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Biomedical subjects

D Zurakowski

Publications and source records attributed to D Zurakowski.

160 records · Page 9Linked to original sources
PubMed1995

Neutral endopeptidase modulation of septic shock.

Neutral endopeptidase (NEP; EC. 3.4.24.11) is a type 2 cell surface metalloprotease known by a variety of eponyms, including enkephalinase, common acute lymphoblastic leukemia antigen, and CD10. Identified substrates are largely neural or humoral oligopeptide agonists, and the enzyme functions to terminate signaling by degrading the ligand, analogously to acetylcholine/acetylcholinesterase. Targeted disruption of the NEP locus in mice results in enhanced lethality to endotoxin shock with a pronounced gene dosage effect. The site(s) of action appears downstream from release of tumor necrosis factor and interleukin-1 since NEP-deficient animals demonstrate increased sensitivity to these mediators as well. This unexpected finding indicates an important protective role for NEP in septic shock.

Animals↗
PubMed1995

Effect of mitomycin C and fluorouracil-supplemented trabeculectomies on the anterior segment.

OBJECTIVES: To determine whether there is increased risk to the corneal endothelium when mitomycin C is used in trabeculectomy surgery instead of fluorouracil, and whether these agents play a role in accelerating cataract formation. DESIGN, SETTINGS, AND PARTICIPANTS: We analyzed the corneal endothelium and the lens preoperatively and postoperatively in 30 eyes of 21 patients who underwent either a fluorouracil- or mitomycin C-supplemented trabeculectomy. RESULTS: No significant differences were found between these two groups in the rate of cataract progression, magnitude of endothelial cell loss, or appearance of endothelial cell morphologic characteristics. Endothelial cell loss accounted for approximately 7% to 8% of the preoperative counts in both groups. In addition, four (27%) of 15 eyes in each group showed evidence of cataract progression as graded by the Lens Opacities Classification System II. CONCLUSION: Fluorouracil- and mitomycin C-supplemented trabeculectomies cause similar changes in the lens and corneal endothelium.

Aged↗
PubMed1995

[Local recurrence of soft tissue sarcoma of the extremities and trunk].

Soft tissue sarcomas (STS) tend to recur locally. In a series of 140 patients operated on during the past two decades with STS of the extremities and trunk, prognostic factors influencing local recurrence were determined. Statistical significance was evaluated for the quality of surgical resection (P < 0.001), regional positive lymph nodes (P = 0.03), and adjuvant radiotherapy (P = 0.01) [for resection without wide margins (R1) and low-grade (G3) tumors]. In 1988, the surgical procedure was standardized. After 1987, local recurrence decreased significantly (P < 0.001). In subfascial tumors, local recurrence occurred far less in cases of compartmental resection than with wide excision. These data indicate that the course of patients with STS can be beneficially influenced by optimal therapy. Resection with wide margins in all three dimensions is the aim of sarcoma surgery. Postoperative radiation therapy is indicated in the case of R1 resection.

Adolescent↗
PubMed1995

Cartilaginous abnormalities and growth disturbances in Legg-Calvé-Perthes disease: evaluation with MR imaging.

PURPOSE: To evaluate the magnetic resonance (MR) imaging appearance of cartilaginous abnormalities in Legg-Calvé-Perthes (LCP) disease and their association with growth arrest. MATERIALS AND METHODS: Twenty-seven MR images and radiographs of 25 hips in 23 patients were reviewed for epiphyseal, physeal, and metaphyseal abnormalities. Follow-up radiographs (mean time, 20.5 months) were evaluated for growth arrest. RESULTS: Epiphyseal abnormality seen in 74% of cases was not related to growth disturbances. Transphyseal bone bridging on MR images, the strongest predictor of abnormal growth (P < .01), was found in 63% of femurs. MR imaging helped detect physeal abnormalities with greater sensitivity (94%), specificity (89%), and positive predictive value (94%) than radiography. Metaphyseal extension of physeal cartilage seen in 81% of cases was associated with growth abnormality (P < .01), particularly when detected at radiography. CONCLUSION: Cartilaginous physeal and metaphyseal abnormalities in LCP disease are common and frequently result in growth arrest.

Adolescent↗
PubMed1995

[Pulmonary artery banding in the treatment of univentricular heart. Results and therapeutic implications for cavopulmonary derivations].

Eighty-six children under one year of age with univentricular hearts associated with increased pulmonary flow underwent pulmonary artery banding as the first stage of palliative therapy. Fifteen patients also had treatment of coarctation of the aorta at the same time and an atrial septal defect was treated in 13 patients. Twenty-seven patients underwent a Fontan procedure secondarily. The mean follow-up was 42.6 +/- 45.5 months; 8 patients were lost to follow-up. Twenty-three patients died during the whole of the study period. The global actuarial survival rate was 69.6 +/- 5% at 5 years. The 3 year survival rate was 56 +/- 12% in patients with anatomical right ventricles compared with 74.4 +/- 5.7% and 69.5 +/- 7.3% at 3 and 5 years respectively in those with anatomical left ventricles (p < 0.01). The presence of coarctation of the aorta reduced the 5 year actuarial survival rate to 25.4 +/- 12.8% (p < 0.01). Subaortic stenosis either at the time of initial presentation or occurring during pulmonary banding was associated with a 5 year survival of 58.3 +/- 13.7% (p < 0.01). Uni- and multivariate analysis demonstrated poor prognostic risk factors. On univariate analysis, they were the residual mean pulmonary pressures after banding, coarctation of the aorta, subaortic stenosis and a restrictive atrial septal defect. Independent risk factors on multivariate analysis were the residual pulmonary pressures after banding, coarctation of the aorta, the necessity of operation in the neonatal period and the need for reoperation for reason other than for a cavopulmonary connection. The feasibility of a Fontan procedure was reduced when subaortic stenosis was observed at any time. Only 17.5% of patients were free of reoperation during this study for whom banding remained the only palliative procedure. In conclusion, a programme of cavopulmonary connection should be envisaged from the initial presentation of these patients. The different stages of treatment with this objective in mind should aim to preserve myocardial function and keep pulmonary resistances low. Therefore, pulmonary artery banding should be rejected in cases with coarctation of the aorta and/or subaortic stenosis. Similarly, early conversion with a Glenn type bidirectional anastomosis allows adaptation of myocardial function for a secondary total cavopulmonary connection.

Analysis of Variance↗
PubMedDate not supplied

Database prescan: a time-efficient alternative to brain MRI autoprescan.

The purpose of this study was to determine the feasibility of database prescan as an alternative to conventional autoprescan in pediatric brain MRI. Autoprescan parameters [receiver levels and transmit gain (TG)] were analyzed prospectively in 236 pediatric brain MRI studies. Paired t test and linear regression analysis were performed to determine predictability of autoprescan parameters by database-generated parameters. Signal-to-noise ratio, image quality, and potential time efficiency of database-generated parameters were assessed. No statistical difference (P = .13) and a high correlation between the TG of the axial fast spin echo (FSE) proton density (PD) and axial FSE T2-weighted sequences (r = .92) was seen. Strong correlations were noted between the TG of the sagittal T1-weighted and the TG of the axial FSE PD (r = .79), axial FSE T2-weighted (r = .81), and contrast-enhanced T1-weighted (r = .78) sequences. The receiver levels did not change significantly between sequences. Quantitative and qualitative analyses revealed no differences in the signal-to-noise ratios of the autoprescan and the database-predicted prescan parameters. Implementation of database prescan could improve time efficiency by 28 to 33%. Autoprescan parameters can be predicted by using database-generated information while preserving the diagnostic image quality of the study. Incorporation of database prescan into commercial MRI systems could improve MRI time efficiency and patient throughput.

Adolescent↗
PubMedDate not supplied

Efficacy of simulated epinephrine-containing epidural test dose after intravenous atropine during isoflurane anesthesia in children.

BACKGROUND AND OBJECTIVES: A double-blind, randomized study was performed to investigate heart rate (HR) and blood pressure responses to 2 doses of intravenous (IV) epinephrine (0.5 and 0.75 microg/kg) in 61 children, ages 3 months to 12 years. METHODS: Anesthesia was maintained with isoflurane (age-adjusted 1 minimal alveolar concentration [MAC]) in oxygen. All patients received IV atropine (10 microg/kg) and 5 minutes later were randomized to receive IV solutions (0.1 mL/kg) containing 1% lidocaine (n = 19, group I) with saline; lidocaine 1% with epinephrine 0.5 microg/kg (n = 21, group II); or lidocaine 1% with epinephrine 0.75 microg/kg (n = 21, group III). HR was recorded at 0, 15, 30, 45, 60, 90 seconds, and 2, 3, 4, and 5 minutes after test-dose injection. Systolic blood pressure (SBP), diastolic blood pressure, and end-tidal carbon dioxide were recorded at steady-state isoflurane anesthesia, after the injection of atropine, and at 45-second intervals after test-dose injections. RESULTS: Median maximum increases in HR were similar in groups II and III at 19 and 22 beats per minute (beats/min), respectively. An HR increase of > or =10 beats/min was observed in 19 of 21 patients who received 0.5 microg/kg epinephrine and 21 of 21 patients receiving 0.75 microg/kg. None of the patients in group I developed HR increases > or =10 beats/min. SBP increased > or =15 mm Hg in 17 of 21 patients in group II and 19 of 21 in group III. No dysrhythmias or T-wave amplitude change was noted. CONCLUSIONS: A simulated epidural test dose containing lidocaine 1 mg/kg with epinephrine 0.75 microg/kg, administered IV following atropine, may reliably increase HR to indicate unintentional injection into epidural vessels of children anesthetized with 1 MAC isoflurane.

Anesthesia, Inhalation↗
PubMedDate not supplied

Diagnostic performance of clinical examination and selective magnetic resonance imaging in the evaluation of intraarticular knee disorders in children and adolescents.

To determine the diagnostic performances of clinical examination and selective magnetic resonance imaging in the evaluation of intraarticular knee disorders in children and adolescents we compared them with arthroscopic findings in a consecutive series of pediatric patients (< or = 16 years old). Stratification effects by patient age and magnetic resonance imaging center were examined. There were 139 lesions diagnosed clinically, 128 diagnosed by magnetic resonance imaging, and 135 diagnosed arthroscopically. There was no significant difference between clinical examination and magnetic resonance imaging with respect to agreement with arthroscopic findings (clinical examination, 70.3%; magnetic resonance imaging, 73.7%), overall sensitivity (clinical examination, 71.2%; magnetic resonance imaging, 72.0%), and overall specificity (clinical examination, 91.5%; magnetic resonance imaging, 93.5%). Stratified analysis by diagnosis revealed significant differences only for sensitivity of lateral discoid meniscus (clinical examination, 88.9%; magnetic resonance imaging, 38.9%) and specificity of medial meniscal tears (clinical examination, 80.7%; magnetic resonance imaging, 92.0%). For magnetic resonance imaging, children younger than 12 years old had significantly lower overall sensitivity (61.7% versus 78.2%) and lower specificity (90.2% versus 95.5%) compared with children 12 to 16 years old. There was no significant effect of magnetic resonance imaging center. In conclusion, selective magnetic resonance imaging does not provide enhanced diagnostic utility over clinical examination, particularly in children, and should be used judiciously in cases where the clinical diagnosis is uncertain and magnetic resonance imaging input will alter the treatment plan.

Adolescent↗
PubMedDate not supplied

Functional and radiographic outcome of juvenile osteochondritis dissecans of the knee treated with transarticular arthroscopic drilling.

Management of juvenile osteochondritis dissecans is controversial. The purpose of this study was to evaluate the functional and radiographic outcomes of transarticular arthroscopic drilling for isolated stable, juvenile osteochondritis dissecans lesions of the medial femoral condyle with an intact articular surface after 6 months of nonoperative management had failed. We reviewed 30 affected knees in 23 skeletally immature patients (mean age, 12.3 years; range, 8.5 to 16.1) at an average follow-up of 3.9 years (range, 2.0 to 7.2). Functional outcome was determined using the Lysholm score and radiographic outcome was determined using lesion size, and the radiographic score of Rodegerdts and Gleissner. There was significant improvement in the mean Lysholm score (from 58 to 93). There was significant improvement in the mean lesion size on anteroposterior (4.5 +/- 5.8 mm decrease) and lateral (8.4 +/- 8.1 mm decrease) radiographs. There was also significant improvement in the mean radiographic score (from 3.0 to 1.9). Radiographic healing was achieved in all patients at an average of 4.4 months after drilling (range, 1 to 11 months). Linear regression analysis revealed that younger age was an independent, multivariate predictor of Lysholm score improvement. There were no apparent surgical complications.

Adolescent↗
PubMedDate not supplied

Assessment of flexibility in young female skaters with the modified Marshall Test.

A cross-sectional study was performed on 62 female precision ice skaters to determine whether a modified Marshall Test is a reliable measure of constitutional flexibility in young female athletes. These skaters were from the Colonial Precision Skating Club of Acton, Massachusetts. Chronologic age ranged from 7 to 18 years with an average of 12.5 years (SD, 2.6 years). All skaters were assigned a modified Marshall Test score (Micheli's 5-point score) for both left and right thumbs. This score was then compared with their hamstring-flexibility measure (left and right) and the external and internal rotation (ER and IR, respectively) of their shoulders. Positive linear relationships were found between Micheli's 5-point score (MS) on the right side and both left and right hamstring and shoulder flexibility. However, the left-side MS was positively correlated only with the left hamstring and left shoulder flexibility. We conclude that the modified Marshall test is a reliable predictor of upper and lower extremity flexibility in female adolescent athletes.

Adolescent↗
PubMedDate not supplied

Osteonecrosis of the femoral head associated with slipped capital femoral epiphysis.

We performed a retrospective analysis of 212 patients (299 hips) with slipped capital femoral epiphysis (SCFE) over a 9-year period to assess the incidence of osteonecrosis of the femoral head. Risk factors for the occurrence of osteonecrosis and the influence of treatment on the development of osteonecrosis were determined. Osteonecrosis occurred in 4 hips with unstable SCFE (4/27) and did not occur in hips with stable SCFE (0/272). The proportion of hips in which osteonecrosis developed was significantly higher among the unstable hips (4/27 vs. 0/272, p < 0.0001). Among those with an unstable hip, younger age at presentation was a predictor of a poorer outcome. Magnitude of the slip, magnitude of reduction, and chronicity of the slip were not predictive of a poorer outcome in the unstable group. In situ fixation of the minimally or moderately displaced "unstable" SCFE demonstrated a favorable outcome. We have identified the hip at risk as an unstable SCFE. The classification of hips as unstable if the epiphysis is displaced from the metaphysis or if the patient is unable to walk is most useful in predicting a hip at risk for osteonecrosis.

Age Factors↗
PubMedDate not supplied

Early failure of Pavlik harness treatment for developmental hip dysplasia: clinical and ultrasound predictors.

A cohort of 93 patients with developmental dysplasia of the hip (DDH) treated with a Pavlik harness were evaluated to determine predictors of treatment failure. Failure was defined as failure to achieve or maintain hip reduction in the Pavlik harness. Of 93 patients (137 hips), 17 (26 hips) failed Pavlik harness treatment. Univariate risk factors for failure included bilaterality, initial clinical exam, and initial ultrasound (US) percent coverage. Clinical exam and initial percent coverage were multivariate risk factors for failure. Among initially clinically dislocatable hips, a low initial US alpha angle correlated with an increased likelihood of failure. All (6/6) patients with an initially irreducible hip and an initial coverage of <20% by US eventually failed treatment. Gender, side of pathology, and age at diagnosis and initiation of treatment did not correlate with failure. Irreducibility by physical exam combined with US coverage of <20% identified a patient group that uniformly failed Pavlik harness treatment. These patients may be candidates for alternative bracing, traction, or closed or open reduction.

Age Factors↗
PubMedDate not supplied

Normal ranges of scapholunate distance in children 6 to 14 years old.

SUMMARY: The purpose of this study was to determine the normal ranges of scapholunate distance (SLD) applicable to children. Bone age radiographs of 85 children (36 boys, 49 girls) 6 to 14 years of age were used to establish the normal ranges. Repeated-measures analysis of variance revealed significant age and gender differences. Therefore, linear regression was used to determine normal SLD ranges separately for girls and boys based on chronologic age and bone age. SLD normal ranges were similar for chronologic age and bone age. Interobserver and intraobserver agreement was excellent. There was no significant age by gender interaction found, indicating that although boys had significantly longer distances than girls, both showed a similar rate of decreasing SLD distance with age. These results provide age-and gender-based normal ranges of SLD in young children. These results may be useful in assessing traumatic soft tissue injuries about the pediatric wrist. Of note, only three girls and two boys (all 12 years or older) met the adult criterion of normal SLD of < or = 2 mm.

Adolescent↗
PubMedDate not supplied

Femur fractures in children: treatment with early sitting spica casting.

The purpose of this article is to review our experience with early spica casting and determine risk factors for loss of reduction and skin complications. The radiographic and clinical charts of 114 children were retrospectively reviewed. At the time of fracture union, excessive shortening and angular malunion were not significant problems. Loss of reduction and skin complications occurred in 20 and 14% of patients, respectively. In addition to previously described risk factors, we identified spica knee flexion angle < 50 degrees as predictive of eventual loss of reduction and found that > 2 cm of initial shortening was not a contraindication to early spica casting. Factors associated with skin problems included younger age and abuse as a mechanism of injury. In our opinion, early spica casting is the treatment of choice for all isolated, closed femur fractures in otherwise healthy children aged 6 years or younger, regardless of the degree of initial deformity.

Analysis of Variance↗
PubMedDate not supplied

Radiographic appearance of the normal distal tibiofibular syndesmosis in children.

In adults, a tibiofibular clear space (i.e., distance from the incisura fibularis to the medial fibula) of > or = 6 mm or a loss of tibiofibular overlap has been reported to correlate with injury to the distal tibiofibular syndesmosis. We reviewed anteroposterior (AP), lateral, and mortise ankle radiographs from 106 children (50 boys, 56 girls) aged 1-15 years in an attempt to assess whether these criteria are applicable to children. The incisura was detectable at a mean age of 8.2 years for girls and 11.2 years for boys. The range of tibiofibular clear space among the 48 children with a detectable incisura was 2-8 mm; seven (23%) of these 48 children had a clear space of > or = 6 mm in one or more views. The mean age at which the tibiofibular overlap began to appear on the AP view was 5 years for both genders, whereas on the mortise view, it was 10 years for girls and 16 years for boys. The criteria used to evaluate the integrity of the distal tibiofibular syndesmosis in adults do not apply to children in this normal study population.

Adolescent↗