Water-soluble, meso-substituted cationic porphyrins--a family of compounds for cellular delivery of oligonucleotides.

The delivery of oligonucleotides to appropriate intracellular compartments is crucial to their development as tools in gene function studies and as therapeutics. Here, we report the characterization of meso-substituted cationic porphyrins as a large class of water-soluble reagents for oligonucleotide delivery. These porphyrins form non-covalent complexes with single-stranded oligonucleotides and deliver these molecules into the nuclei of cell lines in culture. The porphyrins protect oligonucleotides from nuclease degradation, and delivery is unaffected by the presence of serum. Delivery capacity is dependent on the charge ratio and concentration of the oligonucleotide and porphyrin used to form the complex, on the chemical substituents of the oligonucleotide and on the identity of the cationic porphyrin. This class of molecules provides a versatile set of water-soluble delivery reagents that could contribute to the development of oligonucleotide drugs.

Turning difficulty characteristics of adults aged 65 years or older.

BACKGROUND AND PURPOSE: Falls that occur while walking have been associated with an increased risk of hip fracture in elderly people. This study's purpose was to describe movement characteristics in older adults that serve as indicators of difficulty in turning while walking. SUBJECTS: Three groups were assessed: young adults who had no difficulty in turning (age range=20-30 years, n=20) (YNDT group), elderly adults who had no difficulty in turning (age range=65-87 years, n=15) (ENDT group), and elderly adults who had difficulty in turning (age range=69-92 years, n=15) (EDT group). METHODS: All subjects were videotaped performing a self-paced 180-degree turn during the Timed "Up & Go" Test. Movement characteristics of each group were identified. Four characteristics were used to identify difficulty in turning: (1) the type of turn, (2) the number of steps taken during the turn, (3) the time taken to accomplish the turn, (4) and staggering during the turn. RESULTS: In general, the EDT group took more steps during the turn and more time to accomplish the turn than the YNDT and ENDT groups. Although the only turning strategy used by the YNDT group was a pivot type of turn, there was an almost total absence of a pivot type of turn in the EDT group. No differences were found among the groups on the staggering item, yet the EDT group was the only group in which staggering was present. We believe these changes observed in the 4 characteristics only in the EDT group are indicators of difficulty in turning while walking. CONCLUSION AND DISCUSSION: These indicators of difficulty may be useful for the early identification of individuals aged 65 years or older who are having difficulty in turning and may well serve as the basis for the development of a scale for difficulty in turning in older adults. Preliminary findings indicate the need for further study into the reliability, validity, and sensitivity of measurements obtained with such a scale.

Acute effects of locomotor training on overground walking speed and H-reflex modulation in individuals with incomplete spinal cord injury.

OBJECTIVE: The purpose of this study was to assess the effect of a single bout of a locomotor-training paradigm on overground walking speed and H-reflex modulation of individuals with incomplete spinal cord injury (SCI). METHODS: Self-selected and maximum walking speeds and soleus H-reflexes (H/M ratios) during standing and stance and swing phases of walking (self-selected velocity) were obtained from 4 individuals with American Spinal Injury Association impairment classification D. Data were collected immediately before and after a single bout of locomotor training with body weight support on a treadmill. The pretraining H/M ratios of the SCI subjects were also compared with values from 4 able-bodied subjects who did not receive the intervention. Maximum H/M ratios while standing and during midstance and midswing phases of overground walking were considerably greater in the SCI subjects than in the control subjects. RESULTS: After the single bout of training, self-selected and maximum overground walking speeds of the subjects with SCI increased by 26% and 25%, respectively. Furthermore, H-reflexes were significantly more depressed in the SCI subjects during overground walking (28% less during stance, 34% less during swing). CONCLUSIONS: Although preliminary, these findings indicate that a single bout of locomotor training produced immediate increases in walking velocity and acute neurophysiologic changes in individuals with incomplete SCI.

The potential of virtual reality and gaming to assist successful aging with disability.

Using the advances in computing power, software and hardware technologies, virtual reality (VR), and gaming applications have the potential to address clinical challenges for a range of disabilities. VR-based games can potentially provide the ability to assess and augment cognitive and motor rehabilitation under a range of stimulus conditions that are not easily controllable and quantifiable in the real world. This article discusses an approach for maximizing function and participation for those aging with and into a disability by combining task-specific training with advances in VR and gaming technologies to enable positive behavioral modifications for independence in the home and community. There is potential for the use of VR and game applications for rehabilitating, maintaining, and enhancing those processes that are affected by aging with and into disability, particularly the need to attain a balance in the interplay between sensorimotor function and cognitive demands and to reap the benefits of task-specific training and regular physical activity and exercise.

Complexation, Stability and Behavior of L-Cysteine and L-Lysine with Different Iron Sources.

Effective stability constants for cysteine and lysine with five different iron sources were evaluated along with their behavior in solution. The values obtained for ferric chloride-cysteine, ferrous sulfate-cysteine, ferric chloride-lysine, ferrous sulfate-lysine, hydrogen-reduced lysine, and electrolytic-reduced lysine were 6.81 × 102 to 2.78 × 103, 1.33 × 105 to 1.36 × 105, 6.00 × 10-4 to 7.64 × 10-3, 6.37 ×10-4 to 4.82× 10-3, 9.34 × 10-2 to 1.38 × 10-1, and 4.18 × 10-4 to 7.27 × 10-4, respectively. No measurable complexation occurred with hydrogen- and electrolytic-reduced iron with cysteine nor with ferric orthophosphate and cysteine or lysine. The stability of soluble ferric cysteine over the pH range 2.0 to 7.4 indicates that this complex has the potential to be used as an iron additive in food. Approximately half of the hydrogen and electrolytic reduced iron and only 0.11% of ferric orthophosphate were soluble in acid, whereas ferric chloride and ferrous sulfate were completely soluble. Qualitative evaluation of the iron-amino acid systems over a range of pH from 2.0 to 12.0 indicated that there was a mixed valence state of free iron in most cases with low pH favoring reduction and high pH oxidation, until precipitation of iron hydroxides occurred.

Delivery of oligoribonucleotides to human hepatoma cells using cationic lipid particles conjugated to ferric protoporphyrin IX (heme).

The receptor-ligand interaction between hepatocyte heme receptors and heme was evaluated as a basis for developing a targeted cationic lipid delivery reagent for nucleic acids. Heme (ferric protoporphyrin IX) was conjugated to the aminolipid dioleoyl phosphatidylethanolamine (DOPE) and used to form cationic lipid particles with dioleoyl trimethylammonium propane (DOTAP). These lipids particles (DDH) protect oligoribonucleotides from degradation in human serum and increase oligoribonucleotide uptake into 2.2.15 human hepatoma cells (to a level of 50-60 ng oligo/10(4) cells) when compared with the same lipid particles (DD) prepared identically without heme. The DDH heme level that was optimal for oligoribonucleotide delivery was also optimal for maximum expression of plasmid-encoded luciferase. The enhancing effect of heme was evident only at net particle negative charge. Fluorescence microscopy showed that DDH delivered oligoribonucleotides into both the 2.2.15 cell cytoplasm and nucleus. DDH may thus be a potentially useful delivery vehicle for oligonucleotide-based therapeutics and transgenes, appropriate for use in such liver diseases as viral hepatitis, hepatoma, and hypercholesterolemia.