Effect of Escherichia coli alpha-hemolysin on human peripheral leukocyte function in vitro.

To gain further evidence for the role of the Escherichia coli alpha-hemolysin in pathogenesis, its in vitro effects on human peripheral leukocyte function were studied. Leukocytes exposed to low doses of alpha-hemolysin responded with a marked chemiluminescence response, indicating activation of oxidative metabolism. This response was time and dose dependent.

Effect of Escherichia coli alpha-hemolysin on human peripheral leukocyte viability in vitro.

To gain further evidence that Escherichia coli alpha-hemolysin has a role in pathogenesis, its effect on human peripheral leukocyte viability was studied in vitro. Viability of leukocytes exposed to low doses of alpha-hemolysin decreased nearly 10-fold within 15 min of exposure. This response was dose and time dependent and was neutralized by antiserum, heat, proteases, and lipase.

Cytotoxic activity of partially purified Escherichia coli alpha haemolysin.

Alpha haemolysin, produced by Escherichia coli, grown in a chemically defined medium, was purified 19-fold and the endotoxin content reduced 2176-fold by ultrafiltration and glycerol-gradient ultracentrifugation. Immunodiffusion of purified alpha haemolysin (PH) against antiserum to crude haemolysin (CH) revealed only one precipitation line. PH was cytotoxic in nanogram amounts for mouse-fibroblast 3T3 cells, and the cytotoxicity exhibited proportional dose-response and time-course kinetics.

[Acute respiratory syndromes caused by viruses in a pediatric department. Clinical and epidemiological studies of a series of cases admitted in the period from February to May, 1979].

In the period between February and May 1979, in concomitance with a sharp increase in admittance to the pediatric Division of the Parma General Hospital for acute respiratory infections, we carried out a virologic and serologic investigation on hospitalized children aged 21 days-12 years. The investigation was carried out on 137 patients with respiratory diseases: 33 with bronchiolitis, which occurred mainly (32/33) between February and March in children that were prevalently (30/33) in the first year of life; 27 with upper respiratory tract infections; 54 with mid respiratory tract infections; 23 with pneumonia. Forty-eight controls (without respiratory infections) were also investigated.

Detection of carriers and prenatal diagnosis for fucosidosis in Calabria.

A significant proportion of patients affected with fucosidosis have Italian ancestors. We assayed for alpha-fucosidase activity purified mononuclear cells and/or leukocytes obtained from 64 members of two large pedigrees from Calabria, in which seven children had been diagnosed as affected with fucosidosis. Of these 64 individuals, 22 were diagnosed as carriers, while the values for the remainder were within normal limits, indicating a clear bimodal distribution among individuals at risk.

[Mucolipidosis. biologic characteristics (author's transl)].

Mucolipidosis II is a severe inherited lysosomal storage disease characterized by profound psychomotor retardation, severe Hurler-like skeletal changes and normal urinary mucopolysaccharide excretion. Mucolipidosis II is a related disorder distinguished by its milder course, milder to absent mental retardation and survival to adult life. Cultivated fibroblasts from patients with both of these disorders display large inclusions on phase microscopy and reduced levels of many acid hydrolases.

Relationship between alpha-L-fucosidase deficiency in plasma and alpha-L-fucosidase activity in leukocytes.

After testing a population sample of 185 hospitalized Italian children for the plasma alpha-L-fucosidase deficiency and establishing an approximate threshold value between heterozygotes and wild-type homozygotes, we analyzed by two statistical methods the distribution of the two genotypes. The results obtained by probit analysis agree with threshold and average values expected on the basis of the Hardy-Weinberg equilibrium. In addition, the level of alpha-fucosidase in leukocytes of 12 individuals with deficiency of alpha-fucosidase in plasma was found to be significantly lower than that of 61 controls (P less than 0.

Sialidosis (mucolipidosis I).

The term "sialidosis" is suggested for the deficiency of alpha-neuraminidase activity in peripheral leukocytes and cultured fibroblasts which results in a considerable urinary excretion of sialyl-oligosaccharides. This defect was found in two siblings with a mild form of mucolipidosis I. 12 sialyl-acid rich oligosacharides have been isolated from the urine of the patients.