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Biomedical subjects

C Phillips

Publications and source records attributed to C Phillips.

At least 127 records · Page 7Linked to original sources

Inhibition of diabetic nephropathy by a GH antagonist: a molecular analysis.

Streptozotocin-treated C57B1/SJL mice developed glomerular hypertrophy and light microscopic lesions mimicking human diabetic glomerulosclerosis. In contrast, there were no glomerular hypertrophy and lesions in diabetic mice transgenic (TG) for a mutated growth hormone (bGH-G119K) that competes with native endogenous GH and results in dwarfism. We examined the molecular events underlying these findings. The non-transgenic (non-TG) diabetic mouse glomeruli had an increase in mRNA coding for alpha 1IV collagen, laminin B1, TGF-beta 1, 72 kDa collagenase, and TIMP-3. In contrast, glomerular type IV collagen and laminin B1 mRNA levels were normal in diabetic TG dwarf mice. However, the 72 kDa gelatinase, TIMP-3, and TGF-beta 1 mRNAs were elevated in the diabetic dwarfs. Type IV collagen and laminin accumulated in the glomeruli of diabetic non-TG, but not of diabetic dwarf mice, by immunofluorescence microscopy, confirming the mRNA data. GH binding protein mRNA levels were comparable in glomeruli from dwarf and non-TG mice, both diabetic and non-diabetic. We did not detect GH receptor mRNA in glomeruli. These data suggest that diabetic glomerulosclerosis is associated with an increase in type IV collagen and laminin synthesis, and that these changes do not occur in mice transgenic for bGH119K, a functional antagonist of GH. The increase of 72 kDa gelatinase, TIMP-3 and TGF-beta 1 mRNAs, independent of GH, suggested that these changes induced by hyperglycemia were not sufficient for the induction of glomerulosclerosis.

Animals↗

Middle fossa cyst presenting as a delayed complication of temporal lobectomy: case report.

Symptomatic middle fossa cysts have not previously been described as complications of temporal lobectomy that has been performed to control complex partial seizures. A patient is described who developed a middle fossa cyst causing mass effect, intracranial hypertension, and neurological deterioration > 2 years after temporal lobectomy for complex partial seizures. An enlarging cyst with cerebrospinal fluid imaging characteristics was detected on neuroimages 1 year before neurological deterioration. The patient was treated by the insertion of a cystoperitoneal shunt for cerebrospinal fluid diversion. The potential causes of an acquired arachnoid cyst and hydrocephalus are discussed.

Adult↗

Quality in provision of forensic psychiatric services: room for improvement.

Highlights some of the tensions which impede the development of an effective and efficient system of service delivery in forensic psychiatry. Reports on an investigation exploring the quality of care in a relatively small unit providing forensic psychiatric care in a secure setting and the constraints which impede the development of such services. Discusses the findings from the investigation which point to the need for the organizational structure surrounding forensic psychiatric care to be altered so that there are no perverse incentives for purchasers of services and to enable the contracting process, considering both cost and quality issues, to take place on a level playing field.

Australia↗

Orthognathic surgery: a hierarchy of stability.

The stability and predictability of orthognathic surgical procedures varies by the direction of surgical movement, the type of fixation, and the surgical technique employed, largely in that order of importance. The most stable orthognathic procedure is superior repositioning of the maxilla, closely followed by mandibular advancement in patients in whom anterior facial height is maintained or increased. (If facial height is decreased by upward rotation of the chin, stability is compromised). The combination of moving the maxilla upward and the mandible forward is significantly more stable when rigid internal fixation is used in the mandible. Forward movement of the maxilla is reasonably stable, with or without rigid internal fixation, but mandibular setback often is not stable, and downward movement of the maxilla that creates downward rotation of the mandible is unstable. For mandibular setback, the inclination of the ramus at surgery appears to be an important influence on stability. It has been suggested that both interpositional synthetic hydroxyapatite grafting and simultaneous ramus osteotomy improve the stability of downward movement of the maxilla, but this has not been well documented. In two-jaw Class III surgery, the stability of each jaw appears to be quite similar to that of isolated maxillary advancement or mandibular setback. The least stable orthognathic procedure is transverse expansion of the maxilla. Although surgically assisted rapid palatal expansion has been suggested as a more stable alternative to segmental Le Fort I osteotomy, the patterns of movement resulting from the two procedures are different, and differences in stability have not been established.

Humans↗

The crystal structure of the catalytic domain of human urokinase-type plasminogen activator.

BACKGROUND: Urokinase-type plasminogen activator (u-PA) promotes fibrinolysis by catalyzing the conversion of plasminogen to the active protease plasmin via the cleavage of a peptide bond. When localized to the external cell surface it contributes to tissue remodelling and cellular migration; inhibition of its activity impedes the spread of cancer. u-PA has three domains: an N-terminal receptor-binding growth factor domain, a central kringle domain and a C-terminal catalytic protease domain. The biological roles of the fibrinolytic enzymes render them therapeutic targets, however, until now no structure of the protease domain has been available. Solution of the structure of the u-PA serine protease was undertaken to provide such data. RESULTS: The crystal structure of the catalytic domain of recombinant, non-glycosylated human u-PA, complexed with the inhibitor Glu-Gly-Arg chloromethyl ketone (EGRcmk), has been determined at a nominal resolution of 2.5 A and refined to a crystallographic R-factor of 22.4% on all data (20.4% on data > 3 sigma). The enzyme has the expected topology of a trypsin-like serine protease. CONCLUSIONS: The enzyme has an S1 specificity pocket similar to that of trypsin, a restricted, less accessible, hydrophobic S2 pocket and a solvent-accessible S3 pocket which is capable of accommodating a wide range of residues. The EGRcmk inhibitor binds covalently at the active site to form a tetrahedral hemiketal structure. Although the overall structure is similar to that of homologous serine proteases, at six positions insertions of extra residues in loop regions create unique surface areas. One of these loop regions is highly mobile despite being anchored by the disulphide bridge which is characteristic of a small subset of serine proteases namely tissuetype plasminogen activator, Factor XII and Complement Factor I.

Amino Acid Sequence↗

The Short Form-36 is preferable to the SIP as a generic health status measure in patients undergoing elective total hip arthroplasty.

OBJECTIVE: To assess the comparative usefulness of the Short Form-36 (SF-36) and the Sickness Impact Profile, (SIP) as generic health status measures in total hip arthroplasty. METHODS: Analysis of preoperative and 3-month data of 54 consecutive patients undergoing total hip replacement for osteoarthritis or rheumatoid arthritis. Instruments were mailed to patients preoperatively and 3 months postoperatively. RESULTS: In 10 of the 12 SIP subscales, but just 1 of the 8 SF-36 subscales, more than 40% of the patients had scores of zero. On a 100-point scale, the median global SIP was 12 (range 0-40) whereas the median global SF-36 was 50 (range 10-85). This indicates that many items of the SIP were not germane to patients undergoing joint arthroplasty. The global and, particularly, the physical dimensions of the SF-36 were more responsive than their SIP counterparts, as measured both by the standardized response mean (1.26 and 0.88, respectively) and the correlation with self-perceived improvement in quality of life (r = 0.37 and 0.26, respectively). The SF-36, but not the SIP, discriminated between patients with relatively good physical performance at 3 months with respect to their ability to work, to play sports, or to garden. CONCLUSION: The SF-36 is briefer, more relevant, and more responsive than the SIP and is preferable as a generic health status measure in patients undergoing elective hip arthroplasty. The SF-36 should be tested in other populations as well as other conditions to determine whether it is a superior generic health status instrument for evaluative research in orthopedic surgery.

Aged↗

Short- and long-term outcome of esophageal perforation.

Esophageal perforation is an important complication of endoscopy and dilation, but few data are available regarding long-term outcome in these patients. Thirty-one consecutive patients with esophageal perforation were studied. Long-term outcome was determined by office follow-up and questionnaires via mail or telephone. The study group included 16 men and 15 women with a mean age of 61 +/- 4 years. Instrumentation was the principal cause of perforation (77%), and pain was the principal symptom in the majority of cases. However, some patients reported no pain, their only symptom being shortness of breast or dysphagia on swallowing saliva. Contrast examinations were used to establish the diagnosis, but results were initially negative in 3 of 27 patients (11%). Seven patients were treated nonsurgically (nasogastric drainage, antibiotics, and intravenous alimentation). Fourteen patients underwent primary closure of the esophageal rent. Six patients underwent surgical drainage, 3 underwent total esophagectomy, and 1 died during surgery before the esophagus was exposed. Thirty-day mortality was 6.4%. Mean hospital stay was 26 +/- 5 days. Postdischarge follow-up was available in 28 of the 29 patients (97%) surviving initial hospitalization, and the mean follow-up was 47 +/- 9 months. Nineteen patients had persistent dysphagia, and 6 underwent dilation again. One of these patients had a second perforation. Contrary to results of some earlier studies, the mortality from esophageal perforation was low in our study because of early intervention in suspected cases. Results of contrast studies are sometimes negative in the early stages after perforation, and studies may need to be repeated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The accuracy of video imaging in orthognathic surgery.

Video imaging is an important emerging technology in planning orthognathic surgery and educating patients about the esthetic effects of treatment. The presurgical cephalograms of 56 patients, 41 with mandibular advancement alone and 15 with mandibular advancement plus genioplasty, were digitized, and the computer-generated soft tissue "line drawing" predictions were compared with the actual posttreatment cephalograms. Video images of the patients' presurgical lateral view were obtained, and two experienced clinicians compared the computer generated video image predictions with the actual posttreatment profile. Video images judged very good or excellent were considered acceptable for treatment planning; 60% to 83% met this criterion, depending on the profile area viewed. The percentage of acceptable images in the lower lip, labiomental fold, and chin area decreased with the addition of a genioplasty. The predicted and actual posttreatment soft tissue line drawings were quite similar for all areas except for the lower lip region, where statistically significant differences were noted, with the predicted lower lip more retrusive and thinner than the actual contours. For the lower lip and chin, a 2 mm or more discrepancy was observed in 20% of the patients. In all cases, the actual image was judged more esthetic than the predicted image, allaying fears of unrealistically optimistic computer generated predictions.

Adult↗

The randomized clinical trial as a powerful means for understanding treatment efficacy.

The comparison of technologies, ie, alternative ways to accomplish the same aim, is inherently difficult. In orthodontics, technology covers a wide spectrum of areas: variations in treatment approach, appliances, wires, diagnostic procedures, and patient management techniques. Clinical trial methodology has been developed to minimize the effect of bias and to provide more objective answers to questions of comparative efficacy and benefits of particular treatments or procedures. The randomized controlled clinical trial (RCT) is now generally considered the strongest research design for the comparison of treatments. This report reviews four issues that should be addressed in planning an RCT: defining the study cohort, selecting the treatment allocation technique, estimating sample size, and performing the trial.

Data Interpretation, Statistical↗

Stability of the palatal rugae as landmarks for analysis of dental casts.

The aims of this study were to determine if the palatal rugae are stable during normal growth, and whether treatment with either headgear or functional appliances affects the position of the rugae. Initial and 15-month recall dental casts of 94 patients enrolled in a study of early Class II treatment were evaluated. The children had been randomly assigned to one of three groups: control (n = 34), headgear (n = 30), and functional appliance (n = 30). Landmarks on the palatal raphe and palatal rugae were recorded using the Reflex Metrograph. A median palatal plane was constructed using the digitized raphe points as reference. Offsets from this plane to the ruga points and transverse and anteroposterior linear distances between ruga points were obtained for all casts. Transverse offsets and linear distances between medial points of the first rugae and the anteroposterior distances between the medial points of the second and third rugae did not show statistically significant changes in all groups. Significant changes were observed for the lateral points of the rugae, particularly in the headgear group. The medial rugae appear to be suitable anatomic points for the construction of stable reference planes for longitudinal cast analysis.

Analysis of Variance↗

The influence of video imaging on patients' perceptions and expectations.

Seventy-four patients, ranging in age from 15 to 50 and presenting with a moderate to severe dentofacial deformity requiring orthognathic surgery, were randomly assigned to a video imaging or a standard case presentation (CP) group. Motives for treatment did not differ significantly between the video image and standard CP groups. Two weeks after the case presentation, 60% of the standard CP group and 74% of the video image group ranked the anticipated change in facial appearance as an important factor in making a treatment decision. Seventy percent of the standard CP group and 83% of the video image group agreed with the statement that surgery would be necessary to correct their problem. In the standard CP group, 47% of the patients ranked dental casts as the most helpful physical record in making a treatment decision, and 46% said the acetate profile tracing was the most helpful tool for understanding what to expect from treatment. In the video imaging group, 42% of the patients said the video imaging presentation was the most helpful tool in making a treatment decision, and 39% of the patients said it was the most helpful tool for understanding treatment expectations. The proportion of patients in the video image case presentation group with elevated self-image expectations following treatment was significantly higher (P = .045) than in the standard case presentation group. The presentation of video images appears to be a valuable information source for conveying treatment options to patients, but caution may be needed to prevent elevated or possibly unrealistic treatment expectations.

Adolescent↗

Self-concept, Class II malocclusion, and early treatment.

Increased overjet has been associated with teasing, negative stereotyping, and low self-concept. Early treatment for children with Class II malocclusion is often recommended under the assumption that an improved dental appearance may benefit a child by increasing his or her social acceptance and hence self-concept. The self-concept of 208 patients, age 7 to 15 years and with increased overjet, was measured before treatment using the Piers-Harris self-concept scale; a subset of 87 of these children were measured again after 15 months of early growth modification. The mean self-concept score for these children was above the population norm, and there was no association between the child's score and the magnitude of his or her overjet or age. Although some significant associations were found between Class II malocclusion features and self-concept scores, the explained variation in self-concept scores was low (R2 from 5% to 8%). There was no change in the mean self-concept score of these children during early treatment, nor was there any association between reduction of Class II malocclusion features and improved self-concept. These findings suggest that children with Class II malocclusion do not generally present for treatment with low self-concept and, on average, self-concept does not improve during the brief period of early orthodontic treatment.

Adolescent↗

The structure of social engagement among nursing home residents.

This research tests the reliability and construct validity of social engagement, a new quality of life measure embedded in the federally mandated Resident Assessment Instrument (RAI) for the nursing home population. The sample consisted of 1,848 residents from 268 homes in 10 states with data collected by trained research nurses. Three resident groups were formed based on residents' cognitive and ADL functioning. Social engagement was significantly related to average time spent in activities across all three groups. We hypothesized a four-factor model with social engagement distinct from mood problems, conflicted relationships, and behavior problems. LISREL confirmatory factor analysis found the data to be consistent with this hypothesis (Fit Index > .98). Intercorrelations between factors showed that for high-functioning residents, engagement was negatively related to conflict but was positively related to conflict among the most impaired. The validity of the social engagement measure and its stability across types of residents suggest its potential utility as a marker of nursing home quality.

Activities of Daily Living↗

Evaluating Alzheimer's special care units: reviewing the evidence and identifying potential sources of study bias.

Special Care Units (SCUs) for Alzheimer's disease have been proliferating in long-term care, but their effectiveness remains unproven. This review summarizes the published studies, presents and discusses the many potential sources of bias that pose special problems for SCU research, and proposes strategies for conducting and interpreting future outcome studies in this difficult research setting.

Aged↗