A contiguous stretch of methionine residues mediates the energy-dependent internalization mechanism of a cell-penetrating peptide

Recently we characterized an unusual switch in the internalization mechanism of the monomeric and dimeric forms of the cell-penetrating peptide RDLWEMMMVSLACQY. Here, we observed both energy-dependent and energy-independent modes of peptide uptake by the target B-lymphocytes WI-L2-729HF2, suggesting that higher-order structure might modulate the action of this novel cell-penetrating peptide. In the present work, we propose a possible internalization mechanism for the dimeric peptide which involves an initial interaction with the cell membrane, followed by an energy-dependent internalization process which requires the contiguous Met(6-8) sequence.     

Lipolytic activity and radial daily growth rate changes during incubation of thermomyces lanuginosus on natural and synthetic fatty substrates

The aim of the study was to compare lipolytic activity and radial growth rate changes during the incubation of Thermomyces lanuginosus strains on natural (sunflower oil, soybean oil, rapeseed oil, and corn oil) and synthetic (tributyrin, Tween 20, Tween 40, Tween 60, Tween 80, and Tween 81) fatty substrata. The general lipolytic activity index decreased on natural substrata and increased on synthetic substrata during a five-day incubation period. The general daily growth rate changes were found to be similar on both natural and synthetic fatty substrates.     

A study of herpes simplex type 2 antibody status in groups of patients with cervical neoplasia in Czechoslovakia

Sera collected from patients with cervical epithelial atypia, carcinoma in situ and invasive carcinoma, as well as from control subjects, were examined for the presence of HSV-1 and HSV-2 antibodies. All these subjects came from one district of Prague. In agreement with results reported from other laboratories, the serological findings indicated that the prevalence of HSV type 2 antibodies was markedly higher in the groups of patients with different stages of neoplastic process in the cervix, than in control groups of comparable age and socioeconomic status. The geometric mean titres for both HSV type 1 and type 2 antibodies were higher in the invasive carcinoma patient group than in other groups of patients.     

Lymphocyte subpopulations in the surface secretion on the adenoid

The significance and protective efficacy of surface secretions on mucosal membranes in the upper airways are well recognized. The aim of our study was to reveal the role of the adenoids as a source of cellular components in the mucosal secretion. The adenoid removed because of its hypertrophy and the samples of surface secretions taken by "imprint method" described by Ebenfelt et al. from the group of 38 children were examined. By flow cytometry the lymphocyte subsets with following antigens: CD3, CD4, CD8, CD19, CD23, CD16+56, CD45RA, CD45RO, HLA-DR were analyzed. The results were compared between the groups of younger and older children and in the group of concomitant otitis media with effusion (OMS) and pure adenoid hypertrophy. The percentage of lymphocyte subsets in adenoid and secretion were similar, except for lymphocytes Th with memory phenotype which were more numerous in the adenoid and lymphocytes B CD23+ which were more numerous in the secretion. In the adenoid the percentage of T and Th lymphocytes increased with age and the percentage of B lymphocytes decreased. In the secretion the percentage of lymphocytes Th and B CD23+ was higher among older children. In cases of otitis media with effusion higher percentage of lymphocytes B (CD19+ and CD19+CD23+) and lower of lymphocytes Ts and Th with naive phenotype were observed in the secretion. In adenoid however lower percentage of lymphocytes B and higher of lymphocytes Ts was observed in cases of OMS.     

Infantile mitochondrial leucodystrophy - a case report

We retrospectively analyzed a case of a 7-month-old infant with a delay of psychomotor development, slow pupillary light reflexes, horizontal nystagmus, spasticity and bilateral optic nerve atrophy. At the end of life there were problems with swallowing. Ventriculography showed widening of the lateral ventricles and atrophy in the frontal lobes. EEG revealed generalized changes. Clinically, leucodystrophy was diagnosed. General autopsy revealed cardiac hypertrophy. Neuropathological picture showed orthochromatic leucodystrophy with some features characteristic of neuropathology of mitochondrial disease: capillary hyperplasia and hypertrophy, spongiosis and symmetrical, bilateral damage of brain stem structures. The last one is characteristic of Leigh syndrome. Electron microscopic evaluation showed abnormal mitochondria, myelin and neurofibrils destruction. Hypertrophy of the heart may be also connected with mitochondrial disease.