Receptor mediated targeting of liposomes

The targeting of liposomes to cells and the delivery of the liposomal contents into the cells have been investigated using either α-melanocyte stimulating hormone or Ricin-B-chain as ligands for promoting the binding of liposomes to cells. α-melanocyte stimulating hormone has been conjugated to liposomes and to Ricin-A-chain via the Lys₁₁ residue without significant loss of biological activity. The resulting conjugates were found to bind to Bl6 melanoma cells which express receptors for the hormone. Hormone targeted ricin was shown to be toxic to the cells, indicating receptor mediated internalisation of the conjugate. The hormone targeted liposomes however were unable to mediate the delivery of cytotoxic levels of methotrexate. Ricin-B-chain, a lectin which mediates membrane translocation of the toxic ricin-A-chain, was examined for its applicability for targeting of liposomes to cells. This lectin was shown to promote the binding of liposomes to cells and to mediate the delivery of cytotoxic concentrations of methotrexate. Further evidence of functional ricin-B-chain mediated intracellular delivery of the liposomal contents was shown by liposome mediated transformation of cells, and delivery of nuclease into the cell resultin in digestion of genomic DNA. The study demonstrates that α-melanocyte stimulating hormone is unsuitable as a ligand by which to achieve delivery of large quantities of material into cells, although cell-specific targeting can be achieved. Ricin-B-chain is however ideally suited for this task, though is less cell-specific. This finding may be of use in studies in which investigators wish to achieve intracellular delivery of compounds

A MAPPING OF OXIDATIVE ENZYMES IN THE HUMAN BRAIN *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65177/1/j.1471-4159.1962.tb11860.x.pd

PROXIMO-DISTAL INCREASE OF ENZYMIC ACTIVITY IN THE DORSAL SPINAL TRACTS *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65919/1/j.1471-4159.1964.tb06151.x.pd

A COMPARATIVE MAPPING OF ENZYMES INVOLVED IN HEXOSEMONOPHOSPHATE SHUNT AND CITRIC ACID CYCLE IN THE BRAIN *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66082/1/j.1471-4159.1963.tb05042.x.pd

An enzyme histochemical study of torpedoes and dendritic swellings in the cerebellum

In 8 cases, the following enzymes were studied in the dendritic swellings and torpedoes of Purkinje cells of cerebellum: succinic dehydrogenase, cytochrome oxidase, lactic dehydrogenase, NAD-diaphorase, alkaline phosphatase, acid phosphatase, acetyl cholinesterase and nonspecific cholinesterase. Activity of the oxidative enzymes was always extremely high in the dendritic swellings, but varied greatly among cases in the torpedoes; 4 cases showed very weak activity of oxidative enzymes in torpedoes, while 4 other cases showed an intense reaction. Dendritic swellings and torpedoes exhibited no alkaline phosphatase, acetyl cholinesterase, or nonspecific cholinesterase activity. In Dendritenanschwellungen und Torpedos der Purkinje-Zellen des Kleinhirns von 8 Fällen wurden die folgenden Enzyme untersucht: Bernsteinsäure-Dehydrogenase, Cytochrom-Oxidase, Milchsäure-Dehydrogenase, NAD-Diaphorase, alkalische Phosphatase, saure Phosphatase, Acetylcholinesterase und unspezifische Cholinesterase. Die Aktivität der oxidativen Enzyme war in den Dendritenanschwellungen immer sehr hoch, in den Torpedos aber von Fall zu Fall sehr unterschiedlich: 4 Fälle zeigten nur sehr geringe Aktivität, die 4 anderen jedoch eine sehr intensive Reaktion. Die Dendritenanschwellungen und Torpedos zeigten keine Aktivität der alkalischen Phosphatase, Acetylcholinesterase oder unspezifischen Cholinesterase.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47226/1/401_2004_Article_BF00687526.pd

Photophysics of closed- and open-ring isomers of a diarylethene with a carboxylic anchor group

We study the transient photophysical properties of a diarylethene with a carboxylic anchor group by a combination of steady-state and ultrafast emission and absorption spectroscopy. After excitation of the closed-ring form, fluorescence with a quantum yield of 10−5 is observed and separated into different spectro-temporal components. The S1 state of the closed-ring form shows a lifetime of 1.3 ps and decays mainly by internal conversion to the S0 state of this isomer. This vibrationally hot ground state cools on a time scale of 10 ps

A COMPARISON OF CHOLINESTERASE DISTRIBUTION IN THE CEREBELLUM OF SEVERAL SPECIES *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65142/1/j.1471-4159.1964.tb06717.x.pd

Rekindling the love of books - a pilot project exploring whether e-readers help people to read again after a stroke

Background E-readers may facilitate reading in aphasia through “aphasia-friendly” features such as altering text size and formatting (Worrall et al, 2005), and text-to-speech functions. However, no previous research has examined whether e-readers help people with aphasia to read. Aims This project explored: • whether people with aphasia can learn to use e-readers following a brief period of training • whether e-reader training improves reading comprehension • whether e-readers increase participation in and enjoyment of reading activities Method and procedures In phase one, available e-readers were compared using an expert evaluation against a set of criteria, to identify the model with optimum accessibility features and fewest potential barriers. The Kindle Keyboard 3G TM (Amazon) was selected for trialling in phase two. Four people with self-reported reading difficulties post-stroke participated in phase two. All had mild or mild-moderate aphasia. Four one-hour training sessions aimed to trial accessibility features, identify helpful features, and teach independent operation of these. A repeated measures design was used. Outcome measures assessed reading comprehension (Gray Oral Reading Tests, Bryant & Wiederholt, 2001) and confidence and emotions associated with reading (Reading Confidence and Emotions Questionnaire, Cocks et al., 2013). Matched texts were used to compare reading comprehension using printed texts and the e-reader. Usability evaluations explored independence in e-reader use and acceptability of the technology. Participation in reading activities and reading enjoyment were explored using qualitative exit interviews. Outcomes and results Participants’ reading comprehension on the Kindle, as measured by the GORT-4, did not improve following training and did not exceed comprehension of printed texts. However, reading confidence improved significantly for three of the participants (RCEQ: p<.05, p<.01 and p<.005). Analysis of exit interviews and usability evaluations indicates that three out of four participants preferred reading on the Kindle to printed texts. These participants read more frequently on the Kindle than they had done before the training, and the technology enabled them to access more challenging texts (e.g. novels). They appreciated different features of the Kindle. Two participants experienced difficulties operating the technology, one of whom would have benefited from a longer training period. Conclusions This pilot study suggests that a short block of e-reader training led to improvements in reading confidence, participation and enjoyment. E-readers were not shown to enhance reading comprehension. Larger-scale investigations are warranted to further investigate whether and how e-readers facilitate reading for people with aphasia