Application of a multiwire proportional chamber to the detection of axoplasmic transport

The distribution of residues of DDT and its metabolites (DDD and DDE) in tissues of Triaenophorus nodulosus and its host was studied. It has been noted that cestodes can accumulate chlororganic substances in great quantity. The ability of Bothriocephalus gowkongensis has been established to dechlorate pp-DDT and to excrete pp-, op- and mp-DDD from the organism. Pp-DDT decreases the glycogene content and causes the rise of amylolytic activity in the above cestodes in acute tests. The effect of pp-DDT on the locomotor activity of cestodes is of two-phase character. The first one is associated with the muscular influence, the second one-- with neurotrophic effect. A high toxicity of mp-DDD )0.1 mg/l) for the locomotor activity of cestodes as compared with the effect of pp- and op-DDD was revealed.     

Quantitative autoradiography of halothane binding in rat brain

14C-halothane direct photoaffinity labeling was used to characterize the distribution of halothane binding in rat brain to test the hypothesis that anesthetics bind preferentially to a specific, heterogeneously distributed, receptor or channel. Slide-mounted sagittal rat brain sections were placed in gas-tight quartz cuvettes with 100 microM 14C-halothane in phosphate buffered saline with 0 to 7.5 mM unlabeled halothane, or unlabeled chloroform and isoflurane at 10 times the clinical EC50, and then exposed to UV light for 60 to 100 sec. Autoradiograms of nine brain regions (cortex, corpus callosum, hippocampal molecular and pyramidal layers, dentate molecular and granule cell layers, and cerebellar molecular, granular and white matter layers) were prepared and quantitated using Image 1.44. Total label incorporation was widespread, but exhibited subtle heterogeneity. There was significantly more total labeling in regions of high synaptic density than in regions containing primarily cell bodies or white matter. Most labeling (approximately 80%) was displaced by unlabeled halothane and can therefore be considered specific. Significantly more specific labeling was found in regions of high synaptic density. Isoflurane did not inhibit halothane photolabeling significantly, but chloroform inhibited it by approximately 50%. In conclusion, halothane photolabeling distribution in the mammalian brain is widespread, saturable and selective, but does not mimic the distribution of any individual receptor or channel. Brain regions with high synaptic density displayed the greatest degree of specific binding, consistent with transmission being an important functional target of volatile anesthetics. These results suggest a remarkably widespread individual target, or more likely, similar binding sites in multiple targets, and are consistent with the notion that anesthesia is the result of action at multiple sites.     

Microdosimetric analysis of radiation from a clinical mammography machine using realistic breast phantoms and a miniature proportional counter

We have measured the microdosimetric spectra of a Senographe 600T mammography machine employing an Mo target with 0.8 mm Be inherent filtration and 0.03 mm Mo added filtration, giving a half-value layer of 0.35 mm A1 at 28 kVp. In all of our measurements a large collimator producing a 24 cm x 30 cm field at 65 cm was used. Two different phantom compositions differing in the ratio of adipose to fibroglandular tissue were compared, using simulated breast material from Nuclear Associates. Spectra were taken at various depths and locations in simulated breasts of 3.4 and 5 cm thickness. The detector used was a miniature proportional counter having outer dimensions of 5 cm x 1.8 cm diameter, with a sensitive volume 0.5 mm x 0.5 mm. The small dimensions of the counter and the cavity allowed total embedding in the breast material with minimal disturbance of the photon and secondary electron spectrum. Our results show that there can be changes in the radiation quality amounting to as much as 17% (as measured by the dose mean lineal energy. yD) between breasts of different thickness, at the same relative position within the breast. There is little difference due to breast composition.     

Studies on the quantitative autoradiography. I. Radioluminography for quantitative autoradiography of 14C

Highly variable microsatellites enabled a precise assessment of the number of queen matings in the colonies of five bumble bee species. Fifteen of the sixteen microsatellites initially cloned from B. terrestris had flanking regions similar enough to allow PCR amplification on the other Bombus species analysed. The microsatellites selected for intracolony study (four per species) were characterized by a high heterozygosity (0.58-0.93) and a large number of alleles (3-18) in the local populations from which the colonies originated. A single male appeared to have inseminated the queens in the colonies of four species, B. terrestris, B. lucorum, B. lapidarius and B. pratorum, which belong to three subgenera, whereas two of the three analysed colonies of B. hypnorum were polyandrous (minimum number of two and four patrilines, respectively).     

基于破碎性能和衬板磨损特性分析的旋回破碎腔型优化设计

在分析当前旋回破碎腔型结构及衬板磨损特征的基础上,通过计算破碎腔各截面通过率确定破碎产能,采用三次样条曲线对破碎腔型进行几何描述.以破碎生产率和啮角为约束条件建立破碎腔的目标函数,对旋回破碎腔进行优化设计,利用计算机绘制腔型曲线.按照高铝矿的破碎实际要求制定了实验方案.实验结果表明,采用优化后腔型和新衬板,其破碎产能、破碎产品的合格率和衬板耐磨寿命均有显著提高.     

Quantitative analysis of Epstein-Barr virus load by using a real-time PCR assay

BACKGROUND: Previous studies have suggested a variety of factors that may be associated with the presence of hippocampal formation (HF) atrophy in patients with complex partial seizures (CPS), including a history of complex or prolonged febrile seizures (FS), age at seizure onset, and epilepsy duration. OBJECTIVE: To determine whether epilepsy duration is related to HF atrophy. Methods: We performed MRIs on 35 patients with uncontrolled CPS who had temporal lobe ictal onset on video-EEG. None had evidence for an alien tissue lesion or extra-hippocampal seizure onset. All had a history of secondary generalization. Brain structures were drawn on consecutive images and pixel points summed from successive pictures to calculate volumes. RESULTS: Nine patients with a history of complex or prolonged FS had smaller ipsilateral HF volume and ipsilateral/contralateral ratio than did patients without a history of FS. Epilepsy duration had a significant relation to ipsilateral HF volume and ipsilateral/contralateral ratio. In a multivariate analysis, the effect of duration, but not age at onset or scan, was significant. Patients with a history of FS did not have earlier age at epilepsy onset or longer duration. Conclusions: A history of FS predicted the severity of HF atrophy in our patients. Age at onset or study was not a significant factor. Epilepsy duration, however, did have a significant effect, suggesting that, after an initial insult, progressive HF damage may occur in patients with persistent seizures.     

Effect of temporal position, proportional variance, and proportional duration on decision weights in temporal pattern discrimination

Two experiments investigated how listeners allocate their attention to different segments of a temporal pattern. The experiments allowed a direct test of the predictions of the Proportion of Total Duration (PTD) rule and the Component Relative Entropy (CoRE) model. Listeners had to decide whether two sequences of nine tones had the same or different temporal patterns (tone duration = 25 ms, tone frequency = 1000 Hz). A sequence's temporal pattern was determined by the time intervals between each tone's offset and the next tone's onset. On same trials, the time intervals at corresponding temporal positions in the two sequences were identical. On different trials, the corresponding time intervals were randomly varied. Listener attention to different temporal positions within a sequence was assessed by calculating the decision weights at each position. The results supported the CoRE model and were inconsistent with the PTD rule. Manipulating the mean of the time intervals within the sequence had no consistent effect on the pattern of weights (or on overall performance), indicating that listener attention was not affected by either the proportion of total duration or the perceptual salience of a longer or shorter time interval. However, manipulating the variance of the time intervals had a significant effect: the highest weight was given to the highest variance segment. This weighting strategy leads to better performance because higher variance segments are more diagnostic of whether the sequences are the same or different.     

Preventing expulsive hemorrhage using an anterior chamber maintainer to eliminate hypotony

We describe a method in which constant infusion inflow through an anterior chamber maintainer (ACM) is used to maintain positive intraocular pressure (IOP) during cataract extraction through a self-sealing tunnel incision. A retrospective review of patient records showed that the difference in the incidence of intraoperative suprachoroidal hemorrhage was significantly greater in eyes in which IOP was not constant throughout surgery than in eyes in which IOP was maintained using the ACM system.     

Monitor chamber backscatter for intensity modulated radiation therapy using multileaf collimators

Children are entitled to their cultural heritage and it is important to their development. Cultural considerations must be incorporated in devising custody and parenting plans. Several generalizations are useful. Children are capable of integrating highly diverse and even contradictory cultural and religious identity fragments. The more distinctly a child's cultural inheritance varies from that of the dominant society, the more it must be taken into account. The more bias or hostility that exists against an aspect of the child's cultural inheritance, the more that cultural component is to be considered. The value of culture to the child is best seen in a developmental context. We are limited in our ability to ensure children's rights to cultural inheritance by our own ethnocentrism or ignorance, by bureaucratic or legalistic definitions of cultural identity, by the desire of one parent to reduce the contribution of the other parent, and by a tendency to rely on consistency as a value in and of itself.     

Applicability to abrasion material of in vitro autoradiography, using 3H-thymidine (author's transl)

The applicability of in vitro autoradiography, using 3H-thymidine, was tested on material obtained from gynaecological abrasion. Included were 161 abrasion samples obtained from 151 patients, and 88 per cent of them proved evaluable by autoradiography. The use of in vitro autoradiography was found to give no additional gain in information for biological assessment. Index testing by means of in vitro autoradiography failed to prove worthwhile unless it came to examination of polyps or of glandular-cystic hyperplasia or of effects exerted on the endometrium by ovarian tumours with sizeable hormonal activity. Endometrium was found to be a kind of tissue characterised in both intact and pathological condition by pronounced individual age-dependent and cycledependent variations of its marking indices.     

Quantitative, competitive PCR assay for HIV-1 using a microplate-based detection system

OBJECTIVE: Amylin, a secretory peptide of beta-cells, is the constituent peptide of islet amyloid, which is characteristic of NIDDM, and changes in amylin secretion in response to therapies may influence the rate of production of islet amyloid. The primary objective of this study was to determine whether therapy with sulfonylurea or basal insulin in NIDDM would alter amylin secretion in a way that might affect the formation of islet amyloid. RESEARCH DESIGN AND METHODS: In a randomized crossover design, eight subjects with NIDDM underwent three 8-week periods of therapy with diet alone, sulfonylurea, or exogenous basal insulin, with evaluation of amylin, amylin-like peptide (ALP), and glucose and C-peptide concentrations, both during fasting and after a standard breakfast. Changes in beta-cell function (% beta) were assessed, in the basal state by homeostasis model assessment (HOMA) and in the stimulated state by hyperglycemic clamps. Seven nondiabetic control subjects each underwent a meal profile and hyperglycemic clamp. RESULTS: Both sulfonylurea and insulin therapy reduced basal glucose concentrations compared with diet alone, but neither reduced the increased postprandial glucose increments. Both sulfonylurea and insulin therapy increased basal % beta, assessed by HOMA, but only sulfonylurea increased the second-phase C-peptide responses to the hyperglycemic clamp. Sulfonylurea increased time-averaged mean postprandial amylin and ALP concentrations compared with diet alone (geometric mean [1-SD range] for amylin, 4.9 [2.0-11.8] vs. 3.0 [1.4-6.2] pmol/l, P = 0.003; for ALP, 16.4 [8.5-31.7] vs. 10.1 [4.9-20.8] pmol/l, P = 0.001). Insulin therapy reduced basal ALP concentrations compared with diet alone (2.9 [1.5-5.6] vs. 6.0 [2.6-13.6] pmol/l, P = 0.03), but had no effect on postprandial concentrations of amylin (3.0 [1.3-6.5] pmol/l) or ALP (10.0 [5.5-18.1] pmol/l). CONCLUSIONS: By increasing postprandial concentrations of the constituent peptides of islet amyloid, sulfonylurea therapy might increase the rate of deposition of islet amyloid and thereby accelerate the decline of % beta in NIDDM, compared with diet therapy alone.     

Calculation of exposure chamber leak rate with thermal correction: a measure of chamber integrity

RATIONALE AND OBJECTIVES: The authors prospectively tested the performance of a single numeric classifier constructed from a discriminative analysis classification system based on automatic computer-extracted quantitative features of clustered microcalcifications. MATERIALS AND METHODS: Mammographically detected clustered microcalcifications in patients who had been referred for biopsy were digitized at 600 dpi with an 8-bit gray scale. A software program was developed to extract features automatically from digitized images to describe the clustered microcalcifications quantitatively. The significance of these features was evaluated by using the Wilcoxon test, the Welch modified two-sample t test, and the two-sample Kolmogorov-Smirnov test. A discriminant analysis pattern recognition system was constructed to generate a single numeric classifier for each case, based on the extracted features. This system was trained on 137 archival known reference cases and its performance tested on 24 unknown prospective cases. The results were evaluated by using receiver operating characteristic analysis. RESULTS: Thirty-seven extracted parameters demonstrated a statistically significant difference between the values for the benign and for the malignant lesions. Seven independent factors were selected to construct the classifier and to evaluate the unknown prospective cases. The area under the receiver operating characteristic curve for the prospective cases was 0.88. CONCLUSION: A pattern recognition classifier based on quantitative features for clustered microcalcifications at screen-film mammography was found to perform satisfactorily. The software may be of value in the interpretation of mammographically detected microcalcifications.     

Quantitative evaluation of the rate of myocardial interstitial fibrosis using a personal computer

We investigated the reliability and reproducibility of an image-analyzing system run on a personal computer for measurement of myocardial interstitial fibrosis. Measurements of myocardial interstitial fibrosis in right ventricular endomyocardial biopsies obtained from patients with hypertrophic cardiomyopathy determined by this image-analyzing system were compared with measurements determined by the point-counting method. We also investigated the correlation between measurements of interstitial fibrosis obtained by image analysis and biochemical measurements of myocardial levels of hydroxyproline in normal and cardiomyopathic hamsters. The intra- and interobserver variability were significantly lower for measurements obtained by the image-analyzing system than for measurements obtained by the point-counting system. Reproducibility was superior with the image-analyzing method. The rate of myocardial interstitial fibrosis determined by the computer image-analyzing method was positively correlated with the hydroxyproline measurement (r = 0.89). Our results suggest that an image-analyzing system using a personal computer provides reproducible results with a high level of reliability.