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PubMed1995

Laser profiling: a technique for the study of prosthetic heart valve leaflet motion.

A detailed understanding of the stresses and strains developed in functioning flexible-leaflet valves is necessary if a durable, non-thrombogenic heart valve replacement is to be realized. A new experimental tool, laser profiling, is presented for the study of flexible-leaflet heart valve dynamics. Profiles of moving leaflet surfaces are obtained by projecting parallel sheets of laser light onto valve leaflets as the valves open and close in a mock circulatory loop. Two versions of laser profiling have been developed. In two-dimensional mode multiple profiles are generated on a fixed plane in space but at discrete intervals in time, whereas in three-dimensional mode multiple profiles are generated across the leaflet surface at (effectively) a single instant in time. Highlighted leaflet profiles are captured by camera and transferred to an image processing system for analysis. A simple algorithm permits digitized profiles to be reconstructed within a computer-aided design software package, providing detailed visualization and quantification of valve motion. Extensive validation studies have been performed using the Medtronic-Hall mechanical prosthetic heart valve. Laser profiling enables computer reconstruction of the rigid occluder to an accuracy of +/- 200 microns from a 0.7 ms exposure taken during the period at which the occluder moves with greatest velocity. The technique has been applied to investigate the leaflet dynamics of a bovine pericardial heart valve prosthesis.

Acoustic Stimulation↗

PubMed1996

Staple leg profile influence on pullout strength: a biomechanical study.

Bone staples have widespread applicability in orthopaedic surgery. Their use, however, is limited by inconsistent quality of fixation. Prior studies have shown potential for improvement in the reliability of staple fixation through a change in the design of the staple legs. To identify a superior leg cross section profile, pullout strength of 5 different newly designed staple leg cross sections were evaluated in fresh frozen human cadaveric bones before and after toggle loading. The tests were repeated in a synthetic bone model with variable but consistent densities. The curvilinear square profile had the highest pullout strength in both the cadaveric and synthetic bone, followed in descending order by square, circular, and triangular profiles. Controlling for density, the pullout strength of the curvilinear square profile was 8% higher than the square profile and 34% higher than the circular profile. The triangular profiles had the least resistance to pullout force before and after cyclic loading. The curvilinear square may be the best profile for the cross section of the staple leg for maximum pullout strength and may expand the clinical use of staples in bone fixation.

Adult↗

PubMed1999

Long-term stability of Child Behavior Checklist profile types in a child psychiatric clinic population.

OBJECTIVE: To study the long-term stability of Child Behavior Checklist (CBCL) profile types, which represent children's overall patterns of single and comorbid scale elevations. METHOD: Profile types were determined for 623 outpatient children at referral and then at mean follow-up 4.8 years later, and their continuity was determined. RESULTS: At baseline 37.5% of the children were classified by a profile type, and 41.9% of these originally classified children continued to be classified at follow-up. The average odds ratio for a child continuing as a specific CBCL profile type from baseline to follow-up was 8.2. When children changed from one specific profile type to another, they usually continued in the same broad externalizing or internalizing category. Children who were not classified by a profile type at baseline generally remained unclassified. CONCLUSIONS: Stability findings for CBCL profile types appeared good and were similar to past longitudinal results for CBCL scales and DSM diagnoses. These profile types may prove an important empirical method for addressing the problem of comorbid clinical pictures.

Adolescent↗

PubMed2006

Patients undergoing sinus surgery: constructing a demographic profile.

OBJECTIVES: The objective of this study is to construct an accurate and representative demographic profile of patients undergoing sinus surgery for chronic rhinosinusitis (CRS). This will enable future studies to enroll representative samples so that results can be more easily compared across studies and generalized to the U.S. population. METHODS: The investigators interrogated the databases of the National Survey of Ambulatory Surgery to gather demographic data. Whenever the NSAS provided incomplete characterization, deficiencies were corrected using state-level data provided by the Health care Cost and Utilization Project. The constructed profile was compared with available profiles of patients with CRS and demographic data provided by the U.S. Census Bureau. RESULTS: The demographic profile of patients undergoing sinus surgery is 52.7% female with a mean age of 38.5 years. A total of 93.5% of surgery is performed on an outpatient basis with 78.8% of patients having private insurance sources. No significant difference in occurrence of surgery was found between months of the year or between regions of the country. The constructed race profile is 85.7% white, 5% black, 1.2% Asian/Pacific Islander, 0.2% Native American, and 7.8% other. CONCLUSIONS: A novel integration of national and state databases can be used to create a demographic profile of patients undergoing surgery for CRS. The creation of this profile enables further study of representative populations of patients with CRS and enables thoughtful analysis of the existing literature. The difficulty in creating the profile highlights the need for complete and accurate healthcare information collection by national and state agencies.

Adolescent↗

PubMed2006

Cytokeratins 7 and 20 in primary and secondary mucinous tumors of the ovary: analysis of coordinate immunohistochemical expression profiles and staining distribution in 179 cases.

Coordinate expression profiles for cytokeratins 7 and 20 (CK7 and CK20) are useful for distinguishing certain types of adenocarcinomas but use for distinction of primary and secondary mucinous tumors in the ovary is limited due to the existence of a number of tumor types exhibiting overlapping CK7/CK20 immunoprofiles; the use of staining distribution patterns in the distinction of tumors with shared profiles has not been evaluated in detail. We report analysis of both coordinate expression profiles and staining distribution in 179 rigorously classified mucinous tumors in the ovary, including 53 primary tumors [35 atypical proliferative (borderline) mucinous tumors of gastrointestinal type and 18 invasive mucinous carcinomas] and 126 secondary tumors [28 colorectal adenocarcinomas, 54 appendiceal tumors (23 adenocarcinomas, 31 low-grade adenomatous mucinous tumors associated with pseudomyxoma peritonei), 14 pancreatic adenocarcinomas, 8 endocervical adenocarcinomas, 5 gastric adenocarcinomas, 4 gallbladder/biliary tract adenocarcinomas, and 13 adenocarcinomas of unknown primary sites). A CK7+/CK20+ immunoprofile was the most common profile in primary ovarian tumors (74%), upper gastrointestinal tract tumors (78%), and endocervical tumors (88%) but was occasionally observed in lower intestinal tract tumors (colorectal: 11%; appendiceal: 13% of low-grade tumors, 35% of carcinomas). A CK7-/CK20+ immunoprofile was the most common profile in lower intestinal tract tumors (79%) and was uncommon in upper gastrointestinal tract tumors (9%), rarely seen in primary ovarian tumors (4%), and not seen in endocervical tumors. A CK7+/CK20- profile was observed in some primary ovarian (23%), upper gastrointestinal tract (13%), and endocervical tumors (13%) but not in lower intestinal tract tumors. For CK7+ tumors, staining distribution was very frequently diffuse (>50% of tumors cells positive) in primary ovarian, upper gastrointestinal tract, and endocervical tumors, whereas staining distribution was often focal (<50% of tumors cells positive) when present in colorectal and appendiceal carcinomas but not in low-grade appendiceal tumors. For CK20+ tumors, staining distribution was variable but often focal in primary ovarian tumors and nonlower intestinal tract tumors, whereas the pattern was almost always diffuse in lower intestinal tract tumors. Immunohistochemical staining distribution can supplement CK7/CK20 coordinate expression profiles to distinguish subsets of primary ovarian and metastatic lower intestinal tract mucinous tumors having overlapping immunoprofiles but neither coordinate expression profiles nor staining distribution distinguishes primary ovarian tumors from the nonlower intestinal tract metastases.

Adenocarcinoma↗

PubMed1997

The Determination of Relative Elemental Growth Rate Profiles from Segmental Growth Rates (A Methodological Evaluation).

Relative elemental growth rate (REGR) profiles describe spatial patterns of growth intensity; they are indispensable for causal growth analyses. Published methods of REGR profile determination from marking experiments fall in two classes: the profile is either described by a series of segmental growth rates, or calculated as the slope of a function describing the displacement velocities of points along the organ. The latter technique is usually considered superior for theoretical reasons, but to our knowledge, no comparative methodological study of the two approaches is currently available. We formulated a model REGR profile that resembles those reported from primary roots. We established the displacement velocity profile and derived growth trajectories, which enabled us to perform hypothetical marking experiments on the model with varying spacing of marks and durations of measurement. REGR profiles were determined from these data by alternative methods, and results were compared to the original profile. We find that with our model plotting of segmental relative growth rates versus segment position provides exact REGR profile estimations, if the initial segment length is less than 10% of the length of the whole growing zone, and if less than 20% of the growing zone is displaced past its boundary during the measurement. Based on our analysis, we discuss systematic errors that occur in marking experiments.

Journal Article↗

PubMedDate not supplied

The immediate effect of colposuspension on resting and stressed urethral pressure profiles in anaesthetized incontinent bitches.

The aim of this study was to document what changes in the resting and stressed urethral pressure profile occur in the incontinent bitch with urethral sphincter mechanism incompetence (SMI) immediately after colposuspension. Resting and stressed subtracted simultaneous urethral pressure profilometry was performed immediately pre- and postcolposuspension in 26 bitches diagnosed with SMI. All of the urethral pressure profiles were measured in anaesthetized bitches using a standard technique and two orientations of the catheter transducers (dorsal and left). Readable pre- and postoperative urethral pressure profiles were obtained in 20 of the 26 bitches. Subjective and objective evaluation of the profiles showed significant differences in the profiles pre- and postcolposuspension. Immediately postoperatively there were significant (P < .05) increases in functional profile length, maximum urethral closure pressure (MUCP), and distance between the bladder neck and the first negative respiratory peak and stressed spike. There was a significant (P < .001) decrease in the percentage of negative spikes extending below the resting intravesical pressure on the subtracted profile. The pressure transmission profiles were significantly (P < .001) altered by surgery. The findings presented support the hypothesis that colposuspension may restore continence by increasing pressure transmission to the proximal urethra and bladder neck. The results also suggest that immediately after surgery functional urethral length and urethral resistance are increased.

Analysis of Variance↗

PubMed2026

Influence of Concave Versus Convex Emergence Profiles on Midfacial Mucosal Stability-A Systematic Review With Meta-Analysis.

OBJECTIVES: To systematically evaluate the influence of concave versus convex emergence profiles on midfacial mucosal stability in partially edentulous patients restored with implant-supported single restorations. MATERIALS AND METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted and registered in PROSPERO (CRD420251139042). An electronic search in MEDLINE (PubMed) and Embase was performed up to May 7, 2026. Eligible studies included RCTs comparing concave (test group) and convex (control group) transmucosal prosthetic designs and reporting midfacial mucosal level changes (mm). Data extraction and risk of bias assessment (RoB 2) were performed independently. A random-effects meta-analysis was conducted using weighted mean differences (MDs) and 95% confidence intervals (CIs). Heterogeneity was assessed using the I2 statistic and sensitivity analyses were performed to evaluate the robustness of the findings. RESULTS: Four RCTs including 144 implants with a 12-month follow-up were included. Of these, 128 implants contributed to the quantitative synthesis, with 66 implants allocated to the concave/modified emergence profile group and 62 implants allocated to the convex/non-concave emergence profile group. The pooled analysis demonstrated a mean difference of -0.31 mm (95% CI -0.63 to 0.02; p = 0.064), indicating a trend toward greater midfacial mucosal recession with convex emergence profiles compared with concave designs. Between-study heterogeneity was low to moderate (I2 = 28%), suggesting consistent findings across studies. Sensitivity analyses confirmed the direction of the effect, with pooled estimates ranging from -0.12 to -0.43 mm. Exclusion of one study resulted in a statistically significant difference favoring concave emergence profiles (-0.43 mm; 95% CI -0.70 to -0.16; p = 0.002). CONCLUSIONS: Convex emergence profiles are associated with a tendency toward increased midfacial mucosal recession. Concave profiles are preferable to support peri-implant soft-tissue stability. CLINICAL RELEVANCE: Emergence profile design should be considered an integral component of prosthetic and surgical planning. The use of concave transmucosal contours during provisionalization and definitive restoration may contribute to improved peri-implant soft tissue stability and enhanced esthetic outcomes.

Humans↗

PubMed1999

Experimental determination of section sensitivity profiles and image noise in electron beam computed tomography.

To determine the effect of continuous-volume scanning (CVS) on z-axis resolution, section sensitivity profiles were measured on an electron beam computed tomography (CT) scanner and compared with those obtained using the step-volume scanning (SVS) mode. A steel bead was imaged using different scan parameters, and the mean CT number over the bead was plotted against the z-axis position to determine section sensitivity profiles. From these profiles, full width at half maximum (FWHM), full width at tenth maximum (FWTM), and full width at tenth area (FWTA) were calculated. A uniform water phantom was imaged to measure noise. To determine the visual significance of changes in the section sensitivity profile, a section thickness and contiguity phantom was imaged. All section sensitivity profiles measured had an FWHM value within 0.5 mm of the nominal scan width. The FWTM and FWTA values increased with the CVS mode compared with the SVS mode. This broadening of the section sensitivity profiles was most significant with larger collimator widths. However, use of smaller collimator widths increased image noise. When all other parameters remained constant, increasing the exposure time to reduce image noise did not affect the section sensitivity profile. The CVS mode produced wider section sensitivity profiles than the SVS mode. This effect was minimized when the smallest collimator width was used, but at the expense of increased image noise.

Electrons↗

PubMed2002

Polymorphic variants (CYP2C93 and CYP2C95) and the F114L active site mutation of CYP2C9: effect on atypical kinetic metabolism profiles.

CYP2C9 wild-type protein has been shown to exhibit atypical kinetic profiles of metabolism that may affect in vitro-in vivo predictions made during the drug development process. Previous work suggests a substrate-dependent effect of polymorphic variants of CYP2C9 on the rate of metabolism; however, it is hypothesized that these active site amino acid changes will affect the kinetic profile of a drug's metabolism as well. To this end, the kinetic profiles of three model CYP2C9 substrates (flurbiprofen, naproxen, and piroxicam) were studied using purified CYP2C9*1 (wild-type) and variants involving active site amino acid changes, including the naturally occurring variants CYP2C9*3 (Leu359) and CYP2C9*5 (Glu360) and the man-made mutant CYP2C9 F114L. CYP2C9*1 (wild-type) metabolized each of the three compounds with a distinctive profile reflective of typical hyperbolic (flurbiprofen), biphasic (naproxen), and substrate inhibition (piroxicam) kinetics. CYP2C9*3 metabolism was again hyperbolic for flurbiprofen, of a linear form for naproxen (no saturation noted), and exhibited substrate inhibition with piroxicam. CYP2C9*5-mediated metabolism was hyperbolic for flurbiprofen and piroxicam but linear with respect to naproxen turnover. The F114L mutant exhibited a hyperbolic kinetic profile for flurbiprofen metabolism, a linear profile for naproxen metabolism, and a substrate inhibition kinetic profile for piroxicam metabolism. In all cases except F114L-mediated piroxicam metabolism, turnover decreased and the K(m) generally increased for each allelic variant compared with wild-type enzyme. It seems that the kinetic profile of CYP2C9-mediated metabolism is dependent on both substrate and the CYP2C9 allelic variant, thus having potential ramifications on drug disposition predictions made during the development process.

Alleles↗

PubMed1995

Fatty Acid methyl ester profiles for characterization of glomalean fungi and their endomycorrhizae.

Arbuscule-forming fungi in the order Glomales form obligate endomycorrhizal associations with plants that make them difficult to quantify, and taxonomy of the group is only beginning to be objectively understood. Fatty acid methyl ester (FAME) profiles were analyzed to assess the diversity and quantity of fatty acids in 53 isolates of 24 glomalean species. Spores and endomycorrhizal roots of sudan grass (Sorghum sudanense) and the citrus rootstock Carrizo citrange (Poncirus trifoliata x Citrus sinensis) were examined. Spores yielded reproducible FAME profiles from replicate spore collections extracted from soil pot cultures despite being grown in association with a host plant and with contaminating microorganisms present. Unweighted pair group analysis revealed relatively tight clusters of groups at the intraspecific, specific, and generic levels; however, lipid profiles at the family level were convergent. Thus, FAME profile comparisons provided a robust measure of similarity below the family level. FAME profiles in sudan grass roots containing vesicles and/or spores of Glomus intraradices were more similar to spore profiles than to profiles from nonmycorrhizal roots. The FAME profiles for Gigaspora species, which do not form vesicles or spores in roots, were less distinct from nonmycorrhizal roots. G. intraradices and G. rosea produced fatty acids in roots that were distinguishable from each other as well as from the host root. Production in citrus roots of the fatty acid 16:1(inf(omega)5) cis by two Glomus species was correlated with the development of mycorrhizal colonization as measured by clearing and staining procedures and by estimates of total incidence and vesicle intensity. FAME analysis of roots not only provided a measure of colonization development but also served as an index of carbon allocated to intraradical fungal growth and lipid storage.

Journal Article↗

PubMed2001

Percent G+C profiling accurately reveals diet-related differences in the gastrointestinal microbial community of broiler chickens.

Broiler chickens from eight commercial farms in Southern Finland were analyzed for the structure of their gastrointestinal microbial community by a nonselective DNA-based method, percent G+C-based profiling. The bacteriological impact of the feed source and in-farm whole-wheat amendment of the diet was assessed by percent G+C profiling. Also, a phylogenetic 16S rRNA gene (rDNA)-based study was carried out to aid in interpretation of the percent G+C profiles. This survey showed that most of the 16S rDNA sequences found could not be assigned to any previously known bacterial genus or they represented an unknown species of one of the taxonomically heterogeneous genera, such as Ruminococcus or Clostridium. The data from bacterial community profiling were analyzed by t-test, multiple linear regression, and principal-component statistical approaches. The percent G+C profiling method with appropriate statistical analyses detected microbial community differences smaller than 10% within each 5% increment of the percent G+C profiles. Diet turned out to be the strongest determinant of the cecal bacterial community structure. Both the source of feed and local feed amendment changed the bacteriological profile significantly, whereas profiles of individual farms with identical feed regimens hardly differed from each other. This suggests that the management of typical Finnish farms is relatively uniform or that hygiene on the farm, in fact, has little impact on the structure of the cecal bacterial community. Therefore, feed compounders should have a significant role in the modulation of gut microflora and consequently in prevention of gastrointestinal disorders in farm animals.

Animal Feed↗

PubMed1998

Scanning laser tomography Z profile signal width as an objective index of macular retinal thickening.

AIMS: (i) To evaluate the relation between retinal thickness and the Z profile signal width of a scanning laser tomographer in selected patients exhibiting clinically manifest and circumscribed macular retinal thickening; (ii) to compare the Z profile signal width values of a group of age similar normal subjects with those of the patients with macular retinal thickening; and (iii) to present the methodology underlying the Z profile signal width derivation. METHODS: Three patients with the following conditions were selected: widespread diabetic macular oedema; localised diabetic macular oedema; and macular hole. The patients were selected because they exhibited clinically manifest and circumscribed macular retinal thickening. Patients underwent fundus photography and a clinical examination which included fundus biomicroscopy. Fourteen age similar normal subjects were also assessed. The Heidelberg retina tomograph (HRT) was utilised to acquire seven topographic images of each macula. Z profile signal width data were analysed using custom software. Signal width was measured at 50% of the maximum intensity. RESULTS: For each patient with macular retinal thickening, Z profile signal width analysis (after normalisation to reduce the influence of variation in reflectance intensity between successive images) revealed a significant (p < 0.0001) localised increase of signal width which agreed with the HRT topographic analysis of retinal height, and also the clinical assessment of retinal thickness. The mean normalised Z profile signal width for the normal subjects (assessed over the whole image) ranged from 0.278 (SD 0.039) to 0.444 (0.063); these values compared with those obtained from patients in areas of macular retinal thickening of 0.761 (0.224) to 0.953 (0.194). Z profile signal width test-retest data for the patient with localised diabetic macular oedema were plus or minus 0.159 which compared with a mean signal width value of 0.761. CONCLUSION: The evidence of this study, based upon three selected patients with macular retinal thickening and 14 normal subjects, would suggest that Z profile signal width analysis offers a non-invasive, objective, topographic, and reproducible index of macular retinal thickening. Studies employing larger sample sizes are required to determine the true clinical worth of the technique.

Aged↗

PubMed1998

Clinical evaluation of scanning laser polarimetry: II. Polar profile shape analysis.

AIMS: To devise a method to describe and quantify the shape of polar profiles obtained with the scanning laser polarimeter and to compare this measurement with other polar profile measurements in a series of normal subjects and glaucoma patients. METHODS: Scanning laser polarimetry was performed on 54 normal subjects and 74 glaucoma patients. The retardation values obtained from one randomly chosen eye of each subject were analysed using our own methods, including the use of an algorithm to remove blood vessels from the polar profiles, an algorithm to standardise the glaucoma profiles to a normal database, and a further algorithm to evaluate the profile shape. The measurements of profile shape were compared with measurements of the absolute and standardised retinal nerve fibre layer thickness obtained with the scanning laser polarimeter. RESULTS: There was no significant difference between the mean retardation values for the normal and glaucomatous subjects in either hemiretina. However, standardisation of the glaucoma retardation values to a normal database produced significant differences at p < 1 x 10-8 in the mean retardation values for these two groups in both hemiretinas. Profile shape measurement analysis produced similar significant differences between the mean retardation values for the normal and glaucomatous subjects in both hemiretinas, although the degree of separation was greater following standardisation of the retardation values. CONCLUSION: The use of an algorithm to standardise an individual's retardation values in conjunction with a blood vessel removal algorithm enables an improvement in the ability of the scanning laser polarimeter to discriminate between normal and glaucomatous patients. The polar profile shape algorithm is independent of standardisation and significantly improves the discrimination between normal and glaucomatous patients, as well as providing additional information regarding the retinal nerve fibre layer.

Adult↗

PubMed1986

Velocity profiles in central airways with endotracheal intubation: a model study.

Steady inspiratory velocity profiles were measured at two flow rates in a 3:1 scale model of the human central airways in the presence of five modes of endotracheal intubation. The presence of an orifice or a short endotracheal tube had no significant effect on the velocity profiles distal to the carina. Long endotracheal tubes change the profiles in both main bronchi. A significant peak occurred in the frontal plane near the walls, and the maximum velocity in the airway was almost identical to the endotracheal tube center-line velocity. The flow impinging on the medial wall of the main bronchus was redirected up around the anterior and posterior walls yielding bipeak velocity profiles in the sagittal plane. A tube placed eccentrically in the trachea over the right main bronchus did not alter the velocity profiles in the left main bronchus, suggesting a redirection of flow over the carina into the left lung. An endobronchial tube at the mouth of the right main bronchus did change the shape of the velocity profiles in the left main bronchus. In the left upper lobar bronchus the presence of trachea intubation had no effect on the velocity profiles. However, in the right upper lobar bronchus, the long endotracheal tube flattened the velocity profiles from the strongly skewed ones seen in the absence of the endotracheal inserts. These results not only are relevant to distribution of ventilation and aerosol particle deposition, but also have strong implications in intrapulmonary gas mixing, especially when high-frequency low tidal-volume ventilation is involved.

Humans↗

PubMed1986

Velocity profiles of blood platelets and red blood cells flowing in arterioles of the rabbit mesentery.

Velocity profiles were determined in rabbit mesenteric arterioles (diameter 17-32 micron). A good spatial resolution was obtained by using the blood platelets as small and natural markers of flow, providing for the first time in vivo detailed, quantitative information about the shape of the velocity profiles in microvessels. In some experiments red blood cell velocity profiles were recorded as well. Easy detection of the cells of interest could be achieved by labelling them selectively with a fluorescent dye and visualizing them by intravital fluorescence video microscopy, using flashed illumination. Pairs of flashes were given with a short, preset time interval between both flashes, yielding in one TV picture two images of the same cell displaced over a certain distance for the given time interval. Velocity and mean radial position of cells, flowing within an optical section around the median plane of the vessel, were determined. The shape of the velocity profiles of platelets and red blood cells was similar. The profiles were flattened as compared to a parabola, both in systole and diastole. Vessel diameter did not change measurably during the cardiac cycle. As an index of the degree of blunting of the profiles, the ratio of the maximal and mean velocity of the profile was used, which is 2 for a parabola and 1 for complete plug flow. The index ranged from 1.39 to 1.54 (median 1.50), and increased with vessel diameter. Calculations showed that the blunting of the profiles cannot be explained by an influence of the finite depth of the optical section.

Animals↗

PubMed2006

Hereditary profiles of disorderly transcription?

BACKGROUND: Microscopic examination of living cells often reveals that cells from some cell strains appear to be in a permanent state of disarray without obvious reason. In all probability such a disorderly state affects cell functioning. The aim of this study was to establish whether a disorderly state could occur that adversely affects gene expression profiles and whether such a state might have biomedical consequences. To this end, the expression profiles of the 14 genes of the proteasome derived from the GEO SAGE database were utilized as a model system. RESULTS: By adopting the overall expression profile as the standard for normal expression, deviation in transcription was frequently observed. Each deviating tissue exhibited its own characteristic profile of over-expressed and under-expressed genes. Moreover such a specific deviating profile appeared to be epigenetic in origin and could be stably transmitted to a clonal derivative e.g. from a precancerous normal tissue to its tumor. A significantly greater degree of deviation was observed in the expression profiles from the tumor tissues. The changes in the expression of different genes display a network of interdependencies. Therefore our hypothesis is that deviating profiles reflect disorder in the localization of genes within the nucleus. The underlying cause(s) for these disorderly states remain obscure; it could be noise and/or deterministic chaos. Presence of mutational damage does not appear to be predominantly involved. CONCLUSION: As disturbances in expression profiles frequently occur and have biomedical consequences, its determination could prove of value in several fields of biomedical research.

Journal Article↗

PubMed2000

Prototypical profiles of the Brief Psychiatric Rating Scale.

Three prototypical profiles of the Brief Psychiatric Rating Scale (BPRS; Overall & Gorham, 1962) were isolated using a Q-type factor-analytic strategy with a sample of homeless men with mental illness (N=165). The 3 profiles--depressed, actively psychotic, and withdrawn--were used to study changes in BPRS profiles over time in a control group and a group that received assertive community treatment (ACT). Over2 time periods (inception to 12 months and 12-24 months), the 2 groups did not differ in terms of changes in profile shape, but they did differ in terms of changes in profile elevation. The ACT group evidenced a decrease in symptom severity during the last 12 months, whereas the control group showed an increase. Although changes in profile shape in both groups did occur, there was a significant tendency for the shape of the BPRS profiles to remain stable from the inception of the study to the 12-month assessment and from that time to the 24-month assessment. We describe the uses of these prototypical profiles and discuss the applicability of this analytical approach to other assessment instruments.

Adult↗