Fat necrosis with an associated lymphocytic infiltrate represents a histopathologic clue that distinguishes cellular dermatofibroma from dermatofibrosarcoma protuberans.

BACKGROUND: Cellular dermatofibromas (CDFs) and dermatofibrosarcoma protuberans (DFSP) can be challenging to differentiate from one another. Morphologically, both entities commonly extend into the subcutis, exhibit high cellularity with limited cytologic atypia and have a mixed fascicular-to-storiform growth pattern. We sought to evaluate the significance of fat necrosis with an associated lymphocytic infiltrate as a histopathologic clue for distinguishing CDFs from DFSP. METHODS: We identified cases in our pathology database with a primary diagnosis of CDF or DFSP. Punch or excisional biopsy specimens with extension into the subcutis were selected. Previously biopsied lesions and specimens that did not interact with the subcutis were excluded. Histopathologic features were evaluated in hematoxylin and eosin stained sections. RESULTS: Fat necrosis with lymphocytic infiltrate was present in 20/20 cases of CDF. None of the 20 DFSP cases had fat necrosis with lymphocytic infiltrate although 4/20 had fat necrosis alone. CONCLUSIONS: Fat necrosis with associated lymphocytic response can aid in the distinction between CDF and DFSP.

[Exploring the mysteries of megakaryocytopoiesis and thrombopoiesis through comparative hematology].

In modern hematology, research on hematopoiesis and blood cells in vertebrates, such as birds, reptiles, amphibians, and fish, is lagging. This is because there are many experimental constraints when selecting subjects other than humans and mice as research subjects. Currently, the availability of flow cytometry to count classified nucleated blood cells and utilization of whole genome information have led to novel findings. For example, in case of amphibian hematopoiesis studies, megakaryocytes have been found to be present in African clawed frogs (Xenopus laevis), which do not have platelets but have circulating nucleated thrombocytes. Moreover, we shed light on several mysteries, such as the C-terminal region in human TPO molecules not being found in birds, amphibians, and fish TPO molecules and the functional universalities of mutant CALR-MPL binding and EPO-EphB4 binding, in conjunction with comparative hematology.

Histopathological Analysis of 173 Consecutive Patients with Colorectal Carcinoma: A Pathologist's View.

BACKGROUND Worldwide, colorectal carcinomas are the third most common carcinomas in men and the second most common carcinomas in women. Pathological examination of rectum specimens requires special attention for correctly evaluating many prognostically important factors. In this study, we present pathological results of 173 lower anterior resection (LAR) and abdominoperineal resection (APR) specimens retrospectively evaluated. MATERIAL AND METHODS We included 173 LAR and APR specimens in this study. Patients were evaluated in the Istanbul Ekin Private Pathology Laboratory and underwent surgery at Çanakkale State Hospital, General Surgery Clinic. RESULTS Of the 173 specimens, 15 (8.7%) were APR and 158 (91.3%) were LAR specimens. Ninety-four patients (54.3%) were males and 79 patients (45.7%) were females. The mean age of the patients was 63.5 years (range 26-90 years). In the histopathological examination, malignant neoplasm was detected in 172 of the cases (99.4%) and benign endometriosis was detected in 1 of the cases (0.6%). There were 151 (87.2%), 8 (4.6%), 5 (2.9%), 1 (0.6%), 1 (0.6%), 1 (0.6%), 1 (0.6%), 1 (0.6%), and 4 (2.3%) patients with adenocarcinoma, mucinous adenocarcinoma, intramucosal adenocarcinoma in the setting of a high-grade tubulovillous adenoma, synchronous colon/prostate adenocarcinoma, malignant melanoma, signet ring cell carcinoma, gastrointestinal stromal tumor, endometriosis, and adenocarcinoma diagnosed by the examination of colonoscopic biopsy specimens that showed complete regression with neoadjuvant therapy, respectively. CONCLUSIONS When evaluating specimens from patients with colorectal carcinoma, pathological evaluation, which is one of the most fundamental pillars in managing patients with cancer, must be performed carefully and meticulously. Each pathological parameter should be evaluated carefully and clinicians and pathologists should evaluate these cases together.

Comparative histology of some craniofacial sutures and skull-base synchondroses in non-avian dinosaurs and their extant phylogenetic bracket.

Sutures and synchondroses, the fibrous and cartilaginous articulations found in the skulls of vertebrates, have been studied for many biological applications at the morphological scale. However, little is known about these articulations at the microscopic scale in non-mammalian vertebrates, including extant archosaurs (birds and crocodilians). The major goals of this paper were to: (i) document the microstructure of some sutures and synchondroses through ontogeny in archosaurs; (ii) compare these microstructures with previously published sutural histology (i.e. that of mammals); and (iii) document how these articulations with different morphological degrees of closure (open or obliterated) appear histologically. This was performed with histological analyses of skulls of emus, American alligators, a fossil crocodilian and ornithischian dinosaurs (hadrosaurids, pachycephalosaurids and ceratopsids). Emus and mammals possess a sutural periosteum until sutural fusion, but it disappears rapidly during ontogeny in American alligators. This study identified seven types of sutural mineralized tissues in extant and extinct archosaurs and grouped them into four categories: periosteal tissues; acellular tissues; fibrous tissues; and intratendinous tissues. Due to the presence of a periosteum in their sutures, emus and mammals possess periosteal tissues at their sutural borders. The mineralized sutural tissues of crocodilians and ornithischian dinosaurs are more variable and can also develop via a form of necrosis for acellular tissues and metaplasia for fibrous and intratendinous tissues. It was hypothesized that non-avian dinosaurs, like the American alligator, lacked a sutural periosteum and that their primary mode of ossification involved the direct mineralization of craniofacial sutures (instead of intramembranous ossification found in mammals and birds). However, we keep in mind that a bird-like sutural microstructure might have arisen within non-avian saurichians. While synchondroseal histology is relatively similar in archosaurs and mammals, the microstructural differences between the sutures of these two clades are undeniable. Moreover, the current results suggest that the degree of sutural closure can only accurately be known via microstructural analyses. This study sheds light on the microstructure and growth of archosaurian sutures and synchondroses, and reveals a unique, undocumented histological diversity in non-avian dinosaur skulls.

Of mice and women: a comparative tissue biology perspective of breast stem cells and differentiation.

Tissue based research requires a background in human and veterinary pathology, developmental biology, anatomy, as well as molecular and cellular biology. This type of comparative tissue biology (CTB) expertise is necessary to tackle some of the conceptual challenges in human breast stem cell research. It is our opinion that the scarcity of CTB expertise contributed to some erroneous interpretations in tissue based research, some of which are reviewed here in the context of breast stem cells. In this article we examine the dissimilarities between mouse and human mammary tissue and suggest how these may impact stem cell studies. In addition, we consider the differences between breast ducts vs. lobules and clarify how these affect the interpretation of results in stem cell research. Lastly, we introduce a new elaboration of normal epithelial cell types in human breast and discuss how this provides a clinically useful basis for breast cancer classification.

Age-related changes in the central nervous system in selected domestic mammals and primates.

Aging is a process which operates at many levels of physiological, genetic and molecular organization and leads inevitably to death. Brain macroscopic changes by MRI investigation during aging were observed in humans and dogs but chimpanzees did not display significant changes. This suggestion led to the statement that brain aging is different in various species. Although human brain changes, e.g. ß-amyloid storage, neurofibrillary tangle formation, lipofuscin, are relatively well known, we are still looking for a suitable animal model to study the mechanisms of aging and neurodegenerative diseases. Therefore, this paper presents a comparative analysis of the changes described in the brains of senile dog, horse and gorilla. In addition we present the latest, non-invasive methods that can be applied in the diagnosis of old age in mammals. Our considerations have shown that the best animal model for further studies and observations on aging is the dog.

[Comparative histology of mushroom bodies in carnivorous beetles of the suborder polyphaga (Insecta, Coleoptera)].

Mushroom bodies in beetles of the families Histeridae, Staphylinidae, Cantharidae, Trogossitidae, Peltidae, Cleridae, Malachiidae, and Coccinellidae are shown to be rather poorly developed. The calyx region of the mushroom bodies in these beetles never forms two separate cups, and the peduncular apparatus includes a unified shaft almost over its entire length. Only the pedunculus contains two separate shafts in a few cases. Two proliferative centers consisting of one to three neuroblasts are often found in each Kenyon cell group. The shift from carnivorous to feeding on pollen or leaves, which has taken place in some taxa, does not visibly affect the degree of mushroom body development.

The utility of osteon shape and circularity for differentiating human and non-human Haversian bone.

Distinguishing human from non-human bone fragments is usually accomplished by observation of gross morphology. When macroscopic analysis is insufficient, histological approaches can be applied. Microscopic features, like plexiform bone or osteon banding, are characteristic of non-humans. In the absence of such features, distinguishing Haversian bone as either human or non-human proves problematic. This study proposes a histomorphometric approach for classifying species from Haversian bone. Two variables, osteon area (On.Ar.) and circularity (On.Cr.), are examined. Measurements were collected from three species (deer, dog, human) represented by various skeletal elements; only ribs were available for humans (ribs: deer n = 6, dog n = 6, human n = 26; humeri: deer n = 6, dog n = 6; femora: deer n = 6, dog n = 6). Qualitative analysis comparing human to non-human On.Ar. demonstrated that human ribs have larger mean On.Ar. (0.036 mm(2)) than non-human ribs (deer = 0.017 mm(2) , dog = 0.013 mm(2)). On.Cr. in the ribs showed minor differences between species (deer = 0.877; dog = 0.885; human = 0.898). Results demonstrated no significant difference across long bone quadrants in long bones. Discriminant analyses run on the means for each sample demonstrated overlap in deer and dog samples, clustering the non-human and human groups apart from each other. Mean On.Cr. proved a poor criterion (ribs only: 76.3%, pooled elements: 66.1%), while mean On.Ar. proved useful in identifying human from non-human samples (ribs only: 92.1%, pooled elements: 93.5%). When variables were combined, accuracy increased to 100% correct classification for rib data and 98.4% when considering data from all elements. These results indicate that On.Ar. and On.Cr. are valuable histomorphometric tools for distinguishing human from non-human Haversian bone.

Evaluation of the rabbit nasal cavity in inhalation studies and a comparison with other common laboratory species and man.

The rabbit is occasionally used for inhalation and intranasal safety assessment studies, but there are no detailed descriptions of the anatomy or histology of the rabbit nose. To address this deficit, the nasal cavities of thirty-two control adult rabbits were sectioned and examined to provide mapping of the main epithelial types and histological structures present within the cavity and turbinates. Four levels of the nasal cavity were prepared and examined using anatomic landmarks. Level I was sectioned immediately posterior to the incisors, Level II at the first palatal ridge, Level III immediately anterior to the first upper premolar teeth, and Level IV immediately anterior to the first upper molar. Level I was lined predominantly by squamous epithelium with small amounts of thick transitional epithelium, and examination is recommended only for studies involving test article administration via instillation. Level II was lined primarily with transitional and respiratory epithelia, whereas Levels III and IV were lined with respiratory and olfactory epithelia and often contained nasal-associated lymphoid tissue. The vomeronasal organs were evident only in Level II. The similarities and differences of these features are compared with those of other common laboratory species (rat, mouse, dog, and cynomolgus monkey) and man.

Comparative histology of intradermal implantation of mono and biphasic hyaluronic acid fillers.

BACKGROUND: Hyaluronic acid (HA) gels have been used as filler material in the aesthetic field. Although the native HA molecule is without specificity of species and organs, synthetic cross-linked gels have differences in chemical composition and three-dimensional structure. Different technologies are employed in cross-linking, and the products have varying rheological properties. OBJECTIVE: To determine whether the gels with differing chemical composition have differing histologic behavior when injected into human skin to determine if the histology changes after 14 days of implantation. MATERIALS AND METHODS: Human volunteers consented to having controlled placement of HA intradermally into forearm or buttock skin. The trials were conducted in a single clinic in association with the Hôpitaux Universitaires de Genève, Geneva, Switzerland. The biopsies were taken immediately after implantation of the product and at day 14. Standard paraffin sections were prepared and stained with hematoxylin and eosin and Alcian blue and examined by an independent pathologist. RESULTS: Results show that each type of HA has a predictable histologic behavior in the skin. Biphasic gel has demonstrated deposition in big pools, often deep in the reticular dermis. The pools compress the collagen fibers. The papillary dermis and superficial reticular dermis are free of HA. Monophasic monodensified gels show large pools of hyaluronans throughout all the thickness of the reticular dermis. This material breaks up the collagen fibers of most of the dermal plane. The papillary dermis is free of exogenous hyaluronans. Monophasic polydensified cohesive gel penetrates into the dermis in a diffuse, evenly distributed manner, except in the papillary dermis, which remains free of exogenous material. CONCLUSION: The different types of cross-linked HA have different behaviors in the dermis immediately after their injection. The patterns are consistent between patients and are predictable. These histologic patterns do not change when biopsies are examined at 2 weeks.

Morphometry and comparative histology of sinus and atrioventricular nodes in humans and pigs and their relevance in the prevention of nodal arrhythmias.

The cardiac conduction system is a network structure that allows the initiation and fast propagation of electrical impulses that trigger the electrical depolarization of the myocardial tissue. The purpose of this work is to study the histological and morphometric characteristics of the different components of the sinus and atrioventricular nodes in humans and pigs and their relationship with supraventricular arrhythmias. In this study, we describe the morphometry of the sinus and atrioventricular nodes of 10 adult humans and 10 pig hearts. A computerized morphometric study has been carried out, where we determined the number of cells that compose the nodes as well as different parameters related to their shape and size. The sinus node in human and pig is a compact structure, whose shape is oblong. Their cells (nodal and transitional cells) are pale and located in the center and the periphery, respectively. The atrioventricular node has also a shape oblong. P cells are pale in both species, but in humans, they are smaller than cardiomyocytes. The T cells are small and pale in both species, identified by hematoxylin-eosin and desmin stains. We have observed through a morphometric profile that the structure of sinus and atrioventricular nodes of pigs and humans show few differences. Pigs can be used as models for hemodynamic applications and experimental studies that include atrial electrical conduction and, in this way, prevent the presentation of arrhythmias that can generate sudden deaths in humans and pigs.

The development of archosaurian first-generation teeth in a chicken mutant.

Modern birds do not have teeth. Rather, they develop a specialized keratinized structure, called the rhamphotheca, that covers the mandible, maxillae, and premaxillae. Although recombination studies have shown that the avian epidermis can respond to tooth-inductive cues from mouse or lizard oral mesenchyme and participate in tooth formation, attempts to initiate tooth development de novo in birds have failed. Here, we describe the formation of teeth in the talpid2 chicken mutant, including the developmental processes and early molecular changes associated with the formation of teeth. Additionally, we show recapitulation of the early events seen in talpid2 after in vivo activation of beta-catenin in wild-type embryos. We compare the formation of teeth in the talpid2 mutant with that in the alligator and show the formation of decidedly archosaurian (crocodilian) first-generation teeth in an avian embryo. The formation of teeth in the mutant is coupled with alterations in the specification of the oral/aboral boundary of the jaw. We propose an epigenetic model of the developmental modification of dentition in avian evolution; in this model, changes in the relative position of a lateral signaling center over competent odontogenic mesenchyme led to loss of teeth in avians while maintaining tooth developmental potential.

A symmetrical, extracellular fibril.

Symmetrical, extracellular fibrils, which are related to the "special fibrils" of the dermis described by Palade and Farquhar, have been found along the outer surface of the basement membrane covering the notochord in the tail of Rana catesbeiana (bullfrog) tadpoles. The fibrils are approximately 7,500 A long and occur singly or in clusters. The single fibrils are characterized by a symmetrical transverse band pattern and by attachment at both ends to the basement membrane. The clusters are various complex configurations which seemingly represent symmetrical fibrils in different states of aggregation. Symmetrical fibrils also occur in the skin of the tadpole tail and in the skin of the toad, Bufo marinus. It is proposed that a narrow, symmetrical fibril is the fundamental "special fibril."

Lysosomal nature of juxtaglomerular granules.

Demonstration by a combined histochemical and electron-microscopic technique of the ultrastructure of and acid phosphatase within the juxtaglomerular granules in kidneys of normal man and rat and in those from members of both species with renal Hypertension indicate the identity of Juxtaglomerular granules as lysosomes.

Photoreceptors in primitive chordates: fine structure, hyperpolarizing receptor potentials, and evolution.

Two species of primitive chordates have hyperpolarizing photoreceptor potentials, as vertebrates do. In Salpa the photoreceptive membrane is composed of microvilli, whereas in Amaroucium it is modified from cilia. There appears to be no functional correlation between fine structure of photoreceptive membrane and polarity of response to light.

[Comparative analysis of methods for diagnostics of chlamydial infection in women of reproductive age].

The aim of this study was to compare the effectiveness of three methods of diagnostics of chlamydial infection: polymerase chain reaction (PCR), direct immunofluorescence (DFA) and enzyme immunoassay (EIA). We calculated sensitivity, specificity, positive and negative predictive values for each method of diagnostics. Blood, cervical specimens for detection of Chlamydia trachomatis were obtained from 103 women of reproductive age. The results of investigation show that: 1. PCR, which has high sensitivity (92.1+/-3.4%) and specificity (95.0+/-3.4%), is an effective method of diagnostics of chlamydial infection. 2. While the positive results of PCR in cervical specimens are strong evidence of presence of chlamydial infections, the negative results of PCR in cervical specimens do not prove the absence of chlamydial infection in internal genital organs of women with infertility. For the diagnostics of chlamydial infection in women of reproductive age simultaneous use of two methods of diagnostics is recommended.

Intramandibular glands in different castes of leaf-cutting ant, Atta laevigata (Fr. Smith, 1858) (Formicidae: Attini).

Intramandibular glands have been poorly studied in polymorphic ants, where the differences between castes were unsufficiently scrutinized. Leaf-cutting ants possess one of the most complex systems of communication and labor division, which is polymorphic well as age polyethism, and makes them an ideal model for the study of intramandibular glands. This study has investigated the occurrence of intramandibular glands in female castes and subcastes of Atta laevigata. The mandibles of the queen, medium, and minor workers, and soldiers were submitted to histological, histochemical, ultrastructural, and morphometric analyses. The class-3 gland cells and the epidermal gland with a reservoir were found in all the castes. The queens and soldiers showed a higher number of class-3 gland cells, distributed within the mandible as well as a greater gland size in comparison to the workers. The histochemical tests, periodic acid-Schiff (PAS), mercury-bromophenol, and Nile blue, were similar for the class-3 gland cells and epidermal glands with a reservoir. However, the tests evidenced differences between the castes, with carbohydrates strongly positive in all of them, whereas neutral lipids were found in the queen and soldiers. The protein was weakly positive in the queen, whereas in the soldier, medium, and minor workers these reactions were strongly positive in the intramandibular glands. Our findings in A. laevigata suggest that intramandibular glands are directly involved in labor division and consequently in chemical communication between the castes.

The contributors to Volume 1 (1891) of The Journal of Comparative Neurology: C.L. Herrick, C.H. Turner, H.R. Pemberton, B.G. Wilder, F.W. Langdon, C.J. Herrick, C. von Kupffer, O.S. Strong, T.B. Stowell.

The concept of a truly innovative "neurology" journal germinated in the mind of Clarence Luther Herrick and then flowered, in March of 1891, as the first issue of Volume 1 of The Journal of Comparative Neurology. The other parts appeared in June, October, and December of the same year. The contributors to this volume, and their affiliations, were: C.L. Herrick (University of Cincinnati-UC), C.H. Turner (UC), B.G. Wilder (Cornell), F.W. Langdon (Miami Medical College, Cincinnati), C.J. Herrick (UC) H.R. Pemberton (Princeton), T.B. Stowell (State Normal and Training School, Potsdam), and O.S. Strong of Columbia who translated a large paper by Carl von Kupffer, the famous German anatomist. In 1890-91 some of these scientists (e.g., Wilder, Langdon, Stowell, von Kupffer) were well known and had already made notable contributions in their chosen fields. However, several were students (e.g., Turner, C.J. Herrick, Pemberton, Strong), most of whom would make important contributions in later years. The founder of JCN, Clarence Luther Herrick, by 1891 had an excellent reputation in geology and natural science and had already established a successful scientific journal. Based on the totality of their contributions, the authors of the papers that made up Volume 1 of JCN were a unique group. Textbooks that went through several editions came from Wilder, C.J. Herrick, and Strong; the latter is currently going into its 9th edition. Structures were named in recognition of the original descriptions by von Kupffer and C.L. Herrick, a type of insect behavior recognized Turner's discovery, and after their deaths several had university buildings, one a scientific club, and one a research award, named in their honor. There were also interesting and important links between these nine men. Turner and C.J. Herrick were students of C.L. Herrick, and Stowell served as a member of the Association of American Anatomists nomenclature committee which was chaired by Wilder. C.J. Herrick became a student (for his Ph.D.) of Strong's, and Strong became an associate editor of JCN under C.J. Herrick. Of the nine, two practiced medicine; Langdon in an academic setting, Pemberton in private practice. The lives of the nine scientists whose work made up Volume 1 of JCN are reviewed. Many of these individuals were notable, not only for their work in the first volume of JCN, but for their larger and enduring contributions in the biomedical sciences.

A title oscillation: Journal of Comparative Neurology and Psychology, 1904-1910.

From 1904 through 1910, the Journal of Comparative Neurology became the Journal of Comparative Neurology and Psychology. This article attempts a reconstruction of the events behind this title oscillation from archival sources.

Comparative morphometric studies of benign and malignant intraductal proliferative lesions of the breast by computerized image analysis.

Using computerized image analysis, we newly devised a method for automatic quantitative evaluation of nuclear arrangements in variable proliferative intraductal (cribriform) lesions of the breast, by calculating angles of longest nuclear diameter to a horizon (LNDA). Internuclear correlation in the cribriform lesions was thus examined, comparing 22 benign and 62 malignant cases. In the malignant lesions, nuclear arrangements tended to be multidirectional, probably because of vertical nuclear arrangements toward acinar lumens as reflected by the wide distribution of LNDAs. Conversely, in the benign lesions, groups of nuclei tended to arrange toward one certain direction, forming a complex streaming pattern with the distribution of LNDAs usually producing a distinctive peak. Other conventional nuclear features, such as nuclear area, nuclear perimeter, shortest nuclear diameter (SND), and leading variables were also quantitatively assessed for multivariate analysis. It was noted that nuclear arrangements could represent a favorable discriminator. Linear discriminant function could classify 66 of the total 84 cases (78.6%) as being consistent with the diagnosis of pathologists. We conclude that internuclear arrangement could be a useful discriminating variable in benign and malignant breast lesions for the further development of an automatic analytic system.