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At least 19 recordsLinked to original sources
PubMed1981

Neural crest formation in the head of the mouse embryo as observed using a new histological technique.

A histological technique is described which results in the differential staining of neural crest cells. This is used to describe the formation and early migration of crest cells in the head of the mouse embryo. The first indications of crest formation are seen in the midbrain/anterior hindbrain at 3--4 somites where crest cells accumulate in the basal surface of the ectodermal epithelium near the future margin of the neural plate. Shortly thereafter (4--6 somites) these cells disrupt the basal surface of the epithelium and escape as mesenchyme. The apical epithelial cells in this region become the surface ectoderm adjacent to the neural plate. Subsequently, crest is formed from neural plate rather than surface ectoderm. In addition, mesenchyme is formed from presumptive surface ectoderm in a groove in the lateral portion of the fold between the forebrain and the midbrain. By 5--7 somites, crest mesenchyme is formed at all levels of the midbrain, hindbrain, and from the margins of the forebrain adjacent to the optic pits. Because of the bending of the embryonic axis, forebrain crest cells appear to migrate dorsally over the presumptive eye where they are met by ventrally migrating midbrain crest cells. Crest formation continues in the region of the midbrain and hindbrain during, and for an undetermined period after closure of the head folds at between 8 and 16 somites. These results demonstrate differences in the origin and timing of crest formation between chick and mouse. From this may be inferred different patterns of crest migration as well. In addition, the ability to directly observe early crest formation should aid in the analysis of the mechanisms by which epithelial cells are converted into mesenchyme.

Animals↗
PubMed2006

A reinvestigation of murine cranial suture biology: microcomputed tomography versus histologic technique.

BACKGROUND: Histology remains the standard form to analyze cranial suture in murine models, but this technique provides only limited "snapshots" of the entire suture and requires animal euthanasia with tissue destruction. Because of the bone complex microarchitecture, better methods are required to study the behavior of the cranial suture and its surrounding environment. The authors compared microcomputed tomography and histology as techniques to evaluate murine cranial sutures. METHODS: A total of 360 microcomputed tomography images and 160 to 170 histologic sections were processed from a mouse at postnatal days 22 and 45, respectively. After euthanasia, the posterior frontal and sagittal sutures were imaged with a microcomputed tomography system and subsequently processed for histologic analysis. Quantitative analysis of two-dimensional images was performed to determine the percentage of bone in a 1-mm sample. RESULTS: Quantitative analysis of the percentage of bone within the sutures showed identical patterns by microcomputed tomography and histology techniques. Both methods demonstrated the posterior frontal suture to have heavier fusion patterns in the anterior and endocranial portions, with variable skip areas of complete patency on the endocranial surface, ectocranial surface, or both at day 45. CONCLUSIONS: Cranial suture fusion in the murine model is not an "all-or-none" phenomenon. The posterior frontal suture, previously thought to be completely fused on day 45 by histological analysis, showed variable fusion along the length of the suture by both methods. Quantitative assessment of the percentage of bone within the posterior frontal and sagittal sutures and morphologic assessment of these sutures demonstrated similar findings by both methods. Whereas thorough histologic evaluation of an entire suture would be extremely labor intensive and impractical, these findings help to validate microcomputed tomography as a rapid and reliable method of examining the entire suture in murine models.

Animals↗
PubMed1996

Detection of multiple bloodfeeding in Culiseta melanura using a histologic technique.

We used a histologic technique to detect multiple bloodfeeding in a single gonotrophic cycle by Culiseta melanura. In a laboratory study with colonized mosquitoes, 77% (10/13) of known multiple meals were detected when the interval between meals was 24-30 h. Outside that range, known multiple meals were undetectable with this method. No multiple blood meals were detected in 653 wild engorged mosquitoes collected during 3 consecutive years from the Pocomoke Swamp in Maryland. Although previous studies have shown that Cs. melanura will feed twice in the same evening, it rarely, if ever, takes multiple blood meals at 24-h intervals. Our study also indicates that a thorough laboratory standardization is required prior to application of the histologic technique to species for which it has not been studied. This would include a time-series analysis to define species-specific limits for detecting known multiple meals.

Animals↗
PubMed1993

Detection of multiple blood feeding in Aedes aegypti (Diptera: Culicidae) during a single gonotrophic cycle using a histologic technique.

We evaluated a histologic technique for its usefulness in detecting multiple blood feeding by Aedes aegypti (L.) in a single gonotrophic cycle. To standardize the procedure, we carried out a laboratory study in which 166 mosquitoes imbibed two blood meals at known intervals. Eighty percent (78/98) of the multiple meals were detected when the interval between meals was from 1 to < to = 24 h and the time from the second meal to fixation ranged from 0 to 12 hr. At intervals outside this range, only 34% (23/68) of the multiple meals were detected. Overall, 61% (101/166) of the double meals were detected. Examination of 96 engorged Ae. aegypti collected by aspiration from inside houses in San Juan, Puerto Rico, indicated that 50% had imbibed multiple meals. Most wild-caught mosquitoes took their last meal the day before capture, and most multiple feeders fed twice on consecutive days. A dark line of digested blood, or heme, around the first meal and a physical separation between meals were the most useful histologic parameters for detecting multiple feeding in wild Ae. aegypti. An association of multiple feeding with advanced stages of oocyte development suggests that, at the time of collection, most Ae. aegypti from the study site had fed twice in each gonotrophic cycle. We conclude that, although it is labor intensive, histologic examination is an appropriate technique for a longitudinal, community-wide survey of multiple feeding by Ae. aegypti.

Aedes↗
PubMed1991

Quantitative histology of the rat thyroid. Influence of histologic techniques on the morphometric data.

The influence of various histologic techniques on the results obtained by morphometric analysis of the rat thyroid gland was studied. The limits of thyroid follicles were more clearly defined in both silver-impregnated paraffin-embedded sections and resin-embedded semithin sections than in routinely stained paraffin-embedded sections, thus enabling more accurate measurements of thyroid structures. Due to its simplicity, the silver impregnation method is clearly useful for histomorphometric studies when large numbers of measurements are involved. C cells were easily identified in paraffin-embedded sections by immunohistochemical staining. The measurement of interstitial tissue in sections without immunostaining of C cells led to an overestimation of the volume fraction of interstitial tissue.

Animals↗
PubMedDate not supplied

Precise diagnosis of infection in burn wound biopsy specimens. Combination of histologic technique, acridine orange staining, and culture.

This study developed a rapid manual histologic technique on burn wound biopsy specimens for an early diagnosis of infection. A total of 86 biopsy specimens were processed using this rapid manual method, acridine orange fluorescent staining for the detection of microorganisms, and a quantitative culture for the identification and counting of bacteria in adjacent homogenized biopsy specimens. Use of these three techniques has shown their complementarity for the evaluation of sepsis in burn wound patients. The histologic study allowed a classification of the depth of bacterial involvement 4 hours after specimen collection, whereas the acridine orange fluorescent staining was useful for quantitative evaluation of infection in the same delay. Thus a rapid therapeutic decision can be made while waiting for the results of quantitative culture and sensitivity tests, which require 24 to 48 hours. We propose routine monitoring of burned patients consisting of these three tests performed simultaneously on each biopsy specimen.

Acridine Orange↗
PubMed2001

Histological techniques and microscopic analysis of biological agents for preservation of human bone remains.

Microscopy and histology techniques can be applied to morphological study of fungi and bacteria contaminating ancient human osteological remains. Undecalcified samples are cut with a diamond rotary blade microtome and an original technique was applied using adhesive tape to prevent damage to the bone surface during sectioning. We used light microscopy, polarized light microscopy, and epi-illumination fluorescence systems. Common dyes can be applied to 80 microm sections using classic staining techniques to reveal the architecture of bone and the presence of infecting biological agents.

Bone and Bones↗
PubMed2005

Modified histologic technique for processing metallic coil-bearing tissue.

We developed a modified paraffin-embedding histologic technique for processing metallic coil-bearing aneurysm tissues. This modified technique was successfully employed for processing platinum coil-bearing tissue for 30 rabbit aneurysms and 6 swine aneurysms. This technique for sectioning coil-bearing aneurysms resulted in little or no tissue distortion and permitted good preservation of morphology and application of multiple advanced staining techniques. This technique is considered beneficial for studying the molecular mechanisms of aneurysm healing after coiling.

Animals↗
PubMed1977

Evaluation of a self-instructional unit for use in educational programs in histologic technique.

A linear programmed instructional booklet was developed and used to evaluate the acceptability of this learning strategy to histologic technique instructors and their students. Comparisons of students' cognitive knowledge of the relevant topics before and after using the booklet indicated that most were achieving the booklet's objectives. The post-test score was not significantly affected either by prior experience with programmed materials or by the way the booklet was used. The verbal attitude responses of the students were encouraging, and most indicated the booklet was an efficient way for them to learn, and it was helpful in clarifying concepts. The verbal attitudes of the instructors were also favorable. The indications were that booklet use shortened subsequent lecture time and that the booklet was most valuable as a supplement to conventional instructional methods.

Achievement↗
PubMed2004

The detection of Helicobacter pylori in paraffin sections using the PCR technique and various primers as compared to histological techniques.

Helicobacter pylori is thought to represent a significant etiopathogenic factor in diseases of the upper gastrointestinal tract. It seems, therefore, important to elaborate effective techniques for its detection. The aim of the present study was to evaluate the effectiveness of Helicobacter pylori detection using the PCR technique on paraffin sections with various pairs of primers and to compare the results with those of a histological appraisal. Material for the studies involved 50 paraffin blocks with gastric mucosa biopsies fixed in 4% buffered formalin. In this material 4 tests were performed with the aim of diagnosing Helicobacter pylori infection: 1) H+E staining, 2) staining by the Giemsa technique, 3) an immunocytochemical technique with antibodies against H. pylori and 4) the PCR technique with various primers. In the present study the most reliable results for H. pylori detection as well as the most pronounced correlation were obtained by using the PCR technique with primers for the ureC gene, immunohistochemistry and staining according to Giemsa. Less compatible results were obtained employing the two PCR techniques which utilise various primers. The experiments confirmed the usefulness of the PCR technique in the detection of Helicobacter pylori in paraffin sections by using a suitable pair of primers, and also indicated that Giemsa staining and immunohistochemistry should be taken into account.

Antigens, Viral↗
PubMedDate not supplied

[Helicobacter pylori detection in children with initially negative Gram, Giemsa and Wharting-Starry methods, using other histologic techniques].

OBJECTIVE: To identify Helicobacter pylori by Gram, Giemsa and Warthing-Starry histological staining methods in biopsies of the digestive tract in children, when Helicobacter pylori identification was negative with hematoxilin and eosin. MATERIAL AND METHODS: We carried out a retrospective, cross-sectional and comparative study of 36 gastric biopsies received in the department of Anatomic-Pathology, in a period often months. All the biopsies were initially stained with routine Hematoxilin and Eosin. Of the 36 biopsies, 24 were negative to Helicobacter pylori. From paraffin blocks of these last biopsies three new histological sections were obtained to dye them with Gram, Giemsa and Warthing-Starry, and two medical pathologists performed the microscopic interpretation of these samples. RESULTS: The search for Helicobacter pylori was carried out in 24 initially negative biopsies, one was positive for Gram (4.16%) and negative for Giemsa and Warthing-Starry and four were both positive for Giemsa and Warthing-Starry (16.66%) and both were also negative for Gram. Only one biopsy was positive for the three methods. The remaining samples were negative for the three stains. CONCLUSION: The Giemsa and/or Warthing-Starry histologic techniques can be a more specific alternative for the determination of Helicobacter pylori in patients with negative digestive tract biopsies with the traditional method of hematoxilin and eosin.

Biopsy↗
PubMed1992

Distribution of goblet cells in the rat nasal septum by use of quantitative histological technique.

In this quantitative, histological study, both goblet cell number and distribution of secretory granules in normal septal mucosa of rats were examined by computer-based color image analysis combined with a new, simple whole-mount method. Our new method has proved to be a very useful and highly accurate means of examination. The count and size of the mucous area of goblet cells decreased toward the antero-posterior direction with the exception of the apical region of the septum. The regional difference characteristic of the goblet cell is noteworthy. The results are assumed to be closely related to both flow direction of mucous blanket and distribution of nasal gland orifices. Goblet cells are assumed to be controlled by some regulatory factor of the secretory system and to play an important role in nasal physiological mechanism.

Animals↗