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Immunohistochemical stains fail to increase the detection rate of micrometastatic melanoma in completion regional lymph node dissection specimens.

In melanoma patients, examination of tissue sections stained for immunohistochemical markers as an adjunct to examination of haematoxylin and eosin (H&E)-stained sections has been shown to increase the detection rate of micrometastatic disease in sentinel lymph nodes (SLNs). However, immunohistochemical stains are not routinely performed on completion regional lymph node dissection (CLND) specimens in most centres and it is not known whether their use would increase the detection of micrometastatic disease in these specimens. This study was performed to determine whether the application of immunohistochemical stains for S100 and HMB45 (in addition to H&E stains) increases the detection of micrometastatic disease in CLND specimens of melanoma patients and whether their use would be cost-effective in routine pathological practice. Forty-nine CLND specimens from patients with a prior positive SLN biopsy were examined by performing H&E stains and immunohistochemical stains for S100 protein and HMB-45 on each node, and the detection rate of melanoma metastases using H&E-stained sections was compared with that using immunohistochemically stained sections. The number of nodes in the CLND specimens ranged from 4 to 37 (median 14, mean 14.7). Nodal deposits of melanoma cells were detected in 12 of 49 cases (24%). Among these 12 positive cases, the mean number of positive nodes per CLND specimen was 2.2 (range, 1-14). The total number of positive nodes in the 12 CLND specimens was 27, accounting for 3.8% of the 720 nodes removed in the study group of 49 cases. Melanoma cells in all 27 positive nodes were identified both on the H&E-stained slides and the slides stained immunohistochemically for S100. The melanoma cells were positive for HMB45 in 24 of the 27 lymph nodes that contained metastatic melanoma (the metastatic melanoma cells were negative for HMB45 in three positive nodes from one specimen). No further positive lymph nodes were detected with the immunostains that had not been identified on the H&E-stained sections. This study suggests that the use of immunostains does not increase the detection rate of metastatic melanoma in CLND specimens, and that their routine use would not be cost-effective. We therefore recommend only H&E staining on sections of all lymph nodes in CLND specimens from melanoma patients.

Humans↗

Cytologic detection of microsporidia spores in bile. A comparison of stains.

OBJECTIVE: To compare stains in preparations of bile in a patient with AIDS and microsporidial cholangitis. STUDY DESIGN: Bile was obtained from a 30-year-old male with AIDS and symptoms of cholangitis. Comparative staining of the specimen was performed using a formalin-fixed preparation stained with Chromotrope 2R stain and with alcohol-fixed preparations stained with Gram and Giemsa stain and Diff-Quik. An alcohol-fixed ThinPrep slide was stained with Papanicolaou stain. RESULTS: Diagnostic microsporidia spores were detected under oil immersion using Papanicolaou, Chromotrope 2R, Giemsa and Gram stain. The Diff-Quik-stained preparation also revealed microsporidia but with suboptimal morphology. CONCLUSION: Detection of microsporidia in bile can be achieved using several different stains routinely available to cytologists, most optimally with alcohol-fixed Papanicolaou- or Giemsa-stained preparations or with Chromotrope 2R stain, which is available in parasitology laboratories. These findings should be applicable to fluids from other body sites with this emerging pathogen in AIDS.

Adult↗

[Comparative analysis of macular hole surgery followed by internal limiting membrane removal with and without indocyanine green staining].

PURPOSE: To describe comparatively the outcomes of macular hole surgery followed by internal limiting membrane removal with and without indocyanine green staining. METHODS: We evaluated 142 consecutive macular hole surgeries with internal limiting membrane removal performed in the period from January 2001 to March 2004. These were divided into two groups, based on the use or not of indocyanine green staining. RESULTS: Both studied groups were similar concerning the patients' profile and preoperative stage of the macular holes. Mean preoperative visual acuity was 0.12+/-0.15 in the group with indocyanine green staining and 0.18+/-0.18 in the group without internal limiting membrane staining (p=0.02). Mean postoperative visual acuity was 0.27+/-0.27 in the group with internal limiting membrane staining and 0.43+/-0.25 in the group without internal limiting membrane staining (p=0.0002). We observed improvement of visual acuity in 63% of cases in the group in which internal limiting membrane staining was performed and in 80.3% of cases in the group without internal limiting membrane staining. Macular hole closure rates were 76.5% in the group treated with internal limiting membrane staining and 95.1% in the group treated without internal limiting membrane staining. CONCLUSIONS: Macular hole surgeries followed by internal limiting membrane removal without use of staining have better visual and anatomic results when compared to macular hole surgeries followed by internal limiting membrane removal guided by indocyanine green staining. We recommend caution in using indocyanine green staining in macular hole surgeries due to its possible toxic effect.

Adult↗

Thionin staining of paraffin and plastic embedded sections of cartilage.

The usefulness of thionin for staining cartilage sections embedded in glycol methacrylate (GMA) and the effect of decalcification on cartilage sections embedded in paraffin and GMA were assessed. Short decalcification periods using 5% formic acid or 10% EDTA did not influence the staining properties or the morphology of cartilage matrix and chondrocytes. The standard stain safranin O-fast green for differential staining of cartilage was used as control in these experiments. Prolonged exposure of safranin O stained sections to fast green resulted in disappearance of the safranin O stained matrix, thereby hampering the quantitative measurement of negatively charged glycosaminoglycans (GAG). Thionin stained evenly throughout all cartilage layers, independent of the staining times. In contrast to safranin O, thionin did not show metachromasia in nondehydrated cartilage sections, which made it more suitable for assessing cartilage quality in GMA embedded cartilage. To evaluate the selectivity of thionin staining in cartilage, chondroitinase ABC and trypsin digestions were carried out. Thionin staining was prevented by these enzymes in the territorial matrix, representing the interlacunar network and the chondrocyte capsule. Staining with thionin of the interterritorial matrix was only slightly reduced, possibly representing keratan sulfate and hyaluronic acid in cartilage of elderly patients. Comparison of thionin stained GMA embedded cartilage with safranin O stained paraffin embedded sections showed significant similarity in optical densitometry, indicative of the specificity of thionin bound to negatively charged GAG in cartilage. In GMA embedded cartilage morphology was relatively intact compared to paraffin embedded sections due to less shrinkage of chondrocytes and the interlacunar network.

Aged↗

Differential staining of two subpopulations of Purkinje neurons in rat cerebellum with acid dyes.

We present a new method that stains differently two subpopulations of Purkinje cells in the adult rat. Deparaffinized sections of cerebella, fixed by perfusion with buffered glutaraldehyde or Bouin's fluid were stained with 0.5% light green in 50% ethanol (10-30 min). The excess dye was removed with saturated aqueous picric acid (10-30 min). At this point some Purkinje cells appeared as lightly stained neurons, while others were strongly stained. Slides were immersed in 0.5% aqueous acid fuchsin for approximately 1 min until the lightly stained neurons acquired a red color. Following immersion in 1% phosphotungstic acid, slides were rapidly dehydrated in ethanol, passed to xylene and mounted in Canada balsam. Two subpopulations of Purkinje cells differing in their protein content in somata and proximal dendrites stained differentially by this method. They occurred in all coronal and sagittal sections and in patches or stripes. Their relative proportion varied from lobule to lobule. A second staining method used potassium permanganate as the sole staining reagent. The staining reagent can be used on sections previously stained with the acid dyes. Purkinje cells appeared as subsets of brownish to deep brown stained neurons, the latter ones corresponding to green stained cells in the dichromic method. The results obtained indicated that the subpopulations reflect real differences among individual neurons and are not artifacts. The technique holds promise for identifying and localizing sub-sets of Purkinje cells differing in their protein content under normal and experimental conditions and for their further characterization by combined staining and histochemical procedures.

Animals↗

Sirius red and acid fuchsin staining mechanisms.

The purpose of the study was to investigate the staining mechanism of acid fuchsin and Sirius red. Acid (poly-glutamic acid), neutral (poly-hydroxyproline) and basic (poly-arginine, poly-histidine, poly-lysine) poly-amino acids, collagen types I, II and III, and arginine- and lysine-containing histones were used as test substances applied to nitrocellulose membranes as dot blots. Five micrometer sections of granulation tissue on slides were tested in parallel. Some dots and sections were treated with chloramine-T before staining with acid fuchsin and Sirius red and some with 1 M NaOH after staining. The acid and neutral poly-amino acids were not stained, but the basic amino acids polylysine and poly-arginine, poly-amino acids containing these basic amino acids and the histones and the collagens exhibited intense staining. Oxidative deamination by chloramine-T abolished the staining and 1 M NaOH removed the staining except in the case of poly-arginine. Tissue sections treated in the same way showed a considerable decrease in staining after oxidative deamination with chloramine-T; in particular, the staining of the smaller fibers was abolished. The staining was totally removed by destaining with 1 M NaOH. Therefore, acid fuchsin and Sirius red are not selectively bound to collagen; they are also bound to other proteins containing basic amino acids, and staining to a large extent is influenced by electrostatic forces. The staining seems not to be selective for collagen, and one must account for this when quantitative conclusions are drawn from collagen methods using these stains.

Animals↗

Comparison of immunohistochemical and modified Giemsa stains for demonstration of Helicobacter pylori infection in an African population.

BACKGROUND: Modified Giemsa staining has been favoured by many researchers because it is easy to perform but, like many other stains, demonstration of the bacteria depends on its morphology. It has been arged in some research circles that some of the organisms in the gastric mucosa may not be true H.pylori. Immunohistochemical techniques have been developed and make use of anti H.pylori antibody, which reacts, with somatic antigens of the whole bacteria and have been found to correlate well with the presence of the bacteria. OBJECTIVE: To ascertain the efficacy of modified Giemsa stain in an African setting where H.Pylori seems quite prevalent. STUDY DESIGN: A laboratory-based study of two diagnostic tests in which modified Giema stain was compared with immunohistochemistry. METHODS: A total of 48 consecutive autopsy cases with no upper gastro intestinal diseases had their gastric mucosa stained for demonstration of H.pylori using both modified Giemsa and immunohisto chemical staining techniques. RESULTS: Twenty-seven cases of H.pylori were demonstrated by both techniques and 14 cases were not identified by the two staining methods. In 2 cases immunostain could not demonstrate the bacteria but they were identified with modified Giemsa stain while in 5 cases the bacteria were identified by immunostain but not with modified Giemsa stain. The sensitivity of modified Giemsa stain was 85% (CI 66.5-98.8) while the specificity was 89% (CI 60.4 - 97.8). The positive predictive value of modified Giemsa stain was 93% CI 75 - 98.8%) while the negative predictive value was 74% (CI 48.6 - 89.9). The kappa statistic comparing the 2 stains was 0.69 (p value 0.00001) giving a good agreement between the two tests. CONCLUSION: With the above results the modified Giemsa stain, which is readily available in most African laboratories, is recommenced for diagnosis of H.pylori, a prevalent infection in Africa.

Adolescent↗

The influence of Romanowsky-Giemsa type stains on nuclear and cytoplasmic features of cytological specimens.

The aim of the present study was to compare the staining pattern of the standard azure B-eosin Y stain with commercial May-Grünwald-Giemsa (MGG) stains on cytological specimens by means of high resolution image analysis. Several cytological specimens (blood smears, abdominal serous effusions, bronchial scrape material) were air dried, methanol fixed and stained with the standard azure B-eosin Y stain and with commercial May-Grünwald-Giemsa stains. Integrated optical density (IOD) and colour intensities of cell nuclei and cytoplasm were measured with the IBAS 2000 image analyser. Commercial MGG stains gave much higher coefficients of variation for all parameters than the standard stain. Reproducibility of cell nuclei segmentation versus cytoplasm was significantly better for the standard stain. Contamination of the standard stain with methylene blue partly copied the staining pattern of commercial stains. The standard azure B-eosin Y stain is recommended for high resolution image analysis (HRIA) of cytological samples.

Azure Stains↗

Only aldehyde fuchsin made from pararosanilin stains pancreatic B cell granules and elastic fibers in unoxidized microsections: problems caused by mislabelling of certain basic fuchsins.

The most distinctive property of aldehyde fuchsin is its staining of certain nonionic proteins and peptides in unoxidized cells and tissues. These substances include granules of pancreatic islet B cells, elastic fibers and hepatitis B surface antigen. Aldehyde fuchsin made from two different basic fuchsins, each certified by the Biological Stain Commission and labelled C.I. (Colour Index) No. 42500 (pararosanilin), did not stain pancreatic B cells at all. Stain Commission's records and retesting showed that each of the "faulty" basic fuchsins was not pararosanilin, but rosanilin, whose Colour Index number is 42510. These basic fuchsins were labelled with the wrong Colour Index number when packaged. Additional basic fuchsins were coded by V.M.E. and tested by R.W.M. for their capacity to make satisfactory aldehyde fuchsins. Only certain of these aldehyde fuchsins stained unoxidized pancreatic islet B cells. The same aldehyde fuchsins stained elastic fibers strongly. Each basic fuchsin whose aldehyde fuchsin was judged satisfactory proved to be pararosanilin. Aldehyde fuchsin solutions made from other basic fuchsins stained elastic fibers only weakly and did not stain pancreatic B cells at all in unoxidized sections. Each basic fuchsin whose aldehyde fuchsin was unsatisfactory proved to be rosanilin. It appears that only aldehyde fuchsin made from pararosanilin stains unoxidized pancreatic B cell granules dependably. We found that basic fuchsins from additional lots of Commission-certified pararosanilin and rosanilin were also labelled with incorrect Colour Index numbers when packaged. Steps were taken to prevent recurrences of such mislabelling which has made it difficult until now to correlate differences in the properties of pararosanilin and rosanilin. A table is provided of all basic fuchsins that have been certified by the Biological Stain Commission since 1963 when they began the practice of subdesignating basic fuchsins according to whether they are pararosanilins or nonpararosanilins. The consumer can readily determine from the certification number on the label the correct subdesignation of any Commission-certified basic fuchsin listed here. Until now, mislabelling of some lots of pararosanilin as rosanilin and vice-versa has confused and frustrated the users of basic fuchsins in other applications such as the carbol fuchsin staining of tubercle bacilli and certain cytochemical tests, e.g. esterase and acid phosphatase, that utilize hexazotized pararosanilin as a coupling reagent. Consumers experiencing trouble with any Commission-certified dye should look to the Biological Stain Commission for help. This is an important reason for purchasing, whenever possible, only Biological Stain Commission certified dyes.

Aldehydes↗

Cytochrome oxidase staining marks dendritic zones of the rat olfactory bulb external plexiform layer.

Cytochrome oxidase staining of the rat olfactory bulb external plexiform layer (EPL) produces a darkly stained intermediate zone bordered by lightly stained superficial and deep zones. Similar zonal staining was seen in cats, rabbits, and hamsters. These zones vary in relative thickness around the circumference of the olfactory bulb; the deep zone is proportionally thicker in the most dorsal and ventral parts of the bulb. Tufted cell somata are unevenly distributed within the EPL; the outer part of the EPL has more somata. The distribution of the cytochrome oxidase reaction product shows that the darkly stained intermediate zone is not produced by staining of tufted cell somata. Zones of cytochrome oxidase staining correspond to the sublaminar distribution of mitral and tufted cell basal dendrites. This was demonstrated by labeling mitral and tufted cells with small extracellular horseradish peroxidase injections and processing alternate sections for horseradish peroxidase and for cytochrome oxidase. Because there was cross-reaction of the cytochrome oxidase procedure with horseradish peroxidase, it was possible to trace many neurons through both series of sections. Middle tufted cells of the superficial EPL have basal dendrites confined to the superficial zone of light cytochrome oxidase staining. Internal tufted cells and middle tufted cells of the intermediate zone send their basal dendrites into the intermediate zone. One group of mitral cells (type I) has basal dendrites confined to the deep zone of lighter cytochrome oxidase staining. A second group of mitral cells (type II) and tufted cells of the intermediate EPL has basal dendrites primarily confined to the intermediate zone of dark cytochrome oxidase staining. The correlation of the enzyme staining with the dendritic laminar patterns supports the existence of three relatively distinct sublaminae in the EPL and supports the designation of two types of mitral cells. The staining pattern also provides an independent method for evaluating the sublaminae of the EPL without the necessity of labeling individual groups of cells. Finally, the staining pattern suggests that the intermediate zone of the EPL may be subjected to more tonic synaptic input, causing it to have an increased level of metabolic activity.

Animals↗

Detection of mycobacterial infections using the Dieterle stain.

Retrospective review comparing the modified Dieterle stain with standard acid-fast stains was performed on seven surgical pathology cases that contained culture-positive mycobacteria infections. Tissues examined comprised cervical and submandibular lymph nodes and soft tissues of the face and chest. Modified Dieterle staining was performed on paraffin-embedded tissue sections, and the results were compared with those of hematoxylineosin stains and auramine-rhodamines and carbolfuchsin acid-fast stains. The acid-fast stain showed organisms in three of seven cases on initial review and five of seven cases on retrospective review; the auramine-rhodamine stain retrospectively revealed organisms in five cases. In contrast, the Dieterle stain showed organisms in all seven sections on retrospective examination. Dieterle stains revealed either beaded bacilli or nocardia-like filamentous organisms, sometimes with abundant granular debris possibly representing degenerative organisms. In three cases in which bacteria were readily apparent with the Dieterle stain, only rare organisms could be identified with the acid-fast stain. The modified Dieterle stain was more sensitive than the acid-fast stain in the identification of mycobacteria in pediatric specimens, and its use is recommended in cases with necrotizing granulomas. However, its specificity is limited by morphologic similarities of the organisms to those of nocardiosis and cat scratch disease.

Adolescent↗

Immunohistochemical nuclear staining for p53, PCNA, and Ki-67 in different histologic variants of basal cell carcinoma.

BACKGROUND: Increased expression of p53 has been found in the majority of basal cell carcinomas (BCCs); however, UV-light-induced signature mutations are present in only about 50% of cases. Increased nuclear staining with an immunohistochemical marker of proliferation, proliferating cell nuclear antigen (PCNA), has been correlated with aggressive behavior in BCC. OBJECTIVE: Our purpose was to determine whether there is any relationship between different histologic variants of BCC and their expression of p53, PCNA, and Ki-67. METHODS: We used immunohistochemical stains for p53, PCNA, and Ki-67, in superficial-multicentric, nodular-noduloulcerative, sclerosing, infiltrative, and metatypical BCC, to determine whether the staining patterns differ in these different histologic variants of BCC. RESULTS: Superficial-multicentric BCCs were negative for p53 in four of eight tumors. Nodular BCC showed moderately intense p53 nuclear staining with some peripheral accentuation. PCNA nuclear staining was greater than Ki-67, and PCNA-positive cells were fewer than 10% in nodular BCC. Sclerosing and infiltrative BCC showed intense p53 nuclear staining with peripheral accentuation. PCNA nuclear staining was greater than Ki-67, and PCNA-positive cells were greater than 30% in the majority of these tumors. Metatypical BCCs showed diffuse intense p53 staining. PCNA nuclear staining was greater than Ki-67, and PCNA-positive cells were greater than 30% in all tumors studied. When overlying actinic keratoses showed p53 staining, the staining did not necessarily correlate with the intensity or even the presence of positive staining in the subjacent BCC. CONCLUSION: There are at least four distinctive patterns for staining of p53, PCNA, and Ki-67 that correlate with different histologic variants of BCC.

Biomarkers, Tumor↗

Validation of tissue microarray immunohistochemistry staining and interpretation in diffuse large B-cell lymphoma.

Tissue microarrays (TMAs) show concordance with whole tissue sections in the immunohistochemical evaluation of tumor cells. However, potential inter-institutional variability among observers and immunohistochemical staining methods has not been fully addressed. We selected 21 cases of diffuse large B-cell lymphoma (DLBCL) to process for TMAs. Immunohistochemical stains were performed in 3 laboratories, and reviewed independently by 3 hematopathologists at the 3 institutions. Stains were scored on a 4-point scale. Statistical analyses of variation in the scoring among observers and among different institutions' stains were performed. Stains for CD3, CD10, CD20, BCL-2, BCL-6, MIB-1, and FOX-P1 revealed little variation among observers, with an average 51-82% complete agreement and 82-100% agreement +/- 1 numerical score. The rate of concordance when evaluating most stains performed in different laboratories was also relatively good, with an average of 55-72% complete agreement and 70-97% agreement +/- 1 score. However, scoring of MUM-1 and p53 stains showed wider variation, with an average of only 37 and 30% complete agreement among observers, and 11 and 45% agreement when stains from different institutions were examined. Further statistical analyses were performed to compare the observers' scoring of their own institution's stains (self-review) vs. observers' scoring of other institutions' stains (non-self). The agreement rate for the p53 stain was significantly higher when based on self-review (average 58% complete agreement) compared with an agreement rate of only 10.5% when based on a review of stains performed in another laboratory, non-self review, P < 0.01. This difference in the self- vs. non-self review was not seen when data for MUM-1 were analysed. In conclusion, most phenotypic markers used in the analysis of DLBCL can be evaluated in TMAs with adequate agreement among observers and laboratories. These include CD3, CD20, CD10, BCL-2, BCL-6, MIB-1, and FOX-P1. However, some markers, such as p53 and MUM-1, are more prone to inter-institutional variation. Variations in interpretation can be partially overcome by self-adjusted/adapt tendency, as seen with p53. Especially with newly developed markers, such as MUM-1, the development of standardized techniques for staining and interpretation is critical to reduce inter-observer variability.

Analysis of Variance↗

Effect of resin surface sealers on improvement of stain resistance for a composite provisional material.

BACKGROUND: Resistance to staining is desirable to maintain the esthetic appearance of a provisional material. A resin sealant may improve stain resistance. PURPOSE: Color changes of a resin composite provisional material were measured by reflection spectrophotometry after storage in three staining solutions and water to determine stain resistance when treated with three methacrylate or urethane dimethacrylate resin surface sealants and when left untreated. MATERIALS AND METHODS: Specimens of a resin composite provisional material received one of three resin sealants (Fortify Plus, Bisco, Inc., Schaumburg, IL; Jet Seal, Lang Dental Manfacturing, Wheeling, IL; Triad LC, Dentsply International, York, PA, USA) or no surface sealer and then were stored for 72 hours in one of four staining solutions (water [control], black coffee, cranberry juice, red wine). Color was measured by CIE L*a*b* on a reflection spectrophotometer (Color-Eye 7000, Macbeth Division, Kollmorgen Instruments, Newburgh, NY, USA) at baseline and after storage. Color change (deltaE*) was calculated and analyzed statistically by two-factor analysis of variance, with four solutions and four surface treatments as independent variables. RESULTS: deltaE* ranged from 0.7 to 1.7 in water, from 1.1 to 5.5 in cranberry juice, from 1.1 to 6.5 in black coffee, and from 1.5 to 3.9 in red wine. Statistically significant differences were observed (p < .05), with Fortify Plus showing increased staining (deltaE* > 3.3) and Jet Seal and Triad LC showing decreased staining (deltaE* < 2.0) in cranberry juice and coffee compared with staining of the unsealed specimens. Only Jet Seal provided resistance to staining in red wine. CONCLUSIONS: Specimens without a surface sealer had statistically higher (p < .05) and perceptible or nearly perceptible color changes in cranberry juice, black coffee, and red wine than in water. Specimens coated with Jet Seal had statistically lower (p < .05) color changes than uncoated specimens in cranberry juice, black coffee, and red wine. When coated, the color changes of the stained specimens were not perceptible. Specimens coated with Triad LC had statistically lower (p < .05) color changes than unsealed specimens in cranberry juice and black coffee. When sealed, the color changes of the specimens stained with cranberry juice and black coffee were not perceptible. Both unsealed and sealed specimens stained with red wine were nearly perceptible. Specimens coated with Fortify Plus had statistically higher (p < .05) color changes than uncoated specimens in cranberry juice and black coffee but statistically the same (p < .05) color change as uncoated specimens in red wine. These specimens had perceptible color changes in cranberry juice, black coffee, and red wine. CLINICAL SIGNIFICANCE: Surface of methacrylate or dimethacrylate resins can improve resistance of a resin composite provisional material to staining caused by cranberry juice, black coffee, and red wine.

Acrylic Resins↗

A six-week clinical efficacy study of three commercially available dentifrices for the removal of extrinsic tooth stain.

The objective of this double-blind clinical study was to compare the extrinsic tooth stain removal efficacy of three commercially available dentifrices: Colgate Platinum Whitening Toothpaste with Fluoride, Aquafresh Advanced Whitening Toothpaste with Fluoride, and Crest Regular Fluoride Toothpaste. Following a baseline examination for extrinsic tooth stain, qualifying adult male and female subjects from the Toronto, Ontario, Canada are were randomized into three treatment groups which were balanced for age, gender, tobacco habits, and level of extrinsic tooth stain using the Lobene Stain Index. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice using a soft-bristled toothbrush. Examinations for extrinsic tooth stain were repeated after six weeks' use of the study dentifrices. One-hundred forty-nine (149) subjects complied with the protocol and completed the entire study. At the six-week examination, subjects assigned to the Colgate Platinum treatment group exhibited statistically significant reductions (p < 0.05) from baseline level with respect to extrinsic tooth stain area (49.4% reduction) and extrinsic tooth stain intensity (52.4% reduction). Statistically significant reductions (p < 0.05) for both extrinsic tooth stain parameters were also exhibited by the subjects assigned to the Aquafresh Whitening treatment group (14.0% reduction for area, 15.5% reduction for intensity). Both tooth whitening treatments provided statistically significantly greater reductions (p < 0.05) in extrinsic tooth stain than did the Crest Regular Fluoride dentifrice, which exhibited a small increase in the extrinsic tooth stain parameters over the course of the study. Additionally, the Colgate Platinum dentifrice provided statistically significantly (p < 0.05) greater removal of extrinsic tooth stain over the course of this six-week study than did the Aquafresh Whitening dentifrice. Thus, the results of the double-blind clinical study support the conclusion that the two tooth whitening dentifrices, Colgate Platinum and Aquafresh Whitening, provide significantly greater (p < 0.05) removal of extrinsic tooth stain than does Crest Regular Fluoride, a sodium fluoride/silica dentifrice. Further, the results of the study support the conclusion that Colgate Platinum dentifrice provides a greater (p < 0.05) level of extrinsic tooth stain removal efficacy than does Aquafresh Whitening dentifrice.

Adult↗

Neuronal populations stained with the monoclonal antibody Cat-301 in the mammalian cerebral cortex and thalamus.

The monoclonal antibody Cat-301 was used to examine neurons in the cerebral cortex and dorsal thalamus of several mammalian species, including Old World monkeys, cats, bush babies, guinea pigs, and rats. In each species, subpopulations of cortical and thalamic neurons are stained along the surfaces of their somata and proximal dendrites. Cat-301-positive cortical neurons include specific groups of pyramidal cells (e.g., corticospinal but not corticobulbar or callosal neurons in the monkey sensory-motor areas) and certain GABA-immunoreactive nonpyramidal cells. In the thalamus, the relay neurons projecting to the cortex and not the intrinsic neurons are stained. The Cat-301-positive neurons are nonhomogeneously distributed in the cat and monkey cortex and thalamus. In the cortex, they are densely packed in 2 bands that in most areas include layers III and V, but that in primary sensory areas include layers IV and VI. Because the density of stained neurons, their distribution, and the intensity of their staining vary among cortical areas, the borders between neighboring areas can often be detected by the differences in Cat-301 staining. Broader, regional differences are also readily apparent, for areas in the parietal and occipital lobes contain large numbers of intensely stained cells, but most areas in the frontal and temporal lobes contain fewer, more lightly stained neurons. The same broad differences are seen within the thalamus: only those nuclei reciprocally connected with intensely stained cortical areas contain large numbers of Cat-301-positive neurons. Differences among species include variations in cell density and distribution when a given cortical area or thalamic nucleus is compared between cats and monkeys. Greater differences are seen among the other species. Immunoreactive neurons in the cerebral cortex are sparse and lightly stained in guinea pigs, are restricted to the hippocampal formation in rats, and are very rare and isolated in bush babies. Similarly, Cat-301-positive thalamic neurons are restricted to only one or 2 nuclei in the guinea pig and rat and are extremely rare in the bush baby. Cat-301 stains organized groups of neurons in the cat and monkey cortex and thalamus. In addition to the laminar organization of stained cells in all cortical areas (see above), the Cat-301-positive neurons of monkey areas 17 and 18 are grouped into radial arrays. In area 17, clusters of stained cells are present in layers above and below layer IVC. These clusters lie at the centers of ocular dominance columns, within patches stained for cytochrome oxidase (CO). Most of these cells are also GABA-immunoreactive.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Acridine orange as a screen for organisms in clinical specimens and comparison with gram's stain.

We compared the result of acridine orange and Gram's stains with the results of culture for 202 wound swabs and 188 fluid specimens. Cerebrospinal fluid was excluded from the study. Acridine orange was more sensitive and less specific than Gram's stain compared with findings that have been previously reported. A difference in the sensitivity was observed between the two stains and between the types of specimens examined themselves. The sensitivity of acridine orange and Gram's stains was 83% and 49% for swabs and 66% and 45% for fluids, respectively. The negative predictive values for acridine orange and Gram's stains were 60% and 40% for swabs and 84% and 81% for fluids, respectively. Overall, the sensitivity for acridine orange and Gram's stains was 75% and 64% with negative predictive values of 75% and 63%, respectively; specificity was 75% (acridine orange) and 97% (Gram's stain) and did not differ significantly between the two specimen types. Acridine orange was cleaner, faster, easier to perform and read, and less costly than Gram's stain for screening purposes. Slides that were positive by acridine orange staining should be stained with Gram's stain for specificity and for the Gram's-stain reaction report. Acridine orange is recommended for screening smears, with positive results confirmed by Gram's stain.

Abscess↗

Use of environmental scanning electron microscopy to evaluate dental stain removal.

The purpose of the study was to assess the usefulness of environmental scanning electron microscopy (ESEM) to evaluate stain removal from extracted teeth. The ESEM differs from conventional SEM in that no sample preparation is needed, eliminating artifactual changes. Furthermore, the same sample can be viewed on multiple occasions, allowing "before" and "after" pictures of the same tooth. As a model stain removal device, we tested the Sonicare sonic toothbrush, which has previously been shown to remove dental stain in vivo. Twelve freshly extracted teeth with extrinsic coffee, tea or tobacco stain were obtained for the study. Nine of these had heavy stain (stain covering more than one-third buccal or lingual surface) and were used without further modification. Three teeth were treated in vitro with chlorhexidine and a mixture of coffee and tea to enhance staining. All teeth were examined by ESEM at three times: prior to brushing, after 15-30 seconds of brushing, and after 60-80 seconds of brushing. Light microscopy and 35 mm photography was also done to correlate the ultrastructural changes with those visible at low magnification. Water, mouthwash and 30% slurry of toothpaste were used as fluid vehicles during brushing, but little difference in stain removal was noted among these three fluids. Approximately half the stain was removed within 15-30 seconds, and most visible stain was removed in 60-80 seconds of brushing. Pits and crevices of tooth enamel that were smaller than the bristle diameter, and thus would be inaccessible to abrasive cleaning by direct bristle contact, were generally found to be stain-free. These findings confirm previous reports of the stain removal effectiveness of the Sonicare, and demonstrate the usefulness of ESEM for stain removal studies.

Chlorhexidine↗