Contents Of Tubes Research Articles

A Self‐Consistent Model of Radial Transport in the Magnetodisks of Gas Giants Including Interhemispheric Asymmetries

AbstractOutward transport of plasma in the inner and middle magnetospheres of gas giants results from an interplay between mass loading from the inner dominant mass sources (volcanic moons), flux tube interchange in the centrifugally unstable magnetospheric plasma disk, turbulent heating of the plasma, and coupling between the equatorial plasma and the planetary upper atmosphere through magnetic field‐aligned current loops and/or Alfvén waves. We present a new analytical formalism describing large scale transport in gas giant systems, combining two historical approaches: radial diffusion of mass and energy through flux tube interchange, and angular momentum transport through corotation enforcement. Under the hypotheses of axisymmetry, steady‐state, and multi‐fluid plasma, we provide transport equations for total contents of flux tubes. They feature new transport parameters accounting for the latitudinal extent of the disk, and self‐consistently include field‐aligned potential drops in the magnetosphere‐ionosphere coupling. Our general formalism has a wealth of applications, two of which are presented, corresponding to the cases of the two gas giants: the effect of interhemispheric asymmetries in the resistive and magnetic properties between the northern and southern ionospheres on the transport of angular momentum at Jupiter, and the influence of the plasma disk thickness on transport at Saturn. We apply our formalism to derive ionospheric parameters and reproduce the Juno and Cassini data. Further work will allow for more complete numerical solutions of our equations, with the aim of capturing the broad complexity of fast rotating magnetospheric systems which can be found inside and outside the Solar System.

Automated system for analysing the process of plant micropropagation

The article describes the development and implementation of an automated system for analysing the process of plant micropropagation in a biotechnology laboratory. The system was developed within the framework of the federal targeted program and tested at the largest planting material producer in the Chechen Republic. The implementation of digital technologies allowed the enterprise to control the process of micropropagation, accounting for products, measure the parameters of objects, determine the viability of plants, control the contamination of the nutrient medium, identify varieties and increase the survival rate of planting material up to 70%. The robotic system consists of a mechanical robotic arm that moves along a rack with test tubes and a camera to capture an image of the object, while computer vision analyses the contents of the test tubes. The software of the automated system contains a database of all studied samples of nutrient media, on the basis of which it is possible to analyse the resistance of a culture to various factors. The results of the study show the effectiveness of the developed system for accelerating and increasing the accuracy of the plant breeding process.

The Effect and Mechanism of External Use Ulcer Powder on Diabetic Mice.

Objective Through the preparation of the diabetic mice skin ulcer model, we investigated the effect of Mongolian medicine external ulcer powder (WYK) on the treatment of diabetic skin ulcers and the expression of angiogenesis-related factors such as vascular endothelial growth factor (VEGF) and extracellular regulated protein kinases (ERK).Methods Thirty male clean Kunming mice were randomly divided into normal control group (group C), diabetic control group (group HC), and diabetic topical ulcer powder group (group HW). After successful modeling in the HC group and the HW group, the rats in the HW group were given external ulcer powder, which was applied to the back of the mice once a day. In addition, the rats in group C and group HC were treated with gentamicin injection external application once a day. The mice were sacrificed on the 3rd, the sixth, and the ninth day of dosing, and samples were taken. The adopted methods included protein immunoblotting (western blot) and reverse transcription-polymerase chain reaction (RT-PCR). The expression differences of angiogenesis-related factors such as VEGF and ERK in the repair process were detected. SPSS 13 software was used to analyze the results of angiogenesis-related factors VEGF and ERK.ResultsComparison of VEGF and ERK ContentsThe serum VEGF content of mice in the HC group was significantly lower than that in the C group on days 3, 6, and 9 (p <0.05). The VEGF content in the HW group was significantly higher than that in the HC group (p <0.05). The content of ERK in serum was basically consistent with that of VEGF. The results of the western blot assay were consistent with those of the RT-PCR assay.Conclusion WYK can effectively promote the healing of skin ulcer wounds in diabetic mice, accelerate the proliferation of granulation tissue, enrich the contents of capillary blood tubes and collagen fibers, and increase the microvascular content. WYK can improve the expression level of VEGF and ERK in the serum of mice and advance the peak value of protein expression.

Effect of nanoparticles loading on free vibration response of epoxy and filament winding basalt/epoxy and E-glass/epoxy composite tubes: experimental, analytical and numerical investigations

In recent times, basalt fiber reinforced polymer (BFRP) nanocomposites is being increasingly used in aerospace applications such as wing and fuselage structures of the aircraft and outer casings of the rocket, automobile engine drive shafts and fuel tanks in the oil and gas industries, which fills the gap between carbon and E-glass fiber reinforced polymer nanocomposites. These structures are subjected to vibrations and exposed to different temperatures in various places during their service life. However, the comparison of vibration response of silica particles reinforced basalt/epoxy and glass/epoxy nanocomposite tubes in all three approaches, namely, experimental, analytical and numerical (Finite Element Modeling), have not found elsewhere. Analytical and numerical approaches minimize time, manpower and cost. Therefore, investigating the vibration response of different weight contents of these FRP nanocomposite tubes is novel and essential. Hence, in this study, the vibration response of silica nanoparticles reinforced epoxy, basalt/epoxy and E-glass/epoxy composites with different weight contents (0, 0.5, 1 and 1.5%) were investigated. The vibration tests were performed at three different boundary conditions such as cantilever, simply supported and fixed-fixed. The first three modes of vibration were considered for analysis. Besides, the heat deflection temperature and the hardness properties were also studied. The results indicate that the natural frequencies were higher for the fixed-fixed case and the damping parameters were higher for the simply supported case. Vibration properties, heat deflection temperature and hardness values were found to be higher in fiber-reinforced nanocomposites than those of epoxy nanocomposites. The data presented in this study will be useful to generate the numerical models for the ground vibration test (GVT).

Infections of the genital tract in women with verified laparoscopy of the pathology of the fallopian tubes and normal laparoscopic results

Introduction. Pipe and peritoneal factors are important causes of infertility and inflammatory diseases of the pelvic organs (PID). It is well known that Neisseria gonorrhoeae and Chlamydia trachomatis are etiologic agents of pelvic inflammation leading to infertility. There is a very limited number of publications about which representatives of sexually transmitted infections (STIs) or other microorganisms can be found in the fallopian tubes during reconstructive plastic surgery. Knowledge in this area is necessary for the proper selection of antibiotic therapy during and after operations. The purpose of our study is to determine the microbial landscape of the contents of the fallopian tubes in infertile patients with a tubal peritoneal infertility factor diagnosed during laparoscopy and normal uterine tubes. Materials and methods. 22 women with infertility were included in the study. 12 of them (the main group) had tubal peritoneal pathology, 10 women had no pathology of the fallopian tubes (control group). The average age of patients in the first group was 25 years (20-29), in the control group - 31 years (20-36). For all women, laparoscopy was part of the infertility survey. In the 1 st group, the changes in the fallopian tubes according to the type of fibrosis, hydrosalpinx or adhesions in the region of the periampulal or fimbrial part were identified. During laparoscopy, the fallopian tubes were washed with 2-4 ml of saline immediately after laparoscopic and laparoscopic instruments. Through the lateral trocar, the material was taken from the fallopian tubes using a bacteriological loop to perform bacteriological inoculation. Identification of the DNA of the pathogens was carried out by the polymerase chain reaction method according to the instructions. Identification and sensitivity determination of the isolated cultures was performed using an automatic bacteriological analyzer Vitek 2 Compact 30. Results. In all women without an identification of STIs and PID in the history and absence of abnormalities of the fallopian tubes in laparoscopy (control group), we did not find any microorganisms in the fallopian tubes. We did not detect C. trachomatis, N. gonorrhoeae or Trichomonas vaginalis in the fallopian tubes. However, we found twice Ureaplasma urealyticum in the fallopian tubes (16.7%), while in the control group this microorganism was also detected once. An important feature of salpingitis is extensive tissue remodeling, leading to chronic effects, such as scarring and obstruction, during which STIs and other microorganisms are eliminated by the immune system. In this study, we identified twice in the fallopian tubes of U. urealyticum. Perhaps U. urealyticum persists after antibiotic therapy and selective elimination of the main pathogens, since certain antibiotics affect the cell wall that is absent in this microorganism.

Vortex-Assisted Modified Dispersive Liquid-Liquid Microextraction of Trace Levels of Cadmium in Surface Water and Groundwater Samples of Tharparkar, Pakistan, Optimized by Multivariate Technique.

A simple vortex-assisted modified dispersive liquid-liquid microextraction procedure is proposed for the enrichment of cadmium (Cd+2) in surface (stored rainwater) and groundwater of the Tharparkar district in Pakistan, before analysis by flame atomic absorption spectrometry. Ammonium pyrrolidinedithiocarbamate was used as a ligand to make a hydrophobic complex of Cd+2, which was extracted in an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate), and the nonionic surfactant Triton X-114 was applied as a dispersing medium. The contents of tubes were shaken for different time intervals on a vortex mixer to enhance extraction efficiency. A multivariate strategy was used to simultaneously evaluate seven factors including, concentration of the complexing reagent, pH, amounts of ionic liquid and Triton X-114, vortex shaking time, centrifugation time and extracting solution for their influence on the percentage recovery of the analyte. The important variables were further optimized by central composite design. The preconcentration factor and LOD were observed as 76.9 and 0.048 µg/L, respectively. The Certified Reference Material SRM1643e was used to check the validity of the developed method, and the RSD was found to be 4.02%. The proposed technique was successfully applied for the enrichment of Cd+2 in groundwater and surface water samples from the southeastern part of Pakistan. The observed results revealed that the concentration of Cd+2 in groundwater was higher than the World Health Organization recommended value of 3 µg/L for drinking water. For adults weighing approximately 60 kg, consumption of groundwater for drinking and other domestic purposes would provide levels of Cd+2 that are 2- to 3-fold higher than the provisional maximum tolerable daily intake.

Effect of photoactivation on the reduction of composite resin contamination

Composite resins are predominantly marketed in developing countries in tube form, and the contents of the tube may be used in numerous procedures for different patients. This represents a problem because of the risk of cross-contamination. This study aimed to evaluate contamination in vitro of the internal contents of composite resin tubes in the dental clinics of a higher-education institution, as well as the effect of photoactivation on the level of contamination. Twenty-five tubes containing composite resin were randomly chosen (by lottery). From each tube, two samples of approximately 2 mm of composite resin were removed, and then one sample, but not the other, was photoactivated. These samples were plated on Brain-Heart Infusion (BHI), Sabouraud and MacConkey agars, and the plates were incubated at 37°C for 24-48 h. Colony counting and Gram staining were performed for subsequent microscopic identification of fungi and bacteria. The non-photoactivated composite resin group presented significantly higher microbial contamination in relation to the photoactivated composite resin group. The photoactivation of camphorquinone present in composite resin produces reactive oxygen species, which might promote cell death of contaminant microorganisms. Thus, although the same tube of composite resin may be used for a number of different patients in the dental clinics of developing countries, the photoactivation process potentially reduces the risk of cross-contamination.

CHANGES IN THE STRUCTURE OF SURGICAL INFECTIOUS MATTER IN PATIENTS WITH DIABETES MELLITUS, DEPENDING ON THEIR TREATMENT STRATEGY

Objective – to study the dynamics of changes in the structure of surgical infectious matter and their sensitivity to antibiotics in patients with diabetes mellitus (DM), depending on the strategy of the surgical treatment. Materials and methods. The subject of this study were clinical samples (biopsy material of the wounds, tissue-prints from the wounds surface, wound fluid, blood, the contents of the drainage tubes, etc.) of 268 patients treated at the department of wounds and wound infections of the A.V. Vishnevsky Surgery Institute in 2012–2015. with various nosologic forms of acute and persistent purulent surgical infections (diabetic foot syndrome, paraendoprosthetic infection after surgery on the arteries of the lower extremities, chronic postoperative osteomyelitis of the sternum and the ribs, chronic posttraumatic osteomyelitis of long bones, chronic ulcers of venous etiology, necrotic wounds of various etiologies). Objective – to study the dynamics of changes in the structure of surgical infectious matter and their sensitivity to antibiotics in patients with diabetes mellitus (DM), depending on the strategy of the surgical treatment. Materials and methods. The subject of this study were clinical samples (biopsy material of the wounds, tissue-prints from the wounds surface, wound fluid, blood, the contents of the drainage tubes, etc.) of 268 patients treated at the department of wounds and wound infections of the A.V. Vishnevsky Surgery Institute in 2012–2015. with various nosologic forms of acute and persistent purulent surgical infections (diabetic foot syndrome, paraendoprosthetic infection after surgery on the arteries of the lower extremities, chronic postoperative osteomyelitis of the sternum and the ribs, chronic posttraumatic osteomyelitis of long bones, chronic ulcers of venous etiology, necrotic wounds of various etiologies).

Comparative evaluation of antibacterial efficacy of plants traditionally used as antidiarrheal against enteropathogenic Escherichia coli

The study was conducted to investigate the antibacterial efficacy against enteropathogenic E. coli of plants commonly used to treat calf-diarrhoea. Methanolic extracts of six plants (Aegle marmelos, Curcuma longa, Dalbergia sissoo, Mangifera indica, Psidium guajava and Punica granatum) were screened for their antibacterial property against enteropathogenic E. coli by standard disc diffusion method. Minimum inhibitory concentration (MIC) and of the extract exhibiting highest antibacterial activity was estimated by broth dilution method and minimum bactericidal concentration (MBC) was measured by streaking the contents of MIC tubes on nutrient agar plates. Among the six extracts tested, only extracts of Curcuma longa, Psidium guajava and Punica granatum exhibited antibacterial activity against E. coli. Out of these three, Punica granatum extract was found to be most effective with a mean inhibition zone of 14.67±0.577 mm followed by Psidium guajava (9.67±0.577 mm) and Curcuma longa (8.67±0.577 mm), produced by the disc containing 8.00 mg of respective extract. Minimum inhibitory concentration and minimum bactericidal concentration of the Punica granatum extract were estimated to be 02.00 mg/mL and 03.00 mg/mL respectively. These findings suggest that methanolic extracts of Curcuma longa, Psidium guajava and Punica granatum possess antibacterial activity against enteropathogenic E.coli

Circadian variation in midgut digestive enzyme activity in cotton bollworm Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

In this study, total protease, α-amylase and lipase activity of cotton bollworm were studied under four different photoperiod regimes. Insects were reared from first larval stages on artificial diet under controlled conditions (26±2°C temperature, 60±5 % RH) in incubators under four photoperiod regimes, including light (24: 0), dark (0: 24), 12:12h (L:D) and 16:8h (L:D). Sixth larval stage was used for enzyme assays and after dissection, alimentary canal of larva was separated from body and transferred to 1.5ml micro tubes containing 1ml cold glycine–NaOH, pH10 buffer. Contents of tubes were homogenized and centrifuged, and the supernatants were used as enzyme source. Sampling was carried out for 24h at 3h intervals. The enzyme activity (α-amylase and lipase) was measured using diagnostic kit and azocaseinolytic assay carried out for total protease assays. Results indicated that photoperiod regimes changed enzyme activity profile, and digestive enzyme activity was significantly changed during the diel period. Alpha-amylase activity increased from 9:00h to 15:00h in all the studied photoperiods. Alpha-amylase and lipase activity in light photoperiod was more than the dark one, but total protease activity increased in dark photoperiod especially from 12:00 to 18:00h, compared with the other photoperiods. A slight increase in digestive enzyme activity was observed at 3:00h in light and dark photoperiods.

Secretions from the female gametophyte and their role in spermatozoid induction in Cycas revoluta

In cycads, spermatozoids are released from pollen tubes and swim in fluid toward the archegonia. The source of this fluid was examined using Cycas revoluta Thunb. ovules placed in culture. Dissected female gametophytes just before fertilization produced copious fluid on their upper surface. The fluid first appeared around the archegonial chamber and then on the inside of the archegonial chamber. When this fluid was applied to dry turgid pollen tubes, they discharged spermatozoids 12 h later. The archegonial neck appeared as two semi-spherical swellings, whereas the four neck cells later became visible and they separated in a schizogenous manner. Many globose particles appear on the top of the archegonial neck cells when the fluid is present. The contents of pollen tubes, spermatozoids and surrounding liquid intermingle with the secreted fluid. The female gametophyte differs in ultrastructure during the stages before and after fluid secretion, the latter showing changes suggestive of fluid secretion from the female gametophyte.

Is Phlebotomy Part of the Dark Side in the Clinical Laboratory Struggle for Quality?

Blood collection is a critical part of the preanalytical phase of laboratory testing. Only a few procedures are evaluable for detecting errors in this non-automatic activity. Information about potential sources of error is frequently absent from quality-control procedures and training materials. To evaluate the performance of phlebotomists and to identify the major sources of errors during diagnostic blood collection. We evaluated the performance of 3 phlebotomists each from 10 laboratories regarding tourniquet time, request for fist clenching, excessive friction during skin cleaning, sequence of vacuum-tube usage, and mixing of tube contents after specimen collection. The total number of these laboratories represented an equal number of private (ie, owned by private parties) and public (ie, administration by government organizations) settings. An error rate of greater than 60% was observed in the performance of procedures we examined, and the error rate was not significantly different between public and private settings other than more adequate mixing of the contents of primary collection tubes in private facilities. Most facilities did not achieve adequate quality standards in phlebotomy. In procedural manuals, training materials and practices for phlebotomists, greater emphasis should be placed on presenting information on possible sources of error and on the correct implementation of procedures that ensure the quality of diagnostic blood specimens collected for laboratory analysis.

Insoluble Aggregates and Protease-resistant Conformers of Prion Protein in Uninfected Human Brains

Aggregated prion protein (PrPSc), which is detergent-insoluble and partially proteinase K (PK)-resistant, constitutes the major component of infectious prions that cause a group of transmissible spongiform encephalopathies in animals and humans. PrPSc derives from a detergent-soluble and PK-sensitive cellular prion protein (PrPC) through an alpha-helix to beta-sheet transition. This transition confers on the PrPSc molecule unique physicochemical and biological properties, including insolubility in nondenaturing detergents, an enhanced tendency to form aggregates, resistance to PK digestion, and infectivity, which together are regarded as the basis for distinguishing PrPSc from PrPC. Here we demonstrate, using sedimentation and size exclusion chromatography, that small amounts of detergent-insoluble PrP aggregates are present in uninfected human brains. Moreover, PK-resistant PrP core fragments are detectable following PK treatment. This is the first study that provides experimental evidence supporting the hypothesis that there might be silent prions lying dormant in normal human brains.

Receptor Activity-modifying Protein (RAMP) Isoform-specific Regulation of Adrenomedullin Receptor Trafficking by NHERF-1

Receptor activity-modifying proteins (RAMPs 1-3) are single transmembrane accessory proteins critical to various G-protein coupled receptors for plasma membrane expression and receptor phenotype. A functional receptor for the vasodilatory ligand, adrenomedullin (AM), is comprised of RAMP2 or RAMP3 and calcitonin receptor-like receptor (CRLR). It is now known that RAMP3 protein-protein interactions regulate the recycling of the AM2 receptor. The major aim of this study was to identify other interaction partners of RAMP3 and determine their role in CRLR-RAMP3 trafficking. Trafficking of G-protein-coupled receptors has been shown to be regulated by the Na+/H+ exchanger regulatory factor-1 (NHERF-1), an adaptor protein containing two tandem PSD-95/Discs-large/ZO-1 homology (PDZ) domains. In HEK 293T cells expressing the AM2 receptor, the complex undergoes agonist-induced desensitization and internalization. However, in the presence of NHERF-1, although the AM receptor (CRLR/RAMP3) undergoes desensitization, the internalization of the receptor complex is blocked. Overlay assays and mutational analysis indicated that RAMP3 and NHERF-1 interact via a PDZ type I domain on NHERF-1. The internalization of the CRLR-RAMP complex was not affected by NHERF-1 when CRLR was co-expressed with RAMP1 or RAMP2. Mutation of the ezrin/radixin/moesin (ERM) domain on NHERF-1 indicated that NHERF-1 inhibits CRLR/RAMP3 complex internalization by tethering the complex to the actin cytoskeleton. When examined in a primary culture of human proximal tubule cells endogenously expressing the CRLR-RAMP3 complex and NHERF-1, the CRLR-RAMP complex desensitizes but is unable to internalize upon agonist stimulation. Knock-down of either RAMP3 or NHERF-1 by RNA interference technology enabled agonist-induced internalization of the CRLR-RAMP complex. These results, using both endogenous and overexpressed cellular models, indicate a novel function for NHERF-1 and RAMP3 in the internalization of the AM receptor and suggest additional regulatory mechanisms for receptor trafficking.

Novel Function for Receptor Activity-modifying Proteins (RAMPs) in Post-endocytic Receptor Trafficking

RAMPs (1-3) are single transmembrane accessory proteins crucial for plasma membrane expression, which also determine receptor phenotype of various G-protein-coupled receptors. For example, adrenomedullin receptors are comprised of RAMP2 or RAMP3 (AM1R and AM2R, respectively) and calcitonin receptor-like receptor (CRLR), while a CRLR heterodimer with RAMP1 yields a calcitonin gene-related peptide receptor. The major aim of this study was to determine the role of RAMPs in receptor trafficking. We hypothesized that a PDZ type I domain present in the C terminus of RAMP3, but not in RAMP1 or RAMP2, leads to protein-protein interactions that determine receptor trafficking. Employing adenylate cyclase assays, radioligand binding, and immunofluorescence microscopy, we observed that in HEK293 cells the CRLR-RAMP complex undergoes agonist-stimulated desensitization and internalization and fails to resensitize (i.e. degradation of the receptor complex). Co-expression of N-ethylmaleimide-sensitive factor (NSF) with the CRLR-RAMP3 complex, but not CRLR-RAMP1 or CRLR-RAMP2 complex, altered receptor trafficking to a recycling pathway. Mutational analysis of RAMP3, by deletion and point mutations, indicated that the PDZ motif of RAMP3 interacts with NSF to cause the change in trafficking. The role of RAMP3 and NSF in AM2R recycling was confirmed in rat mesangial cells, where RNA interference with RAMP3 and pharmacological inhibition of NSF both resulted in a lack of receptor resensitization/recycling after agonist-stimulated desensitization. These findings provide the first functional difference between the AM1R and AM2R at the level of post-endocytic receptor trafficking. These results indicate a novel function for RAMP3 in the post-endocytic sorting of the AM-R and suggest a broader regulatory role for RAMPs in receptor trafficking.

Nitric oxide decreases IGF-1 receptor function in vitro; glutathione depletion enhances this effect in vivo

Insulin-like growth factor-1 (IGF) helps maintain healthy articular cartilage; however, arthritic cartilage becomes less responsive to the anabolic actions of IGF. We previously showed that high concentrations of nitric oxide (NO) decrease IGF receptor tyrosine phosphorylation and response to IGF in intact chondrocytes. The current studies evaluate direct effects of NO on IGF receptor kinase (IGF-RK) in vitro. NO from S-nitroso-N-acetyl-d,l-penicillamine (SNAP) or 1-hydroxy-2-oxo-3-(N-3-methyl-aminopropyl)-3-methyl-1-triazene (NOC-7) inhibits IGF-RK auto- and substrate phosphorylation in a dose and time dependent manner. There is a linear correlation between inhibition of auto- and substrate phosphorylation (r(2)=0.98). Increasing either dithiothreitol or reduced glutathione (GSH) content of the phosphorylation buffer to protect thiol groups blocks NO inhibition of IGF-RK substrate phosphorylation. Increased S-nitrosylation of cysteines in IGF-RK after exposure to SNAP suggests that NO may react with sulfhydryl groups, form S-nitrosothiols, which may result in functional modifications. NO blockade of IGF-1 stimulated proteoglycan synthesis in intact cells is enhanced when chondrocyte glutathione is depleted. The in vitro system shows that there can be direct effects of NO on IGF-RK that modify receptor function; the intact cell studies suggest that the mechanisms identified in vitro may be important in intact chondrocyte insensitivity to IGF-1 in cells exposed to NO.

Interference caused by the contents of serum separator tubes in the Vitros CRP assay.

We have observed discrepancies between C-reactive protein (CRP) measured in serum prepared from a serum separator tube (SST) and that obtained from a plain tube, when using the Vitros CRP assay. Our study aimed at elucidating the cause of these discrepancies. Eighty-seven specimens from hospitalized patients with various types of inflammatory disease were analysed using a fixed-point immuno-rate method on a Vitros CRP slide. The serum was prepared simultaneously in both vacuum and SSTs. We also performed mixing tests by adding 47 samples of serum prepared from plain tubes to SSTs and incubating for 15 min before CRP analysis. Lower values of CRP were found in serum prepared from plain tubes than in serum from SSTs. Addition of serum prepared from plain tubes to SSTs and incubating for 15 min increased the CRP values significantly. The ratio of CRP measured in serum prepared from plain tubes and from SSTs did not differ significantly from the ratio obtained when serum was prepared in a plain tube then added to an SST. We propose that SSTs can adsorb some macromolecules that form complexes with CRP. The addition of SST gel to serum results in the release of CRP molecules from these complexes, which enhances the antigen-antibody reaction on the Vitros CRP slide and increases the measured CRP concentrations.

Nonlethal Methods of Examining Fish Stomach Contents

Several nonlethal methods have been developed to determine the stomach contents of fish, including gastroscopes, tubes, stomach suction, stomach flushing, emetics, forceps, and chronic fistulas. By reviewing the literature on this subject, we found that the effectiveness (ability to remove all stomach contents) of the different methods depends on size, age, species of fish, and the size of the food items in the stomach. Overall, various methods of stomach flushing were the most effective method of recovering stomach items from a variety of fishes. Mechanized pressure appeared to be the most efficient method of stomach flushing for most large fishes. The use of syringes allowed stomach flushing to be performed on most young and small fishes. The use of tubes and stomach suctions, much simpler and less expensive methods than stomach flushing, were nearly as effective for some fishes such as black bass (Micropterus spp.) and salmonids.

Peripheral nerve regeneration in a silicone tube: effect of collagen sponge prosthesis, laminin, and pyrimidine compound administration.

Regeneration of transected peripheral nerve with a 10-mm gap encased in a silicone tube was evaluated in the presence of collagen sponge with or without laminin, or with systemic administration of a pyrimidine compound, MS-818. The sciatic nerve of 20 adult rats was transected and the proximal and distal nerve stumps were fixed in a silicone tube. The lumen of the silicone tube was empty, or filled with a collagen sponge alone or with a laminin-soaked collagen sponge. Also, a pyrimidine compound was injected intraperitoneally after implantation of the empty silicone tube. Three weeks later, the contents of the silicone tubes were processed for histological examination of regenerated nerve fibers. Other animals were observed 6, 12, and 18 months after surgery to examine the long-term effects of the collagen sponge on nerve regeneration. All animals had regenerated tissue within the tube 3 weeks after nerve transection. The diameter of the tissue decreased toward the distal stump in the empty tube, but was the same throughout the full length in the collagen sponge-containing tube. Immunohistochemical studies revealed that the nerve fibers extended beyond the midline of the regenerated tissue in animals treated with a laminin-containing collagen sponge or receiving a pyrimidine compound. Long-term observation showed the regenerated nerve was thick as the proximal stump and many neurofilament- and peripheral myelin-positive fibers were observed around the collagen sponge. Collagen sponge assists the progress of regenerated tissues in silicone tubes, and laminin-containing prostheses and administration of a pyrimidine compound enhance peripheral nerve regeneration.

Kinetics of hydration and functional specific gravity of fibrous feed by-products.

Five studies were conducted to evaluate the kinetics of digestion, hydration, and functional specific gravity (FSG) of various feed by-products (FBP) in vitro. The water-holding capacity (WHC) of alfalfa and orchardgrass (1.428 and 1.005 g/g of insoluble DM [IDM], respectively) was higher (P < .05) than the WHC of FBP, which ranged from .175 for distillers grains to .481 g/g of IDM for brewers grains pellets. Rate of hydration was the highest in brewers grains pellets and beet pulp (.215 and .252 min-1, respectively), whereas the lowest hydration rates were observed in orchardgrass, corn cob pellets, and soyhulls (.055 to .066 min-1). Loss of associated gasses from feed particles fermented in vitro increased (P < .05) their FSG when the contents of incubation tubes were transferred to pycnometers, compared with that when the incubation was carried out directly in the pycnometers (1.17 vs 1.13) to determine their FSG. Gas produced during fermentation delayed the increase in the FSG of all sources of brewers grains and beet pulp, corn gluten feed, distillers grains, orchardgrass, alfalfa, and wheat middlings but not of corn cob pellets, cottonseed hulls, and soyhulls. Averaged across hours of incubation, the FSG of FBP (except beet pulp) was either higher (P < .05) or tended to be higher than that of alfalfa and orchardgrass. Particle size of FBP did not influence FSG during fermentation in vitro. The WHC and FSG of feeds may be helpful in predicting the rate of passage of feeds through the rumen.