Search

Objective: The bibliometric perspective examines publications using a quantitative way and statistics to analyze them. The purpose of the current study was to perform a comprehensive overview of the research on the pineal gland through bibliometric methods to determine the trends and rare topics related to the gland. Methods: The Web of Science database was used to identify the publications associated with the gland. The literature review exposed a total of 8719 publications. The identified publications were analyzed using the bibliometric approaches (VOSviewer Version 1.6.13). Results: The first studies on the pineal gland were in the 1970s. The most prolific country is the United States (2451). It was seen that most of the articles were published in Journal of Pineal Research. The majority of publications (97.09%) were written in English. The most prolific author is Reiter, Russel J. Moreover, the most prolific institute is the Centre National De La Recherche Scientifique (France). The most popular keywords in the articles were pineal gland, melatonin, circadian rhythm, rat, retina, photoperiod, circadian, aging, serotonin, oxidative stress, and brain. Conclusion: The results indicated the researchers’ interest in the gland and provided quantitative data about the place of the gland in the scientific area. Studies on this subject have tended to increase in recent years. As far as we know, this research is the first bibliometric study to provide a comprehensive analysis of scientific publications with an emphasis on the pineal gland since 1976. [ABSTRACT FROM AUTHOR]

The ubiquity of circadian rhythms in living organisms has generally been accepted by researchers over the last century. Indeed, morphology and molecular biology of the circadian clock were described during the last fifty years. This main biological clock is located in the suprachiasmatic nucleus of the hypothalamus. This nucleus is connected with the retina by the retinohypothalamic tract. This way, light regulates the functioning of the biological clock and biological rhythms such as the sleep-wake cycle and other cyclic functions by releasing melatonin from the pineal body (PB) into the general circulation. Melatonin reaches the retina via the bloodstream as humoral feedback. More than a hundred years ago a reverse neuronal connection between the central nervous system and the retina was hypothesized. This so-called centrifugal visual or retinopetal system has been explored in detail in birds, but less information is available in mammals. In this work, the morphology and physiology of mammalian centrifugal visual pathways are reviewed. It is generally accepted that the centrifugal (retinopetal) fibers terminate mainly on the amacrine cells of the retina. Histaminergic fibers terminate on dopaminergic amacrine cells. Serotoninergic synapses were identified on ganglion cells. In addition, serotoninergic fibers were also associated with photoreceptor terminals. Luteinizing hormone releasing hormone fibers have been observed in birds, but not in mammalian retinas. In summary, based on the data available in the literature, it seems that the retinopetal system has a mandatory role in lower vertebrates, but a modulatory role in mammals. There is currently no adequate way to eliminate the centrifugal visual system that would better explain its true function.

One hundred and twenty-five years ago there was a lively discussion between Hungarian and Spanish neuroscientists on the nature of neural connections. The question was whether the neurofibrils run from one neuron to the next and connect neurons as a continuous network or the fibrils form an internal skeleton in the neurons and do not leave the cell; however, there is close contact between the neurons. About 50 years later, the invention of the electron microscope solved the problem. Close contacts between individual neurons were identified and named as synapses. In the following years, the need arose to explore distant connections between neuronal structures. Tracing techniques entered neuroscience. There are three major groups of tracers: (A) non-transsynaptic tracers used to find direct connections between two neuronal structures; (B) tracers passing gap junctions; (C) transsynaptic tracers passing synapses that are suitable to explore multineuronal circuits. According to the direction of the transport mechanism, the tracer may be ante- or retrograde. In this review, we focus on the ever-increasing number of fluorescent tracers that we have also used in our studies. The advantage of the use of these molecules is that the fluorescence of the tracer can be seen in histological sections without any other processes. Genes encoding fluorescent molecules can be inserted in various neuropeptide or neurotransmitter expressing transcriptomes. This makes it possible to study the anatomy, development or functional relations of these neuronal networks in transgenic animals. [ABSTRACT FROM AUTHOR]

Circadian rhythmicity is an autonomous period of organ cells’ functioning that is controlled by feedback mechanisms and specific genes. The thyroid gland, as a peripheral organ of the endocrine system, is subordinate to the adenohypophysis and pineal gland. Melatonin, as one of the main mediators of circadian influence, is well known for its antitumor and regulatory effects on a number of tissues, but its relationship with the hormone-producing activity of the thyroid gland has not been sufficiently studied. The purpose of the work was to analyze the current data on circadian regulation of the thyroid gland by examining evidence-based scientific publications from open databases over the past five years. Melatonin-producing pineal cells possess the homeotic genes Otx2 and Crx whose deactivation leads to a significant decrease in melatonin production by the pineal gland. In addition to pineal cells, melatonin can be synthesized by adenohypophysis-independent parafollicular cells. The effect of melatonin on thyrocytes is provided by binding to MT1 receptors and affecting the expression of thyroglobulin, RX-8, and TTF-1 (NKX2-1) genes. Under conditions of short photoperiod, melatonin inhibits the production of thyroid-stimulating hormone (TSH) β, which, in turn, acts on hypothalamic tanycytes by regulating the balance of deiodinase (Dio2/Dio3). This leads to a well-regulated seasonal control of the release of the thyroid hormone triiodothyronine. Conclusions. Circadian regulation of thyrocyte activity occurs under the influence of melatonin, which is secreted by pinealocytes and sometimes by parafollicular cells. TSH is secreted with a certain circadian periodicity under the influence of the activation of chronorhythmic genes. Hormone replacement therapy should be aimed not only at restoring the levels of pituitary hormones, but also at restoring the biological rhythm of TSH secretion. Melatonin affects the circadian work of thyrocytes, which is proven by determining the expression of the chronorhythm genes Bmal-1, Dio2, TTF-1. In thyroid pathology, there is a violation of circadian rhythms, a decrease in melatonin levels, and a decrease in the expression of Clock genes.

The interpretation of 18F-DOPA PET/CT performed for assessing nigrostriatal dysfunction (NSD) is usually based on visual assessment of the uptake in the basal ganglia (VA-BG). In the present study, we evaluate the diagnostic performance of an automated method that assesses BG uptake (AM-BG) and of methods that assess pineal body uptake, and examine whether these methods can enhance the diagnostic performance of VA-BG alone. We retrospectively included 112 scans performed in patients with clinically suspected NSD who also had a subsequent final clinical diagnosis provided by a movement disorder specialist (69 NSD and 43 non-NSD patients). All scans were categorized as positive or negative based on (1) VA-BG, (2) AM-BG, and (3) qualitative and semiquantitative assessment of pineal body uptake. VA-BG, AM-BG, assessment of pineal body 18F-DOPA uptake by VA (uptake > background), by SUVmax (≥0.72), and by pineal to occipital ratio (POR ≥ 1.57) could all significantly differentiate NSD from non-NSD patients (Pv < 0.01 for all five methods). Of these methods, VA-BG provided the highest sensitivity (88.4%) and accuracy (90.2%). Combining VA-BG with AM-BG did not improve diagnostic accuracy. An interpretation algorithm that combines VA-BG with pineal body uptake assessment by POR calculation increased sensitivity to 98.5%, at the expense of decreased specificity. In conclusion, an automated method that assesses 18F-DOPA uptake in the BG and assessment of pineal body 18F-DOPA uptake can significantly separate NSD from non-NSD patients, with apparent inferior diagnostic performance when applied alone compared with VA-BG. When VA-BG categorizes a scan as negative or equivocal, assessment of the 18F-DOPA uptake in the pineal body has the potential to minimize the rate of false negative reports. Further research is essential to validate this approach and to study the pathophysiologic relationship between 18F-DOPA uptake in the pineal body and nigrostriatal dysfunction. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Circadian rhythmicity is an autonomous period of organ cells’ functioning that is controlled by feedback mechanisms and specific genes. The thyroid gland, as a peripheral organ of the endocrine system, is subordinate to the adenohypophysis and pineal gland. Melatonin, as one of the main mediators of circadian influence, is well known for its antitumor and regulatory effects on a number of tissues, but its relationship with the hormone-producing activity of the thyroid gland has not been sufficiently studied. The purpose of the work was to analyze the current data on circadian regulation of the thyroid gland by examining evidence-based scientific publications from open databases over the past five years. Melatonin-producing pineal cells possess the homeotic genes Otx2 and Crx whose deactivation leads to a significant decrease in melatonin production by the pineal gland. In addition to pineal cells, melatonin can be synthesized by adenohypophysis-independent parafollicular cells. The effect of melatonin on thyrocytes is provided by binding to MT1 receptors and affecting the expression of thyroglobulin, RX-8, and TTF-1 (NKX2-1) genes. Under conditions of short photoperiod, melatonin inhibits the production of thyroid-stimulating hormone (TSH) β, which, in turn, acts on hypothalamic tanycytes by regulating the balance of deiodinase (Dio2/Dio3). This leads to a well-regulated seasonal control of the release of the thyroid hormone triiodothyronine. Conclusions. Circadian regulation of thyrocyte activity occurs under the influence of melatonin, which is secreted by pinealocytes and sometimes by parafollicular cells. TSH is secreted with a certain circadian periodicity under the influence of the activation of chronorhythmic genes. Hormone replacement therapy should be aimed not only at restoring the levels of pituitary hormones, but also at restoring the biological rhythm of TSH secretion. Melatonin affects the circadian work of thyrocytes, which is proven by determining the expression of the chronorhythm genes Bmal-1, Dio2, TTF-1. In thyroid pathology, there is a violation of circadian rhythms, a decrease in melatonin levels, and a decrease in the expression of Clock genes. [ABSTRACT FROM AUTHOR]

Some research has shown that melatonin levels increase after meditation practices, but other research has shown that they do not. In our previous functional magnetic resonance imaging study, we found positive activation of the pineal body during Chinese Original Quiet Sitting (COQS). To find other supporting evidence for pineal activation, the aim of this study was to evaluate the effect of COQS on nighttime melatonin levels. Methods: Twenty subjects (11 women and 9 men, aged 29-64 years) who had regularly practiced daily meditation for 5-24 years participated in this study. All subjects served alternately as participants in the mediation and control groups. COQS was adopted in this study. Tests were performed during two nighttime sessions. Saliva was sampled at 0, 10, 20, 30, 45, 60 and 90 minutes after COQS and tested for level of melantonin. Time period effect analysis and mixed effect model analysis were preceded by paired t test analysis. Results: In the meditation group (n = 20), the mean level of melatonin was significantly higher than the baseline level at various times post-meditation (p < 0.001). Within the control group (n = 20), the mean level of melatonin at various times was not significantly different compared with baseline (p>0.05). These results suggested that the melatonin level was statistically elevated in the meditation group and almost unchanged in the control group after nighttime meditation. The urine serotonin levels detected by measuring 5-hydroxy-indole-3-acetic acid levels were also studied, but no detectable difference between the groups was found. Conclusion: Our results support the hypothesis that meditation might elevate the nighttime salivary melatonin levels. It suggests that COQS can be used as a psychophysiological stimulus to increase endogenous secretion of melatonin, which in turn, might contribute to an improved sense of well-being.

The current study was conducted to investigate the relationship between melatonin and chronic anovulation. Adult (3-4 months old) female Wistar rats were submitted to pinealectomy: group I: pinealectomized ovariectomized melatonin-treated (N = 10); group II: pinealectomized ovariectomized placebo-treated (N = 12); group III: pinealectomized light-treated placebo-treated(N = 10) or maintained under continuous light; group IV: maintained under continuous light, ovariectomized melatonin-treated (N = 22); group V: maintained under continuous light, ovariectomized placebo-treated (N = 10); group VI: maintained under continuous light placebo-treated (N = 10). In order to assess ovarian modifications, unilateral ovariectomy was performed during the fourth month in groups I, II, IV, V and the other ovary was removed after 8 months. Ovariectomy was performed in groups III and VI only after eight months. Melatonin (200 µg/100 g body weight) dissolved in 0.02 ml absolute ethanol was injected intramuscularly daily during the last 4 months into groups I and IV. The other groups were treated with placebo (NaCl). The ovarian cysts were analyzed and their area, perimeter and maximum diameter, as well as the thickness of the ovarian capsule were measured. Daily colpocytological smears were performed throughout the study. Persistent estrous condition and ovarian cysts were observed in all groups. In pinealectomized rats the ovarian and vaginal alterations disappeared at the end of the study and in rats maintained under continuous light the vaginal and ovarian polycystic aspect was reversed only in those treated with melatonin. We conclude that melatonin may act on the ovarian response reverting chronic anovulation induced by pinealectomy or continuous light.

Purpose: The purpose was to analyze characteristic magnetic resonance (MR) imaging of pineal region tumors and to explore the value of diffusion-weighted imaging (DWI) and ¹H-MR spectroscopy (¹H-MRS) in differential diagnosis among four common solid diseases: germinoma, teratoma, pineoblastoma, and glioma. Methods: Thirty-three patients with pineal region tumors proven by pathology were prospectively studied. All of them underwent MRI SE-T1WI, FSE-T2WI, fluid-attenuated inversion recovery (FLAIR), and postcontrasted MR scan. Minimum apparent diffusion coefficient (ADC) value, and maximum MRS choline/N-acetyl-aspartate (Cho/NAA) and lipid/creatine (Lip/Cr) metabolic peak-height ratios were quantified within each lesion. Results: Most pineal region diseases have their typical morphology, signal intensity, and enhancement style. ADC values were lower in germinoma [(6.98±0.35)*10-1] and pineoblastoma [(9.14±0.79)*10-4] than in teratoma [(2.80±0.18)*10-3] and pineal glioma [(1.63±0.66)*10-3] (P<.05). Cho/NAA ratios were higher in germinoma (2.09±0.39), pineoblastoma (4.70±0.82), and pineal glioma (3.54±0.38) than in teratoma (1.52±0.91) (P<.05). Lip/Cr ratios were lower in germinoma (2.52±0.41) than in teratoma (8.47±1.16) (P<.05). Conclusions: Changes in morphologic features, signal intensity, and enhancement style are the most helpful variables for the differential diagnosis of pineal region tumors. To some extent, DWI and ¹H-MRS imaging enable distinction among them. [ABSTRACT FROM AUTHOR]

Background/purpose: Some research has shown that melatonin levels increase after meditation practices, but other research has shown that they do not. In our previous functional magnetic resonance imaging study, we found positive activation of the pineal body during Chinese Original Quiet Sitting (COQS). To find other supporting evidence for pineal activation, the aim of this study was to evaluate the effect of COQS on nighttime melatonin levels.Methods: Twenty subjects (11 women and 9 men, aged 29-64 years) who had regularly practiced daily meditation for 5-24 years participated in this study. All subjects served alternately as participants in the mediation and control groups. COQS was adopted in this study. Tests were performed during two nighttime sessions. Saliva was sampled at 0, 10, 20, 30, 45, 60 and 90 minutes after COQS and tested for level of melatonin. Time period effect analysis and mixed effect model analysis were preceded by paired t test analysis.Results: In the meditation group (n = 20), the mean level of melatonin was significantly higher than the baseline level at various times post-meditation (p < 0.001). Within the control group (n = 20), the mean level of melatonin at various times was not significantly different compared with baseline (p>0.05). These results suggested that the melatonin level was statistically elevated in the meditation group and almost unchanged in the control group after nighttime meditation. The urine serotonin levels detected by measuring 5-hydroxy-indole-3-acetic acid levels were also studied, but no detectable difference between the groups was found.Conclusion: Our results support the hypothesis that meditation might elevate the nighttime salivary melatonin levels. It suggests that COQS can be used as a psychophysiological stimulus to increase endogenous secretion of melatonin, which in turn, might contribute to an improved sense of well-being. [ABSTRACT FROM AUTHOR]

The effects of occupational 60 Hz magnetic field and ambient light exposures on the pineal hormone, melatonin, were studied in 142 male electric utility workers in Colorado, 1995–1996. Melatonin was assessed by radioimmunoassay of its metabolite, 6-hydroxymelationin sulfate (6-OHMS), in post-work shift urine samples. Personal magnetic field and light exposures were measured over 3 consecutive days using EMDEX C meters adapted with light sensors. Two independent components of magnetic field exposure, intensity (geometric time weighted average) and temporal stability (standardized rate of change metric or RCMS), were analyzed for their effects on creatinine-adjusted 6-OHMS concentrations (6-OHMS/cr) after adjustment for age, month, and light exposure. Geometric mean magnetic field exposures were not associated with 6-OHMS/cr excretion. Men in the highest quartile of temporally stable magnetic field exposure had lower 6-OHMS/cr concentrations on the second and third days compared with those in the lowest quartile. Light exposure modified the magnetic field effect. A progressive decrease in mean 6-OHMS/cr concentrations in response to temporally stable magnetic fields was observed in subjects with low workplace light exposures (predominantly office workers), whereas those with high ambient light exposure showed negligible magnetic field effects. Melatonin suppression may be useful for understanding human biologic responses to magnetic field exposures. Am J Epidemiol 1999;150:27–36 [ABSTRACT FROM PUBLISHER]

The article offers information on a study which examines season-related changes of the ultrastructure and distribution of serotonin (5-HT) on the pineal body of Laiwu black goats. It notes that their antibodies were investigated by immunohistochemical SABC method and transmission electron microscopy (TEM). It mentions that the area of 5-HT containing cells in winter is the highest, summer is the lowest, while spring and autumn are almost the same.

Aquaporins are selective water channel proteins critical in volume homeostasis. In the CNS AQP4 predominates, localized mainly in the glia limitans, the perivascular endfeet and ependyma. The present immunofluorescent study reveals the distribution of aquaporin-4 in the circumventricular organs in rat and chicken brains. The ventricular ependyma (especially in the third one), the subfornical organ, the area postrema, the rat pineal body (in part), and the vascular organ of lamina terminalis were marked by intense immunopositivity. Several areas, however, proved to be immunonegative: the central canal, the subcommissural organ, the ependymal zone of the median eminence in rat but its whole thickness in chicken, the subtrochlear organ, and the paraventricular organ. The immunostaining of the lateral septal and subseptal organs were similar to their environment. Results on developing rats suggested that the aquaporin-4 immunonegativity is a secondary phenomenon. Surveying other structural and functional features, no clear explanation of the heterogeneous occurrence of aquaporin-4 was found. The absence of aquaporin-4 seems to correlate with some features of the “ependymal organs” (thickened, pseudostratified ependyma, presence of blood–brain barrier) and with the avoidance of GFAP. On the other hand, the organs rich in aquaporin-4 have features of the “hypendymal organs” (glial and vascular plexus but no blood–brain barrier). There are organs, however, which do not fit into either group completely, i.e. the lateral septal and subseptal organs. Presence of tight junctions coincides with the absence of aquaporin-4 in the ependyma of spinal cord, the subcommissural organ and the ependyma of median eminence. [ABSTRACT FROM AUTHOR]

A 12-year-old girl with neurofibromatosis type 1 presented with headache, visual acuity and visual field disturbance. Computed tomography and magnetic resonance imaging revealed an enhanced solid mass involving her right optic nerve and optic chiasm, and a cystic lesion in the pineal region that had resulted in obstructive hydrocephalus. An open biopsy of the right optic nerve tumour was performed, and it was histologically identified as a pilocytic astrocytoma. Local irradiation of 50 Gy to the optic pathway tumour was performed, and the tumour has remained stable for more than 29 months. On the contrary, the pineal cystic mass that was also histologically identified as a pilocytic astrocytoma showed marked enlargement within 5 months after a subtotal resection. Chemotherapy with cisplatin and vincristine was performed after a second surgery, and the pineal tumour has not re-grown in 18 months. To our knowledge, this is the first case report to describe synchronous optic and pineal pilocytic astrocytomas associated with neurofibromatosis type 1. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Pinealectomy frequently produces spinal deformity in some animal models, but the precise biological mechanism of this phenomenon remains obscure. The current study investigated the effects of an autograft pineal body on the development of spinal deformity and serum melatonin (MLT) concentration after pinealectomy in the chicken. Thirty-six chickens (2 days of age) were divided into three equal groups. While the removal of the pineal gland was performed in groups B and C, a pineal body autograft was surgically implanted into the body wall musculature only in the pineal transplantation group (group C). Chickens in which no surgical intervention was performed served as intact controls (group A). Posteroanterior radiographs of the spines of the chickens were taken at the age of 8 weeks. These were used to determine Cobb angles and to measure the rib-vertebra angles (RVA) on the concave and convex sides of the curves, from which data the difference between the convex and concave RVA (the RVAD) was calculated. At the end of the study, serum MLT levels were determined using the enzyme-linked immunosorbent assay method, and histopathological examination of specimens from all the groups was performed. The results were compared using one-way analysis of variance followed by Duncan's test for pairwise comparisons or by the Kruskal-Wallis test followed by the Mann-Whitney U tests for comparisons between two groups. In this study, the serum MLT levels in groups B and C were significantly lower than those in group A (P<0.05). However, scoliosis developed in only 7 of 12 (58%) in group B and 6 of 12 (50%) in group C. The average Cobb angle and RVAD in groups B and C were significantly larger than those found in group A (P=0.000 and P=0.001, respectively). Interestingly, there were no significant differences in either serum MLT levels or development of scoliosis between groups B and C. From the results of the current study, it is evident that the intramuscular pineal gland transplantation following pinealectomy in young Hybro Broiler chickens has no significant effect on the development of spinal deformity and serum MLT level. In the light of this result, the role of MLT in the development of spinal deformity in chickens after pinealectomy remains controversial, and further investigations are warranted. [ABSTRACT FROM AUTHOR]

To characterize the immunohistochemical nature of pineal parenchymal tumors (PPT), we examined nine cases of normal pineal bodies and 23 cases of PPT using several neuronal and glial antibodies and 10 novel monoclonal antibodies raised against human pineal tissue. The PPT were classified into four pineocytoma, five pineal parenchymal tumor of intermediate differentiation (Int-PPT), and 14 pineoblastoma. The pinealocytes, parenchymal cells of the pineal body, were labeled with five neuronal and seven pineal monoclonal (from PP1 to PP7) antibodies in the normal pineal bodies. The subjects ranged from 3 to 85 years old, 12 female and eight male subjects were studied. Antibodies to glial cells PI1, PI2 and PX1, stained interstitial cells of the pineal body. Many of the PPT showed positive immunostaining for pinealocyte-associated antigens and neuronal markers. The intensity of immunostaining showed some association with the degree of differentiation of the tumor, but there was a considerable variety of staining from case to case. The pineocytomas are more immunopositive than are the Int-PPT or pineoblastoma for neuronal and pinealocyte-associated antibodies. In particular the neurofilament protein (NFP)68 kDa, PP1 and PP6 showed significant differences of reactivity between pineocytoma, Int-PPT and pineoblastoma, when compared in groups showing extensive positive staining (positive staining in almost all areas of the tumor). By using three representative antibodies, anti-NFP68kDa, PP1 and PP6, we were able to make a clear distinction between pineoblastoma, Int-PPT and pineocytoma. Glial fibrillary acidic protein (GFAP), PI1 and PI2 antibodies only occasionally showed a small number of positive cells in the tumor, and thus we considered these cells to be non-neoplastic interstitial cells or reactive astrocytes entrapped in the tumor. Our data suggest that the glial differentiation of PPT may occur, but that it seems to be a very rare event. [ABSTRACT FROM AUTHOR]

Various histological types of tumors arise in the pineal region. The most common tumors are pineal parenchymal tumors and germ cell tumors. Pineal parenchymal tumors are divided into pineocytoma, pineal parenchymal tumor with intermediate differentiation and pineoblastoma. Pineocytomas are well-differentiated tumors and retain the morphological and immunohistochemical features of pineal parenchymal cells. Lobular architectures and pineocytomatous rosettes are also typical features. In contrast, pineoblastomas are embryonal tumors resembling primitive neuroectodermal tumors (PNET). However, pineoblastomas are distinct from PNET in other sites due to their exhibiting photosensory differentiation including Flexner–Wintersteiner rosettes and fleurettes. Although pineal cysts are tumor-like lesions, and not true neoplasms, they are occasionally difficult to distinguish from pineocytoma and astrocytoma. From the therapeutic aspect, a precise differential diagnosis is critical. The pineal region is the most common site of the brain in which germ cell tumors occur. Germinoma, teratoma, embryonal carcinoma, yolk sac tumor and choriocarcinoma are encountered, and the latter three types of tumors usually constitute elements of mixed germ cell tumors. The morphological and immunohistochemical features of intracranial germ cell tumors are very similar to those of gonadal germ cell tumors, although there are some differences in germinoma. Pineal germinoma may exhibit carcinomatous differentiation. Other types of tumors are occasionally observed, including fibrillary and pilocytic astrocytoma, glioblastoma, ependymoma, melanoma, meningioma and so on. Metastatic pineal tumors are also rare. The most common site of origin for pineal metastasis is the lung. [ABSTRACT FROM AUTHOR]

A 57-year-old male with pineal ganglioneuroblastoma was reported. The tumor was composed of a predominant ganglioneuromatous component and a small neuroblastic component. Primary ganglioneuroblastoma of the pineal region is extremely rare. To our knowledge, only three cases have been documented. This case may have a good prognosis because there is a predominant ganglioneuromatous component defined by both neurofilament triplet proteins and synaptophysin. The clinical significance of the neuronal differentiation in the present case and pathological considerations are discussed. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Legal Medicine is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Immunocytochemical reaction for demonstration of calbindin D-28K has been performed in superficial pineal bodies of the Mongolian gerbil (Meriones unguiculatus) and the rat. Whereas in the Mongolian gerbil there were no clearly expressed calbindin immunoreactive cells, these were numerous in the rat pineal body. Here the calbindin-positive cells - probably pinealocytes - were disposed along capillaries. In view of the role of calbindin in binding and transporting calcium and regulating its intracellular levels, the absence of this protein in the gerbil pineal body has been interpreted as signifying the inability of pinealocytes to eliminate intracellular calcium with possible consequent formation of acervuli. [ABSTRACT FROM AUTHOR]

Ganglion cell tumours are mostly seen in children and young people, but they are extremely rare, accounting for 0.1-0.5% of all brain tumours. It usually occurs in the floor of the third ventricle and the temporal lobe. Recently we have experienced a pineal gangliocytoma, probably the first ever seen in Japan and the fourth case in the world, and have succeeded in a total removal of it. The case concerns a 51-year-old man who sufferend from intermittent blurred vision and headache of 3 years' duration. CT showed, together with severe hydrocephalus, positive contrast medium enhancement and a somewhat irregular but sharply circumscribed high density lesion suggestive of a meningioma. But the brain scintiscan revealed a badly and irregularly demarcated region of warm activity and having little change with time mainly in the pineal region, which was strongly suspicious of gliomas. Hence this scan was thought to be important in diagnosing this tumour. As an operative procedure, biparieto-occipital craniotomy was successfully performed in the 'sea lion' position to remove the tumour totally. Pathological findings indicated a mixture of dispersion and concentration of giant cells possessing prominent nucleoli, abundant chromatin and a prominent nucleus or several nuclei of varying sizes and process-like cell bodies polygonal or irregular in shape. GFAP stain showing no glial fibres and the tumour was thought to be a gangliocytoma. [ABSTRACT FROM AUTHOR]

SUMMARY Intraventricular neurocytoma is a rare cerebral tumour which is usually associated with a good prognosis. It has imaging features which help differentiate it from other cerebral tumours. We report three cases including the first to originate from the pineal gland. The report emphasizes the radiological appearance and reviews the literature. [ABSTRACT FROM AUTHOR]

Distribution of molluscan cardio-excitatory tetrapeptide Phe-Met-Arg-Phe-NH (FMRFamide) was determined by means of immunohistochemistry in the brain and neurohypophysis of the lamprey, Lampetra japonica. Many FMRFamide-like immunoreactive neurons were found in the periventricular nuclear region and in a region near the mammillary recess. Neurons situated in the former region were larger. The immunoreactive cell groups were shown to be located at sites differing from those of the AF-positive cell groups. The fibers of immunoreactive neurons extended in all directions within the brain and towards the spinal cord, some reaching the third ventricle and capillaries. Thus, FMRFamide-like immunoreactive peptides appear to function as neurotransmitters or neuromodulators and possibly also as neurohormones. FMRFamide-like immunoreactive material was rarely observed in the posterior neurohypophysis (neural lobe), but was noted to be present to a limited extent in the caudal part of the anterior neurohypophysis (median eminence). It would thus follow that FMRFamide-like immunoreactive neurons may not necessarily be related to the hypothalamo-neural lobe system, but may possibly be associated with the hypothalamoadenohypophysial system. The pineal body showed no FMRFamide-like immunoreactivity. [ABSTRACT FROM AUTHOR]

The three-dimensional ultrastructure of the pineal body of the rat is described on the basis of freeze-fractured preparations. The pineal capsule consists of irregular cells with very flat and perforated processes. Through these openings, extremely branched canaliculi, extending to almost every pineal cell, communicate with the tissue compartment outside the organ. The pericapillary spaces contain, in juxtaposition with capillaries of the fenestrated type, nerve fibers as well as a flocculent granular and filamentous material of unknown origin and chemical nature. [ABSTRACT FROM AUTHOR]

A survey has been made of the pineal region of the brain of 11 species of marsupials belonging to 5 families and a species from both families of monotremes. The results show that the pineal body of non-eutherian mammals, although well-defined in all species, has a very varied morphology. Three types of pineal recess occur: (i) a pineal recess in sensu stricto, (ii) an intercommissural pineal recess, and (iii) an infrapineal recess. The existence of nerve fibres which pass through the pineal body and form a spatial link between the habenular and posterior commissures, has been demonstrated in marsupials and monotremes. It is also likely that these animals as well as eutherian mammals possess a nervus conarii. Nerve cells are not a constant feature of the non-eutherian pineal body. The subcommissural organ (SCO) is present in all species. It does not exhibit the same degree of morphological variation as the pineal body. Horizontal sections available for 4 species within 3 families of marsupials show it to be composed of a median portion joined to bilateral protuberances. Large nerve cells occur within the SCO in all marsupial species; they are absent from the monotreme SCO. Tentatively, the relationship of these neurons to the SCO is considered to be merely one of association. The importance of an extended comparative study of this region in non- eutherian mammals in order to add insight into its phylogeny and function is emphasized. [ABSTRACT FROM AUTHOR]

The article focuses on a study on effects of metoclopramide on melatonin and pineal neurochemicals in steers grazed on endophyte infected tall fescue. It mentions paddocks received per either a dopamine antagonist, metoclopramide or sucrose three times weekly. It also mentions plasma MEL analysis and pineal glands were collected at termination.

The article presents the study that investigates the blood supply and blood flow to the skin and the other tissues of sheep used in wool production in Australia. The topics discussed include the positive correlation between blood flow and wool growth in sheep and the use of radioactive microspheres in the quantitative blood flow measurement to the skin and the other tissue of sheep.

Rats were perfused from aorta with Ringer's solution and with Karnovsky's fixative, and injected from the right atrium with Mercox resin. Specimens were properly taken, observed under LM, TEM, SEM, and stereophotographed. Fenestrated endothelial cells of the pineal capillary were observed to contain plenty of microtubules running parallel to the long axis of the vessel. The endothelial basal lamina appeared anchored by microfibrils onto fine collagen fibrils and onto the basal lamina of the perivascular cells. These findings indicate resistance of the capillary endothelium against compression by perivascular hydrostatic pressure, and strongly suggest that the perivascular cerebrospinal fluid is absorbed into the capillary lumen. Resin cast of the pineal venous system looked like a glomerule with two longer collecting veins on the ventral surface and with shorter ones on the dorsal side all emptying into the straight sinus and the confluence of sinuses. Resin cast of the choroid plexus venous system tended to lobulate and looked like a vine with a spiral collecting vein emptying into the great vein. Two veins were found connecting the great vein to the confluence and to the transverse sinuses. These could be effective collaterals in case of occlusion of Galen's vein. [ABSTRACT FROM PUBLISHER]

Copyright of Ricerca in Clinica E in Laboratorio is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although current physiological findings imply that the mammalian pineal organ liberates an antigonadal agent, microscopic examinations of this organ have afforded little information regarding the possible storage and release of such a substance. Since it is known that light deprivation for six weeks results in pineal-induced atrophy of certain reproductive organs in adult golden hamsters, one might expect that any morphological manifestations of this activity in the pineal organ would be enhanced in hamsters which had heen deprived of light for that length of time. A comparison at the ultrastructural level of pineal glands from normal and experimentally blinded hamsters revealed that pineal cells from the blinded animals exhibited a greater number of vesicles and contained complex membranous whorls. The possible significance of the vesicles and lamellar whorls is discussed in terms of similar structures found in other tissues. A feature common to pineal tissue of both the normal and experimental hamsters was the apparent cellular segregation of two morphologically distinct types of mitochondria. Pinealocytes containing small, cristaform mitochondria were designated as P1 cells; those containing larger mitochondria characterized by a dense, plexiform array of cristae were designated as P2 cells. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift Für Zellforschung und Mikroskopische Anatomie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Anatomie und Entwicklungsgeschichte is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Early development of veins and sinuses at and around the posterior cranial fossa seemed not to be shown by photographs except for our recent study (Ann Anat, 2020). Examination of histological sections of 38 fetuses at 10–16 weeks gestational age (GA) demonstrated that: (1) the superior petrosal sinus passed posterosuperiorly through the tentorium cerebelli and, distant and lateral to both the cerebellum and internal ear, drained into the transverse sinus; (2) the superior sagittal sinus was underdeveloped, and the inferior sagittal sinus was not yet evident; (3) the straight sinus (STS) originated from a joining of the bilateral pial veins from the lateral ventricular choroid plexus, passed through the inferoposterior part of the falx cerebri, reached the initial confluens sinuum, and then divided into the bilateral transverse sinuses. The STS origin was immediately behind the pineal body, and near the inferoposterior end of the third ventricle. The falx had a thick attachment to the tentorium below the entire course of the STS and was behind other parts of the brain. Therefore, the development and growth of the posterior dural system seemed to be independent from brain growth, and occurred well before the cerebellum grew to fill the posterior cranial fossa. A basic configuration of intracranial veins and sinuses, including embryonic transient veins (such as the vena capitis prima) seemed to be established by venous return from the choroid plexus and cranial wall, without greatly increasing the abundance of neuronal or glial cells in the brain. [ABSTRACT FROM AUTHOR]