Destructive effects of murine arthritogenic antibodies to type II collagen on cartilage explants in vitro

Certain monoclonal antibodies (mAbs) to type II collagen (CII) induce arthritis in vivo after passive transfer and have adverse effects on chondrocyte cultures and inhibit self assembly of collagen fibrils in vitro. We have examined whether such mAbs have detrimental effects on pre-existing cartilage. Bovine cartilage explants were cultured over 21 days in the presence of two arthritogenic mAbs to CII (CIIC1 or M2139), a non-arthritogenic mAb to CII (CIIF4) or a control mAb (GAD6). Penetration of cartilage by mAb was determined by immunofluorescence on frozen sections and correlated with changes to the extracellular matrix and chondrocytes by morphometric analysis of sections stained with toluidine blue. The effects of mAbs on matrix components were examined by Fourier transform infrared microspectroscopy (FTIRM). A possible role of Fc-binding was investigated using F(ab)2 from CIIC1. All three mAbs to CII penetrated the cartilage explants and CIIC1 and M2139, but not CIIF4, had adverse effects that included proteoglycan loss correlating with mAb penetration, the later development in cultures of an abnormal superficial cellular layer, and an increased proportion of empty chondrons. FTIRM showed depletion and denaturation of CII at the explant surface in the presence of CIIC1 or M2139, which paralleled proteoglycan loss. The effects of F(ab)2 were greater than those of intact CIIC1. Our results indicate that mAbs to CII can adversely affect preformed cartilage, and that the specific epitope on CII recognised by the mAb determines both arthritogenicity in vivo and adverse effects in vitro. We conclude that antibodies to CII can have pathogenic effects that are independent of inflammatory mediators or Fc-binding.

Multiplex binding modes of toluidine blue with calf thymus DNA and conformational transition of DNA revealed by spectroscopic studies

It is noteworthy to understand the details of interactions between antitumor drugs and DNA because the binding modes and affinities affect their antitumor activities. Here, The interaction of toluidine blue (TB), a potential antitumor drug for photodynamic therapy of tumor, with calf thymus DNA (ctDNA) was explored by UV-vis, fluorescence, circular dichroism (CD) spectroscopy, UV-melting method and surface-enhance Raman spectroscopy (SERS). The experimental results suggest that TB could bind to ctDNA via both electrostatic interaction and partial intercalation. The fluorescence quenching of TB by ctDNA was static and due to electron transfer from bases to the excited singlet state of TB. At low [TB]/[DNA] ratio, TB mainly partially intercalated into ctDNA resulting in the slight increase of base stacking degree; at high [TB]/[DNA] ratio, excessive TB externally stacked along the helix surface via coupling with partially intercalated ones, thereby inducing B-A transition of ctDNA. The conformational transition of DNA was confirmed by the obvious improvement of the thermal stability of ctDNA. The SERS spectra suggest that TB could partially intercalate into DNA basepairs with its ring C(1)NC(1') side buried.

Morphological and immunocytochemical investigations on mast cells in porcine ureter

Morphological, morphometric, histochemical and immunocytochemical investigations on mast cells, located in the wall of ureter of 8 months aged pigs were performed. Mast cells were found in all three layers of ureteral wall, but their distribution was irregular and the number unequal. It was established that alcian blue (AB)-positive mast cells were significantly more than toluidine blue (TB)-positive mast cells. A statistically significant smaller number of both AB and TB-stained mast cells were observed in the tunica mucosa. The largest number of mast cells was found in the tunica muscularis. In the adventitia, mast cells were higher in number in the main connective tissue than in the connective tissue near the blood vessels. Mast cells stained with TB showed variably expressed gamma-metachromasia, which was best visible in those situated in the lamina propria of the mucosa. The prevailing parts of mast cells, however, were AB-positive after AB-safranin staining. This was mostly found in mast cells of the tunica muscularis and in mast cells of perivascular location in the tunica adventitia. Immunocytochemically, mast cells were found to be positive for histamine and vasoactive intestinal polypeptide in the muscle coat, and to histamine in the adventitia, as well. On the basis of obtained results it was presumed that the mast cells in porcine ureter most probably took part not only in keeping of local homeostasis, but played also an important role of mobility of smooth muscle cells in the middle layer of ureter on one hand, and, on the other, in the adventitial blood vessels.

Analysis of RNA by analytical polyacrylamide gel electrophoresis

Polyacrylamide gel electrophoresis (PAGE) is a powerful tool for analyzing RNA samples. Denaturing PAGE provides information on the sample composition and structural integrity of the individual RNA species. Nondenaturing gel electrophoresis allows separation of the conformers and alternatively folded RNA species. It also can be used to resolve RNA protein complexes and to detect RNA complex formation by analyzing changes in the electrophoretic mobility of the RNA. RNA can be visualized within gels by different methods depending on the nature of the detection reagent. RNA molecules can be stained with various dyes, including toluidine blue, SYBR green, and ethidium bromide. Radioactively labeled RNA molecules are visualized by autoradiography, and fluorescently labeled RNA molecules can be observed with a fluorescence scanner. Generally, gels between 0.4 and 1.5mm thick are used for analytical PAGE. Gels thinner than 1mm are fragile and thus usually are not stained but rather are used for radiolabeled RNA. The gels are dried and the radiolabeled RNA is visualized by autoradiography.

Chromatographic, mass spectral, and visible light absorption characteristics of toluidine blue O and related dyes

Contrary to earlier literature reports, the impurities in toluidine blue O were shown by column chromatography, TLC, and mass spectrometry to be N-methyl homologs of 2-methylthionine rather than N-methyl homologs of thionine. Small amounts of 2-methyl-3-amino-7-methylaminophenothiazine and 2-methyl-3,7-diaminophenothiazine were identified in commercial samples of toluidine blue O. However, sample handling and a warm alkaline environment can cause rapid demethylation of the dye.

Improved demonstration of mast cells using alcian blue tetrakis (methylpyridium) chloride

Many batches of alcian blue dye are incompletely soluble at the low pH used for demonstrating mast cells. An improved technique using alcian blue tetrakis (methylpyridium) chloride (alcian blue pyridine variant) is described here. It produces stronger mast cell staining than other alcian blue stains tested.

[Toluidine blue in monitoring of recurrences and second primary tumors in patients treated for oral cavity and pharynx cancer]

Assesment of recurrences in the oral cavity and pharynx is a serious diagnostic challenge particularly in patient after surgery and irradiation. Observed visible local lesions like oedema, formation of postoperative scars and pain made the diagnostic procedure difficult. Sometimes it's impossible to distinguish recurrences and inflammatory reaction. The aim of this research was to evaluate the usefulness of toluidyne blue in monitoring of recurrences and second primary tumors in the patients with oral and pharyngeal cancer. It was perform by comparison of the three methods: physical examination, endoscopic ultrasound probe and toluidine blue staining in detection of early malignancy. A group of 80 patients with oral and pharyngeal squamous cell cancer was treated in the years between 2000-2003 in the Department of Otolaryngology in Poznań. In 7 positive tested cases toluidine blue staining was confirmed in histological examination. 3 cases were false-positive staining (patients after reconstructive with infrahyoid and pectoral major flap).

CONCLUSIONS

(1) toluidine blue staining is cheap effective diagnostic procedure in monitoring recurrences in patients after surgery and irradiation; (2) procedure is limited in patients after reconstructive flap surgery; (3) ultrasound endoscopy is of value in assesment of advanced tumors of oral cavity and pharynx, but it's limited in flat and superficial mucosal infiltrations.

An easy method to highlight chief cells in gastric biopsies

BACKGROUND

Hematoxylin and eosin (H&E) is not an optimal stain to discriminate chief cells from parietal cells in gastric biopsies

MATERIALS AND METHODS

Fifteen sets of biopsies from the gastric corpus were consecutively stained with H&E and toluidine blue stains; chief cells stained deep blue with toluidine blue, thus contrasting with lightly-stained parietal cells. In well-oriented sections, the continuity of the chief cell zone was studied at × 4 magnification and its thickness in one field at × 10 magnification.

RESULTS

Toluidine blue stained fundic sections that exhibited normal mucosa or chronic gastritis without glandular atrophy displayed a distinct deep-blue chief cell zone, intercalated between the lightly-stained parietal cells on top and the muscularis mucosae underneath (Group A). In chronic gastritis with focal glandular atrophy or focal intestinal metaplasia, at least one focally fragmented toluidine blue chief cell zone was seen (Group B). In one case with severe autoimmune gastritis and in a case with extensive intestinal metaplasia, an absence of toluidine blue chief cells zone was recorded in the entire section (Group C).

CONCLUSION

This quick and easy staining method made it possible to group sections from the gastric corpus into those with a continuous chief cell zone, with fragmented or with an absent chief cell zone, modalities that seem to correlate with different stages of fundic mucosal inflammation. These preliminary results should be validated in a larger cohort of gastric biopsies from patients with various diseases affecting the corpus mucosa.

[Determination of nucleic acids using toluidine blue as a fluorescence probe]

A new fluorimetric method has been developed for the determination of deoxyribonucleic acid (DNA) with toluidine blue (TB) as a fluorescence probe. It is based on the fluorescence quenching of toluidine blue in the presence of DNA. In Tris-HCl buffer solution (pH 8.5), the calibration graph was linear over the range 0.10-6.00 microg x mL(-1) for ctDNA, and the detection limit was 27 ng x mL(-1). The result of the determination of DNA of camphor tree's leaf by this method was satisfactory.