Biomedical subjects
Publications and source records attributed to R Cavallo.
Anti-HIV antibodies were detected in postmortem blood and vitreous humor samples from 60 drug addicts died in 1988 and medicolegally autopsied at the University Institute of Forensic Science of Turin. Fifteen subjects were positive both in blood and in vitreous samples confirming the possibility to detect anti-HIV antibodies in vitreous humor in the screening of high-risk population.
Four methods to detect IgG antibodies to Epstein-Barr virus in serum samples of aspirate in renal transplant patients were evaluated. Further to technical characteristics, the assays were compared as to sensitivity, specificity and positive and negative predictive value. 100% of specificity was found for all methods whereas sensibility and negative predictive value were different among the different methods.
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Imipenem is a beta-lactam carbapenem antibiotic, N-formimidoyl thienamycin-derivate. Imipenem is highly active against gram-negative aerobes and also highly active against gram-positive aerobes and virtually all anaerobes, with MICs very low and MBCs equal or only two-four dilution higher, it has a low degree of affinity for all types of beta-lactamases, shown a good post-antibiotic effect, it is a potent inhibitor to peptidoglycan with a greatest affinity for PBP2 and PBP1, in gram-negative bacteria, and for PBP3, PBP1 and PBP4, in gram-positive bacteria. The precocious bactericidal activity belongs to its low molecular weight, the characteristic of zwitterionic compound, to its hydrophobicity and to, in finally, its compact molecular structure.
Based on the various viral properties, the recent Retrovirus classifications are reported. After describing the HIV characteristics with the transactivation capability, the authors include the HIV among the Lentivirinae.
Immunoglobulin G (IgG) and M (IgM) stability in serum samples collected on filter paper disks and stored at different temperatures was evaluated. IgG and IgM concentration measured by immunonephelometry was fairly stable for 4 weeks at 4 degrees C, whereas it decreased to about 50% of total at room temperature and at 37 degrees C. By ELISA, no significative loss in antibody activity of IgG was observed after 6 months at 4 degrees C. At 37 degrees C the loss was greater but still acceptable. Antibody activity of IgM decreased more rapidly than that of IgG: IgM were stable at -20 degrees C, whereas had a significative loss of activity after 5 weeks both at 4 degrees C and 37 degrees C. Finally, it is to note that a storage in saturated water vapour seems not to interfere with immunoglobulins stability.
Apneas in the different sleep states are commonly observed in the full-term healthy newborn infant. Central and short apneas prevail whilst apneas greater than 15 sec. are rare; a marked incidence of short apneas (less than 10 sec.) was observed in active sleep, even though apneas are not exclusive of active sleep. There is a strong inter-individual variability of apnea incidence. Apnea incidence in a state is not positively correlated to apnea incidence in different behavioural states: on the contrary there seems to be an opposite correlation between incidence in AS and QS. Apnea occurrence is positively correlated, in individuals, to the periodic breathing percentage. Apneas number and their duration is markedly lowered already in the second month of life. Periodic breathing must be considered a feature of immaturity. Obstructive apneas are less frequent than central apneas: their survey requires sophisticated technics with the aid of simultaneous recording of several breathing parameters. Relationship between central apneas/ obstructive apneas and mixed apneas is not known. Certainly obstructive and mixed apneas occurrence has been underestimated because of technical difficulties deriving from their survey. The meaning of an incidence of short apneas markedly higher than normal in full-term newborn infants is controversial and not clear, individuals with long apneas and subjects with short apneas in excess have been considered infants at SIDS risk. It is not clear whether periodic breathing and apneas depend on a common pathogenesis; the correlation between high incidence of periodic breathing in postnatal period and SIDS risk is still controversial. Few Authors suggest to treat newborn infants with extended apneas in sleep and considerable percentage of periodic breathing with aminophylline. The relation between gastro-oesophageal reflux and apnea has been recently evidenced. Central apneas and obstructive apneas during breast and bottle feeding have also been documented. Differently from pre-term infant apneas, bradycardia, although not exceptional, is not frequent during apneas in full-term newborn infants.
Cultures of Clostridium perfringens produce a factor which hydrolyzes phospholipids. In this paper we report the separation and the purification from the growth medium of Clostridium perfringens of two phospholipase activities: a specific sphingomyelinase, and a specific lecithinase. Both the phospholipase activities have been purified 300-fold by fractionation of the growth medium with ammonium sulfate, filtration on Sephadex G-100 and chromatography on DEAE cellulose. The sphingomyelinase activity is completely inhibited by 10(-3) M calcium chloride, hydrolyzed lysolecithin and dipalmitoyllecithin at about 10% of the rate of sphingomyelin. No hydrolysis of phosphatidylserine, phosphatidylethanolamine or phosphatidylinositol is detected. From the same growth medium a theta-toxin activity was also purified.
NK Lymphocytes were first identified by their cytotoxic and cytolytic activity against tumor cells. However there is now increasing evidence that these cells are also mediators of natural resistance against viruses, fungi, protozoa and bacteria. The purpose of this review is to summarize the data on the antimicrobial activity of NK cells and to discuss the influence of corticoids and of other molecules interfering with innate resistance against pathogenic micro-organisms.
The aim of this study was to determine the relationship existing between auditory disability, according to WHO 1980, and pure tone audiometry threshold in noise induced hearing loss. Disability was evaluated on the basis of a questionnaire submitted to 286 subjects with acoustic trauma. Answers obtained were considered reliable on the basis of statistical analysis. Results showed that subjects with disability have an higher pure tone threshold than subjects without auditory disability. However it appears difficult to determine a precise threshold level ever which auditory disability may be considered present. The Authors suggest that this limit could be determined on the basis of pure tone threshold at the 10th centile of the group of subjects with disability or at the 90th centile of subjects without disability.
HCMV infection is a major cause of morbidity and mortality following kidney transplantation. Clinical diagnosis is difficult, and rapid and sensitive diagnostic methods are needed since antiviral therapy is available. One hundred-forty-five consecutive kidney-transplanted patients were studied during a period of three months after transplantation. For laboratory diagnosis of HCMV infection, we looked for the presence of pp-65 antigen in polymorphonuclear leukocytes, HCMV-DNA and IgM. Demonstration of HCMV pp-65 antigen by immunofluorescence and HCMV DNA by PCR in leukocytes were efficient methods for early diagnosis of infection.
The protein encoded by the tumor suppressor gene p53 can complex and functionally interact with cytomegalovirus proteins produced during the immediate-early phase of infection. The functions of these complex are unclear but there is some evidence to suggest that binding of p53 to these viral proteins may inactivate p53 functions. Recent reports have shown that p53 is involved in regulation of transcription. In this study we have considered the possibility that p53 may regulate transcription of cytomegalovirus immediate early genes which play a crucial role for virus replication. Here we report that experiments in which NIH 3T3 cells were cotransfected with a p53 expression plasmid together with a reporter gene linked to the mouse cytomegalovirus immediate-early enhancer/promoter revealed that wild type p53 could efficiently reduce the transcriptional activity of this viral regulatory sequence. By contrast expression of a mutated p53 correlated with a much smaller reduction of transcription. Deletion mutants analysis of the enhancer revealed that repression of transcription by p53 requires a minimal promoter containing an SP1 consensus sequence and a TATA box.
The analysis of the MCMV IE enhancer revealed the presence of many putative binding sites for the transcription factors AP-1 and NFkB. Previous studies suggested that such factors represent a final target for the metabolic cascade triggered by serum and growth factors. On these basis we wanted to verify if serum stimulates the transcriptional activity of the MCMV IE enhancer through p21ras and AP-1 and NFkB according to the actual model of transduction of the mitogenic signal. Our data demonstrate that serum stimulates the MCMV IE enhancer through a pathway in which the p21ras is involded, as demonstrated by using the dominant inhibitory mutant ras(Asn 17). Moreover deletion mutant analysis of the enhancer showed that the serum responsive region lies between nucleotides -1280 and -285 and contains a high concentration of putative AP-1 and NFkB binding sites.
The immune response to viral infections is a combination of many events: viral antigen presentation to the immune system, proliferation of specific lymphocytes, cytokine intervention. This review describes the virus-cell relationship contributing to the latency state in viral infections (especially in AIDS) and cytokine network, its importance in the pathogenesis of viral diseases and its therapeutic potential.