants resistant to 8-azaguanine were found at a frequency approx. 10(-5) only after MNNG mutagenesis. A few chlorate-resistant mutants were also obtained following UV treatment.

Cyanobacteria↗
PubMed1991

Activation signals leading to proliferation of normal and leukemic CD3+ large granular lymphocytes.

The activation signals leading to proliferation of normal and leukemic CD3+ large granular lymphocytes (LGL) were studied in vitro. Anti-CD3 monoclonal antibody (MoAb) alone (P less than .01) and recombinant interleukin-2 (IL-2) alone (P less than .01) caused significant stimulation of peripheral blood mononuclear cells (PBMC) from four CD3+ LGL leukemia patients, as measured in a 3H-thymidine incorporation assay. Recombinant interleukin-4 (IL-4) alone had no effect (P = .11). The combination signals of anti-CD3 MoAb and either IL-2 or IL-4 produced a proliferative response greater than anti-CD3 MoAb alone (P less than .01) or lymphokine alone (P less than .01). Leukemic LGL, purified by two-color sorting, were subsequently activated by anti-CD3 MoAb and IL-2 and assessed for DNA content by viable Hoechst No. 33342 (HO) staining. Results of these studies demonstrated that leukemic LGL were stimulated directly by anti-CD3 MoAb and IL-2, with the percentage of cells in cell cycle (S + G2/M) ranging from 16% to 72%. Normal CD3+ LGL were also stimulated to enter the cell cycle by anti-CD3 and IL-2. These results show that leukemic LGL proliferate in vitro after activation through the T-cell receptor and/or lymphokine.

Antibodies, Monoclonal↗
PubMed1991

Is TNF alpha involved in early susceptibility of Trypanosoma cruzi-infected C3H/He mice?

Early wasting and subsequent mortality may occur in mice of some inbred strains following infection with Trypanosoma cruzi. It was hypothesized that TNF alpha/cachectin might be involved in this process. Thus, sera collected from mice of strains differing in their susceptibility or resistance to Trypanosoma cruzi infection were checked for the presence and level of TNF alpha, a cytokine able to exert acute toxic effects. C3H/HeJ or C3H/HePas (susceptible), BALB/c (intermediate) and C57BL/6 (resistant) mice were infected with the CL or Colombian strain of Trypanosoma cruzi, and TNF activity was measured in the sera during the acute phase of the infection. Only serum collected from infected C3H/He mice contained TNF activity. However, TNF activity could be measured in serum of all strains, following LPS infection, indicating that the infection was able to prime macrophages of infected mice to secrete TNF alpha. The TNF alpha/cachectin release in the sera of C3H mice may play a role in the early wasting and death of these mice after Trypanosoma cruzi infection.

Acute Disease↗
PubMed1991

De novo generation of cymbidium ringspot virus defective interfering RNA.

Nicotiana clevelandii plants were inoculated with cymbidium ringspot tombusvirus RNA synthesized in vitro, after which further passages were made by sap inoculation. During the third passage, low Mr RNA species appeared which had the characteristics of deletion mutants of genomic RNA. Sequence analysis of several of these defective interfering RNAs suggested a possible evolution of smaller from larger molecules. Computer-generated secondary structures of sequences surrounding recombination sites were extensive and stable and these sites occurred in interior or hairpin loops, thus providing a possible explanation for discontinuous RNA transcription and the formation of deletions in genomic RNA.

Base Sequence↗
PubMed1990

[Prevention of congenital toxoplasmosis].

Toxoplasma gondii can be transmitted from mother to fetus during primary maternal infection acquired after or, possibly, slightly before conception. The incidence of congenital infection is highest in the third trimester, while severity is greatest when maternal infection is acquired during the first trimester. About 50 per cent of mothers who acquire the infection during gestation, if not treated, will give birth to infected infants. Incidence of congenital toxoplasmosis varies from 0.5 to 6.5 cases per 1000 live births. Serologic screening before or very early in pregnancy is required to identify seronegative women who are at risk to acquire the infection during pregnancy. Prevention of congenital toxoplasmosis is obtained by educating pregnant women at risk about how to prevent the infection and by diagnosing acute infection of mother. Every mother who demonstrates seroconversion for toxoplasmosis during pregnancy has to be treated as soon as possible. Therapy is based on spiramycin that achieves high concentrations in the placenta; if the fetus is infected pyrimethamine plus sulphonamides are administered since fourth month. Chemotherapy of the infected pregnant mother reduces the incidence of congenital toxoplasmosis and the severity of the disease in the newborn. Intrauterine infection can be detected by fetal blood sampling, by amniocentesis and ultrasound examination; prenatal diagnosis is mandatory if an abortion is being considered.

Adult↗
PubMed1990

Studies on inflammatory response induced by Ehrlich tumor in mice peritoneal cavity.

In the present study we investigated the inflammatory response induced by the inoculation of Ehrlich tumor cells (EAT) into the peritoneal cavity of mice. It was found that after inoculation of 10(3) EAT cells, the number of peritoneal leukocytes remained unchanged till the sixth day. Subsequently, the number of cells increased as a consequence of tumor growth. EAT cells did not induce influx of PMN leukocytes till six days after tumor implantation, but a significant influx was observed on the tenth day. Inoculation of the tumor cells did not induce production of H2O2 by peritoneal cells at any time examined and induced low levels of macrophage spreading only until the third day after tumor implantation but not later on. The levels of thromboxane in the peritoneal cavity were not affected by the presence of the tumor, whereas prostaglandin E2 levels were significantly increased at all times examined. The biological significance of these results on the evolution and escape of the tumor from host defense mechanisms is under investigation.

Animals↗