Immunocytochemical localization of aromatase-containing neurons in the rat brain during pre- and postnatal development

This article discusses the existence of both spouse abuse and child abuse within families. Recent research suggests that practitioners have often missed the coexistence of these problems within their caseloads. Practice implications for both domestic violence service providers and child welfare professionals are outlined. Recommendations for changes in assessment procedures, treatment planning, and implementation are made.     

Changes in Thy-1 antigen immunoreactivity in the rat retina during pre- and postnatal development

This paper reports the findings of a survey of a group of general dental practitioners (GDPs) from one region of the United Kingdom. The practitioners were asked to complete a questionnaire investigating their approach to the restoration of root-filled teeth. A high response rate was achieved and the replies indicated that most practitioners restore teeth within 1 month of completing the root filling. Nonprecious cast alloys cores were popular as was amalgam for core build-ups. Most practitioners opted for a post which was two-thirds the length of the root and zinc phosphate was the most popular luting material. Almost one-quarter of respondents believed that a root is strengthened by a post retained restoration and a similar number have never attended a postgraduate meeting on the subject of the restoration of root-filled teeth.     

Distribution of the interstitial cells of Cajal in the human anorectum

The interstitial cells of Cajal are proposed to have a role in the control of gut motility. The aim of this study was to establish the distribution of interstitial cells of Cajal in the wall of the normal human anorectum. Interstitial cells of Cajal express the proto-oncogene c-kit. Interstitial cells of Cajal were identified in the colon by immunohistochemical staining, using a rabbit polyclonal anti-c-kit antibody. Anorectal tissue was obtained at surgical resection for carcinoma of the colorectum. Density of interstitial cells of Cajal was graded. Statistical analysis was performed using chi2 tests. In the longitudinal and circular muscle layers of the rectum interstitial cells of Cajal were seen in the bulk of the muscle layer. In the intermuscular plane interstitial cells of Cajal encased the myenteric plexus. Interstitial cells of Cajal were found at the inner margin of the circular muscle and in association with neural elements of the submuscular plexus. Within the internal anal sphincter interstitial cells of Cajal were infrequently scattered among the muscle fibres. The density of interstitial cells of Cajal in the internal anal sphincter was significantly lower than that observed in the circular muscle layer of the rectum (P = 0.014). In conclusion, interstitial cells of Cajal are evenly distributed in the layers of the muscularis propria of the rectum, but have a lower density in the internal anal sphincter.     

Enteric neuronal plasticity and a reduced number of interstitial cells of Cajal in hypertrophic rat ileum

BACKGROUND: Partial obstruction of the ileum causes a notable hypertrophy of smooth muscle cells and enteric neurones in the proximally located intestine. AIMS: To study the expression of neuromessengers in the hypertrophic ileum of rat as little is known about neuromessenger plasticity under these conditions. To investigate the presence of interstitial cells of Cajal (ICC) in hypertrophic ileum. METHODS: Ileal hypertrophy was induced by circumferential application of a strip of plastic film for 18-24 days. Immunocytochemistry, in situ hybridisation, nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry, and ethidium bromide staining were used to investigate the number of enteric neurones expressing neuropeptides and nitric oxide synthase, and the frequency of ICC. RESULTS: In the hypertrophic ileum several neuronal populations showed changes in their expression of neuromessengers. Myenteric neurones expressing vasoactive intestinal peptide (VIP), pituitary adenylate cyclase activating peptide, and galanin were notably increased in number. In submucous ganglia the number of VIP immunoreactive neurones decreased while those expressing VIP mRNA increased. NADPH diaphorase positive submucous neurones increased dramatically while the number of neuronal type nitric oxide synthase expressing ones was unchanged. The number of ICC decreased notably in hypertrophic ileum. CONCLUSION: Enteric neurones change their levels of expression of neuromessengers in hypertrophic ileum. ICC are also affected. The changes are presumably part of an adaptive response to the increased work load.     

Interstitial cells of Cajal mediate enteric inhibitory neurotransmission in the lower esophageal and pyloric sphincters

BACKGROUND & AIMS: Previous studies have suggested that a specific class of interstitial cells of Cajal (ICC) act as mediators in nitrergic inhibitory neurotransmission. The aim of this investigation was to examine the role of intramuscular ICC (IC-IM) in neurotransmission in the murine lower esophageal (LES) and pyloric sphincters (PS). METHODS: Immunohistochemistry and electrophysiology were used to study the distribution and role of IC-IM. RESULTS: The LES and PS contain spindle-shaped IC-IM, which form close relationships with nitric oxide synthase-containing nerve fibers. The PS contains ICC within the myenteric plexus and c-Kit immunopositive cells along the submucosal surface of the circular muscle. IC-IM were absent in the LES and PS of c-kit (W/Wv) mutant mice. Using these mutants, we tested whether IC-IM mediate neural inputs in the LES and PS. Although the distribution of inhibitory nerves was normal in W/Wv animals, NO-dependent inhibitory neurotransmission was reduced. Hyperpolarizations to sodium nitroprusside were also attenuated in W/Wv animals. CONCLUSIONS: The data suggest that IC-IM play an important role in NO-dependent neurotransmission in the LES and PS. IC-IM may be the effectors that transduce NO signals into hyperpolarizing responses. Loss of IC-IM may interfere with relaxations and normal motility in these sphincters.     

Sodium current expression during postnatal development of rat outer hair cells

Outer hair cells of the cultured organ of Corti from newborn rats (0-11 days after birth) were studied in the whole-cell patch-clamp configuration. A voltage-activated sodium current was detected in 97% (n = 109) of the cells at 0-9 days after birth. The properties of this current were: (1) its activation and inactivation kinetics were fast and voltage-dependent, (2) the voltage at half-maximum activation was -45.0 mV, (3) its steady-state inactivation was temperature-sensitive (the half-inactivating voltage was -92.6 mV at 23 degrees C and -84.8 mV at 37 degrees C), (4) the reversal potential (80 mV) was close to the sodium equilibrium potential and currents could be abolished by the removal of extracellular sodium, and (5) tetrodotoxin blocked the current with a Kd of 474 nmol/l. Current amplitudes were up to 1.7 nA at room temperature. Mean current amplitudes showed a developmental time course with a maximum at postnatal days 3 and 7 for outer hair cells from the basal and apical part of the cochlea, respectively. In current-clamp mode cells had membrane potentials of -59.7 +/- 11.7 mV (n = 9). When cells were hyperpolarized by constant current injection, depolarizing currents were able to trigger action potentials. At 18 days after birth, sodium currents were greatly reduced and barely detectable. The results show that, unlike adult outer hair cells, immature outer hair cells regularly express voltage-gated sodium channels. However, due to mismatching of the sodium current inactivation range and membrane potential in vitro, a physiological function appears questionable.     

Variation in the end products of androgen biosynthesis and metabolism during postnatal differentiation of rat Leydig cells

The amount of testosterone (T) secreted by Leydig cells is determined by a balance between T biosynthetic and metabolizing enzyme activities. It has been established that 5alpha-androstan-3alpha,17beta-diol (3alpha-DIOL) is the predominant androgen secreted by the testes of immature rats during days 20-40 postpartum, whereas T is the major androgen by day 56. However, the underlying changes in T biosynthetic and metabolizing enzymes during Leydig cell development and their magnitudes have remained unclear. The aim of the present study was to define the developmental trends for T biosynthetic and metabolizing enzymes in Leydig cells at three distinct stages of pubertal differentiation: mesenchymal-like progenitors on day 21, immature Leydig cells on day 35, and adult Leydig cells on day 90. Production rates for precursor androgen (androstenedione), T, and 5alpha-reduced androgens [androsterone (AO) and 3alpha-DIOL] were measured in progenitor, immature, and adult Leydig cells in spent medium after 3 h in vitro. Steady state messenger RNA (mRNA) levels and enzyme activities of biosynthetic and metabolizing enzymes were measured in fractions of freshly isolated cells at each of the three stages. Unexpectedly, progenitor cells produced significant amounts of androgen, with basal levels of total androgens (androstenedione, AO, T, and 3alpha-DIOL) 14 times higher than those of T alone. However, compared with immature and adult Leydig cells, the capacity for steroidogenesis was lower in progenitor cells, with a LH-stimulated production rate for total androgens of 84.33 +/- 8.74 ng/10(6) cells x 3 h (mean +/- SE) vs. 330.13 +/- 44.19 in immature Leydig cells and 523.23 +/- 67.29 in adult Leydig cells. The predominant androgen produced by progenitor, immature, and adult Leydig cells differed, with AO being released by progenitor cells (72.08 +/- 9.02% of total androgens), 3alpha-DIOL by immature Leydig cells (73.33 +/- 14.52%), and T by adult Leydig cells (74.38 +/- 14.73%). Further examination indicated that changes in the predominant androgen resulted from differential gene expression of T biosynthetic and metabolizing enzymes. Low levels of type III 17beta-hydroxysteroid dehydrogenase (17betaHSD) mRNA and enzyme activity were present in progenitor cells compared with immature and adult Leydig cells. In contrast, levels of type I 5alpha-reductase (5alphaR) and 3alpha-hydroxysteroid dehydrogenase (3alphaHSD) mRNA and enzyme activities were dramatically lower in adult Leydig cells compared with those in progenitor and immature Leydig cells. Several T biosynthetic enzymes attained equivalent levels in immature and adult Leydig cells, but T was rapidly metabolized in the former to 3alpha-DIOL by high 5alphaR and 3alphaHSD activities, which were greatly reduced in the latter. Therefore, declines in 5alphaR and 3alphaHSD activities are hypothesized to be a major cause of the ascendancy of T as the predominant androgen end product produced by adult Leydig cells. These results indicate that steroidogenic enzyme gene expression is not induced simultaneously, but through sequential changes in T biosynthetic and metabolizing enzyme activities, resulting in different androgen end products being secreted by Leydig cells during pubertal development.     

Expression of the BCL6 gene in the pre- and postnatal mouse

Langerhans cell histiocytosis may be seen with goiter and histiocytic infiltration of the thyroid. We report a 2 1/2-year-old boy who had goiter and primary hypothyroidism develop, later had pulmonary disease, and died of neurologic involvement. Autopsy lesions suggested a transitional dendritic cell precursor of the epidermal Langerhans cell. Of the reported cases of Langerhans cell histiocytosis with goiter in children and adolescents, 82% were male when the relative incidence of Langerhans cell histiocytosis is two males to one female.     

Changes in the distribution of intermediate filaments in rat Sertoli cells during the seminiferous epithelium cycle and postnatal development

BACKGROUND: Intermediate filaments (IFs) are components of the cytoskeleton. In mammalian Sertoli cell, IFs are formed by vimentin. Previous studies have shown some characteristics of its distribution in Sertoli cells, however, very little is known of its distributional changes during the seminiferous epithelium cycle and during postnatal development. METHODS: Immunohistochemical and electron microscopic methods were used to determine the distribution of vimentin-type IFs in rat Sertoli cells during the seminiferous epithelium cycle and postnatal development. RESULTS: The distribution of IFs in adult rat Sertoli cell showed distinct cyclic changes during the seminiferous epithelium cycle. At stages I-VI, bundles of IFs extend from the perinuclear region to the supranuclear and apical regions of the Sertoli cell. These apical extensions became shorter at stage VII, and at stages VIII-X IFs were observed only in the perinuclear region. Short apical extensions reappeared at stages XI-XII; and at stages XIII-XIV, they extended again into the apical region. During this cycle, IFs were always closely associated with the heads of elongate spermatids. IFs were also shown to be in close apposition to some specialized structures on the cell membrane, such as the ectoplasmic specialization between adjacent Sertoli cells. During postnatal (p.n.) development, IFs were mainly observed at the basal nuclear region on p.n. day 7. The IFs in the supranuclear or apical regions first appeared at p.n. day 14 and gradually increased during the development. The perinuclear IFs network was fully established by p.n. day 28 and the adult distribution pattern of the IFs was established by p.n. day 42. CONCLUSIONS: Vimentin-type IFs in rat Sertoli cells are a delicate endocellular network, which is centered in the perinuclear region and extends to the apical region of the cell. During the seminiferous epithelium cycle, the distribution of IFs changes in a stage-dependent manner and is closely related to the location of the heads of elongate spermatids. During postnatal development, IFs gradually increase in numbers and the main distribution area is transferred from the basal nuclear to the perinuclear and supranuclear regions.     

Effect of early postnatal under- and overnutrition on the development of IgA plasma cells in mouse gut

Development of gut IgA plasma cells was studied in early postnatal under- and overnutrition. Female mice were allowed to suckle in litters of 4, 9 or 20 pups to produce a state of obesity (litter of 4) or protein-energy malnutrition (litters of 20). Litters of nine were considered as control groups. Overfeeding during the suckling period did not change the development and the number of IgA plasma cells of the small intestine. By contrast, the weanling protein-energy malnourished mice had shorter intestines, reduced weight of gut mucosal, muscular and serosal layers and reduced length of villi. However, protein-energy malnutrition, when limited to the suckling period, had no marked effect on the development of IgA plasma cells. A diminished number of these cells was observed only when a more severe and prolonged state of malnutrition was induced.     

Adipose tissue development during early postnatal life in ewe-reared lambs

This study examines the precise time course that brown adipose tissue (BAT) takes to adopt the characteristics of white adipose tissue in postnatal lambs. Perirenal adipose tissue was sampled from ewe-reared lambs within 1 h of birth and at 1, 2, 4, 7, 14, 21 and 30 days of age and analysed for the amount of mRNA for uncoupling protein (UCP), the amount and activity of UCP, and protein, mitochondrial protein and lipid content. This was combined with measurements of colonic temperature and jugular venous plasma concentrations of thyroid hormones and insulin-like growth factor-1 (IGF-1). Over the first 4-7 days of age, large quantities of UCP mRNA were associated with a peak in plasma triiodothyronine concentration at 2 days of age followed by a maximal amount and activity of UCP at 4 days and a basal colonic temperature of 39.3 degrees C. Between 7 and 30 days there was a large increase in lipid deposition as the amount and activity of UCP and the amount of UCP mRNA declined to basal values and colonic temperature was maintained at 40 degrees C. A significant positive relationship between perirenal adipose tissue lipid content and plasma IGF-1 concentration was observed throughout the study period. It is concluded that ovine adipose tissue maturation occurs in two distinct phases over the first month of life. The precise time scale of this process could be regulated in part by the lamb's body temperature which determines whether adipose tissue is required for heat production (i.e. BAT) or as an endogenous energy source (i.e. white adipose tissue).     

The role of zinc in pre- and postnatal mammalian thymic immunohistogenesis

Histogenetically, the thymus is the primary lymphopoietic organ and provides an optimal microenvironment for the differentiation of T lymphocytes, independently of the influence of foreign antigens. Lymphocytes with diverse potential are produced in a protective microenvironment optimal for their maturation, whose dual cellular network is provided by endodermally derived RE cells and numerous ectomesenchymal cells derived from the neural crest. The full development of intrathymic hematopoiesis depends upon the successful completion of a series of well coordinated cellular interactions between widely divergent (in terms of origin) cells [epithelium (primitive pharynx); ectomesenchyrne (neural crest); and PHSCs (yolk sac, fetal liver)]. The cells of the thymic epithelial primordium do not proliferate in the absence of "inductive" interactions with the ectomesenchyme. Moreover, the nature of the mesenchyme determines the behavior of the thymic epithelial anlagen. The ectomesenchymal origin of chemotactic stem cell factor secretion, responsible for hemopoietic stem cell immigration, is a distinct possibility. The human thymus is a generalized hematopoietic tissue with between 7 to 9 weeks of ontogenesis. In human and dog fetuses various elements of mammalian hematopoiesis were identified intrathymically: B lymphocytes, plasma cells, erythropoietic and granulocytopoietic (neutrophils and eosinophils) cells, antigen presenting dendritic cells, and mast cells. Our light and ultrastructural (transmission and scanning), as well as immunocytochemical observations have established that during the embryonal and fetal period, the thymus is seeded by pluripotent, yolk sac derived PHSCs characterized by the following immunophenotype CD34+CD43+CD38-Lin-HLA-DR+CD69+. Stem cell c-kit tyrosine kinase (also referred to as mast cell growth factor, stem cell factor, or steel factor) in combination with autocrine and paracrine growth factors and cytokines (IL-3, IL-4, IL-5, IL-6, IL-7, G-CSF, etc.) stimulates myelopoiesis, including erythropoiesis, as well as lymphopoiesis. These hematopoietic growth factors are produced by activated lymphoblastic cells and stromal RE cells under the influence of immunoneuroendocrine regulation, supported by the finding that experimental or spontaneous, in vivo neural crest ablation during early mammalian ontogenesis always results in an abnormal development of the thymus, as well as the heart and great vessels, thyroid, and parathyroid glands.     

Emergence and distribution of intimal smooth muscle cells in the postnatal rat aorta

The distribution of aortic intimal smooth muscle cells in the normal rat during postnatal development was studied by electron microscopy and by staining with fluorescence-labeled phalloidin. The phenotypes of intimal and medial smooth muscle cells were almost identical at first; however, during development, the former remained synthetic, whereas the latter became contractile. Confocal laser scanning microscopy was utilized to observe intimal and medial cells separately. Intimal smooth muscle cells were rarely observed in neonatal rats, but appeared by 10 days of age and increased during postnatal development. A combination of confocal and conventional fluorescent microscopy clearly demonstrated that the intimal smooth muscle cells were preferentially distributed in: (1) the right-lateral and dorsal wall of the upper thoracic aorta, (2) the left-lateral and ventral wall of distal two-thirds of the descending aorta, and (3) the downstream side of branch orifices. Intimal smooth muscle cells in group (1) were oriented randomly, whereas most in group (2) ran longitudinally. Intimal smooth muscle cells at branches in group (3) ran obliquely from the edges at the downstream side in an upstream direction. They tended to accumulate in regions of the aortic wall considered to be under high tensile stress.     

Disturbed pyloric motility in Ws/Ws mutant rats due to deficiency of c-kit-expressing interstitial cells of Cajal

Interstitial cells of Cajal (ICC) are believed to initiate the basic contractile activity of the gastrointestinal tract. Interstitial cells of Cajal express c-kit receptor tyrosine kinase and are deficient in Ws/Ws mutant rats with a small deletion of the c-kit gene. As Ws/Ws rats show remarkable bile reflux to the stomach, the contraction pressure of the pylorus was compared between Ws/Ws and control +/+ rats. The contraction pressure of the pylorus was measured using a microtransducer, which was inserted through a pin-hole in the anterior wall of the stomach under anesthesia. The magnitude of bile reflux was estimated by measuring the content of bile acids in the stomach. The c-kit messenger RNA-expressing cells were detected by in situ hybridization. Frequency and the maximum pressure of the contraction were comparable between Ws/Ws and +/+ rats, but the duration of the contraction was significantly shorter in Ws/Ws rats than in +/+ rats. The number of c-kit messenger RNA-expressing ICC in the pylorus of Ws/Ws rats was 1.7% that of +/+ rats. The bile reflux observed in Ws/Ws rats was attributed to the decrease in the duration of the pyloric contraction, which appeared to result from the deficiency of c-kit messenger RNA-expressing ICC.     

Effect of pre- and postnatal nicotine exposure on vasopressinergic system in rats

Intact mycobacteria and mycobacterial cell wall extracts have been shown to inhibit the growth of human and murine bladder cancer. Their mechanism of action is, however, poorly understood. Mycobacterium phlei mycobacterial cell complex (MCC) is a cell wall preparation that has mycobacterial DNA in the form of short oligonucleotides complexed on the cell wall surface. In this study, we have investigated the possibility that MCC has anti-cancer activity that is mediated by two different mechanisms--a direct effect on cancer cell proliferation and viability and an indirect effect mediated by the production of interleukin 12 (IL-12), a cytokine known to possess anti-cancer activity. We have found that, although MCC is a potent inducer of IL-12 and IL-6 synthesis in monocytes and macrophages either in vitro or in vivo, it is unable to induce the synthesis of either IL-12, IL-6 or granulocyte-macrophage colony-stimulating factor (GM-CSF) by the human transitional bladder cancer cell lines HT-1197 and HT-1376. MCC is not directly cytotoxic towards these cancer cells, but induces apoptosis as determined by nuclear DNA fragmentation and by the release of nuclear mitotic apparatus protein. Mycobacterium phlei DNA associated with MCC is responsible for the induction of apoptosis. Our results indicate that MCC directly effects bladder cancer cells by inhibiting cellular proliferation through the induction of apoptosis, and has the potential for an indirect anti-cancer activity by stimulating cancer-infiltrating monocytes/macrophages to synthesize IL-12.     

Development of the ultrastructural organization of the rat neurohypophysis during postnatal ontogenesis

The development of structural components of the posterior hypopysis lobe of rats, the development of the neurosecretory activity of the hypothalamo-hypophyseal nervous system and the establishment of its function as a single system within the first three weeks after birth (1, 7, 14 and 21 days) as well as embryos of the 20th and 21st days of development were studied electron-microscopically. It has been established that the pituicytes of the posterior lobe of the hypophysis of newborn rats are represented by a single type of cells and are completely differentiated. On the 21st day they are in different morpho-functional states and consist of dark and light cells. By the 14th day of development a considerably increased amount of the neurosecretion is observed. By the 21st day the density of neurosecretion granules per a preparation unit does not change. The basal layer of the capillaries is formed not definitely by the birth time; on the 14th day the organization of the vessel wall is almost similar to that of mature animals. The Herring bodies make their appearance on the 21st day after birth. The hypothalamus and neurohypophysis of rats are functionally active before birth. After birth their neurosecretion activity is well pronounced while the hypothalamo-hypophyseal nervous system is not mature yet. By the time of getting sight this system is almost formed and sufficiently active.     

The diet and gut microflora influence the distribution of enteroendocrine cells in the rat intestine

Several functions of the gut are locally influenced by peptides and biogenic amines released from enteroendocrine cells. The aim of the present study was to assess whether the luminal stimulus of diet or microbial flora or diet-microbial interactions have an influence on the distribution of enteroendocrine cells along the crypt-surface axes of the small and large intestine. The effects of diet and indigenous flora were investigated by comparing the numbers of argyrophil and serotonin immunoreactive cells in the jejunum and colon of germ free and conventional rats fed either a purified diet containing fine ingredients or a commercial diet containing crude fibre of cereal origin. The effect of human flora were analysed in germ-free rats inoculated with human faecal organisms. 1. Feeding the commercial diet reduced the number of argyrophil endocrine cells in the jejunum and serotonin immunoreactive cells in the colon of germ-free animals but increased the serotonin immunoreactive cells in the colon of conventional animals. 2. The rat flora increased the serotonin immunoreactive cells in the colon of animals fed a commercial diet and decreased in those fed a purified diet. 3. Inoculation of human flora increased the numbers of serotonin immunoreactive cells both in the jejunum and colon. The results provide evidence that the dietary changes and diet-microbial interactions can affect the regional number of enteroendocrine cells.