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PubMed1985

Comparison of labeled heat shock proteins in neuronal and non-neuronal cells of Aplysia californica.

Aplysia californica has been used to study the protein synthetic response of nervous tissue to stress induced by elevated temperatures. The abdominal and pleural ganglia as well as associated connectives were exposed to various temperatures for 30 min, labeled with [33S]methionine at room temperature, and then analyzed by sodium dodecyl sulfate gel electrophoresis. All cells examined responded to temperatures of greater than 31 degrees C by a reduction in levels of labeled actin, as well as by the enhanced labeling of proteins with apparent Mr of 70,000 and 110,000. Two-dimensional electrophoresis indicated that the molecular weight and isoelectric focusing properties are similar to the heat shock proteins (HSPs) observed in other systems. In addition to these major HSPs, heat-induced proteins with molecular weights ranging from 70,000 to 90,000 were highly labeled in the neurosecretory bag cells. Further cell type-specific differences in the protein synthetic response to elevated temperatures were revealed by quantitation of the major HSPs. Levels of labeled HSPs were significantly lower in ganglion cells as compared to the non-neuronal connective cells. In addition, the decrease in actin levels appeared to be less dramatic in the ganglion cells. Analysis of the cellular compartmentalization of HSPs suggests that both neurons and glia are capable of HSP synthesis. Studies in the squid have demonstrated that HSPs are transferred from adaxonal glia into the axoplasm (Tytell, M., S. G. Greenberg, and R. J. Lasek, unpublished observation).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[External fixator: surgical technique, pinless fixator, change in procedure].

External Fixation-Technique: The advantages of external over internal fixation are as follows: a) endosteal and periosteal blood supply is undisturbed, b) "low-tech" equipment may be used, c) secondary adjustments are possible and d) easy implant removal. These benefits however are outweighed by the main disadvantages of long term external fixation i.e. pin complications and delayed union of fractures. Better understanding of postoperative management and careful application of screws of improved design will lead to better results. Today's standard applications of external fixation for tibial fractures is a unilateral fixator, using Schanz screws. The pin-bone interface is the most critical site of all external fixation. By avoiding heat necrosis (low temperature drilling) and preventing micro motion at the pin-bone interface (by applying bending- or more recently radial-preload), pin complications such as infection and loosening can be reduced. Two Schanz screws are inserted into each main fragment and are connected with one short tube per fragment. The fracture is then reduced by using these tubes as handles. After reduction a third tube connects the first two by means of two tube-to-tube clamps. This type of fixation will easily allow for three dimensional secondary corrections of alignment. Approximately three weeks following the injury some motion at the fracture site will stimulate callus formation. This can be achieved by destabilisation, dynamisation or "active stimulation" of the fracture site [2]. Pinless fixator: The pinless external fixator holds the fragments firmly with pointed clamps that penetrate about one millimeter into cortical bone without entering and contaminating the medullary canal.(ABSTRACT TRUNCATED AT 250 WORDS)

Equipment Design↗
PubMed1993

Subcellular distribution and immunological detection of retrograde axonally transported proteins in acrylamide and diabetic neuropathies.

Neuropathies produced by both acrylamide- and streptozotocin-induced diabetes in the rat are accompanied by a deficit in the retrograde axonal transport of a defined group of proteins that can be visualized on two-dimensional polyacrylamide gels. In this work, these proteins are identified as being primarily soluble and being absent from rat brain. They are not immunologically related to the major retrogradely transported protein synaptophysin. Polyclonal antiserum to the proteins was produced in mice and used to confirm the reduction in their retrograde transport in sciatic nerve of diabetic and acrylamide-treated rats.

Acrylamide↗
PubMed1984

Isohedonic tastes support a two-dimensional hypothesis of palatability.

The hypothesis that tastes activate two systems of palatability processing was tested by examining the ingestive and aversive fixed-action patterns (FAPs) elicited by equally preferred tastes. Berridge and Grill (1983) reported that the probability of occurrence of aversive FAPs could be increased without producing a reciprocal reduction in the probability of ingestive responses. This independence of ingestion and aversion was confirmed, and it was shown that the effect extends to measures of the actual quantity, as well as the probability, of the FAPs. It was further shown that ingestive and aversive FAPs could be increased together by simultaneously increasing the sucrose and quinine concentration of a taste. Equal preference between tastes may therefore need not imply identical hedonic evaluations, but rather simply an equivalent balance between ingestive and aversive systems. These data provide support for a two-dimensional hypothesis of palatability processing.

Animals↗
PubMed2001

Reductions in neuronal and glial density characterize the dorsolateral prefrontal cortex in bipolar disorder.

BACKGROUND: Bipolar disorder (BPD) is a mental illness in which depression and mania typically alternate, and both phases can present with psychotic features. The symptomatology of BPD, therefore, resembles major depressive disorder (MDD) and schizophrenia (SCHZ), posing diagnostic dilemmas. Distinct alterations in cellular architecture of the dorsolateral prefrontal cortex distinguish SCHZ and MDD, whereas the cellular neuropathology of BPD has not been studied. METHODS: Dorsolateral prefrontal area 9 was analyzed using a three-dimensional morphometric method in postmortem brains from 10 BPD patients and 11 matched nonpsychiatric control subjects. RESULTS: Area 9 in BPD was characterized by reduced neuronal density in layer III (16%-22%) and reduced pyramidal cell density in layers III and V (17%-30%). A 19% reduction in glial density was found in sublayer IIIc coupled with enlargement and changes in shape of glial nuclei spanning multiple layers. CONCLUSIONS: The morphologic signature of BPD, i.e., decreased neuronal and glial density in association with glial hypertrophy, is distinct from previously described elevations in neuronal density in SCHZ, instead resembling the reductions in cell density found in MDD. Thus, the neuropathologic distinctions between BPD and SCHZ are indicative of separate mental illnesses, each with a unique morphologic disturbance of specific neural circuits.

Adult↗
PubMed2005

Insight into normal mitral and tricuspid annular dynamics in pediatrics: a real-time three-dimensional echocardiographic study.

BACKGROUND: Although there are animal or adult studies analyzing annular motion of the mitral valve (MV) or tricuspid valve (TV) separately, there are no data analyzing interaction between the MV and TV, or data from the pediatric population. METHODS: A total of 17 healthy children (age 3-15 years) were enrolled in this study. Using real-time 3-dimensional echocardiography, annular area, perimeter, segmental diameter, and bending angle were obtained and analyzed. RESULTS: MV area increased during systole, in contrast to TV area, which decreased. TV area demonstrated a greater reduction of lateral diameter during systole. Bending motion became most acute in early diastole, which was greater for the TV. CONCLUSIONS: MV area change differs from adults, which may be explained by a more compliant myocardium in children. Greater lateral forces on TV prevent it from becoming circular, thus, preserving valve competency. Both valves show a bending motion, which becomes most prominent during isovolumic relaxation continuing into early diastole for the TV, suggesting a relationship with torsional forces within the ventricles.

Adolescent↗
PubMed1980

Interaction between cytochrome b5 and hemoglobin: involvement of beta 66 (E10) and beta 95 (FG2) lysyl residues of hemoglobin.

In erythrocytes the reduction of oxidized hemoglobin (methemoglobin) is dependent upon an electron transport reaction between cytochrome b5 and methemoglobin. These two proteins are believed to form a complex whose bonding is principally determined by complementary charge interactions between acidic groups of cytochrome b5 and basic groups of hemoglobin. In order to refine this model, three surface lysyl hemoglobin variants--namely Hb N Baltimore beta 95 (FG2) Lys leads to Glu, Hb I Toulouse beta 66 (E10) Lys leads to Glu, and Hb I Philadelphia alpha 16 (A14) Lys leads to Glu--have been studied with respect to their reducibility and ability to bind cytochrome b5. In the two former variants, the substituted amino acids are located near the heme crevice; in the third one the substitution lies far from it. Substitutions of lysine for glutamic acid in positions beta 66 and beta 95 perturb the formation of the cytochrome b5--hemoglobin complex and result in a dramatic impairment of the cytochrome b5-mediated reduction, whereas the same mutation in position alpha 16 has no effect. We conclude that the lysine residues in positions beta 66 and beta 95 are directly involved in the binding of cytochrome b5. The three-dimensional structure of hemoglobin suggests that the cytochrome b5-binding domain of hemoglobin is constituted by four lysine residues surrounding the heme crevice in both alpha and beta chains. Similarities with other interacting hemoproteins are discussed.

Amino Acid Sequence↗
PubMed1995

Isolation, purification and structure of exochelin MS, the extracellular siderophore from Mycobacterium smegmatis.

The extracellular siderophore from Mycobacterium smegmatis, exochelin MS, was isolated from iron-deficiently grown cultures and purified to > 98% by a combination of ion-exchange chromatography and h.p.l.c. The material is unextractable into organic solvents, is basic (pI = 9.3-9.5), has a lambda max at 420 nm and a probable Ks for Fe3+ of between 10(25) and 10(30). Its structure has been determined by examination of desferri- and ferri-exochelin and its gallium complex. The methods used were electrospray-m.s. and one- and two-dimensional (NOESY, DQF-COSY and TOCSY) 1H n.m.r. The constituent amino acids were examined by chiral g.l.c analysis of N-trifluoroacetyl isopropyl and N-pentafluoropropionyl methyl esters after hydrolysis, and reductive HI hydrolysis, of the siderophore. The exochelin is a formylated pentapeptide: N-(delta-N-formyl,delta N-hydroxy-R-ornithyl) -beta-alaninyl-delta N-hydroxy-R-ornithinyl-R-allo-threoninyl-delta N-hydroxy-S-ornithine. The linkages involving the three ornithine residues are via their delta N(OH) and alpha-CO groups leaving three free alpha-NH2 groups. Although there are two peptide bonds, these involve the three R (D)-amino acids. Thus the molecule has no conventional peptide bond, and this suggests that it will be resistant to peptidase hydrolysis. The co-ordination centre with Fe3+ is hexadenate in an octahedral structure involving the three hydroxamic acid groups. Molecular modelling shows it to have similar features to other ferric trihydroxamate siderophores whose three-dimensional structures have been established. The molecule is shown to have little flexibility around the iron chelation centre, although the terminal (Orn-3) residue, which is not involved in iron binding except at its delta N atom, has more motional freedom.

Amino Acid Sequence↗
PubMed1990

A dimension reduction framework for understanding cortical maps.

We argue that cortical maps, such as those for ocular dominance, orientation and retinotopic position in primary visual cortex, can be understood in terms of dimension-reducing mappings from many-dimensional parameter spaces to the surface of the cortex. The goal of these mappings is to preserve as far as possible neighbourhood relations in parameter space so that local computations in parameter space can be performed locally in the cortex. We have found that, in a simple case, certain self-organizing models generate maps that are near-optimally local, in the sense that they come close to minimizing the neuronal wiring required for local operations. When these self-organizing models are applied to the task of simultaneously mapping retinotopic position and orientation, they produce maps with orientation vortices resembling those produced in primary visual cortex. This approach also yields a new prediction, which is that the mapping of position in visual cortex will be distorted in the orientation fracture zones.

Animals↗
PubMed1987

Arch dimensional changes during and following fixed appliance therapy.

A retrospective investigation of the study casts of 23 subjects, treated by Fixed Appliances and the extraction of four premolars, using the Reflex Metrograph showed a general trend for a reduction in mean arch dimensions both during and following treatment. An exception was demonstrated in the intercanine width, which for both arches showed slight expansion during treatment, although this was lost post-treatment in the mandibular arch while it was maintained in some cases in the maxillary arch.

Cephalometry↗
PubMed1990

A simplified normalized ejection phase index measured by Doppler echocardiography for the assessment of left ventricular performance.

Although useful for the assessment of directional changes in contractility in individual patients, resting peak aortic blood velocity is of limited value for differentiating among patients with different levels of basal cardiac function. A dimensional analysis based on fluid dynamics shows that peak aortic blood velocity is not only generated by the contracting myocardium but also reflects the convective acceleration of blood from the left ventricle to the aorta. The reduction of cross-sectional area from the midleft ventricle to the aorta at the time of peak aortic blood velocity generates the convective acceleration. Accordingly, a higher convective acceleration due to left ventricular (LV) enlargement as observed in cardiomyopathy may explain why peak aortic blood velocity can be maintained as normal although myocardial contractility is depressed. This study tested the hypothesis that peak aortic blood velocity normalized by the ratio of midleft ventricle to aortic cross-sectional areas might provide a reliable index of LV performance. Nine normal control subjects and 25 patients undergoing catheterization were studied by M-mode, 2-dimensional and Doppler echocardiography. The normalized peak velocity measured noninvasively showed a high correlation with angiographic ejection fraction (r = 0.90, p less than 0.0001). Peak aortic blood velocity and the ratio of midleft ventricle to aortic cross-sectional areas alone correlated less well with ejection fraction (r = 0.76 and r = 0.75, p less than 0.0001, respectively). Furthermore, peak aortic blood velocity showed a significant overlap between patients with normal and those with abnormal LV function, whereas normalized peak aortic blood velocity was a better discriminator.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2005

Small tip angle three-dimensional tailored radiofrequency slab-select pulse for reduced B1 inhomogeneity at 3 T.

This work presents a small tip-angle 3D tailored RF slab-select pulse for reducing the B1 field inhomogeneity at 3T. The compensated slice profile was determined from a B1 inhomogeneity map. SNR improvement and degree of artifact reduction were evaluated in a NiCl2 doped phantom and human brains. The technique was found to reduce inhomogeneities as large as 30% of the peak image magnitude in all three spatial directions in the brain using a standard head coil.

Algorithms↗
PubMedDate not supplied

Identification of mouse liver proteins on two-dimensional electrophoresis gels by matrix-assisted laser desorption/ionization mass spectrometry of in situ enzymatic digests.

A number of proteins from a silver-stained two-dimensional (2-D) electrophoresis gel of mouse liver whole-cell lysate were identified by peptide mass mapping and sequence database searching. The excised protein spots were processed by in situ reduction and alkylation, followed by Lys-C digestion. The masses of the resulting peptide mixtures were measured with a matrix-assisted laser desorption/ionization (MALDI) reflection-time-of-flight mass spectrometer. These masses were used successfully to search a protein sequence database. Optimized silver staining and digestion protocols allowed proteins to be identified routinely at the low picomole level. The high mass accuracy and resolution provided by delayed extraction were important for high specificity in the database search. Fragment ion data obtained by MALDI post-source decay (PSD) measurements not only provided confirmation of peptide identification, but could be used to identify the protein from a single peptide without spectral interpretation.

Acrylic Resins↗
PubMed2006

Reduction of soluble and insoluble iron forms by membrane fractions of Shewanella oneidensis grown under aerobic and anaerobic conditions.

The effect of iron substrates and growth conditions on in vitro dissimilatory iron reduction by membrane fractions of Shewanella oneidensis MR-1 was characterized. Membrane fractions were separated by sucrose density gradients from cultures grown with O(2), fumarate, and aqueous ferric citrate as the terminal electron acceptor. Marker enzyme assays and two-dimensional gel electrophoresis demonstrated the high degree of separation between the outer and cytosolic membrane. Protein expression pattern was similar between chelated iron- and fumarate-grown cultures, but dissimilar for oxygen-grown cultures. Formate-dependent ferric reductase activity was assayed with citrate-Fe(3+), ferrozine-Fe(3+), and insoluble goethite as electron acceptors. No activity was detected in aerobic cultures. For fumarate and chelated iron-grown cells, the specific activity for the reduction of soluble iron was highest in the cytosolic membrane. The reduction of ferrozine-Fe(3+) was greater than the reduction of citrate-Fe(3+). With goethite, the specific activity was highest in the total membrane fraction (containing both cytosolic and outer membrane), indicating participation of the outer membrane components in electron flow. Heme protein content and specific activity for iron reduction was highest with chelated iron-grown cultures with no heme proteins in aerobically grown membrane fractions. Western blots showed that CymA, a heme protein involved in iron reduction, expression was also higher in iron-grown cultures compared to fumarate- or aerobic-grown cultures. To study these processes, it is important to use cultures grown with chelated Fe(3+) as the electron acceptor and to assay ferric reductase activity using goethite as the substrate.

Aerobiosis↗
PubMed2006

Effect of weight loss on cellulite: gynoid lypodystrophy.

BACKGROUND: Gynoid lipodystrophy (cellulite) affects most women, and many seek plastic surgery consultation to improve appearance. Various products are offered, but the literature on the cause and treatment is limited. Understanding the biological and biophysical factors that affect severity may facilitate the development of effective therapies. There has been a dramatic increase in the number of people who have lost significant weight as a result of bariatric surgery or medically supervised weight programs. The effect of weight loss on cellulite severity has not been systematically studied and remains a common patient concern. The authors hypothesized that cellulite severity would decrease with weight loss and subsequent decrease in subcutaneous fat in most subjects. METHODS: The authors examined the cellulite changes in female subjects who were enrolled in medically supervised weight loss programs using quantitative surface roughness by three-dimensional laser surface scanning, tissue composition by dual energy x-ray absorptiometry, dermal-subcutaneous structure with three-dimensional ultrasound, and tissue elasticity with biomechanical measurements. RESULTS: The majority of subjects had an improvement in cellulite with weight loss, but the condition worsened for others. Improvement was associated with significant reductions in weight and percentage of thigh fat, significantly higher starting body mass index, and significantly greater initial severity. Cellulite worsened with a significantly smaller starting body mass index, smaller reductions in weight accompanied by no change in percentage of thigh fat, and significant increases in tissue compliance. CONCLUSIONS: Cellulite is a complex condition, and treatments such as weight loss have variable effects on the improvement or worsening of this condition. Additional studies are required to understand how the factors that influence and modulate cellulite severity, particularly those at the level of the subcutaneous tissue septa, can be manipulated to improve this condition.

Absorptiometry, Photon↗
PubMed2006

Mapping corpus callosum deficits in autism: an index of aberrant cortical connectivity.

BACKGROUND: Volumetric studies have reported reductions in the size of the corpus callosum (CC) in autism, but the callosal regions contributing to this deficit have differed among studies. In this study, a computational method was used to detect and map the spatial pattern of CC abnormalities in male patients with autism. METHODS: Twenty-four boys with autism (aged 10.0 +/- 3.3 years) and 26 control boys (aged 11.0 +/- 2.5 years) underwent a magnetic resonance imaging (MRI) scan at 3 Tesla. Total and regional areas of the CC were determined using traditional morphometric methods. Three-dimensional (3D) surface models of the CC were also created from the MRI scans. Statistical maps were created to visualize morphologic variability of the CC and to localize regions of callosal thinning in autism. RESULTS: Traditional morphometric methods detected a significant reduction in the total callosal area and in the anterior third of the CC in patients with autism; however, 3D maps revealed significant reductions in both the splenium and genu of the CC in patients. CONCLUSIONS: Statistical maps of the CC revealed callosal deficits in autism with greater precision than traditional morphometric methods. These abnormalities suggest aberrant connections between cortical regions, which is consistent with the hypothesis of abnormal cortical connectivity in autism.

Adolescent↗
PubMed2004

Star-Shaped nanomolecules based on p-phenylene sulfide asterisks with a persulfurated coronene core.

Persulfurated p-phenylene sulfide (PPS) molecular asterisks (6-9) from "generations" 1 to 4 were efficiently prepared. They represent a new class of electron-accepting PPS star-shaped nanomolecules. Spectroelectrochemistry, cyclic voltammetry and UV-visible studies were performed for the asterisks and for functionalized p-phenylene sulfide oligomers (1-4). These data confirmed for the first time that an electronic delocalization through the whole asterisk molecule exists in the radical anionic or dianionic forms, in spite of divalent sulfur bridges between phenyl groups. They could be seen as globular spheres with a three-dimensional electronic network and delocalization. Electrochemical studies indicated that sulfur substituents strongly stabilize the reduced form of the asterisk relative to coronene itself, and the ease of reduction depends on the PPS chain length.

Journal Article↗
PubMed2001

Mitotic index and ki-67 nuclear antigen labeling index as predictors of chemotherapy response in uterine cervical carcinoma.

OBJECTIVE: The aim of this study was to determine if the mitotic index (MI) and the Ki-67 nuclear antigen labeling index (Ki67LI) obtained from biopsy specimens could be used as predictors of chemotherapy response in uterine cervical carcinomas. METHODS: Six patients with squamous cell carcinoma who received neoadjuvant chemotherapy before radical surgery were entered into the study. The MI and the Ki67LI were evaluated using hematoxylin and eosin (H&E)-stained and immunostained slides before and after chemotherapy. Tumor size was measured three-dimensionally by magnetic resonance imaging. We compared the values of MI and Ki67LI with changes in tumor size. RESULTS: The cases were classified according to the percentage reduction in tumor mass: one case showed a marked response (98%), four showed a moderate response (53-78%), and one showed a slight response (approximately 0%). In the case with a marked response, the MI values before chemotherapy and 3 and 7 days after chemotherapy were 15, 2, and 0, respectively. The corresponding Ki67LI values were 51, 16, and 0, respectively. In the moderate response cases, the corresponding MI values before and 3 and 7 days after chemotherapy were 3.9-13.6, 0.8-1.6, and 1.6-4.0, respectively. The Ki67LI was 21.8-44.2 before chemotherapy, with two cases increasing and two decreasing at 7 days after chemotherapy. In the case showing a slight response, the MI values before chemotherapy and 3 and 7 days after chemotherapy were 0.5, 0.8, and 1.0, respectively. The Ki67LI was 4.0 before chemotherapy and increased slightly to 6.0 at 7 days after chemotherapy. CONCLUSIONS: In six cases examined, high MI and Ki67LI values before chemotherapy and a marked decrease in MI shortly after chemotherapy appeared to be predictors of good neoadjuvant chemotherapy response in uterine cervical carcinomas.

Adult↗