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At least 271 records · Page 15Linked to original sources
PubMed2003

Production of high-quality particulate methane monooxygenase in high yields from Methylococcus capsulatus (bath) with a hollow-fiber membrane bioreactor.

In order to obtain particulate methane monooxygenase (pMMO)-enriched membranes from Methylococcus capsulatus (Bath) with high activity and in high yields, we devised a method to process cell growth in a fermentor adapted with a hollow-fiber bioreactor that allows easy control and quantitative adjustment of the copper ion concentration in NMS medium over the time course of cell culture. This technical improvement in the method for culturing bacterial cells allowed us to study the effects of copper ion concentration in the growth medium on the copper content in the membranes, as well as the specific activity of the enzyme. The optimal copper concentration in the growth medium was found to be 30 to 35 micro M. Under these conditions, the pMMO is highly expressed, accounting for 80% of the total cytoplasmic membrane proteins and having a specific activity as high as 88.9 nmol of propylene oxide/min/mg of protein with NADH as the reductant. The copper stoichiometry is approximately 13 atoms per pMMO molecule. Analysis of other metal contents provided no evidence of zinc, and only traces of iron were present in the pMMO-enriched membranes. Further purification by membrane solubilization in dodecyl beta-D-maltoside followed by fractionation of the protein-detergent complexes according to molecular size by gel filtration chromatography resulted in a good yield of the pMMO-detergent complex and a high level of homogeneity. The pMMO-detergent complex isolated in this way had a molecular mass of 220 kDa and consisted of an alphabetagamma protein monomer encapsulated in a micelle consisting of ca. 240 detergent molecules. The enzyme is a copper protein containing 13.6 mol of copper/mol of pMMO and essentially no iron (ratio of copper to iron, 80:1). Both the detergent-solubilized membranes and the purified pMMO-detergent complex exhibited reasonable, if not excellent, specific activity. Finally, our ability to control the level of expression of the pMMO allowed us to clarify the sensitivity of the enzyme to NADH and duroquinol, the two common reductants used to assay the enzyme.

Amino Acid Sequence↗
PubMed1998

Electron microscopic investigation of sulcus vocalis.

This investigation was carried out to determine the histopathologic findings of sulcus vocalis in two human adult larynges. Observations were made by light and transmission electron microscopy. The results are summarized as follows. Sulcus was confined to the squamous epithelium area. The basement membrane thickness increased at the sulcus. The sulcus was situated in the superficial layer of the lamina propria, which was thin around the bottom of the sulcus. Collagenous fibers were dense, and fibrous long-spacing collagen was seen around the bottom of the sulcus. Elastic fibers decreased in number and were composed predominantly of microfibrils and reticular amorphous substances. In the maculae flavae, the fibroblasts were decreased in number and degenerated. Collagenous and elastic fibers, synthesized by fibroblasts in the maculae flavae, were decreased. There were many abnormal elastic fibers in the maculae flavae. The quality and quantity of the fibrous components were changed in the mucosa of sulcus vocalis, owing in part to dysfunction of the fibroblasts and abnormal fibrogenesis in the maculae flavae.

Basement Membrane↗
PubMed2002

Least-mean-squares phase unwrapping by use of an incomplete set of residue branch cuts.

A new technique for the least-mean-squares (LMS) phase-unwrapping method is developed that incorporates the concept of branch cuts between phase singularities (residues), which are usually associated with the path-following gradient integration technique. These branch cuts are introduced by decomposition of the least-mean-squares unwrapped phase into two separate components. The first results from the transverse part of the wrapped phase gradient, which is induced by residues of the original phase, and the second component is due to a potential component, independent of the residues. This decomposition allows the reconstruction of phase patterns with a high level of accuracy and consistency with the initial (wrapped) phase, even when only partial knowledge of the placement of branch cuts between residues is available. We show how the residue-induced phase, ignored by conventional LMS phase estimators, is reconstructed for a given boundary-value problem. The method is illustrated with interferometric quality-control measurements of optical fiber-connector terminations and also with synthetic aperture radar interferometry. These experiments demonstrate the high accuracy of the method in practical situations in which only a limited number of branch cuts are available.

Journal Article↗
PubMed2002

Method for evaluating optical characteristics of endoscopes for recording fluorescence-related cardiac electrical activity.

Nondestructive methods were used to evaluate marketed fiber-optic endoscopes (intended for simple viewing) for fluorescence recording. Our application is for optical recording from the heart. For one angioscope, we measured a focal length of 0.33 mm, a field of view of 45 degrees, an aperture of 0.26 mm, and an efficiency of 43%. We calculated that the angioscope would give a signal-to-noise ratio of 1.0 for a cardiac action potential, if its field of view were divided into a nine-pixel array (for safe continuous illumination). Our methods are useful in designing and evaluating fluorescence fiber-optic systems with superior signal quality and spatial resolution.

Electrophysiology↗
PubMed1993

Comparison of whole, raw soybeans, extruded soybeans, or soybean meal and barley on digestive characteristics and performance of weaned beef steers consuming mature grass hay.

Two experiments were conducted to compare whole, raw soybeans (WSB), extruded soybeans (ESB), and soybean meal+barley (SBM+BAR) as supplemental protein sources for growing beef steers consuming low-quality, mature grass hay (6.5% CP). In Exp. 1, a 23-d digestion study, four ruminally cannulated steers were assigned to the following treatments in a 4 x 4 Latin square design: 1) control, no supplement; 2) 1.5 kg.animal-1.d-1 of WSB; 3) 1.36 kg.animal-1.d-1 of ESB; and 4) 1.48 kg.animal-1.d-1 of 62%:38% SBM+BAR. Apparent DM digestibility was increased by supplementation (P < .10), but NDF digestibility was not changed (P > .10). No differences in digestibility were observed among supplement treatments (P > .10). In situ rate and extent of supplement CP disappearance in Dacron bags did not differ among supplements (P > .10), but extent of DM disappearance was greater for WSB than for ESB (P < .10). In situ rate of forage NDF disappearance was decreased by protein supplementation (P = .10). In Exp. 2, 40 Polled Hereford and Red Angus x Simmental weanling steer calves were stratified by weight (average BW, 250 kg) and allotted randomly to one of two replications of the four treatments used in Exp. 1 (eight pens, five animals per pen). Forage DMI was not affected by treatment (P > .10). Average daily gain and feed efficiency were increased by supplementation (P < .05). Supplement source had no effect on intake or ADG (P > .10), but ESB tended to exhibit better feed efficiency than WSB (P = .10). In conclusion, WSB and ESB seem to be as effective as SBM+BAR protein supplements for growing beef cattle. In addition, WSB and ESB, at the levels used in these experiments, can be incorporated into diets for cattle consuming low-quality roughage without deleterious effects on fiber digestion or subsequent performance.

Ammonia↗
PubMed1989

Dietary management of geriatric diabetes.

The most important dietary precept for elderly patients with diabetes mellitus is the maintenance of desirable body weight. Weight reduction is imperative for the obese. It is now proposed that the diet prescribed contain predominantly carbohydrate (50 to 60% of total calories) and that the carbohydrates be primarily complex and rich in fiber. Protein should be of high quality, but never in excess. A diet low in saturated fats and cholesterol and proportionately higher in polyunsaturated and monounsaturated fats seems prudent in view of the accelerated incidence of macrovascular disease in this population. Lipid profiles should be carefully monitored, and carbohydrate intake may need to be limited if hypertriglyceridemia is present. Vitamin and mineral supplements may be desirable. It is important to understand that the dietary guidelines for diabetic patients discussed in this article are not fundamentally different from those for any other person desiring a healthy diet. The nutritional program outlined is a good program for everyone, and the entire family is encouraged to participate in the meal planning and preparation involved.

Aged↗
PubMed1987

On a neural mechanism for cortical processing of taste quality in the rat.

The responses of 31 chorda tympani fibers and 47 cortical neurons were recorded in response to 6 concentrations of NaCl, and single concentrations of sucrose, HCl, and quinine hydrochloride solutions applied to the anterior portion of the tongue in rats. The neural responses were analyzed in terms of the two hypotheses of quality coding: across-neuron response pattern and across-region response pattern notions. In a behavioral experiment, animals were given a conditioned taste aversion to one of 5 concentrations of NaCl solution by pairing it with a gastrointestinal illness caused by i.p. injection of 0.15 M LiCl. Behavioral taste profiles were constructed for each stimulus from the suppression of drinking, which indicates the extent of generalization of aversion to each of the 4 basic taste stimuli. Among the two neural analyses employed for the chorda tympani and cortical units, across-region correlation coefficients for cortical neurons that were derived from the across-region response pattern theory showed the highest correlation (r = 0.89) with the behavioral suppression rates. Across-neuron correlation coefficients in the chorda tympani fibers also showed a good correlation (r = 0.81) with the behavioral data. However, the taste profile for 1.0 M NaCl in chorda tympani fibers was very similar to that for the lower concentrations of NaCl, in spite of the suggestion from the behavioral experiment and the neural analyses of cortical responses that 1.0 M NaCl has HCl and quinine components besides the NaCl component. The present result confirmed the idea that processing of taste information in the cortex involves differences in both response magnitude across neurons and the spatial localization of those neurons.

Animals↗
PubMed1999

[Histochemical and morphometric studies of the musculature of the forelimb of sheep with reference to its function. 2. Flexor and extensor of carpal and toe joints].

Muscle tissue was obtained from eight forearm muscles of six male sheep (180 days old) and stained for NADH tetrazolium oxidoreductase and myofibrillar ATPase after preincubation at pH 4.3. The fiber diameter and the percentage were determined of three fiber types: slow twitch oxidative (STO), fast twitch oxidative (FTO) and fast twitch glycolytic fibers (FTG). The extensor carpi radialis muscle had the lowest percentage of STO fibers. It is a fast extensor of the carpal joint. The superficial digital flexor muscle (FS) is located in the superficial region of the forearm has shown the highest percentage of STO fibers (50%). These fibers were also considerable larger (57 microns) than the STO fibers of the deep digital flexor muscle (39 microns). The FS supports the elbow joint extensors in the fixation of the elbow joint during the standing position (static work) and flexes the digital joints in motion (dynamic work). At first muscle function decides the quality and the quantity of the muscle fibers. Then other factors, e.g. capillarization, determine the distribution of fiber types. Muscles which have to work static-tonically require a higher content of large slow twitch fibers regardless of whether these muscles are located close to the limb axis or in the periphery. They resist lastingly gravity. Thus they are antigravity muscles. In the forearm they are the superficial digital flexor muscle, flexor carpi ulnaris muscle, and extensor carpi ulnaris muscle, which always have more than 30% STO-fibers.

Adenosine Triphosphatases↗
PubMed2004

Root apex sealing with different filling materials photopolymerized with fiber optic-delivered argon laser light.

The present study evaluates the seal quality in the apex delta of uniradicular teeth filled with light-cured materials (calcium hydroxide, glass ionomer, and Flow-Fill Magic composite). A total of 45 roots prepared by the endo PTC/Dakin technique were used. All sample restorations were light-cured with 488-nm argon laser light. A 200-microm optical fiber introduced into the root canal delivered 100 mW of light power to the filler material. The fiber tip was positioned 5 mm away from the apex. Light was applied for 20 s. After curing, the samples were immersed in a methylene blue solution for 24 h. Then the samples were cut longitudinally and analyzed under a stereoscopic microscope for dye infiltration. For the sake of comparison, an additional group of ten samples submitted to conventional treatment with EndoREZ root canal sealer was also analyzed. The samples sealed with calcium hydroxide or with the glass ionomer presented less dye infiltration, as compared to those sealed with the Flow-Fill Magic composite. All products activated by fiber optic-delivered light showed superior sealing quality when compared with the self-activated EndoREZ sealer.

Analysis of Variance↗
PubMedDate not supplied

Effects of immobilization on cartilage formation after periosteal grafting in the rabbit stifle.

Autogenous periosteal grafts were harvested and placed in the trochlear grooves of the stifles of 32 rabbits. Postoperative immobilization periods of 0, 7, and 14 days were compared. Grafted areas were evaluated for gross appearance, histologic morphology, attachment of cartilage to subchondral bone, cartilage depth, chondrocyte density, proteoglycan presence, collagen fiber orientation, and mitotic activity. Nonimmobilized stifles had increased gross coverage of subchondral bone, better histologic quality, increased safranin O stain uptake, and more normal collagen fiber orientation at 60 days than stifles immobilized for 7 ir 14 days. Postoperative immobilization did not affect attachment of the graft to the subchondral bone.

Animals↗
PubMed1995

New approach to percutaneous muscle biopsy in dogs.

The size and quality of muscle specimens obtained by use of a percutaneous biopsy technique were studied. All biopsies were performed under local anesthesia, using an 11-gauge biopsy needle. The mean +/- SEM size of specimens obtained from 128 biopsies of the semitendinosus muscles of 16 Alaskan Huskies was 23.8 +/- 4.4 mg. All biopsy specimens were of sufficient quality to permit histochemical differentiation of the fiber types by use of myosin ATPase staining. An additional 8 biopsy specimens were obtained from 1 dog and analyzed for muscle glycogen content. These specimens contained 50.6 +/- 7.2 mmol of glucose/kg of muscle wet weight. This modified biopsy procedure was free of notable complications, and repeatable use produced specimens of adequate size and quality for histologic and biochemical analysis. It is concluded that this procedure is a safe and reliable alternative to open biopsy for diagnosis and management of neuromuscular, metabolic, and nutritional myopathies.

Animals↗
PubMed2001

[Alterations of the form of M-response in polyneuropathies of different genesis].

The aim of the study was to identity main types of alterations in the form of M-responses in patients with primary axonal and demyelinating polyneuropathies (PNP). Clinical and electroneuromyographic examination was performed in 227 patients aged 15-72 years with alcoholic (axonal) and inflammatory demyelinating PNP. M-response was registered from the abductor pollicis brevis, abductor digitus minimum, short extensor of the hallux, and abductor hallucis during stimulation of the motor fibers of median, ulnar, tibial, peroneal nerves using superficial registration electrodes. The basis for selection of altered types of M-responses was the analysis of the following criteria: a spatial correlation of the positive and negative picks; presence of the additional crooks, turns and phases on M-responses; location of these changes on the curve. 5 types of M-response alterations were singled out. The first three types were revealed in patients with alcoholic PNP and two other types--in patients with inflammatory demyelinating PNP. These 5 types of the changes in M-responses reflect the degree of desynchronization in coming of the impulses to muscular fibers. Classification proposed allows to improve a quality of both diagnosis and control of therapy in patients with PNP of different genesis.

Adolescent↗
PubMed1991

Nutritional benefits of soy protein and soy fiber.

Soy protein and soy fiber are common ingredients in many foodstuffs. Various kinds of soy protein, including soy flour, soy-protein concentrate, and isolated soy protein, are currently used in human foods. Soy proteins are used in infant formulas and enteral nutrition products, as ingredients in meat products, and as protein supplements. Although it is a plant protein, the protein quality of soy protein is excellent. Soy fiber is used in enteral nutrition products and some bakery goods. Research shows that soy fiber provides the important health benefits usually associated with dietary fiber, including improved laxation and cholesterol-lowering ability. This review provides background information on soy protein and soy fiber and their use in human foods.

Diabetes Mellitus↗
PubMed2006

Coherent anti-Stokes Raman scattering imaging with a laser source delivered by a photonic crystal fiber.

We demonstrate laser-scanning coherent anti-Stokes Raman scattering (CARS) imaging with two excitation laser beams delivered by a large-mode-area photonic crystal fiber. The group-velocity dispersion and self-phase modulation effects are largely suppressed due to the large mode area of the fiber and the use of picosecond pulses. The fiber delivery preserves the signal level and image spatial resolution well. High-quality images of live spinal cord tissues are acquired using the fiber-delivered laser source. Our method provides a basic platform for developing a flexible and compact CARS imaging system.

Equipment Design↗
PubMed1999

[Brief history of recent hemp cultivation in Switzerland and subsequent medico-legal problems resulting from hemp cultivation].

In March 1995, a decision about cultivation of cannabis was issued by the Swiss Federal Offices of Public Health, Police and Agriculture in order to satisfy the growing interest of farmers and other people in hemp farming. It pointed out that 1)... each hemp plant contains THC and must be therefore considered a drug, 2)... no permission is required for those who grow hemp without the intention to produce drugs ... meaning that the choice of the plant variety was not restricted to those which are characterized by a low THC concentration and grown in a few countries belonging to the European Union. Claiming that natural hemp must contain significant amounts of THC and thanks to the Swiss legislation, areas dedicated to hemp cultivation develop considerably. Most hemp plants which are submitted to our laboratories by the police for THC quantification belong to the drug-type. Nowadays, a great deal of goods (food and beverages, cosmetics, drugs) made of hemp are marketed in Switzerland. Strong suspicions exist however that several of these products could be used as a screen for the illegal market of cannabis. For instance, despite financial support from the state, fiber hemp cultivation remains unsuccessful. No advantage with regard to seed productivity, edible seed and essential oils qualities and yields have been found for drug hemp over fiber hemp by agricultural research stations up to now. Several clues about the possible illicit use of hemp goods rich in THC, especially hemp tea made of flower tops and "therapeutic" pillows filled with cannabis exist. Recently, two Federal edits were issued in order to restrict the selling of hemp seedlings and of hemp foods and beverages to those containing only low amounts of THC. However, the marketing of hemp plants used for decorating remains free partly explaining the recent success of these "beautiful" plants. Broadly speaking, the Swiss and European legislations about hemp have approached mutually during the last years.

Agriculture↗
PubMed2003

Assessment of low back muscle fatigue by surface EMG signal analysis: methodological aspects.

This paper focuses on methodological issues related to surface electromyographic (EMG) signal detection from the low back muscles. In particular, we analysed (1) the characteristics (in terms of propagating components) of the signals detected from these muscles; (2) the effect of electrode location on the variables extracted from surface EMG; (3) the effect of the inter-electrode distance (IED) on the same variables; (4) the possibility of assessing fatigue during high and very low force level contractions. To address these issues, we detected single differential surface EMG signals by arrays of eight electrodes from six locations on the two sides of the spine, at the levels of the first (L1), the second (L2), and the fifth (L5) lumbar vertebra. In total, 42 surface EMG channels were acquired at the same time during both high and low force, short and long duration contractions. The main results were: (1) signal quality is poor with predominance of non-travelling components; (2) as a consequence of point (1), in the majority of the cases it is not possible to reliably estimate muscle fiber conduction velocity; (3) despite the poor signal quality, it was possible to distinguish the fatigue properties of the investigated muscles and the fatigability at different contraction levels; (4) IED affects the sensitivity of surface EMG variables to electrode location and large IEDs are suggested when spectral and amplitude analysis is performed; (5) the sensitivity of surface EMG variables to changes in electrode location is on average larger than for other muscles with less complex architecture; (6) IED influences amplitude initial values and slopes, and spectral variable initial values; (7) normalized slopes for both amplitude and spectral variables are not affected by IED and, thus, are suggested for fatigue analysis at different postures or during movement, when IED may change in different conditions (in case of separated electrodes); (8) the surface EMG technique at the global level of amplitude and spectral analysis cannot be used to characterize fatigue properties of low back muscles during very low level, long duration contractions since in these cases the non-stable MU pool has a major influence on the EMG variables. These considerations clarify issues only partially investigated in past studies. The limitations indicated above are important and should be carefully discussed when presenting surface EMG results as a means for low back muscle assessment in clinical practice.

Adult↗
PubMed2003

Analysis of type I collagen in the parametrium of women with and without uterine prolapse, according to hormonal status.

The content and quality of type I collagen in the parametrium of women with and without uterine prolapse was evaluated. Forty-four consecutive patients were selected and divided into two groups: A, 21 women without uterine prolapse, and B, 23 with uterine prolapse. Patients in group A had uterine leiomyoma and were submitted to abdominal hysterectomy; in those from group B, vaginal hysterectomy was performed for correction of the uterine prolapse. During surgery, fragments of the parametrium were removed and processed for immunohistochemical analysis using polyclonal antibodies for type I collagen. A system of computerized digital imaging analysis was used for the quantification of collagen fibers. There was no difference between collagen content in patients either with or without prolapse, nor between pre- and postmenopausal women with prolapse. A modification of the quality of the collagen fiber was observed, it being longer and more compact in the group without uterine prolapse. In contrast, in the group with prolapse, the fibers were shorter and thinner and areas with large spaces between fibers were found at several points of the parametrium. The conclusion was that patients with uterine prolapse have the same type I collagen content as those without, but the quality of the fiber is modified. The hormonal status also did not affect collagen content.

Adult↗
PubMed1984

Tendon and ligament prostheses.

The topic of artificial tendons and ligaments for the foot and ankle has been investigated. Close attention has been given to three implants, the Silastic-rod implant, the carbon-fiber implant, and Marlex mesh. A brief historical background was given to the development of the lateral ankle reconstructive procedures and to the development of the individual artificial prostheses. The biologic reactions produced by the implants have been presented. Carbon-fiber implants and Marlex mesh induce a fibrous growth that produces a neotendon or neoligament, depending on their use. Silastic-rod implantation establishes a hollow tube with qualities very similar to the normal tendon sheath. Carbon fiber and Marlex mesh are directly implanted and used as a temporary tendon or ligament. During this time, they act as a scaffold on which the new tendon or ligament is formed. Silastic-rod implants are incorporated into a two-stage tendon-graft procedure. The Silastic rod is used during stage one to develop a new tendon sheath. Placement of an autologous tendon within the newly formed sheath occurs in stage two. Details of the actual procedure have been presented. Any tendon used in the transfer should be of similar strength with similar expansive qualities. These implants have many potential uses in podiatry. They are particularly useful in trauma cases and patients that present with ankle instability. Research pertaining to the development of an ideal suture and anastomosis technique is still needed.

Ankle↗