Histological Methods (histological + methods)

Distribution by Scientific Domains


Selected Abstracts


EVALUATING HISTOLOGICAL METHODS FOR ASSESSING HAIR FIBRE DEGRADATION

ARCHAEOMETRY, Issue 3 2010
A. S. WILSON
The hair shaft has increasing importance in bioarchaeology, since it is now possible to retrieve detailed biomolecular information on recent life history using individual fibres (e.g., on diet, drug use and DNA). Data on hair condition is an important cornerstone to ensuring that reliable information is obtained. The following study defines morphological features of degradative change in human terminal scalp hair using different microscopy techniques. Evidence of degradative change is translated into a ranked histology for assessing hair sample condition. The approach is applied to samples of cut modern scalp hair subjected to degradation under soil burial/simulated grave conditions. [source]


Differentiating Human Bone from Animal Bone: A Review of Histological Methods

JOURNAL OF FORENSIC SCIENCES, Issue 2 2007
Maria L. Hillier M.Sc.
ABSTRACT: This review brings together a complex and extensive literature to address the question of whether it is possible to distinguish human from nonhuman bone using the histological appearance of cortical bone. The mammalian species included are rat, hare, badger, racoon dog, cat, dog, pig, cow, goat, sheep, deer, horse, water buffalo, bear, nonhuman primates, and human and are therefore not exhaustive, but cover those mammals that may contribute to a North American or Eurasian forensic assemblage. The review has demonstrated that differentiation of human from certain nonhuman species is possible, including small mammals exhibiting Haversian bone tissue and large mammals exhibiting plexiform bone tissue. Pig, cow, goat, sheep, horse, and water buffalo exhibit both plexiform and Haversian bone tissue and where only Haversian bone tissue exists in bone fragments, differentiation of these species from humans is not possible. Other primate Haversian bone tissue is also not distinguishable from humans. Where differentiation using Haversian bone tissue is undertaken, both the general microstructural appearance and measurements of histological structures should be applied. Haversian system diameter and Haversian canal diameter are the most optimal and diagnostic measurements to use. Haversian system density may be usefully applied to provide an upper and lower limit for humans. [source]


Photoperiodic differences in a forebrain nucleus involved in vocal plasticity: Enkephalin immunoreactivity reveals volumetric variation in song nucleus lMAN but not NIf in male European starlings (Sturnus vulgaris)

DEVELOPMENTAL NEUROBIOLOGY, Issue 11 2010
Tyler J. Stevenson
Abstract Seasonal variation in the volume of various song control nuclei in many passerine species remains one of the best examples of naturally occurring adult neuroplasticity among vertebrates. The lateral portion of the magnocellular nucleus of the anterior nidopallium (lMAN) is a song nucleus that is important for song learning and seems to be critical for inducing variability in the song structure that is later pruned via a feedback process to produce adult crystallized song. To date, lMAN has not been shown to exhibit seasonal changes in volume, probably because it is difficult to resolve the boundaries of lMAN when employing histological methods based on Nissl staining. Here, lMANcore volumes were examined in intact photostimulated (i.e., breeding), castrated photostimulated and photorefractory (i.e., nonbreeding) male starlings (Sturnus vulgaris) to investigate the degree of seasonal variation in brain morphology. We present data demonstrating that the volumes of the total MAN and lMANcore delineated by enkephalin immunoreactivity are greater in photostimulated male starlings as compared to photorefractory males. Moreover, two other regions associated with the song system that have not been investigated previously in the context of seasonal plasticity namely (i) the medial portion of MAN (mMAN), and (ii) the nucleus interfacialis (NIf) did not display significant volumetric variation. We propose that greater lMANcore volumes are associated with the increase in vocal plasticity that is generally observed prior to production of stereotyped song. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 751,763, 2010 [source]


The impact of joint bleeding and synovitis on physical ability and joint function in a murine model of haemophilic synovitis

HAEMOPHILIA, Issue 1 2008
C. MEJIA-CARVAJAL
Summary., Haemophilia is a congenital disorder that commonly results in musculoskeletal bleeding and orthopaedic complications. After an acute joint haemorrhage, an increase in intra-articular pressure and inflammation cause pain, swelling and limited motion. Blood in the joint space provokes a proliferative disorder known as haemophilic synovitis. Overgrowth of the synovial membrane causes mechanical dysfunction. Eventually, there is destruction of the articular surface and underlying bone. The aim of this project was to test the hypothesis that a minimum number of haemarthroses negatively impacts on joint function and that this would be reflected by decreased physical performance of experimental animals. Mice deficient in factor VIII coagulant activity were trained to ambulate on a rotating rod then injured three times at weekly intervals. Their ability to walk was then compared to a group of uninjured mice. Cohorts of mice were killed after 1, 2 or 3 months and the knee joints examined by gross and histological methods. The results supported the following conclusions: (i) haemophilic mice can be trained to ambulate on a rotating rod; (ii) acute hemarthrosis temporarily impairs their ability to ambulate and (iii) following recovery from acute injury, mice developing synovitis demonstrated inferior physical ability compared to mice not developing synovitis. This is the first description of a quantitative assay to monitor joint function in experimental animals and should be useful to evaluate the efficacy of new therapies developed to prevent and treat bleeding and to test strategies to counter the devastating effects of synovitis. [source]


Application of Histomorphometric Methods to the Study of Bone Repair,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2005
Louis C Gerstenfeld
Abstract ABSTRACT: Standardized methods for the histomorphometric assessment of bone are essential features of most studies of metabolic bone diseases and their treatments. These methodologies were developed to assess coupled remodeling, focusing primarily on osteoblasts and osteoclasts, the anabolic and catabolic rates of these cells, and structural features of mature bone. Research studies on bone healing and the development of new therapeutic approaches for the enhancement of bone repair also require a comprehensive understanding of the basic cellular and tissue level mechanisms that underlie these processes. However, the histological methods developed for metabolic bone disease studies are not completely suitable for studies of bone repair because they are based on assumptions that there is little variation in tissue composition within a sample of bone and not generally designed to quantify other types of tissues, such as cartilage, that contribute to bone healing. These techniques also do not provide tissue-based structural measurements that are relatable to the specific types of biomechanical and radiographic structural assessments that are used to determine rates of bone healing. These deficiencies in current histological approaches therefore point to the need to establish standardized criteria for the histomorphometric assessments that are specifically adapted for the study of bone repair in models of fracture healing and bone regeneration. In this Perspective, we outline what we believe to be the specific structural, tissue. and cellular aspects that need to be addressed to establish these standardized criteria for the histomorphometric assessment of bone repair. We present the specific technical considerations that need to be addressed to appropriately sample repair tissues to obtain statistically meaningful results and suggest specific procedures and definitions of nomenclatures for the application of this technology to bone repair. Finally, we present how aspects of histomorphometric measurements of bone repair can be related to biomechanical and radiographic imaging properties that functionally define rates of bone healing, and thus, how these tools can be used to provide corroborating data. [source]


Molecular staging of gastric cancer

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2008
Yan Jie Zhang
Abstract Gastric cancer has traditionally been staged using purely histological methods, but these methods provide little information about the biology of gastric cancer and have limited predictive power. Recent studies have shown that clinically relevant gastric cancer subtypes have distinct gene expression profiles. This approach, termed molecular staging, can lead to the discovery of novel diagnostic and prognostic biomarkers of gastric cancers. This update reviews advances in molecular staging of gastric cancer and discusses their implications for the prognosis and diagnosis of this complex disease. Technologies used in molecular staging as well as future directions for the optimization of molecular staging of gastric cancer are also discussed. [source]


Effects of delayed stabilization on fracture healing

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 12 2007
Theodore Miclau
Abstract Previous studies have revealed that delayed internal fixation can stimulate fracture callus formation and decrease the rate of nonunion. However, the effect of delayed stabilization on stem cell differentiation is unknown. To address this, we created fractures in mouse tibiae and applied external fixation immediately, at 24, 48, 72, or 96 h after injury. Fracture healing was analyzed at 10 days by histological methods for callus, bone, and cartilage formation, and the mechanical properties of the calluses were assessed at 14 days postinjury by tension testing. The results demonstrate that delaying stabilization for 24,96 h does not significantly affect the volume of the callus tissue (TV) and the new bone (BV) that formed by 10 days, or the mechanical properties of the calluses at 14 days, compared to immediate stabilization. However, delaying stabilization for 24,96 h induces 10,40× more cartilage in the fracture calluses compared with fractures stabilized immediately. These findings suggest that delaying stabilization during the early phase of fracture healing may not significantly stimulate bone repair, but may alter the mode of bone repair by directing formation of more cartilage. Fractures that are not rigidly stabilized form a significantly larger amount of callus tissue and cartilage by 10 days postinjury than fractures stabilized at 24,96 h, indicating that mechanical instability influences chondrocytes beyond the first 96 h of fracture healing. © 2007 Orthopaedic Research Society. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1552,1558, 2007 [source]


Effects of scaling and root planing on the amounts of interleukin-1 and interleukin-1 receptor antagonist and the mRNA expression of interleukin-1, in gingival crevicular fluid and gingival tissues

JOURNAL OF PERIODONTAL RESEARCH, Issue 3 2004
Nobuo Yoshinari
Objective:, The purpose of this study was to evaluate the relationship between the clinical changes after non-surgical periodontal therapy and interleukin 1 (IL-1) in gingival crevicular fluid (GCF) and gingival tissues from patients with chronic periodontitis. Background:, The inflammatory responses mediated by IL-1 play an important role in periodontal tissue destruction. Although numerous studies have attempted to elucidate the dynamic movement involved in chronic periodontitis, the results have often conflicted. Such discrepancies may have been due to the inability to determine clinical disease activity. Methods:, Seven patients with chronic periodontitis were examined. The severity of periodontal inflammation was expressed using clinical parameters before and after a scaling and root planing (SRP) procedure. The amounts and concentrations of IL-1,, IL-1, and IL-1 receptor antagonist in GCF were measured by enzyme-linked immunosorbent assay (ELISA) and IL-1 activity index was calculated. A needle biopsy in matching gingival tissues was also performed before and after the SRP procedure. The localization and mRNA expression of IL-1, were determined using histological methods. Results:, Clinical parameters improved slightly after the SRP procedure. Only the probing pocket depth (PPD) was reduced significantly (p < 0.05). However, the amount of IL-1, in GCF was slightly increased. The localization and mRNA expression of IL-1, could still be observed after the SRP procedure. Therefore, none of the clinical parameters showed a high sensitivity or specificity for evaluating subgingival inflammation. Conclusion:, These observations suggest that IL-1 is effective for evaluating in detail the state of subgingival inflammation. [source]


Validation of macroscopic maturity stages according to microscopic histological examination for European anchovy

MARINE ECOLOGY, Issue 2009
Rosalia Ferreri
Abstract The identification and classification of macroscopic maturity stages plays a key role in the assessment of small pelagic fishery resources. The main scientific international commissions strongly recommend standardizing methodologies across countries and scientists. Unfortunately, there is still a great deal of uncertainty concerning macroscopic identification, which remains to be validated. The current paper analyses reproductive data of European anchovy (Engraulis encrasicolus L. 1758), collected during three summer surveys (2001, 2005 and 2006) in the Strait of Sicily, to evaluate the uncertainty in the macroscopic maturity stage identification and the reliability of the macroscopic adopted scale. On board the survey vessels, the maturity stage of each fish was determined macroscopically by means of an adopted maturity scale subdivided in six stages. Later, at the laboratory, the gonads were prepared for histological examination. The histological slides were analysed, finally assigning the six maturity stages for macroscopic examinations. A correspondence table was obtained with the proportion and number of matches between the two methods. The results highlight critical aspects in the ascription of macroscopic maturity stages, particularly for the present research aim. Different recommendations were evaluated depending on the scope of the study conducted on maturity (e.g. daily egg production, fecundity and maturity ogive computation). The most interesting results concern the misclassification of stage IV and stages III and V (the most abundant), which confirms their macroscopic similarity. Although the results are based on a small number of samples, the advantages and disadvantages of macroscopic and histological methods are discussed with the aim to increase the accuracy of correct identification and to standardize macroscopic maturity ascription criteria. [source]


A simple protocol for paraffin-embedded myelin sheath staining with osmium tetroxide for light microscope observation

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 7 2008
Federica Di Scipio
Abstract Experimental investigation of peripheral nerve fiber regeneration is attracting more and more attention among both basic and clinical researchers. Assessment of myelinated nerve fiber morphology is a pillar of peripheral nerve regeneration research. The gold standard for light microscopic imaging of myelinated nerve fibers is toluidine blue staining of resin-embedded semithin sections. However, many researchers are unaware that the dark staining of myelin sheaths typically produced by this procedure is due to osmium tetroxide postfixation and not due to toluidine blue. In this article, we describe a simple pre-embedding protocol for staining myelin sheaths in paraffin-embedded nerve specimens using osmium tetroxide. The method involves immersing the specimen in 2% osmium tetroxide for 2 h after paraformaldeyde fixation, followed by routine dehydration and paraffin embedding. Sections can then be observed directly under the microscope or counterstained using routine histological methods. Particularly good results were obtained with Masson's trichrome counterstain, which permits the imaging of connective structures in nerves that are not detectable in toluidine blue-stained resin sections. Finally, we describe a simple protocol for osmium etching of sections, which makes further immunohistochemical analysis possible on the same specimens. Taken together, our results suggest that the protocol described in this article is a valid alternative to the conventional resin embedding-based protocol: it is much cheaper, can be adopted by any histological laboratory, and allows immunohistochemical analysis to be conducted. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc. [source]


The pars intercerebralis of the locust brain: A developmental and comparative study

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2002
Peter Ludwig
Abstract The anterior midline of the brain, also known as the pars intercerebralis, contains the largest collection of neurosecretory cells in the central nervous system of the grasshopper. In this study, we use immunocytochemical, intracellular staining, and histological methods to establish the ontogenies of the various cell types in the brain midline, and show how these cells contribute to the pars intercerebralis of the adult brain. We show that the adult pars intercerebralis develops from three distinct embryonic cell groups: (1) the median neurosecretory cells, which derive from a subset of neuroblasts in the protocerebral hemispheres, and which project axons to the corpora cardiaca; (2) the paired primary commissure pioneers, which derive directly from the mesectoderm of the dorsal median domain and whose axons project to the ventral nerve cord via the midline tract; and (3) the six progeny of the median precursor in the dorsal median domain, which share a common axonal projection with the primary commissure pioneers. Since the adult pars intercerebralis is a fusion product of these independent cellular components, it can only be understood in terms of its origins in the embryonic brain. When the expression pattern of the TERM-1 antigen is compared in subsets of median neurosecretory cells in a wide range of insect orders, the results suggests a common organizational Bauplan for the pars intercerebralis. This hypothesis is supported by the identification of putative homologs of the grasshopper primary commissure pioneers in all these insects. Microsc. Res. Tech. 56:174,188, 2002. © 2002 Wiley-Liss, Inc. [source]


"Life history space": A multivariate analysis of life history variation in extant and extinct Malagasy lemurs

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010
Kierstin K. Catlett
Abstract Studies of primate life history variation are constrained by the fact that all large-bodied extant primates are haplorhines. However, large-bodied strepsirrhines recently existed. If we can extract life history information from their skeletons, these species can contribute to our understanding of primate life history variation. This is particularly important in light of new critiques of the classic "fast-slow continuum" as a descriptor of variation in life history profiles across mammals in general. We use established dental histological methods to estimate gestation length and age at weaning for five extinct lemur species. On the basis of these estimates, we reconstruct minimum interbirth intervals and maximum reproductive rates. We utilize principal components analysis to create a multivariate "life history space" that captures the relationships among reproductive parameters and brain and body size in extinct and extant lemurs. Our data show that, whereas large-bodied extinct lemurs can be described as "slow" in some fashion, they also varied greatly in their life history profiles. Those with relatively large brains also weaned their offspring late and had long interbirth intervals. These were not the largest of extinct lemurs. Thus, we distinguish size-related life history variation from variation that linked more strongly to ecological factors. Because all lemur species larger than 10 kg, regardless of life history profile, succumbed to extinction after humans arrived in Madagascar, we argue that large body size increased the probability of extinction independently of reproductive rate. We also provide some evidence that, among lemurs, brain size predicts reproductive rate better than body size. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source]


Morphology of Haemal Nodes in the Roe Deer (Capreolus capreolus)

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2010
Y. Akaydin Bozkurt
With 5 figures Summary The present study was aimed at the determination of the morphology of haemal nodes in the roe deer (Capreolus capreolus). The morphology of haemal nodes located in the abdominal and thoracic cavities of six roe deer (two adult male, two adult female and two foetuses) was studied by gross inspection and histological methods. Oval- and round-shaped haemal nodes with colours varying from pink to dark red were observed particularly between the abdominal aorta and caudal vena cava, and at the beginning of the main branches of the abdominal aorta. These nodes, having connection only with blood vessels, were covered with a thin or thick capsule of connective tissue in the foetus and the adult respectively. Trabeculae were not observed in foetal nodes. In adults, the capsule, trabeculae and, in particular, the sinuses were strongly supported by reticular fibres and cells. The morphology of these nodes displayed similarity to that of other ruminant species. [source]


The ligamentum olecrani of the Elbow Joint in Dogs and Cats

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005
E. Engelke
The olecranon ligament (ligamentum olecrani) is described as an elastic ligament of the elbow joint in carnivores that tenses the caudomedial part of the joint capsule. The aim of the study was to compare the course and the microscopic structure of the ligament in dogs and cats. The elbow regions of 25 dogs and 15 cats were dissected to examine the topography of the ligament in extension and flexion. Furthermore, the olecranon ligaments of five dogs and five cats were studied using routine histological methods. Additional sections were stained with Resorcin,Fuchsin and Orcein to detect elastic fibres. In both species the olecranon ligament originates at the lateral surface of the epicondylus medialis humeri and inserts at the cranial crest of the olecranon extending distally to the roof of the processus anconeus. Tension of the ligament only occurs when the elbow joint is flexed maximally. This tension is increased by a slight supination of the forearm, which takes place automatically in this joint position. In dogs the ligament is long (30,40 mm in medium sized breeds) and relatively slim (approx. 2,4 mm). In cats the ligament is short (10,12 mm) and relatively strong (5,8 mm). The histological examination of the olecranon ligament shows all signs of a tight collagenous ligament with a negligible amount of elastic fibres. The olecranon ligament helps to limit the maximal flexion of the elbow joint. In addition, it controls a slight lateral movement of the processus anconeus during the automatic supination of the antebrachial bones in extreme flexion of the elbow joint. [source]