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OBJECTIVE To examine the effect of treating uncorrected refractive error through spectacle correction on vision-targeted health-related quality of life and depressive symptoms in nursing home residents. METHODS Persons aged 55 years or older residing in nursing homes in Birmingham, Alabama, having uncorrected refractive error were randomly assigned to either immediate spectacle correction of uncorrected refractive error or delayed correction (after the 2-month follow-up visit). MAIN OUTCOME MEASURES Vision-targeted health-related quality of life (measured with the Nursing Home Vision-Targeted Health-Related Quality-of-Life Questionnaire and the VF-14) and depressive symptoms (measured with the Geriatric Depression Scale), assessed at baseline and at 2 months. RESULTS At the 2-month follow-up, the immediate refractive error correction group as compared with the delayed correction group had higher scores on the Nursing Home Vision-Targeted Health-Related Quality-of-Life Questionnaire subscales of general vision, reading, psychological distress, activities and hobbies, and social interaction (all P < .04) and the VF-14 (P < .001) as well as fewer depressive symptoms on the Geriatric Depression Scale (P = .003), adjusting for mental status and baseline outcome variables. CONCLUSIONS Dispensing spectacles to treat uncorrected refractive error in nursing home residents leads to improved quality of life and decreased symptoms of depression. APPLICATION TO CLINICAL PRACTICE This study demonstrates that older adults residing in nursing homes can personally benefit from access to the most basic of eye care services. TRIAL REGISTRATION clinicaltrials.gov Identifier: "http://clinicaltrials.gov/show/NCT00347620">NCT00347620Arch Ophthalmol.2007;125(11):1471-1477--

OBJECTIVE To characterize habitual visual acuity, contrast sensitivity, spectacle use, and eye care utilization in a large sample of older adults residing in nursing homes. METHODS Of 33 nursing homes identified in Birmingham, Alabama, 17 served as sites. Eligibility criteria included age 55 years or older, English-speaking, and Mini-Mental State Examination score of 13 or higher. Habitual distance and near visual acuity and contrast sensitivity were measured for each eye and binocularly. Residents and a family member/guardian were interviewed about spectacle use and eye care utilization. Medical records provided information on demographics, chronic medical conditions, date of last eye examination, duration of residence in the nursing home, and health insurance. RESULTS Of 380 enrollees, 57% had distance visual acuity in the better eye worse than 20/40; 10% had visual acuity of 20/200 or worse. Near visual acuity was slightly worse on average by a line than distance acuity. Three-fourths of residents had abnormal binocular contrast sensitivity. The medical record had no record of or reference to an eye examination for 66% of enrollees despite 90% having health insurance. CONCLUSION The high rate of visual impairment in nursing homes underscores the need to understand its causes and to evaluate interventions to address this public health challenge.Arch Ophthalmol.2007;125(7):925-930--

Cyclopropanation of allylic tertiary amines using the Simmons−Smith reagent has been achieved by employing chelating groups in close proximity to the amine. The chelating groups promote cyclopropanation at the expense of N-ylide formation. Using pseudoephedrine as the chelating group, high diastereoselectivity is observed.

Zinc-complexed methylene ammonium ylides are formed from tertiary amines and the Simmons−Smith reagent. These stable entities can be activated with n-BuLi to allow reactions typical of ammonium ylides such as [2,3] rearrangements. In the case of oxazolidine 12, ylide formation, activation, and subsequent [2,3] rearrangement was highly efficient and occurred with very high diastereoselectivity.

The practicalities of the asymmetric hydrogenation of acetophenone derivatives are addressed. The catalysts used, derived from the precatalysts [(xylylPhanePhos)RuCl2(DPEN)] (S)-(R,R)-1 and (R)-(S,S)-1, were shown to possess very high reactivity. 4‘-Fluoroacetophenone was hydrogenated at a molar substrate-to-catalyst ratio (S/C) of 100,000 with complete conversion effected in as little as 80 min (average turnover ~1200 min^-1, peak turnover ~2500 min^-1). The catalysts are tolerant of a range of commercial grade substrates, in most cases a S/C of 5000−10000 was achieved without the need to purify the ketone. Using precatalyst 1 enantioselectivities of 95 → 99% ee were achieved. The high selectivity and catalyst activity, plus the simplicity of the process, offers significant advantages over other enantioselective ketone reductions.

The mitochondria in type-I and -II muscle fibres in the pectoralis major muscle of the pigeon (Columba livia) have been analysed using stereological techniques not previously applied in muscle biology.

The acroblast of Helix spermatids is a duplex structure: it consists of an ‘externum’ (which appears dark by positive phase-contrast microscopy and becomes impregnated with osmium) enclosing a region called the ‘internum’. Histochemical studies show the externum to be composed principally of phospholipid and to contain glycolipid, alkaline phosphatase, and an enzyme which splits thiamine pyrophosphate. The internum contains neutral mucopolysaccharide. Ribonucleic acid and acid phosphatase are not present in the acroblast. These histochemical results suggest a homology between the invertebrate acroblast and the Golgi apparatus in vertebrate cells.

Spermatids of the snail Helix aspersa were studied after fixation in buffered osmium tetroxide and after applying Novikoff and Goldfischer's method (15) for demonstrating thiamine pyrophosphatase (TPPase) activity both with the light and the electron microscope. The appearance of cells in the light microscope after localizing the enzyme is very similar to the appearance after the application of classical Golgi techniques. The electron microscope shows the "dictyosomes" to consist of non-granular membranes, vesicles, and vacuoles typical of the ultrastructure of the Golgi apparatus. Sites of TPPase activity are localized by deposits of lead phosphate, and are found between the membranes of the Golgi apparatus, in the small vesicles, in multivesicular bodies often found associated with it, but not within the large Golgi vacuoles. Heavy deposits are found on the caudal part of the nuclear envelope, but not in the acrosomal granule. It is suggested that TPPase may act as an intermediary in acrosome formation by the Golgi apparatus or "acroblast" of this cell. The finding of diphosphatase activity in the Golgi apparatus of an invertebrate is suggested as additional evidence for the existence of a homology between the Golgi apparatus of all animal cells.

The three kinds of lipid globules recognizable in the living neurones of Helix aspersa have been examined under the electron microscope. The globules of the kind that can be stained blue with methylene blue during life are seen in electron micrographs as spheres or spheroids, with concentric lamination, after calcium-osmium fixation. After fixation with sucrose-osmium laminated crescentic bodies are seen instead; these appear to be formed by distortion of the ‘blue’ globules. The yellow globules contain electrondense material, and sometimes appear reticular. It is possible that the yellow globules may originate by transformation of some of the ‘blue’ globules. The colourless globules generally appear as crenated objects; this appearance may be a shrinkage artifact. Apart from the mitochondria and the three kinds of lipid globules described, no other object large enough to be identified with the light microscope has been seen in the cytoplasm.

The fibrocytes and the fibres of Hirudo medicinalis have been studied with the electron microscope. The fibrocyte can be shown by other methods to contain triglyceride droplets, phospholipid droplets, and mitochondria, all of which can be recognized in the electron micrographs. In addition, a ‘vesicular’ component has been observed just below the cell surface. The collagenous ‘cortex’ of the fibre is tubular, and can be shown to contain a long process of the cell which secretes it. There are many small fibrils about 250 Å in diameter comprising the cortex of the fibre; they lie along the fibre axis, and often are associated in pairs or groups of three or four. These fibrils sometimes show a poorly defined periodicity of 300 Å. It seems that the fibrils ‘shred off’ from the surface of the fibrocyte. The process shows some resemblance to that described in the chick by other authors.

The classical site of the ‘Golgi apparatus’, the Purkinje cells of the cerebellum of owls, has been examined by electron microscopy. The greater part of the cytoplasm consists of aggregates of closely packed granular membranes ofendoplasmic reticulum. The objects described by Dalton and Felix in electron micrographs and called by them the Golgi apparatus are rarely seen in these preparations. It seems likely that the ‘Golgi apparatus’ of this cell as seen in the optical microscope is formed by the deposition of silver or osmium on the membranes of the endoplasmic reticulum, which form a network throughout the cytoplasm of this cell.

The action of buffered potassium permanganate as a fixative for electron microscopy has been investigated. Electron contrast has been shown to be produced by the deposition of granular material in the tissue. The particles are about 50 Å in diameter. Actual fixation of the tissue is performed by the dehydrating alcohol. Histochemical studies have shown that RNA and histones are removed, whereas phospholipid-protein complexes are ‘unmasked’. The reaction of the permanganate with unmasked protein gives rise to high membrane contrast in electron micrographs.

The two distinct types of cytoplasm seen with the light microscope in the adipose cell of the leech Glossiphonia complanata have been identified in the electron microscope image of this cell. One of these, the basophil cytoplasm, contains many well oriented, paired membranes which are much more clearly evident when calcium ions are added to the fixative. The membranes sometimes appear as concentric arrays of lamellae and are thought to represent sections through a phospholipide-containing body. The paired membranes and the concentric lamellae have granules attached to them and resemble in size and structure the membranes of the endoplasmic reticulum encountered in many mammalian cells. Small dense cytoplasmic particles are present throughout the cell; they may be ferritin molecules, derived from the breakdown of haemoglobin taken in as food. On the basis of a previous histochemical study and the present electron microscope investigation, it is suggested that these paired membranes are similar to the organized type of mammalian ER and the results seem to confirm the belief that these membranes are composed of layers of phospholipoprotein together with attached particles of ribonucleoprotein.

In the course of a light and electron microscopy study of spermatogenesis in the European crayfish, Astacus fluviatilis, spermatocytes of abnormal appearance were observed in two instances in individuals that had passed the mating period. The electron microscope showed that the inner membrane of the nuclear envelope of these cells was erupting into a mass of microtubules, 15 to 18 mµ in diameter and 0.5 µ or more in length, while the outer membrane transformed into cytoplasmic vesicles. Stages in the formation of these novel processes were followed. The plasma membrane of the affected cells was seen in some cases to erupt into similar although shorter microtubules. It is concluded that the phenomenon is part of a degenerative process in which the spermatocytes are being absorbed by sustentacular cells. It is suggested that the observations provide further evidence for a fundamental functional as well as a morphological similarity between the membranes bounding the nucleus and the plasma membrane.

ALTHOUGH the pathological changes in muscular dystrophy are commonly attributed to a primary abnormality of the muscle fibres, there is evidence to suggests that mucular dystrophy may be attributable to a neuronal abnormality1. This has become known as the ‘neural hypothesis’. Dystrophic mice (Bar Harbor 129 REJ dy/dy) provide a useful model of muscular dystrophy for experimental study. In spite of the early onset of abnormal reflexes in muscular dystrophy, the richly innervated sensory organs, muscle spindles, have received relatively little attention2,3. Optical microscopical studies have indicated that spindles in dystrophic mouse muscles are essentially unaffected4, although in some human diseases they seem to undergo minor changes5. This study was undertaken to establish whether there are ultrastructural changes in spindles of dystrophic mice which are detectable only by electron microscopy.

The sensory organs of skeletal muscles, the muscle spindles, were examined using electron microscopy indy2J/dy2Jdystrophic mice. Despite widespread damage to the extrafusal (skeletomotor) fibres the intrafusal (spindle) fibres appeared normal and seemed resistant to the aetiological factors for murine dystrophy.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.