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PubMedDate not supplied

The role of the family therapist in health risk reduction.

To increase significantly the amount and duration of behavior change in health education risk reduction programs, a multi-dimensional approach is needed. The family system in which each individual functions has a unique impact on an individual's probability of change. The authors propose that risk reduction programs include family therapists as primary change agents and suggest that multiple family therapy is the most effective strategy for reducing long-term change. This model may be applied and adapted to meet the characteristics and needs of most health education risk reduction programs. Given the prevalence of heart disease and cancer, the problems of bringing about risk reduction behavior change have been paramount in the health care community. Attrition rates and recidivism, however, have plagued risk reduction programs. It is proposed that by including family therapists in these programs, personal and family issues may be hindering and/or sabotaging attempted behavior change could be resolved, thus facilitating greater success.

Family↗
PubMed1989

[Comparison of two dimensional and three dimensional CBF measurements in stroke patients].

The purpose of this study is to compare the detectability of the reduction in cerebral blood flow (CBF) using the two versus the three dimensional technique of CBF measurement. Both techniques were simultaneously carried out 85 times on 52 stroke patients. In the two dimensional technique, CBF was measured by the Xe-133 inhalation method and the value was calculated by the initial slope index. In the three dimensional technique, CBF was measured by single photon emission CT with Xe-133 inhalation method. CBF reduction was studied in the middle cerebral artery (MCA) territory on a CBF map in both techniques. Additionally, mean CBF was also calculated for the same territory. On the CBF map, the CBF reduction was shown in 25 of 85 measurements with the two dimensional technique and in 41 of 85 with the three dimensional technique. In comparing the imagings of both techniques, the CBF reduction seen extensively along the cortical surface and in the entire MCA territory with the three dimensional technique was also detected with the two dimensional technique. However, focal CBF reduction observed at the cortical surface and in the deep cerebral tissue with the three dimensional technique was not detected with the two dimensional technique. In order to evaluate both techniques quantitatively, we calculated the ratio of the mean CBF difference between the MCA territories of both hemispheres to mean CBF in the non-affected MCA territory. This ratio represented the asymmetry index. Firstly, the relationship between asymmetry index and the imaging of CBF reduction on the CBF map was studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed2006

The effect of necrotic lesion size and rotational degree on the stress reduction in transtrochanteric rotational osteotomy for femoral head osteonecrosis--a three-dimensional finite-element simulation.

BACKGROUND: The prospect for success in the efficacy of osteotomy for precollapse stage of femoral head osteonecrosis depends on the ability to predict reliably the stress changes derived from specific osteotomies. A three-dimensional finite-element analysis was thus designed to compute necrotic femoral head stress changes with different extent of necrocrosis that accompany anterior or posterior rotational osteotomies. METHOD: Computed tomography images of a standard composite femur were used to create the three-dimensional finite-element intact femur model. Based on the intact model, 27 models simulating three different levels of necrotic region together with nine different rotational osteotomies were created. The von Mises stress distributions of each model were analyzed and compared for a loading condition simulating single-legged stance. FINDINGS: (1) The stress reduction in anterior rotational osteotomy is more effective as compared to that of the posterior rotational osteotomy for various necrotic lesion sizes. (2) Von Mises stress on the necrotic zone decreased with increasing rotational angle. The decreasing rate was higher for the femoral head with a narrow lesion. (3) Femoral head with a wider necrotic lesion had a higher risk for developing collapse due to high local stress on the surface of necrotic region; whereas the necrotic region tended to expand in size instead of collapse for femoral head with a narrow lesion due to high local stress on the interface between necrotic region and healthy bone. INTERPRETATION: Transtrochanteric rotational osteotomy is a technically demanding procedure and associated with high complication risks, a more scrupulous planning including the finite-element analysis should be considered before doing surgery in clinical subjects.

Femur Head↗
PubMed1999

Timing regulation in a network reduced from voltage-gated equations to a one-dimensional map.

We discuss a method by which the dynamics of a network of neurons, coupled by mutual inhibition, can be reduced to a one-dimensional map. This network consists of a pair of neurons, one of which is an endogenous burster, and the other excitable but not bursting in the absence of phasic input. The latter cell has more than one slow process. The reduction uses the standard separation of slow/fast processes; it also uses information about how the dynamics on the slow manifold evolve after a finite amount of slow time. From this reduction we obtain a one-dimensional map dependent on the parameters of the original biophysical equations. In some parameter regimes, one can deduce that the original equations have solutions in which the active phase of the originally excitable cell is constant from burst to burst, while in other parameter regimes it is not. The existence or absence of this kind of regulation corresponds to qualitatively different dynamics in the one-dimensional map. The computations associated with the reduction and the analysis of the dynamics includes the use of coordinates that parameterize by time along trajectories, and "singular Poincaré maps" that combine information about flows along a slow manifold with information about jumps between branches of the slow manifold.

Animals↗
PubMed2005

Effect of pravastatin on malondialdehyde-modified low-density lipoprotein levels and coronary plaque regression as determined by three-dimensional intravascular ultrasound.

We hypothesized that a reduction in atherogenic malondialdehyde-modified low-density lipoprotein (MDA-LDL) levels, which may antagonize the action of atheroprotective high-density lipoprotein cholesterol, leads to coronary plaque regression. This study investigated the effects of pravastatin on the serum levels of MDA-LDL and coronary atherosclerosis. In a 6-month prospective study, 75 patients with stable coronary artery disease were randomly assigned to a pravastatin-treatment group (n = 52) or a control group (n = 23). Volumetric analyses were performed in matched coronary artery segments by 3-dimensional intravascular ultrasound. Pravastatin therapy for 6 months resulted in a decrease in coronary plaque volume (14.4%, p <0.0001) and a corresponding reduction in serum MDA-LDL levels (12.7%, p = 0.0001). In the pravastatin treatment group, the percentage of change in plaque volume correlated with changes in the MDA-LDL and high-density lipoprotein cholesterol levels (r = 0.52 and -0.55, respectively, p <0.0001) but not with the changes in any other lipid levels. Multivariate regression analysis revealed that a reduced MDA-LDL level is an independent predictor of plaque regression, as was an increase in high-density lipoprotein cholesterol. In conclusion, these results suggest that the reduction in the MDA-LDL levels induced by pravastatin may serve as a novel marker of coronary atherosclerosis regression.

Anticholesteremic Agents↗
PubMed1995

Abdominal aortic aneurysms: findings on three-dimensional display of helical CT data.

Excellent vascular opacification, reduction in misregistration artifacts, and the option of reconstructing overlapping scans from which three-dimensional (3D) models of the abdominal vessels may be rendered are among the benefits of helical CT [1-4]. The purpose of this essay is to illustrate the findings of 3D rendering of helical CT data in patients with abdominal aortic aneurysms.

Aortic Aneurysm, Abdominal↗
PubMed2003

Computed tomographic assessment of fractures of the posterior wall of the acetabulum after operative treatment.

BACKGROUND: The purpose of this study was to evaluate the results after operative treatment of fractures of the posterior wall of the acetabulum in relationship to the quality of the fracture reduction as assessed by postoperative two-dimensional computed tomography. METHODS: The functional results for sixty-seven patients who had open reduction and internal fixation of an unstable fracture of the posterior wall of the acetabulum and the findings of two-dimensional computed tomography performed postoperatively were analyzed. Sixty-one patients were followed for a mean of four years after the injury, and the remaining six patients who had poor early results necessitating reconstructive surgery were followed for less than two years. All patients were evaluated preoperatively and postoperatively with use of three standard plain radiographs (one anteroposterior and two Judet 45 degrees oblique pelvic radiographs) and a two-dimensional computed tomography scan. The functional outcome for the patients was evaluated with use of a modification of the clinical grading system described by Letournel and Judet. The radiographs were graded according to the criteria described by Matta. The two-dimensional computed tomography scans were used to determine fracture gap and offset measurements. RESULTS: The clinical outcome was graded as excellent in thirty-one patients (46%), very good in twenty (30%), good in eight (12%), and poor in eight (12%). The final radiographic results were graded as excellent in fifty-three hips (79%), good in four (6%), fair in three (5%), and poor in seven (10%). There was a strong association between clinical outcome and final radiographic grade. Fracture reductions were graded as anatomic in sixty-five and imperfect in two, as determined with use of plain radiography. However, postoperative computed tomography revealed an incongruency (offset) of >2 mm in eleven hips and fracture gaps of > or = 2 mm in fifty-two. Fracture gaps of > or = 10 mm in any dimension or a total gap area of > or = 35 mm(2) were associated with a poor result. The main risk factors for a poor result were a residual fracture gap width of > or = 10 mm and osteonecrosis of the femoral head. CONCLUSIONS: The degree of residual fracture displacement is detected more accurately on postoperative computed tomography scans than on plain radiographs. The accuracy of surgical reduction as assessed on postoperative computed tomography is highly predictive of the clinical outcome. LEVEL OF EVIDENCE: Therapeutic study, Level III-2 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.

Acetabulum↗
PubMed1992

Two-dimensional mapping of N-glycosidically linked asialo-oligosaccharides from glycoproteins as reductively pyridylaminated derivatives using dual separation modes of high-performance capillary electrophoresis.

N-Glycosidically linked oligosaccharides were released from glycoproteins by digestion with trypsin followed by hydrazinolysis and subsequently re-N-acetylated and reductively pyridylaminated. Derivatives of sialic acid-containing oligosaccharides were further desialylated with neuraminidase. The final derivatives of asialo-oligosaccharides were analyzed by capillary zone electrophoresis in two carriers, an acidic phosphate buffer and an alkaline borate buffer. The former carrier allowed direct zone electrophoresis as cationic immonium ions, accordingly size-dependent separation, whereas the latter realized indirect electrophoresis as anionic borate complexes, i.e., separation based on the structural variation in outermost monosaccharide residues. Two-dimensional plots of relative mobilities of the derivatives in these dual separation modes to reductively pyridylaminated glucose provided a good tool for identification of oligosaccharides.

Algorithms↗
PubMed1981

Quantitative two dimensional echocardiography during bicycle exercise in normal subjects.

A quantitative two dimensional echocardiographic study was conducted in 10 normal subjects performing bicycle exercise in a supine position. Standardized two dimensional echocardiographic short axis and apical views of the left ventricle were analyzed to derive left ventricular sectional areas and length. Over a range of exercise heart rates from 108 to 152 beats/min, satisfactory two dimensional echocardiographic views and measurements were obtained for quantitative assessment of sectional and global left ventricular function. Variability of left ventricular short axis area measurements ranged from 2.9 to 8.3 percent. Left ventricular volume reconstruction employed a simplified formula (volume = 5/6 area X length) with a single papillary muscle level short axis area and left ventricular length. Changes in left ventricular function from rest to exercise quantitated by two dimensional echocardiography indicated a significant reduction in end-systolic volume (from 28.1 +/- 5.6 to 20.8 +/- 4.3 cc/m2, p less than 0.001) and increased left ventricular ejection fraction (from 63.4 +/- 6.3 to 72.1 +/- 5.7 percent, p less than 0.001). The change in end-diastolic volume was not significant. It is concluded that standardized two dimensional echocardiographic study during supine bicycle exercise in normal subjects provides good reproducibility of measurement of sectional and global left ventricular function. Quantitative two dimensional echocardiographic exercise study of global as well as segmental left ventricular performance in patients may be feasible using standardized procedure and analysis.

Adolescent↗
PubMed1995

Direct stereological estimation of three-dimensional connectivity in rat vertebrae: effect of estrogen, etidronate and risedronate following ovariectomy.

Newly developed unbiased stereological methods were employed to investigate the effects of estrogen deficiency on the three-dimensional connectivity of vertebral cancellous bone from ovariectomized (OVX) rats. The effects of two classes of antiresorptive agents, estrogen and bisphosphonates, on changes in connectivity in this animal model were also evaluated. Female rats were either sham-operated (sham-op) or surgically OVX at 90 days of age. OVX rats were administered either vehicle, estrogen (10 micrograms/kg 17-beta estradiol, 5 days/week subcutaneously [SC], etidronate disodium (5 mg/kg SC) or risedronate (5 micrograms/kg SC). The bisphosphonates were administered daily for 1 week followed by 3 weeks with no treatment. Treatment duration was 360 days. Systematic random sections, 30-microns thick, were prepared from methylmethacrylate-embedded decalcified second lumbar vertebrae. Total trabecular number and connectivity density were estimated using the ConnEulor principle. Vertebral cancellous bone volume was estimated on undecalcified sections from the first lumbar vertebrae. Connectivity density and cancellous bone volume were significantly reduced (approximately 25% and 40%, respectively) in the OVX group compared with the sham-op group. Estrogen treatment essentially maintained connectivity and cancellous bone volume at the level of the sham-op rats. Connectivity density and total trabecular number were significantly increased in the etidronate- and risedronate-treated rats compared with both the sham-op and OVX rats. These data demonstrate that reduction in the three-dimensional connectivity of vertebral cancellous bone is a long-term consequence of ovariectomy in the rat. This reduction in connectivity can be effectively prevented by the administration of antiresorptive agents such as estrogen, etidronate and risedronate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

A novel method for visualizing functional connectivity using principal component analysis.

Functional connectivity is a useful measure of voxel-wise functional magnetic resonance imaging signals that allows for the identification of functionally related brain areas and distributed networks. However, the high dimensionality of functional connectivity makes it difficult to visualize. In most studies, a small percentage of the total functional connectivity is visualized through diagrams that are constructed using individual seed voxels. In the present study describes a new method for visualizing most of the functional connectivity through a single diagram. This method does not rely on seed voxels, but rather employs a reduction of the high-dimensionality of the functional connectivity via a projection onto a three-dimensional color space using principal components analysis. With this new method, most of the information contained in a functional connectivity matrix can be represented through a single color-coded functional connectivity map, thereby facilitating a greater visual appreciation of functional connectivity.

Brain↗
PubMed1993

Kinematics of jaw movements during chewing at different frequencies.

The three-dimensional jaw movement trajectory and its velocity profile were investigated to provide information regarding the motor control of chewing. This was done on a cycle-by-cycle basis across three voluntarily guided chewing frequencies to test the lack of invariance at the velocity level and the evidence for a cost function. The data revealed that an increase in chewing frequencies resulted in a significant reduction of the three-dimensional path, being significantly higher in opening than closing. The ratio of peak speed/three-dimensional distance, a kinematic index of stiffness, increased with increase in chewing frequency; higher stiffness being associated with faster chewing, the stiffness being significantly higher in opening than in closing. The ratio of peak velocity to mean velocity decreased as a function of increase in chewing frequency only at the highest frequency and this decrease again was different in opening than in closing. The results demonstrated that the velocity profile of chewing movements, like that of speech movements, lacked invariance. Rather than minimizing one cost function, the system used an efficient trade-off between time, space and effort, based on the objective of movements.

Adult↗
PubMed2001

A population density approach that facilitates large-scale modeling of neural networks: extension to slow inhibitory synapses.

A previously developed method for efficiently simulating complex networks of integrate-and-fire neurons was specialized to the case in which the neurons have fast unitary postsynaptic conductances. However, inhibitory synaptic conductances are often slower than excitatory ones for cortical neurons, and this difference can have a profound effect on network dynamics that cannot be captured with neurons that have only fast synapses. We thus extend the model to include slow inhibitory synapses. In this model, neurons are grouped into large populations of similar neurons. For each population, we calculate the evolution of a probability density function (PDF), which describes the distribution of neurons over state-space. The population firing rate is given by the flux of probability across the threshold voltage for firing an action potential. In the case of fast synaptic conductances, the PDF was one-dimensional, as the state of a neuron was completely determined by its transmembrane voltage. An exact extension to slow inhibitory synapses increases the dimension of the PDF to two or three, as the state of a neuron now includes the state of its inhibitory synaptic conductance. However, by assuming that the expected value of a neuron's inhibitory conductance is independent of its voltage, we derive a reduction to a one-dimensional PDF and avoid increasing the computational complexity of the problem. We demonstrate that although this assumption is not strictly valid, the results of the reduced model are surprisingly accurate.

Animals↗
PubMed1988

The role of three-dimensional computed tomography in the management of maxillofacial trauma.

Open reduction and internal fixation of facial fractures demand a detailed understanding of the three-dimensional pattern of injury. This is difficult if not impossible to obtain with present radiographic methods. The purpose of this study was to define the role of three-dimensional computerized tomography (3DCT) in surgical management of facial fractures. The two-part investigation: 1) compared the diagnostic accuracy of 3DCT with conventional CT and plain film studies; and 2) examined the clinical usefulness of 3DCT to surgeons. Twenty-four acute trauma patients suspected of having facial fractures were examined radiographically with analysis of every facial bone and specific facial regions. Particular attention was directed to the course of the fracture lines and the number, size, and displacement of fracture fragments. The surgeons were then asked to conceptualize the reported and the personally observed radiographic information and document their impressions on preprinted diagrams of the facial skeleton. They also completed questionnaires designed to indicate whether patient management would be influenced by the 3DCT. The radiographic findings were correlated with intraoperative observations. The 3DCT provided superior definition of fracture lines (especially horizontal) and the extent of comminution was better appreciated. This additional information improved the surgeons' ability to plan placement of interfragmentary wires and/or plates. Surgeons were also able to more accurately predict those patients requiring immediate bone grafting. Large, life-size 3D images of the facial skeleton made intraoperative conceptualization of the injury pattern easier. The accuracy of the 3DCT images corroborated the intraoperative findings in all cases. The following conclusions are offered: 1) The diagnosis of most mandibular fractures can be made equally well with conventional and 3DCT techniques. 2) Improved diagnosis of fracture lines and the specific patterns of comminution in midface fractures is made possible with 3DCT. 3) If open reduction and internal fixation is the mode of treatment, 3DCT is desirable because the added information makes preoperative planning more accurate and thereby facilitates surgical intervention.

Facial Injuries↗
PubMed1993

Keratin synthesis in SV40-transformed human keratinocytes after transient supertransfection with Harvey murine sarcoma viral DNA.

A transformed cell line (HE-IS) was established by transient supertransfection of a SV40-transformed human epidermal cell culture (HE-SL) (R. T. Su and Y.-C. Chang, 1989, Exp. Cell Res. 180, 117-133) with a recombinant plasmid containing an entire Harvey murine sarcoma virus DNA. HE-IS cells showed morphological alterations and less stringent growth requirements in a defined medium. A variant line (HE-TC), selected later from the HE-IS cells after a prolonged maintenance in serum-containing Dulbecco's minimal essential medium (DMEM), was found to be able to grow in either defined or serum-containing medium. Neither HE-IS nor HE-TC cells were able to form colonies in soft agar or induce tumors in athymic mice when inoculated subcutaneously. When grown in defined medium, all transformed cells (HE-SL, HE-IS, HE-TC) revealed a similar keratin pattern as analyzed by two-dimensional gel electrophoresis. However, significant reduction of keratins (notably K5) was detected in HE-TC cells maintained in serum-containing DMEM. The keratin pattern appeared to be regulated by the growth environment. Because of their nontumorigenic characteristics and defined growth properties, these transformed keratinocytes are likely to provide a suitable model system for examining the regulation of cytoskeleton protein synthesis.

Cell Division↗
PubMed2006

Significant reduction of normal tissue dose by proton radiotherapy compared with three-dimensional conformal or intensity-modulated radiation therapy in Stage I or Stage III non-small-cell lung cancer.

PURPOSE: To compare dose-volume histograms (DVH) in patients with non-small-cell lung cancer (NSCLC) treated by photon or proton radiotherapy. METHODS AND MATERIALS: Dose-volume histograms were compared between photon, including three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and proton plans at doses of 66 Gy, 87.5 Gy in Stage I (n=10) and 60-63 Gy, and 74 Gy in Stage III (n=15). RESULTS: For Stage I, the mean total lung V5, V10, and V20 were 31.8%, 24.6%, and 15.8%, respectively, for photon 3D-CRT with 66 Gy, whereas they were 13.4%, 12.3%, and 10.9%, respectively, with proton with dose escalation to 87.5 cobalt Gray equivalents (CGE) (p=0.002). For Stage III, the mean total lung V5, V10, and V20 were 54.1%, 46.9%, and 34.8%, respectively, for photon 3D-CRT with 63 Gy, whereas they were 39.7%, 36.6%, and 31.6%, respectively, for proton with dose escalation to 74 CGE (p=0.002). In all cases, the doses to lung, spinal cord, heart, esophagus, and integral dose were lower with proton therapy even compared with IMRT. CONCLUSIONS: Proton treatment appears to reduce dose to normal tissues significantly, even with dose escalation, compared with standard-dose photon therapy, either 3D-CRT or IMRT.

Carcinoma, Non-Small-Cell Lung↗
PubMed1994

Three-dimensional time-of-flight MR angiography with variable TE (VARIETE) for fat signal reduction.

Uniform fat saturation over a large region of interest remains a problem in time-of-flight (TOF) magnetic resonance angiography applications. We demonstrate that a variable echo time with an opposed phase value at low spatial slice select frequencies can effectively reduce most of the fat signal in an otherwise standard three-dimensional TOF acquisition. We evaluated this method at 1.5 T using a short TE = 5.3 ms and a long TE = 6.75 ms for different values of the slice encoding gradient (i.e., different kz values). Shorter echo time (TE = 5.3 msec) was used at higher spatial slice select frequencies, but all echoes have the same gradient structures. By keeping the number of slice encoding steps with longer echoes to a minimum, field inhomogeneity effects on flow compensation remained small. A magnetization transfer saturation pulse was used to suppress signal of brain parenchyma. Overall, highly uniform and selective fat signal reduction was obtained while maintaining superior flow compensation in all volunteer studies.

Adipose Tissue↗
PubMed2004

Proteome changes in ovarian epithelial cells derived from women with BRCA1 mutations and family histories of cancer.

Malignant transformation of the ovarian surface epithelium (OSE) accounts for most ovarian carcinoma. Detection of preneoplastic changes in the OSE leading to overt malignancy is important in prevention and management of ovarian cancer. We identified OSE proteins with altered expression derived from women with a family history (FH) of ovarian and/or breast cancer and mutations in the BRCA1 tumor suppressor gene. Proteins from SV-40-transformed FH-OSE cell lines and control OSE lines derived from women without such histories (non-family history) were separated by two-dimensional PAGE. Gels were analyzed, a protein data base was created, and proteins were characterized according to their molecular weight, isoelectric point, and relative abundance. Mass spectrometry was performed on tryptic protein digests, and data bases were searched for known proteins with the same theoretical tryptic peptide masses. Several proteins showed altered expression in the FH-OSE cells. Beta-tubulin and to a lesser extent ubiquitin carboxyl-terminal hydrolase and glyoxalase 1 appeared to be up-regulated. In contrast, proteins suppressed in FH lines include the 27-kDa heat shock protein, translationally controlled tumor protein, and several proteins associated with actin modification such as actin prepeptide, F-actin capping protein alpha subunit, and cofilin. Sequencing of several cofilin gel spots revealed phosphorylation of serine 3, a post-translational modification associated with decreased actin binding and cytoskeletal reorganization. Two-dimensional Western blots probed with cofilin antibody showed multiple protein spots with isoelectric points of 6-9 pH units. Blots of one-dimensional gels showed a significant reduction in cofilin expression in three FH lines when compared with three non-family history lines (p < or = 0.05). Identification of these and other OSE proteins may be useful in detecting changes suggestive of increased risk of developing preneoplastic disease and defining the possible role(s) of the BRCA1 gene in regulation of OSE cell function.

Actin Depolymerizing Factors↗