Search

BackgroundTibial rotational alignment in total knee arthroplasty (TKA) is generally determined based on intra-articular structure, and can be difficult to ascertain in some cases. The aim of this study was to investigate whether the medial tangent angle of the tibia (MTAT) could be useful in determining the anteroposterior axis of the tibia.MethodsThis study was performed on 103 lower limbs in 53 patients who underwent primary total hip arthroplasty. The selection criteria for our study were based on the assumption that knees in patients undergoing THA exhibit fewer degenerative changes than knees in patients undergoing TKA. Using computed tomography images, the MTAT, comprising the medial tangent of the proximal tibia and the anteroposterior (AP) axis of the tibia, was measured on three horizontal planes: at the distal edge of the tibial tubercle (A), at 5 cm distally (B), and at 10 cm further distally (C). The tibial medial surface was grouped into three classes according to shape: valley type, flat type, and hill type. The percentage at which these shapes were observed in each group was also calculated. Measurement reliability was calculated using the intraclass correlation coefficient.ResultsThe angles were 45.2° (interquartile range: IR 43.0–47.7) at A, 42.7° (IR 38.7–45.9) at B, and 42.4° (IR 38.2–45.9) at C. Intra-rater reliability and inter-rater reliability was 0.982 and 0.974 at A, 0.810 and 0.411 at B, and 0.940 and 0.811 at C, respectively. Regarding the tibial medial surface, the valley type was observed in all cases at A, and the hill type was observed in the highest percentage of cases at B and C.ConclusionsThe MTAT was approximately 45° at level A, and reproducibility was the highest among the three groups. The two points forming the valley on the tibial medial surface were bony ridges. Therefore, the medial tangent of the tibia at level A could be easily determined. Because the distal edge of the tibial tubercle exists at the surgical area and the extra-articular area, it can be a suitable intraoperative, extra-articular landmark in determining the tibial AP axis, even for revision TKA.

We previously reported that synovial mast cells (MCs) from patients with rheumatoid arthritis (RA) produced TNF-α in response to immune complexes via FcγRI and FcγRIIA. However, the specific functions of synovial MCs in RA remain unclear. This study aimed to elucidate those functions. Synovial tissues and fluid were obtained from RA and osteoarthritis (OA) patients undergoing joint replacement surgery. Synovium-derived, cultured MCs were generated by culturing dispersed synovial cells with stem cell factor. We performed microarray-based screening of mRNA and microRNA (miRNA), followed by quantitative RT-PCR-based verification. Synovial MCs from RA patients showed significantly higher prostaglandin systhetase (PTGS)1 and PTGS2 expression compared with OA patients’ MCs, and they produced significantly more prostaglandin D2 (PGD2) following aggregation of FcγRI. PGD2 induced IL-8 production by human group 2 innate lymphoid cells, suggesting that PGD2-producing MCs induce neutrophil recruitment into the synovium of RA patients. PTGS2 mRNA expression in RA patients’ MCs correlated inversely with miRNA-199a-3p expression, which down-regulated PTGS2. RA patients’ synovial fluid contained significantly more PGD2 compared with OA patients’ fluid. Synovial MCs might regulate inflammation in RA through hyper-production of PGD2 following FcRγ aggregation. Our findings indicate functional heterogeneity of human MCs among diseases.

We previously reported that synovial mast cells (MCs) from patients with rheumatoid arthritis (RA) produced TNF-α in response to immune complexes via FcγRI and FcγRIIA. However, the specific functions of synovial MCs in RA remain unclear. This study aimed to elucidate those functions. Synovial tissues and fluid were obtained from RA and osteoarthritis (OA) patients undergoing joint replacement surgery. Synovium-derived, cultured MCs were generated by culturing dispersed synovial cells with stem cell factor. We performed microarray-based screening of mRNA and microRNA (miRNA), followed by quantitative RT-PCR-based verification. Synovial MCs from RA patients showed significantly higher prostaglandin systhetase (PTGS)1 and PTGS2 expression compared with OA patients’ MCs, and they produced significantly more prostaglandin D2 (PGD2) following aggregation of FcγRI. PGD2 induced IL-8 production by human group 2 innate lymphoid cells, suggesting that PGD2-producing MCs induce neutrophil recruitment into the synovium of RA patients. PTGS2 mRNA expression in RA patients’ MCs correlated inversely with miRNA-199a-3p expression, which down-regulated PTGS2. RA patients’ synovial fluid contained significantly more PGD2 compared with OA patients’ fluid. Synovial MCs might regulate inflammation in RA through hyper-production of PGD2 following FcRγ aggregation. Our findings indicate functional heterogeneity of human MCs among diseases.

Background The upregulation of the cyclooxygenase and lipoxygenase pathways of arachidonic acid is thought to be involved in the development of rheumatoid arthritis. Recently, the presence of specialized pro-resolving lipid mediators in synovial tissues from patients with osteoarthritis has been reported. Objective To clarify the quantitative and qualitative changes in lipid mediators in the synovium of severe rheumatoid arthritis patients, we compared the profiles of lipid mediators in synovial fluid obtained from patients with severe rheumatoid arthritis and from those with severe osteoarthritis. Methods We enrolled 18 patients with rheumatoid arthritis and 26 patients with osteoarthritis. All the patients had undergone total knee replacement surgery. Synovial fluid samples had been obtained during the surgery. Lipid profiling in the synovial fluid from these patients was performed using liquid chromatography-tandem mass spectrometry/mass spectrometry. Results Among the 150 oxidized fatty acids examined so far, 119 were substantially detected in synovial fluid from the patients. Not only the concentrations of pro-inflammatory lipid mediators such as prostaglandins and leukotrienes, but also those of specialized pro-resolving lipid mediators such as lipoxins, resolvins, and protectin D1 were significantly higher in synovial fluid obtained from rheumatoid arthritis patients than from synovial fluid obtained from osteoarthritis patients. Conclusion The activation of both inflammation and resolution pathways of lipid mediators might be a fatty acid signature in the synovial fluid of patients with severe rheumatoid arthritis. Inflammatory, anti-inflammatory and pro-resolving mediators in synovial fluid could be good biomarkers for differentiating between severe rheumatoid arthritis and severe osteoarthritis.

Dry skin is a condition characterized by impaired skin barrier function including atopic dermatitis and senile eczemas. Fabric softening chemicals (FSC) smoothens the surface of fabrics and thus decreases friction with the skin. Scientific evaluation of fabric softener on skin dryness is very limited. We evaluated the effectiveness and safety of FSC-treated T-shirts in subjects with dry skin. This is a randomized double-blind control study that included 40 male volunteers with apparent dry skin. Subjects were randomly divided into two groups: 20 men received 28 pieces of FSC-treated T-shirts wearing them for 4 weeks, and another 20 men received non-treated T-shirts. The effect of trial was evaluated by visual grading, subjective symptom, stratum corneum water content (SCWC), transepidermal water loss (TEWL), and dermoscopic skin surface analysis on days 0, 7, 14 and 28. A significant improvement of SCWC was observed in the skin of the shoulder (days 7-28) and lateral abdomen (day 14) wearing the treated T-shirts, but not in the non-treated T-shirts. In a stratified analysis of the low and high SCWC group, significant improvement was identified in the low SCWC groups but not in high SCWC groups. The visual grading of the shoulder improved significantly in the treated T-shirts group. No significant improvement was found in TEWL, dermoscopic analysis and subjective symptom in both groups. No remarkable side-effect was identified throughout this investigation. Addition of a fabric softener during clothes laundering is a potent preventive tool for dry skin.

バックリングモードによるレーザ曲げ加工では, 板がどちら側に曲がるか予測できないことが実用化の大きな障害となっている. 試料の寸法や形状が曲げ特性に与える影響について検討し, 初期弾性変形を与えることにより曲げ方向が制御できることを見出し, レーザ照射条件と曲げ角度の実験式を導いた.

Dry skin is a condition characterized by impaired skin barrier function including atopic dermatitis and senile eczemas. Fabric softening chemicals (FSC) smoothens the surface of fabrics and thus decreases friction with the skin. Scientific evaluation of fabric softener on skin dryness is very limited. We evaluated the effectiveness and safety of FSC-treated T-shirts in subjects with dry skin. This is a randomized double-blind control study that included 40 male volunteers with apparent dry skin. Subjects were randomly divided into two groups: 20 men received 28 pieces of FSC-treated T-shirts wearing them for 4 weeks, and another 20 men received non-treated T-shirts. The effect of trial was evaluated by visual grading, subjective symptom, stratum corneum water content (SCWC), transepidermal water loss (TEWL), and dermoscopic skin surface analysis on days 0, 7, 14 and 28. A significant improvement of SCWC was observed in the skin of the shoulder (days 7-28) and lateral abdomen (day 14) wearing the treated T-shirts, but not in the non-treated T-shirts. In a stratified analysis of the low and high SCWC group, significant improvement was identified in the low SCWC groups but not in high SCWC groups. The visual grading of the shoulder improved significantly in the treated T-shirts group. No significant improvement was found in TEWL, dermoscopic analysis and subjective symptom in both groups. No remarkable side-effect was identified throughout this investigation. Addition of a fabric softener during clothes laundering is a potent preventive tool for dry skin.

Endogenous digitalis-like substance (EDLS) is a newly discovered humoral agent which causes sodium-diuresis. EDLS is well known to have inhibitory activity to Na+,K(+)-ATPase and cross-immunoreactivity to digoxin antibody; however, its precise chemical structure has not yet been determined. We had previously developed a histochemical technique for EDLS, i.e., digoxin-immunohistochemistry, and demonstrated that EDLS was produced in the hypothalamic neurons. In the present study, the distribution of EDLS-containing neurons in the hypothalamus of dog and macaque was investigated using this technique, because anti-EDLS antibody cannot be obtained yet. In both species, EDLS neuronal somata were mainly localized in the paraventricular nucleus and the supraoptic nucleus and its accessory nuclei. A number of somata were also scattered in the other hypothalamic areas. The processes of these neurons ran from the area where the somata were located, through the lateral and basal area of the hypothalamus, to the infundibulum. These nerve fibers with varicosities were associated with the primary capillaries of hypophysial portal veins. A few immunopositive nerve fibers were also seen in the pituitary posterior lobe of both species. Intensive immunoreactivities were observed in the subfornical organ and organum vasculosum laminae terminalis. There were no differences between dog and macaque.

Distribution of gastrin-releasing peptide (GRP)-containing peripheral nerve fibers in the respiratory organs, digestive tracts and hearts of rat, monkey and human was studied with immunohistochemical method. In the trachea, GRP-immunoreactive nerve fibers were observed in the lamina propria and surrounded ducts and acini of tracheal serous glands with a basket-like appearance. In the lung, immunoreactive nerve fibers were scattered in the lamina propria of bronchi and bronchioles, and also the adventitia of veins. In the digestive organs, such as esophagus, duodenum and jejunum, numerous GRP-immunoreactive nerve fibers were distributed in the lamina propria and muscle layer; especially in the former layer where they were seen running up to the apical part of villi. GRP-containing nerve bundles and branched fibers were also observed in the atrial muscle layer. These results gave a morphological basis to future studies of the functional significance of GRP on autonomic mechanisms.

The parietal cortex and dorsal hippocampus of adult rats were unilaterally ablated. One and 3 months after this operation, changes in serotonergic fiber distribution in the forebrain were studied immunohistochemically. At 1 month, increased numbers of serotonergic fibers were seen in the cingulate cortex and the medial and lateral septal nuclei of the lesioned side. This increase continued to 3 months in the ipsilateral cingulate cortex. In the present study, two different processes of serotonergic fiber collateral sprouting were noted. Plastic changes in serotonergic fibers in the ipsilateral septal nuclei and cingulate cortex may be attributable to the collateral sprouting underlying reactive synaptogenesis and the pruning effect, respectively.

1. In situ hybridization histochemistry permits the study of specific mRNAs of neuropeptides, enzymes involved in the synthesis of neurotransmitters, receptors and proteins associated with glial cells in nervous tissue. 2. The central and peripheral nervous systems are composed of heterogeneous elements and specific regulatory mechanisms occur in specific cells. 3. This review will focus on the localization and regulation of different mRNAs in the nervous system from Drosophila to human, as revealed by in situ hybridization histochemistry.

1. The measurement of cellular mRNA content by quantitativein situ hybridization is a valuable approach to the study of gene expression in brain since this tissue exhibits a high degree of phenotypic heterogeneity. 2. The cellular content of vasopressin and oxytocin mRNA in hypothalamo-neurohypophysial system neurons was altered by maintaining rats for 24 hr on 2% sodium chloride water. 3. Statistical and graphical techniques were then used to analyze cell by cell how mRNA levels were altered as a result of osmotic stimulation. We propose that the negative binomial probability distribution is a suitable model to describe how mRNA content varies across a defined cell population. For both measures of oxytocin and vasopressin mRNA levels, maximum-likelihood estimation indicated that this model adequately described empirical findings obtained from rats drinking tap water or salt water. 4. Both graphical and statistical analyses suggested how the defined neural system responds to osmotic stimulation: mRNA content was altered as a multiplicative function of “initial state.” The utility and limitations of the quantitative approach are discussed.

Pieces of fetal midbrain raphe tissue were transplanted into the third ventricle or the ventral hypothalamic region near the suprachiasmatic nucleus (SCN) of adult host rats that had previously been denervated by treatment with 5,6-dihydroxytryptamine. The ability of grafted serotonin neurons to reinnervate the SCN in the host rats was studied by means of immunohistochemistry 1 and 3 months after transplantation. In both the intraventricular and intraparenchymal transplant experiments, reinnervation by outgrowing serotonin fibers was observed in the hypothalamus of host rats at 1 and 3 months after surgery. At both survival periods, there was no abundant arborization of serotonin fibers in the SCN, while the preoptic and periventricular areas of the host rats displayed a pattern of serotonergic innervation resembling that in normal (untreated) rats. It is suggested that within the SCN the regenerating serotonin fibers may be exposed to an inhibitory environment.

Pieces of mesencephalic and medullary raphe tissues were transplanted into the cerebella of 5,6-dihydroxytryptamine-treated adult rats. The extent of axonal outgrowth of serotonergic and dopaminergic neurons in the grafts was immunohistochemically studied. At 3 months after transplantation, numerous dopaminergic neurons with many processes extending within the graft were detected in the mesencephalic raphe graft, but not in the medullary raphe graft. In contrast, both the mesencephalic and medullary raphe grafts contained numerous serotonergic neurons and a dense plexus of their fibers. The outgrowing serotonergic fibers from the mesencephalic raphe graft showed a hyperinnervation pattern in the cerebellar cortex adjacent to the graft. Furthermore, a glomerulus-like accumulation of serotonergic fibers was observed in the granular layer. In the cases of medullary raphe grafts, the relatively abundant outgrowing serotonergic fibers showed a laminar organization in the cerebellar cortex near the graft, which was similar to the normal distributional pattern. These results indicate that serotonergic and dopaminergic neurons located within the mesencephalic raphe graft clearly differed from each other in their ability to extend their processes into the host cerebellum, which provides further evidence for the existence of specific interactions between outgrowing serotonergic fibers and their terminal fields (targets).

Exogenous horseradish peroxidase (HRP, Type VI, Sigma) was applied as a marker for retrograde neuroanatomical tracing in the nigroneostriatal system and the sciatic nerve of adult rats. The retrograde transport and intraneuronal fate of HRP was examined with light and electron microscopy.In the nigroneostriatal system, the labeled neurons containing many brown granules in their perikarya were observed in the ipsilateral substantia nigra 3-4 hours after an injection of HRP, confirming the existence of a nigroneo-striatal pathway. Ultrastructually, these granules appear as multivesicular and lysosomal bodies in the perinuclear region.The labeled nerve cells of the spinal ganglia were also observed within 12 hours after the application of HRP in the sciatic nerve. The HRP positive brown granules had accumulated in the perinuclear region and were rapidly degraded by the lysosomal system disappearing 2 weeks after the injection.In instances of long periods of survival, characteristic lysosomal bodies which included crystals, crystalloid and laminar structures were found.

With a view to improving the immunohistochemical technique for the demonstration of bioactive substances, i.e., neuropeptides and biogenic amines in the mammalian central nervous system, the procedures of immunoperoxidase methods were examined and some modifications for obtaining consistent results were developed.Brains of pharmacologically untreated animals were utilized as the material of the present study. The time through thoracotomy and preperfusion was reduced as much as possible. Perfusion fixation was performed at an increased rate, using a blood pump (hemolizer). The first fixative was a mixture of 4% formaldehyde, 0.2% picric acid, and 0.5% glutaraldehyde in phosphate buffer; the second was 4% formaldehyde and 0.2% picric acid in phosphate buffer acidified to pH6.5 with acetic acid; and the third was buffered formaldehyde solution. The osmotic pressure of all these fixatives was 1550-1650mOsM. Sections 25μm thick were produced on a Microslicer, followed by application of the freezing-thawing technique. The free-floating sections were incubated in a low concentration of antibody solution diluted by 0.5% Triton X-100 in phosphate buffer for a longer period than usual, under cool condition. The reactive substances resulting from the avidinbiotin-peroxidase complex method were enhanced by osmication. With these methods, the serotonin and GRH neurons could be clearly and finely visualized.

The peroxidase-antiperoxidase technique was used to study the ontogenesis of serotonin-containing neurons in fetal, neonatal and adult rats. Serotonin-containing neurons were first detected in a rat embryo of crown-rump length (CRL) 5 mm, bilaterally distributed in the ventral metencephalon near the isthmus rhombencephali. Serotonin fibers were first detected in CRL 6 mm embryos. There was a rapid increase in serotonin-immunoreactive neurons of embryos of 7–8 mm CRL. Serotonin neurons appeared initially as independent, bilateral groups of neurons, but as early as CRL 16 mm, the adult mid-line distribution was present, while the neurons that occurred as single groups in the adult already existed as single groups or at least were only partially connected across the mid-line. A continuous distribution of serotonin neurons was observed in the mesencephalic and pontine reticular formation from CRL 13 mm to the adult stage. It is suggested that the rapid increase in serotonin neurons at 7 and 8 mm CRL is associated with the completion of mitosis which occurs at this time.

Morphological investigation of the endogenous digitals-like substance (EDLS) characterized as a natriuretic humoral agent has not been carried out to date; but EDLS can be detected indirectly by immunohistochemistry using cross-reactivity with digoxin-antibody. In this report, the brain and other organs of the rat and macaque were immunostained using commercially supplied digoxin-specific antibodies. The immunoreactive substances were mainly observed in the neurons of hypothalamic paraventricular and supraoptic nuclei, and varicose fibers in some areas of the hypothalamus and infundibulum. No immunopositive substances were detected in the pituitary anterior lobe, adrenal gland, or kidney of the rat.

The distribution of serotonin-containing neurons in the brain of the dog was studied by use of PAP immunohistochemistry. The lower brain stem was endowed with extensively scattered serotonergic cell bodies, a large portion of which was located in the raphe nuclei. At the same time, prominent distribution of serotonergic neurons in lateral areas outside the raphe nuclei was also demonstrated. Our observations on the brain stem were, in principle, consistent with those on rats, cats and monkeys, with only minor differences.

The oxytocin and vasopressin nerve fibers in the intra- and extrahypothalamic neuronal systems of several mammalian brains are immunohistochemically demonstrated using a modified peroxidase-antiperoxidase technique. The axonal processes of these peptidergic neurons are classified into thick and thin beaded fibers. Thick beaded fibers were preferentially distributed in the hypothalamo-neurohypophysial tract and in some circum-ventricular organs, with termination on the blood vessels. Thin beaded fibers were found in various extrahypothalamic areas and these terminals were in the vicinity of the neuronal somata of such areas. This report suggests that there are at least two different functions concerning neurotransmission in the oxytocin and vasopressin neuronal system.

The lesion of genital Paget's disease usually shows pigmentation, depigmentation, erosion and tumor formation. Skin surrounding the lesion looks normal macroscopically. We call this junction between the resion and surrounding skin the macroscopic margin. The mapping of 3 male cases of genital Paget's disease showed complicated infiltration patterns on the skin surface. We classified these infiltration patterns into 3 types. From a study of preparations according to this classification, we found the recommendable to make a wide excision of the tumor, including the surrounding area reaching more than 3 to 5 cm from the macroscopic margin, since this margin is not reliable in deciding the optimal extent of resection. Moreover, it is recommended that unnecessary resection should be avoided by performing close biopsy preoperatively, especially when there is infiltration around the anus, and that histological examination of the whole margin of the resected tissue be made.

Serotonin-immunoreactive structures in the circumventricular organs (organum vasculosum laminae terminalis, subfornical organ, subcommisural organ and area postrema) of the rat were demonstrated using a modified peroxidase-antiperoxidase immunohistochemical method. Various densities of serotonin fibers were demonstrated in all four circumventricular organs; however, serotonin-positive cells were evident in the area postrema only after nialamide treatment. Serotonergic supraependymal fibers were observed on the surface of the organum vasculosum laminae terminalis and that of the subfornical organ, but not on the subcommissural organ and area postrema. The organ, but not on the subcommissural organ and area postrema. The serotonergic plexus of the basal portion of the subcommisural organ was considered to be continuous with the supraependymal plexus.

The influence of 6-OHDA on the nigro-neostriatal dopaminergic system of the rat from birth to 45 days after birth was investigated with respect to the completion of the BBB to DA. The caudate nucleus and substantia nigra of infant rats were examined by Falck-Hillarp's fluorescence histochemistry and electron microscopy. The most pronounced decrease of DA fluorescence was detected in rats in whom 6-OHDA was repeatedly administered between the end of the first week to the middle of the second week after birth. DA fluorescence also began to decrease gradually in rats after administration of 6-OHDA in the middle of the second week. No further change, however, occurred in DA neurons of rats treated with 6-OHDA at the end of the second post natal week. It was determined that the BBB to DA began to be constituted from the middle of the second week after birth. We also conjectured that 6-OHDA had no potentiality to produce irreversible degeneration of DA neurons in infant animals, since DA fluorescence recovered to the same level as the controls in rats surviving for 4 to 6 weeks after administration of 6-OHDA during the first and second weeks after birth.

A comparative study of serotonergic innervation on motoneurons in the brainstem of various mammals (mouse, rat, guinea pig, dog, cat and monkey) was carried out using a sensitive immunohistochemical method. Except for the extraocular muscle nuclei, the motor nuclei of the cranial nerves received rich inputs from serotonin neurons, in all species examined--rodent, carnivore and primate. The motoneurons of the monkey were innervated by varicose serotonin fibers, in a manner different from that of other species, i.e. their cell bodies and proximal dendrites were tightly encircled by a large number of serotonin-containing varicose fibers. At the ultrastructural level, a predominant population of axosomatic contacts was confirmed in the cranial motor nuclei of the monkey, particularly in the nucleus ambiguus.

The distribution of serotonin neuronal somata in the brain of the rabbit was demonstrated by use of immunoperoxidase technique. The serotonin antibody obtained from a rabbit was applied with the two-step ABC (avidin-biotin-peroxidase complex) method after biotinylation of this antibody. The location, shape, size and immunoreactivity of these somata were clarified in our permanent preparations without non-specific and background staining. These perikarya were distributed in the raphe nuclei, linear nuclei and interpeduncular nucleus, within and around the medial lemniscus, in the mesencephalic periaqueductal grey lateral to the raphe dorsalis, and in the reticular formation of the brain stem. However the so-called "masked indolamine cells" were not observed in the hypothalamus or the area postrema, as our experimental animals were not given any pharmacological pretreatment. These results were essentially similar to those from other mammalian species, especially the rat.

The distributional pattern of serotonin-immunoreactive nerve fibers in the hippocampal formation of six different mammalian species (rat, chipmunk, hamster, cat, dog and monkey) was studied in detail by means of a modified peroxidase-antiperoxidase immunohistochemical method, using a specific serotonin antiserum. Furthermore, the density of varicosities distributed in each layer of the hippocampus was semiquantitatively analyzed. In all species investigated, the routes of serotonin fibers entering the hippocampal formation were found to be almost the same. These fibers were extensively distributed throughout the hippocampal formation, and had a characteristic arrangement corresponding to the laminar structure of this region. A dense innervation by varicose serotonin fibers was found in the stratum lacunosum-moleculare, but a few serotonin fibers were also distributed in the stratum lucidum of the CA2 and CA3 fields. The stratum pyramidale and the granule cell layer of the dentate gyrus contained a small number of serotonin fibers. The concentration and the direction of serotonin fibers were different in each area of each animal. Two peculiar observations should be stressed: (1) in the rat, the strata oriens and radiatum of CA2 and CA3 as well as the stratum lacunosum-moleculare displayed abundant serotonin fibers; (2) in the dog, abundant serotonin fibers were diffusely distributed in the CA1 field except for the stratum pyramidale and the most dense concentratioi > of serotonin fibers was seen in the stratum oriens of CA3.The present study provides a morphological basis for further study of the functional significance of serotonin in the limbic system.

Immunohistochemistry was used to localize brain natriuretic peptide in the porcine spinal cord and to compare it with that of atrial natriuretic peptide, substance P, calcitonin gene-related peptide and [Met]enkephalin. Brain natriuretic peptide-immunoreactive varicose fibers were observed in lamina I and the inner portion of lamina II of the dorsal horn. Semiquantitative analysis showed that the highest density of brain natriuretic peptide-immunoreactive varicosities was in the lumbosacral and coccygeal segments. The distributional pattern of brain natriuretic peptide-immunoreactive nerve fibers in the spinal cord was unique and quite distinct from that of the other neuropeptides studied. These neuroanatomical findings suggest that brain natriuretic peptide may play a role in the regulation of nociceptive processing in the spinal cord, either alone or with bioactive substances.

Liquor contacting peptidergic neurons (LCPNs) in the preoptic nucleus of the Japanese eel (Anguilla japonica), are investigated submacroscopically, light microscopically, electron microscopically (transmission and scanning) and histochemically. LCPNs appear in 8--13 per cent of all neurons constituting the preoptic nucleus and their cytoplasm contains many secretory granules stained by aldehyde-thionin or chrome hematoxylin. LCPNs have an epithelial cell-like polarity and their cytoplasmic organella shift to the supranuclear region. LCPNs are classified into three types (A, B, C) according to the liquor contacting portion of the cell: Granular type A neuron (40--50 x 40--50 microns 2), the cell of which is in contact with the cerebrospinal fluid (CSF), is the most common type and distributed in the ventral portion of the preoptic nucleus; this neuron is not connected with the neighboring ependymal cells by tight junctions. Bipolar type B neuron (60 x 30 micron 2), contacts the CSF with the tip of it cell process and is scattered throughout the preoptic nucleus; the cell is connected with the surrounding ependymal cells by tight junction. Bipolar type C neuron (60 x 30 micron 2) possesses a cell process protruded into the third ventricle and is distributed in the dorsal portion of the preoptic nucleus; this also is connected with the adjacent ependymal cells by tight junction. Regardless of type, all LCPNs exhibit a positive acetylcholinesterase and a negative ATPase reaction. Numerous fluorescent varicosities of monoaminergic nerve terminals are closely associated with the cell bodies of the LCPN. LCPNs are likely regulated by monoaminergic fibers.

The projection from the medial preoptic area to the median eminence of the cat was clarified by electron microscopy. After placing the electrolytic lesion in the preoptic area several kinds of degenerating neuronal processes and terminals were observed in the external layer of the median eminence. The one was dark shrunk terminals containing dense cored vesicles, the other was the dark ones containing myeline figure-like structure. The relationship between catecholamine-containing nerve endings and RH/IH-containing endings in the external layer of the median eminence was discussed.