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Biomedical subjects

M Barbi

Publications and source records attributed to M Barbi.

52 records · Page 3Linked to original sources
PubMed1979

Type 1 diabetes and Coxsackie virus infection.

The role played by viruses in the aetiopathogenesis of type 1 diabetes mellitus has been studied by several authors; in particular the importance of Coxsackie virus B4 infection has been stated by some authors and not confirmed by others. 43 diabetic children were studied at the time of the diagnosis of the disease. No viruses could be isolated from stools; the titres of anti-Coxsackie viruses B1 to 6 complement fixing antibodies and anti-Coxsackie virus B4 neutralizing antibodies, compared to controls, indicated that Coxsackie virus infection was not associated with the onset of diabetes in these children. A cross-reaction with anti-Coxsackie viruses sera and a human pancreas demonstrated that there are not antigens in common between these viruses and the human pancreas.

Adolescent↗
PubMed1978

Measurements of Euglena motion parameters by laser light scattering.

Measurements of Euglena gracilis motion parameters have been performed by the spectral analysis of the scattered laser light. Samples were oriented by a radiofrequency field to obtain easily interpretable spectra. Cell rotation frequency and flagellar beating frequency distributions were obtained from the homodyne spectra, whereas the Doppler lines obtained at small observation angles by heterodyne detection yielded the swimming speed distributions. We discuss the broadening of the heterodyne spectra at large angles of observation. An application of this method to the study of the photo-kinetic effect is also described.

Cell Movement↗
PubMed1978

Effects of electromagnetic fields on the motion of Euglena gracilis.

The orientation behavior of Euglena gracilis cultures in electromagnetic fields is shown to agree with the predictions of a model involving only a passive mechanism. The increase in Euglena motor activity with increasing field intensity is demonstrated by measuring various motion parameters by the laser scattering technique. The effect of electric field on the speed of Euglenas is compared with that of temperature. We conclude that the electric field warms up the culture, thus inducing an increase in cell motility.

Cell Movement↗
PubMed1977

Phase-locked responses in the Limulus lateral eye. Theoretical and experimental investigation.

The 1:1 phase locking of the neural discharge to sinusoidally modulated stimuli was investigated both theoretically and experimentally. On the theoretical side, a neural encoder model, the self-inhibited leaky integrator, was considered, and the phase of the locked impulse was computed for each frequency in the locking range by imposing the condition that the "leaky integral" u(t) of the driving signal should reach the threshold for the first time one stimulus period after the preceding impulse. As u(t) can be a nonmonotonic function, this approach leads to results that sometimes differ from those reported in the literature. It turns out that the phase excursion is often much smaller than the values of about 180 degrees predicted from previous analysis. Moreover, our analysis shows a peculiar effect; the phase locking frequency range narrows when the input modulation depth increases. The theoretical predictions are then compared with phase-locked discharge patterns recorded from visual cells of the Limulus lateral eye, stimulated by sinusoidally modulated light or depolarizing current. The phases of the locked spikes at each of a number of modulation frequencies have been measured. The predictions offered by the model fit the experimental data, although there are some difficulties in determining the effective driving signal.

Action Potentials↗
PubMedDate not supplied

Immunity to polioviruses and tetanus after bone marrow transplantation in children.

Immunity to tetanus toxoid and polioviruses was studied in 34 (27 allografted, 7 autografted) children who underwent bone marrow transplantation (BMT). At a median time of 3 years after BMT, only one recipient was seronegative for tetanus toxoid. On the contrary 73% of children were seronegative for at least one of the three poliovirus types and 30% for all virus types. Undetectable antibody titers were more frequently found against type 3 than the other two types. We recommend that reimmunizations of children after BMT be based on serologic tests for antibody titers.

Adolescent↗
PubMedDate not supplied

Sporadic cases associated with non polio enteroviruses studied in Lombardy between 1965 and 1972.

The results of virological investigations on 492 sporadic cases with a clinical diagnosis compatible with an enterovirus etiology studied in Lombardy between 1965 and 1972 are reported. A recent infection with non polio enteroviruses was established in 54 patients, mostly children under 4 years of age. Coxsackie viruses group A were prevalent being associated with 38 cases; echoviruses were involved in 13 cases, Coxsackie B viruses only in 3 instances. The frequency of isolation was highest from patients with paralytic illnesses either spinal or facial palsy than from patients with other diagnosis.

Adolescent↗
PubMedDate not supplied

[Sensorineural hearing loss in childhood: evaluation of economic impact in view of vaccine prevention of cases due to congenital cytomegalovirus infection].

Sensorineural hearing loss (SNHL) is a serious public health problem which affects 1-3% per hundred live born babies in developed countries. The congenital cytomegalovirus (CMV) infection is its most important non-genetic cause. The evaluation of the effectiveness of future programs of anti-CMV vaccination requires an assessment of the present costs of SNHL. Direct costs for the Italian public system were calculated per prosthesis child until his full age and turned out to add up to 260,000 euro. Private costs are difficult to be assessed and anyhow are highly dependent from the socio-economic level. This preliminary assessment suggests that the vaccination would be cost-saving if SNHL cases due to congenital CMV were more than 21 per year, corresponding to a congenital infection prevalence higher than 0.21%o.

Child↗
PubMedDate not supplied

[Interstitial pulmonitis due to the cytomegalovirus in an immunocompetent adolescent: treatment with ganciclovir].

Interstitial pneumonia is the most common disease caused by infection from cytomegalovirus (CMV) in immunodepressed patients, whereas it is a rare complication in immunocompetent patients. With reference to the second group of patients, little literature has been produced as for the therapy to choose when symptoms are serious. We report the case of immunocompetent adolescent with CMV pneumonitis who responded dramatically to therapy with ganciclovir. For a week B. M., a 15-year-old girl, has been showing fever, cough and boring pain at her left thoracic base. When hospitalized, the girl was suffering and dyspneic, cardio-thoracic conditions were bad. Spleen and liver were palpable two fingers far form costal arch. Hematochemical tests showed an increase in phlogosis and transaminase value. Thoracic X-ray was negative, as well as cultures. Among the serological tests high response of anti-CMV IgM was remarkable. Virological blood test confirmed active CMV infection. On the fifth day, a thoracic radiography showed widespread interstitial infiltrates. Treatment with ganciclovir--i.v. 6 mg/kg/day, twice a day for twelve days--has been then adopted. After two day treatment, the girls was apyretic and eupneic. After ten day treatment, thoracic radiography was negative and a great decrease in CMV antigenic response was given by blood tests. No side effect were observed. According to our experience we can say that treatment with ganciclovir may positively shorten the course of pneumonia caused by CMV in immunocompetent patients.

Adolescent↗