Reliability of acridine orange fluorescence microscopy in oral cytodiagnosis.

Context and Aims: The oral cavity is the most predominant location in the head and neck region for primary malignant epithelial tumors. Oral cancer is estimated to be the sixth most common malignancy. Early recognition is imperative for successful treatment and good prognosis. Exfoliative cytology is a simple and reasonably effective technique for rapid initial evaluation of a suspicious oral lesion. The present study was conducted to determine the reliability of acridine orange fluorescence microscopy for cytodiagnosis as a more rapid and easier method for the final evaluation of the cytological specimen. Materials and Methods: Smears were collected from 20 individuals with oral lesions suspicious of malignancy, oral lesions not suggestive of malignancy and normal buccal mucosa. One smear was stained with Papanicolaou stain and another one with acridine orange stain. The differences in the study group and control group were compared by means of the χ2 (Chi-square) test. The results were considered statistically significant whenever P was <0.05. Results: The acridine orange fluorescence stain reliably demonstrated malignant cells based on the differential fluorescence - a cytochemical criterion. The efficacy of the stain was higher than the conventional Papanicolaou stain in screening of oral lesions suspicious of malignancy. However, the acridine orange fluorescence stain did not differentiate effectively between malignant cells and rapidly proliferating cells, as the technique is based on the nucleic acid content. Conclusion: The fluorescent acridine orange method can be used reliably for the screening of carcinomas and it is especially helpful in the follow-up detection of recurrent carcinoma in previously treated cases.

Evaluation of the direct acridine orange staining method and Q.B.C. test for diagnosis of malaria in Delhi, India.

Conventional Giemsa stained peripheral blood smear examination for demonstration of malarial parasites remains the gold standard for diagnosis of malaria in developing endemic countries. However this technique is time consuming, requires training and may give poor results in cases with low parasitaemia. To overcome these problems and improve diagnostic accuracy two newer tests have been studied and compared with standard Giemsa staining. These are the wet mount fluorescence microscopy of Acridine Orange stained thin blood films (A.O.) and the Quantitative Buffy Coat technique (Q.B.C) for diagnosis of malaria. A.O. staining was found to be 97.5% sensitive and 100% specific for detection of all stages and species of malarial parasite. The Q.B.C assay was found to be 100% sensitive and 97.5% specific for diagnosis of malaria. A.O. staining was very fast and the species identification was easy once the staining was optimised. The Q.B.C. test required considerable amount of practice, costly equipment, however it was fast and in our study was found to be highly sensitive.

A comparative evaluation of four adhesive tooth coloured restorative materials. An invitro study.

Four adhesive tooth colored restorative materials, Fuji II, Fuji II LC, Dyract and TPH composite resin were evaluated for the amount of microleakage in enamel and cementum. The TPH composite resin showed maximum microleakage, significantly higher than Fuji II, which showed least microleakage. All the four materials showed more micro leakage in cementum when compared to enamel.

Evaluation of sperm nuclear DNA normality by acridine orange staining technique.

To determine the relationship between sperm deoxyribonucleic acid (DNA) normality and fertilizing potential, 93 semen samples from 48 fertile donors and 45 male partners of infertile couples whose major abnormalities in the female partner had been ruled out were studied. Semen samples were assessed for conventional parameters (volume, percentage of normal morphology, percentage of progressive motility, sperm concentration, and round cell concentration) according to World Health Organization (WHO) guideline and acridine orange staining. The mean sperm concentration, percentages of progressive motility, and percentage of green fluorescing sperm in semen were significantly higher in samples from fertile donors (p < 0.005). When the parameters of semen quality were considered normal according to the standard WHO criteria, the mean percentages of green-fluorescing sperm were significantly higher in fertile donors than infertile patients (65.6% vs 53.3%; p < 0.05). Therefore, the acridine orange staining technique for evaluation of the sperm DNA normality appears to give more information in infertile patients with normal semen analysis. It may be a useful addition to the conventional semen analysis.

Detection of Plasmodia in acridine orange stained capillary tubes (the QBC system).

The sensitivity, specificity and convenience of carrying out malaria diagnosis in acridine orange stained capillary tubes using a fluorescent microscope (the QBC system) was compared to screening for Plasmodia on conventional Giemsa stained thick smears. A dilution study revealed that the QBC is able to detect Plasmodia in as low a dilution as 5 organisms per ul. The QBC system was evaluated at a district hospital in Thailand. A preliminary study of 186 patients compared the QBC system to the routine malaria screening procedure (screening up to 30 microscopic fields on a thick smear). The sensitivity of the QBC was found to be 98.9% with a specificity of 94.4%. A second combined series of 465 febrile subjects were screened by thick smear and these results were compared to the QBC. 202 were positive for malaria on both QBC and thick smear. Sensitivity in this study was found to be 99.5% (202/203) and the specificity was 94.6% (248/262). When both series were combined, there were 14 QBC malaria positives that were not detected on thick smear, and 2 QBC malaria false negatives among the 651 patients studied. The parasite densities in these cases were between 10 and 320,000 organisms/microliters. The QBC system provided only a crude estimate of the level of parasitemia. The species of Plasmodia (P. falciparum and P. vivax) were correctly identified on QBC in 78% of cases.

Acridine orange stain--a rapid method for diagnosis of neonatal septicemia.

The present study included 150 newborns; 100 clinically septic and 50 clinically aseptic who served as control. Out of 100 clinically septic newborns, blood culture was positive in 33 (33%), serum CRP was positive in 64 (64%) and acridine orange stained buffy coat smear was positive in 76 (76%). Serum CRP was found to be the most specific (specificity 96%) and acridine orange stained buffy coat smear examination the most sensitive (sensitivity 94.3%) test for diagnosis of neonatal septicemia.