Retrospective Exploration of Botulinum Toxin Injection for Pharyngoesophageal Segment Dysfunction Post-laryngectomy.

Objective: To assess our institution's experience with botulinum toxin A injection management of pharyngoesophageal (PE) segment dysfunction after laryngectomy in tracheoesophageal voice and swallowing restoration. Study Design: A retrospective review of 43 patients who had Botox as treatment for PE dysfunction. Setting: Tertiary academic center with fellowship-trained otolaryngologists. Methods: Pre- and post-injection outcomes were evaluated using chart review, and the severity of symptoms was recorded based on the subjective assessment by the patient, speech language pathologists, and the treating surgeon. Results: Forty-three patients were treated for PE dysfunction with botulinum toxin A injection. Most patients were male (n = 35, 81.4%), underwent primary cricopharnygeal myotomy (n = 36, 83.7%), and 37 (86%) had both dysphagia and speech concerns. Our injection methods included percutaneous injection by videofluoroscopy (n = 19, 44.2%), transnasal esophagoscopy (17, 40.5%), electromyography (n = 3, 7%), ultrasound (n = 1, 2.3%), or in the operating room (n = 3,7%). We found that 37 (86%) patients had subjective improvement in their symptoms, with 16 (38.1%) improving in both swallow and voice. There were no significant complications, or subjective difference in speech and swallowing outcomes by method of injection. Conclusion: Botulinum toxin A injection appears to be safe and effective for treating difficulty with speech and swallowing due to PE dysfunction after laryngectomy. Institutions should develop standard protocols for treatment and assessment.

Pharyngeal Mucosal Margin Vessel Counts Predict Pharyngocutaneous Fistula in Salvage Laryngectomy.

OBJECTIVE: We evaluated vessel counts in the pharyngeal mucosal margins of patients who underwent salvage laryngectomy to establish whether mucosal vascularity might predict fistula risk. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary Medical Center. METHODS: Patients who underwent salvage total laryngectomy at our institution between 1999 and 2015 were identified. Pharyngeal mucosal margins from laryngectomy specimens were evaluated histologically for each patient, and vessel counts were performed on 5 ×10 images. The primary outcome measure was fistula within 30 days of surgery and mean vessel counts were assessed as the principle explanatory variable. RESULTS: Seventy patients were included and 40% developed a postoperative fistula. There was a large difference in the mean vessel count in patients who did develop fistula (48.6 vessels/×10 field) compared to those who did not (34.7 vessels/×10 field). A receiver operative characteristic curve found that a cutoff value of 33.9 vessels/×10 field provided a sensitivity of 75% and specificity of 62% to predict the likelihood of fistula occurrence (area under the curve = 0.71, 95% confidence interval [CI]: 0.59-0.83). In a binary logistic regression, patients with vessel counts greater than 33.9 had a 5-fold increased risk of developing fistula (95% CI: 1.8-16.45). Histologically, vessels in the pharyngeal mucosa of patients who developed fistulas were more disorganized. CONCLUSION: After salvage laryngectomy, patients with higher mean mucosal margin vessel counts are at increased risk of fistula. The mechanism is unknown, but the disorganization of the vasculature may contribute to poor wound healing. Vessel counting may allow for fistula risk stratification and guide postoperative care.

Role of the otologist/neurotologist in managing auricular and periauricular cutaneous malignancies: A 10-year otologic oncology experience.

Objective: Auricular/periauricular cutaneous malignancies can be challenging to manage surgically due to the complex anatomy of the region. Otologists/neurotologists have unique skillsets that are well-suited to surgically treat these patients. We aim to highlight the role of otologists and neurotologists in providing surgical care of patients with auricular and periauricular malignancies by describing the experience of a single fellowship-trained neurotologist over a 10-year period. Methods: Retrospective chart review of 387 patients with auricular and periauricular malignancy treated by a single neurotologist between 2012 and 2022 was completed. Tumor histology and procedures performed for each patient were extracted. Additional data was collected for a subset of 84 patients with complex cases requiring selective neck dissection, parotidectomy, lateral temporal bone resection, regional advancement or rotational flap reconstruction, and/or free tissue transfer reconstruction. Results: Within the series of 387 patients, squamous cell carcinoma was the most common histology (42.6%, n = 165), followed by basal cell carcinoma (40.8%, n = 158), and melanoma (9.8%, n = 38). Common surgical procedures included wide local excision (61.8%, n = 239), partial/sub-total auriculectomy 18.3% (n = 71), or total auriculectomy 5.2% (n = 20). Within the 84-patient subset, median age at diagnosis was 71.9 years. Dermatologists provided most patient referrals (50.0%, n = 42). Most common tumor locations included: auricular (58.3%, n = 49), pre-auricular (21.4%, n = 18), and parotid (27.4%, n = 23). Revision surgery occurred in 22.6% of cases (n = 19), of which 26.3% (n = 5) for positive margins and 31.6% (n = 6) for recurrence. Mean follow-up was 22.8 months. Disease-specific 5-year survival was 91%. Conclusions: We demonstrate the feasibility of an otologist/neurotologist incorporating the surgical management of auricular and periauricular malignancies into their practice. Level of Evidence: 4.

Readiness of Medical Students to Care for Diverse Patients: A Validated Assessment of Cross-Cultural Preparedness, Skills, and Curriculum.

Introduction: Effective cross-cultural care is foundational for mitigating health inequities and providing high-quality care to diverse populations. However, medical school teaching practices vary widely, and learners have limited opportunities to develop these critical skills. To understand the current state of cross-cultural education and to identify potential opportunities for improvement, we disseminated a validated survey instrument among medical students at a single institution. Methods: Learners across 4 years of medical school participated in the cross-cultural care assessment, using a tool previously validated with resident physicians and modified for medical students. The survey assessed medical student perspectives on (1) preparedness, (2) skillfulness, and (3) educational curriculum and learning environment. Cross-sectional data were analyzed by class year, comparing trends between school years. Results: Of 700 possible survey responses, we received 260 (37% response rate). Fourth-year students had significantly higher scores than first-year students (p<0.05) for 7 of 12 preparedness items and 4 of 9 skillfulness items. Less than 50% of students indicated readiness to deliver cross-cultural care by their fourth year in 9 of 12 preparedness items and 6 of 9 skillfulness items. Respondents identified inadequate cross-cultural education as the primary barrier. Discussion: Medical students reported a lack of readiness to provide cross-cultural care, with self-assessed deficiencies persisting through the fourth year of medical school. Medical educators can use data from the cross-cultural care survey to longitudinally assess students and enhance curricular exposures where deficiencies exist. Optimizing cross-cultural education has the potential to improve the learning environment and overall patient care.

Normal-mode oscillations for the circular and dipolar states of a filled hexagonal magnetic dipole cluster.

We analyze the rotational dynamics of six magnetic dipoles of identical strength at the vertices of a regular hexagon with a variable-strength dipole in the center. The seven dipoles spin freely about fixed axes that are perpendicular to the plane of the hexagon, with their dipole moments directed parallel to the plane. Equilibrium dipole orientations are calculated as a function of the relative strength of the central dipole. Small-amplitude perturbations about these equilibrium states are calculated in the absence of friction and are compared with analytical results in the limit of zero and infinite central dipole strength. Normal modes and frequencies are presented. Bifurcations are seen at two critical values of the central dipole strength, with bistability between these values.

Verrucous Carcinoma of the Foot: A Retrospective Study of 19 Cases and Analysis of Prognostic Factors Influencing Recurrence.

This study sought to evaluate a cohort of patients with verrucous carcinoma of the foot with special focus on 5 cases of locally recurrent tumors despite negative margins. Nineteen cases of verrucous carcinoma of the foot were identified through the University of Michigan (Ann Arbor, Michigan) pathology database from 1995 to 2019 and were included in demographic and clinical presentation analyses. Sixteen cases were treated at the University of Michigan and are included in the treatment analyses. A review of medical records was conducted to characterize clinical, surgical, and pathologic features. Recurrent cases were found to have a predilection for nonglabrous skin of the foot and great toe. Otherwise, there was little to differentiate outcomes between recurrent and nonrecurrent groups based on demographic, clinical, surgical, or histopathologic data. Recurrent tumors regrew locally and were not associated with histologic progression to conventional squamous cell carcinoma. Verrucous carcinoma of the nonglabrous surface of the foot should have a higher suspicion for possible local recurrence. Recurrence occurs within months of treatment, deserves early biopsy, and warrants aggressive re-treatment. Future directions should include greater examination of pathologic features and genetic markers to improve management of verrucous carcinoma of the foot.

Effects of Moringa Extract on Aminoglycoside-Induced Hair Cell Death and Organ of Corti Damage.

HYPOTHESIS: Moringa extract, a naturally occurring anti-oxidant, protects against aminoglycoside-induced hair cell death and hearing loss within the organ of Corti. BACKGROUND: Reactive oxygen species (ROS) arise primarily in the mitochondria and have been implicated in aminoglycoside-induced ototoxicity. Mitochondrial dysfunction results in loss of membrane potential, release of caspases, and cell apoptosis. Moringa extract has not previously been examined as a protective agent for aminoglycoside-induced ototoxicity. METHODS: Putative otoprotective effects of moringa extract were investigated in an organotypic model using murine organ of Corti explants subjected to gentamicin-induced ototoxicity. Assays evaluated hair cell loss, cytochrome oxidase expression, mitochondrial membrane potential integrity, and caspase activity. RESULTS: In vitro application of moringa conferred significant protection from gentamicin-induced hair cell loss at dosages from 25 to 300 µg/mL, with dosages above 100 µg/mL conferring near complete protection. Assays demonstrated moringa extract suppression of ROS, preservation of cytochrome oxidase activity, and reduction in caspase production. CONCLUSION: Moringa extract demonstrated potent antioxidant properties with significant protection against gentamicin ototoxicity in cochlear explants.

The Clarion Call of the COVID-19 Pandemic: How Medical Education Can Mitigate Racial and Ethnic Disparities.

Public health crises palpably demonstrate how social determinants of health have led to disparate health outcomes. The staggering mortality rates among African Americans, Native Americans, and Latinx Americans during the COVID-19 pandemic have revealed how recalcitrant structural inequities can exacerbate disparities and render not just individuals but whole communities acutely vulnerable. While medical curricula that educate students about disparities are vital in rousing awareness, it is experience that is most likely to instill passion for change. The authors first consider the roots of health care disparities in relation to the current pandemic. Then, they examine the importance of salient learning experiences that may inspire a commitment to championing social justice. Experiences in diverse communities can imbue medical students with a desire for lifelong learning and advocacy. The authors introduce a 3-pillar framework that consists of trust building, structural competency, and cultural humility. They discuss how these pillars should underpin educational efforts to improve social determinants of health. Effecting systemic change requires passion and resolve; therefore, perseverance in such efforts is predicated on learners caring about the structural inequities in housing, education, economic stability, and neighborhoods-all of which influence the health of individuals and communities.

Sudden Sensorineural Hearing Loss: A Diagnostic and Therapeutic Emergency.

The family physician's role in recognizing and managing sudden sensorineural hearing loss (SSNHL) is crucial. A recently updated otolaryngologic clinical practice guideline has been released for this emergency syndrome, but dissemination is limited to a specialty journal. As a result, the guidelines may not be widely available in the primary care setting where patients often present. We provide this focused review to clarify and disseminate SSNHL guidelines for the frontline family physician.

Head and Neck Reconstruction in the Vessel Depleted Neck.

Microvascular free tissue transfer has revolutionized reconstruction and subsequently functional outcomes in the head and neck, but requires suitable recipient vessels for successful results. Recipient vessels can be significantly compromised by prior surgery, radiation therapy, or existing and/or underlying vascular disease in the neck. When further microvascular reconstruction is required in the vessel-depleted neck, identification of appropriate vessels for anastomosis can be difficult and can present complex decisions for the surgeon as well as the patient. In this article, we review the available literature on the vessel depleted neck and the possible vessel options. We present critical strategies for preoperative treatment planning and vessel selection in these patients. We also discuss the benefits and limitations of arterial and venous options while commenting on our unique institution's experiences. The external carotid branches as well as the available subclavian artery branches are presented in detail. The venous anatomy is also described, with particular focus on the accompanying veins and cephalic vein. We provide guidance on the selection and modification of free flaps to achieve the greatest function and cosmetic outcomes in the vessel depleted neck. Our collection of advanced management techniques will provide surgeons with more options to manage the complexity of the vessel depleted neck, and to further help patients understand the risk and benefits of these selections.

Airway Management for Endoscopic Laryngotracheal Stenosis Surgery During COVID-19.

The novel coronavirus disease 2019 (COVID-19) pandemic presents unique challenges for surgical management of laryngotracheal stenosis. High viral concentrations in the upper aerodigestive tract, the ability of the virus to be transmitted by asymptomatic carriers and through aerosols, and the need for open airway access during laryngotracheal surgery create a high-risk situation for airway surgeons, anesthesiologists, and operating room personnel. While some surgical cases of laryngotracheal stenosis may be deferred, patients with significant airway obstruction or progressing symptoms often require urgent surgical intervention. We present best practices from our institutional experience for surgical management of laryngotracheal stenosis during this pandemic, including preoperative triage, intraoperative airway management, and personal protective measures.

Analgesic efficacy of the cyclooxygenase-inhibiting nitric oxide donor AZD3582 in postoperative dental pain: Comparison with naproxen and rofecoxib in two randomized, double-blind, placebo-controlled studies.

OBJECTIVE: This study assessed the analgesic efficacy of single doses of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propanoate (AZD3582) in acute postoperative dental pain after the removal of an impacted mandibular third molar (ie, wisdom tooth). METHODS: Two randomized, placebo-controlled, double-blind studies were performed. In a dose-finding study, 242 patients were randomized to AZD3582 375, 750, 1500, or 2250 mg (n = 41, 37, 42, and 41, respectively); naproxen 500 mg (n = 39); or placebo (n = 42). In a comparator study, 282 patients were randomized to AZD3582 500 mg (n = 78) or 750 mg (n = 83), rofecoxib 50 mg (n = 80), or placebo (n = 41). Primary outcomes included time to rescue medication, time to pain relief, and mean pain intensity difference (MPID), as well as safety profile. Pain was rated on a visual analog scale. RESULTS: In the dose-finding study, 52% (126/242) were women; the mean (SD) age was 25.1 (4) years, mean weight was 69.0 kg, and the mean (SD) body mass index (BMI) was 23.7 (3) kg/m2. In the comparator study, 58% (164/282) were women; the mean (SD) age was 27 (6.4) years, mean weight was 71 kg, and mean (SD) BMI was 24.2 (3) kg/m2. In the dose-finding study, the AZD3582 750-, 1500-, and 2250-mg groups were superior to placebo in the primary variables "time to rescue medication (0-8 hours)" (hazard ratios [HRs] [95% CIs], 0.17 [0.07-0.42], P < 0.003; 0.23 [0.11-0.50], P < 0.001; and 0.15 [0.06-0.36], P < 0.001, respectively), "time to meaningful pain relief" (HRs [95% CIs], 3.42 [1.87-6.25], P < 0.003; 2.49 [1.37-4.50], P < 0.003; and 3.07 [1.70-5.55], P < 0.001, respectively), and MPID (analysis of covariance [ANCOVA] least squares mean [LSM] differences [95% CIs], 25.8 [17.3-34.4], P < 0.003; 20.4 [12.1-28.7], P < 0.003; and 29.3 [20.9-37.6], P < 0.001, respectively). AZD3582 and naproxen did not show any statistically significant differences for the 3 primary variables, except that naproxen was superior to the AZD3582 375-mg dose for the variables time to meaningful pain relief (HR difference, 0.48 [95% CI, 0.29-0.78], P < 0.004) and MPID (difference in ANCOVA LSM, -10.2, [95% CI, -18.2 to -2.2], P < 0.012). The median times to meaningful pain relief were 115 minutes for AZD3582 375 mg, 66 minutes for 750 mg, 85 minutes for 1500 mg, 81 minutes for 2250 mg, and 162 minutes for placebo (P = NS, P = 0.003, P < 0.003, and P < 0.001, respectively). The median time to first rescue medication was 144 minutes for placebo, and <50% of the subjects on any of the AZD3582 doses or naproxen took rescue medication within 8 hours after dosing. In the comparator study, AZD3582 750 mg was superior to placebo in "time to rescue medication (0-24 hours)" (HR [95% CI], 0.4 [0.3-0.6], P < 0.001), "time to confirmed perceptible pain relief" (2.1 [1.1-3.8], P = 0.02), and MPID (11.9 [4.2-19.5], P = 0.002). However, inferiority of AZD3582 to rofecoxib for MPID could not be excluded (tolerance limit of 10 mm; P = NS for noninferiority testing). The median times to confirmed perceptible pain relief were 45 minutes for AZD3582 500 mg, 40 minutes for 750 mg, and 37 minutes for rofecoxib. The median times to first rescue medication were 218 minutes for AZD3582 500 mg, 365 minutes for 750 mg, 635 minutes for rofecoxib, and 90 minutes for placebo. Overall, AZD3582 was well tolerated. However, an effect on orthostatic blood pressure could not be excluded because there seemed to be more subjects with dizziness and orthostatic blood pressure reduction who were administered AZD3582 > or =750 mg. The proportions of patients with vertigo and decreased orthostatic blood pressure each group were as follows: AZD3582 500 mg, 6%; AZD3582 750 mg, 12%; rofecoxib, 3%; and placebo, 5%. CONCLUSIONS: AZD3582 750 mg had similar analgesic efficacy as equimolar doses of naproxen, but noninferiority to rofecoxib was not demonstrated.

Assessment and modeling of the toxicity of organic chemicals to Chlorella vulgaris: development of a novel database.

This study reports a database of toxicity values for 91 compounds assessed in a novel, rapid, and economical 15 min algal toxicity test. The toxicity data were measured using the unicellular green alga Chlorella vulgaris in an assay that determined the disappearance of fluorescein diacetate. The chemicals tested covered a wide range of physicochemical properties and mechanisms of action. Quantitative activity-activity relationships with the toxicity of the chemicals to other species (Tetrahymena pyriformis, Vibrio fischeri, and Pimephales promelas) showed strong relationships, although some differences resulting from different protocols were established. Quantitative structure-activity relationships (QSARs) were determined using linear [multiple linear regression (MLR)] and nonlinear [k-nearest neighbors (KNN)] methods. Three descriptors, accounting for hydrophobicity, electrophilicity, and a function of molecular size corrected for the presence of heteroatoms, were found to be important to model toxicity. The predictivity of MLR was compared to KNN using leave-one-out cross-validation and the simulation of an external test set. MLR demonstrated greater stability in validation. The results of this study showed that method selection in QSAR is task-dependent and it is inappropriate to resort to more complicated but less transparent methods, unless there are clear indications (e.g., inability of MLR to deal with the data set) for the need of such methods.

QSAR analysis of the toxicity of aromatic compounds to Chlorella vulgaris in a novel short-term assay.

The use of alternative toxicity tests and computational prediction models is widely accepted to fill experimental data gaps and to prioritize chemicals for more expensive and time-consuming assessment. A novel short-term toxicity test using the alga Chlorella vulgaris was utilized in this study to produce acute aquatic toxicity data for 65 aromatic compounds. The compounds tested included phenols, anilines, nitrobenzenes, benzaldehydes and other poly-substituted benzenes. The toxicity data were employed in the development of quantitative structure-activity relationships (QSARs). Using multiple regression (MLR) and partial least squares (PLS) analyses, statistically significant, transparent and interpretable QSARs were developed using a small number of physicochemical descriptors. A two-descriptor model was developed using MLR (log(1/EC50)=0.73 log Kow-0.59 Elumo-1.91; n=65, r2=0.84, r2CV=0.82, s=0.43) and a four-descriptor model using PLS (log(1/EC50)=0.40 log Kow-0.23 Elumo+9.84 Amax+0.20 0chiv-5.40; n=65, r2=0.86, q2=0.84, RMSEE=0.40). The latter model was obtained by stepwise elimination of variables from a set of 102 calculated descriptors. Both models were validated successfully by simulating external prediction through the use of complementary subsets. The two factors, which were identified as being critical for the acute algal toxicity of this set of compounds were hydrophobicity and electrophilicity.

Effect of ball size on player reaction and racket acceleration during the tennis volley.

The purpose of this study was to examine the effect of ball size on reaction time (from ball projection to initial racket movement), movement time (from ball projection to ball-racket impact), mean rectified acceleration and vibration frequency of the racket during the impact phase (100 ms duration after ball-racket impact) of the tennis volley. Twenty-nine beginning to intermediate level tennis players performed volleys under 18 experimental conditions including variations in lateral contact location (forehand and backhand), ball type (Penn oversize, Wilson oversize, regular size), and ball speed (fast, medium, slow). A ball machine was shielded so that the subjects could not predict the ball trajectory before it was released from the machine. Outcome measures were determined using a miniature uni-axial accelerometer and a Photogate timing device. ANOVA with repeated measures and Tukey's post hoc tests were used in statistical analyses (p < .025). The reaction times for the fast speed were significantly shorter than the corresponding times for the slow speed and the reaction times for the forehand volley were significantly shorter than that of the backhand volley. The significant interaction in movement time between ball speed and ball type indicates that the benefits of the larger ball (to slow the game down) increase as the ball speed increases. No significant effect of ball type or ball speed, or interactions were found on mean rectified acceleration and vibration frequency. These results suggest that oversized balls would not cause an increased load to the hitting arm while executing a tennis volley.

Efficacy and Safety of Remacemide versus Carbamazepine in Newly Diagnosed Epilepsy: Comparison by Sequential Analysis.

An international trial comparing remacemide hydrochloride with carbamazepine was undertaken in newly diagnosed epilepsy using a novel double-blind, parallel group, double triangular sequential design. Patients with two or more partial or generalized tonic-clonic seizures in the previous year were randomized to 600 mg daily of remacemide or carbamazepine. Subsequent dosage adjustments were allowed while maintaining the blind. The trial completed 20 months after initiation following the second interim analysis. Efficacy data on 449 patients showed carbamazepine to be significantly more effective than remacemide in preventing seizure recurrence (P = 0.003). Median time to first seizure after titration, the primary endpoint, was 112 days for remacemide and 306 days with carbamazepine. Time to second, third, and fourth seizures after randomization all significantly favored carbamazepine. Remacemide was shown unequivocally to be inferior to carbamazepine in this patient population. This study also establishes carbamazepine as a proven treatment for use in subsequent active control comparative trials.

Rules of chemokine receptor association with T cell polarization in vivo.

Current concepts of chemokine receptor (CKR) association with Th1 and Th2 cell polarization and effector function have largely ignored the diverse nature of effector and memory T cells in vivo. Here, we systematically investigated the association of 11 CKRs, singly or in combination, with CD4 T cell polarization. We show that Th1, Th2, Th0, and nonpolarized T cells in blood and tissue can express any of the CKRs studied but that each CKR defines a characteristic pool of polarized and nonpolarized CD4 T cells. Certain combinations of CKRs define populations that are markedly enriched in major subsets of Th1 versus Th2 cells. For example, although Th0, Th1, and Th2 cells are each found among blood CD4 T cells coordinately expressing CXCR3 and CCR4, Th1 but not Th2 cells can be CXCR3(+)CCR4(-), and Th2 but only rare Th1 cells are CCR4(+)CXCR3(-). Contrary to recent reports, although CCR7(-) cells contain a higher frequency of polarized CD4 T cells, most Th1 and Th2 effector cells are CCR7(+) and thus may be capable of lymphoid organ homing. Interestingly, Th1-associated CKRs show little or no preference for Th1 cells except when they are coexpressed with CXCR3. We conclude that the combinatorial expression of CKRs, which allow tissue- and subset-dependent targeting of effector cells during chemotactic navigation, defines physiologically significant subsets of polarized and nonpolarized T cells.

CCR9-positive lymphocytes and thymus-expressed chemokine distinguish small bowel from colonic Crohn's disease.

BACKGROUND & AIMS: Thymus-expressed chemokine (TECK) or CCL25) is selectively expressed in the small bowel (SB), where lamina propria lymphocytes (LPL) and intraepithelial leukocyte expressing the cognate chemokine receptor CCR9 predominate. We characterize the role of TECK and CCR9-expresing lymphocytes in small intestinal Crohn's disease. METHODS: CCR9 expression on lymphocytes from lamina propria, mesenteric lymph node, and peripheral blood was analyzed by flow cytometry and by Northern blotting for LPL. TECK expression was analyzed in inflamed SB and colon by reverse-transcription polymerase chain reaction and immunohistochemistry. RESULTS: The fraction of CCR9(+) T cells in inflamed SB was significantly lower than in uninvolved SB mucosa. In contrast, in peripheral blood lymphocytes, CCR9(+) lymphocytes were markedly elevated in patients with small bowel Crohn's or celiac disease, but not in patients with purely colonic Crohn's. Also, TECK expression is altered in inflamed small bowel, being intensely expressed in a patchy distribution in crypt epithelial cells in proximity to lymphocytic infiltrates. TECK is not expressed in either normal or inflamed colon. CONCLUSIONS: In SB immune-mediated diseases, there is repartitioning of CCR9(+) lymphocytes between SB and blood and an altered pattern of TECK expression in SB Crohn's. The TECK/CCR9 ligand/receptor pair may play an important role in the pathogenesis of SB Crohn's disease.

Expression cloning of the STRL33/BONZO/TYMSTRligand reveals elements of CC, CXC, and CX3C chemokines.

STRL33/BONZO/TYMSTR is an orphan chemokine and HIV/SIV coreceptor receptor that is expressed on activated T lymphocytes. We describe an expression cloning strategy whereby we isolated a novel chemokine, which we name CXCL16. CXCL16 is an alpha (CXC) chemokine but also has characteristics of CC chemokines and a structure similar to fractalkine (neurotactin) in having a transmembrane region and a chemokine domain suspended by a mucin-like stalk. A recombinant version of CXCL16 fails to mediate chemotaxis to all known chemokine receptor transfectants tested but does mediate robust chemotaxis, high affinity binding, and calcium mobilization to Bonzo receptor transfectants, indicating that this is a unique receptor ligand interaction. In vitro polarized T cell subsets including Th1, Th2, and Tr1 cells express functional Bonzo, suggesting expression of this receptor in chronic inflammation, which we further verified by demonstration of CXCL16-mediated migration of tonsil-derived CD4(+) T lymphocytes. CXCL16 is expressed on the surface of APCs including subsets of CD19(+) B cells and CD14(+) monocyte/macrophages, and functional CXCL16 is also shed from macrophages. The combination of unique structural features of both Bonzo and CXCL16 suggest that this interaction may represent a new class of ligands for this receptor family. Additionally, this chemokine might play a unique dual role of attracting activated lymphocyte subsets during inflammation as well as facilitating immune responses via cell-cell contact.