scholarly journals HIGH-RESOLUTION RADIOAUTOGRAPHY OF GALACTOSE-3H ACCUMULATION IN RINGS OF HAMSTER INTESTINE

1967 ◽  
Vol 35 (3) ◽  
pp. 585-604 ◽  
Author(s):  
Charles E. Stirling ◽  
William B. Kinter
Keyword(s):  
Lamina Propria ◽  
Brush Border ◽  
Technical Problem ◽  
Water Soluble ◽  
Cell Cytoplasm ◽  
The Past ◽  
Columnar Cells ◽  
Transcellular Diffusion ◽  
Galactose Content

Radioautography of water-soluble substances has posed a major technical problem for the past decade. Utilizing silicone-impregnated plastic sections of frozen-dried tissue, a quantitative method was developed for studying distribution of 3H-labeled galactose, mannitol, and phlorizin. The content of a 2-µ band may be measured with an accuracy of ±20% by light microscopy; radioautographs may also be prepared for the electron microscope. Results with intestinal tissue incubated 1–10 min in vitro and, then, frozen rapidly indicate that the first step in galactose absorption is uphill transport into the brush border of the columnar epithelium. Correction of galactose content for the mannitol space in the brush border suggests that the sugar pump is located at the surface of the microvilli. Further evidence for the surface locus of the glucose-galactose pump was obtained with phlorizin (next paper, reference 40). The galactose content of columnar cell cytoplasm always equalled that of microvilli and no transcellular diffusion gradient could be detected; during the first minutes of incubation, however, a gradient did exist between nucleoplasm and cytoplasm. Downhill exit of galactose from columnar cells may have proceeded either directly across basal membranes to adjacent lamina propria or indirectly via open intercellular spaces. Lastly, even in the absence of muscularis, the connective tissue of the lamina propria constituted enough of a diffusion barrier so that it served as a secondary accumulating compartment for galactose under present in vitro conditions.

Hand-made cloning approach: potentials and limitations

2005 ◽  
Vol 17 (2) ◽  
pp. 97 ◽  
Author(s):  
G. Vajta ◽  
P. M. Kragh ◽  
N. R. Mtango ◽  
H. Callesen
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Technical Problem ◽  
Domestic Animals ◽  
Widespread Application ◽  
The Past ◽  
The Common ◽  
Biological Problem

Two major drawbacks hamper the advancement of somatic cell nuclear transfer in domestic animals. The first is a biological problem that has been studied extensively by many scientists and from many viewpoints, including the cell, molecular and developmental biology, morphology, biochemistry and tissue culture. The second is a technical problem that may be responsible for 50% or more of quantitative and/or qualitative failures of routine cloning experiments and is partially the result of the demanding and complicated procedure. However, even the relatively rare documented efforts focusing on technique are usually restricted to details and accept the principles of the micromanipulator-based approach, with its inherent limitations. Over the past decade, a small alternative group of procedures, called hand-made cloning (HMC), has emerged that has the common feature of removal of the zona pellucida prior to enucleation and fusion, resulting in a limited (or no) requirement for micromanipulators. The benefits of HMC are low equipment costs, a simple and rapid procedure and an in vitro efficiency comparable with or higher than that of traditional nuclear transfer. Embryos created by the zona-free techniques can be cryopreserved and, although data are still sparse, are capable of establishing pregnancies and resulting in the birth of calves. Hand-made cloning may also open the way to partial or full automation of somatic cell nuclear transfer. Consequently, the zona- and micromanipulator-free approach may become a useful alternative to traditional cloning, either in special situations or generally for the standardisation and widespread application of somatic cell nuclear transfer.

scholarly journals α-Aminoisobutyric Acid Transport in the Midgut of Two Lepidopteran Larvae

1984 ◽  
Vol 108 (1) ◽  
pp. 329-339
Author(s):  
V. F. SACCHI ◽  
G. M. HANOZET ◽  
B. GIORDANA
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Membrane Vesicles ◽  
Intracellular Accumulation ◽  
Aminoisobutyric Acid ◽  
Lepidopteran Larvae ◽  
The Relationship ◽  
Columnar Cells ◽  
Low K

1. A net absorption of α-aminoisobutyric acid (AIB) takes place in vitro in the midgut of two lepidopteran larvae, Philosamia cynthia Drury and Bombyx mori L. 2. InP. cynthia the midgut epithelium accumulates AIB from the lumen, while in the same conditions AIB accumulation is not observed in B. mori midgut cells. 3. In P. cynthia, when the lumen is bathed with a low K solution, the net absorption of AIB is reduced and the intracellular accumulation from the lumen is abolished. 4. Brush border membrane vesicles, prepared from the midgut of both species, show a transient K-dependent concentrative uptake of AIB. 5. The relationship between AIB uptake and AIB concentration in the presence of a transmembrane K gradient was studied in B. mori vesicles and the kinetic constants were calculated. 6. These results confirm that there is a K-amino acid co-transport system on the brush border of columnar cells in the midgut of both larvae.

scholarly journals HIGH-RESOLUTION RADIOAUTOGRAPHY OF PHLORIZIN-3H IN RINGS OF HAMSTER INTESTINE

1967 ◽  
Vol 35 (3) ◽  
pp. 605-618 ◽  
Author(s):  
Charles E. Stirling
Keyword(s):  
Epithelial Cell ◽  
Lamina Propria ◽  
Langmuir Adsorption Isotherm ◽  
Cell Compartment ◽  
Langmuir Adsorption ◽  
Half Saturation Constant ◽  
Cell Accumulation ◽  
Freeze Dried ◽  
Galactose Content

Quantitative light microscope radioautographs of galactose-3H and phlorizin-3H were prepared from freeze-dried plastic-embedded hamster small intestine incubated in vitro. The usual uphill epithelial cell accumulation of galactose accompanied by a somewhat smaller lamina propria accumulation was observed in control tissue incubated 3 min in 1 mM galactose-3H. The addition of 5 x 10-4 M phlorizin to the medium blocked uphill accumulation, but did not prevent galactose equilibration with the epithelial cells. The galactose content of the lamina propria was considerably less than the galactose content of the epithelial cell. Varying the phlorizin-3H content of the medium from 0.6 to 60 µM revealed a brush border binding of phlorizin which followed a Langmuir adsorption isotherm with a half-saturation constant of 13 µM and a maximum binding of 84 µmoles of phlorizin/liter of microvilli or 2.6 x 106 sites/epithelial cell. The phlorizin content of the epithelial cell compartment, excluding microvilli, never exceeded 10% that of the medium after 20 min of incubation. These findings directly support the view that phlorizin is a nontransported inhibitor which binds glucose-galactose carriers at the surface of epithelial cell microvilli.

scholarly journals In Vitro Neurotoxicity Resulting from Exposure of Cultured Neural Cells to Several Types of Nanoparticles

2017 ◽  
Vol 10 ◽  
pp. 117967071769452 ◽  
Author(s):  
Stephen F Larner ◽  
Jonathan Wang ◽  
Jared Goodman ◽  
Megan B O’Donoghue Altman ◽  
Meiguo Xin ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cadmium Selenide ◽  
Morphological Analysis ◽  
Neural Cells ◽  
Cell Cytoplasm ◽  
Cell Viability Assay ◽  
Pc 12 Cells ◽  
The Past ◽  
Viability Assay

Laboratory and industrial production of various nanoparticles, single-walled nanotubes (SWNTs), fullerene (C60), cadmium selenide (CdSe) quantum dots, carbon black (CB), and dye-doped silica nanospheres (NSs), has greatly increased in the past 15 years. However, little research has been done to analyze the toxicity of these materials. With recent studies showing that nano-substances can cross the blood–brain barrier, we examined the neurotoxicity of these manufactured nanoparticles. By employing the rat PC-12 neuronal-like cell line as the basis for our studies, we were able to evaluate the toxicity caused by these five nanoparticles. The level of toxicity was measured by testing for cell viability using the lactate dehydrogenase (LDH) cell viability assay, morphological analysis of changes in cellular structures, and Western blot analyses of αII-spectrin breakdown products (SBDP) as cell death indicators. Our results showed cytotoxicity in nondifferentiated PC-12 cells exposed to CB (10–100 µg/mL), SWNTs (10–100 µg/mL), C60 (100 µg/mL), CdSe (10 µg/mL), CB (500 µg/mL), and dye-doped silicon NSs (10 µg/mL). Exposure to higher concentrations (100 µg/mL) of SWNTs, CB, and C60 increased the formation of SBDP150/145, as well as cell membrane contraction and the formation of cytosolic vacuoles. The incorporations of the nanoparticles into cell cytoplasm were observed using the fluorescent dye-doped NSs in both nondifferentiated and nerve growth factor (NGF)-differentiated PC-12 cells. When PC-12 cells are differentiated, they appeared to be even more sensitive to cytotoxicity of nanoparticles such as CB 10 nm (10–100 µg/mL), CB 100 nm (10–100 µg/mL), and CdSe (1–10 µg/mL).

Scanning Electron Microscopy of Human Jejunum in Whipple's Disease

1977 ◽  
Vol 35 ◽  
pp. 354-355
Author(s):  
John H. L. Watson ◽  
C. N. Sun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Basement Membrane ◽  
Lamina Propria ◽  
Brush Border ◽  
Whipple’S Disease ◽  
Whipple's Disease ◽  
Biopsy Specimens ◽  
Brush Borders ◽  
Scanning Electron

That the etiology of Whipple's disease could be bacterial was first suggested from electron micrographs in 1960. Evidence for binary fission of the bacteria, their phagocytosis by histiocytes in the lamina propria, their occurrence between and within the cells of the epithelium and on the brush border of the lumen were reported later. Scanning electron microscopy has been applied by us in an attempt to confirm the earlier observations by the new technique and to describe the bacterium further. Both transmission and scanning electron microscopy have been used concurrently to study the same biopsy specimens, and transmission observations have been used to confirm those made by scanning.The locations of the brush borders, the columnar epithelial cells, the basement membrane and the lamina propria beneath it were each easily identified by scanning electron microscopy. The lamina propria was completely filled with the wiener-shaped bacteria, Fig. 1.

Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza
Keyword(s):  
Controlled Release ◽  
Xanthan Gum ◽  
In Vitro Release ◽  
Correlation Coefficients ◽  
High Ratio ◽  
Water Soluble ◽  
Metformin Hydrochloride ◽  
Model Drug ◽  
Very High

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

NGHIÊN CỨU ẢNH HƯỞNG CỦA CHITOSAN HOÀ TAN TRONG NƯỚC ĐẾN NẤM Colletotrichum musae D1 GÂY BỆNH THÁN THƯ TRÊN CHUỐI Ở ĐIỀU KIỆN IN VITRO

2016 ◽  
Vol 119 (5) ◽  
Author(s):  
Lê Thanh Long ◽  
Nguyễn Văn Toản ◽  
Nguyễn Văn Huế ◽  
Trang Sĩ Trung ◽  
Vũ Ngọc Bội
Keyword(s):  
Water Soluble ◽  
28S Rrna ◽  
Colletotrichum Musae

Chủng D1 phân lập từ các mẫu chuối có vết bệnh thán thư điển hình được sử dụng để nghiên cứu khả năng kháng nấm của chitosan hoà tan trong nước (Water-soluble chitosan_WSC) ở điều kiện in vitro. Kết quả phân tích trình tự gen mã hoá 28S rRNA của chủng D1 cho thấy tương đồng trình tự cao với các trình tự tương ứng của loài Colletotrichum musae và được ký hiệu là Colletotrichum musae D1. Kết quả các thí nghiệm đều cho thấy C. musae D1 rất nhạy cảm với WSC, hiệu lực ức chế tăng khi tăng nồng độ WSC xử lý ở điều kiện in vitro. Trên môi trường PDA, nồng độ 1,6% WSC ức chế hoàn toàn sự sinh trưởng của sợi nấm C. musae D1, nồng độ ức chế 50% (PIRG50) và nồng độ ức chế tối thiểu 90% (MIC90) tương ứng với nồng độ WSC 0,28% và 0,88%. Trong môi trường PDB, giá trị IC50 và MIC90 tương ứng là 0,11% và 0,43% và sự phát triển của sợi nấm C. musae D1 bị ức chế hoàn toàn ở nồng độ 0,8%. WSC không chỉ ức chế sự nảy mầm mà còn gây biến đổi bất thường bào tử nấm khi quan sát trên kính hiển vi.

Fenofibrate Solid Dispersion for Improving Oral Bioavailability: Preparation, and Characterization and in vivo Evaluation

2020 ◽  
Vol 13 (5) ◽  
pp. 5102-5109
Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi
Keyword(s):  
Oral Bioavailability ◽  
Oral Delivery ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
In Vivo Evaluation

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.

Solubility Enhancement of Poorly Water-Soluble Antifungal Drug Acyclovir by Nanocrystal Formulation Approach

2018 ◽  
Vol 11 (2) ◽  
pp. 4036-4042
Author(s):  
Prakash Goudanavar ◽  
Ankit Acharya ◽  
Vinay C.H
Keyword(s):  
Chemical Interaction ◽  
Research Work ◽  
Antiviral Drug ◽  
In Vitro Release ◽  
Oral Route ◽  
Water Soluble ◽  
Precipitation Method ◽  
Dsc Studies ◽  
Ft Ir

Administration of an antiviral drug, acyclovir via the oral route leads to low and variable bioavailability (15-30%). Therefore, this research work was aimed to enhance bioavailability of acyclovir by nanocrystallization technique. The drug nanocrystals were prepared by anti-solvent precipitation method in which different stabilizers were used. The formed nanocrystals are subjected to biopharmaceutical characterization including solubility, particle size and in-vitro release. SEM studies showed nano-crystals were crystalline nature with sharp peaks. The formulated drug nanocrystals were found to be in the range of 600-900nm and formulations NC7 and NC8 showed marked improvement in dissolution velocity when compared to pure drug, thus providing greater bioavailability. FT-IR and DSC studies revealed the absence of any chemical interaction between drug and polymers used. 

Formulation and Evaluation of Orally Disintegrating Tablets of Lamotrigine

2015 ◽  
Vol 8 (2) ◽  
pp. 2881-2888
Author(s):  
Sudarshan Singh ◽  
S S Shyale ◽  
P Karade
Keyword(s):  
Drug Release ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Disintegration Time ◽  
Orally Disintegrating Tablet ◽  
Drug Content ◽  
Weight Variation ◽  
Wetting Time ◽  
Croscarmellose Sodium

The aim of this study was to design orally disintegrating tablet (ODT) of Lamotrigine. It is an Antiepileptic drug which is widely used in epilepsy. It is also used in simple and complex partial seizures and secondary generalized tonic-clonic seizures. It is poorly water soluble drug (0.46 mg/ml). Thus, an attempt was made to enhance the water solubility by complexation with β-cyclodextrin (1:1 molar ratios). The orally disintegrating tablet of lamotrigine was prepared by direct compression method using different concentration of superdisintegrants such as Sodium starch glycollate, croscarmellose sodium by sublimating agent such as camphor. The formulations were evaluated for weight variation, hardness, friability, drug content, wetting time, in vitro disintegration time and in vitro dissolution studies. The prepared tablets were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The disintegration time for the complexed tablets prepared by different concentration of superdisintegrants was found to be in range of 32.54 ± 0.50 to 55.12 ± 0.57 sec and wetting time of the formulations was found to be in range of 28.47 ± 0.67 to 52.19 ± 0.72 sec. All the formulation showed almost 100 percent of drug release within 15 min. Among all the formulation F6 and F7 prepared with 18% croscarmellose sodium and camphor shows faster drug release, respectively 10 min, F6 gives good result for disintegration time, drug release, wetting time and friability. Further formulations were subjected to stability testing for 30 days at temperature of 40 ± 5 ºC/75 ± 5 %RH. Tablets showed no appreciable changes with respect to physical appearance, drug content, disintegration time and dissolution profiles. Results were statistically analyzed by one-way ANOVA at a p < 0.05. It was found that, the data at any point of time are significant at p < 0.05.

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