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Computer-animated comparison of self-perception with actual profiles of orthodontic and nonorthodontic subjects.

To determine if motivation for adult orthodontic treatment is influenced by self-perception, a computer morphing program was developed to animate discrete digitized photographs of facial profiles. It was hypothesized that orthodontic patients are less tolerant of variations in their profiles than nonorthodontic patients. Sixteen orthodontic and 14 nonorthodontic adult patients were presented with animated distortions of 5 features of the lower third of their own profiles. They were asked to identify the zone of acceptability in the changing profile and to indicate the single most pleasing distortion and their perceived and preferred profiles, for comparison with their actual profile. Although orthodontic subjects did not differ from nonorthodontic subjects in the zone of acceptability of their own profiles, they were less tolerant (smaller zone of acceptability) of variation in features of a standard control face. Orthodontic subjects, however, had a larger disparity between the most pleasing and at least one feature of their actual profile than did the nonorthodontic subjects. Orthodontic and nonorthodontic subjects were equally accurate in their ability to identify their own profile features. This unique method of measuring self-perception offers the clinician the advantage of providing a dynamic range rather than a single point of acceptable change to the patient. Moreover, this interactive computer program will enable patients to actively participate in treatment planning decisions by communicating preferences for variations in facial profile distortions.

Adult↗

Realizing the potential of practice pattern profiling.

In January 1992, the Physician Payment Review Commission held a conference to learn about the appropriateness of present uses of profiling of practice patterns, and to identify what will be required to realize the full potential of this technique in the future. The conference addressed the data needs of profiling, the development of valid and relevant profiles, the impact of profiles on medical practice, and controversies surrounding public access to profiling information and the uses to which profiling has been put. This paper, based in part on that conference, reviews the basic concepts that underlie profiling and describes the roles that profiling can play in quality improvement, assessment of provider performance, and utilization review. It uses case studies to illustrate the types of problems that have arisen in actual usage and discusses what will be required to resolve them. The final section describes the roles that profiling can play in achieving the goals of health care reform, and concludes with what is needed in data and infrastructure development to improve the quality and usefulness of profiling.

Data Collection↗

Limited cytomegalovirus-specific immunoglobulin M and immunoglobulin G profiles in heart transplant recipients.

Twenty heart transplant recipients were assayed serially with cytomegalovirus cultures and with Western blot techniques for development of anticytomegalovirus immunoglobulin M (IgM) and immunoglobulin G (IgG). Patients were followed up 3 to 29 months (mean, 15 months) after transplantation. All but three patients received a 5-week perioperative course of passive immunization with immune globulin. Of nine seronegative patients with seropositive grafts, positive cytomegalovirous cultures developed in all, secondary organ involvement (gastrointestinal or pneumonia) developed in four of nine. Four of nine patients produced limited IgM profiles, consisting of only one to three bands; six of the nine patients had atypical, restricted IgG profiles. Three of four patients in whom secondary organ invasion developed had limited IgM profiles, and all four had atypical IgG profiles. Four of five patients with primary infection without symptoms produced full IgM profiles. Delay of IgM production until a time coincident with or after evidence of viral shedding was documented in all patients with primary infection and secondary organ involvement. Among 11 seropositive patients, five received seropositive grafts and six seronegative grafts. Of the five patients with seropositive grafts, positive cultures (reinfection) developed in three; all three responded with full IgM profiles. However, secondary organ involvement developed in two of these three in spite of full IgM profiles. Symptomatic illness did not develop in any patient with a seronegative donor, even in the presence of positive cultures (reactivation). Persistence of IgM for up to 26 months was found in all patients with primary infection or reinfection. In heart transplant recipients, limited IgM and IgG profiles in primary infection may confer increased risk of secondary organ invasion whereas the early development of full IgM profiles may correlate with disease without symptoms. In seropositive patients, production of full IgM profiles may not protect from reinfection with secondary organ involvement if the organ donor is seropositive, a potential source of a new viral strain.

Antibodies, Viral↗

[Color Doppler echocardiography of the flow convergence region in vitro: effect of the orifice shape on proximal velocity profile].

The flow convergence method serves to determine flow across orifices (like valve leaks) by color Doppler. Both the PISA method (proximal isovelocity surface areas) and the PVP method (proximal velocity profile) were developed in vitro at circular orifice plates. Therefore, we studied the influence of a non-circular orifice shape on the color map of the flow convergence. Steady flow across orifices of the following shapes was imaged by color Doppler: Oval (6 x 2 mm), slit (12 x 1.5 mm), three-star (diameter 100, area 30 mm2), circular twin-orifice (two circular orifices diameter 2 mm at 10 mm distance from each other) and oval twin-orifice (two ovals 6 x 2 mm at 10 mm distance). As reference we imaged circular orifices with a similar opening area. The alias method was used to locate discrete velocities within the color map, and the proximal velocity profile along the flow center line was analyzed (mean of 24 subsequent images). The local velocity was plotted (y-axis) against its distance to the orifice (x-axis) providing proximal velocity profile curves. The more the orifice shape differed from circular, the more the proximal velocity profile was shifted downward: The profile proximal to the oval was not different from the reference profile proximal to the circular orifice. The profile proximal to the slit was considerably slowed, and proximal to the three-star was even slightly slower (local velocity -12 %, -23 % and -29 % at 14, 8 and 5 mm distance to the orifice). If the circular reference orifice corresponded to total flow across the twin-orifice, the proximal velocity profile of the latter was also shifted markedly downward (-20 %, -18 % and -23 % at 14, 8 and 5 mm distance to the circular twin-orifice). However, if the reference profile corresponded to flow across only one opening of the twin-orifice, the proximal velocity profile of the latter was shifted considerably upwards (+60 %, +71 % and +50 % at 14, 8, and 5 mm distance). Deviation of the orifice shape from circular leads to lower local velocities within the flow convergence; thus neglecting this orifice shape would result in underestimation of flow by the flow convergence method. However, presence of parallel neighboring flow increases the local velocities; neglecting this effect would lead to corresponding overestimation of flow.

Blood Flow Velocity↗

Comparison of non-human primate and human whole blood tissue gene expression profiles.

Gene expression profiling is an important tool in the development of medical countermeasures against chemical warfare agents (CWAs). Non-human primates (NHPs), specifically the rhesus macaque (Macaca mulatta), the cynomologus macaque (Macaca fascicularis), and the African green monkey (Chlorocebus aethiops), are vital models in the development of CWA prophylactics, therapeutics, and diagnostics. However, gene expression profiling of these NHPs is complicated by the fact their genomes are not completely sequenced, and that no commercially available oligonucleotide microarrays (genechips) exist. We, therefore, sought to determine whether gene expression profiling of NHPs could be performed using human genechips. Whole blood RNA was isolated from each species and used to generate genechip probes. Hybridization of the NHP samples to human genechips (Affymetrix Human U133 Plus 2.0) resulted in comparable numbers of transcripts detected compared with human samples. Statistical analysis revealed intraspecies reproducibility of genechip quality control metrics; interspecies comparison between NHPs and humans showed little significant difference in the quality and reproducibility of data generated using human genechips. Expression profiles of each species were compared using principal component analysis (PCA) and hierarchical clustering to determine the similarity of the expression profiles within and across the species. The cynomologus group showed the least intraspecies variability, and the human group showed the greatest intraspecies variability. Intraspecies comparison of the expression profiles identified probe sets that were reproducibly detected within each species. Each NHP species was found to be dissimilar to humans; the cynomologus group was the most dissimilar. Interspecies comparison of the expression profiles revealed probe sets that were reproducibly detected in all species examined. These results show that human genechips can be used for expression profiling of NHP samples and provide a foundation for the development of tools for comparing human and NHP gene expression profiles.

Animals↗

Rapid identification of bacteria from positive blood cultures by terminal restriction fragment length polymorphism profile analysis of the 16S rRNA gene.

Bacteremia results in significant morbidity and mortality, especially among patient populations that are immunocompromised. Broad-spectrum antibiotics are administered to patients suspected to have bloodstream infections that are awaiting diagnosis that depends on blood culture analysis. Significant delays in identification of pathogens can result, primarily due to the dependence on growth-based identification systems. To address these limitations, we took advantage of terminal restriction fragment (TRF) length polymorphisms (T-RFLP) due to 16S ribosomal DNA (rDNA) sequence diversity to rapidly identify bacterial pathogens directly from positive blood culture. TRF profiles for each organism were determined by sizing fragments from restriction digests of PCR products derived from two sets of 16S rDNA-specific fluorescent dye-labeled primers. In addition, we created a TRF profile database (TRFPD) with 5899 predicted TRF profiles from sequence information representing 2860 different bacterial species. TRF profiles were experimentally determined for 69 reference organisms and 32 clinical isolates and then compared against the predicted profiles in the TRFPD. The predictive value of the profiles was found to be accurate to the species level with most organisms tested. In addition, identification of 10 different genera was possible with profiles comprising two or three TRFs. Although it was possible to identify Enterobacteriaceae by using a profile of three TRFs, the similarity of the TRF profiles of these organisms makes differentiation of species less reliable with the current method. The ability to rapidly (i.e., within approximately 8 h) identify bacteria from blood cultures has potential for reducing unnecessary use of broad-spectrum antibiotics and promoting more timely prescription of appropriate antibiotics.

Bacteria↗

Analysis of the mutational effects of the COP/DET/FUS loci on genome expression profiles reveals their overlapping yet not identical roles in regulating Arabidopsis seedling development.

Microarray gene expression profiling was used to examine the role of pleiotropic COP/DET/FUS loci as well as other partially photomorphogenic loci during Arabidopsis seedling development and genome expression regulation. Four types of lethal, pleiotropic cop/det/fus mutants exhibit qualitatively similar gene expression profiles, yet each has specific differences. Mutations in COP1 and DET1 show the most similar genome expression profiles, while the mutations in the COP9 signalosome (CSN) and COP10 exhibit increasingly diverged genome expression profiles in both darkness and light. The genome expression profiles of the viable mutants of COP1 and DET1 in darkness mimic those of the physiological light-regulated genome expression profiles, whereas the genome expression profiles of representative lethal mutants belong to another clade and significantly diverge from the normal light control of genome expression. Instead, these lethal pleiotropic mutants show genome expression profiles similar to those from seedlings growth under high light intensity stress. Distinct lethal pleiotropic cop/det/fus mutants also result in distinct expression profiles in the small portion of genes examined and exhibit similar relatedness in both light and darkness. The partial cop/det/fus mutants affected expression of both light regulated and non-light regulated genes. Our results suggest that pleiotropic COP/DET/FUS loci control is largely overlapping but also has separable roles in plant development. The partially photomorphogenic loci regulate a subset of photomorphogenic responses as well as other non-light regulated processes.

Arabidopsis↗

Computerized profile perimetry in glaucoma.

The new profile testing mode of the COMPETER automatic perimeter was clinically tested and compared with careful manual profile perimetry on the Tübinger perimeter. Each of 110 patients with glaucomatous field defects, patients with suspected glaucoma, and normal subjects had one meridian tested. All of the 55 patients who showed an abnormal result on the manual profile also had abnormal findings on the automatic test. Two (4%) of the profiles labeled as normal on initial manual perimetry were identified by the automatic perimeter to be abnormal, and these defects were confirmed on repeated manual profile perimetry. The automatic perimetry gave five (9%) false-positive results in the 53 normal manual profiles, thus giving a specificity of 91%. In two of these cases, the automatic profile indicated defects in areas where the manual profile appeared normal, but there was abnormality in the manual kinetic perimetry in the affected area. The automatic profiles of the COMPETER automatic perimeter are accurate, sensitive, time-saving, and clinically useful.

Adolescent↗

Total RNA yield and microarray gene expression profiles from fine-needle aspiration biopsy and core-needle biopsy samples of breast carcinoma.

BACKGROUND: Gene expression profiling should be applicable to needle biopsy samples if microarray technology is to become practically useful for clinical research or management of breast carcinoma. This study compared gene expression profiles derived from fine-needle aspiration biopsy (FNAB) and from core needle biopsy (CBX). METHODS: Total RNA was extracted from single FNAB and CBX samples. Corresponding pairs of FNAB and CBX were analyzed for similarity of gene expression profiles using cDNA microarrays that contain 30721 human sequences. A subset of genes that distinguished CBX samples from FNAB samples was evaluated in a larger group of needle biopsy samples and in a published genomic database derived from 78 sporadic breast carcinomas with known clinical outcome. RESULTS: Sixty-eight patients with newly diagnosed breast carcinoma were included in the current study. Sixty-five patients underwent FNAB (17 had both FNAB and CBX) and 3 underwent CBX only. Extracted RNA was of suitable quality for hybridization in 46 (71%) FNABs and 15 (75%) CBXs. Total RNA yield in those samples was similar for single-pass FNAB (mean = 3.6 microg and median = 2.2 microg; n = 46) and CBX (mean = 2.8 microg and median = 2.0 microg; n = 15), with 1 microg or more of total RNA in all cases. Transcriptional profiling was performed successfully in all cases when it was attempted, in a total of 50 samples (38 FNABs and 12 CBXs), including matched FNAB and CBX samples from 10 patients. There were differences in gene expression profiles in 10 matched FNAB and CBX sample pairs. Genes that were expressed differently in CBX samples, compared with FNAB samples, were recognized as being predominantly from the endothelium, fibroblasts, myofibroblasts or smooth muscle, and histiocytes. Corresponding microscopic cell counts from FNABs demonstrated means of 80% tumor cells, 15% lymphocytes, and 5% stromal cells, whereas CBXs contained 50% tumor cells, 20% lymphocytes, and 30% stromal cells. Considering that CBXs are approximately six-fold richer in nonlymphoid stromal cells than FNABs and that CBXs differentially express a set of recognized stromal genes, the authors used these biopsies to define a transcriptional profile of breast carcinoma stroma. A set of 120 genes differentially expressed in CBXs was assessed independently in a published breast carcinoma genomic database to classify breast carcinomas based on stromal gene expression. Subgroups of tumors with low or high stromal signal were identified, but there was no correlation with the development of systemic metastases within 5 years. CONCLUSIONS: Both FNAB and CBX yield a similar quality and quantity of total RNA and are suitable for cDNA microarray analyses in approximately 70-75% of single-pass samples. Transcriptional profiles from FNAB and CBX of the same tumor generally are similar and are driven by the tumor cell population. The authors concluded that each technique has relative advantages. The FNABs provide transcriptional profiles that are a purer representation of the tumor cell population, whereas transcriptional profiles from CBXs include more representation from nonlymphoid stromal elements. Selection of the preferred needle biopsy sampling technique for genomic studies of breast carcinomas should depend on whether variable stromal gene expression is desirable in the samples.

Adult↗

Thymidine analogue reverse transcriptase inhibitors resistance mutations profiles and association to other nucleoside reverse transcriptase inhibitors resistance mutations observed in the context of virological failure.

During ZDV or d4T exposure, mutations at codons 41, 67, 70, 210, 215, and 219 can be selected and were named thymidine analogue mutations (TAMs). Some previous results suggested that different TAMs patterns could exist and that the kind of TAMs pattern could influence the virological response to some nucleoside reverse transcriptase inhibitors (NRTIs). In order to get more data about the relative prevalence of these patterns, their associations with other NRTI resistance mutations and the identification of the different stages observed during the acquisition of TAMs under treatment by NRTIs, we collected 1,098 RT sequences harbouring at least one TAM from patients failing to antiretroviral regimen. Sequences were stored in a database designed specifically to allow the retrieval of sequences that met specific criteria such as the occurrence and frequency of a particular mutation, the nature and frequency of the amino acid substitution at a given codon, and/or the rate of association between resistance mutations. Two pathways of TAMs can be identified: profile #1 (T215Y mutation linked) and profile # 2 (T215F mutation linked). The frequency of selection of profile # 1 is two times higher than profile # 2. The E44D/A + V118I complex, 69 insertions, and L74V mutation are associated to profile #1, whereas the Q151M complex and M184V mutation are associated to both profiles. As some NRTI resistance mutations were associated preferentially with profile #1, further studies are needed to explore if, the weaker efficacy observed on viruses harbouring this profile using some NRTIs, could be explained by the TAMs profile itself or the other associated NRTI resistance mutations.

Anti-HIV Agents↗

Methods for reconstructing phase sensitive slice profiles in magnetic resonance imaging.

The experimental determination of slice profiles excited by applying radiofrequency pulses in the presence of a gradient generally results in magnitude profiles. The conditions necessary to obtain a phase-sensitive picture of the profile of a slice are discussed. A distinction is made between the "excitation profile" (distribution of the transverse magnetization immediately after the RF pulse) and the "slice profile" (distribution after refocusing by gradient reversal and/or imperfect gradient switching). Methods are presented that allow one to obtain either the excitation profile or the slice profile. It is shown that phase encoding along the direction of the slice selection gradient provides a convenient protocol for obtaining the distribution of both the real and imaginary parts of the slice profile. The phase sensitive excitation profile can be obtained by frequency encoding. These methods were used to evaluate the performance of various shaped pulses.

Algorithms↗

Spatial velocity profile changes along the cord in normal human fetuses: can these affect Doppler measurements of venous umbilical blood flow?

OBJECTIVE: Several studies have assumed a parabolic velocity profile through the umbilical vein (UV) to derive the mean spatial velocity that is indispensable for flow rate calculations. However, the structure and arrangement of the umbilical cord suggest that velocity profiles may vary. The aim of this study was to evaluate UV spatial flow velocity profiles at different sites along the umbilical cord. METHODS: Ten singleton pregnancies with a gestational age between 26 and 34 weeks were included in the study. Ultrasound equipment with an inbuilt function for analysis of the spatial velocity profile along a line located in a fixed plane was used to obtain UV velocity profiles. Velocity profiles were obtained at the placental insertion and in a free intra-amniotic loop of the cord. Two-dimensional (2D) velocity distribution coefficients were evaluated as ratios between mean and maximum velocities along the investigated lines. RESULTS: 2D velocity distribution coefficients at the placental insertion (0.85 +/- 0.03) were significantly higher (P < 0.00001) than those obtained from a free loop of cord (0.76 +/- 0.03). Values indicated that velocity profiles are approximately flat at the placental insertion and become more parabolic moving downstream. Moreover, profiles become skewed in association with cord curvature and show peculiar biphasic shapes immediately downstream from the placenta. CONCLUSIONS: Flow velocity profiles in the UV are not perfectly parabolic and modify along the cord. These characteristics may affect the evaluation of UV blood flow rate.

Blood Flow Velocity↗

Can computerized risk profiles help patients improve their coronary risk? The results of the Coronary Health Assessment Study (CHAS).

BACKGROUND: The Coronary Health Assessment Study (CHAS) was developed to determine the feasibility of using patient-specific, multifactorial computerized coronary risk profiles as a clinical decision aid to support primary prevention of CHD. METHODS: Study participants included 253 community based physicians, randomized into profile and control groups, and 958 of their patients. The profile group physicians received coronary risk profiles for their patients within 10 working days after the baseline patient assessment providing early feedback. The control group received their profiles only if the patient was clinically reevaluated during a 3-month follow-up visit. Patients' coronary risk factors were evaluated at baseline and at follow-up. RESULTS: The profile group had a significantly higher (P < 0.05) ratio of high-risk/low-risk patients who returned for a follow-up visit compared to the control group (1.23 vs 0.77). The patients in the profile group also had significantly (P < 0.05) greater mean reductions in total cholesterol (-0.5 vs -0.1 mmol/L), LDL cholesterol (-0.4 vs 0.0 mmol/L), the total cholesterol/ HDL ratio (-0.6 vs -0.2), and the predicted 8-year coronary risk (-1.8 vs -0.3%). CONCLUSIONS: Computer-generated coronary risk profiles can be effective in assisting physicians to identify high-risk patients. Their use is also associated with significantly greater improvements in the serum lipid profiles and the overall coronary risk of these patients.

Adult↗

An experimental study of the esthetic effect of facial profiles.

In this study good-looking "male" and "female" as well as ugly facial profiles were shaped by 104 lay persons using an especially constructed device according to specific instructions. These profiles were photographed and subsequently evaluated using a series of parameters from soft tissue profile analyses. Although some significant mean value differences were found between the good-looking and ugly profile variants, they were not substantial. In contrast, markedly significant differences were revealed between the variances of all variables. In some instances the variance of the ugly profiles was more than 3 to 4 times higher than that of the good-looking profiles. These findings were convincingly confirmed when statistical distribution of the data was established and compared. This implies that perception of beauty is associated with regularity of facial features and is conveyed by measurement values which are located close to the mean. Ugliness is associated with extreme deviations from the latter in either direction. Apart from the facial proportions, the degree of convexity or concavity of facial profile and their sequence seem to be important for the esthetic effects. "Male" profiles in contrast to "female" profiles exhibited more conspicuous facial features such as pronounced convexity and concavity.

Adolescent↗

Perceived relative attractiveness of facial profiles with varying degrees of skeletal anomalies.

OBJECTIVE: The objective of this study was to answer the following questions: Are profiles of Class I patients perceived as more attractive than profiles of Class II or Class III patients in Germany today? How pronounced must a skeletal malocclusion be to be perceived as less attractive? Are there differences in perception between dentists and laypersons? MATERIAL AND METHOD: For the present study we examined seven patients with skeletal Class I, orthognathic maxillae and mandibles, and straight average faces (ideal biometric face as defined by A. M. Schwarz). Using the Onyx Ceph software, their profile lines were modified to reflect three different Class II profile variants and three different Class III profile variants. The 49 profiles thus obtained were assigned to two groups. Group 1 comprised the seven straight average faces and the first part of the retrognathic and prognathic profile variants. Group 2 comprised the same seven straight average faces and the remaining retrognathic and prognathic profile variants. Both groups of faces were scored by 130 laypersons and 126 dentists. RESULTS: Both groups of observers perceived the seven straight average faces similarly both in the first and second (subsequent) scoring rounds. The straight average face was perceived as most attractive by laypersons (mean, 5.48; 95% confidence interval (CI:) 5.33-5.60) and dentists (mean, 5.44; 95% CI, 5.28-5.50) alike, followed by the mildest variant of the retrognathic face (laypersons, mean, 4.85; 95% CI, 4.68-5.01; dentists, mean, 4.98; 95% CI, 4.81-5.10). Dentists differentiated more clearly by degree of skeletal malocclusion than did laypersons. Both groups alike perceived the extreme variant of the prognathic and retrognathic profile lines as the least attractive. Grouping the subjects by gender yielded only minor differences in perception. CONCLUSION: The straight average face is perceived as most attractive by representative German populations today. Dentists make clearer gradual distinctions in their perceptions than do laypersons.

Adult↗

Faecal elastase-1 and fat-soluble vitamin profiles in patients with cystic fibrosis in Western Norway.

BACKGROUND: Exocrine pancreatic insufficiency is a major clinical manifestation of cystic fibrosis (CF). Almost nine of ten patients develop signs and symptoms of maldigestion and malabsorption, which often deteriorates nutritional status and therefore worsens the prognosis. Human faecal elastase-1 (FE-1) has shown promising results to assess exocrine pancreatic insufficiency, and this test has been used at Haukeland University Hospital since 1996. AIM OF THE STUDY: To evaluate FE-1 values and fat-soluble vitamin profiles in patients with CF and to correlate exocrine pancreatic function as measured as FE-1 to fat-soluble vitamin profiles. Moreover, we wanted to assess if there are differences between fat-soluble vitamin profiles in patients with impaired versus patent exocrine pancreatic function, and thirdly, if fat-soluble vitamin deficiency at diagnosis is effectively treated by supplementation. METHODS: Consecutive analyses (N = 212) of fat-soluble vitamin profiles and 35 analyses of FE-1 were investigated in 35 patients with CF. In 17 out of 35 patients fat-soluble vitamin profiles were also assessed at diagnosis. Results Mean value of FE-1 for all CF patients was 256.9 microg/g faeces (median 24.1 microg/g faeces). CF patients considered to have maldigestion (N=24) showed a mean value of 19.9 microg/g faeces (median 18.7 microg/g faeces), those without pancreas affection had a mean value of 773.9 microg/g faeces (median 728.9 microg/g faeces, p < 0.01). There was no difference in fat-soluble vitamin profiles among patients with or without exocrine pancreatic insufficiency while on appropriate supplementation. Median value for vitamin E in patients with exocrine pancreatic insufficiency at diagnosis was low (3.6 mg/L). Supplementation of pancreatic enzymes and vitamins normalised profiles in this group at follow-up. There was no significant correlation between exocrine pancreatic function as measured as FE-1 and fat-soluble vitamin profiles, neither in patients with impaired nor in those with patent pancreatic function. CONCLUSIONS: Severe degree of exocrine pancreatic insufficiency is common in patients with cystic fibrosis. There was no correlation of faecal elastase-1 levels to fat-soluble vitamin status. Fat-soluble vitamins (A, D, E) given in appropriate dosages combined with pancreatic enzymes ensured normal profiles in our patients with CF and malabsorption. Officially recommended supplementation of vitamin A and D in Norway during infancy and childhood may explain why so few patients had vitamin deficiencies at diagnosis.

Adolescent↗

Antinuclear antibody (ANA) and ANA profile tests in children with autoimmune disorders: a retrospective study.

The study objective was to determine the clinical value of positive antinuclear antibody (ANA) and ANA profile tests in children with autoimmune disorders. A retrospective chart review was carried out of all patients under 18 years of age with a positive ANA test (HEp-2 cell substrate, titre > or =1:40) and ANA profile (ELISA) referred to the paediatric rheumatology service at the authors' institution between 1992 and 1996. Of 245 children with a positive ANA test, 134 (55%) had an autoimmune disease, including juvenile rheumatoid arthritis (n = 49), systemic lupus erythematosus (SLE) (n = 40) and others (n = 45). The remaining 111 patients did not have identifiable autoimmune diseases. Patients with autoimmune disorders had significantly higher ANA titres of > or = 1:160 (chi2 = 16, P<0.0001). In addition, of the 245 patients with a positive ANA test, 86 had an ANA profile performed; this was positive in 32 and negative in 54. All 32 patients with a positive ANA profile (100%) had an autoimmune disorder, compared to 22 (41%) of 54 with a negative ANA profile who had autoimmune disorders. Of 22 SLE patients with a positive ANA profile, 16 (73%) had positive anti-dsDNA and 15 (68%) had positive anti-Sm and positive anti-RNP. A positive ANA profile correlated strongly with an ANA titre > or = 1:640 (chi2 = 5.7 , P<0.02). The study demonstrated that only 55% of children with a positive ANA test had a definitive diagnosis of autoimmune disorder. These children tend to have higher ANA titres of > or =1:160. However, a positive ANA profile was strongly correlated with an ANA titre > or =1:640 and highly indicative of an autoimmune disorder (100%). We suggest that in order to reduce cost, an ANA profile should not be performed on all patients with positive ANA, but reserved for those with an ANA titre of > or =1:640 and/or those with a high clinical index of suspicion for autoimmune disorder, especially SLE.

Antibodies, Antinuclear↗

The application of segment axial density profiles to a human body inertia model.

The intention of this study was to construct segment density profiles and compare segment inertias calculated when uniform densities and profile densities are used in a mathematical model. Axial densities from computerized tomography (CT) slices for the body segments of a sample of Chinese females (Zheng et al., Proceedings of the Beijing Asian Games Scientific Congress, 1990) were used to form profiles which could be employed in body segment models. Polynomials based on proportion of segment length were fitted to the reported mean slice densities. These profiles were then used with five widely divergent samples (n = 10); young adult females, young adult males, infants, male children and elderly adults. The mathematical model used is based on an assumption that all segments can be represented by stacked elliptic cylinders. The results show that when the profile densities were substituted for average cadaver densities the increase in the estimated total body mass was less than 0.85%. For the individual segments, use of the profile rather than average density increased the average segment mass estimate by up to 2.7%. The centres of mass and the principal moments were affected by the variations in density along the axis as well as the magnitudes, by up to 0.54 and 3.8%, respectively. Although the effects of using the profiles appear to be small the differences for individual samples, segments and parameters ranged up to 22.5%. It is not possible to decide if average or profile densities produce more accurate estimates of inertia, but the profile allows for axial variation in density and is therefore recommended.

Adolescent↗