Endovascular stent graft repair of abdominal aortic aneurysms after liver transplantation.

It is estimated that 1.7% of orthotopic liver transplant recipients will develop abdominal aortic aneurysms (AAAs) after transplantation. It has been observed that these aneurysms expand faster in transplant recipients; therefore, aggressive surveillance for AAAs in transplant recipients is required. Endovascular aneurysm repair is rapidly becoming the standard of care, especially in patients with previous abdominal surgery and other significant comorbidities. This article describes our experience with AAAs in orthotopic liver transplant recipients treated successfully by endovascular stent graft repair.     

NMR Microscopy of Single Neurons Using Spin Echo and Line Narrowed 2DFT Imaging

NMR microimages of single neural cells were acquired at 500 MHz using a conventional spin echo pulse sequence and a line-narrowing sequence that eliminates susceptibility effects. The data show that any contribution to the measured T₂ relaxation rate arising from diffusion in local field inhomogeneities using spin echo sequences at high fields and high spatial resolution is relatively small. We conclude that the measured T₂ difference between the nucleus and cytoplasm in these cells represents primarily a true T₂ relaxation effect arising from the interactions of water with macromolecules in the two compartments and does not result from microsusceptibility differences. These observations have implications regarding water compartmentation in single cells and the interpretation of the MR characteristics of tissues in vivo.     

Immunohistologic parameters in minimal morphologic change duodenal biopsies from patients with clinically suspected gluten-sensitive enteropathy.

Subclinical or latent cases of gluten-sensitive enteropathy (GSE) are difficult to diagnose, and serology-positive, histology-negative (minimal morphologic change) and serology-negative, histology-positive patients have been identified. Both, particularly the histology-negative group, require the correct diagnosis for proper management, especially because the concept of minimal histologic change GSE has escaped attention in standard textbooks. We assessed the numbers and distribution of intraepithelial T cells and their subsets with CD3, CD8, and CD4 immunostaining and examined for crypt hyperplasia with mitotic and Ki-67 proliferative indices with the aim of refining the criteria for the diagnosis of minimal change GSE. Duodenal biopsies from 46 clinically suspected cases of GSE tested for antigliadin, antiendomysium, and antitissue transglutaminase antibodies were divided into four groups: serology-positive, histology-positive (S+H+, n = 20); serology-positive, histology-negative (S+H-, n = 22), representing the minimal morphologic change group; serology-negative, histology-positive (S-H+, n = 4); and serology-negative, histology-negative (S-H-, n = 28), controls with histologically normal duodenal biopsies obtained for unrelated reasons. The numbers of CD3+ and CD8+ intraepithelial T cells (IETCs) were significantly higher in histology-positive biopsies with (mean, 40.3/100 and 39.3/100 enterocytes, respectively) and without positive serology (mean, 33.3/100 and 35/100 enterocytes, respectively) compared with all other groups (S+H-, mean, 26.5/100 and 24.3/100 enterocytes, respectively; S-H-, mean, 23.3/100 and 17.9/100 enterocytes, respectively). Values for Ki-67 index in crypt enterocytes were also significantly different between histology-positive and histology-negative groups (P = 0.000). The distribution of CD3+ and CD8+ IETCs was mostly even along the surface enterocytes in histology-positive cases compared with the controls, which showed an uneven distribution. The 2 parameters that significantly discriminated between minimal morphologic change GSE (S+H-) and controls (S-H-) were Ki-67 index (P = 0.007) and the distribution pattern of CD8+ IETCs (P = 0.049). CD4 IETC counts were generally low, with no significant difference between all groups. The few S-H+ cases seen most likely represented false-negative serology, because the assessed parameters of this group and S+H+ cases were indistinguishable.     

Chronic exposure to cold stress alters electrophysiological properties of locus coeruleus neurons recorded in vitro.

Chronic stress exposure can alter central noradrenergic function. Previously, we reported that in chronically cold-exposed rats the release of norepinephrine and electrophysiological activation of locus coeruleus (LC) neurons is enhanced in response to multiple excitatory stimuli without alterations in basal activity. In the present studies, we used in vitro intracellular recording techniques to explore the effect of chronic cold exposure on the basal and evoked electrophysiological properties of LC neurons in horizontal slices of the rat brainstem. Consistent with our findings from in vivo experiments, chronic cold exposure did not affect basal firing rate. Furthermore, gross morphology of LC neurons and spike waveform characteristics were similar in slices from control and previously cold-exposed rats. However, excitability in response to intracellular current injection and input resistance were larger in slices from previously cold-exposed rats. In addition, the accommodation of spike firing in response to sustained current injection was smaller and the period of postactivation inhibition appeared to be less in LC neurons from cold-exposed rats. These data demonstrate that the stress-evoked sensitization of LC neurons observed in vivo is at least in part maintained in the slice preparation and suggest that alterations in electrophysiological properties of LC neurons contribute to the chronic stress-induced sensitization of central noradrenergic function observed in vivo. Furthermore, the present data suggest that an alteration in autoinhibitory control of LC activity is involved in the chronic stress-induced alterations. The enhanced functional capacity of LC neurons following cold exposure of rats may represent a unique model to study the mechanisms underlying the alterations in central noradrenergic function observed in humans afflicted with mood and anxiety disorders.     

Total replacement of bladder and urethra by cecum and appendix in bladder exstrophy

The first case of total bladder and urethral replacement by cecoappendiceal unit was achieved in a five-year-old boy born with bladder exstrophy. Residual vesical and prostatic tissue was utilized to provide continence successfully.     

The results of microneurosurgery of the inferior alveolar and lingual nerve.

PURPOSE: The goal was to evaluate the experience of one surgical unit during a 5-year period in the evaluation and management of patients with injuries of the inferior alveolar and lingual nerve with particular reference to indications for and results of microneurosurgery. PATIENTS AND METHODS: This study includes all patients referred with a diagnosis of injury to the inferior alveolar or lingual nerve during 5-year period from January 1, 1994, to January 1, 1999. All patients were evaluated with Frey's hairs for touch and direction sense, 2-point discrimination, and hot and cold water and Minnesota thermal discs for temperature sensation. Patients who fulfilled certain specified criteria were offered microneurosurgery, and the results were evaluated for those who underwent microneurosurgery. RESULTS: The study consisted of 880 consecutive patients; 96 were thought to fulfill the criteria for microneurosurgery. Of these, 51 underwent microneurosurgical exploration and repair. In 5 patients, no injury could be detected at surgery, and no corrective surgery was performed other than decompression. In 26 patients, excision and direct anastomosis were performed, and in an additional 20 patients, nerve gap reconstruction was performed. In 16 of these 20 patients, reconstruction was performed with an autogenous vein graft, and in 2 patients, a Gore-Tex tube graft (W.L. Gore & Associates, Inc, Flagstaff, AZ) was used to bridge the nerve gap. In 2 patients, an autogenous nerve was used. Thirty-four of the repairs were made on the lingual nerve, and 17 were made on the inferior alveolar nerve. With the use of established criteria, 10 patients were considered to have had a good improvement in sensation, 18 patients were considered to have had some improvement in sensation, and 22 patients were considered to have had no improvement in sensation; 1 patient reported an increase in dysesthesia after surgery. The semiobjective assessment of patients did not always correspond with the patients' subjective evaluation. CONCLUSION: In a relatively small study in selected cases, microneurosurgery can provide a reasonable result in improving sensation in the inferior alveolar and lingual nerve. More than 50% of patients experienced some improvement in sensation, and dysesthesia did not develop after surgery in any patient who did not have it before surgery.     

Clinical significance of SNAP somnography test acoustic recording.

OBJECTIVE: To examine the clinical significance of acoustic data recorded by the SNAP home polysomnography system (SNAP Laboratories, Glenview, IL). STUDY DESIGN AND SETTING: Retrospective analysis of SNAP data from 59 patients undergoing evaluation for sleep apnea at the University of Nebraska Medical Center and an associated private practice in Omaha, NE. RESULTS: Snoring did not correlate with anthropometric variables such as body mass index and neck circumference. Statistical analysis showed no correlation between respiratory disturbance index and the maximum or average loudness of snoring. Average loudness was predictive of the presence of sleep apnea. Spectral analysis of snoring sonography found that the proportion of snoring events associated with a palatal source correlated strongly with the loudness of snoring. CONCLUSION: These data suggest that analysis of snoring has limited utility in the evaluation of the patient with sleep apnea but may be able to select patients who would benefit from palatal procedures to reduce snoring.