SEARCH · PubMed Health

Results for “shared variables”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources

PubMed1997

Studies of polymorphic DNA fingerprinting and lipid pattern of Mycobacterium tuberculosis patient isolates in Japan.

Strain differentiation by DNA restriction fragment length polymorphism (RFLP) has been used mainly for the epidemiological purpose of Mycobacterium tuberculosis infection. In this study, we tried to connect the molecular and phenotypic characteristics of M. tuberculosis patient isolates by comparing the DNA fingerprints obtained by RFLP using IS6110 and lipid patterns using two-dimensional thin-layer chromatography (2-D TLC) with silica gel, since M. tuberculosis has a lipid-rich cell envelope which contributes to the virulence and immunomodulatory properties. We found that 66 isolates of M. tuberculosis from tuberculosis patients showed that the occurrence of IS6110 varied from 1 to 24 copies. The IS6110 patterns were highly variable among isolates. Fifty different RFLP patterns were observed, and 12 RFLP patterns were shared by two or more strains. By computerized analysis of the RFLP patterns of M. tuberculosis patient isolates, we found that 95% of the isolates fell into seven clusters, from A to G, with at least two isolates in each (> 30% similarity). Among the cellular lipids, the phospholipid composition did not differ by strain, whereas the glycolipid pattern differed markedly. Especially, the relative concentration of cord factor and sulfolipid, both of which were known as virulent factors, varied by strain. The fingerprints of some strains showed an association between the DNA and glycolipid patterns, even though some of the same DNA fingerprint strains showed differences in lipid patterns. Among the patient isolates, M. tuberculosis strain 249 possessed a specific glycolipid with 2-O-methyl-L-rhamnose and L-rhamnose, which is rarely found in other strains. This glycolipid showed serological activity against the sera of tuberculosis patients, even if the reactivity was not as strong as trehalose dimycolate. It also showed the inhibition of phagosome-lysosome fusion in macrophages, suggesting involvement with virulence. These results suggest that RFLP analysis using IS6110 is useful for clustering the human isolates of M. tuberculosis, however, for further strain differentiation on virulence, a lipid analysis provides more information.

Antibodies, Bacterial↗

PubMed2004

Children's beliefs about the importance of gender in transgression situations.

OBJECTIVE: In previous research, several variables are shown to have an impact on children's perception of gender. The aim of this study was to examine the relation between discipline methods and the child's beliefs about the importance of gender in transgression situations. METHODS: In this study, variables such as type of siblings, socioeconomic status, child's sex, parental values and shared responsibility are controlled for. Two hundred and five 8-year-old children in Sweden were interviewed about discipline methods in five transgression situations and their parents were asked to fill in a battery of questions. RESULTS: The results show that harsher discipline methods, such as behaviour modification, physical restraint and physical punishment, relate to stronger beliefs about the importance of gender in transgression situations.

Attitude↗

PubMed1985

A F(ab')2 fragment blocking study of the HLA-B14 antigen.

The HLA-B14 antigen exists in two serologically distinct forms termed Bw64 and Bw65. These two B14 subgroups were studied using the ability of F(ab')2 fragments from HLA-B14 and Bw6 antisera to block the binding of cytotoxic HLA antibodies directed towards the same or an adjacent antigenic site. The findings suggest that the B14 antigen consists of several antigenic determinants some of which are spatially distinct and others which are closely associated. A "common" determinant possessed by both B14 subtypes is proposed which is separate from a Bw64 (or Bw65) site. Additional determinants that B14 shares with B8, B18 and B38/B39 appear to be distinct from the Bw64/Bw65 site, variably associated with the B14 "common" determinant but closely adjoining the Bw6 antigen.

Binding, Competitive↗

PubMed1984

Amygdaloid kindling in Papio cynocephalus and subsequent recurrent spontaneous seizures.

Three baboons, Papio cynocephalus, (two photosensitive and one nonphotosensitive) were subjected to amygdaloid kindling. Electroclinical profile of seizure development-developed seizure compares very favourably to that described in photosensitive baboons, Papio papio, with rapid seizure progression and ultimate emergence of Stage 5 bisymmetrical and bisynchronous generalized convulsive state. In addition, one baboon developed spontaneous recurrent seizures which were identical to the kindled Stage 5 seizure. It is concluded that the state of exceptional seizure susceptibility observed in Papio papio is shared by Papio cynocephalus, although photosensitivity and kindled generalized convulsion appear to be independent variables.

Amygdala↗

PubMed2001

Sensitization studies in chemically intolerant individuals: implications for individual difference research.

Chemical intolerance (CI) is an individual difference trait in which persons report feeling ill in multiple physiological systems from low levels of a wide range of chemically unrelated environmental substances. This paper discusses the neural sensitization model for progressive host amplification of polysymptomatic responses elicited by chemical exposures following an initiating event. The sensitization model accommodates hypotheses for initiating and eliciting CI in human populations that involve both environmental chemicals and physical or psychological stressors. Recent studies in this laboratory have demonstrated sensitization in individuals with CI over repeated sessions for dependent variables such as electroencephalographic (EEG) activity and diastolic blood pressure. Psychological distress variables alone do not explain these findings. Individuals with CI and/or vulnerability to sensitization share specific characteristics, for example, female gender, certain genetic background (offspring of alcohol-preferring parents), and personal preference for high sugar/ carbohydrate intake. Overall, the data suggest that the 15-30% of the general population who report heightened CI are highly sensitizable. Sensitizability may serve an adaptive, sentinel function in threatening environments with poor signal-to-noise ratios. However, as sensitization gradually shifts operating set points of physiological systems out of the normal range in response to allostatic load, this process may contribute to the development of chronic, polysymptomatic health conditions such as multiple chemical sensitivity and/or fibromyalgia. Individual response specificity and stereotypy rather than toxicant properties may determine which types of central, autonomic, and/or peripheral nervous system dysfunctions manifest at subclinical and clinical levels.

Age of Onset↗

PubMed2005

Seronegative spondyloarthropathies: to lump or split?

The advent of novel biological therapies for the treatment of rheumatic disease has renewed interest in the seronegative spondyloarthropathies (SpAs). International efforts are redefining disease classification and measures of disease activity, outcome, metrology, and imaging. However, opinion is divided between those who propose that the SpA group represents the same disease with variable expression (the "lumpers") and those who consider these to be separate diseases with shared clinical features (the "splitters"). This review presents the evidence for both approaches.

Arthritis, Psoriatic↗

PubMed1995

FokI DNA repeats in the genome of Vicia faba: species specificity, structure, redundancy modulation, and nuclear organization.

Tandemly repeated DNA sequences about 60 bp in length, which may be isolated by digestion with FokI restriction endonuclease, were studied by means of molecular and cytological hybridization in Vicia faba and other Vicia species. The results obtained can be summarized as follows: (i) FokI repeats are almost species specific to V. faba, since they hybridize to a minimum extent to genomic DNA of only two out of five related species; (ii) these tandemly repeated elements display variability in structure even within one and the same array, where different repeats may share not more than 71% homology; (iii) their redundancy in the genome of V. faba is remarkably high and varies largely between land races (copy numbers per haploid, 1C, genome range from 21.51 x 10(6) to 5.39 x 10(6)); (iv) FokI repeats are clustered in differing amounts in each subtelocentric pair of the chromosome complement and are missing or present in a nondetectable amount in the submetacentric pair; (vi) chromosome regions that bear these repeats associate closely to varying degrees in interphase nuclei. These results are discussed in relation to possible functional roles that tandemly repeated DNA sequences such as the FokI elements might play.

Base Sequence↗

PubMed2003

Mouse model for hereditary hemorrhagic telangiectasia has a generalized vascular abnormality.

BACKGROUND: Mutations in endoglin or activin like kinase-1, both involved in the endothelial transforming growth factor-beta signaling pathway, cause the autosomal dominant bleeding disorder hereditary hemorrhagic telangiectasia. We and others have reported mouse models for this disease that share the characteristic phenotype of dilated vessels and sporadic hemorrhage. The reasons for the variable phenotype in hereditary hemorrhagic telangiectasia are not understood. METHODS AND RESULTS: After a detailed immunohistochemical analysis of 129/Ola mice, which are heterozygous for a targeted deletion in the endoglin gene, we observed intrinsic abnormalities in the vascular walls throughout the cutaneous vasculature. Postcapillary venules were dilated, and up to 70% of the vascular wall had no smooth muscle cells. The supporting layers of collagens and elastin were irregular, with thin areas, adding to the fragility of these vessels. A variable hemorrhagic phenotype was observed in which local bleeding is associated not only with fragile vessels but also with regions of inflammation. CONCLUSIONS: These findings have relevance to our understanding of the molecular basis of vascular integrity in a wide range of diseases.

Animals↗

PubMed2006

The importance of participation in support groups for women with ovarian cancer.

PURPOSE/OBJECTIVES: To explore the experience of participation in support groups for women recently diagnosed with ovarian cancer. RESEARCH APPROACH: Exploratory, qualitative. SETTING: Oncology department in a hospital in western Sweden. PARTICIPANTS: 10 Swedish women, aged 42-76, who recently had been diagnosed with ovarian cancer and had participated in support groups. METHODOLOGIC APPROACH: Data were collected by semistructured interviews and analyzed using grounded theory. MAIN RESEARCH VARIABLES: Ovarian cancer, support group experience. FINDINGS: Three categories emerged from the data analysis: sharing experiences and emotions, exchanging informational support, and exchanging emotional support. The core category was the experience of being in the same boat. Trust, openness, and willingness to create space for each other were experienced. CONCLUSIONS: Support groups offer an opportunity to share experiences and emotions as well as exchange information. They are also a possible source of emotional support and therefore can contribute to quality of life of patients with ovarian cancer. INTERPRETATION: Knowing that others had similar symptoms and reactions, and that those experiences are normal, was very important for support group participants. Nurses can reduce patients' fears and uncertainties by confirming normality. Oncology nurses need to be aware that cancer support groups offer a unique opportunity to interact with others in a similar situation. Participation in support groups can be an important source of emotional and informational support for patients. The support program in this study may be used as a model when planning for extended emotional and informational support.

Adult↗

PubMed2001

Genetic variation of the nucleocapsid genes of waterfowl parvovirus.

Duck parvovirus (DPV) and Goose parvovirus (GPV) isolated from infected waterfowls with Derzsy's disease in the year 1999 were identified by polymerase chain reaction and sequencing. The nucleotide sequences of their viral capsid proteins (VPs) show that they share 77% similarity at the DNA, and 84.6% at the protein level. The most variable region between DPV and GPV resides in the N-terminal of VP2 before the initiation codon of VP3 with 35% (19/54) amino acids divergence. Viral capsid protein sequences diverge 4.1 to 4.4% among 1990-99 isolated strains. Variant amino acids cluster in the common regions of VP3 at residues 203-266 and 482-534 which overlaps with the regions proposed to expose on the outer surfaces of parvoviral particles, implying that selective pressure from host immune system might play a part. These data provide useful information for antigenic epitope prediction. This study also reveal the presence of conserved strain-specific residues in VPs and these residues seldom vary among different viral isolates, suggesting that they might be functionally important and worth further investigation.

Amino Acid Sequence↗

PubMedDate not supplied

Risk factors for human T cell lymphotropic virus type I among injecting drug users in northeast Brazil: possibly greater efficiency of male to female transmission.

It was observed in the city of Salvador, State of Bahia, the highest seroprevalence of human T cell lymphotropic virus type 1 (HTLV-I) infection in Brazil as demonstrated by national wide blood bank surveys. In this paper, we report results of an investigation of drug use and sexual behavior associated with HTLV-I infection among male and female injecting drug users (IDUs) in Salvador. A cross sectional study was conducted in the Historical District of Salvador from 1994-1996 (Projeto Brasil-Salvador) and 216 asymptomatic IDUs were selected using the snowball contact technique. Blood samples were collected for serological assays. Sera were screened for human immunodeficiency virus (HIV-1/2) and HTLV-I/II antibodies by ELISA and confirmed by Western blot. The overall prevalence of HTLV-I/II was 35.2% (76/216). The seroprevalence of HTLV-I, HTLV-II and HIV-I was for males 22%, 11.3% and 44.1% and for females 46.2%, 10.3% and 74.4% respectively. HTLV-I was identified in 72.4% of HTLV positive IDUs. Variables which were significantly associated with HTLV-I infection among males included needle sharing practices, duration of injecting drug use, HIV-I seropositivity and syphilis. Among women, duration of injecting drug use and syphilis were strongly associated with HTLV-I infection. Multivariate analysis did not change the direction of these associations. Sexual intercourse might play a more important role in HTLV-I infection among women than in men.

Adolescent↗

PubMed1990

Glycemic index of foods in individual subjects.

We studied 12 subjects with diabetes to determine how well the glycemic index (GI) predicted the ranking of glycemic responses of different foods in individuals. All subjects ate three mixed meals (bread, rice, or spaghetti with GIs of 100, 79, and 61, respectively) four times in a randomized complete block design. The mean glycemic response areas of the different meals ranked according to the predicted GI in every individual. The observed mean +/- SD GI values of the meals were significantly different from each other (bread 100 +/- 7, rice 75 +/- 9, spaghetti 54 +/- 9), with no significant difference in response between subjects. It is concluded that individuals share common mean GI values for different foods. Within confidence limits determined by the variability of glycemic responses, the number of repeated tests conducted, and the expected GI difference, the GI can be used to predict the ranking of the mean glycemic responses of mixed meals taken by individuals.

Adult↗

PubMedDate not supplied

Metastatic melanoma: the spectrum of ultrastructural morphology.

The fine structure of 26 metastatic melanomas, including 13 pigmented and 13 amelanotic tumors, as studied to define ultrastructural criteria for diagnosis. Several important features in addition to melanosome granules were identified. Dendritic cytoplasmic processes were seen in 25 of the 26 cases, cell clusters formed by concentric aggregates of several cells and their processes were present in 18, and microvilli were found on cell surfaces in all cases. The cytoplasm was complex, containing numerous mitochondria, Golgi systems, endoplasmic reticulum, nonspecific filaments, and microtubules. Nuclear morphology was variable. Basement membranes and cell junctions including desmosomes were often encountered, and some melanomas shared features with Schwann cells, including complex membrane interdigitations. All tumors contained melanosomes, although the classic forms were frequently difficult to identify and abnormal variant forms often predominated. Knowledge of the variant melanosome morphology and an understanding of the other fine structural features of malignant melanocytes can help identify those cases that lack classic premelanosome granules.

Adolescent↗

PubMed1999

The adoption of provider-based rural health clinics by rural hospitals: a study of market and institutional forces.

OBJECTIVE: To examine the response of rural hospitals to various market and organizational signals by determining the factors that influence whether or not they establish a provider-based rural health clinic (RHC) (a joint Medicare/Medicaid program). DATA SOURCES/STUDY SETTING: Several secondary sources for 1989-1995: the AHA Annual Survey, the PPS Minimum Data Set and a list of RHCs from HCFA, the Area Resource File, and professional associations. The analysis includes all general medical/surgical rural hospitals operating in the United States during the study period. STUDY DESIGN: A longitudinal design and pooled cross-sectional data were used, with the rural hospital as the unit of analysis. Key variables were examined as sets and include measures of competitive pressures (e.g., hospital market share), physician resources, nurse practitioner/physician assistant (NP/PA) practice regulation, hospital performance pressures (e.g., operating margin), innovativeness, and institutional pressure (i.e., the cumulative force of adoption). PRINCIPAL FINDINGS: Adoption of provider-based RHCs by rural hospitals appears to be motivated less as an adaptive response to observable economic or internal organizational signals than as a reaction to bandwagon pressures. CONCLUSIONS: Rural hospitals with limited resources may resort to imitating others because of uncertainty or a limited ability to fully evaluate strategic activities. This can result in actions or behaviors that are not consistent with policy objectives and the perceived need for policy changes. Such activity in turn could have a negative effect on some providers and some rural residents.

Community Health Centers↗

PubMed2000

The evolution of hospitalist programs.

In just a few years, hospitalist programs have evolved to a third generation, affording key participants an opportunity to reduce inpatient healthcare costs. Because the method of inpatient payment determines the economic winners and losers in the program, the key participants will benefit from the implementation of a program that includes shared incentives. Even though reduced payments for inpatient services might be offset by reduced variable costs for hospitals and increased office revenues for primary care physicians, a hospitalist program is more likely to achieve sustained success if it is structured so that financial rewards are distributed fairly among the participants.

Contract Services↗

PubMed2000

SIRS and MODS: what is their relevance to the science and practice of intensive care?

SIRS (the Systemic Inflammatory Response Syndrome) and MODS (the Multiple Organ Dysfunction Syndrome) are not diseases or syndromes, but concepts. Common to both is the notion that the morbidity of critical illness arises indirectly, from the response of the host to an acute, life-threatening challenge to systemic homeostasis. The biology of that response is complex and variable, yet implicit in our evolving understanding of systemic inflammation is the possibility that shared biologic mechanisms may permit the development of effective therapy for a wide variety of disorders that appear superficially heterogeneous. The challenge lies in characterizing common pathologic processes or diseases. The four criteria that define SIRS are non-specific measures of physiologic severity, rather than distinctive manifestations of a disease process. Perhaps the use of the systemic correlates of the cardinal manifestations of inflammation developed by Galen and Celsus would provide a more satisfactory clinical characterization of the clinical disorder. However, the complexity of the biologic processes involved suggest that a clinical syndrome of systemic inflammation is of no more use to the clinician than a clinical syndrome of cancer. As the functio laesa of systemic inflammation, organ dysfunction is more appropriately viewed as an undesireable outcome of systemic inflammation, a complication to be prevented, rather than a disease to be treated. As concepts, SIRS and MODS provide a useful intellectual framework for investigation, but the clinician must treat diseases, no acronyms. The challenge will be to characterize these disease.

Animals↗

PubMed2003

Population pharmacokinetics of ciprofloxacin in pediatric patients.

The objective of this study was to characterize ciprofloxacin population pharmacokinetics in pediatric patients. A total of 150 pediatric patients (including 28 patients with cystic fibrosis [CF], ages 0.27-16.9 years) received ciprofloxacin by the oral and/or intravenous routes. Population pharmacokinetic analyses were performed with NONMEN software. Exponential error models were used to describe the interindividual variance in pharmacokinetic parameters, and the residual error model included both proportional and additive components. Based on principles of allometry, the patient's body weight was used as a covariate, along with appropriate allometric exponents, in the construction of the base model. Model building was accomplished by a stepwise forward inclusion procedure, and the final model was evaluated by multiple techniques, including bootstrap, leverage analysis, and cross-validation. With body weight included in the model (two compartments with first-order absorption), ciprofloxacin clearance was influenced by age, and the absorption rate constant was altered in CF patients. The final model is summarized as follows: CL(L/h) = 30.3 x (WT/70)0.75 x (1 + 0.045 [AGE-2.5]), VC(L) = 56.7 x (WT/70)1.0, VP(L) = 89.8 x (WT/70)1.0, Q(L/h) = 37.5 x (WT/70)0.75, Ka (1/h) = 1.27 x (1 + [-0.611 x CF]), absorption lag time = 0.35 hours, and bioavailability fraction = 61.1%, where WT and AGE are the patient's body weight (kg) and age (years), respectively, and the variable CF equals 1 for CF patients and 0 for non-CF patients. The interpatient variability in pharmacokinetic parameters (percentage coefficient of variation [%CV]) ranged from 22.5% to 49.8%. The residual variabilities (%CV) for the oral and intravenous data were 40% and 27%, respectively. The shared additive residual variance component was small (SD = 0.04 mg/L). Model evaluation by the different methods indicated that the final model was robust and parameter estimates were precise. A small difference (< 6%) was noted when the patient's age was not used in dose calculation. Therefore, in routine clinical use, for pediatric patients older than 3 months, ciprofloxacin dose may be calculated solely based on body weight.

Administration, Oral↗

PubMed1992

T cell activation-inducing epitopes of the house dust mite allergen Der p I. Proliferation and lymphokine production patterns by Der p I-specific CD4+ T cell clones.

Cloned human CD4+ T cell lines specific for the house dust mite Dermatophagoides pteronyssinus were used to map minimal T cell activation-inducing epitopes on the Group I allergen in D. pteronyssinus extracts (Der p I) molecule. Most of these Der p I-specific T cell clones expressed different TCR V alpha and V beta gene products. Using recombinant deletion proteins, three T cell epitopes were identified on the Der p I molecule; p45-67 and p117-143 were recognized by HLA-DR7-restricted T cells, whereas p94-104 was recognized in the context of HLA-DR2, DRw11 (DR5), and -DR8 molecules. This degenerate class II MHC restriction appears to be due to shared Phe and Asp residues at positions 67 and 70, respectively, in the third variable domain of the HLA-DR beta chain. All three T cell epitopes induced Th2-like cytokine production profiles by the Der p I-specific T cell clones, which were characterized by the production of very high levels of IL-4 and IL-5, as compared with those secreted by tetanus toxin-specific T cell clones derived from the same patients, but no or low amounts of IL-2 and IFN-gamma. This Th2-like production profile was, however, not an intrinsic property of the Der p I-specific T cells, but was dependent upon their mode of activation. Stimulation with Con A also induced very low or no measurable levels of IL-2 and IFN-gamma, whereas activation with TPA and the calcium ionophore A23187 resulted in the production of high levels of IL-4, IL-5, IL-2, and IFN-gamma. These results indicate that Der p I-specific T cell clones are not defective in their capacity to produce high levels of Th1 cytokines.

Allergens↗