A COMPARATIVE STUDY OF DNA FLOW CYTOMETRY AND MICROSPECTROPHOTOMETRY IN GASTRIC CARCINOMAS

Flow cytometric (FCM) and microspectrophotometric (MSP) measurements of cell nuclear DNA content were made in 53 fresh gastric carcinoma specimens and in 30 gastric mucosal specimens with chronic gastritis. DNA aneuploidy was found in 32/53 (60%) of gastric carcinomas, and appeared more frequently in wellor moderately differentiated tubular adenocarcinomas (90%) than in undifferentiated and mucousa cell carcinomas (23.6%) (P【0.001). No aneuploidy was found in chronic gastritis samples, but their proliferative cell fractions were higher than in normal control gastric mucosa samples (P【0.01). A comparison was made between FCM and MSP analyses of DNA content in 29 cases of gastric carcinoma, a high correlation rate (r=0.90) was found. The advantages and limitations of both methods are discussed, they may be used in combination for more precise cytochemical analysis.

DNA Cytophotometric Measurements on Canine Stomach Carcinogenesis Induced by N-Ethyl-N'-Nitro-N-Nitrosoguanidine

Measurement of DNA content and nuclear area by microspectrophotometry was performed in gastric carcinogenesis of three adult wolfdogs induced by N-Ethyl-N’-Nitro-N-Nitrosoguanidine (ENNG) . The mean values and standard deviations of nuclear DNA and the lesions in the area of different groups were as follows: normal gastric mucosa 10.03±2.30 (arbitrary unit, AU) and 28.76±5.85 (urn2) , atrophic gastritis 12.04 ±3.34 AU and 28.69±8.02μm^2; mild dysplasia 13.52±3.73 AU and 28.23±8.12μm^2; moderate dysplasia 20.88±4.57 AU and 47.58± 10.74μm^2; severe dysplasia 24.01±4.48 AU and 56.64±12.53μm^2; well-differentiated adenocarcinoma 33.07±9.38 AU and 72.99±15.57μm^2, respectively. The nuclear DNA content and nuclear area showed a significant statistical difference between normal gastric mucosa and gastric carcinoma (P【0.01) . The nuclear area of gastric carcinoma increased with DNA content (r =0.73, P【0.01) , and the distribution patterns of DNA content in the histogram showed that diploidy was decreased and polyploidy was increased in cancer. These findings indicated that DNA ploidy patterns and nuclear area could be a useful index in differentiated carcinoma and precancerous lesions.

DNA CYTOPHOTOMETRIC MEASUREMENTS OF CANINE STOMACH CARCINOGENESIS INDUCED BY N-ETHYL-N'-NITRO-N-NITROSO GUANIDINE

Measurement of DNA content and nuclear area by microspectrophotometry was performed in gastric carcinogenesis of three adult wolfdogs induced by N-ethyl-N’-nitro-N-nitrosoguanidine (ENNG). The mean values and standard deviations of nuclear DNA and area in different groups of lesions were as follows: normal gastric mucosal 0.03±2.30 AU and 28.76±5.85 μm^2; atrophic gastritis 12.04±3.34 AU and 28.69±8.02/μm^2; mild dysplasia 13.52±3.73 AU and 28.23±8.12μm^2; moderate dysplasia 20.88±4.57 AU and 47.58±10.74 μm^2; severe dysplasia 24.01±4.48 AU and 56.64±21.53μm^2; well-differentiated adenocarcinoma 33.07±9.38 AU and 72.99±15.57μm^2, respectively. The nuclear DNA content and nuclear area showed a significant difference statistically between normal gastric mucosa and gastric carcinoma (P【0.01). The nuclear area of gastric carcinoma increased with DNA content (r=0.73, P【0.01), and the distribution patterns of DNA content in the histogram showed that diploidy was decreased and polyploidy was increased in carcinoma. These findings indicate that DNA ploidy patterns and nuclear area could be a useful index in differentiated carcinoma and precancerous lesions.

Genetic variation of Norway spruce clones regarding their natural durability, physical and chemical properties

Genetic variation of ten Norway spruce (Picea abies (L.) Karst.) clones regarding their decay resistance against brown rot fungi, as well as physical and chemical properties of clones were investigated. 31- year-old spruce clones: 26, 31, A10, A15, A7, B10, B15, B6, V7, V9 were selected across Latvia. The stem diameters of spruce clones varied between 13.0 and 20.9 cm. The wood density of clones ranged from 361 to 443 kg/m3. Klason lignin content, depending on the clone, was between 27.0%-28.9%. Cellular UV microspectrophotometry of the non-infected tracheids displayed the typical lignin distribution with highest absorbance values in the cell corners (abs280 nm 0.80) and compound middle lamellae (abs280 nm 0.48), while secondary wall showed lower lignin absorbance values (abs280 nm0.29 - 0.35). The deposition of phenolic extractives in ray parenchyma and epithelial cells of resin canals were emphasized by a significantly higher UV-absorbance (abs280 nm 0.68 to 0.78) when compared to the cell wall associated lignin. The content of acetone-soluble extractives of spruce clones varied between 1.1% - 1.8%. The x-value (natural durability) for all spruce clones after exposure to C. puteana and P. placentawas >0.90 (durability class 5, not durable). Most of clones after degradation by G. trabeum had x-value > 0.90 with exception of clones B15 and V9 that showed x-value ≤ 0.90 (durability class 4, slightly durable). Natural durability of spruce clones did not correlate with stem diameter, density, content of lignin and extractives.

An examination of handwritten signatures forged using photosensitive signature stamp

Signature examination is the most common examination performed by any document examiner.Determination of the authenticity of a handwritten signature on a questioned document is an important task for forensic document examiners in the forensic science field.As a result of continuous developments in technology,a signature stamp can now be created using a photosensitive seal to enable the reproduction of a handwritten signature.These stamps are commonly used in China and several other countries.In this study,10 types of black photosensitive stamp-pad ink,10 brands of fountain pen ink,15 types of black gel ink and six types of black erasable gel ink found on the Chinese domestic market were collected and 10 photosensitive signature stamps were created using the signatures of 10 people.Microscopic analysis,infrared(IR)and fluorescence analyses and microspectrophotometry(MSP)techniques were used to examine the resulting photosensitive signature stamp impressions when applied to printing papers,writing papers and invoice papers.By comparing the printing and spectral characteristics of the photosensitive signature stamp impressions with those of the signatures executed using the fountain pens,gel pens and erasable gel pens,it was possible to determine whether each signature was written or stamped using a photosensitive signature stamp.To validate these results,a 96.7%absolute accuracy and a 99.3%detection rate were achieved over a total of 150 blind tests conducted by five forensic document examiners,thus demonstrating that a combination of the four analysis methods used in this work can provide a more scientific approach and improve the accuracy and the detection rate of the examination process.

Main Anatomy Characteristics in Cell Wall and Lignin Distribution of Bamboo Culms(Pseudosasa amabilis)

The anatomy characteristics of cell wall and lignin distribution in different anatomical regions for 12-month-old bamboo species Pseudosasa amabilis was investigated.The lignin distribution was studied by means of optical microscope and confocal laser scanning microscope and the color reaction. In addition,the distribution of lignin in different tissues(fiber,parenchyma and vessel) was investigated by visible-light microspectrophotometry coupled with the Wiesner and Maule reaction.The cell walls of different tissues were all lignified and the lignin was widely distributed in different tissues, in which there was a difference between tissues and anatomical regions in lignin content.Guaiacyl lignin and syringyl lignin unit could be found in cell wall of fiber,parenchyma and vessel through Wiesner and Maule reaction and the absorbance peak of spectrum. There was no regular variation in lignin content with different radial location of culms and different location in fiber strands.The lamellation of the fiber cell wall was generally had as alternating broad and narrow layers with alternating low and high concentration of lignin.