Biomedical subjects

M Resti

Publications and source records attributed to M Resti.

61 records · Page 4Linked to original sources

PubMedDate not supplied

[Biology of human immunodeficiency virus infection].

This review will describe the current state of basic knowledge on the acquired immune deficiency syndrome (AIDS), which has now spread worldwide becoming an acute public health problem in western countries and in Africa. AIDS is a viral infection, due to a retrovirus designated human immune deficiency virus (HIV), which affects the immune system resulting in a wide array of secondary manifestations which include opportunistic infections, neoplasia, autoimmune phenomena, neurologic disorders, and hematologic abnormalities. AIDS has now been recognized in the pediatric population, and infection occurs by perinatal and blood-borne transmission. As a consequence, pediatricians are no more involved only by a theoretical point of view (AIDS is a perfect model of interaction of virus with the immune system), but also by an operative point of view. Knowledges on immunological modifications in AIDS and on the underlaying features of the HIV are essential for the clinical approach. This goal may be difficult, if one considers that the pace of research in AIDS and the progress attained to date are unprecedent. However, clinicians must be aware that the ultimate solution of clinical problems in AIDS exclusively depends on sound basic research.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

[Subclasses of IgG: biological aspects and functional behavior in response to vaccination].

The IgG subclasses are known to have different structure and functions. The IgG1 and IgG3 bind to monocyte and neutrophils and activate the complement more easily then IgG2 and IgG4. The levels of IgG subclasses found in newborns are mainly determined by the transplacental passage since the synthesis, in the first time of life, is very low. The levels found in adults are reached only during the adolescence. The immune response to a protein antigen is mainly in the IgG1 subclass, on the contrary the response to polysaccharide antigens is mainly IgG2. For that reason children, who produce very few IgG2 till they are 2 years old, cannot be vaccinated with carbohydrate vaccines unless a protein conjugate vaccine is used. In addition, the route of subministration, the dose of antigen, the age of vaccinated people and genetic factors can modify the subclass pattern obtained in response to vaccinations. For these reasons, probably, the immune response studied after a vaccination or in individuals who recovered from a natural disease is not always the same. Since the role of the different subclasses is not yet completely clarified, the interpretation of the importance of a selective "choice" of a subclass instead of another after vaccination is still difficult.

Aging↗

PubMedDate not supplied

[Active and passive immunoprevention of hepatitis B in newborn infants with HBsAg-positive mothers].

Infants born to HBsAg-positive mothers are at high risk of contracting perinatal hepatitis B infection. The prevention is based on active as well as passive immunoprophylaxis. We have used hepatitis vaccine in 18 newborns of as many HBsAg-positive mothers. Some haematologic and immunologic parameters are here reported. No alterations were observed as to liver function. Immunoglobulin values were normal for age. Auto-antibodies and rheumatoid factor were constantly absent. Immunecomplexes were present in the serum of some infants. The study of T cell subsets and of natural killer cells activity did not reveal any important changes, whereas minor modifications were present in polymorphonuclear leucocyte function. In all infants submitted to vaccination serum conversion was observed a with different antibody levels.

Female↗

PubMedDate not supplied

[Reduced natural killer function in children with recurrent respiratory tract infections].

Respiratory infections are the major cause of disease in childhood in the industrialized areas of the world. This essentially depends on two factors: immunological immaturity and immunological naivety. In most cases a virus has been considered the causative agent in respiratory infection. A defect in immune responses has been described in children with recurrent respiratory infections and in particular a decrease in CD4/CD8 T lymphocyte ratio or in IL-2 and IFN-gamma production. Our results show that Natural Killer (NK) cell activity is defective in children with recurrent respiratory infections. That is particularly noteworthy since NK cells play an important role in host defense against viral infections. At present it is difficult to understand whether the NK defect is a primary defect or it is secondary to viral infections. Further studies will help to clarify whether NK decreased activity depends on a cell damage directly caused by virus or it depends on the decreased levels of cytokines.

Adolescent↗

PubMedDate not supplied

[Gastroesophageal reflux and respiratory pathology].

The prevalence of gastroesophageal reflux (GER) in 86 children with respiratory disease (recurrent pneumonia, chronic cough, bronchial asthma) has been evaluated by mean of prolonged (22-24 hours) esophageal pH-monitoring. The following parameters were evaluated: the total percentage of time pH < 4 and the percent time the esophageal pH was < 4 while sleeping. None of the children had gastrointestinal symptoms suggesting GER and no neurological disorder was noted in any of the studied patients. The mean age was 68.98 +/- 46.46 months (range 14-189); 53 (61.6%) males and 33 (38.4%) females were considered in the study. Atopy was evidenced in 42/86 (48.8%) children (total IgE > 2SD in 42/86 and prick tests positiveness in 32/86. A pH-metry indicating pathological GER was present in 52/86 (60.5%) children: 39/62 (62.9%) patients with bronchial asthma, 5/10 (50%) subjects with chronic cough and 8/14 (57.2%) children with recurrent pneumonia. No significant difference in the diagnosis of GER was recorded between atopic or non-atopic patients. The children with abnormal pH-metric recording were also evaluated by upper gastrointestinal series and/or endoscopy. A conventional barium radiology was performed in 44/52 patients and confirmed GER in 19/44 (43.2%). Esophagitis was evidenced in 21/46 (45.7%) studied patients. The presence of esophagitis was significantly (p = 0.032) related to the total percentage of time pH < 4, but the most significant (p = 0.002) association was with the percent time the esophageal pH was < 4 during sleep.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

[IgG subclasses against bovine alpha-lactalbumin and beta-lactoglobulin in infants fed with a seroprotein hydrolysate].

Prevention of food allergy in infancy has been the aim of important researches in the last years but many studies have produced conflicting conclusions. The use of hydrolysate formulas seems to be an helpful tool in prevention of cow milk protein allergy but confusion often remains about capability of small hydrolysate molecules to be "allergens" or "antigens". In order to clarify this point IgE, IgG and IgM as well as IgG subclasses against alfa-lactoalbumin (ALA) and beta-lactoglobulin (BLG) have been evaluated in 41 infants at risk for allergy and in 30 controls at the fourth month. The same evaluation has been done on their mothers. The 41 "at risk" children were fed with breast milk or with an hypoallergenic formula (Nidina HA, Nestlè) or both. The control children received an adapted formula. No difference between the two groups of children was found regarding IgM or IgG against ALA while antibodies against BLG were more frequently found in controls than in "at risk" children. Only one child in the group fed with Nidina HA developed specific IgE against whole milk. Therefore hydrolysate formula seems to be as antigenic (not allergenic) as adapted formula in respect of ALA while BLG contained in adapted formula seems to be a stronger immunogen. The pattern of specific IgG subclasses against ALA and BLG is different between the two groups of children because of the absence in "at risk" group of specific IgG2 and IgG3. As for the mothers, the presence in their sera of IgG against ALA or BLG seems to induce in infants a reduced response to the same antigen.

Albumins↗

PubMedDate not supplied

[Hepatitis B virus: new markers and their immunology].

Hepatitis B virus (HBV) is one of the most important causes of chronic liver disease. HBV is a DNA virus with an external glycoprotein surface and an internal nucleocapsid which contains the viral genome. HBV infection is revealed by the appearance of specific markers. Some of these markers are well known and their presence in serum is important to understand the behaviour of the disease. Among them HBsAg, HBeAg, anti-HBs and anti-HBe are found in serum, so as anti-Core; the HBcAg may be found in hepatic tissue and marks infectivity and virus replication. In the few last years some new antigens and antibodies have been studied and their importance in diagnosis and follow-up of hepatitis has been recognized. HBxAg, Pre-S and DNA-Polymerase (Pol) seem to be specific and early signals of viral replication. More studies showed the trans-activating properties of HBxAg; actually the X protein seems to be involved in replicative cycle of HBV. Many Authors also demonstrated a relationship between the presence of X in serum and/or liver and the progression of disease to cirrhosis and hepatocellular carcinoma. The Pol antigen and its antibody seem to be very common markers of HBV infection in serum of patients with hepatitis. Moreover their presence is the only signal of viral infection in some patients which have no other marker of HBV. More studies are of course needed to exactly establish the significance of these new markers and their importance for diagnosis and prognosis of HBV infection.

Animals↗