Isolation and characterization of chitin from bumblebee (Bombus terrestris).

Insect chitin possessing shell-like structure was prepared from the bumblebee corpses by a consequent treatment with 1M HCl and 1M NaOH. The bumblebee chitin was compared with crustacean (shrimp) chitin by using elemental analysis, Fourier-transform infrared (FT-IR) and solid-state (13)C cross-polarization magic angle spinning nuclear magnetic resonance (CP/MAS)-NMR spectroscopy and confocal microscopy. Both chitins (bumblebee and shrimp) exhibited identical spectra, while the bumblebee chitin had a 5% lower degree of acetylation and was characterized by a fine membrane texture.

Cytostatic peptide isolation from culture media of mouse peritoneal exudate cells.

It was found that the supernatant of mouse PEC culture medium (MCM) (both resident and casein-elicited cells) has an inhibitory effect in vitro on the incorporation of [3H]TdR into DNA of mouse spleen cells. The inhibitory effect in the MCM appears in the first 24 hr and also reaches its maximum value within this time. The inhibitory effect of this factor could not be demonstrated in the extract of freshly harvested M phi cells.

Acidic acetone extract from pregnant sow ovaries is a rich source of substances affecting uterine contractility in vitro.

Acidic acetone extract of pregnant sow ovaries was subjected to Sephadex G-25 chromatography. The solution coming from column was analysed for UV absorption, molecular weight, and also for its biological effect on a myometrium strip in vitro. This biodetection system has made it possible continuously to determine the biologically active fractions eluted from the Sephadex G-25 column.

Possible role of peptides derived from otosclerotic bone in the mechanism of sensorineural hearing loss.

Otosclerotic stapes footplates, superstructures and temporal cortical bones were extracted with 0.25 M guanidine X HCl 0.5 M EDTA (pH 7.

Non-collagen proteins of stapedial bone matrix in perilymph of otosclerotic patients.

Non-collagen proteins extracted from the otosclerotic stapes footplate, superstructure and temporal cortical bone were compared with the protein patterns of normal and otosclerotic perilymph by analytical isotachophoresis (ITP). Normal and otosclerotic perilymph yielded basically identical isotachophoretic subfractions. Thirteen subfractions were detected moving as anions at pH 9.