Prediction of postoperative knee flexion in Insall-Burstein II total knee arthroplasty

Postoperative knee flexion in patients undergoing Insall-Burstein-II total knee arthroplasty at 2 years was evaluated regarding two basic questions: what groups of patients gain or lose the most flexion and what groups of patients have the best or worst postoperative flexion. Thirteen preoperative variables (maximum flexion, flexion arc, tibiofemoral angle, quadriceps strength, extensor lag, Knee Society score, Knee Society patient assessment, gender, age, height, weight, diagnosis, and surgeon) and four postoperative variable (leg length change, tibiofemoral angle, distance from patella to the joint line, and the tibial prosthesis anteroposterior translation on a lateral radiograph) were used in an attempt to explain postoperative flexion. The analysis was performed on 164 consecutive Insall-Burstein-II total knees in which the data were gathered prospectively on a time oriented medical record database. A regression tree analysis was used to identify several groups of patients, characterized by preoperative factor values, who had markedly above average performance on postoperative flexion. The preoperative factors identified include preoperative flexion, flexion arc, tibiofemoral angle, extensor lag, diagnosis, and age. The only postoperative variable of significance was tibiofemoral angle. Among the potential determinants of postoperative flexion that failed to appear predictive were the Knee Society scores and surgeon. Preoperative flexion is known to be a critical determinant of postoperative flexion in total knee replacement. However, in the current study, preoperative flexion accounted for only half of the difference between the best (122 degrees) and the worst (88 degrees) group, as determined with regression tree analysis.     

Predicting length of stay in an acute psychiatric hospital

OBJECTIVE: Multivariate statistical methods were used to identify patient-related variables that predicted length of stay in a single psychiatric facility. The study investigated whether these variables remained stable over time and could be used to provide individual physicians with data on length of stay adjusted for differences in clinical caseloads and to detect trends in the physicians' practice patterns. METHODS: Data on all patients discharged over two six-month periods were collected at an acute psychiatric inpatient facility. Stepwise multiple regression analyses were conducted on the two datasets. RESULTS: The results from both analyses revealed that five variables significantly predicted length of stay and were stable over time. They were a primary diagnosis of schizophrenia, the number of previous admissions, a primary diagnosis of a mood disorder, age, and a secondary diagnosis of an alcohol- or other drug-related disorder. For some physicians, the mean length of stay of their patients differed significantly from the length predicted by the regression model--generally, it was shorter. CONCLUSIONS: The results demonstrate that patient-related predictors of length of stay in a single psychiatric hospital can be identified using relatively simple statistical procedures and can be consistent across a large dataset and over time.     

Phonosurgery

Phonosurgery is composed of procedures that are intended to maintain or improve the quality of the voice by correcting defects in laryngeal sound production. These procedures are rooted in a rich medical history that dates back to the early 19th century. There has been a recent convergence of physiologic principles of voice production with surgical technique theory. Recognition of this interdependence has provided a catalyst for collaboration among surgeons, scientists, speech pathologists, vocal pedagogists, and performing artists. We live in a society that is linked to effective communication, and there is a growing population of individuals who have professional voice responsibilities as part of everyday life. This has created a need for the recent developments in phonosurgery and its emergence as a subspecialty of otolaryngology.     

Conformal proton therapy for prostate carcinoma

The suppression of apoptosis may contribute to the carcinogenicity of the peroxisome proliferators (PPs), a class of non-genotoxic rodent hepatocarcinogens. Our previous work demonstrated that the PP nafenopin suppressed both spontaneous and transforming growth factor beta1 (TGFbeta1)-induced hepatocyte apoptosis both in vivo and in vitro. Here, we extend these observations by demonstrating the ability of nafenopin to suppress apoptosis induced by other major candidates for the signalling of cell death in the liver. Treatment of rat or mouse hepatocyte monolayers with TGFbeta1 or the DNA damaging drugs etoposide or hydroxyurea induced high levels of apoptosis. Western blot analysis did not support a role for either p53 or p21waf1 in etoposide-induced apoptosis in rat hepatocytes. Treatment of mouse hepatocytes with an agonistic anti-Fas antibody also resulted in an induction of high levels of apoptosis. Pre-addition and continued exposure to nafenopin suppressed apoptosis induced by all three stimuli. Overall, our studies demonstrate that the ability of nafenopin to protect hepatocytes from apoptosis is not restricted to species or apoptotic stimulus. It is possible, therefore, that the PPs may suppress apoptosis by acting on diverse signalling pathways. However, it seems more likely that nafenopin suppresses hepatocyte apoptosis elicited by each death stimulus by impinging on a core apoptotic mechanism.     

The synthesis of symmetrical and unsymmetrical P1/P1' cyclic ureas as HIV protease inhibitors

Cyclic urea SD146, a potent HIV protease inhibitor bearing a flat resistance profile, possessed poor solubility and bioavailability, which precluded further development of the compound. In an effort to improve upon the pharmacokinetic profile of the compound, several analogs modified at the P1/P1' residues were prepared and evaluated. Several of those compounds displayed significant improvement of physical properties.     

Chronic hepatitis in children after liver transplantation: role of hepatitis C virus and hepatitis G virus infections

BACKGROUND/AIMS: Chronic graft hepatitis occurs in 20-30% adults after liver transplantation but the prevalence and causes in children are not known. In adults, hepatitis C virus infection is prevalent prior to transplantation and recurrent infection is a frequent cause of graft dysfunction. The significance of the recently described hepatitis G virus infection remains unproven. The aim of this study was to examine the role of hepatitis C virus and hepatitis G virus infection in chronic graft hepatitis after paediatric liver transplantation. METHODS: The prevalence of graft hepatitis and the role of hepatitis C virus and hepatitis G virus infections in 80 children after liver transplantation have been studied, with a median follow up of 4.4 years (range 0.4 to 10.7), and the persistence of hepatitis G infection in the presence of immunosuppression has been determined. RESULTS: Chronic graft hepatitis was diagnosed in 19/80 (24%) children and was most frequently seen in children transplanted for cryptogenic cirrhosis (71%). There was no significant difference in the prevalence of chronic hepatitis in those transplanted before or after donor anti-HCV screening. Hepatitis C infection occurred in three children transplanted prior to donor screening but in only one was associated with chronic hepatitis. Hepatitis G infection was found in 22/79 (28%) transplant recipients but was not associated with graft hepatitis. In 17/21 children hepatitis G infection persisted for a median of 5.2 years after transplantation. CONCLUSION: Chronic hepatitis occurred in 24% of children after liver transplantation, a similar prevalence to that in adults. Cryptogenic liver disease predisposed to graft hepatitis, but neither hepatitis C nor hepatitis G infection was associated. Hepatitis G virus caused a frequent and usually persistent infection after transplantation.     

Leukoregulin induction of protein expression in human orbital fibroblasts: evidence for anatomical site-restricted cytokine-target cell interactions

The molecular basis for the profound inflammatory response and the accumulation of hyaluronan in orbital connective tissues seen in thyroid-associated ophthalmopathy is unknown. Moreover, the link between the orbital manifestations of Graves' disease and those in the pretibial skin, localized dermopathy, has yet to be established. We have reported recently that leukoregulin, an activated T lymphocyte-derived cytokine, dramatically induces hyaluronan synthesis and prostaglandin-endoperoxide H synthase 2 in human orbital fibroblasts in culture. In the current studies, utilizing giant two-dimensional gel electrophoresis, we find that orbital fibroblasts express constitutively a protein profile that distinguishes them from skin fibroblasts derived from the abdominal wall and from the pretibium. We further demonstrate that leukoregulin, when present in culture medium for 16 hr, up-regulates a set of orbital fibroblast proteins not present in untreated cultures or in fibroblasts from the abdominal wall. However, some of the same protein inductions are present in the pretibial fibroblasts. These leukoregulin-induced changes in protein expression are completely blocked by dexamethasone (10 nM). Our findings are the first to identify proteins that appear to be expressed and differentially regulated in an anatomical site-restricted manner in orbital and pretibial fibroblasts and seem to establish a molecular link between fibroblasts from the orbit and those in pretibial skin.     

Conformational stability of factor VIIa: biophysical studies of thermal and guanidine hydrochloride-induced denaturation

The binding of the multidomain protein factor VIIa (fVIIa) to tissue factor provides the interprotein communication necessary to make fVIIa an efficient catalyst of the initial event in the extrinsic pathway of blood coagulation. We have investigated the stability of individual domains in fVIIa and the influence of Ca2+ and an irreversible active-site inhibitor (FFR-chloromethyl ketone). Equilibrium guanidine hydrochloride (GuHCl)-induced unfolding monitored by tryptophan fluorescence and far-UV circular dichroism (CD) demonstrated that the gamma-carboxyglutamic acid (Gla) domain unfolds at 0.3 M GuHCl and the serine protease (SP) domain at 3 M GuHCl and that Ca2+ is a prerequisite for the formation of an ordered, compact structure in the Gla domain. The loss of amidolytic activity coincides with the first transition, which is stabilized by the active-site inhibitor, and a change in the environment of the active site is demonstrated using a fluorescent inhibitor (DEGR-chloromethyl ketone). Thermal unfolding monitored by differential scanning calorimetry (DSC) reveals that Ca2+ stabilizes the SP domain slightly, increasing the unfolding temperature by 2.7 degrees C. In addition, Ca2+ is required for a large enthalpy change concomitant with unfolding of the Gla domain, and this unfolding enthalpy is only detectable in the presence of the SP domain, indicating some kind of interaction between these domains. Thermal unfolding measured by CD indicates secondary structural changes at the same temperature as the heat absorption in the DSC but only when both the Gla domain and the SP domain are present together with Ca2+ ions. Taken together, these results indicate a Ca2+-dependent interaction between the Gla domain and the SP domain, implying a high degree of flexibility of the domains in free fVIIa. It is also shown that the epidermal growth factor-like domains are stable at elevated temperatures and high GuHCl concentrations. Moreover, already at physiological temperature, subtle structural changes take place which influence the overall shape of fVIIa and are detrimental to its enzymatic activity.     

Indocyanine-green videoangiography of drusen as a possible predictive indicator of exudative maculopathy

OBJECTIVE: Recent studies have shown that indocyanine-green videoangiography (ICG-V) is useful to image occult choroidal neovascularization. The authors studied the ICG-V findings in fellow drusen eyes of patients with unilateral exudative age-related macular degeneration (AMD). The authors also studied the occurrence of exudative changes to determine whether ICG-V is useful in predicting future exudative changes in these eyes with only drusen. DESIGN: Cohort study. PARTICIPANTS: The authors studied 432 consecutive patients diagnosed with unilateral exudative AMD in whom the fellow eye had only drusen by clinical fundus examination and fluorescein angiography. All of these eyes had ICG-V performed. Follow-up data were obtained in all eyes with abnormal indocyanine-green (ICG) angiograms and randomly sampled ICG angiograms of normal eyes. MAIN OUTCOME MEASURES: The initial ICG findings were classified as showing normal or abnormal hyperfluorescence. Abnormal hyperfluorescence eyes were subdivided into focal spots (focal areas of hyperfluorescence < 1 disc area in size) and plaques (areas of hyperfluorescence > 1 disc area). The development of exudative changes in eyes with normal and abnormal hyperfluorescence was compared. RESULTS: Of the 432 fellow eyes, 386 (89%) eyes with drusen had a normal ICG-V study, whereas 46 (10 focal spots and 36 plaques) (11%) eyes had an abnormal ICG-V. Exudative changes occurred in 6 (10%) of 58 normal ICG eyes and 9 (24%) of 38 eyes with abnormal ICG findings during a mean follow-up period of 21.7 months. The difference between drusen eyes with normal ICG angiograms and those with plaques on ICG-V regarding future exudative changes (10% vs. 27%, respectively) was statistically significant (P = 0.038). CONCLUSIONS: Abnormal ICG findings were found in 11% of eyes with clinically and fluorescein angiographically nonsuspicious drusen. The subgroup of patients with plaques on ICG-V had a higher chance of having exudative changes develop. Indocyanine-green videoangiography may be a predictive indicator of future exudative changes in eyes with drusen. A much larger prospective study seems justified.     

Pulmonary function test outcomes in healthy Navajo Native American adolescents

Prediction equations for estimating lung volumes have been determined for Caucasians, African-Americans, and Mexican-Americans. These separate equations were determined because of differences in thoracic morphology between people of various racial groups, making it impossible to use one prediction formula to accurately estimate lung volumes for all individuals. One hundred ninety-one adolescent Navajo children (males, n = 110; females, n = 81) between 11 and 18 yr of age volunteered for the study and underwent a series of pulmonary function tests (PFT). New pulmonary function prediction equations for Navajo youth were generated for estimating pulmonary volumes and capacities that more accurately predict expected PFT outcomes than formulas in common use for Caucasian, Mexican-American, or African-American youth.