Cell kinetics of normal adult hamster bronchial epithelium in the steady state

To establish the progenitor role of bronchial epithelial cells in the steady state, we undertook a quantitative autoradiographic study in normal hamsters. Groups of 7 hamsters were killed 1 h and 1, 2, 3, 4, 7, and 14 d after an intraperitoneal injection of [3H]thymidine (2 microCi/g body wt). Autoradiograms were prepared from 861 Epon sections, 2 microns thick, of left intrapulmonary hilar bronchi. Epithelial cells were classified into 1 of 7 categories: basal-1 (B1) and basal-2 (B2), depending on nuclear height; secretory cells denoted as S1 with zero to 4 granules, S2 with 5 or more granules with intervening cytoplasm, and S3 with abundant granules completely filling the cytoplasm; ciliated (C); and indeterminate (IN). Mean silver grain counts decreased significantly over time only for B1 cells (P less than 0.05), with a cell cycle time of 20.6 d and a DNA synthetic time of 7.5 h. Labeled cells, 1 h after thymidine injection, comprised 30.5% S1, 27.8% B1, 22.8% B2, 6.8% IN, 6.4% S2, 5.7% C, and 0% S3 cells. Labeling indices of individual cell categories (LIc), at 1 h after labeling, were highest for B1 followed by B2 cells, reflecting their proliferative intensity. Labeling index of all epithelial cells combined did not change with time, indicating that there was no major cell death or label dilution. The LIc decreased significantly over time only for B1 and B2 cells (P less than 0.001 and P less than 0.002, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Seminiferous epithelium damage after short period of busulphan treatment in adult rats and vitamin B12 efficacy in the recovery of spermatogonial germ cells

Several different strategies have been adopted in attempt to recover from chemotherapy‐damaged spermatogenesis that is often seen in oncologic patients. In this study, we have evaluated the impact of short period of exposure to busulphan on the haemogram and seminiferous epithelium of adult rats, focusing on spermatogonial depletion and Sertoli cell (SC) integrity. We then examined whether vitamin B₁₂ supplementation improves the haematological parameters and spermatogonia number. The animals received 10 mg/kg of busulphan (BuG) or busulfan+vitamin B₁₂ (Bu/B₁₂G) on the first and fourth days of treatment. In H.E.‐stained testicular sections, the areas of the seminiferous tubule (ST) and seminiferous epithelium were measured. The number of spermatogonia in H.E‐stained and PCNA‐immunolabelled testicular sections was quantified. The frequency of tubules with abnormal SC nuclei or TUNEL‐positive SC was evaluated. Vimentin immunofluorescence in ST was also evaluated. In BuG and Bu/B₁₂G, the animals showed leukopenia and thrombocytopenia, but the body weight reduced only in BuG. The areas of ST and seminiferous epithelium decreased in Bu/B₁₂G and BuG. In BuG, the number of H.E.‐stained and PCNA‐immunolabelled spermatogonia reduced significantly. The frequency of tubules containing abnormal SC nuclei and TUNEL‐positive SC increased and the vimentin immunoexpression pattern changed. In Bu/B₁₂G, the number of H.E.‐stained or PCNA‐immunolabelled spermatogonia increased fourfold in comparison with BuG. The structural changes in ST after 6 days of busulphan exposure may be associated with the potential effect of this anti‐neoplastic agent on SC. The increased number of spermatogonia in the busulphan‐treated animals receiving vitamin B₁₂ indicates that this vitamin can be an adjuvant therapy to improve the fertility in male cancer patients.     

Hamate-pisiform coalition: morphology, clinical significance, and a simplified classification scheme for carpal coalition

Hamate-pisiform coalition is characterized by the abnormal union of the pisiform bone and hamulus of the hamate. Because most reported cases are isolated, and literature on the subject is sparse, relatively little is known about this condition and its clinical significance. The purpose of this report is to discuss the occurrence, morphology, and frequency of hamate-pisiform coalition identified in a skeletal sample of native South Africans, and to conduct a metaanalysis of all known cases in order to clarify the sex distribution, laterality, form, and clinical significance of this condition. Five new cases (three male, two female) of hamate-pisiform coalition were identified in 527 native South Africans. Results indicate that hamate-pisiform coalition is infrequent (0.76%) but may be more likely encountered in individuals of African ancestry. Morphologically, non-osseous examples ranged in appearance from minor expressions involving pitting of an expanded hamulus base, to a variably pitted articulation between an elongated pisiform and hamulus. Osseous union between the two bones tends to extend beyond the hamulus base to adjacent areas of the hamate. Cases involving osseous union appear predisposed to fracture while ulnar neuropathy is significantly more frequent in individuals exhibiting non-osseous coalition. As both non-osseous and osseous cases can have clinical significance, awareness of the variable manifestations of this condition is necessary for hand specialists. A simplified classification system is suggested to more consistently characterize carpal coalitions.     

The kinetics and morphology of the rosette-forming cell response in the popliteal lymph nodes of rats

A modified ICA technique was used to study the kinetics and morphology of the RFC response in rat popliteal lymph nodes after an inoculation of SRBC into the hind footpad. The primary response was followed over a 10-day period. RFC were classified as either macrophages, haemocytoblasts, plasmacytes or lymphocytes.RFC present in the popliteal lymph nodes of uninoculated rats were identified as macrophages and lymphocytes. After inoculation the number of RFC rose rapidly to reach a peak at 5–6 days. It was shown that after incubation at 37° certain RFC from inoculated rats had several layers of adherent SRBC and it was suggested that this was an indication of an active secretion of haemagglutinin. 3–4 days after innoculation large mature haemocytoblasts were actively secreting haemagglutinin whilst from the 5th to the 10th day plasmacytes were the RFC involved in the haemagglutinin production. It is suggested that the large haemagglutinin producing haemocytoblasts arise without mitosis via a process of cell transformation and that RF plasmacytes arise via lymphocyte activation into small haemocytoblasts, mitotic division and eventual maturation into immature plasmacytes. RF lymphocytes were thought not to be involved to any extent in haemagglutinin production.     

Heterogeneity in the distribution and morphology of microglia in the normal adult mouse brain

We have examined the distribution of microglia in the normal adult mouse brain using immunocytochemical detection of the macrophage specific plasma membrane glycoprotein F4/80. We were interested to learn whether the distribution of microglia in the adult brain is related to regional variation in the magnitude of cell death during development and resulting monocyte recruitment, or whether the adult distribution is influenced by other local microenvironmental cues. We further investigated the possibility that microglia are sensitive to their microenvironment by studying their morphology in different brain regions. Microglia are present in large numbers in all major divisions of the brain but are not uniformly distributed. There is a more than five-fold variation in the density of immunostained microglial processes between different regions. More microglia are found in gray matter than white. Particularly, densely populated areas include the hippocampus, olfactory telencephalon, basal ganglia and substantia nigra. In comparison, the less densely populated areas include fibre tracts, cerebellum and much of the brainstem. The cerebral cortex, thalamus and hypothalamus have average cell densities. There was no simple relationship between the amount of developmental cell death and the adult distribution of microglia. An estimate of the total number of microglia in the adult mouse brain, 3.5 x 10(6), is comparable to that found in the liver on a weight for weight basis. However, microglia possess up to twice the surface area of membrane of Kupffer cells, the large resident macrophages of the liver. The proportion of cells that were microglia varied from 5% in the cortex and corpus callosum, to 12% in the substantia nigra. Microglia vary in morphology depending on their location. They were broadly classified into three categories. Compact cells are rounded cells, sometimes with one or two short thick limbs, bearing short processes ("bristles"). They resemble Kupffer cells of the liver and are found exclusively in sites lacking a blood-brain barrier. Longitudinally branched cells are found in fibre tracts and possess several long processes which are usually aligned parallel to, or more occasionally perpendicular to, the longitudinal axis of the nerve fibres. Radially branched cells are found throughout the neuropil. They can be extremely elaborate and there is wide variation in the length and complexity of branching of the processes. There was no evidence of monocyte-like cells in the adult CNS. The systematic variation in microglial morphology provides further evidence that these cells are sensitive to their microenvironment.     

Spontaneous regression over time of the germinal epithelium in a Y chromosome-microdeleted patient: Case report

Azoospermia factor (AZF) region microdeletions, which account for about 10-15% of patients with oligoazoospermia, seem to lack a close genotype-testicular phenotype correlation. Although many genetic and non-genetic factors may contribute to this outcome, it was thought that a spontaneous regression of testicular germ cells might also play a relevant role. The opportunity for carrying out two different testicular biopsies one year apart in an AZFc-microdeleted patient enabled corroboration of this possibility. Indeed, the first biopsy showed a spermatocyte maturation arrest with mean Johnsen scores of 4 and 3.9 in the right and left testes respectively. One year later, the right testicular biopsy showed a picture of Sertoli cell-only syndrome in 90% of the tubules examined, and of spermatogonial maturation arrest in the remaining tubules, with a mean Johnsen score of 2.1. The almost complete absence of germinal cells was confirmed by four left testicular sperm aspirations (TESA), conducted at the same time as the biopsy during an intracytoplasmic sperm injection cycle, which showed the almost exclusive presence of Sertoli cells (85% of the whole cell population). No spermatozoa could be retrieved by TESA or testicular biopsy. To our knowledge, this is the first case of a spontaneous regression of the germinal cell epithelium over time in a patient with a Yq microdeletion without the apparent intervention of any cause known to affect the germinal epithelium.     

The afferent connections of the inferior olivary complex in rats. An anterograde study using autoradiographic and axonal degeneration techniques

Autoradiographic and axonal degeneration techniques were employed to determine the distribution patterns of inferior olivary afferents whose origins were determined using the horseradish peroxidase method.⁷⁰ The Fink-Heimer stain for degenerating axons was used following lesions of the cerebral cortex and spinal cord, while brainstem and cerebellar afferents were mapped by tritiated leucine autoradiography.After unilateral lesions of the mid-thoracic spinal cord, degenerating axons were observed within the subnuclei a and b of the caudolateral medial accessory olive and in the caudolateral dorsal accessory olive. Degeneration after upper cervical cord lesions extended more rostrally and medially within the same olivary subdivisions.Several nuclei within the caudal brainstem projected to the inferior olivary complex. The dorsal column nuclei distributed fibers primarily contralaterally to the lateral part of the dorsal accessory olive and to the caudolateral part of the medial accessory olive; the spinal trigeminal nucleus projected contralaterally to the rostromedial dorsal accessory olive; the medial and inferior vestibular nuclei projected to the ipsilateral subnuclei b, c, and β of the medial accessory olive and to the contralateral dorsomedial cell column; the nucleus prepositus hypoglossi sent fibers to the subnuclei c and β, the dorsal cap and the ventrolateral outgrowth; the lateral reticular nucleus projected to the subnucleus a of the caudolateral medial accessory olive bilaterally; and the reticular formation distributed fibers to the dorsal accessory olive contralaterally and to the β subnucleus ipsilaterally.Study of inferior olivary complex afferents from the deep cerebellar nuclei showed a projection from the fastigial nucleus to the β subnucleus and the ventrolateral outgrowth. The dentate and interpositus nuclei demonstrated topographic connections from these nuclei to the principal olive and accessory olives, respectively. All cerebellar connections were predominantly contralateral.Analysis of mesencephalic and diencephalic areas also demonstrated several inferior olivary complex afferent systems: the caudal pretectum and the superior colliculus projected to the subnucleus c contralaterally and the dorsal lamella of the principal olive ipsilaterally; the nucleus of the optic tract sent fibers to the dorsal cap; the lateral deep mesencephalic nucleus distributed fibers to the ipsilateral dorsal accessory olive and β subnucleus; the medial terminal nucleus of the accessory optic tract projected ipsilaterally to the ventrolateral outgrowth; and several areas including the medial deep mesencephalic nucleus, periaqueductal gray, the nucleus of Darkschewitsch, the subparafascicular nucleus, the rostral red nucleus and the prerubral field all projected ipsilaterally to the principal olive, rostral medial accessory olive, ventrolateral outgrowth and, to a lesser extent, the caudal medial accessory olive, dorsal cap and β subnucleus.Lesions of the frontal cortex produced axonal degeneration primarily ipsilaterally within many olivary subdivisions, especially the medial dorsal accessory olive and the caudomedial medial accessory olive.Although some notable differences in the distribution and laterality of fibers are described, our findings generally corroborate several earlier reports which used different techniques on a variety of species. Inferior olivary afferents from functionally related areas typically demonstrated similar distribution patterns within the subdivisions of the inferior olivary complex. These patterns suggest a functional localization within the inferior olivary complex which may facilitate an understanding of afferents from areas whose functions are not clearly known.     

An electron microscopic study of esophageal epithelium in the newborn and adult mouse

The stratified squamous epithelium of the esophagus in the newborn and adult mouse was studied by histological, histochemical and electron microscopic methods. In the newborn, the cells located above the basal layer elaborate mucus. The relative abundance of Golgi zones and rough-surfaced endoplasmic reticulum suggests the involvement of these organelles in the production of mucous granules. The membrane of mature mucous granules ruptures and their contents become dispersed in the cytoplasm. Mature mucous granules are not seen in the outermost cells which are about to be exfoliated. The process of exfoliation begins in the upper layer of the epithelium when the contiguous cell membranes separate and wide intercellular spaces are formed. While the cells reach the surface, the intercellular spaces widen, the cells lose contact and are shed. The distal surfaces of the cells in the upper layer are lined by a surface coat which consists of finely branched filaments. The esophageal epithelium of the adult mouse is similar to the epidermis and undergoes complete keratinization. The sequential development of differentiation products, namely the cytoplasmic filaments, membrane-coating granules (MCG) and keratohyalin granules is seen as the cells migrate toward the surface. After their formation, MCG migrate toward the cell surface where they become confluent with the plasma membrane and are secreted into the intercellular space. Keratohyalin granules are also elaborated in large numbers and become dispersed as the cells become cornified. As the horny cells are formed the cell constituents such as the rough-surfaced endoplasmic reticulum, Golgi complex, ribosomes, mitochondria and the nucleus disintegrate. The fully keratinized cell has a thickened envelope and is filled with filaments embedded in an amorphous matrix.     

Unsupervised classification of atrial heartbeats using a prematurity index and wave morphology features

ECG heartbeat type detection and classification are regarded as important procedures since they can significantly help to provide an accurate automated diagnosis. This paper addresses the specific problem of detecting atrial premature beats, that had been demonstrated to be a marker for stroke risk or cardiac arrhythmias. The proposed methodology consists of a stage to estimate characteristics such as morphology of P wave and QRS complex as well as indices of prematurity and a non-supervised stage used by the algorithm J-means to separate heartbeat feature vectors into classes. Partition initialization is carried out by a Max–Min approach. Experimental data set is taken from MIT-BIH arrhythmia database. Results evidence the reliability of the method since achieved sensitivity and specificity are high, 92.9 and 99.6%, respectively, for an average output number of 12 discovered clusters that can be considered as appropriate value to separate heartbeat classes from recordings.     

Histometry of normal thyroid glands in neonatal and adult rats

The present histometric study is on thyroid glands of Wistar rats ranging in age from 0 to 120 days. The mean volume of one lobe of the thyroid in 4-month-old animals was some 22-, 10-, 5-, and 3-fold greater, respectively, than the volumes in the newborn, 5-, 10-, and 30-day-old rats. At 4 months of age the mean length of the lobe was 3 times greater than at birth. The volumetric fractions (Vv) of the different histological components (follicular cells, C-cells, colloid, and interstitial tissue) changed considerably in the course of development. The Vv of follicular cells diminished from 61.4% at birth to 37.2% at 4 months. C-cells increased from 2.9% in the newborn to 4% at 15 days, with no further significant change at 4 months. Colloid and stroma together represented 35.7% at birth, increasing to 58.5% at 120 days. In the course of the first 4 months of life, the absolute volumes occupied by follicular cells, C-cells, colloid, and stroma increased 13.25, 30.75, 38.6, and 33.7 times, respectively; these changes reflect the variations that occur in the volume of the gland and the Vv throughout postnatal development.     

Goblet cells in the normal adult human larynx--studies on morphology, distribution and density

From 12 clinically and macroscopically normal larynges from adult persons all the mucosa was prepared and stained with PAS-alcian blue to study the morphology, distribution, and density of the goblet cells. In each larynx goblet cells were counted in 600 fields of 0.01768 mm2 mucosal surface, distributed on 18, 18 and 24 localities in the subglottis, glottis with the sinus of Morgagni, and supraglottis respectively. The goblet cells form a continuous pattern, comprising the entire subglottis, the anterior commissure, the sinus of Morgagni, the false vocal cords, vestibule of the larynx, and reaching to the cranial part of the laryngeal surface of the epiglottis. Another continuous, but goblet cell-free area extended from a couple of mm posterior to the anterior commissure, posteriorad on the cranial surface of the vocal cords, ary regions, aryepiglottic fold, the edge of the epiglottis, and 4-5 mm of the laryngeal surface of the epiglottic top, epiglottic vallecula, piriform recess, and the postcricoid region. Between the pseudostratified, ciliated columnar epithelium with goblet cells and the goblet cell-free stratified squamous epithelium there is a transitional epithelium in which the goblet cells alter from the 40 micron tall goblet cells characteristic of the respiratory tract epithelium to being quite flattened in order to disappear completely in the stratified squamous epithelium. The goblet cell density is significantly lower in the subglottis, viz. 125 cells per field, than in the glottis with the sinus of Morgagni and supraglottis, where the median density is 166 and 161 cells respectively per field. A possible correlation between the influence of the respiratory air upon the density of goblet cells and the complex anatomy of the larynx is discussed.