Real-time 3-dimensional echocardiographic evaluation of left ventricular volume: correlation with magnetic resonance imaging--a validation study

BACKGROUND

The purpose of our study was to validate the ability of real-time 3-dimensional echocardiography (RT3D) to measure cardiac volume.

METHODS

We studied 25 patients with various cardiac disorders who had a regular heart rhythm and a good precordial echocardiographic window. Each patient underwent complete transthoracic echocardiography (TTE), RT3D, and magnetic resonance imaging (MRI) studies. Left ventricular dimension was calculated from slices of the whole left ventricle obtained by 7 different equidistant azimuth tilts. Planimetry of the endocardial (for volume data) and epicardium (for mass data) surface was performed for each azimuth tilt. The left ventricular end-diastolic volume (LVEDV) and the left ventricular end-systolic volume (LVESV) were calculated. The cardiac mass data were derived with the formula (Epicardial volume - LVEDV) x 1.055. The parameters of LVEDV, LVESV, stroke volume, ejection fraction, and cardiac mass were compared with those derived from MRI.

RESULTS

No statistically significant differences were found between the data from RT3D and MRI (P > or =.05). Good correlations were found between these two methods for left ventricle volume and mass measurements (r from 0.92 to 0.99). However, a weaker correlation was found with larger chamber sizes because extrapolation was necessary for the volume of myocardial segments that were not covered by the small sector angle.

CONCLUSIONS

For data acquisition, RT3D is faster than either TTE or MRI. It is also better than MRI for measuring cardiac volume and mass. To improve results with larger cardiac chamber sizes, enlargement of the sector angle will be necessary.

The anatomy and histology of the rotator interval capsule of the shoulder

Forty-seven rotator interval regions from fetuses and 10 fresh-frozen rotator interval regions from adult cadavers were evaluated by gross dissection and light microscopy. Specimens from adults also were evaluated with ultrasound and magnetic resonance imaging. An analysis of 37 fetal specimens (> 14 weeks gestation) revealed two rotator interval types: Type I (9 of 37) was defined by a contiguous bridge of capsule consisting of poorly organized collagen fibers. A Type II rotator interval (28 of 37) had a complete defect covered by only a thin layer of synovium. Similar to the Type II rotator interval in the fetus, a rotator interval defect was present in six of eight specimens from adults. Histologically, the capsular tissue within the rotator interval consisted of poorly organized collagen fibers in specimens from the fetus and adult. Maximal opening of the rotator interval was seen by ultrasound with internal rotation and downward traction of the hyperextended arm in the coronal, oblique, and sagittal planes. Magnetic resonance imaging of the rotator interval region permitted anatomic evaluation. The complete absence of tissue in 28 of 37 fetuses suggests that the rotator interval defect is congenital. The authors recommend that surgeons carefully evaluate the integrity of the tissue within the rotator interval. When rotator interval closure is desired such as in patients with a persistent sulcus sign after arthroscopic stabilization, suturing the edges of more substantial tissue immediately adjacent to the boundaries of the rotator interval region would seem prudent.

Development of a bench station objective structured assessment of technical skills

OBJECTIVE

We have previously shown that objective structured assessment of technical skills performed in an animal model was an innovative, reliable, and valid method of assessing surgical skills. Our goal was to develop a less costly bench station objective structured assessment of technical skills and to evaluate the feasibility, reliability, and validity of this exam.

METHODS

A seven-station examination was administered to 24 residents. The tests included laparoscopic procedures (salpingostomy, intracorporeal knot tying, closure of port sites) and open abdominal procedures (subcuticular closure, bladder neck suspension, repair of enterotomy, abdominal wall closure). All tasks were performed using life-like surgical models. Residents were timed and assessed at each station using three methods of scoring: a task-specific checklist, a global rating scale, and a pass/fail grade.

RESULTS

Assessment of construct validity, the ability of the test to discriminate among residency levels, found significant differences on the checklist, global rating scale, time for procedures, and pass/fail grade by level of training. Reliability indices calculated with Cronbach's alpha were 0.77 for the checklists and 0.94 for the global rating scale. Overall interrater reliability indices were 0.91 for the global rating scale and 0.92 for the checklists. Total cost for replaceable parts and facilities was $1900.

CONCLUSION

The less costly and more portable bench station objective structured assessment of technical skills can reliably and validly assess the surgical skills of gynecology residents. This type of examination can be a useful tool to identify residents who need additional surgical instruction, provide remediation, and may become a mechanism to certify surgical skill competence.

Post-tonsillectomy bleeding: a meta-analysis

OBJECTIVE/HYPOTHESIS

To reconcile conflicting reports and opinions of the value of preoperative coagulation studies for patients undergoing tonsillectomy.

STUDY DESIGN

Meta-analysis: Articles were identified by MEDLINE search, references from review articles, textbook chapter, and retrieved reports. Independent observers selected prospective trials of patients undergoing tonsillectomy or adenoidectomy and tonsillectomy. Retrospective studies meeting other inclusion and exclusion criteria were included for sensitivity analyses of results.

METHODS

Data were abstracted from studies for an end point of bleeding with normal and abnormal coagulation tests. Four prospective studies met all inclusion and exclusion criteria. These four studies were used in the data synthesis. An additional eight retrospective studies met all other criteria and were used in the sensitivity analysis.

RESULTS

Pooled analysis of 3384 patients revealed a rate of 3.3% (95% confidence interval [CI], 2.5%-4.1%) for post-tonsillectomy bleeding in patients with normal coagulation studies. A rate of 8.7% (95% CI, 1.5%-15.9%) was obtained for bleeding in patients with abnormal coagulation studies. No significant rate difference in post-tonsillectomy bleeding was demonstrated.

CONCLUSION

There is no difference in the rate of post-tonsillectomy bleeding in patients with abnormal coagulation studies as compared with patients with normal coagulation studies obtained preoperatively.

Transthoracic and transesophageal echocardiographic diagnosis of aneurysm of the sinus of Valsalva: a review of five year experience

BACKGROUND

Aneurysms of the sinus of Valsalva (SVA) are uncommon congenital lesions. The clinical presentations vary from asymptomatic to progressive heart failure following rupture of the aneurysm into an adjacent cardiac chamber. Retrograde aortogram is the diagnostic tool of choice preoperatively. Recent studies have demonstrated that the SVA can be accurately diagnosed using transthoracic two-dimensional, and color Doppler flow mapping, even for surgical preparation without cardiac catheterization. We report our 5-year experience of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in the evaluation of SVA.

METHODS

Eleven adult patients with SVA with or without rupture were studied using both TTE and TEE. All of the diagnoses were subsequently comfirmed by either cardiac catheterization or surgical findings.

RESULTS

Aneurysms originated in the right coronary sinus (n = 9) and noncoronary sinus (n = 2); they ruptured into the right ventricle in 5 patients and the right atrium in 5 patients. An unruptured right SVA was noted in 1 patient. Both TTE and TEE could identify the site of the aneurysm, rupture sites, and the receiving chamber equally well. Co-existent cardiac lesions included 11 cases of valvular aortic regurgitation (mild in 7, moderate in 2 and severe in 2). Two cases of perimembranous type ventricular septal defect (VSD) and 6 cases of supracristal type VSD (including 1 case of tetraology of Fallot, 3 supracristal, 1 muscular and 1 subaortic) were noted. Three cases were complicated with valvular vegetations (1 aortic valve, 1 aortic and tricuspid valve and 1 aortic and pulmonic valve). One patient had patent ductus arteriosus and 2 patients had pulmonic valvular stenosis.

CONCLUSIONS

TEE provides clearer definition for the detailed anatomy of the ruptured sac and co-existent cardiac lesions than TTE through high resolution and closer approach. We conclude that TEE is a powerful complementary diagnostic tool in the evaluation of patients with SVA. TEE also provides additionally useful information for guiding the surgical approach and for assessing the operative results even without cardiac catheterization.

Complement activation in circulation and central nervous system after rituximab (anti-CD20) treatment of B-cell lymphoma

Rituximab (IDEC-C2B8, Mabthera, Rituxan), a chimeric monoclonal antibody against the B-cell specific CD20-antigen, has been demonstrated to be effective in the treatment of non-Hodgkin's B-cell lymphoma (B-NHL). Previous in vitro studies have shown that direct complement-dependent cytotoxicity (CDC), ADCC and apoptosis are important in the rituximab-induced killing of lymphoma cells. It is, however, unknown whether rituximab penetrates the blood-brain barrier. Therefore, we studied rituximab levels and complement (C) activation in blood and cerebrospinal fluid (CSF) following intravenous rituximab therapy in a patient with relapsing non-Hodgkin's lymphoma with central nervous system (CNS) involvement. Longitudinal samples from blood and CSF were taken at 13 time-points during the treatment period. The results show that the C cascade becomes activated in blood during the first mAb infusion (C3a-desArg concentration rose from 55 to 138 microg/ml during the first 2 hours). After the first infusion the proportions of lymphocytes positive for the CD19- and CD20-antigens in the peripheral blood were reduced from 41% and 35%, respectively, to a level of 2% (for both). In CSF the rituximab concentration increased after successive infusions, but remained below 0.55 microg/ml (compared to a Cmax of 400 microg/ml in peripheral blood). Although a minor and delayed C activation response was seen in the CSF the treatment did not clear CD20-positive cells away from the CNS. Thus, it appears that an intact blood-brain barrier restricts the entry of rituximab into the CNS. Possible options to circumvent this would be dose escalation or intrathecal rituximab treatment.

Lower prolactin bioactivity in unmedicated schizophrenic patients

In previous work, prolactin (PRL) abnormalities of a lower bioassay (BA) to radioimmunoassay (RIA) ratio were found in schizophrenic patients. This line of research was extended in seven male patients with schizophrenia who were neuroleptic-free; seven male control subjects were also studied. PRL values were assessed by RIA and Nb(2) BA techniques. The schizophrenic group had a significantly lower PRL BA as compared to normal controls and a lower PRL ratio of BA/RIA. The lower ratio is consistent with an earlier finding and suggests that schizophrenic patients have different molecular forms of PRL than control subjects. This difference could be due to a disordered tuberoinfundibular dopamine system or the long-term effects of neuroleptic medications.

Solution structure of the dimeric cytoplasmic domain of syndecan-4

The syndecans, transmembrane proteoglycans which are involved in the organization of cytoskeleton and/or actin microfilaments, have important roles as cell surface receptors during cell-cell and/or cell-matrix interactions. Since previous studies indicate that the function of the syndecan-4 cytoplasmic domain is dependent on its oligomeric status, the conformation of the syndecan-4 cytoplasmic domain itself is important in the understanding of its biological roles. Gel filtration results show that the syndecan-4 cytoplasmic domain (4L) itself forms a dimer stabilized by ionic interactions between peptides at physiological pH. Commensurately, the NMR structures demonstrate that syndecan-4L is a compact intertwined dimer with a symmetric clamp shape in the central variable V region with a root-mean-square deviation between backbone atom coordinates of 0.95 A for residues Leu(186)-Ala(195). The molecular surface of the 4L dimer is highly positively charged. In addition, no intersubunit NOEs in membrane proximal amino acid resides (C1 region) have been observed, demonstrating that the C1 region is mostly unstructured in the syndecan-4L dimer. Interestingly, two parallel strands of 4L form a cavity in the center of the dimeric twist similar to our previously reported 4V structure. The overall topology of the central variable region within the 4L structure is very similar to that of 4V complexed with the phosphatidylinositol 4,5-bisphosphate; however, the intersubunit interaction mode is affected by the presence of C1 and C2 regions. Therefore, we propose that although the 4V region in the full cytoplasmic domain has a tendency for strong peptide--peptide interaction, it may not be enough to overcome the repulsion of the C1 regions of syndecan-4L.

Multiple ligand interaction of alpha-synuclein produced various forms of protein aggregates in the presence of Abeta25-35, copper, and eosin

Various protein aggregates of alpha-synuclein developed by way of the common protein self-oligomerization in the presence of Abeta25-35, copper, and eosin were examined. All the aggregates exhibited congo red birefringence although the actual amounts of the aggregates were varied as determined by thioflavin T binding fluorescence. When their morphologies were analyzed in relation to in vitro cytotoxicity, the smallest granular aggregates obtained with copper exhibited the highest cytotoxicity, while the fibrous structures by eosin did not affect the cell.

4-Hydroxytamoxifen binds to and deactivates the estrogen-related receptor gamma

The estrogen-related receptors (ERR alpha, ERR beta, and ERR gamma) form a family of orphan nuclear receptors that share significant amino acid identity with the estrogen receptors, but for which physiologic roles remain largely unknown. By using a peptide sensor assay, we have identified the stilbenes diethylstilbestrol (DES), tamoxifen (TAM), and 4-hydroxytamoxifen (4-OHT) as high-affinity ligands for ERR gamma. In direct binding assays, 4-OHT had a K(d) value of 35 nM, and both DES and TAM displaced radiolabeled 4-OHT with K(i) values of 870 nM. In cell-based assays, 4-OHT binding caused a dissociation of the complex between ERR gamma and the steroid receptor coactivator-1, and led to an inhibition of the constitutive transcriptional activity of ERR gamma. ERR alpha did not bind 4-OHT, but replacing a single amino acid predicted to be in the ERR alpha ligand-binding pocket with the corresponding ERR gamma residue allowed high-affinity 4-OHT binding. These results demonstrate the existence of high-affinity ligands for the ERR family of orphan receptors, and identify 4-OHT as a molecule that can regulate the transcriptional activity of ERR gamma.

A novel cyclooxygenase-inhibitory stilbenolignan from the seeds of Aiphanes aculeata

[structure: see text] Aiphanol (1), a novel stilbenolignan, along with isorhapontigenin (2), piceatannol (3), and luteolin, were isolated by bioassay-guided fractionation from the seeds of Aiphanes aculeata Willd. (Arecaceae). The structure of compound 1 was elucidated by spectroscopic methods. Compound 1 is based on an unprecedented stilbenolignan skeleton in which a stilbene moiety is linked with a phenylpropane unit through a dioxane bridge. Compounds 1 and 2 exhibited significant inhibitory activities against cyclooxygenases-1 and -2.

Viral interferon regulatory factor 1 of Kaposi's sarcoma-associated herpesvirus binds to p53 and represses p53-dependent transcription and apoptosis

Kaposi's sarcoma-associated herpesvirus (KSHV) is related to the development of Kaposi's sarcoma. Open reading frame K9 of KSHV encodes viral interferon regulatory factor 1 (vIRF1), which functions as a repressor of interferon- and IRF1-mediated signal transduction. In addition, vIRF1 acts as an oncogene to induce cellular transformation. Here we show that vIRF1 directly associates with the tumor suppressor p53 and represses its functions. The vIRF1 interaction domains of p53 are the DNA binding domain (amino acids [aa] 100 to 300) and the tetramerization domain (aa 300 to 393). p53 interacts with the central region (aa 152 to 360) of vIRF1. vIRF1 suppresses p53-dependent transcription and deregulates its apoptotic activity. These results suggest that vIRF1 may regulate cellular function by inhibiting p53.

Is prosthetic renal artery reconstruction a durable procedure? An analysis of 489 bypass grafts

OBJECTIVE

Renal artery stenosis has been classically addressed with saphenous vein bypass graft or transaortic endarterectomy performed either primarily or in combination with an aortic procedure. In this series, we report the outcome of our 12-year experience with renal artery reconstruction using prosthetic conduit.

METHODS

Patients undergoing renal artery bypass grafting from 1987 to 1999 were identified. Demographics, indications, concurrent operations, complications, and patency were analyzed. Patients underwent postoperative duplex scan with subsequent ultrasound scans at 6-month intervals.

RESULTS

There were 489 procedures performed in 414 patients with indications: high-grade renal artery stenosis in combination with abdominal aortic aneurysm repair or symptomatic aortoiliac occlusive disease (309 [63%]), renovascular hypertension (118 [24%]), and renal salvage (20 [4%]). Indications for the remainder included trauma, renal artery aneurysm, or an infected aortic graft. Inflow was aorta or aortic graft in 95% of patients with the remainder taken from the iliac or visceral vessels. The retroperitoneal approach was used in 97.8%. Nonfatal complications occurred in 11.4% with a 1.4% early and 4.8% late occlusion rate. Renal function worsened in 3.1% of all patients. Secondary patency at 1 and 5 years was 98% and 96%, respectively.

CONCLUSION

Renal artery reconstruction with prosthetic conduit has an acceptable and durable result whether used for primary renal artery reconstruction or concomitant reconstruction with aortic procedures.

A brief report on the Penn Inventory for posttraumatic stress disorder

In this report we provide normative data for the Penn Inventory for posttraumatic stress disorder for men and women who were referred to a specialist outpatient clinic following a range of traumatic events. Data are provided from clinical assessment of 80 people. There was no significant difference between male and female scores. Using the Clinician Administered PTSD Scale to ascertain diagnostic status and Hammarberg's cut-off criterion of 35, the Penn Inventory showed a sensitivity of .90 for male participants and .89 for female participants and a specificity of .55 for male participants and .67 for female participants. The Penn Inventory correlated highly with other measures of psychological distress. We discuss that the Penn Inventory may be best used as a screening instrument or measure of change of general mental well-being after trauma, rather than a diagnostic tool for specific traumatic stress symptoms.

Automatic skeleton generation for visualizing 3D, time-dependent fluid flows: application to the virtual aneurysm

Intracranial aneurysms are the primary cause of non-traumatic subarachnoid hemorrhage. Difficulties in identifying which aneurysms will grow and rupture arise because the physicians lack important anatomic and hemodynamic information. Through simulation, this data can be captured, but visualization of large simulated data sets becomes cumbersome, often resulting in visual clutter and ambiguity. To address these visualization issues, we developed an algorithm that extracts a skeleton of the patterns in 3D, time-dependent blood flow. The algorithm decomposes the blood flow into "bare-bones" components that can be visualized individually or superimposed together to formulate an understanding of the flow patterns in the aneurysm.