Kernel Flow: a high channel count scalable time-domain functional near-infrared spectroscopy system.

SIGNIFICANCE: Time-domain functional near-infrared spectroscopy (TD-fNIRS) has been considered as the gold standard of noninvasive optical brain imaging devices. However, due to the high cost, complexity, and large form factor, it has not been as widely adopted as continuous wave NIRS systems. AIM: Kernel Flow is a TD-fNIRS system that has been designed to break through these limitations by maintaining the performance of a research grade TD-fNIRS system while integrating all of the components into a small modular device. APPROACH: The Kernel Flow modules are built around miniaturized laser drivers, custom integrated circuits, and specialized detectors. The modules can be assembled into a system with dense channel coverage over the entire head. RESULTS: We show performance similar to benchtop systems with our miniaturized device as characterized by standardized tissue and optical phantom protocols for TD-fNIRS and human neuroscience results. CONCLUSIONS: The miniaturized design of the Kernel Flow system allows for broader applications of TD-fNIRS.

Stress-reactive response of the gerbil pineal gland: concretion genesis.

The reaction of pinealocytes and glia cells to an acute immobilization stress and their poststress recovery was studied in gerbils. Pinealocytes responded to immobilization with an increased peptidergic activity and formation of new concretions, whereas glia cells with an increased growth of interstitial concretions. The occurrence of degenerating pinealocytes indicated deleterious actions of immobilization stress on functionally stimulated cells. The pyroantimonate method to detect Ca2+ demonstrated enlarged crystalline profiles (Ca2+ crystallization into hydroxyapatite) in functionally stimulated pinealocytes and the accumulation of Ca2+ in the interstitial concretion. The pinealocyte concretions did not show the Ca2+ accumulation. The pineal gland poststress recovery was manifested by a reduced functionally stimulated pinealocyte activity and a protracted increase in glia cell activity. It is suggested that the physiological relevance of the crystallization of Ca2+ into hydroxyapatite is to maintain a noradrenalin-stimulated Ca2+ influx at an optimal level during attentuated pinealocyte turnover. The interstitial concretions may lower the extracellular Ca2+ concentrations and thereby stimulate pinealocytes and restrict an increased Ca2+ influx.

Rat pinealocyte reactive response to a long-term stress inducement.

The pineal gland-reactive response to long-term multifactor stress inducement performed by 18 h immobilization was found in the occurrence of different pinealocyte forms--cells of the basal activity, functionally animated cells and cells assumed to be threatened by an irreversible injury. Functionally animated pinealocytes were recognized as entities of neuroendocrine-like and ependymal-like activities displaying an episode of their initially increased secretory activity determined by Golgi apparatus and succeeded by a period determined by the storage of compounds arising from the cisterns of the granular reticulum. The domination of the pinealocytes with neuroendocrine-like activity was considered to evince a stimulated, peptidergic-mediated pineal gland activity. The adrenocorticotropic hormone-reactive secretion, employed as the evaluation parameter in morphofunctional observations, corroborated the morphologically estimated increased pineal gland activity in long-term stress inducement.

Ultrastructural aspect of myocarditis: its relevance for the diagnosis.

The Dallas consensus was used to reveal active or borderline inflammatory loci by light microscopy (LM). When lymphocyte-cardiocyte interaction was observed by electron microscopy (EM), the deleterious or dormant pattern of inflammatory process was recognized. The first was determined by lymphocytes that adhered to cardiocytes, next to necrotic cardiocytes or admixed with debris. The second was marked by scattered lymphocytes between preserved cardiocytes and the absence of lymphocytes adhered to cardiocytes and necrotic cardiocytes. The deleterious pattern of the inflammatory process (EM) commonly supplemented the active appearance of inflammatory loci (LM). In contrast, the borderline outlook of the LM completed either the deleterious or dormant pattern of the EM. This discrepancy was related to the restricted resolution of LM, which might hide the actual stage of the disease. The diagnosis of myocarditis was founded on mutual LM and EM observations. The active or borderline appearance of LM of the deleterious pattern (EM) was considered indicative for the active stage of myocarditis. The borderline outlook of the LM of the dormant pattern of the EM was admitted to indicate either the healing phase of the disease with lymphocytes still lagging behind, or a latent phase of the ongoing myocarditis, according to the patient's hemodynamic status.

Effect of chronic alcohol feeding on the ultrastructure of rat peripheral blood neutrophils: a morphometric study.

Morphometric methods were used to analyze the ultrastructural characteristics of peripheral blood polymorphonuclear neutrophils (PMN) in 10 rats chronically consuming ethanol and 20 rats fed an isoenergetic standard diet (10 ad libitum and 10 pair fed control rats). Morphometric measurements were made, after a 4-month experimental period, of the following: the profile area of the cell, nucleus and cytoplasm; nucleus to cell profile area; volume density of the nucleus, cytoplasm, mitochondria, Golgi system, endoplasmic reticulum and cytoplasmic granules; number of mitochondria per cell profile; number of cytoplasmic granules per cell profile and per micron2 of cytoplasm, as well as the azurophilic to specific granule ratio and mean diameter of granules. A significant decrease in cell profile area and cytoplasm profile area was shown in ethanol-treated rats. The volume density of mitochondria and endoplasmic reticulum nearly doubled during ethanol abuse. The results also showed that there were highly significant effects of ethanol on the total number of cytoplasmic granules per cell. In addition, changes were observed in mitochondria such as clumping, elongation, swelling and disruption of cristae, as well as changes in the topographic distribution of granules in the cytoplasm such as registration of cytoplasmic areas with numerous granules and areas with a smaller number or without any granules. Some neutrophils of ethanol-treated rats had autophagic vacuoles. The results indicate some ultrastructural abnormalities of PMN in chronic experimental alcoholism that may be related to polymorphonuclear phagocyte dysfunction.

Effects of chronic ethanol administration on the serotonin-producing cells in rat gastric antral and duodenal mucosa.

The present study describes our observations on optical and ultrastructural features of serotonin-containing cells in the rat antral and upper duodenal mucosa, utilizing optic morphometric measurements in a model of experimental chronic alcoholism of rat in which nutrition was well controlled. Male Wistar rats were given ethanol to provide 23 per cent of the total calories, while starch replaced ethanol isocalorically in controls. Twenty-five per cent of the calories were provided by protein in both groups. Blood levels of serotonin were significantly raised after chronic ethanol feeding (0.059 +/- 0.06 vs. 0.159 +/- 0.012 micrograms/ml, p < 0.01). Decrease in the number of immunohistochemically-detectable serotonin-containing cells was found in the pyloric gland mucosal area specimens of the chronically ethanol-treated rats (68.9 +/- 5.2 vs 43.3 +/- 3.0; p < 0.001). The immunohistologically-evaluated number of the same cells in the duodenal mucosa specimens was significantly decreased by alcohol feeding. Although total villi and crypt count per whole circular section, and the number of crypts per villus were not significantly changed either in control animals or in chronically ethanol-fed rats, decreased number of these cells per whole circular section (289 +/- 21.6 vs. 183 +/- 10.5; p < 0.001) per villus (2.52 +/- 0.14 vs. 1.21 +/- 0.10; p < 0.001) and per crypts (0.97 +/- 0.08 vs. 0.79 +/- 0.04; p < 0.05) were reported after alcohol consumption. In both control and experimental rats the cells were predominantly found in the basal half of the antropyloric mucosa. Alcohol did not lead to any changes in normal distribution of the duodenal serotonin-producing cells. The above quantitative changes in serotonin-producing cells were not accompanied by changes in their subcellular appearance in stomach and duodenal mucosa of alcohol-treated rat.

Rat pineal gland suppresses the injection stress-reactive ACTH outflow.

The involvement of the pineal gland in the regulation of the initial ACTH reactive outflow to short-term stress inducement was studied. The stress trial, consisting of the subcutaneous saline injection in the animal hind leg, elicited ACTH release, the peak appearing in the 5th min followed by a rapid downturn to the prestress level in the 15th min. The higher ACTH level in the pinealectomized rats was monitored in the 5th min. The results obtained show the implication of the pineal gland in restricting the magnitude of the initial stress-reactive ACTH outflow.

Morphodynamic response of the rat light pinealocytes to an injection act. Implication of beta-adrenoreceptors.

The implication of beta-adrenoreceptor-mediated noradrenalin action on the reactive morphodynamic response of light pinealocytes (LP) to an injection act, conceived as a short-lasting stress attack, is reported. An injection act, realized by saline-injection, was manifested in the occurrence of clustered "dusk" and "bright" cells--the representative forms of functionally activated LP. The time-related incidence of these cells entities--the appearance of "dusk" and "bright" cells at 5 min, transitory domination of "bright" cells and the nadir of "dusk" cells at 20 min, sporadic recognition of "bright" cells, lack of "dusk" cells at 45 min and the absence of both cell forms at 180 min--displayed that LP-reactive response promptly appeared and rapidly ceased. The injection of beta-adrenoreceptor antagonist, propranolol, did not considerably alter the pattern of LP-reactive response proper for saline-injected rats at 5 min. The constant presence of "dusk" and "bright" cells, structurally changed in all the following time periods under investigation, showed that this drug disordered the course of LP-reactive response to an injection act. On the contrary, LP of resting state was not found to be affected. Estimating functionally, the present results indicate that beta-adrenoreceptor-mediated noradrenalin action is required to promote, maintain and accomplish the LP-reactive response to a short-lasting stress inducement.

[Fatty material in adrenal cortex cells 1 month after contamination with detergent]. / Masne materije u adrenokortikocitima mesec dana nakon prestanka kontaminacije deterdzentima.

The presence of fatty substances: neutral lipids, triglycerides, and phospholipids was detected in the adrenal cortex 30 days after the termination of detergent influence on white laboratory rats. We found that neutral lipids were of increased quantity in the glomerular, fascicular and reticular zone. Triglycerides were present in a greater extent in the entire cortex of animals which were subjected to the influence of detergents. Phospholipids offer an analogue picture: their quantity was increased in all parts of the adrenal cortex in the experimental animals. The described features of the adrenal cortex after detergent influence termination, considering the three groups of fatty substances, undoubtedly indicate the increased activity of the adrenal cortex.

[Morphodynamic response of the pineal gland to an initial stress attack--the effect of morphine]. / Morfodinamicki odgovor pinealne zlezde na trenutni stresogeni atak--dejstvo morfina.

The possible participation of a stimulated ACTH secretion in the promotion of the pineal gland reactive response under conditions of injection stress was studied. Morphine was used as a pharmacological mimicry of the stress-induced ACTH outflow in the post-injection period of 10-45 min. In animals subjected to injection stress (administration of the physiological solution), in the 10-th min. light pinealocytes exhibited a significant rise in the relative volume of the GER field and the Gogli apparatus, as well as bouquets of presecretory or secretory forms of the cell processes and frequent extrusion of lipid droplets. From 20-th min. on, the relative volume of their membranous elaborative compartment gradually decreased, the cell processes were missing and the lipid droplet extrusion was rare. The rich arbourisation of the GER tubules, the active appearance of the Golgi apparatus and a more abundant occurrence of lipid droplets--a picture which persisted even in 30 min.--showed that the intensified elaborative activity of dark pinealocytes, a minor cell population, was of longer duration in comparison with light pinealocytes. The subsequent fall in their stress-reactive response points out that the function of light and dark pinealocytes is driven by different regulative systems. Based on the principle that the function is the reflection of morphometabolic changes, in can be concluded that 10 min. after the injection act, the pineal gland has a short-term crescendo of its stress-reactive response. The morphine injection did not cause any significant changes in both pinealocyte populations in 10 min. A considerable increase of the relative volume of the constituents of the membrane elaborative compartment was found in light pinealocytes in the next observational periods, i.e., in the 20-th and the 30-th min. The lack of any conspicuous signs of an enhanced secretory activity, in contrast with frequent findings of lipid droplets and prosecretory granules, shows that the facilitation of the elaborative activity leads more to a restitution and increase of the pinealocyte potential than to a stimulation of their current secretion. Characteristic of this period was a frequent finding of newly generated lipid droplets. Their presence within the fields of GER tubules, as well as the communication of the lumens of these tubules with the matrix of the arising lipid droplet suggest a close connection of lipid droplets with the pinealocyte peptidergic activity Unexpected was the finding of a conglomerate of fasciculated lamellae--structures of a so far unknown function.(ABSTRACT TRUNCATED AT 400 WORDS)

Characteristics of a prompt morphodynamic response of the pineal gland to an acute ACTH injection.

The morphodynamic response of the pineal gland in the period 5-30 min after a single ACTH injection was studied. In 5 min a saline injection, functioning as a control, elicited a prompt release of the pineal active compounds advocated to be contained in clear vesicles and structures traditionally labeled lipid droplets. In the subsequent time period, 15 min, a rise in the relative volume of the granular endoplasmic reticulum (GER) and the Golgi apparatus, as well as prosecretory granules, was interpreted as a sign of an increased pinealocyte activity which leads to the restoration of the pineal gland endocrine potential. A decline in the increased mass of this membranous elaborative compartment in 30 min could be understood as an illustration of the stabilisation of the pinealocyte stress-evoked response. The ACTH injection did not apparently change the pattern of the morphodynamic pinealocyte response promoted by the saline injection in 5 min. However, starting from 15 min, a significant increase of the mass of GER and the Golgi apparatus was found in both pinealocyte populations. The augmented presence of prosecretory granules and lipid droplets, in comparison with the saline-injected animals in the respective time period, as well as the absence of a clearly observable evidence of the pinealocyte secretory activity pointed out that the ACTH stimulative action on the pinealocyte membranous elaborative compartment rather facilitated the pinealocyte endocrine recovery than supported their current secretory activity. From the functional viewpoint, the results obtained suggest that a stress-induced ACTH burst could modulate the post-secretory restitution of the endocrine potential of previously stress-activated pinealocytes.

Morphodynamic reactive response of the pineal gland of rats chronically exposed to stable strong magnetic field.

Mature male Wistar rats were affected by a strong magnetic field of 0.70 T for 20 min per day for 2 weeks. A short distance between the electromagnet pole expansions allowed interposition of one restrained animal only. The results obtained showed that the immobilization stress increased the peptidergic activity of both light and dark pinealocytes. In the animals exposed to the magnetic field, a dual morphodynamic response was observed: the peptidergic activity of light pinealocytes was obviously reduced versus the unimpaired stress-stimulated functional engagement of dark pinealocytes. The probability that the retina----pineal gland magnetoreceptor-magnetoeffector circuit is formed through the accentuation of the suppression of the noradrenaline input on light pinealocytes is discussed. It is also hypothesized that a potentially harmful bioeffect of a strong magnetic field could be manifested second to the impairment of the activity of light pinealocytes in organisms coping with stress.

Adrenal-mediated depression of N-acetyltransferase activity and melatonin levels in the rat pineal gland.

N-acetyltransferase (NAT) is believed to be the rate-limiting enzyme in the synthesis of melatonin from serotonin in the pineal gland. Norepinephrine released from sympathetic nerve endings within the pineal gland stimulates NAT activity and, therefore, melatonin synthesis. When an animal is subjected to a stressful stimulus, it would be expected that the increase in plasma stimulus, it would be expected that the increase in plasma catecholamines originating from the adrenal medulla and/or the sympathetic nervous system would result in a stimulation of pineal NAT activity. Adult male rats were given a 1.5cc injection of physiological saline subcutaneously into the back leg. Compared to non-injected controls, animals stressed in this manner were shown to have significantly lower pineal melatonin content 10 min after the saline injection late in the light phase of the light/dark cycle (at 18.30 h-lights on at 07.00 h). To test this more thoroughly, a time course study was conducted during the dark phase (at 02.00 h-5 hours after lights out) when pineal NAT activity and melatonin levels are either increasing or elevated. NAT activity and melatonin levels in the pineal were significantly depressed in stressed animals as compared to controls by 10 min after the saline injection, and remained so until 60 min after injection. By 90 min they had returned to control values. In the next study the nighttime response of the pineal to stress was compared in intact and adrenalectomized rats. Adrenalectomy prevented the changes in NAT activity and melatonin content associated with the saline injection. Some factor, such as a catecholamine or corticosterone from the adrenal, seems to be eliciting the response in the pineal to the saline injection. It is not known if the factor is acting centrally or directly on the pineal gland.

Responsiveness of pineal N-acetyltransferase and melatonin in the cotton rat exposed to either artificial or natural light at night.

In three separate experiments, the effect of acute exposure to either artificial or natural light during darkness of pineal N-acetyltransferase (NAT) activity and melatonin content was studied in the cotton rat (Sigmodon hispidus). The exposure of animals to an artificial-light irradiance of 160,000 microW/cm2 during darkness for either 1 s, 5 s, or 30 min was followed by a precipitous decline in pineal NAT activity and melatonin content when measured at either 15 or 30 min after light onset. When cotton rats were acutely exposed to light at night for 5 s, irradiances of either 3.2, 32, 320, and 3,200 did not suppress either pineal NAT or melatonin 30 min later; however, if the 5-s exposure had an irradiance of either 32,000 or 160,000 microW/cm2, the pineal enzyme activity and indole content were depressed. Moonlight, which had a maximal irradiance of 0.32 microW/cm2, was unable to suppress pineal NAT activity and melatonin content even when the animals were exposed to the moonlight for 30 min. The treatment of cotton rats with either norepinephrine or its agonist, isoproterenol, before their exposure to light at night retarded slightly the suppressive effect of light on the pineal constituents measured. Also, these drug treatments suppressed the pre-exposure levels of both NAT activity and melatonin content in the cotton rat pineal gland.

Morphodynamic response of the pineal gland to initial stress attack.

The influence of an initial stress attack (a subcutaneous saline injection plus rough handling) on the morphofunctional behaviour of the pineal gland was studied. Both light and electron microscopy pointed to an enhanced endocrine activity on the gland parenchyma. The occurrence of the clusters of highly activated light pinealocytes, as well as the appearance of two functionally different types of these cells, revealed that the introduction of the pineal gland to a new stress-induced steady state was based on the gradual promotion of a number of pinealocytes to the level of a high activity. Dark pinealocytes were less numerous and rather engaged in the synthesis than in the secretion. The ultrastructural characteristics of both pinealocyte populations show that the pineal gland meets the secretory demands upon an initial stress attack by a striking discharge of its active compounds and a successive activation of a new elaborative cycle. The morphodynamic conclusion about an enhanced pineal gland secretory activity is fully evaluated in the change of the rate of prolactin surge. A possible impact of the morphodynamic reactivity of the endocrine parenchyma of the pineal gland upon the functional interpretation of the morphological properties of pinealocytes in case of some manipulative procedures with animals was discussed.

A routine fitting of kinetic data to sums of exponentials with a programmable calculator.

The effects of prolonged ingestion of ethyl alcohol on the elimination kinetics of bromsulphalein (BSP) from the plasma and the excretion of the dye into bile after a single intravenous injection into the circulation of the rat were examined by means of the colorimetrical technique. Simple numerical methods for fitting the experimental data to polyexponential and convex upward functions were also proposed. Two multioptional programs written for the Texas Instrument 59 programmable calculator and for the Sharp 1500 pocket computer were developed which provide for fully automated exponential stripping of pharmacokinetic data and which will allow workers to calculate the numerical values of all the coefficients and exponents for the tracer function fitting the monotone sequences of data.

[Preliminary results of experimental reanastomosis of uterine horns of laboratory rats after sterilization]. / Preliminarni rezultati eksperimentalnih reanostomoza rogova uterusa laboratorijskih pacova nakon prethodne sterilizacije.

The goal of the launched studies was to analyse, on an experimental model, the histophysiological properties of the segments of the rat's uterine horns after end-to-end anastomoses by the microsurgery technique. Sexually mature females of the laboratory Winster strain were used. Eight weeks after the uterine horns were ligated for sterilization, reanastomosomes were performed. One group of animals was given hydrocortisone for 8 days postoperatively. The results of the observation of the sites of anastomosis has shown that the use of the microsurgery technique allows an almost ideal reconstruction of the cut segments. The absence of chronic interstitial changes in the endometrium, a decreased presence of connective-muscular tissues within the stroma and the RES system cells in animals having received hydrocortisone in relation to those who have not -- all this indicates that the postoperative use of hydrocortisone decreases both the "reactive" growth of the connective tissue and the RES system cells.