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At least 523 records · Page 29Linked to original sources
PubMed2005

Early detection of thinning of retinal nerve fiber layer in glaucomatous eyes by optical coherence tomography 3000: analysis of retinal nerve fiber layer corresponding to the preserved hemivisual field.

The retinal nerve fiber layer (RNFL) thickness was measured with the optical coherence tomography using version 3.0 software (OCT3000) in 153 eyes of 153 normal subjects. The mean of the average RNFL thickness over the entire 360 degrees in the control group was 92.5 +/- 12.9 microm which was significantly thinner than the normative data of 95.9 +/- 11.4 microm included with the OCT3000 (p < 0.01). The RNFL thickness decreased with increasing age (p < 0.01, r = -0.395). The RNFL thickness was also measured in 53 eyes of 53 patients with glaucoma whose superior (13 eyes) or inferior (40 eyes) perimetric hemifields were normal. Only the RNFL thickness corresponding to the preserved perimetric hemifields were measured by OCT3000 and scanning laser ophthalmoscopy (SLO). The RNFL thickness in the superior and inferior 30 degrees sectors, the maximum and average RNFL thickness in the superior (S(max) and S(avg)), and inferior quadrants (I(max) and I(avg)) were analyzed. The S(max), S(avg), I(max), I(avg), and the RNFL thickness in the superior (p < 0.05), superotemporal and inferotemporal sectors (p < 0.01) in the glaucoma patients without a nerve fiber layer defect (SLO) were significantly thinner than in the control subjects in same age. OCT3000 measurements showed that the RNFL thickness in glaucomatous eyes with normal perimetric visual fields and SLO was significantly thinner than the RNFL thickness in normal eyes.

Adult↗
PubMed1997

Does nerve fiber layer thickness correlate with visual field defects in glaucoma? A study with the nerve fiber analyzer.

The Nerve Fiber Analyzer, a confocal scanning laser ophthalmoscope, was used to measure the thickness of the retinal nerve fiber layer (NFL) in a glaucoma population. The authors studied the correlation between NFL thickness and the perimetric defects. The NFL was found to be statistically thinner in comparison to a normal control group of subjects. The correlation between the perimetric index MD and the NFA was statistically significant only for the lower quadrant of retinal NFL. The correspondence between thinner NFL and perimetric defects was investigated.

Glaucoma↗
PubMed2005

Development of a multiwavelength Raman fiber laser based on phase-shifted fiber Bragg gratings for long-distance remote-sensing applications.

We propose a simple and flexible multiwavelength Raman fiber laser based on phase-shifted fiber Bragg gratings (FBGs) and a tunable chirped FBG. Using a simple multiwavelength Raman laser configuration with a single phase-shifted FBG and a tunable chirped FBG, we readily achieved simultaneous two-channel sensing probes with a high extinction ratio of more than 50 dB over a 50-km distance. The multiwavelength output was stable and the peak fluctuation was less than 0.5 dB. The temperature and strain sensitivities are estimated to be 10.1 pm/degrees C and 7.5 pm/microstrain, respectively.

Environmental Monitoring↗
PubMed2006

Meeting the dietary reference intakes for fiber: sociodemographic characteristics of preschoolers with high fiber intakes.

To better understand the public health impact of the National Academy of Sciences' Dietary Reference Intakes (DRIs) for fiber in preschoolers, I analyzed data from the United States Department of Agriculture Continuing Survey of Food Intake in Individuals for 5437 preschoolers and examined sociodemographic predictors of meeting the DRIs. Overall, only 12% of the children met the DRIs. Older children (age 4 and 5 years) were less likely than younger children, girls were less likely than boys, and children from medium-income families (those earning 186% to 350% of the poverty guidelines, with poverty set at 100%) were least likely to meet the DRIs. Low-income children participating in the Special Supplemental Nutrition Program for Women, Infants, and Children were twice as likely as nonparticipants to meet the DRIs. The public should be educated about the importance of increasing fiber density in the diet.

Age Factors↗
PubMed1994

Effects of cobalt on in vitro fiber digestion of forages and by-products containing fiber.

Cobalt glucoheptonate as a source of Co to enhance ruminal fiber digestion was evaluated in two in vitro digestibility experiments. In Experiment 1, Co supplementation (0, 5, and 10 ppm) of five substrates (leaf and stem fractions of alfalfa and orchardgrass hays and ground corn) was evaluated under two dietary conditions (ruminal fluid taken from steers fed alfalfa hay or a high concentrate diet) for 24 or 48 h of fermentation in a 3 x 5 x 2 x 2 factorial arrangement. In Experiment 2, four concentrations of Co (0, 10, 20, and 30 ppm) were added to five substrates (alfalfa hay, orchardgrass hay, corn cobs, recycled newsprint treated with HCl, and cellulose casings) and were incubated with ruminal fluid from steers fed alfalfa hay for 24 or 48 h of fermentation in a 4 x 5 x 2 factorial arrangement. No interactions among treatments were observed for digestibilities of DM, OM, or NDF in both experiments or for VFA concentrations in Experiment 1. Supplementation with Co did not increase digestibilities of DM, OM, or NDF in either experiment or concentrations of VFA in Experiment 1. In Experiment 1, in vitro digestibilities of DM, OM, and NDF were higher for inoculum from steers fed alfalfa versus concentrate. In Experiment 2, digestibilities of DM, OM, and NDF were highest for alfalfa hay and lowest for recycled newsprint treated with HCl. Cobalt concentrations that were above minimum requirements did not improve digestion of DM, OM, or fiber.

Animals↗
PubMed1991

Fecal output, gastrointestinal transit time, frequency of evacuation and apparent excretion rate of dietary fiber in young men given diets containing different levels of dietary fiber.

Five healthy young male subjects were given meals containing different levels of dietary fiber (DF) for one week each, and the effects on the fecal output, gastrointestinal transit time, frequency of evacuation, and apparent excretion rate of dietary fiber in feces were studied. The experiments were conducted twice by varying the subjects and the DF levels. The following results were obtained. 1) With an increase in the intake of DF, feces increased significantly in both wet weight and volume. The fecal specific gravity did not show any clear-cut relation with the intake level of DF. 2) The gastrointestinal transit time tended to shorten in each DF period compared to the DF-free period. However, it did not shorten with an increase in the intake level of DF. 3) Frequency of evacuation tended to be high in any of the DF periods compared to the DF-free period. However, the differences in the intake level of DF produced no changes in the frequency. 4) The DF content in feces increased significantly with an increase in the intake of DF, indicating that the larger the fecal output, the larger the fecal DF content. The apparent mean excretion rate of DF in feces remained in the range of 60-75% throughout the two experimental phases. Residues in feces other than DF increased with an increase in the DF intake. 5) The results obtained here indicate that the DF intake of at least 20 g per day produces 140-150 g of fecal output which can be easily excreted daily by a normal adult person.

Adult↗
PubMed1999

[Measurement of retinal nerve fiber layer thickness of normal eyes with nerve fiber analyzer].

OBJECTIVE: To study the retinal nerve fiber layer thickness (RNFLT) of normal eye and the correlation with age. METHODS: RNFLT of 198 cases of normal eyes were examined by using nerve fiber analyzer (NFA). RESULTS: There were significant inverse linear correlation between the RNFLT and age (r = -0.46, P < 0.01). In the analysis by the quadrant, the RNFLT was correlated with age in the superior and inferior quadrant. The mean ratio of superior and inferior quadrant thickness (S/I) was 1.041. CONCLUSION: NFA seems to be an useful tool to measure the RNFLT quantitatively. The RNFLT of normal eye is found to be decreased with age.

Adolescent↗
PubMedDate not supplied

Inconsistent differences between neutral detergent fiber and total dietary fiber values of fruits and vegetables.

A large number of fruits and vegetables were analyzed to determine levels of neutral detergent fiber (NDF) and total dietary fiber (TDF). The results showed that the TDF method is more precise than the NDF method. Further, the NDF values are significantly higher than the TDF values for apples and for miscellaneous fruits and vegetables, and significantly lower for stonefruit. For berryfruit, the differences between the NDF and TDF data are not significant. Also, a significant interaction between sample and method (except for berryfruit) indicated that, within groups, the (TDF-NDF) values vary so much that a "group difference" does not exist; consequently, figures from one method cannot be estimated from results of the other.

Dietary Fiber↗
PubMed1980

[Acute spongiform leucoencephalopathy with selective intramyelinic involvement of U fibers associated with an ovarian carcinoma. Syndrome of disconnection of U fibers (author's transl)].

Case report of clinical, pathological and ultrastructural features in an acute spongiform leucoencephalopathy with selective involvement of U fibers. A 52 years old woman exhibited an acute encephalopathy of 2 months duration, with dementia and multifocal impairment of cortical functions. The cerebral cortex was normal. This acute dementia resulted from a diffuse intercortical disconnection. Spongy degeneration was only found in U fibers. No other changes were noted especially in basal ganglia, optics tracts, and spinal cord. The white matter status spongious was related to an intramyelinic oedema. Such intramyelinic oedema is known only in Van Bogaert and Bertrand and Canavan disease, which is quite different, and in toxic encephalopathies, especially those induced by the hexachlorophene and triethyltin. In the present case no drugs or toxins were found. An ovarian carcinoma was found at post-mortem examination.

Acute Disease↗
PubMed1995

Functional and anatomical fiber analysis of the posterior commissure (PC) in the cat: evidence for PC fibers of which stimulation elicits non-oculosympathetic pupillary dilation.

Pupillary responses were studied by electrical stimulation of the posterior commissure (PC) and the nuclei of origin and termination of PC fibers in the cat. Prior to stimulation experiments, cervical sympathectomy was carried out to study the pupillary responses not mediated by the ocular sympathetic nerve. Pupillary responses were recorded by using an infrared pupillo-analyzing system. The stimulus consisted of a 5 s train of cathodal square wave (0.5 ms duration, 50 Hz) pulses. Stimulation of the PC evoked a pupillary response complex (PRC), which began with a rapid pupillary constriction after the latency of 210-317 ms. The threshold of constriction was 10 or 20 microA. Constriction reached its peak shortly after the onset of the stimulus, then the pupil gradually re-dilated (pupillary escape, PE) even though the stimulus was still lasting. The pupil gradually returned, after stimulus termination, to the size before stimulation in the cases with the pupil area before stimulation larger than 20 mm2. On the other hand, in the cases with smaller pupil area before stimulation (< 20 mm2), rapid constriction and PE were followed, after stimulus termination, by a large dilation (after-dilation, AD). The thresholds of PE and AD were 20 or 40 microA. Pupillary constriction was evoked with a large range of stimulus frequency (1-100 Hz). To evoke PE and AD, stimulus frequencies of 10 and 50 Hz were required respectively, and lower frequencies were ineffective. The peak latency of AD increased in proportion to the increase in stimulus frequency and intensity. Following horseradish peroxidase (dissolved in 5% alkyl-phenol ethylene oxide) injection into the pretectal region where fibers from the PC fan out, retrogradely labeled neurons occurred in many subthalamic, pretectal and midbrain nuclei on the other side. They were classified into three groups in terms of the pupillary response evoked by electrical stimulation; the pupillo-constrictory nuclei (PCNs) of which stimulation evoked constriction with the threshold of 20 microA, the pupillo-dilatory nuclei (PDNs) of which stimulation evoked dilation with the threshold of 20 or 10 microA, and other nuclei with higher thresholds of constriction or dilation. The PDNs were further, classified into two groups (Type 1 and Type 2 PDNs) according to the relationship between stimulus intensity and the peak latency of dilation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Effects of chamber shape and fiber orientation on relations between fiber dynamics and chamber dynamics.

The function of a chamber depends on its hydrodynamic properties: isometric pressures it can exert in the operating range of distensions, compliances in the operating range of distensions, and wall-displacement resistances in the operating range of distensions. Wall-displacement resistance is the departure of pressure from isometric pressure relative to rate of cavity-volume change. The dependence of pressure on average stress and wall/cavity volume ratio is indifferent to chamber shape, which suggests that the volume-based compliance-elastance and resistance-viscosity equations would be only moderately shape dependent. The present study shows that this supposition is correct. If the wall is thin, these relations are shape indifferent. At higher wall/cavity volume ratio, cylindricity increases slightly the P-V-curve slope relative to elastance and either increases slightly or does not affect resistance relative to viscosity. The compliance-elastance and resistance-viscosity relations also depend only slightly on fiber orientation. Therefore, with the sphere equations, one can account accurately for normal and abnormal function of a prolate spheroid in terms of volume dimensions of the wall and apparent average fiber properties.

Blood Vessels↗
PubMed1986

DNA sequence of the tail fiber genes 37, encoding the receptor recognizing part of the fiber, of bacteriophages T2 and K3.

The DNA sequences of genes 37 of bacteriophages T2 and K3 are presented and compared with that of phage T4. The corresponding proteins constitute, as dimers, the part of the long tail fibers that recognizes the bacterial receptor. The CO2H termini of the polypeptides are located at the free ends of the fibers. Morphologically, the three phages are essentially identical, but they use different receptors. The genes from phages T4, T2 and K3 encode proteins consisting of 1026, 1341 and 1243 amino acid residues, respectively. DNA-DNA hybridizations had shown earlier that genes 37, in contrast to the gene for the major capsid protein, of a number of T-even type phages are highly polymorphic. The deduced amino acid sequences now show that this polymorphism extends to the protein primary structures. About 50 NH2-terminal residues are conserved and are probably required for binding to the adjacent protein 36. This area is followed by more or less irregularly spaced regions of non-homology, partial homology or complete homology. The heterogeneity is most prominent in a region encompassing about 600 CO2H-terminal residues of the T2 or K3 proteins. Nevertheless, the amino acid compositions of the three proteins are very similar and all are rich in glycine. It has been found that the receptor specificities of phages K3 and T2 are determined by protein 38, a polypeptide required for the efficient dimerization of protein 37 of phage T4. Proteins 38 of phages K3 and T2 are functionally interchangeable, those of T4 and T2 or K3 are not. Proteins 37 of phages K3 and T2 possess a conserved sequence of 160 CO2H-terminal residues. This area is missing in the T4 protein. This region may serve as a binding site for polypeptides 38 of phages K3 and T2. The overall picture of the protein primary structures of the three phages strongly suggests that the evolution of genes 37, which was most likely driven by selection for variations in receptor recognition specificities, has not been a steady process but has involved loss and gain of segments of DNA.

Amino Acid Sequence↗
PubMed1994

Studies on a novel anterior cruciate ligament polyethylene fiber prosthesis: the histomorphological pattern of organization and bony anchorage of a polyethylene fiber prosthesis in the stifle of the goat.

The anterior cruciate ligament of goats was substituted by a high-tensile polyethylene fiber prosthesis. The animals were sacrificed after 6-12 months. Histologically, the implants were separated from a newly formed bony shell by a thick fibrous interface membrane, which was anchored to the bone by Sharpey-like fibers. Within the joint cavity, the implants were enclosed in thick fibrous sheaths, which were continuous with the intra-osseous interface membranes. While the inner granulomatous layer of the interface membrane extended in between the polyethylene fibrils for a short distance, the bulk of the prosthesis was poorly organized. A thick central fibrous band accompanied the intra-osseous and intra-articular portions of the implants throughout their entire lengths. Oblique fibrous tracks linked the interface membranes with the central fibrous bands. The intra-osseous tunnels were considerably expanded when compared to the initially drilled tunnels.

Animals↗
PubMed2006

Provisional anterior tooth replacement using nonimpregnated fiber and fiber-reinforced composite resin materials: a clinical report.

The loss of anterior teeth is often a serious esthetic concern. While conventional fixed partial dentures and implant-supported restorations may be the treatments of choice, nonimpregnated fibers (NFs) and fiber-reinforced composite (FRC) resins offer a conservative alternative for improving esthetics. This article describes 2 clinical situations in which NF glass ribbon and FRC were successfully used to provisionally restore anterior edentulous areas in an esthetic, functional, and timely manner.

Acrylic Resins↗
PubMed1983

Attachment of tail fibers in bacteriophage T4 assembly. Identification of the baseplate protein to which tail fibers attach.

A phage-neutralizing rabbit antiserum collected after immunization with tail-fiberless bacteriophage T4 particles was adsorbed with complete T4 phage. The resulting adsorbed serum inhibited tail fiber attachment in vitro. To identify the antigens against which this inhibitory activity was directed, blocking experiments were carried out with the adsorbed serum. Isolated complete baseplates and mutant-infected-cell extracts lacking known baseplate gene products but containing gene 9 product showed similar high levels of blocking activity. By contrast, both tail-fiberless particles lacking gene 9 product and infected-cell extracts made with gene 9 mutants showed 30-fold to 100-fold lower blocking activity. These results strongly support the conclusion that gene 9 product is the baseplate protein to which tail fibers attach.

Antigens, Viral↗
PubMed2003

Analysis of orientations of collagen fibers by novel fiber-tracking software.

Recent evidence supports the notion that biological functions of extracellular matrix (ECM) are highly correlated to not only its composition but also its structure. This article integrates confocal microscopy imaging and image-processing techniques to analyze the microstructural properties of ECM. This report describes a two- and three-dimensional fiber middle-line tracing algorithm that may be used to quantify collagen fibril organization. We utilized computer simulation and statistical analysis to validate the developed algorithm. These algorithms were applied to confocal images of collagen gels made with reconstituted bovine collagen type I, to demonstrate the computation of orientations of individual fibers.

Algorithms↗
PubMed1965

Contractility and ultrastructure in glycerol--extracted muscle fibers. II. Ultrastructure in resting and shortened fibers.

Glycerol-extracted rabbit psoas muscle fibers were examined by electron microscopy both before and after ATP-induced isotonic shortening. Ultrastructural changes were correlated with the initial sarcomere length and the degree of shortening. The ultrastructural appearance of the resting fiber at rest length was identical with that described by H. E. Huxley and Hanson. At sarcomere lengths greater than 3.7 to 3.8 micro, the A and I filaments were detached and separated by a gap. The presence of "gap" filaments was confirmed, and evidence is presented which indicates that these filaments form connections between the ends of the A and I filaments. Shortening from initial sarcomere lengths at which the filaments overlapped took place through sliding of the filaments. If shortening was initiated from sarcomere lengths at which there was a gap, a narrowing of the I band was brought about by a curling of the I filaments at the boundary between the A and I bands. No evidence could be found that the I filaments moved into the A band.

Animals↗