Biomedical subjects

C Phillips

Publications and source records attributed to C Phillips.

At least 163 records · Page 9Linked to original sources

PubMed1994

Changes in vertical tooth position and face height related to long term anterior repositioning splint therapy.

This study evaluates whether extended full-time wear of a partial coverage mandibular anterior repositioning splint (MORA) causes intrusion of posterior teeth and determines the effect on jaw position. Sixty-four patients from two private orthodontic practices were studied using cephalometric radiographs to measure vertical change in position of the anterior and posterior teeth and the mandible. The splint wear time ranged from a minimum of one half year to a maximum of 4.8 years, with a mean of 1.33 years. No significant change was recorded in the distance from the mandibular molar to the mandibular plane. On average, the maxillary incisor and maxillary molar extruded about 1 mm, while the mandibular molar was unchanged and the mandibular incisor intruded about 0.6 mm. Posterior face height increased an average of 1.6 mm, and anterior face height increased an average of 2.7 mms. In 20% of the patients, intrusion of the mandibular molars of 1 mm or more occurred. In 41%, extrusion of the maxillary incisors of 1 mm or more was noted. Intrusion of the upper molars or extrusion of the lower incisors occurred in only 5% of the patients. The data indicates that only a very small proportion of patients having long term splint therapy using the MORA have clinically significant molar intrusion. Change in mandibular position was expressed in a vertical increase in posterior and anterior face height. Only very small changes occurred in antero-posterior position.

Adolescent↗

PubMed1994

MDS Cognitive Performance Scale.

BACKGROUND: Chronic cognitive impairment is a major problem in U.S. nursing homes, yet traditional assessment systems in most facilities included only limited information on cognitive status. Following the Congressional mandate in the Omnibus Reconciliation Act of 1987 (OBRA '87), U.S. nursing homes now complete the Minimum Data Set (MDS), a standardized, comprehensive assessment of each resident's functional, medical, psychosocial, and cognitive status. We designed a Cognitive Performance Scale (CPS) that uses MDS data to assign residents into easily understood cognitive performance categories. METHODS: Information was drawn from three data sets, including two multistate data sets constructed for the Health Care Financing Administration. The prevalence and reliability of the MDS cognitive performance variables were established when assessed by trained nursing personnel. Five selected MDS items were combined to create the single, functionally meaningful seven-category hierarchical Cognitive Performance Scale. RESULTS: The CPS scale corresponded closely with scores generated by the Mini-Mental State Examination and the Test for Severe Impairment, nursing judgments of disorientation, and neurological diagnoses of Alzheimer's disease and other dementias. CONCLUSIONS: The new CPS provides a functional view of cognitive performance, using readily available MDS data. It should prove useful to clinicians and investigators using the MDS to determine a resident's cognitive assets.

Activities of Daily Living↗

PubMed1994

Insulin syringe disposal practices of pediatric patients with insulin-dependent diabetes mellitus.

Pediatric patients with insulin-dependent diabetes mellitus were surveyed over a 5-month period to determine disposal practices of insulin syringes. Eighty-nine (79.5%) of 112 patients surveyed responded. Thirty-three percent of the responders disposed of syringes in accordance with recommendations of the local health department and the American Diabetes Association, while the remaining patients did not. Fifty-two percent of the patients rendered the syringes useless before disposal. The study revealed a need to educate and inform patients on the proper procedures that should be followed when disposing of syringes in the home.

Adolescent↗

PubMed1994

The burden and outcomes associated with dehydration among US elderly, 1991.

OBJECTIVES: Dehydration has been underappreciated as a cause of hospitalization and increased hospital-associated mortality in older people. This study used national data to analyze the burden and outcomes following hospitalizations with dehydration in the elderly. METHODS: Data from 1991 Medicare files were used to calculate rates of hospitalization with dehydration, to examine demographic characteristics and concomitant diagnoses associated with dehydration, and to analyze the contribution of dehydration to mortality. RESULTS: In 1991, 6.7% (731,695) of Medicare hospitalizations had dehydration listed as one of the five reported diagnoses, a rate of 236.2/10,000 elderly Medicare beneficiaries. In 1991, Medicare reimbursed over $446 million for hospitalizations with dehydration as the principal diagnosis. Older people, men, and Blacks had elevated risks for hospitalization with dehydration. Acute infections, such as pneumonia and urinary tract infections, were frequent concomitant diagnoses. About 50% of elderly Medicare beneficiaries hospitalized with dehydration died within a year of admission. CONCLUSIONS: Hospitalization of elderly people with dehydration is a serious and costly medical problem. Attention should be focused on understanding predisposing factors and devising strategies for prevention.

Age Factors↗

PubMed1994

Research utilization in critical care: an exemplar.

The authors describe the process and outcome of implementing a research-based pain management protocol in four adult critical care units at a large, Midwestern tertiary care center. The project was initiated and directed by members of the divisional research committee. Strategies used to change practice included determining if pain management was a problem via quality assessment monitors, surveying nurses regarding their knowledge and attitude toward pain management, educating staff members about the research base for the practice change, using change champions in each unit, and developing a core group of nurses in each unit to facilitate the change. Outcomes of this research utilization project include a 41% decline in the number of patients in pain, a 44% decline in pain intensity, and improvement in nurses knowledge about pain.

Clinical Nursing Research↗

PubMed1994

Analysis of condylar position changes: a test of validity of posteroanterior cephalometric and 20-degree lateral cephalometric techniques enhanced by digital subtraction.

This preclinical study was designed to evaluate 20-degree lateral cephalometric and posteroanterior cephalometric techniques with digital subtraction enhancement for their ability to detect 1-, 2-, and 3-mm shifts in condylar position in two of three planes of space (horizontal or transverse and vertical). The model used was a dry human skull with a complete mandible mounted on a microscopic stage with positioning accuracy to 0.1 mm in x, y, and z planes. Analysis of variance showed no significant difference from expected values in the transverse plane (posteroanterior cephalogram only). There were significant differences in the sagittal plane (20-degree lateral cephalogram only) for the 2- and 3-mm shifts (P < .001). There were no significant differences among expected values in the vertical plane for individual increments or for increment comparisons. The magnitude of standard deviations and of the absolute value of differences indicates markedly increased variability for both techniques as compared to tomograms produced with cephalostat repositioning. The authors conclude that even with precise repositioning and digital subtraction enhancement, cephalometric radiographs are inadequate for clinical monitoring of condylar position.

Analysis of Variance↗

PubMed1994

Stability following superior repositioning of the maxilla by Le Fort I osteotomy: five-year follow-up.

Changes in dental and skeletal relationships were evaluated 5 years postsurgically in 49 patients whose maxilla had been superiorly repositioned by a Le Fort I osteotomy. All of the patients had at least 2 mm of intrusion at the maxillary incisor and molar; none had a mandibular ramus osteotomy or other osteotomy except genioplasty. Only 6.5% had 2 mm or greater of net vertical change in skeletal or dental landmarks at 1 year postsurgery. From 1 to 5 years postsurgery, minimal changes in skeletal and dental landmarks occurred in the majority of the patients, but approximately 25% of the patients showed 2 mm or more of downward movement of the maxilla and/or eruption of maxillary teeth, leading to downward-backward rotation of the mandible. Only one patient had more than 1 mm of open bite on long-term follow-up. An increase in overbite, resulting from incisor eruption, was noted in 14%, and an increase in overjet occurred in 12% as the mandible rotated. It appears that modest long-term skeletal and dental changes occur in some surgically treated long-face patients. The likelihood of long-term change was not related to the age of the patient, stability during the first postsurgical year, or segmentation of the maxilla at surgery.

Adolescent↗

PubMed1993

Preliminary crystallographic study of 6-phosphogluconate dehydrogenase from Trypanosoma brucei.

We have obtained well-ordered single crystals of 6-phosphogluconate dehydrogenase, an enzyme of the oxidative branch of the pentose phosphate pathway, from Trypanosoma brucei. The crystals are trigonal rhombs with unit cell dimensions a = b = 135.1 A, c = 116.7 A and belong to one of the enantiomorphic pair of space groups P3(1)21/P3(2)21. X-ray diffraction to better than 2.8 A has been recorded using a rotating anode CuK alpha source. Elucidation of the three-dimensional structure of the T. brucei enzyme will, by indicating structural differences from the known sheep enzyme structure, aid the design of mutants to probe the active site. Knowledge of the structure will also assist in assessing the potential use of rationally designed compounds to inhibit this enzyme specifically.

Animals↗

PubMed1993

Referral adherence in an inner city breast and cervical cancer screening program.

BACKGROUND: Early detection and immediate follow-up treatment for cancer of the breast and cervix can reduce morbidity and mortality. This report describes adherence to follow-up appointments for suspected breast and cervical malignancies in a population of low-income black women who participated in a community-based nurse-managed screening program. METHODS: Components of the program that were part of the intervention included the following: a consistent referral mechanism augmented by a computerized tickler system; education of women about the importance of follow-up; and active nurse assistance in the follow-up process. Referral for follow-up of suspected malignancies or for other questionable findings was made to the public sector hospital clinics (86%) or to other providers of the women's choice (14%). RESULTS: Follow-up rates for suspected malignancies of the breast were high (92%) in this population of women, sometimes described as less likely to adhere to recommendations for continued care. In contrast, adherence rates for gynecologic conditions were lower (70%). CONCLUSIONS: This screening program and follow-up system has relevance to systems that serve similar groups of low-income women.

Adult↗

PubMed1993

X-ray crystallographic structure of a papain-leupeptin complex.

The three-dimensional structure of the papain-leupeptin complex has been determined by X-ray crystallography to a resolution of 2.1 A (overall R-factor = 19.8%). The structure indicates that: (i) leupeptin contacts the S subsites of the papain active site and not the S' subsites; (ii) the 'carbonyl' carbon atom of the inhibitor is covalently bound by the Cys-25 sulphur atom of papain and is tetrahedrally coordinated; (iii) the 'carbonyl' oxygen atom of the inhibitor faces the oxyanion hole and makes hydrogen bond contacts with Gln-19 and Cys-25.

Amino Acid Sequence↗

PubMed1993

Cross-linking of surface IgM, but not surface IgD receptors, by soluble monoclonal antibodies primes murine B cells to secrete immunoglobulin in response to lymphokines.

We have previously reported the development of a two-step culture system in which soluble anti-mu monoclonal antibodies prime small resting murine B cells to secrete immunoglobulin (Ig) in response to restimulation with a mixture of interleukin-4 (IL-4) and IL-5. Here we have extended these studies to investigate the effects of engaging surface IgD (sIgD). We find that, unlike anti-mu, three different anti-delta monoclonal antibodies did not prime B cells to secrete Ig. In addition, these anti-delta antibodies inhibited anti-mu-stimulated priming for Ig secretion, while enhancing DNA synthesis in response to anti-mu. Furthermore, anti-delta antibodies still inhibited anti-mu-induced priming when added 24-48 h after anti-mu. These results therefore suggest that triggering of sIgD on B cells induces a dominant inhibitory signal which is not necessarily dependent upon co-ligation of sIgM and sIgD receptors. In addition, these findings raise the possibility that ligating sIgM or sIgD receptors on mature B cells in the absence of T cell help, may produce different downstream effects.

Animals↗

PubMed1993

Characterization of T-cell clones generated from skin of patients with psoriasis.

BACKGROUND: The infiltrating cells in psoriasis include a subpopulation of autoreactive T cells. OBJECTIVE: The aim of this study was to further characterize skin-infiltrating T lymphocytes in patients with psoriasis. METHODS: Forty-five T-cell clones were generated from skin biopsy specimens from two patients. RESULTS: Phenotypic studies on 25 of 45 clones revealed that 19 (76%) of the clones were CD4+, 5 (20%) were CD8+, and 1 (4%) clone was CD4- and CD8-. Twenty-three clones were stained for identification of T-cell receptors. Twenty-two clones expressed alpha/beta T-cell receptors and one clone (CD4-/CD8-) expressed no T-cell receptor. Nineteen clones (42%) were autoreactive with no restriction to class I or class II HLA antigens. By contrast, proliferation of two of the seven clones was inhibited by class I monoclonal antibody, whereas proliferation of four of seven clones was inhibited by class II monoclonal antibody. CONCLUSION: These data suggest that skin-infiltrating lymphocytes in patients with psoriasis may recognize HLA-associated molecules, perhaps the peptide of the HLA groove. The recognition of the peptide is presumably inhibited when monoclonal antibody is bound to the HLA molecule.

CD4 Antigens↗

PubMed1993

In vivo correlation of Doppler waveform analysis with arterial input impedance parameters.

Previous studies have confirmed that Doppler waveform analysis (DWA) offers a valid reflection of changes in peripheral vascular resistance. However, the ability of the pulsatility index (PI), a parameter of DWA, to reflect the dynamic components of the circulation, as assessed by arterial input parameters, remains uncertain. In addition, the state of the central circulation is considered an important factor influencing the accuracy of this technique. This study evaluated the ability of the aortic PI to reflect alterations of input impedance in a chronically instrumented lamb model that was subjected to pharmacologic alteration of the circulation. Pressure, volumetric flow and continuous-wave Doppler frequency shift measurements were recorded from the infrarenal abdominal aorta. The parameters of input impedance, peripheral vascular resistance (Zpr), characteristic impedance (Zo) and reflection coefficient (Rc), were determined and then correlated with changes in the aortic PI. Initially, perturbations of the circulatory state were created with a vasodilator, hydralazine (HY) and a vasoconstrictor, phenylephrine (PE). During a second set of experiments, the effect of the reflex heart rate (HR) responses on the PI was evaluated. This was accomplished by inhibiting reflex HR responses to these vasoactive agents with either trimethophan (TM) or atropine methyl bromide (AMB). In response to HY and HY with TM, significant decreases in the PI and impedance parameters occurred. Administration of PE and PE with AMB resulted in significant increases in PI and each of the impedance parameters. HY and PE induced changes in PI correlated significantly with changes in volumetric flow (r = 0.82, 0.80; p < 0.001), mean arterial blood pressure (r = 0.64, 0.70; p < 0.001) and Zpr (r = 0.77, 0.80; p < 0.001), but not with Zo (r = 0.34, 0.36) and Rc (r = 0.26, 0.31). However, when reflex HR responses were inhibited during the administration of the vasoactive agents, HY with TM and PE with AMB, induced changes in PI correlated significantly with Zo (r = 0.93, 0.89; p < 0.001) and Rc (r = 0.84, 0.83; p < 0.001), and the correlation with mean arterial pressure (r = 0.78, 0.87; p < 0.05) and Zpr (r = 0.92, 0.91; p < 0.05) was significantly greater. These findings indicate that the PI accurately assesses pharmacologically induced changes in the downstream arterial input impedance. The accuracy of this assessment is enhanced further when central circulatory factors such as changes in HR are considered.

Animals↗

PubMed1993

Anterior tooth position and motivation for early treatment.

During 1989-90, 473 parents of children being screened at an orthodontic graduate clinic completed a self-report form about the child's dental/facial appearance, reasons for seeking care and referral paths. Almost all (85%) of the 313 parents of children under the age of 16 years expressed concern about the appearance of the child's teeth, and 44% reported the child had been teased about this. Only 14% of the parents reported that it was the child who had first noticed the need for treatment. The rank order of reasons for seeking treatment were appearance of teeth (85%), advice of dentist (73%), and appearance of face (46%). Using logistic regression, overjet and malalignment were observed to be significant predictors of the parent-report of the child being teased (odds ratios, OR, 5.5 and 2.4, respectively). Overjet predicted citing facial appearance as the reason for seeking treatment (OR 2.9), while age predicted patient-referral (OR 2.2) and overjet predicted parental referral (OR 3.0). Increased overjet is an important focus for early treatment and might accordingly be expected to influence the value of early intervention.

Adolescent↗

PubMed1993

Recovery following orthognathic surgery: mandibular bilateral sagittal split osteotomy and Le Fort I osteotomy.

Thirty-eight patients, who underwent orthognathic surgery, reported their recovery period upon returning to work or school and returning to full activity. Twenty-six patients had isolated bilateral sagittal split osteotomies (BSSO) and 12 had isolated Le Fort I osteotomies (LFI). At 1 to 2 weeks postoperatively, 50% of the BSSO group had returned to work or school while none of the LFI group had returned. By 3 to 4 weeks, 81% of the BSSO group had returned to work or school while nearly one half of the LFI group still had not returned. The BSSO group returned to full activity earlier than the LFI group, although the differences were not statistically significant. Hemoglobin, hematocrit, weight, and vital signs were determined preoperatively and for 6 weeks postoperatively. The LFI group had a larger mean estimated blood loss, length of operation, and weight loss.

Absenteeism↗

PubMed1993

Cephalometric measures as indicators of facial attractiveness.

Orthodontic treatment is frequently undertaken to improve facial appearance. However, the contribution of the components of malocclusion to perceptions of attractiveness is not clear. This study uses three panels of judges--undergraduates, dental students, and orthodontic residents--to quantify the associations between common objective measures of dental and skeletal anteroposterior disproportion and subjective perceptions of facial attractiveness. Consistent and similar correlations between anteroposterior measures and facial attractiveness rankings are shown for all three panels, with overjet being most strongly associated with rankings of attractiveness.

Adolescent↗

PubMed1992

Soluble anti-mu monoclonal antibodies prime resting B cells to secrete immunoglobulins in response to interleukins-4 and -5.

Soluble anti-immunoglobulin (Ig) antibodies have been generally found to inhibit Ig secretion in B cells, via largely unknown mechanisms. To investigate this phenomenon further a two-step culture system was used in which B cells are primed for 24-72 h with various soluble monoclonal or polyclonal anti-Ig antibodies: after washing the cells were placed in readout cultures with a combination of interleukin (IL)-5 and IL-4. Using this protocol B cells primed with (mitogenic or nonmitogenic) anti-mu monoclonal antibodies differentiated into large numbers of IgM-secreting cells, comparable to responses to lipopolysaccharide. In contrast, priming with polyclonal rabbit anti-Ig or monoclonal anti-kappa antibodies, markedly inhibited Ig secretion induced by IL-4 + IL-5. In addition, anti-mu was markedly inhibitory if left in the readout cultures with the two lymphokines. These results, therefore, indicate that appropriate cross-linking of surface IgM receptors on B cells can prime the cells to secrete Ig when they are restimulated by T cell-derived lymphokines in the absence of anti-mu. In contrast co-ligation of both surface IgM and surface IgD receptors apparently results in powerful inhibition of Ig secretion, which is not reversed by stimulation with IL-4 plus IL-5.

Animals↗

PubMed1992

Positional changes of the mandibular condyle assessed by three-dimensional computed tomography.

This investigation was designed to test the validity and reliability of three-dimensional computed tomography (3-D CT) for quantification of positional changes of the condyle in a laboratory model. The model consisted of a mounted dried human skull and a mandibular condyle attached to a micromanipulator. Controlled changes in condylar position were made and the condyle/fossa was imaged. Positional changes were measured by triangulation methods based on specific 3-D CT landmarks. The data were analyzed using descriptive statistics, analyses of variance to evaluate the sources of variability, and linear contrasts to evaluate the differences between observed and expected values. The results indicated that selection of appropriate anatomic landmarks for assessment of movement influences technique accuracy. The data also indicate that 3-D CT is most accurate in detecting inferior condylar movements. Lateral and posterior movements were assessed with less accuracy than the inferior positional changes. The clinical significance of these differences has yet to be determined.

Analysis of Variance↗