Lumen Loading

A typical presynaptic bouton is a specialized portion of the axon. It is characterized by an active zone, a region where the presynaptic plasma membrane comes into close contact with the postsynaptic plasma membrane and an associated cluster of vesicles (De Camilli et al., 2001). A few synaptic vesicles are adjacent to the active zone and are referred to as docked vesicles. Vesicle exocytosis occurs at the active zone subsequent endocytic retrieval of vesicular components may occur both at the active zone and in the peri-active zone area (Roos and Kelly, 1999). Vesicle maturation involves acidification of the lumen, loading with the neurotransmitter, association with peripheral membrane proteins needed for exocytosis, and recapture into a vesicle cluster. The vesicle cluster is embedded in an ac tin-rich area and is generally located next to mitochondria, which provides the energy required for the vesicle cycle and neurotransmitter dynamics and to the endoplasmic reticulum whose function includes the regulation of local cytosolic calcium. 

Green HV, Fox TJ, Scallan AM (1982) Lumen-loaded paper pulp. Pulp Pap Can 83(7) T203-T207 Haggblom-Ahnger U (1998) Three ply office paper. Doctoral thesis, Abo akadcani University, ISBN 952-12-0288-2, Turku... 

Middleton SR, Desmeules J, Scallan AM (2003) Lumen loading with calcium carbonate fillers. J Pulp Paper Sci 29(7) 241-246... 

Yamada H, Hara N (1987) Synthesis of calcium carbonate by electrical conductivity monitoring. In Proceedings of the first international conference on ceramic powder processing science, Florida, The American Ceramic Society, Ohio, pp 39-46 Zakaria S, Ong BH, van de Ven TGM (2004a) Lumen loading magnetic paper I flocculation. 

A device with shape memory technology and osmotic delivery has been developed to treat patients who suffer from a painful bladder condition known as interstitial cystitis/bladder pain syndrome (TARIS Biomedical Inc., MA). The device was made of a dual-lumen silicone catheter with one lumen loaded with lidocaine, which continuously leached out as contacted with urine. The second lumen of the device contains superelastic nitinol wire in a predefined form, which provides the... 

S. Middleton, J. Desmeules, A. Scallan, Lumen Loading with Calcium Carbonate Fillers,/. Pulp Paper Sci. 2003, 29 (7), 241-248. 

Ink detachment is more difficult to model than deflaking. Ink is attached to fiber with a certain adhesive force. If this attachment force is greater than the force applied by the rotor, the ink will remain attached to the fiber. Ink can also be hidden in fiber interstices, and thus not be subjected to the rotor forces. Both these factors contribute to a floor level of ink that remains following repulping. Further, ink can be redeposited onto or inside the fiber once it has been detached from the fiber surface. The latter phenomenon, called lumen loading, is a function of mixing action, which increases with ink concentration and the duration and intensity of suspension treatment. 

HoUow-fiber membranes, therefore, may be divided into two categories (/) open hoUow fibers (Eigs. 2a and 2b) where a gas or Hquid permeates across the fiber waU, while flow of the lumen medium gas or Hquid is not restricted, and (2) loaded fibers (Eig. 2c) where the lumen is flUed with an immobilized soHd, Hquid, or gas. The open hoUow fiber has two basic geometries the first is a loop of fiber or a closed bundle contained ia a pressurized vessel. Gas or Hquid passes through the smaU diameter fiber waU and exits via the open fiber ends. In the second type, fibers are open at both ends. The feed fluid can be circulated on the inside or outside of the relatively large diameter fibers. These so-caUed large capiUary (spaghetti) fibers are used in microfUtration, ultrafUtration (qv), pervaporation, and some low pressure (<1035 kPa = 10 atm) gas appHcations. 

A maximum loading of 5.5 wt% at pH 1 when both lumen and outermost surface are positive is close to full loading (about 12 vol% taking into account that the density of the clay is approximately twice that of the drug). Minimum 2 % loading was at pH 9 when both halloysite lumen and Dexamethasone have the same negative charge. 

Fig. 14.12 Nanoparticle co-loading 10-nm silica inside halloysite lumen.

CaC03 precipitation is clearly visible in Figure 14.14, which is a TEM image of halloysite cross-sections. Halloysite has >90% of the tubular form with outer diameter 50 5nm and inner diameter of the lumen 15 nm. The length of the initial halloysite is less than 1 micron, which results in a substantially short diffusion path length. The calculated value of the free inner space indicates the ability to load a maximum 14 3 % of the total volume ofthe halloysite. The entrapment efficiency of 5 % by volume was estimated. 

We carefully dissected rat tail arteries and loaded them with a Ca2+ indicator, Fluo-3. After a rectangular glass capillary was inserted into the lumen of the excised arteries, [Ca2+] in smooth muscle cells within the arterial wall was visualized using a confocal microscope. Brief electrical shocks were delivered at 5 Hz to the preparations to stimulate the sympathetic nerve network present in the adventitia. We found Ca2+ signals with diverse spatiotemporal patterns, Ca2+ waves and oscillations in individual smooth muscle cells during the sympathetic nerve stimulation (lino et al 1994). 

A solution of styrene in methanol to impregnate wood samples, followed by polymerization, was used by Furuno and Goto (1979). Penetration of the monomer into the cell wall was determined by solvent extraction of samples after polymerization. This removed lumen located polymer, whilst leaving the cell wall bound polymer in place. This showed that the concentration of cell wall bound polymer increased in proportion to the monomer content in methanol, up to a maximum of 80% of the monomer in the solvent. No cell wall penetration was observed for treatment with neat monomer. This was also found for bulking of the wood, as determined from external dimensions of the samples. Improvements in ASE were obtained as a result of the presence of cell wall bound polymer. To achieve similar ASE values with lumen located polymer required very high polymer loadings. 

Figure 7 The stability of liposomal VCR in liposomes prepared using different triethylammonium ion gradients. VCR can be deformylated under acidic conditions, similar to those found in the intraliposomal lumen of remote-loaded liposomes. (A) The deformylated product is inactive compared to the parent drug. (B) HPLC chromatograms show peaks for both VCR (rt = 9.5 minutes) and deformylated VCR (rt= 11.1 minutes) for liposomes prepared with either sulfate or citrate as the intraliposomal trapping agent and stored for three months at 4°C to 6°C. Abbreviation VCR, vincristine.

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