Lysosomes

Clinical Cancer Nanomedicine

Nanotechnology offers new solutions for the development of cancer therapeutics that display improved efficacy and safety. Although several nanotherapeutics have received clinical approval, the most promising nanotechnology applications for patients still lie ahead. Nanoparticles display unique transport, biological, optical, magnetic, electronic, and thermal properties that are not apparent on the molecular or macroscale, and can be utilized for therapeutic purposes. These characteristics arise because nanoparticles are in the same size range as the wavelength of light and display large surface area to volume ratios. The large size of nanoparticles compared to conventional chemotherapeutic agents or biological macromolecule drugs also enables incorporation of several supportive components in addition to active pharmaceutical ingredients. These components can facilitate solubilization, protection from degradation, sustained release, immunoevasion, tissue penetration, imaging, targeting, and triggered activation. Nanoparticles are also processed differently in the body compared to conventional drugs. Specifically, nanoparticles display unique hemodynamic properties and biodistribution profiles. Notably, the interactions that occur at the bio-nano interface can be exploited for improved drug delivery. This review discusses successful clinically approved cancer nanodrugs as well as promising candidates in the pipeline. These nanotherapeutics are categorized according to whether they predominantly exploit multifunctionality, unique electromagnetic properties, or distinct transport characteristics in the body. Moreover, future directions in nanomedicine such as companion diagnostics, strategies for modifying the microenvironment, spatiotemporal nanoparticle transitions, and the use of extracellular vesicles for drug delivery are also explored.

Strategies for improving drug delivery: nanocarriers and microenvironmental priming

INTRODUCTION

The ultimate goal in the field of drug delivery is to exclusively direct therapeutic agents to pathological tissues in order to increase therapeutic efficacy and eliminate side effects. This goal is challenging due to multiple transport obstacles in the body. Strategies that improve drug transport exploit differences in the characteristics of normal and pathological tissues. Within the field of oncology, these concepts have laid the groundwork for a new discipline termed transport oncophysics. Areas covered: Efforts to improve drug biodistribution have mainly focused on nanocarriers that enable preferential accumulation of drugs in diseased tissues. A less common approach to enhance drug transport involves priming strategies that modulate the biological environment in ways that favor localized drug delivery. This review discusses a variety of priming and nanoparticle design strategies that have been used for drug delivery. Expert opinion: Combinations of priming agents and nanocarriers are likely to yield optimal drug distribution profiles. Although priming strategies have yet to be widely implemented, they represent promising solutions for overcoming biological transport barriers. In fact, such strategies are not restricted to priming the tumor microenvironment but can also be directed toward healthy tissue in order to reduce nanoparticle uptake.

Ameliorative effect of Drynaria quercifolia (L.) J. Sm., an ethnomedicinal plant, in arthritic animals

Drynaria quercifolia (L.) J. Sm., is an ethnomedicinal plant used widely in Tamil Nadu to treat arthritis. The present study was aimed to evaluate the traditional claim of D. quercifolia rhizome water extract in adjuvant induced arthritic animals. Anti-arthritic effect was studied by assessing the levels of lysosomal enzymes, protein bound carbohydrates, urinary degradative collagen and serum cytokines on control and adjuvant induced arthritis. The paw swelling and body weight were also analyzed. The levels of ROS and lysosomal enzymes in neutrophils of control and adjuvant induced animals were also estimated. D. quercifolia rhizome water extract at doses of 100 and 200mg/kg reduced the paw thickness and elevated the mean body weight of arthritic rats. The treatment with extract showed a significant reduction in the levels of plasma and liver lysosomal enzymes as well as protein bound carbohydrates and urinary degradative collagen levels. The treatment reduced the levels of ROS and lysosomal enzymes in neutrophils significantly. The significant reduction in the levels of serum pro-inflammatory cytokines (TNF-α and IL-1β) and the increment in the levels of anti-inflammatory cytokine (IL-10) were also observed by the treatment. The present study supports the traditional claim of using D. quercifolia to treat rheumatism.

Probing structural changes in the α and β domains of copper- and silver-substituted metallothionein by emission spectroscopy and electrospray ionization mass spectrometry

Steady-state emission spectra, excited-state lifetimes, kinetic data, and mass spectroscopic properties are reported for Ag(I)- and mixed Ag(I)/Cu(I)-substituted alpha and beta domains of recombinant human metallothionein (MT1a). Kinetic analysis of the changes in the Cu(I) emission spectra during the stepwise displacement of Cu(I) ions by Ag(I) at room temperature shows that the rate of displacement of Cu(I) is unexpectedly slow. Although the first Ag(I) added results in major changes in the Cu(I)-MT binding site, Cu(I) displacement by Ag(I) does not take place until the addition of the third Ag(I), and is completed by the addition of the seventh Ag(I). The emission from Ag(I) and mixed Cu(I)/Ag(I)-MT species at 77 K shows that the band maxima shift as a function of Ag(I) loading, which can be correlated with shifts in coordination geometry from trigonal to digonal. Two phosphorescence lifetimes were detected for the Ag(I)-substituted alpha and beta domains of MT, which are attributed to the presence of Ag(I) ions in two different environments. The lifetime of Ag(I)-substituted MT was found to be shorter when the Ag(I)-MT species were formed by Ag(I) additions to the Cu(I)-substituted alpha and beta fragments than when the Ag(I)-MT species were formed from the apo-alpha and apo-beta fragments, suggesting the formation of structurally different Ag(I)-MT clusters. Electrospray ionization mass spectrometric studies suggest the metallation reactions of Ag(I) with MT take place in a series of steps to form a series of Ag(I)-substituted MT species. Ag(I)-substituted MT species are not detected until past the addition of 3 mol equiv of Ag(I), suggesting that cluster formation begins only at this point, stabilizing the metallated species sufficiently to survive ionization.

Acid phosphatase activity in the chick's inner ear

The cellular localization of distribution of acid phosphatase (AP) in the plastic sections of newly hatched chick's inner ear were investigated utilizing an azo-coupling method. AP activity as evidenced by azo dye deposits were well defined and localized in various cells of membranous labyrinth. Intense AP activity was detectable in the supranuclear area of hair cells in the basilar papilla and vestibular sensory hair cells. As in the case of the other sites of AP activity, marked AP activity was seen in the supranuclear area of the transitional epithelia of crista ampullaris and in the supranuclear area, or diffusely in the cytoplasm of the dark cells at the base of crista ampullaris. The columnar cells and the cells of tegmentum vasculosum showed moderate to strong AP activity. The statoacoustic and vestibular ganglion cells showed various degrees of AP activity. On the AP activity of statoacoustic or vestibular ganglion, in comparison between the sections from JB-4 Plus embedded specimens and those from LR White embedded specimen, the latter could more intensely demonstrate AP activity than the former. Moreover, sections fixed in 2.5% paraformaldehyde demonstrated more intense AP activity than those fixed in 2.5% glutaraldehyde.

Rat kidney lysosomal membrane damage induced by suramin in vitro and in vivo

The effect of suramin, an acid naphthylamine, on rat kidney lysosomal membrane integrity was studied. Lysosomal particles were incubated with suramin (0.1-0.4 mM) and light scattering behaviour of the mixtures were subsequently measured. There was a significant decrease (P less than 0.005) in the amount of light absorbed in the presence of suramin compared to lysosomal particle suspension alone. This was accompanied by release of acid phosphatase, a lysosomal 'marker' enzyme, into the suspending medium. These effects were reduced in the presence of acetylsalicylic acid, a known lysosomal membrane stabilizer. Administration of suramin to rats resulted in loss of kidney acid phosphatase and lysozyme activities from the tissue. These results indicate labilization of rat kidney lysosomal membrane by suramin molecules both in vitro and in vivo.

Dose related effects of dexamethasone treatment on the ultrastructure of articular cartilage in rats

Corticosteroid administration is known to cause degenerative changes in articular cartilage interfering with the cell metabolism of chondrocytes. The present study analyzes the ultrastructural changes in chondrocytes after systemic dexamethasone acetate treatment in relation to dosage, using a standardized morphometrical method. Five male Wistar rats of 300 g body weight in each experimental group were subjected to 3, 4 and 5 mg dexamethasone acetate by intramuscular injections of 1 mg per week. 1000 electron micrographs of single chondrocytes in the middle zone of hyaline cartilage from the knee joints were evaluated with standardized morphometry and nonparametric statistics. With increasing dexamethasone dosage the amount of rough endoplasmic reticulum and Golgi apparatus decreased. Considerably increased glycogen granula and clusters indicated a severe change in glycolytic pathways. Lysosomes duplicated in number. Degenerative changes were also manifested in lipid droplets and myeloid bodies, which, like the amount of microfilaments, exhibited a clear dosage-dependent increase under dexamethasone treatment. The ratio of dead versus living chondrocytes increased in relation to dosage up to 25% cell mortality.

The inflammatory reaction in an experimental model of open wounds in the rat. The effect of arachidonic acid metabolites

The study concerned the effect of arachidonic acid metabolites on the inflammatory reaction in granulation tissue of open wounds in rats. Metabolites or inhibitors were applied in a wound chamber attached to circular, open, full-thickness skin wounds 5 days post-wounding. The adjacent wound served as control. Blood flow, albumin extravasation and accumulation of polymorphonuclear leucocytes (PMNLs) were measured in the granulation tissue. Prostaglandin E2 (PGE2 5.7 microM) increased blood flow and albumin extravasation by 95 and 16%, respectively, without affecting PMNLs. Leukotriene B4 (LTB4 2.7 microM) increased PMNL accumulation by 142% without altering albumin extravasation. Indomethacin (28 microM, repeatedly) did not affect blood flow or albumin extravasation, but increased PMNL accumulation by 21%. Methylprednisolone (3.3 mM, repeatedly) reduced blood flow and albumin extravasation by 29 and 31%, respectively, without influencing PMNLs. The granulation tissue obviously responds to exogenous PGE2 and LTB4. Endogenous arachidonic acid metabolites seem to play only a minor role in the inflammatory process in this model.

Effect of chloroquine on the stability of rat kidney lysosomes in vivo and in vitro

1. Chronic administration of chloroquine to rats results in increased urinary excretion of lysosomal acid phosphatase, muramidase and cathepsin D. 2. Various concentrations of chloroquine caused lysosomal membrane swelling as shown by decrease of light absorbance in lysosomal suspensions. 3. Incubating lysosomal suspensions in the presence of chloroquine resulted in a marked lysosomal acid phosphatase release. 4. Addition of acetylsalicylic acid, a lysosomal membrane stabilizer, into a lysosomal suspension containing chloroquine, reduced the degree of lysosomal membrane swelling and acid phosphatase release. 5. The results suggest a labilizing effect of chloroquine on rat kidney lysosomes.

Influence of CW microwave radiation on in vitro release of enzymes from retinol- treated hepatic lysosomes

Hepatic lysosomes were exposed in vitro to microwave radiation (2450 MHz) either prior to or simultaneously with treatment with retinol (vitamin A), and the release of the lysosomal enzymes, beta-glucuronidase, acid phosphatase, and cathepsin D, determined. A 60-min microwave exposure (10 or 100 mW/g) of retinol-treated lysosomes had no effect on the amount of release of beta-glucuronidase, cathepsin D, or acid phosphatase. In addition, 10 and 100 mW/g irradiation of lysosome fractions for 40 min prior to a 20-min retinol and microwave treatment, had no influence on the release of these enzymes. Finally, the effect of microwave radiation on the loss of latency of acid phosphatase and beta-glucuronidase from retinol-treated lysosomes was determined. Microwave radiation had no influence on the rate of appearance of these enzymes in the suspending medium. The results indicate that microwave radiation had no effect on the retinol-induced lysosomal enzyme release.

Activated macrophages in human periodontitis

Fifteen patients, eight males and seven females, ranging from 30 to 88 years of age with advanced periodontal disease were selected for this study. Biopsies and blood samples were taken of both normal and inflamed gingival tissues, and processed for detection of nonspecific esterase and acid phosphatase activity in monocytes and macrophages. Activated macrophages, as indicated by their intense reaction to acid phosphatase and nonspecific esterase, were found in the gingival epithelium, lamina propria, perivascular tissues and in the blood vessels in human chronic periodontitis. Blood smears of monocytes showed variability of stain intensity suggesting that their activation occurred in blood vessels where they marginate and emigrate into the perivascular tissues in chronic periodontitis. They then appear as macrophages that migrate through the connective tissue, penetrate the basement membrane and continue through the epithelium. The nonspecific esterase stain identified T-cells, by a singular dot-like granule, and plasma cells by multiple granules in the cytoplasm. Lymphocytes containing multiple cytoplasmic nonspecific esterase positive granules commonly were found only in the perivascular connective tissue and may represent B-cell differentiation to plasma cells. The plasma cell predominance, the presence of T-cells and activated macrophages indicated both humoral and cell-mediated responses are operative in human chronic periodontitis.

Ochronotic arthropathy and lysosomes: a clinical and electron microscopic study

In order to understand better the time dependency of the arthritic manifestations of ochronosis, as well as its relationship with lysosomal activities, we sampled a small series of various arthropathies (11 joints). The joint fluid, serum, and urine lysosomal activity levels were measured. The lysosomal enzyme level was elevated in patients with acutely symptomatic, chronically involved ochronotic joints. The enzyme activity level in the other joints (chronically involved) was less. Postulated clinical manifestations of increased levels of intraarticular lysozymes seem to apply to ochronosis as well. Further studies with larger series of patients are warranted.

A recent immunological concept of some nasal diseases

In this study, we have attempted to summarize and clarify the concept of nasal permeability to antigens such as inhaled particles, bacterial breakdown products and medicaments. The mature epithelium retains the capacity to allow macromolecules to penetrate by a pinocytotic mechanism, which is more pronounced during the neonatal period. The vast majority of individuals have no ill effects from the nasal transport of large molecules. However, when increased quantities of toxic or antigenic macromolecules gain access to the body because of a derangement in the protective mucosal barriers (namely: the Secretory IgA (SIgA), the mucous plug with the cilia, the intracellular digestion or interstitial immunoglobulins and macrophages), antigen absorption may be altered and result in either local or systemic disorders. The speculative concepts suggesting that clinical disease-states (e.g. allergy, atrophic rhinitis, rhinoscleroma, infection and malignancy), may be associated with altered mucosal permeability have also been discussed.

Microwave irradiation and in vitro release of enzymes from hepatic lysosomes

An exposure system for examining in vitro effects of microwave irradiation on cellular and subcellular components has been developed. The system was used to test the effect of 2.45-GHz CW microwaves on the release of two lysosomal enzymes. At a specific absorption rat (SAR) of 10, 50 or 100 mW/g (90 min) no effects were noted at 37 degrees C (pH of 7.3) on lysosomal fragility as determined by the release of the lysosomal enzymes cathepsin D and beta-glucuronidase. When the medium was adjusted to pH 5.0, microwave irradiation of the lysosomal suspension had no effect on the acid-induced enhancement of release of lysosomal enzymes. The data indicate that microwave irradiation had no labilizing effect on the lysosomal membrane, although other microwave-membrane interactions not associated with enzyme release may occur.

The significance of lysosomal enzymes in middle ear effusions

Although lysosomal enzymes have been demonstrated in middle ear effusions by several investigations, the exact source of these enzymes and the role they play in the maintenance and progression of otitis media with effusion have not been thoroughly studied. The source of lysosomal enzymes in middle ear fluids and their possible role in the inflammatory process in otitis media with effusion are explored.

The receptor concept: prejudice, prediction, and paradox

Major progress has been achieved in understanding the chemical nature of receptors for certain hormones and neurotransmitters. Some of these units have been obtained as homogenous proteins; concept and technology are adequate to permit the detailed chemical and structural analysis of these macromolecular units. The critical problem which now arises is to define how a receptor once "occupied" and "activated" serves to initiate action. Elucidation of details of receptor structure, in of itself, will not solve the "coupling problem" in hormone action. New concepts, as well as new technics, will probably be necessary. In this discussion I have raised the possibility that metals coordinated to hormone receptor complexes may be the "trigger" element involved in initiating action, serving to alter the state of functional units in binary fashion. In effect, the metal determines whether the "state" of the system is active or inactive. As stated previously in connection with the action of steroid hormone receptor complexes, the specific suggestions made relating metals to the hormone coulping process have been advanced primarily to illustrate the conceptual gap which exists with respect to "coupling." The present suggestions may prove to be correct or untenable, in whole or in part. If it turns out that metals play a central role in the coupling process of hormone action, perhaps via completely different mechanisms than those suggested here, one of the central ideas of receptor action developed by the pioneers who created the receptor concept will have been resurrected in principle, if not in detail. In science, as in life generally, conceptual progress once achieved sometimes turns out to be the rediscovery of the past.

Increased relative growth rate of normal rat cells in vitro with crocetin

The carotenoid crocetin (earlier found to increase relative growth of Walker 256 tumor cells and their radiosensitivity), is shown to increase the relative growth of normal Sprague-Dawley rat muscle derived cells in vitro, presumably by increasing oxygen transport.

Effect of mannitol, dextran (macrodex), allopurinol, and methylprednisolone on the morphology of the proximal tubule of the rat kidney made ischemic in vivo

Rats were anesthetized and their lift kidneys were made ischemic for 1 h by clamping of the aorta just above the left renal artery. Mannitol (2.5 g/kg), Dextran 70 (0.6 g/kg), methylprednisolone (50 and 100 mg/kg), and allopurinol (100 mg/kg body weight) were administered before, during, or after the ischemia period in order to test the effect of each of these drugs upon this model of renal injury. At 24 h after the release of the aortic clamp the left kidneys of the drug treated animals wwere perfusion fixed and processed for light and electron microscopy. Dextran administration to animals with ischemic kidneys gave rise to a pronounced vacuolization ("osmotic nephrosis"), in the entire proximal tubule and especially in the pars recta. This was in contrast to dextran administration to rats with nonischemic kidenys, which showed no or very mild "osmotic nephrosis." This demonstrates that ischemia makes rat kidneys more susceptible to the development of "osmotic nephrosis." In controls (no drug treatment) one hour of renal ischemia gave partial necrosis of pars recta of the proximal tubule, while the pars convoluta tubule survived. Mannitol treatment significantly reduced the amount of necrosis of the pars recta, whereas dextran, methylprednisolone, and allopurinol had no or a negative effect on the survival of the cells of the pars recta segment. It is suggested that mannitol protects against the development of necrosis by increasing medullary blood flow in combination with a counteractive influence on the cellular swelling, which is known to occur in ischemia.

Leukemic mitochondria. II. Acute monoblastic leukemia

Qualitative and quantitative ultrastructural studies were performed on mitochondria of leukemic monoblasts from 15 patients with acute monoblastic leukemia. Similar comparative observations were made on mitochondria of myeloblasts from 14 hematologically normal controls. No significant quantitative differences were noted between normal and leukemic mitochondria. Area measurements were approximately equal. Qualitative differences between the two groups consisted of increased numbers of irregularly shaped mitochondria, damaged mitochondrial membranes, mitochondria with damaged matrix, and small granules in mitochondria in the leukemic group. Leukemic cells exhibited nuclear-mitochondrial contact and virus-like particles within damaged mitochondria. To confirm the presence of virus-like particles and to aid in our understanding of nuclear-mitochondrial interaction, a C-type virus producer MSV-MLV infected rat embryo cell culture was used for additional analysis. Mitochondrial abnormalities and increased frequency of virus in damaged mitochondria, often attached to mitochondrial membranes, were noted. Several lysosomes exhibited accumulations of virus and budding into lysosomes from lysosomal membranes. Mitochondria are important organelles in glycolytic-oxidative phosphorylation pathways, and carry extranuclear genetic information. Further studies of morphologic and biochemical abnormalities of leukemic mitochondria and the interaction between the mitochondria and the nuclei in leukemic cells are needed to provide researchers with data on extranuclear factors operating in oncogenesis.

Ultrastructural changes produced in rheumatoid synovial membrane by chrysotherapy

Biopsies of rheumatoid synovial membrane before and after chrysotherapy were examined with the light and electron microscopes, and subjected to electronprobe x-ray analysis. The main change noted was the occurrence of electron-dense deposits of characteristic morphology within pre-existing lysosomes. Such deposits were also seen in other varieties of lysosomal bodies. X-ray analysis showed the presence of gold, phosphorus, osmium, and calcium in these deposits. The present study shows that gold enters the pre-existing lysosomes, supporting the concept that the beneficial effects of chrysotherapy are due to its action on the lysosome.

Arylsulfatse B in colorectal cancer

Arylsulfatase B activity has been determined in 24-hour urine samples from 243 patients with colorectal cancer. Elevated activity of the enzyme was obsereved in 172 out of 243 (71%) patients. Employing Dukes' modified classification of colorectal cancer, urine arylsulfatase B activity was elevated in Dukes' A lesions-1/8 (12%), Dukes' B lesions-24/43 (55%). Dukes' C lesions-89/111 (80%), and Dukes' D lesions-66/81 (82%). Arylsulfatase B activity in urine, when elevated, may be used to follow response to therapy since in those patients with elevated urine arylsulfatase B values who subsequently responded to therapy, the enzyme values became or approached normal. Urine arylsulfatase B activity also correlated with plasma carcinoembryonal antigen (CEA) as a diagnostic indicator of colorectal cancer in 33/46 (71%) patients. In contrast to the urinary findings, arylsulfatase B activity in tumor tissue was elevated in only 24% (27/110) of the specimens of colorectal cancer. It was also found that in a group of 55 patients treated with 5-fluorouracil, all of the 13 patients that showed objective response to therapy had activities of arylsulfatase B in the tumor tissue within the normal range for large bowel mucosa. Nevertheless, 22 to 26 of the 43 patients that did not respond also presented values in the normal range. The roles of lysosomal enzymes in colorectal cancer are discussed.

Antigen absorption from the small intestine and gastrointestinal disease

In this article, I have attempted to summarize the concept of intestinal permeability to antigens such as ingested food proteins, bacterial breakdown products, endotoxins, and enzymes. The mature gut retains the capacity to absorb macromolecules by a pinocytotic mechanism which is more pronounced during the neonatal period. The vast majority of individuals have no ill effects from the intestinal transport of large molecules. However, when increased quantities of toxic or antigenic macromolecules gain access to the body because of a derangement in the intraluminal digestive process or because of a defect in the mucosal barrier, antigen absorption may be altered and result in either local intestinal or systemic disorders. The speculative concepts suggesting that clinical disease states may be associated with altered mucosal permeability have been discussed.

The lysosomal permeability test modified for toxicity testing with cultured heart endothelioid cells

A modified lysosomal fragility test is described which is suitable for use with cultured cells. The permeability (fragility) of the lysosomal membranes of the cells to the substrate beta-glycerophosphate is measured by assessing the degree of particulate lysosomal straining seen after exposing the cells to the Gomori acid phosphatase staining reaction under carefully controlled conditions. Monolayer cultures of endothelioid cells from the hearts of neonatal rats have been used in all experiments. The time-course of lysosomal straining for cells exposed to various treatments (normal saline, isotonic sucrose, 0.25 m sucrose, distilled water, acetate buffer pH 5.0, cold acetone, neutral formalin, acetic-ethanol, Triton X-100, hydrocortisone, choloroquine and vitamin A) was compared with that of control cells stained under identical conditions. Statistical differences in staining between the test and control cells were determined by the Wilcoxin Signed Rank Test and also by regression analysis following a transformation designed to allow for the saturation character of the reaction. The success of the modified technique depends upon meticulous methodology. It is capable of demonstrating both lysosomal membrane labilization and stabilation, second- and third-stage lysosomal activation, and apparent lysosomal enzyme loss or destruction in situ. The technique also allows the degree of reversible or first-stage lysosomal activation to be subdivided on an almost continous basis and is suitable for investigating the effects of drugs and other agents on the integrity of the lysosome in situ.

Biogenic amine concentrations in traumatized spinal cords of cats. Effect of drug therapy

✓ Concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT), and histamine (HIST) were determined in spinal cords of five groups of cats. One group underwent laminectomy only; a second untreated group received a 400 gm-cm impact at the T-9 level. These were compared with three groups treated with epsilon aminocaproic acid (EACA), methyl prednisolone sodium succinate (MP), and a combination of EACA and MP after similar trauma. The biogenic amines were measured in three 1-cm segments of the cord, rostral, middle, and caudal, 1 hour after trauma. There was no change in NE concentration in any of the three segments after impact compared with laminectomized controls, nor was the NE concentration in the impacted (middle) area higher than that in the rostral or caudal sites. Although the NE content of the cord in treated animals decreased compared to that of laminectomized controls, the decrease was not significant. The concentration of DA, however, significantly increased after impact and significantly decreased after treatment with EACA and EACA plus MP. There was no significant change in 5-HT levels, but the level of HIST increased significantly after impact and was lowered by treatment with EACA and EACA with MP. The implications of these changes in biogenic amines in spinal cord trauma are discussed.