Dynamics of red fluorescent dental plaque during experimental gingivitis - A cohort study

Objectives The dynamics of red fluorescent plaque (RFP) in comparison to clinical plaque and bleeding scores were studied during an experimental gingivitis protocol in a cohort of healthy participants. Methods Forty-one participants were monitored for RFP before (24 h plaque), during 14 days plaque accumulation (days 2, 5, 9, 14) and after 7...

Linking phylogenetic identities of bacteria to starch fermentation in an in vitro model of the large intestine by RNA-based stable isotope probing

Summary Carbohydrates, including starches, are an important energy source for humans, and are known for their interactions with the microbiota in the digestive tract. Largely, those interactions are thought to promote human health. Using 16S ribosomal RNA (rRNA)-based stable isotope probing (SIP), we identified starch-fermenting bacteria under...

An in vitro model for detecting skin irritants: Methyl green-pyronine staining of human skin explant cultures

We evaluated the potential of human organotypic skin explant cultures (hOSECs) for screening skin irritants. Test chemicals were applied to the epidermis of the skin explants which were incubated for 4, 24 or 48 h in tissue culture medium. A decrease in epidermal RNA staining, visualised in frozen sections using a modified methyl-green pyronine ...

Changes in the nasal epithelium of rats exposed by inhalation to mixtures of formaldehyde, acetaldehyde, and acrolein

Formaldehyde, acetaldehyde, and acrolein are well-known upper respiratory tract irritants and occur simultaneously as pollutants in many indoor and outdoor environments. The upper respiratory tract, and especially the nose, is the prime target for inhaled aldehydes. To study possible additive or interactive effects on the nasal epithelium we...

Detection of thymine dimers in suprabasal and basal cells of chronically UV-B exposed hairless mice

An immunocytochemical method was developed to study induction and removal of DNA damage in specific cell populations in the epidermis of hairless mice during chronic ultraviolet (UV) exposure. Identification of mouse suprabasal cells was performed with an immunoperoxidase stain. This stain was shown not to affect the fluorescent nuclear stains,...

New immunoenzyme-cytochemical stainings for the in situ detection of epitope specificity and isotype of antibody forming B cells in experimental and natural (auto)immune responses in animals and man

Identification of cells in primate bone marrow resembling the hemopoietic stem cell in the mouse

The colony forming unit culture (CFU C) in the thin layer agar colony technique is considered to be representative for hemopoietic stem cells (HSC), according to studies in mouse and monkey bone marrow. Using this in vitro assay as a guide, stem cell concentrates were prepared from monkey and human bone marrow by repeated density gradient...