bluuebunny/crossref_metadata_2025 huggingface dataset:
Upper and lower body functional asymmetries in the newborn: Do they have the same lateral biases?
Authors: Domellöf Erik , Hopkins Brian , Rönnqvist Louise
Published: February 2005

It is still an open question as to whether functional asymmetries in the human newborn derive from a single lateralized system or multiple subsystems based on different neural mechanisms. In the present study, asymmetries in head turning were compared to those in leg movements during stepping and placing, with the latter also being related to differences in leg mass. The effects of an active versus an inactive state or condition were examined for all three behaviors. No overall lateral biases were found for head turning or for the first foot to move in stepping and placing, and there were no concordances among them; however, there was an asymmetry in that the left foot had a shorter onset latency when compared to the right foot for both stepping and placing. Findings are discussed in terms of what they imply about underlying neural systems that have a bearing on expressions of newborn laterality, and also with regard to the impact of methodological differences in this area of study. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46: 133–140, 2005.
Ontogeny of the transition from killer to caregiver in dwarf hamsters (Phodopus campbelli) with biparental care
Authors: Vella Emily T. , Evans Christopher C. D. , Ng Michelle W. S. , Wynne‐Edwards Katherine E.
Published: February 2005

Biparental Phodopus campbelli and uniparental P. sungorus juvenile litters (2 males, 2 females) both consumed amniotic fluid and placenta during the birth of younger siblings. Three days later, P. campbelli juveniles were most responsive to a displaced younger sibling. Thus, P. campbelli are responsive to pups as juvenile alloparents and as new parents; however, at intervening ages, infanticidal attack (bite) was seen. At 5, 7, 9, 11, or 13 weeks of age, male and female P. campbelli were given a 5‐min test with an unrelated, 3‐day‐old, anesthetized pup. Females attacked more often than males, yet pup‐retrieval rates did not differ. Female aggression increased with age and was replaced by retrieval behavior 3 days after parturition. Male attack ceased after a birth, but parental behavior did not increase, remaining below the rate for new fathers tested with their own awake pup. Over repeated testing, behavior in one test did not predict behavior in another. Transitions from caregiving alloparent to infanticidal adult and back to parental care were clear in females, but less discrete with this stimulus paradigm in these highly paternal males. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46: 75–85, 2005.
Relation of neonatal iron status to individual variability in neonatal temperament
Authors: Wachs Theodore D. , Pollitt Ernesto , Cueto Santiago , Jacoby Enrique , Creed‐Kanashiro Hilary
Published: February 2005

The relation between indices of neonatal iron status and individual differences in neonatal temperament were investigated in a sample of 148 low‐income Peruvian women and their newborn infants. Using cord blood, at birth we obtained measures of neonatal ferritin, serum iron, and hemoglobin. While neonates were still in the hospital, their behavior during a structured anthropometry examination was videotaped and subsequently coded on four temperament dimensions: activity level, negative emotionality, alertness, and soothability. The same dimensions were coded using a videotape obtained during a subsequent visit to the neonates' homes. Results indicated that lower levels of neonatal hemoglobin and serum iron were related to higher levels of negative emotionality and to lower levels of alertness and soothability. A similar pattern was found for ferritin, but only for females. For the most part, relations between neonatal iron measures and neonatal temperament were linear, operating across the full range of iron values. Our pattern of iron–temperament results could not be attributed to variation in family demographics, low birth weight, gestational age, maternal dietary intake, or markers of neonatal illness and maternal diabetes. Our findings are consistent with prior research with older infants relating iron deficiency to temperament. These results support the importance of increased research on the early functional–behavioral consequences of individual differences in iron status as well as on the mechanisms that underlie such consequences. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46: 141–153, 2005.
Chicken genome: New tools and concepts
Authors: Dequéant Mary‐Lee , Pourquié Olivier
Published: February 2005

Last spring, the Second International Chicken Genome Workshop was held at the Stowers Institute for Medical Research, less than 2 months after the first draft of the chicken genome was publicly released in March, 2004. This major event was highly anticipated by the chicken community, because of the invaluable resources that would be newly provided. In addition, from an evolutionary standpoint, birds are the species most closely related to mammals, whose genome has been sequenced. The meeting gathered both agricultural and academic chicken communities and provided the opportunity to discuss the status of the chicken genome sequencing, the preliminary analysis of the chicken genome sequences freshly available, and the impact on avian genetic tools. Developmental Dynamics 232:883–886, 2005. © 2005 Wiley‐Liss, Inc.
Determination of Uric Acid and Norepinephrine by Chitosan‐Multiwall Carbon Nanotube Modified Electrode
Authors: Lu Guanghan , Jiang Lingyan , Song Feng , Liu Chuanyin , Jiang Liping
Published: February 2005

A novel chemically modified electrode based on the chitosan‐multiwall carbon nanotube (MWNT) coated glassy carbon electrode (GCE) is described, which exhibited an attractive ability to determine uric acid (UA) and norepinephrine (NE) simultaneously. The responses of UA and NE merged into a large peak at a bare GCE, but yielded two well‐defined oxidation peaks at the chitosan‐MWNT modified GCE (MC/GCE). The experimental parameters were optimized, and a direct electrochemical method for the simultaneous determine for UA and NE is proposed. The MC/GCE showed good sensitivity, selectivity and stability.
Genetic Algorithm Based Potential Selection in Simultaneous Voltammetric Determination of Isoniazid and Hydrazine by Using Partial Least Squares (PLS) and Artificial Neural Networks (ANNs)
Authors: Majidi Mir Reza , Jouyban Abolghasem , Asadpour‐Zeynali Karim
Published: February 2005

The voltammetric behavior of isoniazid and hydrazine at an overoxidized polypyrrole modified glassy carbon electrode has been investigated. The obtained cyclic voltammograms showed that their oxidation peaks were overlapped and it is difficult to determine them individually from a mixture without separation. To overcome this limitation, a procedure was proposed for resolution of overlapped voltammetric signals from mixtures of isoniazid and hydrazine. In this procedure, genetic algorithm was used for the selection of potentials for partial least squares. A feed forward artificial neural network with back propagation error algorithm was used to process the nonlinear relationship between currents and concentrations of hydrazine and isoniazid. The proposed method was suitable for determination of isoniazid in pharmaceutical tablets and detection of hydrazine impurities in the same samples.
Slash expenses with consumer‐driven health plans
Authors: Goldberg Stephen R. , Lindquist Stanton C. , Danko Dori
Published: February 2005

Health‐care costs continue to soar, affecting firms of all sizes. Companies need cost relief. So, they're now looking at consumer‐driven healthcare plans instead of traditional ones. How do these innovative new plans work? What are their advantages and disadvantages? And what's the best way to implement them? The authors have some answers. © 2005 Wiley Periodicals, Inc.
How SPC can help cut costs
Authors: Roth Harold P.
Published: February 2005

Many companies use Statistical Process Control (SPC) charts to manage and control quality. But they also provide valuable signals about why your company incurs costs—and reveal opportunities to cut costs. So SPC can help you implement many different types of cost‐reduction strategies. The author explains the basics of SPC and shows how you can use it to spot opportunities to reduce costs. © 2005 Wiley Periodicals, Inc.
Strontium‐calcium transport across the gill of rainbow trout, (Salmo gairdnerii)
Authors: Schiffman R. H.
Published: February 2005

This study was performed using radioactive isotopes of calcium and strontium as tracers in a perfused gill preparation. There were two levels in the uptake rates for strontium and calcium: a passive rate of 0.5 × 10−7 cm/sec, and 1.8 × 10−7 cm/sec, respectively, and a tenfold higher energy dependent rate of 5.1 × 10−7 cm/sec for strontium and 17 × 10−7 cm/sec for calcium. There was no evidence of discriminatory interaction between calcium and strontium at the passive levels of transport. Strontium was found to substitute for calcium at the active transport levels only if the calcium concentration of the environmental water was below approximately 0.1 mM Ca++/1.

The rate of calcium and strontium loss from the gill was estimated as about 20 times faster than the influx rates. This caused the postulation that the net transfer of calcium ions across the gill could change, dependent upon the degree of saturation of the calcium‐binding sites within the fish.
The pathogenicity to mice of three variants of Mengo encephalomyelitis virus
Authors: Colter John S. , Campbell James B. , Hatch Lorne R.
Published: February 2005

The distribution of infectious virus particles in various tissues of the mouse was determined following the intraperitoneal injection of three plaque variants of Mengo encephalomyelitis virus. When lethal doses were administered, virus appeared first in the spleen and lymph nodes (suggesting that these are the primary target organs for the agents), followed by its appearance in spinal cord and brain, in which tissues the infectious titers increased progressively until the death of the animals. Low levels of virus were sometimes found in lung, heart and kidney at 24–48 hours post‐challenge, but disappeared from these tissues at later times. Virus was never detected in blood or liver, suggesting that the virus moves throughout the animal by way of the lymphatic system. When sub‐lethal doses of virus were injected, it was detectable only in spleen and lymph nodes, and disappeared from these tissues by 8–9 days post‐challenge.

The LD50's for the three variants when injected by both the intraperitoneal and intracerebral routes were determined. The I.P.‐LD50's for the L (large plaque former), M (medium plaque former) and S (minute plaque former) variants in 14–16 gm mice were found to be 1, 1–5 × 104 and 2–10 × 104 p.f.u.'s, respectively. The I.C.‐LD50's were essentially the same (1–5 p.f.u.'s) for all three variants. The possibility that the differences in the I.P.‐LD50's may be due to differences in the abilities of the variants to stimulate interferon production or in their sensitivities to its antiviral action is discussed.
Electrotonic spread of current in cultured chick heart cells
Authors: Lehmkuhl D. , Sperelakis Nick
Published: February 2005

Following trypsin dispersion, isolated single cells reassembled into monolayer communities categorized as strands and sheets. Two microelectrodes were mounted in bridge circuits so that current pulses could be passed through one electrode while simultaneously recording membrane potentials at both electrodes. The electrotonic spread of current was measured as a change in membrane potential (usually at electrode 2) at various distances from the site of current injection (usually at electrode 1). Most cells were driven by transmission of excitation from contiguous cells. Criteria which helped to determine when both electrodes impaled the same cell included: (a) a sharp diminution of the resting potential recorded by the first electrode to a common intermediate level following insertion of the second electrode and (b) simultaneous and congruous subthreshold changes in membrane potential. The voltage/current relationship measured at electrode 1 was linear and had a mean slope of about 7 MΩ that for electrode 2 was also linear and, in some cases at short distances, had a slope as large as that for 1, i.e., the degree of electrotonic interaction was nearly 100%. However, in other impalements at short distances, interaction was nearly zero. Therefore, the degree of electrotonic spread was not dependent upon interelectrode distance per se, but appeared to depend on whether both electrodes impaled the same cell.
Carbohydrate content during development of the slime mold, Dictyostelium discoideum
Authors: Ceccarini C. , Filosa M.
Published: February 2005

Water soluble carbohydrates were studied at various developmental stages in the cellular slime mold, Dictyostelium discoideum. The only water soluble sugars found were, the non‐reducing disaccharide, trehalose and glucose. The level of trehalose varied very dramatically during the life cycle. Throughout the vegetative and migration stages the level of trehalose was less than 0.5% of the dry weight, but it quickly rose during culmination. During the later part of culmination trehalose reached a 1.5% level. In mature spores trehalose makes up more than 5% of the dry weight. The glucose level fluctuated very little during development. It reaches its highest level during the later part of culmination. In addition water insoluble sugars were extracted with 2.2% HCl. Their level remained constant throughout development and only increased in the complete fruiting body. The anthrone method was used for both water soluble and water insoluble carbohydrates. Trehalose was identified by IR spectroscopy.
Combined effects of chronic audio‐visual stress and thiouracil administration on the cholesterol‐fed rat
Authors: Anderson Thomas A. , Geber William F.
Published: February 2005

Weanling Sprague‐Dawley rats fed a standard laboratory diet containing 2% cholesterol and 1% sodium cholate, when exposed to audio‐visual stress for a three‐week period, were found to have significantly heavier thyroids, lighter livers, higher serum cholesterol and increased adrenal ascorbic acid levels than similarly treated control animals. The addition of thiouracil to the ration (0.25% and 0.50%) produced the expected increases in liver and thyroid weight and serum cholesterol. Thiouracil administration also caused a marked depression in adrenal weight and adrenal ascorbic acid levels. A significant stress X diet interaction was noted on thyroid weight, suggesting that stress and diet were not independent of each other in their influence on the thyroid. The combined effects of chronic audio‐visual stress and thiouracil administration had essentially no effect on total hepatic or adrenal cholesterol levels.
Studies on synchronously dividing cultures of Euglena gracilis Klebs (strain Z). II. Patterns of biosynthesis during the cell cycle
Authors: Edmunds Leland N.
Published: February 2005

Dry weight, total protein, chlorophyll a, carotenoids, soluble protein, RNA, DNA, and total phosphorus were determined at intervals of two hours during synchronous growth of Euglena at a cell concentration of 5–10 × 104 cells/ml maintained by periodic dilution. Detailed analyses of the soluble proteins (DEAE‐cellulose fractionation) and of the intracellular distribution of phosphorus were made also. In general, a linear doubling of each of these major components occurred during the light period; there was no net synthesis during the dark. Since cell number doubled during the dark period, a halving of the amounts of the parameters in each cell occurred. The most notable exception was the stepwise synthesis of DNA during the light period: DNA replicated during the last 6 hr only of the light period, commencing at 8 hr after the onset of light. Although DNA replication was a necessary condition for cell division to occur, it was not necessarily a sufficient one. It was found that different absolute rates of synthesis exist for the different compounds, with a doubling of a given parameter sometimes being completed before the end of the light period.
The initiation of cell division in a contact‐inhibited mammalian cell line
Authors: Todaro George J. , Lazar Gerald K. , Green Howard
Published: February 2005

The cells of an established mouse fibroblast line, 3T3, have a high plating efficiency and grow rapidly in sparse culture, but stop growing at a very low saturation density in comparison with other lines, because 3T3 is extremely sensitive to contact inhibition of cell division. After each medium change, however, there occurs in a small fraction of the cells in a saturation density culture a series of changes that results in a single rather synchronized division 30 hours later. This is due to a macromolecular substance in the serum which appears to act by reducing the sensitivity of the cells to contact inhibition. The first recognizable event following the addition of serum to a stationary phase culture is a ten fold increase in the rate of RNA synthesis, occurring within 30 minutes. An increase in the rate of protein synthesis follows several hours later. DNA synthesis does not begin before 12 hours, but by two hours after medium change an appreciable fraction of the cells become committed to eventual DNA synthesis and cell division. The sequence of event suggests that regulation of RNA synthesis is the means by which contact inhibition controls cell division.
A multisample chamber for dehydration and critical point drying
Authors: Gollin Susanne M. , Wray Wayne
Published: February 2005

The principles and methods for constructing an improved chamber for dehydration and critical point drying of multiple biological samples are described. The specimen chamber design is based on vertical positioning of the electron microscope grids or coverslips and permits minimal perturbation of laminar solvent flow past the specimens. This condition is requisite for optimal exposure of samples to solvents, which is necessary for complete dehydration and drying. Fragile samples, including chromosomes, critical point dried in the multisample chamber demonstrate crisp, well‐preserved, three‐dimensional morphology.
Effects of different epoxies on avoiding wrinkles in thin sections of botanical specimens
Authors: Pihakaski Kaarina , Suoranta Ulla‐Maija
Published: February 2005

Fold or wrinkles appear frequently in thin sections cut from botanical material embedded in epoxy resin such as Epon 812 (Polysciences) or EM‐bed‐812 (Electron Microscopy Sciences). Small wrinkles may occur more or less perpendicular to the cutting direction and mostly across the cell wall, causing problems in the examination of the ultrastructure. We studied the occurrence of wrinkles and folds by methodological sectioning, with regard to block hardness, use of Formvar‐support film, and chloroform vapor. Methodological sectioning or changing the block hardness did not reduce the occurrence of wrinkles in sections. Chloroform vapor improved the result as did also the use of uncoated grid. Wrinkles and folds could be avoided completely by embedding the specimens in LX‐112 (Ladd) or ERL‐4206 (Polysciences) low‐viscosity epoxy resins, in which case Formvar‐coated grids could be used, and chloroform vapor was not necessary.
Ultrathin formvar support films for transmission electron microscopy
Authors: Davison Edwin , Colquhoun William
Published: February 2005

We have found that ultrathin Formvar films are easily and reliably made at an air‐water interface by the drop method. By varying the concentration of Formvar in the drop, films of different characteristics can be obtained. Concentrations of 0.25–0.4% in ethylene dichloride produce extremely flat, ultrathin, and stable films that are especially suited for shadowed and negatively stained preparations. Low concentrations (⩽ 0.1%) produce nets consisting of many tiny holes which, after carbon stabilization, are ideal for supporting high‐resolution samples. Above 0.5%, films made by the drop method develop bubbles, and this bubble defect makes them unsuitable for section support.

For section support, Formvar films made by the stripping method off mica are far superior to those made off glass. The films are more uniform in surface contour and thickness. They are less readily attacked by alcohols. Consequently, they are more resistant to staining procedures involving organic solvents and continue to be strong and uniform for section support.
A comparison of specimen stage surface temperature and the GA‐1 control unit reading in Balzer's Freeze fracture microtome cold stage
Authors: Ruben George C.
Published: February 2005

The cold stage specimen surface in our Balzer's 300 Freeze‐etch instrument, averages 29–43°C warmer than the reading on the GA‐1 stage temperature control unit. By introduction of Indium foil seals above and below the stainless steel plug in the stage tower, the specimen cold stage surface temperatures were still 9–10°C warmer than the GA‐1 reading. After replacing the stainless steel plug with a copper plug and using Indium seals, the cold stage specimen surface was brought within 2.6°C of the GA‐1 temperature reading. In addition, the copper plug, Indium seal modified stage cools about two times faster in going from –100°C to –150°C than the normal stainless steel stage modified with Indium seals.
Ultra‐High‐Resolution electron‐beam lithography
Authors: Craighead H. G.
Published: February 2005

A conventional TEM/STEM has been used for the fabrication of ∼ 10 nm–size structures by electron‐beam lithography. The electron microscope provides a versatile tool for studying the lithographic process with control of the beam energy, current, and profile combined with the ability to image both the probe and fabricated structures. Straightforward techniques are described for generating ultrasmall structures for physics and device experiments on both bulk substrates and on thin films. New resist processes and the effects of electron‐beam energy as studied by these techniques are discussed.
Position stabilization of EELS spectra
Authors: Kruit Pieter , Shuman Henry
Published: February 2005

The position of the zero‐loss peak in electron energy‐loss spectra was sensed with a double photo diode. A signal, proportional to the disturbances from a central position, was amplified and fed back into a deflection coil in order to compensate for the origin of the disturbances. Thus, slow variations of the position of characteristic edges in the EEL spectrum could be reduced by a factor 100, and 60 Hz oscillations could be reduced by a factor 5.
Polyethylene glycol (PEG) embedding and subsequent de‐embedding as a method for the correlation of light microscopy, scanning electron microscopy, and transmission electron microscopy
Authors: Kondo Hisatake , Ushiki Tatsuo
Published: February 2005

The polyethylene glycol (PEG) embedding and subsequent deembedding method was applied to the observation of general tissues in scanning electron microscopy (SEM). Resulting SEM images were of high quality. It was demonstrated that intermicroscopic correlation of images between light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) is easily and reliably done by means of the PEG method. In particular, the exact correlation of immuno‐LM with SEM is shown to be of potential value.
A controlled atmosphere specimen holder for transmission electron microscopy
Authors: Chan Ignatius Y.
Published: February 2005

A controlled atmosphere specimen holder (CASH) has been developed for transmission electron microscopy (TEM) experiments. It is designed for studying the specimen's microstructure before and after treatments in various gases (H2, O2, N2, Ar, etc.) at temperatures up to 600°C. The experiments are carried out without exposing the specimen to the ambient atmosphere. No modification of the electron microscope itself is needed. The same area of the specimen can be easily located after each gas treatment, thus the changes in the microstructure can be studied directly. Preliminary results on the cyclic oxidation and reduction of a model cobalt catalyst are presented.
Cross‐sectional reflection electron microscopy of III–V compound epilayers
Authors: De Cooman B. C. , Kuesters K.‐H. , Carter C. B.
Published: February 2005

Reflection electron microscopy (REM) is shown to be applicable to the testing of the quality of AlxGa1−xAs/GaAs layer structures. Cross‐sectional images of quantum well structures with layer thickness down to 1 nm can be obtained. The practical aspects of the REM technique are presented. The most important advantages and drawbacks of cross‐sectional REM are discussed in detail.
Localization of membrane‐bound and soluble antigens using peroxidase‐labeled antibodies and preembedding immunoelectron microscopy
Authors: Osamura R. Y. , Watanabe K.
Published: February 2005

The immunoelectron microscopy preembedding method using peroxidase‐labeled antibodies has enabled us to localize various bioactive substances in subcellular organelles, i.e., nucleus, cytosol, perinuclear space, rough endoplasmic reticulum, Golgi complex, secretory granules, mitochondria, etc. In this text, detailed procedures and some key points for the appropriate staining are described. The applications of this technique to localize substances in various organelles and to observe ultrastructural changes of intracellular hormones are also discussed.
On the counting of electrons in high voltage electron microscopy
Authors: Pinna H. , Sirvin R. , Kihn Y. , Sevely J. , Jouffrey B.
Published: February 2005

This paper describes work on the counting of electrons in high voltage electron microscopy (HVEM). A reliable counting method is needed in order to perform quantitative experiments. A scintillator‐photomultiplier device has been adapted to these needs. It has been used here, in the field of electron energy loss spectroscopy. It permits the recording of the totality of the spectrum from the no‐loss peak to the inner shell excitation characteristic signals because of a dynamic equal to at least 7. A simple mounting has been made to eliminate the artifacts caused by X‐ray pulses. It is shown that HVEM is favourable to the counting of electrons, and some applications are reported.
Toward an understanding of liposome structure through the use of computer graphic image correlation
Authors: Zasadzinski Joseph A. N. , Kerins John , Davis H. T. , Scriven L. E.
Published: February 2005

A computer‐aided graphics approach to correlating transmission electron microscope images of freeze‐fractured and thin‐sectioned samples is outlined. Any three‐dimensional model of the imaged structure can be mathematically sectioned to provide a two‐dimensional representation of the model in the “fracture” plane. The method is used to demonstrate that the structure of lamellar liquid crystalline liposomes is based on a family of Dupin cyclides; closed, parallel surfaces with a conjugate ellipse and hyperbola as curvature defects.
Cytochemical identification of cerebral glycogen and glucose‐6‐phosphatase activity under normal and experimental conditions: I. Neurons and glia
Authors: Cataldo Anne M. , Broadwell Richard D.
Published: February 2005

Reliable ultrastructural techniques are applied for cytochemical identification of glycogen and localization of glucose‐6‐phosphatase (G6Pase) activity within neurons and glia of the adult mammalian CNS. Modulations in the cerebral localizations of glycogen and G6Pase activity are identified during various experimental conditions (i.e., salt‐stress, fasting, and trauma). The cytochemical reaction for demonstration of G6Pase activity implies that the enzyme acts as a phosphohydrolase to convert glucose‐6‐phosphate to glucose. The degradation of glycogen in vivo is one source of glucose‐6‐phosphate as a substrate for G6Pase. Glycogen is preserved by perfusion‐fixation of the brain with 2% glutaraldehyde‐2% formaldehyde. Chopper sections of this material are postfixed in buffered 1% osmium tetroxide‐1.5% potassium ferrocyanide, which serves as a contrast stain for glycogen, or in buffered 1% osmium tetroxide. Plastic‐embedded ultrathin sections of CNS tissue postfixed in 1% osmium tetroxide are stained for glycogen with periodic acid–thiocarbohydrazide‐silver protein. Intracellular glycogen appears as electron‐dense isodiametric particles and, under normal and experimental conditions, is most abundant within astrocytes. Neuronal glycogen is sparse to negligible normally but appears increased within specific neuronal populations during stressful states.

Optimal preservation of G6Pase activity in the brain is obtained by brief perfusion‐fixation with 2% glutaraldehyde. Tissue sections are incubated in a modified Leskes medium containing glucose‐6‐phosphate or mannose‐6‐phosphate as substrate and lead nitrate. Utilizing the Gomori lead capture technique, G6Pase reaction product is localized within the lumen of the endoplasmic reticulum (ER) and related organelles (i.e., nuclear envelope, Golgi complex) of perikarya, dendrites, and glia. The ER in axons and axon terminals fails to express G6Pase activity under normal conditions but does so in some neurons exhibiting a degenerating appearance. A transient, cytochemical decrease in G6Pase activity may occur within some perikarya during stressed conditions.

The results indicate that within neurons and glia of the adult CNS cytochemical stains are well suited for ultrastructural identification of glycogen and localization of G6Pase activity. Modulations in glycogen particle concentration and in localization of G6Pase activity in the neuron can occur in response to conditions that influence the energy metabolism of the cell. These modulations may reflect differences in the regional utilization of glucose as an energy‐producing substrate and as a derivative of glycogenolysis within the CNS.
Diffraction effect of x‐rays on the accuracy of quantitative analysis of crystals
Authors: Tanji Takayoshi , Yada Keiji , Kawamata Yasuhiro
Published: February 2005

In order to understand an apparent discrepancy of concentration of constituent elements in the quantitative analysis of thin KCl crystals with an energy dispersive X‐ray analyzer, which has been partly explained by fluorescent X‐ray excitation, more detailed experiments were carried out on binary alkali halides and tricomponent amorphous material by changing the azimuthal angle. Intensity ratios of X‐rays from the constituent elements in KCl and KBr single crystals varied considerably according to the rotation of the specimens. The observed differences between maximum and minimum intensity ratios were 15% for a thin KCl crystal about 100 nm thick and 20% for a bulk KCl crystal, which corresponded to 4.1% and 4.5% differences in atomic concentration, respectively. It was ascertained that for amorphous materials such as Co87Zr5Nb8, such a variation of the intensity ratio of X‐rays was not observed. It is thus proved that the variations of the intensity ratios of X‐rays from the constituent elements with azimuthal angle for KCl and KBr are attributed to the diffraction effect of characteristic X‐rays generated in crystalline specimens. This effect, which is the same as that in the production of Kossel patterns, is one of the essential factors limiting the accuracy of the analysis.
A staining syringe for multiple em grids
Authors: Järvilehto Matti , Harjula Riitta
Published: February 2005

In the EM‐routine, the thin sections are usually attached onto round copper grids. The sections on these EM‐grids are then stained either with a quite expensive automatic staining apparatus or by transporting the grids by hand from solution to solution. Here we will present a simple, inexpensive and truly reliable apparatus for staining and handling grids.
Comparison of polyethylene glycol and diethylene glycol distearate embedding methods for the preservation of fungal cytoskeletons
Authors: McKerracher Lisa J. , Heath I. Brent
Published: February 2005

Hyphae of the fungus Basidiobolus magnus were embedded in extractable polyethylene glycol (PEG) or diethylene glycol distearate (DGD) to prepare embedment‐free sections in order to seek components of the cytoskeleton that may be obscured in epoxy‐embedded sections. All methods showed that hyphae possess an intricate filamentous matrix, which is apparently unoriented. However, the appearance of the cytoskeleton depended on the embedding medium, the solvent used during embedding, and whether cells were fixed by conventional fixation or freeze‐substitution. PEG proved to be the best embedding medium for fungal cells because DGD caused cell shrinkage and produced a more lamellar than filamentous matrix. Also, the cytoskeletal filaments were clearer in freeze‐substituted cells than in conventionally‐fixed cells. Since we failed to find microtubules in the embedment‐free sections, we re‐embedded cells in Epon to discern whether microtubules or other cytoplasmic components had changed. Neither PEG nor DGD adequately preserved microtubules as compared to regular Epon‐embedded sections, and other cellular structures were significantly altered. Therefore, alternative methods need to be employed to further characterize fungal cytoskeletons.
Postembedding ultrastructural immunocytochemistry of neural antigens on tissues previously processed for routine light and electron microscopy: Preservation of antigenicity up to 22 years after initial fixation
Authors: Ross Amy A.
Published: February 2005

A postembedding immunocytochemical technique is described that allows ultrastructural localization of glial fibrillary acidic protein and neuron‐specific enolase on tissues originally processed only for routine light and electron microscopy. Use of the oxidizing agent sodium metaperiodate prior to incubation with the primary antiserum sufficiently removes osmium tetroxide (OsO4) from potential antigen—antibody combining sites to allow specific localization of these neural antigens by colloidal gold immunolabelling. Both human and monkey neural tissues, prepared for routine ultrastructural examination with aldehyde fixatives and OsO4 postfixation, show excellent ultrastructural morphology and antigen localization. In addition, formalin‐fixed, paraffin‐embedded pathological human brain tissues, obtained at autopsy up to 22 years previously, show good ultrastructural immunolocalization of glial fibrillary acidic protein when re‐embedded for electron microscopy. Thus, ultrastructural immunolocalization of certain neural antigens is easily achieved in tissues originally processed for routine light and electron microscopy. This allows re‐examination of archival tissues using current immunocy‐tochemical advances, including that of selected pathological tissues previously prepared solely for light microscopy.
A vacuum system for the production of clean carbon films
Authors: Lamvik M. K. , Voreades D. , Norton P. , LeFurgey A. , Ingram P.
Published: February 2005

A compact, oil‐free vacuum system has been assembled for the production of thin carbon films. Carbon rods are held in a simply constructed and easily cleaned rod holder. Using an unlubricated mechanical roughing pump and one sorption pump, the system is evacuated to the low millitorr range while completely avoiding oil vapors and contaminants that might derive from pump oil. Films produced in such systems are hydrophilic, and analytical electron microscopy measurements have shown that these films are adequately smooth and free of contaminants of both high and low atomic number.
An improved photographic process for convergent beam electron diffraction applications
Authors: Turner John H. , Krishnan Kannan M.
Published: February 2005

The use of a surface developer, pyrocatechol, to process transmission electron microscope negatives has been shown to have significant advantages over the conventional D‐19 process. The process described here is tolerant of a large margin of error in the electron exposure and produces a negative that not only retains details both in the highlight as well as the faint regions, but also preserves local contrast. These characteristics are particularly useful in convergent beam electron diffraction applications where one encounters a wide contrast range. Improved acuteness and an enhanced signal to noise ratio due to the prolonged exposures associated with this process have also been observed.
Preparation of holey carbon films suitable for cryo‐electron microscopy
Authors: Murray John M. , Ward Rob
Published: February 2005

We present a method for the quick and reliable production of carbon films perforated with 5–10‐μm holes, suitable for supporting suspensions that are to be rapidly frozen and imaged, using cryo‐electron microscopy, in the frozen‐hydrated state. The holes support biological specimens that are often embedded in 50–200 nm of vitreous ice, which is optimal for image contrast and preservation of large macromolecular complexes.
Use of backscattered electron imaging on developed radioautographic emulsions: Application to viewing rat incisor enamel maturation pattern following 45calcium injection
Authors: McKee M. D. , Warshawsky H. , Nanci A.
Published: February 2005

Backscattered electron imaging (BEI) can be used to obtain compositional contrast in biological structures because it detects differences in concentration of elements with different atomic number. Rat incisor enamel shows a banded pattern in the maturation zone when radioautography is used to reveal the location of injected 45Ca at the enamel surface. The bands of developed silver grains in the photographic emulsion that coats the enamel surface are ideal for atomic number contrast. The purpose of this study was to use BEI to analyze the radioautographic pattern with SEM resolution. One‐month‐old rats were injected with 45Ca and sacrificed at early (1 min, 5 min, 30 min), intermediate (4 h, 8 h), and late (1 day, 4 days) time intervals after injection. Whole incisors were dissected, the enamel organs were removed, and the enamel surface was coated with photographic emulsion and processed for radioautography. These radioautographed teeth were examined with a JEOL JSM‐840 SEM equipped with a JEOL backscatter annular‐type detector. At the early time intervals, light microscopic examination showed five or six broad black bands running obliquely across the teeth. These were separated by narrow white bands of unlabeled enamel. BEI resolved the presence of a delicate subbanding pattern within each dark band. At the intermediate time intervals, although the incisal bands persisted, only a diffusely blackened apical area was seen by light microscopy. BEI resolved bands in this apical region, but these showed no subbanding pattern. At the late time intervals, both light microscopy and BEI showed no banding, and the enamel was uniformly labeled. The significantly improved resolution obtained with BEI on surface radioautographs has revealed a previously undetected substructure in the 45Ca‐labeled banding pattern seen in enamel maturation.
Three‐dimensional analysis of high voltage electron microscope tilt images: Methods and problems
Authors: Hama Kiyoshi , Arii Tatsuo
Published: February 2005

A quantification program for obtaining three‐dimensional image information from high voltage electron microscope stereo pair pictures was developed for a Luzex 5000 image analyzer. A zero tilt image was used as a reference. A real‐time image processor system was introduced to improve the image quality and to reduce the beam damage of the specimens. Some modifications of the optical system and the specimen stage were made to improve the accuracy and efficiency of stereoscopy. The accuracy of the measurement was considerably improved by these modifications. Some basic problems and limitations of the method are discussed.
Rapid Embedding in Lowicryl K4M for Immunoelectron Microscopic Studies
Authors: Simon Gerard T. , Thomas Jennifer A. , Chorneyko Kathy A. , Carlemalm Eric
Published: February 2005

A rapid method of embedding tissues in Lowicryl K4M was developed. The initiator was replaced with benzoin ethyl ether, and the temperature of polymerization under indirect ultraviolet light was increased from −35°C to −10°C. The complete polymerization occurred in 24 hours. Compared with the original method and two other rapid methods proposed by Altman et al. (J. Histochem. Cytochem. 32:1217–1223, 1984), the above mentioned rapid method gave more reproducible results, and the preservation of the tissues was better. The preservation of the antigenicity was excellent as tested with anti‐amylase on zymogen granules of the rat's exocrine pancreas and with anti‐zona pellucida on ova of the golden hamster. Comparison of the preservation of antigenicity by means of the new rapid method shows an increased specific labeling when using the rapid Lowicryl K4M method as compared to the original Lowicryl K4M and Epon. Background levels between the original and rapid Lowicryl K4M methods are not significantly different. However, the two Lowicryl K4M methods differ significantly when compared to Epon. The reliability of this rapid method makes it suitable for introduction not only for research but also as a routine diagnostic histochemical technique at the ultrastructural level.
A glow discharge unit to render electron microscope grids and other surfaces hydrophilic
Authors: Aebi Ueli , Pollard Thomas D.
Published: February 2005

We describe the design, construction, and operation of a simple glow discharge unit that can be used to make surfaces such as carbon‐coated electron microscopy grids and glass coverslips hydrophilic. The use of a vacuum leak detector (Tesla coil) in place of a conventional high‐voltage power supply and a small plastic desiccator for the vacuum chamber make the unit very inexpensive. Owing to the small volume of the chamber and the simplicity of the unit, the whole glow discharge process can be carried out in only 2 to 3 min, a time considerably shorter than that required for conventional vacuum evaporators. The hydrophilic surface improves adsorption of particles by several orders of magnitude in preparation for negative staining, freeze‐drying, and other procedures.
Application of two‐bath development processing to transmission electron films and plates
Authors: Morse Daniel F.
Published: February 2005

In particular areas of materials research transmission electron microscopy has traditionally been plagued by the seemingly inherent problems of excessive photographic contrast and high densities. This need not always be the case. This article will suggest that the use of a development process in which the developing agent and its accelerator are split into two baths can accomplish the desirable effects of compressing the contrast range of the negative and limiting excessive density without loss of recorded detail. The developer used in the study is a commercially available formula called Diafine. Two‐bath developers can be formulated by individuals. At the time of writing, Diafine was the only off‐the‐shelf split developer known to the author.
Quantitative ultrastructural approach to the study of the spatial relationships among cell organelles. I. Cytological organization of human exocrine epithelia
Authors: Diaz Giacomo , Cossu Margherita , Riva Alessandro
Published: February 2005

Currently available morphometric methods provide useful information on the three‐dimensional properties (such as volume, surface, etc.) of biological structures. These methods, however, do not reveal how the same structures are spatially organized within the cell. A sum of problems, which concern mainly the definition of shape and location of the sectioned structures, does not allow the three‐dimensional representation of the organelle arrangement from a quantitative analysis of sections. Following a different approach, this study considers the topographic relationship between ten distinct subcellular structures: nucleus, Golgi, ribosomes, mitochondria, lysosomes, lipid droplets, secretory granules, and apical, lateral, and basal plasmalemma. The analysis of associations from 2 × 2 tables calculated for each pair of structures and the pattern of multiple associations obtained by clustering methods provide a useful description of the spatial relationship among different cell compartments. The results of the investigation carried out in parallel on seven human exocrine glands (pancreas, parotid gland, submandibular gland, lacrimal gland, ceruminous gland, ampulla of the vas deferens, and seminal vesicle) allow an immediate evaluation of the method and a comparative analysis of the cytologic organization of secreting cells of human exocrine glands.
A microcomputer program for the generation of random grid squares in quantitative analysis
Authors: Webber James S.
Published: February 2005

Subjectivity in selecting random grid squares for routine quantitative analysis can be circumvented through a combination of finder grids and a computer program. The simple BASIC program described in this paper generates a list of random grid‐square numbers, which are sequentially analyzed. The concept was applied in the quantitation of asbestos and other microparticles in environmental samples. The use of finder grids and this program can also be useful in quality‐control programs and in cross‐referencing analyses, as well as in the study of biological specimens.
Cross‐sectional transmission electron microscopy of silicon LSI circuits and josephson junction devices
Authors: Du A. Y. , Chu Y. M.
Published: February 2005

Cross‐sectional transmission electron microscopy (XTEM) has been used to diagnose silicon LSI circuits and Josephson junction devices. For LSI circuits, some typical failure problems have been presented. For Nb‐Si‐Nb Josephson junction, microholes in the thin silicon layer have observed, and they are responsible for the short circuiting of these devices.
Theoretical research on electron optics
Authors: Ximen Jiye
Published: February 2005

This paper summarizes theoretical research on electron optics in the field of electron microscopy that has been carried out by the author and his colleagues over a long period of time. The main topics to be discussed include the rotationally symmetrical imaging system and its aberrations; the method of matrix algebraic calculation and its applications to electron optics; new developments in scanning electron beam systems, i.e., the combined elec‐tromagnetic focusing‐deflection system with superimposed fields; the electromagnetic multipole system and its aberrations; the ion optical system with a curvilinear axis and its aberrations; and the phase retrieval in Fourier electron microscopy. This review may help to promote a better understanding of the present state of, and trends in, Chinese electron optics research.
Estimation of the mean caliper: A new simple approach
Authors: Elmalek Michelle , Hammel Ilan
Published: February 2005

Morphometric measurements are commonly carried out on structures the shape of which approximates that of a sphere. We calculated some stereological data of eosinophil granules by using digitized planimetry, performed on transmission electronmicrographs. By using a new approach for mean caliper (D) estimation and extrapolating an approximate granule axial ratio, we were able to calculate the granule density size. We deduced from a numerical analysis for various sphere sizes distributions from which an underestimation of not more than 4% may be contributed to D in most cases, assuming that the diameter coefficient of variation is less than 35%. The methodology we propose for mean ellipsoid caliper estimation seems to be useful in cases in which the disector method is not suitable.