Molecular Epidemiology of Ampicillin-Resistant Non-β-Lactamase-Producing Haemophilus influenzae

Resistance to ampicillin without β-lactamase production is not a frequent occurrence among Haemophilus influenzae strains. This kind of resistance is encountered in unencapsulated strains isolated from bronchial secretions and ear, nose, and throat specimens and is exceptional in H. influenzae type b. We studied 29 of these strains from various areas in France and 2 reference strains. Strains were compared by using ribotyping, arbitarily primed PCR with two primers, and pulsed-field gel electrophoresis. Each technique enabled the identification of 20 to 23 different patterns among the 31 strains. The combination of the different patterns for the strains obtained by the different techniques provided 27 distinct profiles. According to these results, it seems that the clonal propagation of these resistant strains does not occur.     

Kinetics and properties of the cortisol-resistant lymphocyte population from lymph nodes of guinea pigs with experimental allergic encephalomyelitis

Lymphocytes from the cervical lymph nodes of guinea pigs were incubated in medium No. 199 for 24 h in the presence of cortisol in a concentration of 20 or 100 g%. The survival rate of the lymphocytes and their cortisol metabolism were determined and the nucleic acid content estimated cytophotometrically. A considerable decrease was found in cortisol metabolism by the lymphocytes from the 6th day after addition of an encephalitogenic mixture and there was a marked increase in the cortisol-resistant population of lymphocytes in guinea pigs with encephalomyelitis on the 17th–30th days after injection of the complete adjuvant. Cortisol in a concentration of 100 g% lowered the nucleic acid content of the lymphocytes of the intact animals but had no effect on lymphocytes of guinea pigs of the two experimental groups during the period of a considerable increase in the cortisol-resistant population. Progesterone depressed the lympholytic action of cortisol and the metabolism of this hormone by lymphocytes of intact guinea pigs. The ability of progesterone to reduce the lympholytic action of cortisol was weakened in guinea pigs with encephalomyelitis and guinea pigs receiving the adjuvant.Department of General Pathology, N. I. Pirogov Second Moscow Medical Institute. Allergologic Research Laboratory, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. D. Ado.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 200–202, February, 1977.     

Breast milk transmission of a Panton-Valentine leukocidin-producing Staphylococcus aureus strain causing infantile pneumonia

We report on a 38-day-old infant who developed pleuropneumonia due to a Staphylococcus aureus strain responsible for familial furunculosis, which was acquired by maternal breast-feeding. All isolates from the infant and parents were genetically related by randomly amplified polymorphic DNA analysis and produced Panton-Valentine leukocidin.     

Antigenic homogeneity among the adenovirus hexon types of subgenus C

Summary Antigenic relationships of hexons of human adenovirus (Ad h) types 1, 2, 5 and 6 of subgenus C were studied with 61 monoclonal antibodies (MAbs) raised against human Ad h1, Ad h35 and bovine adenovirus 2. The reactivity pattern (RP) and the titers of the MAbs were determined in indirect ELISA. In previous experiments with hexons of different subgenera 49 MAbs displayed numerous different intertype specificities besides genus specific and type specific ones. With the four hexon types of subgenus C all MAbs gave identical RPs except the type specific ones. Data reveal the existence of a remarkable homogeneity in the antigenic structure among the hexon types of subgenus C defined by the presence of identical or closely related intertype specific epitopes on the surface of the hexons. The possible significance of the results in the experimental gene therapy is discussed.     

Changes in amphetamine stereotypy in cats after electrical stimulation of the caudate nucleus

Two types of behavioral changes arise in cats after repetitive low-frequency stimulation of the head of the caudate nucleus in cats. Behavioral inhibition is more frequently triggered from the dorsomedial zone of the head, whereas activation phenomena precede depression during stimulation of the ventrolateral zone. The assortment and pattern of stereotyped movements following injection of the minimal effective dose of amphetamine vary in different ways against the background of these changes. After stimulation of the dorsomedial zones of the nucleus stereotypy is first disorganized and then weakened, whereas caudate activation is associated with strengthening of stereotypy.Department of Pharmacology, Chita Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 6, pp. 518–521, June, 1979.