Total Granule Research Articles

The Heberprot-P in the 21st century

Introduction: Heberprot-P, considered the medicine of the 21st century for the healing of diabetic feet, is emerging as a promising technique for the repair of destroyed or damaged tissues. Objective: To present the results of the use of intra- and perilesional Heberprot-P in complex ulcers in the province of Pinar del Rio, Cuba from 2022 to 2024. Methods: a descriptive, retrospective, cross-sectional study of the use of Heberprot-P 75 mcg was developed. intra and perilesional in patients with complex ulcers from January 2022 to March 2024 in the province Pinar del Río, Cuba, with a total of 8482 lesions and an intentional sample of 181 complex ulcers. Inclusion criteria: presence of complex ulcers in the lower limbs. Exclusion criteria: those who did not meet the inclusion criteria with prior signing of the informed consent. Results: non-complex ulcers were more frequent, for 98%, diabetic foot represented 81% of complex ulcers, these with a higher rate of major amputation, hospitalization and intralesional infiltrations, with 18 doses (6 weeks, 42 days ) to achieve total granulation, correspondingly the time for closure by secondary intention was longer, 6 weeks after its application (84 days in total). Conclusions: the use of intra- and perilesional Heberprot-P is an effective therapy to accelerate granulation and closure by secondary intention of complex wounds that are difficult to heal.

Investigation on energy and mass distribution characteristics of granules in the composite heat exchanger

A composite heat exchanger for high-temperature granule waste heat recovery is proposed. Granular mass and energy distribution within the composite heat exchanger are simulated via the CFD-DEM coupling method. The effects of granular size, cooling gas velocity, and granular mass flow rate on granular distribution and the temperature distribution are analyzed. Results demonstrated that under the combined action of airflow impact force and gravity, the granule produces an uneven distribution in time and space. Larger granule tends to be positioned closer to the gas inlet horizontally. Along the direction from the gas inlet to the gas outlet, granules exhibit a trend of decreasing size, mass, and temperature. The influence of gas velocity predominantly affects the area coverage rate, whereas the effect of granular mass flow rate is minimal. The area coverage rate initially increases with rising gas velocity and subsequently decreases, peaking at 73.8% at 12 m/s. After the heat exchange process reached a stable state, the number of contacting granules accounted for only 0.37% of the total granules, making heat conduction between granules negligible. Convective heat transfer dominates, accounting for approximately 86.52% of the total heat exchange, while radiation heat transfer accounts for about 13.48%.

Modelling adult neurogenesis in the aging rodent hippocampus: a midlife crisis.

Contrary to humans, adult hippocampal neurogenesis in rodents is not controversial. And in the last three decades, multiple studies in rodents have deemed adult neurogenesis essential for most hippocampal functions. The functional relevance of new neurons relies on their distinct physiological properties during their maturation before they become indistinguishable from mature granule cells. Most functional studies have used very young animals with robust neurogenesis. However, this trait declines dramatically with age, questioning its functional relevance in aging animals, a caveat that has been mentioned repeatedly, but rarely analyzed quantitatively. In this meta-analysis, we use data from published studies to determine the critical functional window of new neurons and to model their numbers across age in both mice and rats. Our model shows that new neurons with distinct functional profile represent about 3% of the total granule cells in young adult 3-month-old rodents, and their number decline following a power function to reach less than 1% in middle aged animals and less than 0.5% in old mice and rats. These low ratios pose an important logical and computational caveat to the proposed essential role of new neurons in the dentate gyrus, particularly in middle aged and old animals, a factor that needs to be adequately addressed when defining the relevance of adult neurogenesis in hippocampal function.

Differential vulnerability of the dentate gyrus to tauopathies in dementias

The dentate gyrus (DG), a key hippocampal subregion in memory processing, generally resists phosphorylated tau accumulation in the amnestic dementia of the Alzheimer’s type due to Alzheimer’s disease (DAT-AD), but less is known about the susceptibility of the DG to other tauopathies. Here, we report stereologic densities of total DG neurons and tau inclusions in thirty-two brains of human participants with autopsy-confirmed tauopathies with distinct isoform profiles—3R Pick’s disease (PiD, N = 8), 4R corticobasal degeneration (CBD, N = 8), 4R progressive supranuclear palsy (PSP, N = 8), and 3/4R AD (N = 8). All participants were diagnosed during life with primary progressive aphasia (PPA), an aphasic clinical dementia syndrome characterized by progressive deterioration of language abilities with spared non-language cognitive abilities in early stages, except for five patients with DAT-AD as a comparison group. 51% of total participants were female. All specimens were stained immunohistochemically with AT8 to visualize tau pathology, and PPA cases were stained for Nissl substance to visualize neurons. Unbiased stereological analysis was performed in granule and hilar DG cells, and inclusion-to-neuron ratios were calculated. In the PPA group, PiD had highest mean total (granule + hilar) densities of DG tau pathology (p < 0.001), followed by CBD, AD, then PSP. PPA-AD cases showed more inclusions in hilar cells compared to granule cells, while the opposite was true in PiD and CBD. Inclusion-to-neuron ratios revealed, on average, 33% of all DG neurons in PiD cases contained a tau inclusion, compared to ~ 7% in CBD, 2% in AD, and 0.4% in PSP. There was no significant difference between DAT-AD and PPA-AD pathologic tau burden, suggesting that differences in DG burden are not specific to clinical phenotype. We conclude that the DG is differentially vulnerable to pathologic tau accumulation, raising intriguing questions about the structural integrity and functional significance of hippocampal circuits in neurodegenerative dementias.

AGLOMERATION OF Al2O3 NANOMETRIC AND SUBMICROMETRIC PARTICLES BY SPRAY DRYING FOR THEIR USE AS FEEDSTOCK IN THERMAL SPRAYING COATINGS

This study focuses on optimizing the parameters of the spray-drying process for the agglomeration of both nanometric and submicrometric Al2O3 particles for their use as feedstock to manufacture thermally sprayed coatings. Initially, for an aqueous suspension with submicrometric alumina particles, d10 = 0.8 to d90 = 2.0 µm, named SA, was evaluated the effect of: i) The solids percentage in the aqueous suspension, ii) the feed flow rate and iii) the hot air rate used to evaporate the water in the suspension, on the agglomeration efficiency and the morphology of agglomerated obtained, utilizing a factorial experimental design with three factors and two levels. The agglomeration efficiency was calculated as the ratio between the weight percentage of granulated particles and the weight of solids in the sprayed slurry, while the morphology was analyzed by scanning electron spectroscopy SEM. The agglomeration results for the SA suspension indicate that the highest efficiency was achieved with a solid percentage in an aqueous suspension of 30 wt. % (10 vol.%), a feed rate of 3.1 ml/min and a hot air rate of 5.5 m3/min at a temperature of 220 °C, obtaining spherical agglomerates. Nevertheless, different morphologies of agglomerate were obtained based on the others experimental runs, such as hollow spheres. Subsequently, these parameters were replicated for a suspension of alumina nanoparticles, d50=80 nm, called NA, to obtain granules with a spherical morphology, composed of primary and secondary agglomerates whose size distributions correspond to d10 = 5 to d90 = 11 µm and d10 = 30 to d90 = 44 µm, respectively, with a total granulation efficiency of 80%, of which, 90% have a suitable range size to be used as raw material in the production of coatings by means of thermal spraying.

High-Shear Wet Granulation of SMEDDS Based on Mesoporous Carriers for Improved Carvedilol Solubility.

Mesoporous carriers are a convenient choice for the solidification of self-microemulsifying drug delivery systems (SMEDDS) designed to improve the solubility of poorly water-soluble drugs. They are known for high liquid load capacity and the ability to maintain characteristics of dry, free-flowing powders. Therefore, five different mesoporous carriers were used for the preparation of carvedilol-loaded SMEDDS granules by wet granulation methods—in paten (manually) and using a high-shear (HS) granulator. Granules with the highest SMEDDS content (63% and 66% of total granules mass, respectively) and suitable flow properties were obtained by Syloid® 244FP and Neusilin® US2. SMEDDS loaded granules produced by HS granulation showed superior flow characteristics compared to those obtained manually. All SMEDDS granules exhibited fast in vitro release, with 93% of carvedilol releasing from Syloid® 244FP-based granules in 5 min. Upon compaction into self-microemulsifying tablets, suitable tablet hardness and very fast disintegration time were achieved, thus producing orodispersible tablets. The compaction slightly slowed down the carvedilol release rate; nevertheless, upon 1 h (at pH 1.2) or 4 h (at pH 6.8) of in vitro dissolution testing, the amount of released drug was comparable with granules, confirming the suitability of orodispersible tablets for the production of the SMEDDS loaded single unit oral dosage form.

Lipid droplet accumulation in β cells in patients with type 2 diabetes is associated with insulin resistance, hyperglycemia and β cell dysfunction involving decreased insulin granules.

Background and objectivePancreatic fat is a form of ectopic fat. Lipid droplets (LDs) are also observed in β cells; however, the pathophysiological significance, especially for β cell function, has not been elucidated. Our aim was to assess LD accumulation in β cells in various stages of glucose intolerance and to clarify its relationship with clinical and histological parameters.MethodsWe examined 42 Japanese patients who underwent pancreatectomy. The BODIPY493/503-positive (BODIPY-positive) area in β cells was measured in pancreatic sections from 32 patients. The insulin granule numbers were counted in an additional 10 patients using electron microscopy.ResultsThe BODIPY-positive area in β cells in preexisting type 2 diabetes patients was higher than that in normal glucose tolerance patients (p = 0.031). The BODIPY-positive area in β cells was positively correlated with age (r = 0.45, p = 0.0097), HbA1c (r = 0.38, p = 0.0302), fasting plasma glucose (r = 0.37, p = 0.045), and homeostasis model assessment insulin resistance (r = 0.41, p = 0.049) and negatively correlated with an increase in the C-peptide immunoreactivity level by the glucagon test (r = -0.59, p = 0.018). The ratio of mature insulin granule number to total insulin granule number was reduced in the patients with rich LD accumulation in β cells (p = 0.039).ConclusionsType 2 diabetes patients had high LD accumulation in β cells, which was associated with insulin resistance, hyperglycemia, aging and β cell dysfunction involving decreased mature insulin granules.

Broadcasting of tiny granules by drone to mimic liquid spraying for the control of fall armyworm (Spodoptera frugiperda).

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is an invasive pest. Maize is one of its preferred host plants. The traditional application of granules has been effective for the control of FAW. Nevertheless, the challenge is to develop an application method that is less labor-intensive and also efficient. Tiny granules in the size range of 0.38-0.55 mm were prepared by the centrifugal granulation method for drone application. The in-swath distribution patterns of granules deposited on sticky tapes were similar to the distribution of aqueous droplets through drone spraying. In the range of 1.5-3.5m, a relatively higher aircraft height of flight can provide a more uniform distribution pattern of deposited granules, but resulted in less deposit of tiny granules in the whorl of maize plants. Similarly, the deposit of granules in the whorl of maize plants significantly decreased when the flight speed increased from 4 to 6m s-1 . Granules gathered in the whorl accounted for 50.8-58.7% of total granules deposited in the maize canopy. The field experiment demonstrates granular formulations (containing 0.25% chlorantraniliprole +0.15% emamectin benzoate, or higher concentrations) can provide better and longer duration of FAW control than the aqueous spray formulation at the whorl stage of maize plants. Broadcasting of tiny granules by drone can provide better FAW control than liquid spray. The architecture of the maize plant and the downward airstream of the drone create favorable conditions for the deposition of granules in whorls. © 2021 Society of Chemical Industry.

INCREASING UTILIZATION OF PRODUCTION MACHINERY THROUGH LINE BALANCING APPROACH (CASE STUDY ON PHARMACEUTICAL INDUSTRY)

The growth in sales volume of unbranded generic products (considering that drugs served by BPJS Kesehatan refer to the National Formulary and e-catalogs set by the government) has led to a decline in margins as price competition intensifies. The purpose of this research is to optimize the utilization and efficiency of the machine, increase productivity and balance the line. Improvements are made by following the ECRS (Eliminating, Combining, Rearranging, and Simplify) based line balancing concept. From the improvements that have been made to the granulation process, it was found that the time of the wet mixing process, wet sieving, drying, and dry sieving had decreased. Cycle time decreased, output increase, the total granulation process time “Product F” decreased. Line efficiency increased, balance delay decreased and smoothness index decreased. This shows that the granulation line is getting more balanced

Enhancing stability of aerobic granules by microbial selection pressure using height-adjustable influent strategy

Optimizing granules size distribution is critical for both reactor performance and stability. In this research, an optimal size range of 1800 to 3000 μm was proposed regarding mass transfer and granules stability based on granules developed at DO around 8.0 mg L−1 with the feed COD:N:P at 100:5:1. A height-adjustable influent strategy was applied to facilitate the nutrient storage of granules at optimum size range via microbial selective pressure. Results suggested insufficient hydraulic shear stress led to overgrowth of granules size. High abundance of filamentous bacteria (Thiothrix sp.) was observed in oversized granules, which detached and affected the remaining granules, resulting in severe sludge bulking. Strong hydraulic shear stress suppressed uncontrolled growth of granules. However, fewer abundance of simultaneous nitrification and denitrification (SND) bacterium was acquired, which led to unfavored SND effect and total nitrogen (TN) removal efficiency. The height-adjustable influent strategy facilitated the poly-β-hydroxybutyrate (PHB) storage of granules at optimum size range, while limiting the overgrowth of granules size. Additionally, more than 87.51% of total granules situated in optimal sizes range, which led to higher abundance of SND bacterium and higher TN removal efficiency.

Early postnatal irradiation\u2010induced age\u2010dependent changes in adult mouse brain: MRI based characterization

BackgroundBrain radiation exposure, in particular, radiotherapy, can induce cognitive impairment in patients, with significant effects persisting for the rest of their life. However, the main mechanisms leading to this adverse event remain largely unknown. A study of radiation-induced injury to multiple brain regions, focused on the hippocampus, may shed light on neuroanatomic bases of neurocognitive impairments in patients. Hence, we irradiated BALB/c mice (male and female) at postnatal day 3 (P3), day 10 (P10), and day 21 (P21) and investigated the long-term radiation effect on brain MRI changes and hippocampal neurogenesis.ResultsWe found characteristic brain volume reductions in the hippocampus, olfactory bulbs, the cerebellar hemisphere, cerebellar white matter (WM) and cerebellar vermis WM, cingulate, occipital and frontal cortices, cerebellar flocculonodular WM, parietal region, endopiriform claustrum, and entorhinal cortex after irradiation with 5 Gy at P3. Irradiation at P10 induced significant volume reduction in the cerebellum, parietal region, cingulate region, and olfactory bulbs, whereas the reduction of the volume in the entorhinal, parietal, insular, and frontal cortices was demonstrated after irradiation at P21. Immunohistochemical study with cell division marker Ki67 and immature marker doublecortin (DCX) indicated the reduced cell division and genesis of new neurons in the subgranular zone of the dentate gyrus in the hippocampus after irradiation at all three postnatal days, but the reduction of total granule cells in the stratum granulosun was found after irradiation at P3 and P10.ConclusionsThe early life radiation exposure during different developmental stages induces varied brain pathophysiological changes which may be related to the development of neurological and neuropsychological disorders later in life.

Relationships of flour characteristics with Isolated Starch Properties in Different Chinese Wheat Varieties

Flour and isolated total starch granules (TS), A-type starch granules (AS), and B-type starch granules (BS) characteristics as well as their relationships were evaluated. Flour from varieties with higher grain hardness index (GHI) exhibited higher damaged starch content, SDS-sedimentation values (SDS), and water SRC (W-SRC). GHI showed a negative correlation with breakdown viscosity (BDV) and swelling power of TS while positive with solubility of BS. BS from varieties with higher hardness showed lower pasting viscosity compared to that from lower hardness. Damaged starch, W-SRC, Sucrose SRC (S-SRC), water absorption, and extensional resistance of flour showed a negative correlation with AS content. Protein content, SDS, curve area, and extensional resistance of flour showed a negative correlation with BDV and setback viscosity (SV) of TS. Damage starch, W-SRC, and S-SRC of flour showed a positive correlation with pasting viscosities and solubility of BS while negative with swelling power of TS and AS. Pasting properties of flour showed a positive correlation with BDV, SV, and gel hardness of BS while negative with solubility, gel springiness, and cohesiveness of BS. The results demonstrated wheat flour and starch characteristics were related to grain texture, furthermore, starch granule size affected flour functionality and end-use quality.

Characteristics of normal human retinal pigment epithelium cells with extremes of autofluorescence or intracellular granule count.

Background:Cells of the retinal pigment epithelium (RPE) accumulate different kinds of granules (lipofuscin, melanolipofuscin, melanosomes) within their cell bodies, with lipofuscin and melanolipofuscin being autofluorescent after blue light excitation. High amounts of lipofuscin granules within the RPE have been associated with the development of RPE cell death and age-related macular degeneration (AMD); however, this has not been confirmed in histology so far. Here, based on our previous dataset of RPE granule characteristics, we report the characteristics of RPE cells from human donor eyes that show either high or low numbers of intracellular granules or high or low autofluorescence (AF) intensities.Methods:RPE flatmounts of fifteen human donors were examined using high-resolution structured illumination microscopy (HR-SIM) and laser scanning microscopy (LSM). Autofluorescent granules were analyzed regarding AF phenotype and absolute number of granules. In addition, total AF intensity per cell and granule density (number of granules per cell area) were determined. For the final analysis, RPE cells with total granule number below 5th or above the 95th percentile, or a total AF intensity ± 1.5 standard deviations above or below the mean were included, and compared to the average RPE cell at the same location. Data are presented as mean ± standard deviation.Results:Within 420 RPE cells examined, 42 cells were further analyzed due to extremes regarding total granule numbers. In addition, 20 RPE cells had AF 1.5 standard deviations below, 28 RPE cells above the mean local AF intensity. Melanolipofuscin granules predominate in RPE cells with low granule content and low AF intensity. RPE cells with high granule content have nearly twice (1.8 times) as many granules as an average RPE cell.Conclusions:In normal eyes, outliers regarding autofluorescent granule load and AF intensity signals are rare among RPE cells, suggesting that granule deposition and subsequent AF follows intrinsic control mechanisms at a cellular level. The AF of a cell is related to the composition of intracellular granule types. Ongoing studies using AMD donor eyes will examine possible disease related changes in granule distribution and further put lipofuscińs role in aging and AMD further into perspective.

Normal and defective pathways in biogenesis and maintenance of the insulin storage pool.

Both basal and glucose-stimulated insulin release occur primarily by insulin secretory granule exocytosis from pancreatic β cells, and both are needed to maintain normoglycemia. Loss of insulin-secreting β cells, accompanied by abnormal glucose tolerance, may involve simple exhaustion of insulin reserves (which, by immunostaining, appears as a loss of β cell identity), or β cell dedifferentiation, or β cell death. While various sensing and signaling defects can result in diminished insulin secretion, somewhat less attention has been paid to diabetes risk caused by insufficiency in the biosynthetic generation and maintenance of the total insulin granule storage pool. This Review offers an overview of insulin biosynthesis, beginning with the preproinsulin mRNA (translation and translocation into the ER), proinsulin folding and export from the ER, and delivery via the Golgi complex to secretory granules for conversion to insulin and ultimate hormone storage. All of these steps are needed for generation and maintenance of the total insulin granule pool, and defects in any of these steps may, weakly or strongly, perturb glycemic control. The foregoing considerations have obvious potential relevance to the pathogenesis of type 2 diabetes and some forms of monogenic diabetes; conceivably, several of these concepts might also have implications for β cell failure in type 1 diabetes.

Traumatic brain injury modifies synaptic plasticity in newly-generated granule cells of the adult hippocampus

The hippocampus is vulnerable to traumatic brain injury (TBI), and hippocampal damage is associated with cognitive deficits that are often the hallmark of TBI. Recent studies have found that TBI induces enhanced neurogenesis in the dentate gyrus (DG) of the hippocampus, and this cellular response is related to innate cognitive recovery. However, cellular mechanisms of the role of DG neurogenesis in post-TBI recovery remain unclear. This study investigated changes in long-term potentiation (LTP) within the DG in relation to TBI-induced neurogenesis. Adult male rats received a moderate TBI or sham injury and were sacrificed for brain slice recordings at 30 or 60 days post-injury. Recordings were taken from the medial perforant path input to DG granule cells in the presence or absence of the GABAergic antagonist picrotoxin, reflecting activity of either all DG granule cells or predominately newborn granule cells, respectively. Measurements of LTP observed in the total granule cell population (with picrotoxin) showed a prolonged impairment which worsened between 30 and 60 days post-TBI. Under conditions which predominantly reflected the LTP elicited in newly born granule cells (no picrotoxin), a strikingly different pattern of post-TBI changes was observed, with a time-dependent cycle of functional impairment and recovery. At 30 days after injury this cell population showed little or no LTP, but by 60 days the capacity for LTP of the newly born granule cells was no different from that of sham controls. The time-frame of LTP improvements in the newborn cell population, comparable to that of behavioral recovery reported previously, suggests the unique functional properties of newborn granule cells enable them to contribute to restorative change following brain injury.

Morphological and phenotypical diversity of eosinophils in the rat ileum

Eosinophils are abundantly present in intestinal mucosa. However, the morphological characteristics of their cellular population are still largely unknown. In this study, we examine their characteristics in the rat ileal mucosa using histological and ultrastructural methods. The results indicated that ileal eosinophils could be distinguished into two main groups based on their nuclear shapes and distribution: eosinophils with spheric or reniform nuclei mainly localized in the villous region and eosinophils with annular or bacilliform nuclei as the major population around crypts. Immunohistochemical analysis revealed that all eosinophils in the lamina propria (LP) were immunopositive for CD11b, whereas eosinophils in LP of the intestinal villus but not those in LP around the crypt, were immunopositive for CD11c. Three-dimensional ultrastructural analysis using serial block-face scanning electron microscopy showed that the eosinophils with spheric or reniform nuclei were abundant in the upper portions of the intestinal villus, whereas those with annular nuclei were abundant in the lower portions of the intestinal villus and around crypts. The eosinophils with spheric or reniform nuclei possessed broader cellular bodies with greater abundance of surface projections compared with those with annular nuclei. Eosinophils in the upper portions of intestinal villus frequently extended their cellular bodies into the intraepithelial space. The number of total and eosinophil-specific granules was positively correlated with the minor axis of the nuclear holes in the annular nuclei. These data suggest that ileal eosinophils exhibit not homogenous but rather diverse characteristics, possible due to the mixture of eosinophils at different maturation and/or activation stages.

Adult hippocampal neurogenesis in Egyptian fruit bats from three different environments: Are interpretational variations due to the environment or methodology?

We quantified both proliferative (Ki-67 immunohistochemistry) and immature (doublecortin immunohistochemistry) cells within the dentate gyrus of adult Egyptian fruit bats from three distinct environments: (a) primary rainforest, (b) subtropical woodland, and (c) fifth-generation captive-bred. We used four different previously reported methods to assess the effect of the environment on proliferative and immature cells: (a) the comparison of raw totals of proliferative and immature cells; (b) these totals standardized to brain mass; (c) these totals expressed as a density using the volume of the granular cell layer (GCLv) for standardization; and (d) these totals expressed as a percentage of the total number of granule cells. For all methods, the numbers of proliferative cells did not differ statistically among the three groups, indicating that the rate of proliferation, while malleable to experimental manipulation or transiently in response to events of importance in the natural habitat, appears to occur, for the most part, at a predetermined rate within a species. For the immature cells, raw numbers and standardizations to brain mass and GCLv revealed no difference between the three groups studied; however, standardization to total granule cell numbers indicated that the two groups of wild-caught bats had significantly higher numbers of immature neurons than the captive-bred bats. These contrasting results indicate that the interpretation of the effect of the environment on the numbers of immature neurons appears method dependent. It is possible that current methods are not sensitive enough to reveal the effect of different environments on proliferative and immature cells.

Chromogranin B regulates early-stage insulin granule trafficking from the Golgi in pancreatic islet β-cells.

Chromogranin B (CgB, also known as CHGB) is abundantly expressed in dense core secretory granules of multiple endocrine tissues and has been suggested to regulate granule biogenesis in some cell types, including the pancreatic islet β-cell, though the mechanisms are poorly understood. Here, we demonstrate a critical role for CgB in regulating secretory granule trafficking in the β-cell. Loss of CgB impairs glucose-stimulated insulin secretion, impedes proinsulin processing to yield increased proinsulin content, and alters the density of insulin-containing granules. Using an in situ fluorescent pulse-chase strategy to track nascent proinsulin, we show that loss of CgB impairs Golgi budding of proinsulin-containing secretory granules, resulting in a substantial delay in trafficking of nascent granules to the plasma membrane with an overall decrease in total plasma membrane-associated granules. These studies demonstrate that CgB is necessary for efficient trafficking of secretory proteins into the budding granule, which impacts the availability of insulin-containing secretory granules for exocytic release.This article has an associated First Person interview with the first author of the paper.

Design and evaluation of rhubarb total free anthraquinones oral colon-specific drug delivery granules to improve the purgative effect

Rhubarb is commonly used as a cathartic in Asian countries. However, researchers have devotedextensive concerns to the quality control and safety of rhubarb and traditional Chinese preparations composed of rhubarb due to the instable purgative effect and potential nephrotoxicity of anthraquinones. In this study, we aimed to prepare rhubarb total free anthraquinones (RTFA) oral colon-specific drug delivery granules (RTFA-OCDD-GN) to delivery anthraquinones to colon to produce purgative effect. RTFA-OCDD-GN were prepared using chitosan and Eudragit S100 through a double-layer coating process and the formulation was optimized. Continuous release studies were performed in a simulated gastric fluid (pH 1.2), followed by a small-intestinal fluid (pH 6.8) and a colonic fluid (pH 7.4, containing rat cecal contents). The purgative effect test was performed in rats. The dissolution profile of RTFA-OCDD-GN showed that the accumulative dissolution rate of RTFA was about 83.0% in the simulated colonic fluid containing rat cecal contents and only about 9.0% in the simulated gastrointestinal fluids. And the RTFA-OCDD-GN could produce the comparative purgative activity as rhubarb, suggesting it could deliver the free AQs to the colon. The RTFA-OCDD-GN was a useful media to enhance the purgative activity of free anthraquinones after administered orally.

Single Degranulations in NK Cells Can Mediate Target Cell Killing.

NK cells are cytotoxic lymphocytes important in defense against viral infection and cancer. NK cells mediate cytotoxicity predominantly through directed secretion of lytic granules, which are specialized lysosome-related organelles, containing effector molecules such as perforin and granzymes. Although many requirements for lytic granule transport to, and secretion at, the NK cell lytic synapse are known, the minimum number of degranulation events required by an NK cell to kill its target is unknown. We performed high-resolution four-dimensional confocal microscopy of human NK-target cell conjugates to quantify NK cell degranulation (using a degranulation indicator, LAMP-1-pHluorin) as well as target cell death. Despite containing almost 200 granules, we found that an individual NK cell needed only two to four degranulation events, on average, to mediate target cell death. Although NK cells released approximately one-tenth of their total lytic granule reserve upon a single target, they required just over one-hundredth of their total lytic granules to kill a target cell. Importantly, the kinetics of NK cell killing correlated to the size of and the amount of effector molecules contained within lytic granules, as well as the temporal, but not spatial, organization of degranulation events. Thus, our study answers a fundamental question as to how many degranulation events it takes for a human NK cell to kill its target.