Effects of time and temperature during attachment of sections to microscope slides on immunohistochemical detection of antigens.

To study the effects of time and temperature on attachment of tissue sections to microscope slides, we examined the intensity of immunohistochemical staining of selected antigens in nine different neoplastic and normal tissues after attaching sections at different times and temperatures. Typically, both the temperature and time are minimized when tissue sections attached to slides; however, suboptimal times and temperatures during attachment may result in either loss of tissue due to poor attachment or the necessity for inconvenient staining regimens. Using standard immunohistochemical techniques, 5 microm tissue sections were attached at 58 degrees C for 1, 4 and 24 hr. In a separate study, 5 microm tissue sections were attached for 16 hr at 58, 68 and 80 degrees C. The intensity of staining decreased slightly when the tissue sections were heated at 80 degrees C for 16 hr, but there was little or no decrease when tissues were heated at 68 degrees C or lower for 16 hr, or at 58 degrees C for up to 24 hr.     

Measuring beyond the microscope field of view using digital images in squamous cell carcinoma of the lip

OBJECTIVE: To study the impact of using digital images for measuring the size of the tumors, assisting with the prognostic evaluation of carcinomas of the oral mucosa. STUDY DESIGN: The depth of invasion of 12 cases of squamous cell carcinoma of the lower lip was assessed through a microscope and through digital images. All measurements of depth of invasion were assessed in a direction orthogonal to the lip surface. First, assessment of depth of invasion was done at the microscope, using an eyepiece reticule with an engraved scale. Second, depth of invasion was assessed by digital images, using a program module developed to assist pathologists with linear measuring. When the depth of the tumor was larger than the field of view at the proper magnification, several images were taken to include the whole area of invasion. The images were finally mounted in a single image and the depth of invasion measured. RESULTS: The results show positive and negative differences between assessments when assessing depths of < 2 mm. At greater depths (> or = 2 mm), the difference was always negative, showing that for deep invasion, measurements of longer distances were always performed on digital images. CONCLUSION: Measurements with digital images beyond the field of view at proper magnification could sig nificantly alter the diagnostic and prognostic assessment made using the microscope.     

An electron microscope study of the influence of divalent ions on myosin filament formation in chicken gizzard extracts and homogenates

Myosin as well as actin filaments could be seen in negatively stained preparations of fresh chicken gizzard homogenized in buffered KCI (I=0-12, pH 6.85), in a 1 : 1 ratio. Myosin filaments were also present when homogenates were diluted (1 : 9) with solutions containing additional Mg(++) and ATP provided naturally occurring traces of Ca(++) had not been chelated with EGTA. There were no myosin filaments when Mg(++), ATP, Ca(++) or Ca(++) + ATP were added respectively to the diluent. It is suggested that in vivo in relaxed muscles myosin is present in dimers, and only aggregates into filaments at the onset of contraction when Ca(++) are released.     

The influence of age on tooth root colour changes

The purpose of this study was to examine the relationship between tooth root colour and age, and its possible application in age assessment. In this research altogether 100 tooth roots have been analysed. All teeth, that is their roots, were digitally recorded and the colorimetric treatment was made using Adobe Photoshop 7.0 computer program. Studies have shown no significant difference between RGB values analysed on the whole root surface or only on its central part, with certainty p >0.99. It is also established that there is no statistically significant difference in colouration on four anatomical surfaces (buccal, mesial, lingual, distal) of tooth roots with certaintyp>0.99 for red, p>0.99 for green and p>0.50 for blue colouration component. Statistical data interpretation showed that there is a linear correlation between obtained RGB values and age, with r=-0.994, p>0.99 for red component, r=-0.972, p>0.99 for green and r=-0.982, p>0.95 for blue colouration component. From the obtained results it is possible to conclude that analysing the above mentioned parameter we can easily establish dental age and this technique can be the basis of practical application in establishing chronological age of man.     

The influence of data shape acquisition process and geometric accuracy of the mandible for numerical simulation

Computer-aided technologies have allowed new 3D modelling capabilities and engineering analyses based on experimental and numerical simulation. It has enormous potential for product development, such as biomedical instrumentation and implants. However, due to the complex shapes of anatomical structures, the accuracy of these technologies plays an important key role for adequate and accurate finite element analysis (FEA).

The objective of this study was to determine the influence of the geometry variability between two digital models of a human model of the mandible. Two different shape acquisition techniques, CT scan and 3D laser scan, were assessed. A total of 130 points were controlled and the deviations between the measured points of the physical and 3D virtual models were assessed.

The results of the FEA study showed a relative difference of 20% for the maximum displacement and 10% for the maximum strain between the two geometries.     

The influence of data shape acquisition process and geometric accuracy of the mandible for numerical simulation

Computer-aided technologies have allowed new 3D modelling capabilities and engineering analyses based on experimental and numerical simulation. It has enormous potential for product development, such as biomedical instrumentation and implants. However, due to the complex shapes of anatomical structures, the accuracy of these technologies plays an important key role for adequate and accurate finite element analysis (FEA). The objective of this study was to determine the influence of the geometry variability between two digital models of a human model of the mandible. Two different shape acquisition techniques, CT scan and 3D laser scan, were assessed. A total of 130 points were controlled and the deviations between the measured points of the physical and 3D virtual models were assessed. The results of the FEA study showed a relative difference of 20% for the maximum displacement and 10% for the maximum strain between the two geometries.     

The digital processing of the images in x-ray microanalysis

Image analysis of X-ray microanalytical maps of sodium, potassium, phosphorus, chloride and calcium was carried out on the IBAS image analysis system (OPTON, FRG). In the present work, algorithms were developed for getting a new semiquantitative information from the binary images of maps: the element profile on the chosen line, the isoconcentration mapping and the multiple elemental mapping. It is possible to get as many as eight different elemental maps on the same image (with 8-bit resolution of pixel) and to extract the pixels with element overlappings.     

Impact of disease mutations on the desmin filament assembly process

It has been documented that mutations in the human desmin gene lead to a severe type of myofibrillar myopathy, termed more specifically desminopathy, which affects cardiac and skeletal as well as smooth muscle. We showed recently that 14 recombinant versions of these disease-causing desmin variants, all involving single amino acid substitutions in the alpha-helical rod domain, interfere with in vitro filament formation at distinct stages of the assembly process. We now provide mechanistic details of how these mutations affect the filament assembly process by employing analytical ultracentrifugation, time-lapse electron microscopy of negatively stained and glycerol-sprayed/low-angle rotary metal-shadowed samples, quantitative scanning transmission electron microscopy, and viscometric studies. In particular, the soluble assembly intermediates of two of the mutated proteins exhibit unusually high s-values, compatible with octamers and other higher-order complexes. Moreover, several of the six filament-forming mutant variants deviated considerably from wild-type desmin with respect to their filament diameters and mass-per-length values. In the heteropolymeric situation with wild-type desmin, four of the mutant variants caused a pronounced "hyper-assembly", when assayed by viscometry. This indicates that the various mutations may cause abortion of filament formation by the mutant protein at distinct stages, and that some of them interfere severely with the assembly of wild-type desmin. Taken together, our findings provide novel insights into the basic intermediate filament assembly mechanisms and offer clues as to how amino acid changes within the desmin rod domain may interfere with the normal structural organization of the muscle cytoskeleton, eventually leading to desminopathy.     

The influence of soil colour on subspeciation of mammals in eastern Arabia

Some subspecies of mammals described from the Batinah Coast of Oman are discussed. The coloration of certain terrestrial forms is considered to be correlated with predominant soil coloration in their habitats. The Baluchistan gerbil, Gerbillus nanus , exists in two quite distinct colour forms on each side of the Oman range, which we have shown to correspond closely with the coloration of soil samples obtained from the areas in which they were collected. A pale sandy form near to G.n. arabium lives on the pale sands fringing Rub al Khali, while a much darker form G.n. setonbrownei lives on the darker soil of the Batinah Coast.     

The influence of shape and colour cue classes on facial health perception

Facial appearance signals information about an individual, and one trait in particular is vitally important for social interaction and mate choice decisions: physical health. Facial cues to health can be divided into two broad classes - facial shape, which is linked to previous health and is relatively fixed; and facial colouration, which changes over the short-term, reflecting current health. These cue classes in themselves give insight into the kinds of health condition valued by human observers when making social inferences. Here, using novel and generalizable methods, the influence of these cue classes on health perception and their link to a measure of general health are examined. Study One employs a Brunswik lens model approach, finding that observers utilise exclusively shape cues to judge health, and that of these shape cues, only averageness is related to a measure of self-reported general health. Study Two shows that when averageness and carotenoid colouration are varied together, both make separable contributions to perceived health, but that averageness explains a larger proportion of variance. Taken together, these results indicate that humans may have evolved to favour cues to previous condition when judging health, because they are more valid. However, the findings also suggest that the role of facial appearance in perceiving health is more complex than previously thought, with different cues potentially reflecting specific aspects of physiological health.     

The influence of clothing ensembles on the lower critical temperature

This paper describes the effect of clothing insulation on the lower critical temperature (LCT). Twelve young adult females were exposed to a temperature of 10 degrees C for 2 1/2 h. LCT was estimated at five different clothing conditions according to the intersect method. The total weights of clothing ensembles (CW) of the five conditions were 0.45, 0.52, 0.82, 1.34, and 2.56 kg, and their thermal insulating values (I) were 0.44, 0.60, 0.77, 1.21, and 2.14 clo, respectively. LCT of the five clothing ensembles were estimated to be 26.4, 25.4, 23.5, 21.5, and 17.5 degrees C, respectively. The regression equation of the logarithm of LCT on CW was calculated as logLCT = 1.4469-0.08283 CW and that on I was log LCT = 1.4613-0.10526 I, respectively. The rate of changes in LCT is suggested to be dependent on the clothing conditions as for the following equations: dLCT/dCW = -5.34 exp(-0.1907 CW) or dLCT/dI = -7.01 exp(-0.2424 I).     

Automated image analysis of live/dead staining of the fungus Aureobasidium pullulans on microscope slides and leaf surfaces

An image analysis program and protocol for the identification and enumeration of live versus dead cells of the yeast-like fungus Aureobasidium pullulans was developed for both populations on microscope slides and leaf surfaces. Live cells took up CellTracker Blue, while nonviable cells stained with DEAD Red. Image analysis macro programs running under Optimas software were used to acquire images and to differentiate and enumerate viable from nonviable cells. The software was capable of discriminating green as a third parameter for identification and quantification of green fluorescent protein-expressing cells in a wild-type population.     

The influence of light environment on host colour preference in a parasitoid wasp

1. Visual chromatic cues and contrast effects are widely used by insects in behaviours involving host/prey/mate‐finding and recognition. However, naturally changing light conditions may challenge the visual perception of cues for these organisms. 2. We used the host/parasitoid system Acyrthosiphon pisum/Aphidius ervi to determine if apparent visual preference of the wasp for green over pink host aphids was a visually based choice or a post‐attack mechanism based on host susceptibility depending on anti‐parasitoid symbiotic bacteria. 3. The study tested the ability of the wasp to recognise and attack pea aphid clones expressing variation based on colour and/or symbionts under a broad range of LED‐controlled light environments mimicking natural variations. 4. Results showed that the amount of reflected light of pink morphs was about half that of the green morphs in the cyan‐green components. Both host colours were recognised and attacked under all tested light conditions, even red light (660 nm). The previously reported preference of A. ervi for green pea aphids, was clear only for naive females given a choice between two aphid colours under all light environments, but quickly disappeared. 5. Wasps showed no tendency of avoiding oviposition in clones with defensive symbionts. 6. These findings suggest that variable rates of pea aphid parasitism by A. ervi in fields do not depend on host colour discrimination, but rather on susceptibility variation among aphid clones in allowing larval development after egg‐laying. Further studies should consider deeper investigation of the impact of red lights used in modified light environments in greenhouses and the proportion of host colour morph available.     

The influence of ambient temperature on the abundance of Poaceae pollen

The sampling of pollen concentrations over six seasons in north London has revealed the importance of temperature in influencing the start, severity, daily and diurnal variation of Poaceae pollen seasons. Using accumulated degree days above 6°C and rainfall amount as predictors, models have been developed which account for 96% of the variation in the starting date and 91% of the variation in the severity of the Poaceae pollen season. Maximum daily temperature is an important influence on the daily pollen count although this relationship is not linear and maximum daily temperatures within the range 21.1–25°C are associated with the highest daily pollen concentrations. Likewise, when the two-hourly variation of pollen concentration is examined, temperatures within 2–4.9°C above the normal diurnal range, rather than in excess of 5.0°C, are found to be associated with the highest two-hourly concentrations. Occasional night-time maxima of pollen concentration have also been recorded and these are examined in relation to the possibility of temperature inversions, although few conclusive results have emerged.