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PubMed2005

Thinning rate of the precorneal and prelens tear films.

PURPOSE: To apply interferometry as an in vivo measure of tear film thinning between blinks. METHODS: Wavelength-dependent interference was used to measure the tear film thinning rates in 20 normal contact lens wearers, and spectra were captured at a rate of 4.5 per second for 20 seconds. Four recordings of precorneal tear film (PCTF) thinning were made, followed by 1 hour of hydrogel lens wear and then four recordings of prelens tear film (PLTF) thinning. Subjects were asked to blink 1 second after the beginning of the recording and then hold their eyes open for an additional 19 seconds, followed by 2 minutes of rest between recordings. RESULTS: The average thinning rate of the PLTF was greater than that of the PCTF and average initial tear film thickness of the PLTF was less than that of the PCTF. For both these reasons, the "tear thinning time" (time to reach 0 thickness) was typically shorter for the PLTF than for the PCTF. Histograms of PCTF and PLTF thinning rates showed a narrow peak corresponding to slow thinning of approximately 1 microm/min, but also many examples of rapid thinning of approximately 10 microm/min, with greater variability. Both the initial thickness and thinning rate of the PLTF correlated with corresponding values for the PCTF, although many more rapidly changing values were associated with the PLTF. Plots of rapid thinning of PCTF and PLTF were both linear and were not accompanied by any significant increase in thickness of corneal epithelium or contact lens, respectively. CONCLUSIONS: Tear film thinning can be analyzed in terms of flow in three spatial directions: (1) outward (evaporation), (2) inward (into the epithelium or contact lens), and (3) parallel to the tear film surface. The results indicate that the second mechanism may be unimportant. Studies have shown a range of tear film evaporation rates from 0.24 to 1.45 microm/min, whereas, when the lipid layer is washed away from the tear film, the thinning rate, due to evaporation, would be approximately 7 microm/min. Thus, slow thinning rates may be due to tear film evaporation, whereas rapid rates (which are often greater than 7 microm/min) presumably include other mechanisms such as dewetting, Marangoni flow (i.e., surface tension gradients), and pressure-gradient flow.

Adult↗
PubMed2005

Forest thinning and soil respiration in a ponderosa pine plantation in the Sierra Nevada.

Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and chemical properties. Forest thinning changes soil temperature, soil water content, and root density and activity, and thus changes soil respiration. We measured soil respiration monthly and soil temperature and volumetric soil water continuously in a young ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws.) plantation in the Sierra Nevada Mountains in California from June 1998 to May 2000 (before a thinning that removed 30% of the biomass), and from May to December 2001 (after thinning). Thinning increased the spatial homogeneity of soil temperature and respiration. We conducted a multivariate analysis with two independent variables of soil temperature and water and a categorical variable representing the thinning event to simulate soil respiration and assess the effect of thinning. Thinning did not change the sensitivity of soil respiration to temperature or to water, but decreased total soil respiration by 13% at a given temperature and water content. This decrease in soil respiration was likely associated with the decrease in root density after thinning. With a model driven by continuous soil temperature and water time series, we estimated that total soil respiration was 948, 949 and 831 g C m(-2) year(-1) in the years 1999, 2000 and 2001, respectively. Although thinning reduced soil respiration at a given temperature and water content, because of natural climate variability and the thinning effect on soil temperature and water, actual cumulative soil respiration showed no clear trend following thinning. We conclude that the effect of forest thinning on soil respiration is the combined result of a decrease in root respiration, an increase in soil organic matter, and changes in soil temperature and water due to both thinning and interannual climate variability.

California↗
PubMed2006

Lactate: creatinine ratio in babies with thin meconium staining of amniotic fluid.

BACKGROUND: ACOG states meconium stained amniotic fluid (MSAF) as one of the historical indicators of perinatal asphyxia. Thick meconium along with other indicators is used to identify babies with severe intrapartum asphyxia. Lactate creatinine ratio (L:C ratio) of 0.64 or higher in first passed urine of babies suffering severe intrapartum asphyxia has been shown to predict Hypoxic Ischaemic Encephalopathy (HIE). Literature review shows that meconium is passed in distress and thin meconium results from mixing and dilution over time, which may be hours to days. Thin meconium may thus be used as an indicator of antepartum asphyxia. We tested L:C ratios in a group of babies born through thin and thick meconium, and for comparison, in a group of babies without meconium at birth. METHODS: 86 consecutive newborns, 36 to 42 weeks of gestation, with meconium staining of liquor, were recruited for the study. 52 voided urine within 6 hours of birth; of these 27 had thick meconium and 25 had thin meconium at birth. 42 others, who did not have meconium or any other signs of asphyxia at birth provided controls. Lactate and creatinine levels in urine were tested by standard enzymatic methods in the three groups. RESULTS: Lactate values are highest in the thin MSAF group followed by the thick MSAF and controls. Creatinine was lowest in the thin MSAF, followed by thick MSAF and controls. Normal babies had an average L:C ratio of 0.13 (+/- 0.09). L:C ratio was more among thin MSAF babies (4.3 +/- 11.94) than thick MSAF babies (0.35 +/- 0.35). Median L:C ratio was also higher in the thin MSAF group. Variation in the values of these parameters is observed to be high in the thin MSAF group as compared to other groups. L:C ratio was above the cutoff of 0.64 of Huang et al in 40% of those with thin meconium. 2 of these developed signs of HIE with convulsions (HIE Sarnat and Sarnat Stage II) during hospital stay. One had L:C Ratio of 93 and the other of 58.6. A smaller proportion (20%) of those with thick meconium had levels above the cutoff and 2 developed HIE and convulsions with L:C ratio of 1.25 and 1.1 respectively. CONCLUSION: In evolving a cutoff of L:C ratios that would be highly sensitive and specific (0.64), Huang et al studied it in a series of babies with severe intrapartum asphyxia. Our study shows that the specificity may not be as good if babies born through thin meconium are also included. L:C ratios are much higher in babies with thin meconium. It may be that meconium alone is not a good indicator of asphyxia and the risk of HIE. However, if the presence of meconium implies asphyxia then perhaps a higher cut-off than 0.64 is needed. L:C ratios should be tested in a larger sample that includes babies with thin meconium, before L:C ratios can be applied universally.

Amniotic Fluid↗
PubMed1983

Thin filaments are not of uniform length in rat skeletal muscle.

The variation in thin filament length was investigated in slow and fast muscle from adult and neonatal rats. Soleus (slow) muscle from adult, 3-, 7-, and 9-d-old rats, and extensor digitorum longus (EDL; fast) muscle from adult rats were serially cross-sectioned. The number of thin filaments per 0.06 microns2 (TF#) was counted for individual myofibrils followed from the H zone of one sarcomere, through the I-Z-I region, to the H zone of an adjacent sarcomere TF# was pooled by distance from the Z band or AI junction. In both adult muscles, thin filament length varied from 0.18 to 1.20 microns, with approximately 25% of the thin filaments less than 0.7 microns in length. In 7- and 9-d soleus, thin filament length ranged from 0.18 to 1.08 microns; except for the longest (0.18 to 1.20 microns) filaments, the distribution of thin filament lengths was similar to that in adult muscle. In 3-d soleus, thin filament length was more uniform, with less than 5% of the filaments shorter than 0.7 microns. In all neonatal muscles, there were approximately 15% fewer thin filaments per unit area as compared to adult muscles. We conclude: (a) In rat skeletal muscle, thin filaments are not of uniform length, ranging in length from 0.18 to 1.20 microns. (b) There may be two stages of thin filament assembly in neonatal muscle: between 3 and 7 d when short thin filaments may be preferentially or synthesized or inserted near the Z-band, and between 9 d and adult when thin filaments of all lengths may be synthesized or inserted into the myofibril.

Animals↗
PubMed1974

Optical diffraction analysis of petrographic thin sections.

Diffraction patterns that are highly reproducible, of useful quality, and consistent with the input generating them can be easily obtained with a microscope system. The input can be either a reduced photograph or a thin section. With two exceptions, the relationships between a thin section and its diffraction pattern produced by a petrographic microscope are the same as the relationships between a photographic input and its diffraction pattern produced by a conventional ODA system. The exceptions are that the diffraction patterns generated directly by the thin sections may be asymmetrical or, if the thin section is sufficiently heterogeneous, may be smeared. The microscope system is generally more useful than a conventional ODA system for the analysis of microfabric in thin sections. One can readily use the microscope system to analyze elements of widely varying spatial frequency simply by changing the objectives. The diffraction patterns can be magnified by changing to a higherpower ocular. In most cases the microscope-generated diffraction pattern transmits the useful spatial information in the thin section more completely than the conventionally produced diffraction pattern; the photographic inputs for the conventionally produced diffraction pattern emphasize lower-frequency spatial information. This property, combined with the microscope system's better response to twinning, makes the microscope more sensitive to commonly used microfabric elements. For the analysis of thin sections, a conventional ODA system is superior to the microscope system in only three cases. First, if one wants to analyze the entire thin section at one time, a conventional system must be used with a photographic input of the thin section. Second, if the thin section is extremely heterogeneous (crystallographically or mineralogically), the microscope-generated diffraction pattern may exhibit gross smearing even with the highestpower objectives available. Finally, the thin section may contain only elements of low spatial frequency that will not generate diffraction dots far enough radially from the central spot to be resolvable. More study will be needed to establish the precision of spatial frequency measurements from diffraction patterns generated directly by thin sections with the microscope system. Experiments with a variety of film types and sources of illumination will, in all likelihood, lead to a reduction in the exposure times used to record diffraction patterns with the microscope (9). A complete ODA system must have directional and frequency-filtering capabilities. In order to establish these capabilities for the microscope system, components will need to be designed and fabricated and the microscope body may have to be modified. The possibility of applying the microscope technique in reflected light on a real-time basis should be investigated. This would be a valuable tool in the quantitative analysis of microfracture initiation and propagation and the analysis of overall fabric changes during experimental deformation of rock both in situ and in the laboratory. The technique presented here can be used with a less expensive microscope, if it has a focusable Bertrand lens. Our experiments with relatively inexpensive microscopes indicated that the only major problem is alignment of the illuminating system (light-filter-condenser).

Fourier Analysis↗
PubMed2005

Thinning effects on production, root biomass and some soil properties in a young oriental beech stand in Artvin, Turkey.

In this study, three thinning treatments were applied on a 0.54 ha young oriental beech (Fagus orientalis Lipsky) stand (25-30 years old) in Karadag, Artvin in the fall of 1999. The treatments were: (1) no thinning, (2) light thinning, and (3) heavy thinning. Prior to thinning, the stand averaged 15000 trees ha(-1) and 40.0 m2 ha(-1) of basal area, with an average mean diameter of 5 cm. Thinning reduced stand basal areas to about 31.1 and 24.9 m2 ha(-1) for the light and heavy thinning treatments, respectively. After 3-years, diameter increment was the highest in heavily thinned stand and the lowest in unthinned stand. The increment in stand basal area was about 10, 18 and 27% in the unthinned, lightly thinned, and heavily thinned stands, respectively. Fine root biomass significantly decreased with thinning and thinning had no significant effects on soil pH and soil organic matter content.

Biomass↗
PubMed1983

Transition in the thin-filament arrangement in rat skeletal muscle.

The transition in thin-filament arrangement from tetragonal near the Z-band to trigonal in the A-band was investigated by computer-assisted analysis of thin-filament arrangement in serially cross-sectioned rat muscle. Extensor digitorum longus (EDL; fast) muscle from adult rats and adult, 9-day and 3-day neonatal soleus (slow) muscle were serially cross-sectioned from the H-zone of one sarcomere to the H-zone of an adjacent sarcomere. Thin-filament arrangement was analysed throughout the I-band, and particularly at three levels of the sarcomere: in the I-band, one section (0.06 microns) from the Z-band; six sections (0.36 microns) from the Z-band; in the A-band, two sections from the A-I junction (0.72 microns from the Z-band). Data for radical distributions and annular distributions were obtained by computer. In all muscles studies, thin-filament arrangement exhibited four-neighbour ordering throughout the I-band. Thin-filament arrangement exhibited three-neighbour ordering only in the A-band. The transition in thin-filament arrangement from four-neighbour to three-neighbour ordering occurred within 0.12 microns of the A-I junction in muscles fixed at rest length. In adult soleus that had been stretched 20% so that the A-I junction moved away from the N2-line, the transition in thin-filament arrangement occurred in the I-band within a region 0.4-0.5 microns from the Z-band. This region corresponds to the N2-line region of the I-band. Thus, the transition from four-neighbour to three-neighbour ordering occurs in the I-band independent of the thin filament-thick filament interaction. We conclude that some inherent feature of the I-band or thin filament-thin filament interaction imposes a four-neighbour ordering on thin filaments from the Z-band to the N2-line.

Animals↗
PubMed1989

Prolonged abnormalities of left ventricular diastolic wall thinning in the "stunned" myocardium in conscious dogs: time course and relation to systolic function.

Myocardial reperfusion after reversible ischemia is known to be associated with prolonged abnormalities of systolic contractile function (myocardial "stunning"). However, no information is available regarding the recovery of diastolic function in the stunned myocardium in the conscious state. Accordingly, 10 conscious dogs instrumented with pulsed Doppler thickening probes underwent a 15 min occlusion of the left anterior descending coronary artery followed by 7 days of reperfusion. Regional systolic function was assessed as net systolic thickening fraction. Left ventricular regional diastolic properties were estimated from two variables: the mean rate to half end-diastolic thinning and the late diastolic thinning fraction. Both indexes of diastolic function remained severely impaired after restoration of flow. In general, the recovery of the mean rate to half end-diastolic thinning and of the late diastolic thinning fraction paralleled the recovery of systolic thickening, but the impairment of the mean rate to half end-diastolic thinning was more marked than that of the late diastolic thinning fraction. At 4 h of reperfusion, the values for the mean rate to half end-diastolic thinning and the late diastolic thinning fraction (expressed as percent of baseline) were 57 +/- 5% (p less than 0.001 versus baseline) and 79 +/- 7% (p less than 0.05), respectively, whereas systolic thickening fraction averaged 52 +/- 10% (p less than 0.001). At 24 h, the mean rate to half end-diastolic thinning and the late diastolic thinning fraction were no longer significantly different from baseline, whereas systolic thickening fraction remained decreased at 82 +/- 4% (p less than 0.001) and returned to control values by 48 h. This study demonstrates the presence of profound, prolonged abnormalities of regional diastolic wall thinning after a brief episode of ischemia in the conscious state and expands the concept of myocardial stunning from the traditional notion of impaired systolic performance to that of a global derangement in mechanical function that involves both systolic and diastolic properties.

Animals↗
PubMed2005

Fluorescence spectroscopic studies to characterize the internal environment of tetraethyl-orthosilicate derived sol-gel bulk and thin films with aging.

Characterization of the internal environment of a sol-gel matrix is an important area of investigation in optical biosensors. In the present study, different sol-gel compositions were prepared by varying the water (H2O) to tetraethyl-orthosilicate (TEOS) ratio (R) from 1 to 16 and the changes in the internal environment of the sol-gel both in bulk and thin films as a function of aging (storage) were investigated using fluorescence spectroscopy. We focussed on the fluorescence characteristics , viz. emission and excited state lifetime of Hoechst 33258 (H258), a bisbenzimidazole derivative, which was used as fluorescence probe entrapped in the TEOS derived sol-gel bulk and thin films. These sols were prepared at a low pH (approximately 2.0) and the thin films were coated by dip coating technique at withdrawal speeds of 1 cm/min and 0.1cm/min. Usually, uniform thin films were obtained at a high speed (1 cm/min) and partially cracked film at a low speed (0.1 cm/min) as observed by fluorescence microscope. These observations did not change during aging. On the contrary, three months long observations on steady-state fluorescence emission measurements on H258 depicted a blue shift from 535 nm to 508 nm at R = 1 in the sol-gel bulk, whereas at higher ratios this was not prominent. At all ratios, dual emission bands were observed in thin films. This may be due to faster sol-gel to xerogel transition during aging depending on the ratio (R). Analysis of the excited state decay profiles of H258 revealed a double exponential fitting having a short (tau1) and a long (tau2) component in both fresh and during aging, in the sol-gel bulk and thin films, indicating heterogeneity in the internal environment. The value of tau1 increased from 0.4 ns to 1.2 ns whereas tau2 attained a value from 3.0 ns to 3.6 ns at R = 1 upon aging in the sol-gel bulk. The corresponding values of tau1 and tau2 in thin films were 0.3 ns and 3.5 ns, respectively. The values of these decay components in thin films did not alter much due to storage, but their relative contributions showed more systematic changes in the thin films. The observed changes could be correlated to rigidification in the bulk depending on the ratio (R). This process was very slow at R > or = 4. The heterogeneity in the internal environment of bulk and thin films upon aging appeared to be different as revealed from analysis of excited-state lifetime. Thus, the bisbenzimidazole derivative H258 appears to be very useful probe for characterizing the internal environment of both the sol-gel bulk and thin films.

Luminescent Measurements↗
PubMed1980

Calcium ion-regulated thin filaments from vascular smooth muscle.

Myosin and actin competition tests indicated the presence of both thin-filament and myosin-linked Ca2+-regulatory systems in pig aorta and turkey gizzard smooth-muscle actomyosin. A thin-filament preparation was obtained from pig aortas. The thin filaments had no significant ATPase activity [1.1 +/- 2.6 nmol/mg per min (mean +/- S.D.)], but they activated skeletal-muscle myosin ATPase up to 25-fold [500 nmol/mg of myosin per min (mean +/- S.D.)] in the presence of 10(-4) M free Ca2+. At 10(-8) M-Ca2+ the thin filaments activated myosin ATPase activity only one-third as much. Thin-filament activation of myosin ATPase activity increased markedly in the range 10(-6)-10(-5) M-Ca2+ and was half maximal at 2.7 x 10(-6) M (pCa2+ 5.6). The skeletal myosin-aorta-thin-filament mixture gave a biphasic ATPase-rate-versus-ATP-concentration curve at 10(-8) M-Ca2+ similar to the curve obtained with skeletal-muscle thin filaments. Thin filaments bound up to 9.5 mumol of Ca2+/g in the presence of MgATP2-. In the range 0.06-27 microM-Ca2+ binding was hyperbolic with an estimated binding constant of (0.56 +/- 0.07) x 10(6) M-1 (mean +/- S.D.) and maximum binding of 8.0 +/- 0.8 mumol/g (mean +/- S.D.). Significantly less Ca2+ bound in the absence of ATP. The thin filaments contained actin, tropomyosin and several other unidentified proteins. 6 M-Urea/polyacrylamide-gel electrophoresis at pH 8.3 showed proteins that behaved like troponin I and troponin C. This was confirmed by forming interspecific complexes between radioactive skeletal-muscle troponin I and troponin C and the aorta thin-filament proteins. The thin filaments contained at least 1.4 mumol of a troponin C-like protein/g and at least 1.1 mumol of a troponin I-like protein/g.

Actins↗
PubMed2006

Restoration thinning and influence of tree size and leaf area to sapwood area ratio on water relations of Pinus ponderosa.

Ponderosa pine (Pinus ponderosa Dougl. ex P. Laws) forest stand density has increased significantly over the last century (Covington et al. 1997). To understand the effect of increased intraspecific competition, tree size (height and diameter at breast height (DBH)) and leaf area to sapwood area ratio (A(L):A(S)) on water relations, we compared hydraulic conductance from soil to leaf (kl) and transpiration per unit leaf area (Q(L)) of ponderosa pine trees in an unthinned plot to trees in a thinned plot in the first and second years after thinning in a dense Arizona forest. We calculated kl and Q(L) based on whole- tree sap flux measured with heat dissipation sensors. Thinning increased tree predawn water potential within two weeks of treatment. Effects of thinning on kl and Q(L) depended on DBH, A(L):A(S) and drought severity. During severe drought in the first growing season after thinning, kl and Q(L) of trees with low A(L):A(S) (160-250 mm DBH; 9-11 m height) were lower in the thinned plot than the unthinned plot, suggesting a reduction in stomatal conductance (g(s)) or reduced sapwood specific conductivity (K(S)), or both, in response to thinning. In contrast kl and Q(L) were similar in the thinned plot and unthinned plot for trees with high A(L):A(S) (260-360 mm DBH; 13-16 m height). During non-drought periods, kl and Q(L) were greater in the thinned plot than in the unthinned plot for all but the largest trees. Contrary to previous studies of ponderosa pine, A(L):A(S) was positively correlated with tree height and DBH. Furthermore, kl and Q(L) showed a weak negative correlation with tree height and a strong negative correlation with A(S) and thus A(L):A(S) in both the thinned and unthinned plots, suggesting that trees with high A(L):A(S) had lower g(s). Our results highlight the important influence of stand competitive environment on tree-size-related variation in A(L):A(S) and the roles of A(L):A(S) and drought on whole-tree water relations in response to thinning.

Arizona↗
PubMed2000

Regulation of force and unloaded sliding speed in single thin filaments: effects of regulatory proteins and calcium.

1. Measurements of the unloaded sliding speed of and isometric force exerted on single thin filaments in in vitro motility assays were made to evaluate the role of regulatory proteins in the control of unloaded thin filament sliding speed and isometric force production. 2. Regulated actin filaments were reconstituted from rabbit F-actin, native bovine cardiac tropomyosin (nTm), and either native bovine cardiac troponin (nTn), troponin containing a TnC mutant, CBMII, in which the sole regulatory site in cardiac TnC (site II) is inactivated (CBMII-Tn), or troponin containing a point mutation in TnT (I79N, where isoleucine at position 79 is replaced with asparagine) associated with familial hypertrophic cardiomyopathy (FHC). 3. Addition of regulatory proteins to the thin filament increases both the unloaded sliding speed and the isometric force exerted by myosin heads on the thin filaments. 4. Variation of thin filament activation by varying [Ca2+] or the fraction of CBMII/TnC bound to the thin filament at pCa 5, had little effect on the unloaded filament sliding speed until the fraction of the thin filament containing calcium bound to TnC was less than 0.15. These results suggest that [Ca2+] primarily affects the number of attached and cycling crossbridges. 5. The presence of the FHC TnT mutant increased the thin filament sliding speed but reduced the isometric force that heavy meromyosin exerted on regulated thin filaments. These latter results, together with the increased sliding speed and isometric force seen in the presence of regulatory proteins, suggest that thin filament regulatory proteins exert significant allosteric effects on the interaction of crossbridges with the thin filament.

Actins↗
PubMed1996

Sliding thin slab, minimum intensity projection technique in the diagnosis of emphysema: histopathologic-CT correlation.

PURPOSE: To assess the accuracy of sliding thin slab, minimum intensity projection technique in the detection of emphysema. MATERIALS AND METHODS: In 29 patients without radiographic evidence of emphysema and who were undergoing lung resection, focal spiral computed tomography (CT) was performed in the lobe to be resected. Ten contiguous 1-mm-thick CT scans and sliding thin slab, minimum intensity projection images with slab thicknesses of 3-, 5-, and 8 mm were generated. From each image, the presence and extent of emphysema were recorded before histopathologic analysis was performed. To familiarize readers with the appearance of normal lung parenchyma on sliding thin slab, minimum intensity projection images, five asymptomatic volunteers underwent scanning with a similar protocol. RESULTS: Emphysema was present on both thin-section CT scans and sliding thin slab, minimum intensity projection images in 13 patients. In all cases, sliding thin slab, minimum intensity projection images improved conspicuity of small areas of hypoattenuation. When thin-section CT scans were negative (n = 16), sliding thin slab, minimum intensity projection images enabled identification of focal zones of hypoattenuation in four cases with histologic confirmation of emphysema. Sensitivity of thin-section CT (62%) and sliding thin slab, minimum intensity projection technique (81%) were significantly different (P < .01); specificity for both was 100%. Emphysema was easier to detect on 8-mm-thick slabs because of better suppression of vascular structures. CONCLUSION: The sliding thin slab, minimum intensity projection technique enabled improved detection of mild forms of emphysema.

Adult↗
PubMed1994

Thin glomerular basement membrane in diabetic patients with urinary abnormalities.

To clarify the clinical and pathological significance of thin glomerular basement membranes (Thin-GBM) appearing in evident diabetics, we examined the renal biopsies from 179 diabetes mellitus (DM) patients with urinary abnormalities in which the number of non insulin dependent diabetes mellitus cases was 140 cases while the remaining 39 cases had insulin dependent diabetes mellitus. In addition, 17 of these cases were found to have either segmental or diffuse Thin-GBM by electron microscopy. The clinical and morphological parameters between the diabetics with Thin-GBM (DM-Thin-GBM) and the diabetics without Thin-GBM (the controls) were significantly different regarding DM duration (DM-Thin-GBM vs control: 5.3 +/- 5.5 vs 9.8 +/- 6.5 years, p < 0.01), Ccr (67.0 +/- 25.5 ml/min vs 45.6 +/- 24.4 ml/min, p < 0.01), the incidence of hematuria (52.9% vs 24.5%, p < 0.05) and hypertension (13.3% vs 51.3%, p < 0.05). The severity of glomerular damage was mild in the DM-Thin-GBM group as compared to the control. The renal survival rate from the onset of urinary abnormalities was higher in the DM-Thin-GBM group than in the control (p < 0.01). In the case of DM-Thin-GBM, the grade of proteinuria correlated with the mean width of the thickened GBM (p < 0.01) and the spread of the thickened GBM which was more than 500 nm in width (p < 0.001). The severity of microscopic hematuria correlated with the spread of the Thin-GBM (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Basement Membrane↗
PubMed2000

Thin-layer technology: tempered enthusiasm.

With the introduction of new technologies we often see a pattern of development. As a useful technology moves into the public sector there is often an episode of wild enthusiasm and uncritical acceptance, followed by a time of progressive disillusionment. However, with time and experience, a proper place for the method becomes established. Thin-layer technology is certainly an improvement and solves many of our preanalytical problems; however, it introduces some difficulties of its own. The rounding up of cells in liquid fixation makes cells of high-grade lesions smaller than they would be on a conventional preparation. The abnormal cells are often separated. For both of these reasons they may be overlooked. Furthermore, benign glandular cells can take on an ominous appearance. These differences in conventional and thin-layer morphology are proving to be a fruitful area for publication. Thin-layer technology cannot be all things to all situations, and this is especially true in body fluid and fine-needle cytomorphology. In our experience, while occasionally helpful, the thin-layer technique should not be the primary method for diagnosis in nongynecologic specimens. Time and effort would be better spent on trying to educate select clinicians on how to obtain better samples than to totally convert to thin-layer methodologies. Regarding FNA, the patient is best served when the pathologist is directly involved with the initial sample acquisition. Reimbursement is available for immediate sample interpretation, so funding should be available for staffing if an institution has the interest. For the record, we believe that liquid fixation and thin-layer methodology should not be the primary method for FNA, unless circumstances are absolutely prohibitive. An important problem with thin-layer technology lies with its added cost. Thin-layer interposes another series of steps into cytologic sample preparation. There is additional labor, additional time, another machine in the laboratory, and the significant cost of the reagents. In a situation where the price of a cytologic test is already close to margin, costs of the vial, filter, and preservative throw the test into unprofitability. Price structures have to be changed. Some institutions are waiting until there is more competition in the market and costs decrease. Alternatively, a lot of effort has been expended in trying to get government and other groups to accept the additional costs of the new test for gynecologic examinations, and many payers seem to be falling in line to accept the methodology, secondary to clinician and patient demand. Basic questions about ancillary technologies and gynecologic samples remain to be answered. Cytology is big business. Every year a significant segment of the population has a Pap smear performed. Hardly any other laboratory test can claim the volume of activity of the cervical smear. Any business that can hook into that market stands to prosper. Since the Pap smear has some well-publicized problems, the door is open for technology to nibble away at a few percentage points of false negativity. We are far from the first to ask if we can afford the incremental improvements of thin-layer and other ancillary technologies. There is a conundrum. Government, insurance companies, and our administrators are calling for us to hold back cost increases in medical care. Alternatively, these new technologies, patient demand for the perfect test, increased regulatory oversight, and legal challenges are increasing the cost of doing business. We do not know how to respond to the often-voiced fear that these ancillary technologies increase the cost of cytology services beyond some patients' ability to pay. In this confusion, we do know that we should use the best test to get the most accurate answer for our patients. In selected scenarios this may mean that we will have to accept the cost and follow thin-layer technology.

Breast Neoplasms↗
PubMed1982

Histotopography and ultrastructure of the thin limbs of the loop of Henle in the hamster.

In the kidney of the Syrian hamster the descending thin limbs of both the short and long loops of Henle are not spatially separated from each other and descend between the vascular bundles. Ultrastructurally, five different epithelial types are distinguished in the thin limbs of the short and long loops of Henle. Short loops possess only a descending thin limb with a simply organized epithelium (type 1). Long loops comprise an upper and a lower part of the descending thin limb and the ascending thin limb. The upper part of the long descending thin limb is equipped with a complex and highly interdigitating epithelium with shallow junctions (type 2), which gradually transforms into the simple noninterdigitating type-3 epithelium of the lower part. In a minor portion of long descending thin limbs, however, the upper part begins with an even more complexly organized epithelium (type 2a) than type 2. Type-2a epithelium is conspicuously thicker and possesses a more elaborate mode of cellular interdigitation. Along the descent of this tubular part through the inner stripe of the outer medulla, type-2a epithelium transforms into type-2 epithelium. It is suggested that the long descending thin limbs, which start with type-2a epithelium, belong to the longest loops. The type-4 epithelium of the ascending thin limbs is characterized by flat and extensively interdigitating cells with shallow junctions. The unique pattern of the type-2a epithelium favors the assumption that solute secretion essentially contributes to the increase in concentration of tubular fluid in long descending thin limbs.

Animals↗
PubMed2005

Thin-section multiplanar reformats from multidetector-row CT data: utility for assessment of regional tumor extent in non-small cell lung cancer.

PURPOSE: To determine the clinical utility of thin-section multiplanar reformats (MPRs) from multidetector-row CT (MDCT) data sets for assessing the extent of regional tumors in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: Sixty consecutive NSCLC patients, who were considered candidates for surgical treatment, underwent contrast-enhanced MDCT examinations, surgical resection and pathological examinations. All MDCT examinations were performed with a 4-detector row computed tomography (CT). From each raw CT data set, 5mm section thickness CT images (routine CT), 1.25 mm section thickness CT images (thin-section CT) and 1.25 mm section thickness sagittal (thin-section sagittal MPR) and coronal images (thin-section coronal MPR) were reconstructed. A 4-point visual score was used to assess mediastinal, interlobar and chest wall invasions on each image set. For assessment of utility in routine clinical practice, mean reading times for each image set were compared by means of Fisher's protected least significant difference (PLSD) test. A receiver operator characteristic (ROC) analysis was performed to determine the diagnostic capability of each of the image data sets. Finally, sensitivity, specificity and accuracy of the reconstructed images were compared by McNemar test. RESULTS: Mean reading times for thin-section sagittal and coronal MPRs were significantly shorter than those for routine CT and thin-section CT (p<0.05). Areas under the curve (Azs) showing interlobar invasion on thin-section sagittal and coronal MPRs were significantly larger than that on routine CT (p=0.03), and the Az on thin-section sagittal MPR was also significantly larger than that on routine CT (p=0.02). Accuracy of chest wall invasion by thin-section sagittal MPR was significantly higher than that by routine CT (p=0.04). CONCLUSION: Thin-section multiplanar reformats from multidetector-row CT data sets are useful for assessing the extent of regional tumors in non-small cell lung cancer patients.

Adult↗
PubMed2005

Oxidized and acid thinned starch derivatives of hybrid maize: functional characteristics, wide-angle X-ray diffractometry and thermal properties.

Starch isolated from hybrid maize (8535-23) was subjected to oxidation and acid thinning. Proximate analyses revealed that moisture, ash, protein, fat, fibre, and pH reduced after oxidation and acid thinning. Percentage amylose content reduced from 20.42% in native starch to 18.76 and 17.65% in oxidised and acid thinned starch derivatives, respectively. Wide-angle X-ray diffraction patterns indicated strong peaks at 15.9 degrees, 17.2 degrees, 18.8 degrees, and 25.0 degrees 2theta. No significant difference was observed between the X-ray pattern of the native and modified starches. Both swelling power and solubility increased with increase in temperature. Oxidation and acid thinning reduced swelling power and increased solubility starch. At all pHs, both oxidation and acid thinning reduced the swelling capacity of the native starch. Oxidation increased water and oil absorption capacity of the native starch, while both hydrophilic and hydrophobic properties reduced following acid thinning. Least gelation concentration reduced in acid thinned starch but increased in oxidised derivative. Pasting temperature (Tp), peak viscosity (Pv), hot paste viscosity (Hv), and viscosity after 30 min holding at 95 degrees C (H(v30)) reduced following both modifications. However, values for cold paste viscosity (Cv) and setback (SB) reduced in oxidised derivative and increased in acid thinned starch. Light transmittance of the starch pastes reduced with increase in storage days, however, reduction was more pronounced in native and acid thinned starches. Onset temperature (To), peak temperature (Tp) and conclusion temperature (Tc) of gelatinisation reduced in modified starches compared with native hybrid maize starch. Also, gelatinisation enthalpy reduced after oxidation and acid thinning. Enthalpy of regelatinisation increased as days of storage of starch paste increased.

Acids↗