Microscopic Image Analysis System Research Articles

The development of an automated microscope image tracking and analysis system.

Microscopy image analysis plays a crucial role in understanding cellular behavior and uncovering important insights in various biological and medical research domains. Tracking cells within the time-lapse microscopy images is a fundamental technique that enables the study of cell dynamics, interactions, and migration. While manual cell tracking is possible, it is time-consuming and prone to subjective biases that impact results. In order to solve this issue, we sought to create an automated software solution, named cell analyzer, which is able to track cells within microscopy images with minimal input required from the user. The program of cell analyzer was written in Python utilizing the open source computer vision (OpenCV) library and featured a graphical user interface that makes it easy for users to access. The functions of all codes were verified through closeness, area, centroid, contrast, variance, and cell tracking test. Cell analyzer primarily utilizes image preprocessing and edge detection techniques to isolate cell boundaries for detection and analysis. It uniquely recorded the area, displacement, speed, size, and direction of detected cell objects and visualized the data collected automatically for fast analysis. Our cell analyzer provides an easy-to-use tool through a graphical user interface for tracking cell motion and analyzing quantitative cell images.

Self-healing characteristics of cement concrete containing expansive agent

Many studies have been conducted to identify the self-healing effect in cementitious materials. However, the knowledge regarding the self-healing effect is insufficient to utilize this effect for design purposes. This study examined the influence of numerous admixtures such as expansive agents (EA), ultra-fine fly ash (UFFA), finely ground granulated blast furnace slag (FGGBS), and silica fume (SF) on the self-healing capacity of Portland cement concrete. Here, focused on investigating the effect of the expansive agent (EA) used in concrete mixtures to identify whether the EA could act as a self-healing trigger in concrete materials that are frequently used in a bridge deck overlay. Ordinary Portland cement concrete (OPC), latex-modified concrete (LMC), and silica fume concrete (SFC) was used to compare the effect of the EA (0,4,8%, and 12%) in the ternary blended cement concrete on each material for bridge deck overlay concrete. In this study, the crack width was examined at 0,7,14 and 28 days respectively which were inducement at 3 and 7 days age of concrete specimens by the microscopic image analysis system. Samples with healed cracks with a width range of 100–200 µm and EA ≥ 8% on day 28 exhibited faster self-healing performance. Additionally, we calculated the self-cracking closing ratio and performed a microstructure analysis by SEM/EDS. Moreover, the compressive strength was examined at 7, 28,56, and 90 days for understanding the improved performance of all concrete mixtures.

Gadolinium chelates inhibit intracellular calcium signaling in rat trigeminal ganglion neurons similar to rat dorsal root ganglion neurons, but less effective

Objectives: Gadolinium (Gd3+) based MR contrast agents (GBMCA) are manufactured with a chelation process, where organic ligand molecules form a stable complex around Gd3+. The aim of the present study was to investigate the possible impact of free gadolinium and GBMCA in ganglia (trigeminal and dorsal root) neuron cell cultures on intracellular calcium (Ca2+) since these agents could dissociate and lead to the release of toxic Gd3+ ions in metabolic conditions. Methods: Ganglia cells were studied for responses to agents and nonspecific depolarization by high KCl+ in Fura 2 AM loaded neurons by monitoring the changes in [Ca2+]i using a microscopic digital image analysis system. GBMCA and molecular gadolinium doses of 0.1 mmol/kg were prepared with the same pH and temperature and applied to the cells. Results: Application of Gd3+, gadobenate dimeglumine, gadobutrol and gadodiamide to rat ganglia neurons led to significant decreases in basal intracellular calcium levels, while gadoterate meglumine administration did not have a significant impact. As expected, Gd3+ was more effective when compared tı GBMCA. While the impact was almost full with gadodiamide, Gd3+ and other GBMCAs had irreversible effects at different levels. The impact of gadoterate meglumine was neglectable when compared to Gd3+ and other GBMCAs, although it exhibited slightly gadodiamide-like effects. Conclusions: In conclusion, gadolinium chelates released gadolinium and irreversibly reduced the intracellular calcium levels in identical TG and DRG cells at different levels.

Spironolactone Inhibits Cardiomyocyte Hypertrophy by Regulating the Ca2+/Calcineurin/p-NFATc3 Pathway.

This study aimed to investigate the protective effect and molecular mechanism of spironolactone in isoproterenol-induced cardiomyocyte hypertrophy. In this study, primary cardiomyocytes were extracted from the heart of neonatal rats. After stable culture, they were processed with isoproterenol alone or isoproterenol (10 μM) combined with different doses (low dose of 10 μM and high dose of 50 μM), and the cellular activity was determined by MTT experiment. The volume of cells was measured with an inverted microscope and CIAS-1000 cell image analysis system. The mRNA expression levels of ANP and BNP in cells were explored by RT-qPCR. The levels of ANP and BNP proteins and NFATc3 phosphorylation in the nucleus were detected by western blot. The extracellular Ca2+ concentration and CaN activity were measured by colorimetry with the kit. Isoproterenol significantly enlarged the volume of cardiomyocytes (p < 0.001), upregulated mRNA and expression levels of ANP and BNP proteins (p < 0.001), increased extracellular Ca2+ concentration and CaN activity (p < 0.001), and upregulated NFATc3 phosphorylation in the nucleus (p < 0.001). The volume of cells treated with isoproterenol combined with different doses of spironolactone significantly decreased compared with those treated with isoproterenol alone (p < 0.001). mRNA and expression levels of ANP and BNP proteins downregulated significantly (p < 0.001). The extracellular Ca2+ (p < 0.01) concentration and CaN activity (p < 0.001) decreased significantly, and NFATc3 phosphorylation in the nucleus downregulated significantly (p < 0.001). There was no significant difference in cell volume (p=0.999), ANP and BNP mRNA (p=0.695), expression levels of proteins, CaN activity (0.154), and NFATc3 phosphorylation in the nucleus between the cells treated with isoproterenol combined with high-dose spironolactone and those in the control group. In conclusion, spironolactone can reverse isoproterenol-induced cardiomyocyte hypertrophy by inhibiting the Ca2+/CaN/NFATc3 pathway.

Kirlenmiş Alanlardan Toplanan Akdeniz Midyesi'nin Ratlarda İmmünohistokimyasal Metotla Hepatotoksik Etkisi

Mussels (Mytilus galloprovincialis) are aquatic organisms that can accumulate all the factors that pollute the fresh and saltwater environment. Although the Dardanelles has been exposed to environmental pollution for many years, it is also an important region for crustaceans. We aimed to investigate the histopathological changes in the liver parenchyma which is an important gland of the digestive system by feeding these mussels to rats. Twenty-four male Wistar albino were used in the study. The first group (control): fed with standard rat feed, the second group (experiment 1): 4/5 mussel + 1/5 standard rat feed daily; third group (experiment 2): 4/5 mussel + 1/5 standard rat feed every other day, the fourth group (experiment 3): groups were formed with 4/5 mussel + 1/5 standard rat feed every three days. All liver tissue samples taken from the experimental and control groups were stained with hematoxylin-eosin, and immuohitochemically staining inflammatory marker TNF-α and NF-κB after routine histopathological follow-up and analyzed with a light microscope image analysis system. It was observed that mononuclear cells caused inflammation of portal areas, increased sinusoidal dilatation and congestion and degeneration due to vacuolization in hepatocytes in the liver parenchyma of mussel-fed rats. Besides, immunohistochemical staining, TNF-α, and NF-κB immunoreactivity were observed in the liver cells of especially in the second group of rats. As a result, it has been shown that the consumption of mussels obtained and marketed without considering environmental pollution may trigger important digestive system organs of liver diseases.

Immunohistochemical investigation of histopathological changes in the kidney tissue of mussel-fed rats

Purpose: The aim of this study was to determine the histopathological changes that the mussels, which serve as important filters of the sea, cause in rat kidney tissue. Materials and Methods: In our study, 24 female (Wistar albino 6-10 week old rats) rats were used. First group (n: 6): fed with standard rat food, second group (n: 6): fed everyday with 4/5 mussels + 1/5 standard rat food; third group (n: 6): fed 4/5 mussels + 1/5 standard rat food every two days; Fourth group (n: 6): were formed with 4/5 mussels + 1/5 standard rat food to be given every three days. After the routine histopathological follow-up, all kidney tissue samples taken and control groups were analyzed with Hematoxylin-Eosin staining, and the nephrotoxic effect was immunoshistochemically with TGF-β and NF-κB and analyzed with a light microscope image analysis system. Results: Mussel-fed rats were found to cause inflammation in the kidney tissue, dilatation in the distal and proximal tubules, shrinkage in the glomeruli and degeneration in the tubular epithelium. In immunohistochemical staining, TGF-β and NF-κB immunoreactivity increased due to cells leading to inflammation and apoptosis. The nephrotoxic effect was quite high especially in rats given daily mussels. Conclusion: The mussel provided in unsanitary conditions may cause damage in kidney tissue from the excretory system organs due to excess consumption.

Post-Antibiotic Effect of Ampicillin and Levofloxacin to Escherichia coli and Staphylococcus aureus Based on Microscopic Imaging Analysis.

Post-antibiotic effect (PAE) is the continued suppression of bacterial growth following a limited exposure to an antimicrobial agent. The presence of PAE needs consequential consideration in designing antibiotic dosage regimens. To understand the behavior of bacteria, PAE provides information on how long antibiotics are applied to the bacteria. Conventional methods of measuring PAE depend on population detection and have limitations for understanding the individual behavior of bacteria. To observe the PAE, we utilized an imaging technique with the use of microscopy. Here, we discuss the microscopic image analysis system we used to study the PAE at a single-colony level. The size and number of colonies of bacteria were measured prior to and following antibiotic removal. We could count a single colony, see the development of the settlement prior to and following exposure of antibiotics and track the colony by microscopy according to the incubation time and the image processed by our own image processing program. The PAE of antibiotics was quantified by comparing bacteria size and number based on their exposure time. In our study, we discovered that the longer exposure of antibiotics causes the bacteria to be suppressed—even after washing the antibiotics from the solution. This finding suggests that microscopic imaging detection provides a new method for understanding PAE. In addition, the behavior of the cell in response to drugs and chemicals and their removal can be examined with the use of single colony analysis.

Particle characterization with on-line imaging and neural network image analysis

We proposed a deep learning-based in situ microscopic image analysis system for detecting particles and performing size analysis in a high-density slurry, which shows great potential usage in the area of solution crystallization process. A cost-effective imaging system consisting of a flow-through cell and a 3D-printed microscopic probe was built for high-quality image acquisition. The state-of-the-art deep learning model, Mask RCNN, was used to segment the overlapping particles and classify their categories with high accuracy. A comprehensive performance evaluation of the proposed system was conducted including extrapolation to unseen particle scale, detection in different solids concentration levels, and separation of two different types of particles. Compared with the previous studies, the solids concentration detection limit was improved by five times higher in terms of particle number per frame and three times higher regarding the particle pixel fill ratio (PFR). The categorized detections successfully classified the two different particles in a mixed suspension, and the individual particle size information was extracted, which showed high consistency with the particle information. What's more, a progressive labelling strategy was employed to improve the processing efficiency and accuracy, which would enable the transfer application in solution crystallization process for various crystal species.

Identification of Extremely Similar Animal Fibers Based on Matched Filter and HOG-SVM

Identification of extremely similar animal fibers has always been one of the challenging research topics in the textile field. In this paper, an improved image-based recognition method was proposed for the identification of extremely similar animal fibers including cashmere and wool. A total of 100 groups of wool and 100 groups of cashmere fiber images were collected using the self-developed microscope image analysis system. The contrast of original fiber micro images usually was not high enough and some impurities always existed during the slicing process, so the matched filters were first applied for these images to extract the enhanced fiber binary texture, which only needs to set reasonable segment length and the threshold for different fiber images to eliminate impurities and background. Then, the high-dimensional texture features of the original color images, gray images, and the images processed by matched filter were extracted by calculating and analyzing the histogram of oriented gradient (HOG). The 200 sets of original color images, gray images, and processed images were divided into the training set and testing set according to different proportions, and the recognition expert system based on the support vector machine (SVM) could be trained and validated accordingly. The experimental results show that the recognition accuracy of the fiber images processed by matched filter was obviously improved compared with that of the other two data sets, and the recognition rate reaches the highest with 92.5%. It also proves that the proposed algorithm in this paper can classify and identify extremely similar wool and cashmere fibers more quickly and effectively compared with other texture feature extraction and identification algorithms.

In situ investigation of the effect of stretching speed and annealing conditions on the crazing of as-spun IPP fibres using Pluta polarizing interference microscope

The effect of annealing conditions and stretching speed on the crazing and fracture behaviour of thermally treated as-spun IPP fibres during stretching with constant strain rate was investigated. The study includes observations and quantifying the crazing that occurs on stretched fibres via the estimation of the areal craze density as a function of annealing duration and stretching speed. An automated two-beam polarizing light interference Pluta microscope with the aid of modified mechanical stretching device are used for this investigation. Increasing the strain rate for thermally treated samples tends to delay the craze initiation and lowers the amount of areal craze density. A technique based on microscopic image analysis system(MIAS) with suitable designed software were used to observe the general feature of a single craze and calculate its wide and length. The value of strain rate is more effective than thermal history (annealing temperature and duration) on the crazing process of IPP fibres.

Biological interface study of HA/ZrO2 graded composite in a dog lumbar vertebra bone defect model

This study compared bony fusion in autologous bone grafting with HA/ZrO2 graded composite in terms of mineral depositions, histological characteristics, and biomechanical properties of bonding interface. Twenty-four beagle dogs were established four places of bone defect in two adjacent lumbar vertebral bodies (L4 and L5) and were successively implanted with HA/ZrO2 graded composite (group A), HA/ZrO2 unilayer composite (group B), pure ZrO2 (group C), and pure HA (group D). After operation, lumbar vertebral specimens were respectively harvested per time at week 6, 12, and 16. Then, the bony fusion interface was evaluated by fluorescence microscope and computer image analysis system to measure mineral apposition rates (MAR). Histological analysis of specimen was used to determine bone bonding rates (BBR) and possible foreign body reactions associated with each groups. And interface bonding force between implant and autogenous bone was quantified with biomechanical push-out test. Compared with other groups, group A led to significantly higher MAR from week 6 to 12 (p < 0.05). Histologically, new bony tissue and hyaline cartilage were seen around the HA/ZrO2 graded composite, accompanied by mild chronic inflammation. And the BBR of HA/ZrO2 graded composite were the highest (p < 0.05), while reaching (90.3 ± 3.8) % at week 16. Moreover, the biomechanical push-out tests revealed that the maximum interface shear strength of group A was respectively (2.64 ± 0.16) MPa, (2.95 ± 0.19) MPa, and (3.45 ± 0.23) MPa at week 6, 12, and 16, which all possessed significantly statistical differences with other three groups (p < 0.05).

Reduction of glycine particle size by impinging jet crystallization

The parameters of crystallization processes determine the habit and particle size distribution of the products. A narrow particle size distribution and a small average particle size are crucial for the bioavailability of poorly water-soluble pharmacons. Thus, particle size reduction is often required during crystallization processes. Impinging jet crystallization is a method that results in a product with a reduced particle size due to the homogeneous and high degree of supersaturation at the impingement point.In this work, the applicability of the impinging jet technique as a new approach in crystallization was investigated for the antisolvent crystallization of glycine. A factorial design was applied to choose the relevant crystallization factors. The results were analysed by means of a statistical program. The particle size distribution of the crystallized products was investigated with a laser diffraction particle size analyser. The roundness and morphology were determined with the use of a light microscopic image analysis system and a scanning electron microscope. Polymorphism was characterized by differential scanning calorimetry and powder X-ray diffraction. Headspace gas chromatography was utilized to determine the residual solvent content.Impinging jet crystallization proved to reduce the particle size of glycine. The particle size distribution was appropriate, and the average particle size was an order of magnitude smaller (d(0.5)=8–35μm) than that achieved with conventional crystallization (d(0.5)=82–680μm). The polymorphic forms of the products were influenced by the solvent ratio. The quantity of residual solvent in the crystallized products was in compliance with the requirements of the International Conference on Harmonization.

The role of the organic anion transporting polypeptide OATP4A1 in immunactivation in colorectal cancer and inflammatory colon disease.

481 Background: OATP-transporter proteins, such as OATP4A1, present influence cancer progression by providing compounds (hormones, prostaglandins, cyclic nucleotides, second messenger proteins, drugs) which either inhibit or stimulate tumor cells growth. Therefore, OATP expression in cancer cells and in the stroma, i.e., the microenvironment surrounding the epithelial cells can become a critical parameter. Methods: OATP4A1 was investigated in paraffin-embedded specimens from 148 patients with colorectal cancer and 20 with diverticulitis by immunohistochemistry (IHC) on an automatic quantitative microscopic image analysis system (TissuesFaxs). With the Histoquest program, the immunoreactive score (IRS), was calculated from the degree of the staining intensity and the number of OATP4A1-positive cells. To identify OATP4A1+-cells, double-immunofluorescence staining (IF) was done with antibodies against appropriate cellular markers. Results: OATP4A1 was located in the membrane and cytosol of colon cancer cells and immune cells, while membranous OATP4A1staining was seen in normal mucosa. OATP4A1 levels were higher in cancer cells in patients without tumor recurrence for up to 5 years (NR) than in patients with an early relapse (R) having IRS of 4391±231 and 3026±373 (Mean±SEM), respectively. Highest OATP4A1 levels were observed in immune cells in the tumors of Rs (IRS, 5712 ±254, while in NRs they were lower (IRS: 3549±358; p=0.05). In both groups, OATP4A1 levels in stroma cells were low (288±54 vs. 611±82). OATP4A1 expressing immune cell subtypes in cancer and diverticulitis sections were identified as CD45+ leukocytes, CD3+ T- and CD20+ B-cells, CD68+ macrophages, CD34+precursor cells. OATP4A1 was not detectable in Conclusions: High levels of OATP4A1 in immune cells in malignant and non-malignant colon disease suggest a role of the transporter in the activation of the immune system in malignant and non-malignant colon disease. Whether OATP4A1 might be a therapeutical target has to be established.

Evaluation of removal of model particulate and oily soils from poly(ethylene terephthalate) films by microscopic image analysis

The soil removal behavior from poly(ethylene terephthalate) (PET) films was investigated using a microscopic image analysis system. Carbon black or stearic acid as a model soil was deposited onto a PET film. The PET film was cleaned in various aqueous and non-aqueous solutions by applying stirring or frequency-modulated ultrasound as a mechanical action of soil removal. The amounts of soil deposited on the PET film before and after cleaning were obtained via binary processing of microscopic images, from which the removal efficiency was calculated. Most of the carbon black was deposited on the PET film as submicron aggregates and ultrasound removed them efficiently in a short time, even for relatively smaller aggregates. The removal efficiencies with stirring were less than ca. 10% in all solutions, whereas the removal using ultrasound had high efficiencies that exceeded 80% in the surfactant-free systems. In the case of stearic acid, the removal efficiency with stirring was below 30% in the aqueous solutions, although stearic acid was removed completely in ethanol and n-decane. For ultrasonic cleaning, the removal efficiencies of stearic acid in aqueous solutions became 2-3 times as large as those with the stirring action. To improve soil release in aqueous solutions, the PET film was treated by the dry processing using an atmospheric pressure plasma jet (APPJ) equipment. The wettability and the surface free energy of the PET film were found to increase due to surface oxidation via the APPJ treatment, which resulted in enhanced removal of carbon black and stearic acid in any aqueous solutions.

DEVELOPMENT OF A PC12 CELL CULTIVATION AND MONITORING SYSTEM FOR NEURONAL-LIKE STUDY

A variety of cell lines are often used to simulate the studies associated with the cell products, genetics, cell–cell interaction, environmental interaction, intracellular flux and intracellular activity. Among these cell lines, the pheochromocytoma (PC12 for short) cell line is the one that is widely applied in in vitro study for investigating the neuronal apoptosis, neurochemistry, and neuronal differentiation. The development of an appropriate cell cultivation platform as well as the real-time image acquisition and analysis system becomes an important issue. The purpose of this paper is to develop a long-term and low-cost incubation system, including microscopic image analysis system for morphological analysis. The proposed incubation system can acquire cell image for analysis during cell cultivation. From the experimental results, the temperature of incubation system is found to be in the range of 37.3 ± 1.3°C, and the lower levels of the relative humidity vary within 89.7 ± 1.8%. The CO2 concentration is controlled at 5.29 ± 0.71%. The cell number is increased from 1.00 × 105 to 4.25 × 105 cells/ml after 48 h of culture. The cell viability test shows that this developed incubation system works well for PC12 cells cultivation; it can also acquire and segment the cell image during the cell cultivation. Besides, in the image analysis software design, the region-growing and modified blob labeling techniques are also employed to segment the PC12 cell image under varied culture conditions for later morphological and feature quantification analysis.

MAPK-activated Protein Kinase-2 (MK2)-mediated Formation and Phosphorylation-regulated Dissociation of the Signal Complex Consisting of p38, MK2, Akt, and Hsp27

The p38 MAPK and heat shock protein 27 (hsp27) form a signaling complex with serine/threonine kinase Akt and MAPK-activated protein kinase-2 (MK2), which plays an important role in controlling stress-induced apoptosis and reorganizing actin cytoskeleton. However, regulation of the complex is poorly understood. In this study, the interaction between p38 and hsp27 was visualized in single living L929 cells using fluorescence resonance energy transfer technology, while their association with Akt was examined by immunoprecipitation analysis. Under normal growth conditions, p38 kinase constitutively interacts with hsp27. When cells were exposed to H(2)O(2) or stimulated by arachidonic acid, this interaction was disrupted. However, inhibition of the activation of p38 and Akt by selective inhibitors or overexpression of the kinase-dead mutant of p38 diminished such effects. Furthermore, mutation of phosphorylation sites of hsp27 renders the interaction resistant to H(2)O(2) and arachidonic acid. It was interesting to find that the interaction disappeared in the cells from MK2-knock-out mice or the cells treated with lemptomycin B that blocks export of MK2 from nucleus to cytosol. However, MK2 is not required for the association of hsp27 with Akt. This study suggests that MK2 mediates the incorporation of p38 into the pre-existing complex of hsp27 with Akt. Phosphorylation of hsp27 finally breaks the signaling complex.

Use of Comet assay to assess DNA damage in patients infected by Helicobacter pylori: Comparisons between visual and image analyses

Studies of DNA damage in gastric epithelial cells of Helicobacter pylori ( H. pylori)-infected patients are conflicting, possibly due to different methods used for scoring DNA damage by Comet assay. Therefore, we compared the sensitivity of visual microscopic analysis (arbitrary units—scores and comets%) and image analysis system (tail moment), in the gastric epithelial cells from the antrum and corpus of 122 H. pylori-infected and 32 non-infected patients. The feasibility of cryopreserved peripheral blood lymphocytes and whole-blood cells for DNA damage biomonitoring was also investigated. In the antrum, the levels of DNA damage were significantly higher in H. pylori-infected patients with gastritis than in non-infected patients with normal mucosa, when evaluated by image analysis system, arbitrary units and comets%. In the corpus, the comets% was not sufficiently sensitive to detect the difference between H. pylori-infected patients with gastritis and non-infected patients with normal mucosa. The image analysis system was sensitive enough to detect differences between non-infected patients and H. pylori-infected patients with mild gastritis and between infected patients with moderate and severe gastritis, in both antrum and corpus, while arbitrary units and comets% were unable to detect these differences. In cryopreserved peripheral blood lymphocytes, the levels of DNA damage (tail moment) were significantly higher in H. pylori-infected patients with moderate and severe gastritis than in non-infected patients. Overall, our results indicate that the image analysis system is more sensitive and adequate to measure the levels of DNA damage in gastric epithelial cells than the other methods assayed.

Prediction of radiotherapy-induced dermatitis by comet assay in ex vivo irradiated patients’ lymphocytes

It is estimated that approximately 5–10% of patients develop Grade 2 acute dermatitis following whole breast radiotherapy as a part of breast conservative therapy for early breast cancer. The aim of the present study was to assess the predictive value of ex vivo comet assay using patients’ lymphocytes for the occurrence of radiotherapy-induced dermatitis. Among over 1,500 patients who had been treated with whole breast radiotherapy in our institute, 63 patients entered this study. Twenty-nine patients who had developed Grade 2 whole breast bright erythema and 34 control patients were carefully selected, so that the patients characteristics and the therapeutic parameters of the two groups should be evenly matched. The patients’ lymphocytes were irradiated with a dose of 12 Gy, and fixed 0 to 180 minutes after irradiation. The cells were subjected to the single cell gel alkaline electrophoresis assay (comet assay), stained with propidium iodide, and processed by a fluorescence microscopic image analysis system to measure the amount of radiation-induced DNA damage. Standardized tail moment (STM) was determined at each time point, and a time-course curve was drawn for individual patients. In most cases, STM decreased with time, representing the repair procedure of radiation-induced DNA damage. Four independent DNA damage and repair parameters were calculated from the time-course curve; initial damage (ID) defined as the STM at 0 min, residual damage (RD) defined as the STM at 180 min, repair half-time (RHT) defined as the time required to reduce the STM to 50% of the initial STM, and total repair capacity (TRC) defined as the area under the time-course curve of STM. The mean ± SE of ID in the dermatitis group and the control group was 33.0 ± 2.3 and 36.9 ± 2.2 (p = 0.22), RD was 7.3 ± 1.1 and 7.2 ± 0.9 (p = 0.94), RHT was 31.0 ± 4.8 min and 20.6 ± 2.5 min (p = 0.05), and TRC was 1860 ± 190 and 2080 ± 160 (p = 0.37), respectively. The patients in the dermatitis group showed significantly longer RHT, while there was no correlation between the other parameters and the occurrence of dermatitis. The results suggested that RHT, a parameter representing DNA repair velocity in ex vivo comet assay, may be a candidate for the radiation dermatitis predictor in patients receiving whole breast radiotherapy. Further evaluation of this assay in a prospective setting is indicated

Waxy Corn Starch: A Potent Cofiller in Pellets Produced by Extrusion–Spheronization

The purpose of this study was to assess the usefulness of waxy corn (maize) starch as a cofiller and diluent in pellets produced by aqueous extrusion–spheronization. Waxy corn starch was combined with microcrystalline cellulose (MCC) in the range of 20–50% of the entire composition. Pellets containing ordinary corn starch or lactose with MCC were used as reference. The shape of pellets was characterized using an optical microscopic image analysis system. The surface and cross-sectional structure were investigated by means of scanning electron microscopy (SEM). The replacement of ordinary corn starch by waxy corn starch made it possible to increase the amount of starch from 20 to 40%. The pellets containing 50% waxy corn starch were of poorer quality but superior to those containing 30% corn starch. The surface structure became slightly more irregular with respect to the amount of either starch, and a cavity was formed inside the pellet during the spheronization. The origin of starch did not affect the surface structure of the pellets. Waxy corn starch is a potential cofiller: the amount of MCC can be reduced in pellets produced by extrusion–spheronization by using waxy corn starch as a cofiller. This enables the reduction of the manufacturing cost of pellets with low drug load.

CASTRATION INDUCES ACUTE VASOCONSTRICTION OF BLOOD VESSELS IN THE RAT PROSTATE CONCOMITANT WITH A REDUCTION OF PROSTATIC NITRIC OXIDE SYNTHASE ACTIVITY

Previous studies demonstrating a rapid and drastic reduction of blood flow to the rat prostate gland resulting from castration caused us to consider the influence of castration on the state of vascular constriction and on the activity of the vascular tone-regulating factors (nitric oxide synthase and cyclic GMP) in the rat prostate. Sections of ventral prostate glands obtained from intact and castrated rats were analyzed for the mean areas within smooth muscle-coated blood vessels using a computerized microscopic image analysis system. Nitric oxide synthase (NOS) levels were measured in prostatic extracts from unoperated or castrated rats using an enzyme assay system that measures conversion of 3H-L-arginine to citruline. Cyclic GMP levels were measured in prostatic extracts from unoperated or castrated rats using a competitive radioimmunoassay system. The mean area within ventral prostate smooth muscle-coated blood vessels was reduced 39% at 24 hours after castration (p = 0.039) and 47.7% at 48 hours after castration (p = 0.039). NOS activity measured in prostatic extracts was reduced 38% at 24 hours (p = 0.0012) and 51.6% at 36 hours after castration (p = 0.0001) compared with the control group of noncastrated rats. Finally, prostatic cGMP levels were reduced 55.8% (p = 0.0018) at 36 hours after castration when compared with controls rats. Within 24 hours after castration, the lumenal areas of smooth muscle-coated blood vessels in the rat prostate gland were found to be significantly reduced. This vasoconstriction was associated with a significant reduction of prostatic NOS activity as well as a reduction in the prostatic levels of the NOS co-factor, cGMP. Thus, acute vasoconstriction is a prominent early event associated with rat prostate regression in response to castration and likely contributes to the regression of the tissue.