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PubMed1987

Rapid determination of five coagulation parameters in one sample with a centrifugal analyzer.

Spectrophotometric clotting assays using chromogenic substrates were adapted for use in a routine laboratory batch analyzer. Contrary to another described method the same plasma dilution can be used for each of the different coagulation parameters. Optimal assay conditions were determined. The within- and between-assay variation, the intraindividual variation during 1 day and from month-to-month were determined; the chromogenic assay was compared to a clotting assay. No significant difference (p less than 0.01) between manual and automated methods was found.

Antithrombin III↗
PubMed1978

Same/different concept learning in the pigeon: the effect of negative instances and prior adaptation to transfer stimuli.

Pigeons were trained on a matching-to-sample or oddity-from-sample task with shapes (circle and plus). Half of each group was exposed to "negative instance" trials i.e., for matching birds, neither comparison key matched the sample, and for oddity birds both comparison keys matched the sample. When all birds were transferred to a new task involving colors (red and green), nonshifted birds (transferred from matching to matching, or oddity to oddity) performed significantly better than shifted birds (transferred from matching to oddity, or oddity to matching), but only if they had experienced negative instances of the training concept. When all birds were exposed to negative instances of the transfer task and then transferred to a new color task (yellow and blue), dramatic transfer effects were observed. The effect of pre-exposure to the yellow and blue colors, in order to reduce transfer-stimulus novelty, had a minor effect on transfer.

Journal Article↗
PubMed1997

Substance abuse and homelessness: social selection or social adaptation?

Although substance abuse has for many years been documented as a serious problem among homeless populations, there is as yet no clear understanding of the nature of the relationship between substance abuse and homelessness. We evaluate alternative social selection and social adaptation models of this process. Using data from a random probability sample, the substance abuse and homeless experiences of 303 homeless people and people at risk of homelessness in Cook County, Illinois, were investigated. Proportional hazards regression models were employed to assess both social selection and social adaptation models. Drug but not alcohol abuse was associated with first homeless episode. Prior homeless experiences were found to be predictive of first symptoms of both alcohol and drug abuse. Other variables, including the availability of social and economic resources, were also associated with each of these outcomes. Models of both selection and adaptation processes are necessary to account for the association between homelessness and substance abuse, indicating that a multi-directional model is more appropriate. In addition findings suggest that, in recent years, drugs may have displaced alcohol as an important precursor of homelessness for many individuals.

Adolescent↗
PubMed2005

A refined long RT-PCR technique to amplify complete viral RNA genome sequences from clinical samples: application to a novel hepatitis C virus variant of genotype 6.

The goal of this study was to adapt a long RT-PCR technique to amplify large PCR fragments from the genome of hepatitis C virus (HCV) isolates using clinical samples. This was done by using a reverse transcriptase devoid of RNase H activity and a mixture of two antibody-bound thermostable polymerases to combine the high processivity of Taq and the high fidelity of Pwo with its 3'-->5' exonuclease activity. Other modifications included gentle handling during RNA extraction, the absence of tRNA and random primers, a two-step reverse transcription procedure to optimize cDNA synthesis, and increasing the annealing temperature for primers. With this approach, the HCV-1 genome (nucleotides 35-9282) was amplified consistently as two overlapping fragments of 5344 and 4675 bp from a pooled chimpanzee plasma sample containing approximately 10(6) genome copies of HCV RNA/ml. Using the conditions that we identified, 96% of the complete genomic sequence of a distinct HCV genotype 6 variant (km45) was determined from less than 300 microl of serum. This method should prove useful for molecular, epidemiological and clinical studies of hepatitis C where samples are limited but complete virus sequence is required, for example, identifying mutational hot spots of HCV under specific clinical conditions.

Animals↗
PubMed2006

Identification of genetic loci that regulate bone adaptive response to mechanical loading in C57BL/6J and C3H/HeJ mice intercross.

Strain-dependent differences in bone adaptive responses to loading among inbred mouse strains suggest that genetic background contributes significantly to adaptation to exercise. To explore the genetic regulation of response to loading, we performed a genome-wide search for linkage in a cross between two strains, a good responder, C57BL6/J (B6), and a poor responder, C3H/HeJ (C3H). Using a four-point bending model, the right tibia was loaded by applying 9 N force for 36 cycles for 12 days in 10-week-old female B6xC3H F2 mice. Changes in bone density (BMD) and bone size were evaluated in vivo by pQCT. Measurements from non-loaded left tibia were used as an internal control to calculate loading-induced percent increase in BMD and bone size, thus excluding the possibility of identifying background QTL(s) due to natural allelic variation in mapping strains. A genome-wide scan was performed using 111 microsatellite markers in DNA samples collected from 329 F2 mice. Heritability of bone adaptive response to loading was between 70 and 80%. The mean increase, expressed as percent of unloaded tibia, was 5% for BMD, 9% for periosteal circumference (PC), and 14% for cortical thickness in F2 mice (n = 329). All these phenotypes showed normal distributions. Absence of significant correlation between BMD response to four-point bending and body weight or bone size suggested that the bone adaptive response was independent of bone size. Interval mapping revealed that BMD response to four-point bending was influenced by three significant loci on Chrs 1 (log-of-odds ratio score (LOD) 3.4, 91.8 cM), 3 (LOD 3.6, 50.3 cM), and 8 (LOD 4.2, 60.1 cM) and one suggestive QTL on Chr 9 (LOD 2.5, 33.9 cM). Loading-induced increases in PC and Cth were influenced by four significant loci on Chrs 8 (LOD 3.0, 68.9 cM), 9 (LOD 3.0, 13.1 cM), 17 (LOD 3.0, 39.3 cM), and 18 (LOD 3.0, 0 cM) and two suggestive loci on Chr 9 (LOD 2.2, 24 cM) and 11 (LOD 2.1, 69.9 cM). Pairwise analysis showed the presence of several significant and suggestive interactions between loci on Chrs 1, 3, 8, and 13 for BMD trait. This is the first study that provides evidence for the presence of multiple genetic loci regulating bone anabolic responses to loading in the B6xC3H intercross. Knowledge of the genes underlying these loci could provide novel approaches to improve skeletal mass.

Adaptation, Biological↗
PubMed1987

A rapid and precise assay for calmodulin and cyclic AMP phosphodiesterase on a centrifugal analyser.

An assay for cyclic AMP phosphodiesterase in biological samples is described. The method is a continuous, spectrophotometric assay adapted for use on a centrifugal analyser. Using the calmodulin-activated cyclic AMP phosphodiesterase prepared from pig brain by DEAE-cellulose chromatography, and a standard calmodulin preparation from the same source, a rapid assay for calmodulin is described. The calmodulin assay has a working range of 2 to 6 mg/l calmodulin in the sample. The within-batch CV is less than 5% and the between-batch CV is 7.0% or less.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

Application of amino acid analysis by high-performance liquid chromatography with phenyl isothiocyanate derivatization to the rapid determination of free amino acids in biological samples.

An amino acid analysis by reversed-phase high-performance liquid chromatography after precolumn derivatization with phenyl isothiocyanate was adapted to the determination of free amino acids in plasma or other biological fluids and in tissue homogenates. Preparation of samples included deproteinization by 3% sulphosalicylic acid, and careful removal under high vacuum of residual phenyl isothiocyanate after derivatization. A Waters Pico-Tag column (15 cm long) was used, immersed in a water-bath at 38 degrees C. In rat or human plasma, separation of 23 individual amino acids, plus the unresolved pair tryptophan and ornithine, was obtained within 13 min. Including the time for column washing and re-equilibration, samples could be chromatographed at 23-min intervals. Variability was tested for each amino acid by calculating the coefficients of variation of retention times (less than 1% in the average) and peak areas (less than 4% for both intra-day and inter-day determinations). The linearity for each standard amino acid was remarkable over the concentration range 3-50 nmol/ml. The mean recovery of amino acid standards added to plasma prior to derivatization was 97 +/- 0.8%, except for aspartate (82%) and glutamate (81%). This method is rapid (almost three samples per hour can be analysed, more than in any other reported technique), with satisfactory precision, sensitivity and reproducibility. Therefore, it is well suited for routine analysis of free amino acids in both clinical and research work.

Amino Acids↗
PubMed2006

The prevalence of phobia and its associated factors in a multiracial aging urban population.

OBJECTIVE: There have been few multiracial epidemiologic community-based studies of phobia in older adults. The aim of this study was to determine the prevalence of phobia and associated factors among older persons living in a northeastern urban area. METHODS: Using 1990 census data for Brooklyn, NY, the authors attempted to interview all persons age 55+ in randomly selected block groups. The final sample consisted of 214 whites and 860 blacks. The authors used an adaptation of George's Social Antecedent Model for examining the association of 18 individual variables and one interactive variable with the presence of a phobia. The dependent variable was derived from the Guy's/Age Concern community survey. The sample was weighted by race and gender. To control for design effects, the authors used SUDAAN for the data analysis. RESULTS: A total of 8.9% of the sample met criteria for a current phobia and 10.2% met phobia criteria at some time during their life. Using logistic regression analysis, the authors found six variables-higher personal income, more depressive symptoms, poorer physical health, use of prayer as a coping strategy, use of spiritualists or their products, and not having been raised by both parents-to be significantly associated with a current phobia. CONCLUSION: The prevalence rate of phobia was comparable to rates for older adults in the urban areas of the Epidemiologic Catchment Area study suggesting that prevalence has remained stable over the past two decades. Consistent with earlier studies, there were significant associations among phobia, depressive symptoms, and physical illness. Many of the demographic and social variables, including race, that had been reported previously to be associated with phobias in younger samples were not significant in this study.

Adaptation, Psychological↗
PubMed1988

Plasma creatine determination using a luminescence method.

A new luminescence procedure based on the creatine kinase reaction was developed for measuring creatine in plasma. The method is highly applicable to small animal work where the amount of blood volume is critical. Only 20 microliter of sample is necessary for creatine analysis. Deproteinizing the plasma sample with ethanol at room temperature is convenient. This extraction method is adaptable to a clinical setting. The ethanol used in the extraction is compatible with the luminescence method but precipitated enzymes in the NADH spectrophotometric method because of the greater sample volume needed for analysis. The creatine concentration is stable in plasma for at least 1 hr in a final anticoagulant concentration of 10 mM EDTA. The correlation between the new luminescence method with the established NADH spectrophotometric method was excellent (r = 0.99). The accuracy of the within-run precision is high, with a mean coefficient of variation, 2-3%. Plasma creatine levels could be an important indicator denoting early cellular damage and of potential prognostic value. Preliminary studies in human muscle ischemia and early shock in rabbits revealed a significant increase in plasma creatine levels. Further investigations are necessary to evaluate its clinical importance.

Creatine↗
PubMed1984

The behavior inventory for rating development (BIRD): assessments of reliability and factorial validity.

In an earlier investigation (Sparrow & Cicchetti, 1978) the authors assessed the reliability and validity of a new instrument for assessing types and levels of adaptive behaviors. Although there was strong evidence for both, the sample was small (N = less than or equal to 45) and consisted only of institutionalized mentally retarded children. The current investigation included a much larger sample of non-institutionalized mentally retarded and other developmentally disabled subjects. As previously, results indicated reliability levels between "good" and "excellent" for most items (e.g., the criteria of Cicchetti & Sparrow, 1981). Also, factor analyses were performed to determine the correlation between the resulting factors and an a priori classification of the BIRD into several areas (subscales) of adaptive behavior (Cognitive Development, Self-Help, Physical Development, Social Behavior, Self-Control). As before, a 4 factor oblique solution was interpretable in terms of a 4 subscale classification of BIRD items (Cognitive Development, Physical Development, Social Behavior, and Self-Control).

Adolescent↗
PubMed1982

Allometry and adaptation in the catarrhine postcranial skeleton.

Seven measurements were taken on the postcranial skeleton of 249 specimens representing ten species of catarrhine primates and tested to determine their relationship with size. Size was measured as skeletal weight on each individual. It was found that the interspecific line based on the entire sample was in some cases determined not only by morphological adjustments for size variation but also by changes in locomotor adaptations of differently sized species within the sample. It is suggested that it is consequently preferable to study allometric relationships within a species or within a group of species that differ in size but are similar in their mode of locomotion. The allometric analysis reveals some interesting patterns within the data. Limb lengths scaled with either negative allometry or isometry over the entire sample. Within the species groups isometry was the rule except for pongid femurs, which showed negative scaling. Humerus length scaled at the same rate in pongids as in cercopithecoids but had a slightly higher intercept value. While colobines and cercopithecines scaled at similar rates for all seven dimensions, the colobine line was shifted to a position above that for cercopithecines in every case. It is suggested that this is a result of adaptation for leaping in the former group. Other implications of the allometric results are discussed.

Adaptation, Physiological↗
PubMed1990

[Manifestations of adaptive processes in the epithelium of the renal glomerular filter].

Fifteen kidney biopsy samples+, obtained from children suffering from the primary nephrotic syndrome, characterized with a high selective proteinuria and non-inflammatory character of changes in the renal corpuscles have been investigated after hormonotherapy (11 cases before and 4 cases 2-3 weeks after it). In podocytes certain disturbances in the lysosomal-vascular apparatus develop with a successive appearance of degeneration, desquamation and even necrosis of these cells. After prednisolone++ treatment edema of cytoplasm of the cells and their processes disappears, amount and size of the filtration slits are partly restored.

Adaptation, Physiological↗
PubMed1987

Central catecholamines, cognitive impairment, and affective state in elderly schizophrenics and controls.

Central catecholamine concentrations were determined in autopsy samples from older schizophrenic and control subjects for both the hypothalamus and the nucleus accumbens. The results of these analyses and demographic variables were regressed on antemortem measures of cognitive function and mood state. In the hypothalamus, there are significant direct relationships of homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) with depressed mood, as measured by an adaptation of the Hamilton Rating Scale for depression. In the nucleus accumbens, dopamine (DA) and MHPG had significant inverse relationships with antemortem cognitive function, as measured by an adaptation of the Mini Mental State Exam. Results in this sample indicate that after controlling for age, the catecholamine concentrations accounted for approximately 50% of the variance in the antemortem measures of mood or cognition, depending on the loci measured.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1986

Normalized noise energy as an acoustic measure to evaluate pathologic voice.

In order to evaluate noise components included in pathologic voice signals, a novel acoustic measure, normalized noise energy (NNE), is proposed and its effectiveness for the detection of laryngeal pathologies is investigated with 250 vowel samples spoken by 64 control (normal) subjects and 186 patients with various laryngeal diseases. The NNE is automatically computed from the voice signals using an adaptive comb filtering method performed in the frequency domain. Experiments with the voice samples show that the NNE is especially effective for detecting glottic cancer, recurrent nerve paralysis, and vocal cord nodules. Specifically, when glottic cancer is represented in terms of the T classification adopted by the UICC (Union Internationale Contre le Cancer), glottic T2-T4 cancer can be perfectly discriminated from normal samples, but 22.6% of patients with glottic T1 cancer are incorrectly classified as normal, with an error rate of 9.4% for normal subjects.

Glottis↗
PubMed1984

High-pressure-temperature gradient instrument: use for determining the temperature and pressure limits of bacterial growth.

A pressurized temperature gradient instrument allowed a synoptic determination of the effects of temperature and pressure on the reproduction of bacteria. The instrument consisted of eight pressure vessels housed parallel to each other in an insulated aluminum block in which a linear temperature gradient was supported. For a given experiment, eight pressures between 1 and 1,100 bars were chosen; the linear temperature gradient was established over an interval within -20 to 100 degrees C. Pure cultures and natural populations were studied in liquid or solid medium either in short (ca. 2-cm) culture tubes or in long (76.2-cm) glass capillaries. In the case of a pure culture, experiments with the pressurized temperature gradient instrument determined values of temperature and pressure that bounded its growth. Feasibility experiments with mixed populations of bacteria from water samples from a shallow depth of the sea showed that the instrument may be useful in identifying the extent to which a natural population is adapted to the temperatures and pressures at the locale of origin of the sample. Additional conceived uses of the instrument included synoptic determinations of cell functions other than reproduction and of biochemical activities.

Bacteria↗
PubMed2026

Evaluation and Optimization of Different Digestion Strategies for In-Depth Proteomic Characterization of Residual Host Cell Proteins in rAAV-Based Gene Therapy Products.

Recombinant adeno-associated virus vectors (rAAVs) are the most important vectors for in vivo gene therapies, yet their safety relies on low levels of residual host cell proteins (HCPs). While mass spectrometry-based proteomics enables sensitive and untargeted HCP profiling, it faces challenges with matrix interferences from purification buffers and the high dynamic range between abundant viral capsids and trace HCPs. Although sample preparation methods that address these challenges are well-established for antibody products, their adaptation to rAAV purification stages and products remains largely unexplored. In this study, we systematically evaluated three widely used proteomic sample preparation workflows─In-Solution, FASP, and SP3─across different stages of rAAV purification. In addition, each workflow was tested under both standard denatured digestion conditions and a "native" digestion strategy designed to reduce dynamic range by preserving capsid integrity while selectively digesting HCPs. This comparison identified the native FASP protocol as the most effective sample preparation method for overcoming matrix interference and dynamic range challenges, consistently outperforming other workflows in HCP identification across purification stages. Further optimization of the native FASP workflow enhanced its performance, achieving the highest host cell (HC) proteome depth, particularly in highly purified drug substance samples. This optimized sample preparation strategy provides a robust and easy-to-use framework for deep characterization of the host cell proteome in rAAV samples. By enabling deeper insights into the HCP profile, this approach supports improved understanding of the rAAV purification process and facilitates the development of targeted strategies to enhance product quality and safety.

Dependovirus↗
PubMed1991

Symptom schemata in chronic respiratory patients.

In view of evidence that illness prognoses and adaptive functioning may be influenced by the accuracy of people's knowledge about their physical symptoms, the present study extended these findings to the chronic care population. It was hypothesized that individuals hold beliefs and develop theories about their physical symptoms and that the accuracy of these beliefs is predictive of the individuals' general level of adaptive functioning. A modified version of an instrument designed to measure the accuracy of illness schemata was employed with a sample of 31 chronic respiratory patients. Accuracy rating correlated positively and significantly with ratings of adaptive functioning, whereas no relationship was observed between adaptive functioning and severity of the patients' medical condition. Well-informed patients functioned at a higher level physically, psychologically, and socially than less-informed patients. These findings point to the importance of patient education for prognosis. Possible mediating factors are discussed.

Adult↗
PubMed2004

Spectral characterization of a color scanner by adaptive estimation.

A new method of spectral characterization for color scanners by the use of adaptive estimation is proposed. It deals with estimation of high-dimensional reflectance vectors from low-dimensional scanner response vectors when the scanner departs from linearity. We first investigate the spectral linearity of the scanner, and then estimate the spectral reflectance adaptively based on the local statistics of a set of neighboring training samples. As the proposed characterization method does not utilize the mathematically recovered spectral responsivity, its inherent inaccuracy is not critical to the spectral characterization. Experimental results showed significant advantage of adaptive estimation when compared with other methods.

Journal Article↗