The petrolingual ligament: the anatomy and surgical exposure of the posterolateral landmark of the cavernous sinus

The petrolingual ligament is the posteroinferior attachment of the lateral wall of the cavernous sinus, where the internal carotid artery enters the cavernous sinus. The petrous segment of the internal carotid artery finishes and the cavernous segment begins at the superior margin of this ligament. The ligament is surgically important due to its identification as a landmark for dissection of the internal carotid artery during the approaches to posterolateral intracavernous and extracavernous lesions. It can be well exposed after mobilization of the gasserian ganglion, or after the trigeminal root and ganglion have been split along the junction of V2 and V3 (the transtrigeminal approach). The petrolingual ligament was studied in five cadaveric head specimens from ten sides. The size of the ligament was measured, and its anatomical, clinical and surgical importance is discussed.     

Performance of "standardized examinees" in a standardized-patient examination of clinical skills

PURPOSE: As a first step in testing the utility of using trained "standardized examinees" (SEs) as a quality-assurance measure for the scoring process in a standardized-patient (SP) examination, to test whether medical residents could simulate students in an SP examination and perform consistently to specified levels under test conditions. METHOD: Fourth-year students from the Baltimore-Washington Consortium for SPs participated in a National Board of Medical Examiners Prototype Examination of clinical skills consisting of twelve 15-minute student-patient encounters in 1994-95. For this examination, internal medicine residents were trained to act as ordinary candidates and to achieve target scores by performing to a set level on specific checklist items used by SPs for recording interviewing, physical-examination, and communication skills. The "strong SEs" were trained to score 80% correct on six of the examination's 12 cases (study cases), and the "weak SEs" were trained to score 40% correct on the same six cases. The strong and weak SEs' checklist scores on the study cases were compared through independent, two-tailed t-tests. When there was less than 85% agreement on specific checklist items in each case between the SE training and the SP recording, videotapes of the cases were reviewed; in such cases an SE's performance was the final score agreed upon after review. RESULTS: Seven SEs took the SP examination and were not detected by the SPs. There was a total of 84 discrepancies between predicted and recorded checklist scores across 659 checklist items in 40 encounters scored by the SPs. After correcting the discrepancies based on videotape review, the estimated actual mean score was 77.3% for the strong SEs and 44.0% for the weak SEs, and was higher for the strong SEs in each study case. The overall fidelity of the SEs to their training was estimated to be 97%, and the overall SP accuracy was estimated to be 91%. The videotape review revealed 47 training-scoring discrepancies, most in the area of communication skills. CONCLUSION: This study suggests that SEs can be trained to specific performance levels and may be an effective internal control for a high-stakes SP examination. They may also provide a mechanism for refining scoring checklists and for exploring the validity of SP examinations.     

Treatment effectiveness of patients with ocular tuberculosis at specialized sanatoria

The bloodflow is decreased in myopic eyes with dystrophic changes in the center and at the periphery, this decrease being in proportion with the severity of the changes. Our study was aimed at elucidating the contribution of the scleral and hemodynamic factors to the genesis of myopic and chorioretinal dystrophies. A total of 295 patients with progressive myopia were examined. The sagittal and frontal sizes of the eye were reliably increased and the rheographic coefficient lowered in complicated progressive myopia as against the condition without complications. The biomechanical factor plays the main role in the pathogenesis of dystrophies.     

Changes in the reactivity of the sensorimotor cortex resulting from the treatment of patients with depressive disorders

Changes in the mu-rhythm power in response to sound (non-specific reactivity, NR) and related with the actual and imaginary movement with the right and left hand in response to sound (specific reactivity, SR) were studied in 38 right-handed patients with subdepressive psychogenic (PD) and endogenous (ED) disorders before and after successful complex treatment (pharmacotherapy and acupuncture) in comparison with 23 healthy subjects. The successful treatment was found to be accompanied by a certain extent of normalization of the disturbed SR which was different in PD and ED. The more complete recovery of the normal reactions in PD was mainly accounted for by the relative decrease in the NR and increase in the SR. The ED treatment predominantly modified the SR. Substantial reorganization of interhemispheric relations during movements in the PD patients resulted in disappearance of the abnormal ipsilateral reactions and transition to the contralateral reactions of the sensorimotor cortex.     

Structure and expression of elongation factor Tu from Bacillus stearothermophilus

Over 80% of uropathogenic Escherichia coli express type 1 fimbriae. Expression is phase variable, and regulation of phase switching can differ between isolates. Previously, this was explained by differences in the expression of the fim recombinases, FimB and FimE. Our study of 50 uropathogenic E. coli isolates confirms variation in the regulation of type 1 fimbriae but, in many cases, the variation could be accounted for by sequence changes within and adjacent to the fim switch, rather than by differences in recombinase expression. This was demonstrated by moving the switch from the isolates into an isogenic background and comparing the switching behaviour with that of the original isolate. Isolates could be arranged into groups based on fim switch regulation and sequence similarity. In certain cases, the altered regulation was located to specific basepair changes within the fim switch. Sequence changes were found that had a marked effect on the activity of either FimB or FimE switching, while others affected FimB switching in only one direction. These results emphasize the value of using naturally selected sequence variation to further the understanding of gene regulation.     

Effects of carbon dioxide pneumoperitoneum, air pneumoperitoneum, and gasless laparoscopy on body weight and tumor growth

BACKGROUND: The oncologic consequences of intraperitoneal carbon dioxide (CO2) insufflation during the laparoscopic resection of cancer are under debate. The effect of other insufflating gases or gasless laparoscopy on cancer requires study. OBJECTIVE: To study body weight and tumor growth in rats after CO2 pneumoperitoneum, air pneumoperitoneum, and gasless laparoscopy. METHODS: On day 1, an 8-mg bolus of ROS-1 tumor was placed under the renal capsule of both kidneys in rats. In experiment A, rats had either CO2 insufflation (n=10) or a gasless laparoscopic bowel resection (n=10) on day 3 and were humanely killed after 7 days. In experiment B, rats had either a laparoscopic bowel resection with CO2 insufflation (n=11) or insufflation with air (n=11) on day 3 and were killed after 7 days. In both experiments, postoperative weight loss and tumor growth were measured, and the differences were tested with an analysis of covariance. RESULTS: Renal subcapsular tumor growth in the group having gasless laparoscopy was less than that in the group having CO2 pneumoperitoneum (P=.04). Postoperative weight loss in these groups showed no differences (P=.55). No differences in tumor growth or weight loss were found between rats having insufflation with CO2 and those having insufflation with air (P=.61 and P=.68, respectively). CONCLUSIONS: The restoration of body weight after a laparoscopic surgical procedure was similar with CO2, air, or gasless laparoscopy. Gasless laparoscopy was associated with less renal subcapsular tumor growth than was insufflation with CO2. Therefore, the application of gasless techniques in laparoscopic oncologic surgical treatment demands further study.     

Port-site metastases. Impact of local tissue trauma and gas leakage

OBJECTIVE: To determine whether selective 5-lipoxygenase (5-LO) inhibition decreases expression of adhesion molecules (beta2 integrins) on systemic neutrophils, decreases neutrophil infiltration in ischemic flap tissue, and improves flap survival. DESIGN: A randomized, controlled study of 91 adult female Hartley guinea pigs divided into 3 survival groups, 4 neutrophil assay groups, 1 sham group, and 1 control group. Ischemia of varying duration and reperfusion was induced in island flank skin flaps. The treated groups received zileuton, a 5-LO inhibitor, orally during flap ischemia. After reperfusion, systemic neutrophil receptor expression, neutrophil infiltration, and flap survival were measured. Surface receptor molecules on neutrophils from whole blood samples obtained via transcardiac puncture were analyzed using monoclonal antibodies and cell-associated fluorescence. Neutrophil infiltration into a distal 1 cm2 of flap tissue was assessed using myeloperoxidase antibodies. Flap survival was determined within 7 days of surgery. RESULTS: Untreated flaps with 10 hours of ischemia underwent total necrosis. Treated 2- and 10-hour ischemic flaps survived intact. A significant main effect of the drug treatment was detected using analysis of variance (P<.001). Neutrophil receptor detection in the untreated groups undergoing 2 and 10 hours of ischemia was significantly increased compared with that in the treated groups with the same ischemia times. Skin neutrophil infiltration was significantly decreased in the treated groups. CONCLUSIONS: Systemic administration of a 5-LO inhibitor is effective in reducing ischemia-reperfusion injury in flap tissue. Our data indicate that there is a significant reduction in neutrophil receptor expression with administration of 5-LO, reducing the priming of systemic neutrophils from circulating cytokines.     

Cat scratch disease: the rare role of Afipia felis

Since its isolation in 1988, Afipia felis has been associated with cat scratch disease (CSD) in only one report and its role in CSD has been questioned. We have cultured A. felis from a lymph node of a patient with CSD. 16S rRNA gene sequencing, DNA relatedness studies, fatty acid analysis, and PCR of the A. felis ferredoxin gene showed that the isolate is identical to the previously reported A. felis isolate. To determine the role of A. felis in CSD, PCR of the 16S rRNA gene followed by hybridizations with specific probes were performed with lymph node specimens from CSD patients. All 32 specimens tested positive for Bartonella henselae and negative for A. felis. We conclude that A. felis is a rare cause of CSD. Diagnostic tests not conducive to the identification of A. felis might cause the diagnosis of CSD due to A. felis to be missed.     

Axonal cytoskeletal pathology in aged and diabetic human sympathetic autonomic ganglia

Prevertebral sympathetic ganglia develop markedly enlarged argyrophilic neurites as a function of age, gender and diabetes. Immunolocalization studies demonstrate their preferential labeling with antisera to highly phosphorylated 200 kDa neurofilament (NF-H) epitopes, NPY, peripherin and synapsin I, but not to hypophosphorylated NF-M and NF-H or MAP-2. The immunophenotype of dystrophic neurites in conjunction with the results of histochemical and ultrastructural studies are consistent with the terminal axonal and/or synaptic origin of neuritic dystrophy in the sympathetic ganglia of aged and diabetic human subjects.