Effect of 3 Commercially Available Botulinum Toxin Neuromodulators on Facial Synkinesis: A Randomized Clinical Trial

Importance

Botulinum toxin neuromodulators are an important treatment for facial synkinesis. Whether a difference in efficacy exists among the 3 different botulinum neuromodulators used in treating this condition remains unknown.

Objective

To evaluate the effectiveness of 3 commercially available botulinum toxin neuromodulators in the treatment of facial synkinesis.

Design, Setting, and Participants

In this single-blind, 3-arm comparison randomized clinical trial, 28 patients at the Facial Nerve Center, University of Utah, Salt Lake City, were randomized to onabotulinumtoxinA, abobotulinumtoxinA, or incobotulinumtoxinA treatment. Each patient was given the Synkinesis Assessment Questionnaire (SAQ) to assess severity of synkinesis before treatment and 1, 2, and 4 weeks after treatment, and improvements were compared among the groups. Data were collected from July 3, 2012, to March 31, 2015.

Interventions

Botulinum toxin type A neuromodulator (onabotulinumtoxinA, abobotulinumtoxinA, or incobotulinumtoxinA) injected into synkinetic areas of the face.

Main Outcomes and Measures

Synkinesis assessed using the SAQ (score range, 20-100; lower scores indicate less severe synkinesis) before treatment and 1, 2, and 4 weeks after treatment.

Results

A total of 28 patients (mean [SD] age, 49.1 [18.5] years; 8 [28.6%] male and 20 [71.4%] female), with 6 patients enrolled multiple times, received 38 treatments (15 onabotulinumtoxinA, 13 abobotulinumtoxinA, and 10 incobotulinumtoxinA). No significant difference existed in baseline pretreatment SAQ scores among the 3 groups. Mean (SD) SAQ score improvement at 4 weeks was 41% (31%) for the onabotulinumtoxinA, 42% (20%) for the abobotulinumtoxinA, and 17% (18%) for the incobotulinumtoxinA groups. No significant differences were noted in SAQ score improvements among the 3 groups at weeks 1 and 2 after treatment (week 1 mean improvements of 42% in the onabotulinumtoxinA, 45% in the abobotulinumtoxinA, and 26% in the incobotulinumtoxinA groups; P = .19; week 2 mean improvements of 43% in the onabotulinumtoxinA, 46% in the abobotulinumtoxinA, and 28% in the incobotulinumtoxinA groups; P = .20). The difference in mean SAQ score improvement for abobotulinumtoxinA vs incobotulinumtoxinA from pretreatment to 4 weeks after treatment was not significant (30 vs 12 points; P = .11) despite a significant difference in mean total SAQ score for abobotulinumtoxinA vs incobotulinumtoxinA (40.34 vs 58.00; P = .02).

Conclusions and Relevance

AbobotulinumtoxinA had similar efficacy to onabotulinumtoxinA and incobotulinumtoxinA for the management of facial synkinesis up to 4 weeks after treatment. IncobotulinumtoxinA had significantly less effect on SAQ score improvement than onabotulinumtoxinA at 4 weeks, perhaps because of the shorter duration of action. Shorter intervals between treatments or larger doses may be required when using incobotulinumtoxinA treatment for facial synkinesis.

Trial Registration

clinicaltrials.gov Identifier: NCT03048383.

Level of Evidence

1.

The effects of nasal closure on quality of life in patients with hereditary hemorrhagic telangiectasia

Introduction

Epistaxis is the most common symptom of hereditary hemorrhagic telangiectasia (HHT). Complete nasal closure is one of the treatment options for patients with severe, intractable epistaxis. In our experience, this surgery can be life changing in a positive sense; but many patients as well as their physicians understandably fear that such a procedure will diminish certain aspects of quality of life (QOL).

Methods

Case-control study of HHT patients treated at the University of Utah HHT Center of Excellence with and without nasal closure from January 2005 to January 2016. Patients were matched according to epistaxis severity. Each included patient was issued three surveys: Epistaxis Severity Score (ESS), the Pittsburg Sleep Quality Index (PSQI), and the Nasal Obstruction Symptom Evaluation (NOSE).

Results

After treatment, the mean PSQI and NOSE scores were not significantly different between the two groups. However, the mean ESS score in the nasal closure group was significantly lower at 1.10 compared to the severe epistaxis group with a mean score of 3.99 (P = .027).

Conclusion

The results of this study demonstrate that nasal closure significantly improves epistaxis severity without having a significant effect on sleep or nasal obstruction as they relate to QOL. These findings suggest that nasal closure should be considered for HHT patients with chronic severe epistaxis.

Level of Evidence

4.

An evaluation of the severity and progression of epistaxis in hereditary hemorrhagic telangiectasia 1 versus hereditary hemorrhagic telangiectasia 2

OBJECTIVES/HYPOTHESIS

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular dysplasia whose hallmark symptom is spontaneous recurrent epistaxis. Two major genetic subtypes of this syndrome are HHT1 and HHT2. Severity of epistaxis ranges from occasional low-volume bleeding to frequent large-volume hemorrhage. This study evaluated the severity and progression of epistaxis in HHT1 versus HHT2.

STUDY DESIGN

Retrospective cohort study.

METHODS

A retrospective chart review was performed for 183 genotyped HHT patients seen at our center from 2010 to 2013. Data collected included epistaxis severity score (ESS), age of epistaxis onset, number and type of treatments, age at which treatments were sought, complete blood count values, ferritin, number of telangiectases, blood transfusions, iron therapy history, and patient demographics.

RESULTS

115 subjects with HHT2 were compared to 68 with HHT1. Subjects with HHT2 had a higher ESS compared to HHT1 (P = .043) and a later age of onset of epistaxis (P = .005). HHT2 subjects were more likely to use oral iron (P = .032) and were more likely to seek interventions to control their epistaxis (P = .029).

CONCLUSIONS

HHT2 is associated with more severe epistaxis and a subsequent higher rate of interventions, requiring more aggressive therapy as compared to HHT1.

LEVEL OF EVIDENCE

4.

Treatment of severe refractory epistaxis in hereditary hemorrhagic telangiectasia using a two-flap nasal closure method

BACKGROUND

Nasal closure has been shown to effectively manage severe epistaxis refractory to other treatments in patients with hereditary hemorrhagic telangiectasia (HHT). The nasal closure procedure may be underutilized because of its surgical complexity and flap breakdown.

METHODS

This work is a retrospective review of 13 HHT patients treated for severe epistaxis with nasal closure between 2005 and 2013. Operating room (OR) time, need for revision surgery, preprocedure, and postprocedure epistaxis severity score (ESS), complete blood count values, and Glasgow Benefit Inventory (GBI) questionnaire results were collected for each patient. The technique is described. We characterize a typical nasal closure patient and compare outcomes based on our experience with the traditional 3-flap closure and a simplified 2-flap nasal closure procedure.

RESULTS

The average candidate for nasal closure in this series had an ESS of 7.88, hemoglobin (Hgb) of 8.3 g/dL, and received multiple transfusions, iron therapy, and cautery/coagulation procedures. Average ESS subsequent to nasal closure using the 2-flap method is 0.92 and mean GBI score is 56.3. Comparison of 5 patients who underwent the traditional 3-flap nasal closure procedure and 8 patients receiving the 2-flap nasal closure showed no significant difference in postoperative ESS or GBI metrics. Mean operating room times of the traditional and simplified methods were 3.12 hours and 1.44 hours (p = 0.0001). Mean time to first revision for 8 nasal closure patients was 21.5 months.

CONCLUSION

In short-term follow-up, the 2-flap procedure showed comparable effectiveness with significantly reduced complexity and operative time compared to the traditional nasal closure method.

Salivary gland disorders

Salivary gland disorders include inflammatory, bacterial, viral, and neoplastic etiologies. The presentation can be acute, recurrent, or chronic. Acute suppurative sialadenitis presents as rapid-onset pain and swelling and is treated with antibiotics, salivary massage, hydration, and sialagogues such as lemon drops or vitamin C lozenges. Viral etiologies include mumps and human immunodeficiency virus, and treatment is directed at the underlying disease. Recurrent or chronic sialadenitis is more likely to be inflammatory than infectious; examples include recurrent parotitis of childhood and sialolithiasis. Inflammation is commonly caused by an obstruction such as a stone or duct stricture. Management is directed at relieving the obstruction. Benign and malignant tumors can occur in the salivary glands and usually present as a painless solitary neck mass. Diagnosis is made by imaging (e.g., ultrasonography, computed tomography, magnetic resonance imaging) and biopsy (initially with fine-needle aspiration). Overall, most salivary gland tumors are benign and can be treated with surgical excision.

Decision making in nasal reconstruction

Nasal reconstruction is a challenging and rewarding discipline. The nasal subunit principle dramatically improved the surgeon's ability to reconstruct nasal defects by helping disguise incisions within subunit borders and by providing a tool to help in reconstructive decision making. Selection of the proper reconstruction must include the patient's medicosocial situation and the patient's cosmetic concerns. In addition, functional considerations, such as nasal obstruction, that may result from the chosen reconstruction must be carefully considered. For any defect, the most appropriate reconstructive technique is the simplest and most cost-effective method that meets each individual patient's medical, functional, social, and cosmetic goals.

Weekly chemotherapy with radiation versus high-dose cisplatin with radiation as organ preservation for patients with HPV-positive and HPV-negative locally advanced squamous cell carcinoma of the oropharynx

BACKGROUND

Optimal treatment for locally advanced squamous cell carcinoma of the oropharynx (SCCOP) is not well defined. Here we retrospectively compare survival and toxicities from 2 different organ preservation protocols.

METHODS

The matched dataset consisted of 35 patients from each trial matched for age, stage, smoking, and tumor human papillomavirus (HPV) status. Patients in the University of Michigan Cancer Center (UMCC) trial 9921 were treated with induction chemotherapy (IC) followed by high-dose cisplatin and radiation in responders or surgery in nonresponders. Patients in the UMCC trial 0221 were treated with weekly carboplatin and paclitaxel and radiation.

RESULTS

Survival was comparable for both studies and did not differ significantly across each trial after stratifying by HPV status. Grade 3 and 4 toxicities were more frequent in UMCC 9921. At 6 months posttreatment, gastrostomy tube (G-tube) dependence was not statistically different.

CONCLUSION

These data suggest that survival outcomes in patients with locally advanced SCCOP are not compromised with weekly chemotherapy and radiation therapy, and such treatment is generally more tolerable.

Assessment of Otolaryngic Knowledge in Primary Care Residents

Objectives

(1) Determine the amount of exposure to otolaryngology in medical training of non-otolaryngology residents. (2) Evaluate the general otolaryngic knowledge in these residents.

Study Design

Cross-sectional survey.

Setting

Academic medical center.

Subjects and Methods

A 10-question multiple-choice quiz was given to residents in family practice, pediatrics, emergency medicine, and internal medicine during scheduled educational conferences. Residents were also asked if they ever participated in an otolaryngology rotation during medical school or residency. Medical students and otolaryngology residents completed the quiz to act as controls.

Results

A total of 98 examinations were analyzed (49 non-otolaryngology residents, 10 otolaryngology residents, and 39 second-year medical students). Only 24% of the non- otolaryngology residents had an otolaryngology rotation during medical school. The same amount (24%) had a rotation during residency. The average percentage correct on the quiz was 48%, 56%, and 92% for medical students, non-otolaryngology, and otolaryngology residents, respectively ( P < 0.05). Questions with surprising results included one with an endoscopic image of the middle turbinate and examinees asked to identify the structure (non-otolaryngology residents = 18% correct). A laryngectomy stoma was shown and participants asked what would happen if the stoma was occluded for 10 minutes (non-otolaryngology residents = 20% correct).

Conclusion

In this sample of non-otolaryngology residents, a minority experienced a clinical rotation in otolaryngology during medical school or residency. This nonvalidated questionnaire also suggested significant deficiencies in basic otolaryngic knowledge in these residents. Identifying mechanisms to improve exposure to otolaryngology in the medical training curriculum is needed.

The Young's Procedure for Severe Epistaxis from Hereditary Hemorrhagic Telangiectasia

Background

Surgical treatment of epistaxis in hereditary hemorrhagic telangiectasia (HHT) has historically been managed with the laser procedure or the septodermoplasty procedure. For transfusion-dependent patients with severe epistaxis we have been performing the Young's procedure or surgical closure of the nostrils. The objective of this study was to report treatment of severe epistaxis related to HHT with the Young's procedure and assess patient outcome.

Methods

Patients with severe iron or blood transfusion–dependent epistaxis who underwent a Young's procedure in three otolaryngology HHT centers were reviewed. Patients were evaluated for postoperative epistaxis and subjective outcome.

Results

Forty-three patients underwent a Young's procedure for severe epistaxis and were observed for a mean of 34 months. The procedure was well tolerated by all patients and 30 of 36 patients (83%) experienced complete cessation of bleeding after the Young's procedure. Patients had a mean increase in hemoglobin of 4.68 g/dL after the procedure. The average Glasgow Benefit Inventory score after surgery was 43.56. No patients requested a reversal of the procedure.

Conclusion

The Young's procedure is a safe and efficacious procedure with complete cessation of epistaxis in most patients with severe epistaxis and HHT.

Diagnostic modalities for distant metastasis in head and neck squamous cell carcinoma: are we changing life expectancy?

OBJECTIVES/HYPOTHESIS

To determine if the various imaging modalities for distant metastasis (DM) diagnosis alters life expectancy in head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

Retrospective.

METHODS

One hundred seventy patients (mean age, 59.1 years; male:female, 135:35) with HNSCC who developed DM were reviewed. The main outcome measures were the method of DM diagnosis and time from DM diagnosis to death while controlling for clinical parameters (age, gender, tobacco status, primary tumor site, initial TNM classification, number and site of DM, administration of palliative chemotherapy).

RESULTS

Tumor subsites were: 40 oral cavity, 75 oropharynx, 36 larynx, 10 hypopharynx, one nasopharynx, and eight unknown primary. Of the patients, 16.5% (28/170) had distant metastasis at presentation; the remaining 142 patients were diagnosed with DM at a median of 324 days from diagnosis. Although patients diagnosed with DM by positron-emission tomography (PET) scan were more likely to have multiple DM sites (P = .0001), there were no differences in life expectancy in patients who were diagnosed with or without PET scan (median, 185 vs. 165 days, P = .833). There were no differences in life expectancy based on age, gender, site of primary tumor, or number/site of DM. The use of palliative chemotherapy resulted in a significantly longer life expectancy (median, 285 vs. 70 days; P = .001).

CONCLUSIONS

Although a PET scan is more likely to diagnose multiple DM sites, there was no difference in life expectancy based on imaging modality. Patients who are symptomatic from their distant metastasis have a worse life expectancy, and palliative chemotherapy was able to increase life expectancy, even in patients who were symptomatic from the distant metastasis.

Orbitocranial approach for treatment of adenoid cystic carcinoma of the lacrimal gland

OBJECTIVES

Multiple treatment options exist for management of adenoid cystic carcinoma of the lacrimal gland. Our objective was to perform an analysis of outcomes in a cohort of patients with adenoid cystic carcinoma of the lacrimal gland treated identically with an orbitocranial approach.

METHODS

We performed a retrospective review of 7 consecutive patients who presented to a tertiary care academic medical center between 1995 and 2009 with adenoid cystic carcinoma of the lacrimal gland.

RESULTS

All patients were treated with an orbitocranial approach to tumor resection followed by postoperative radiotherapy. The mean and median follow-up times were 39 and 19 months, respectively (range, 7 to 138 months). Six patients had orbital reconstruction using free tissue transfer, and 1 patient had a split-thickness skin graft to line the orbital cavity. Two patients developed distant metastases 18 months and 29 months after surgery and ultimately died with disease. Five patients are alive without disease.

CONCLUSIONS

The orbitocranial approach followed by postoperative irradiation achieves excellent local and regional control rates for adenoid cystic carcinoma of the lacrimal gland, although patients remain at risk long-term for distant metastases. Orbital bone removal to obtain adequate margins should be a routine part of tumor resection for these malignancies.

Reconstructive perspectives of cutaneous defects involving the nasal tip: a retrospective review

OBJECTIVES

To create an algorithm that derives our preferred reconstruction technique for cutaneous defects involving the nasal tip and to review the management and outcomes of patients with nasal tip cutaneous defects after their initial reconstruction.

METHODS

A retrospective review of patients undergoing repair of cutaneous defects involving the nasal tip between January 2006 and January 2009. After data compilation, a defect-based algorithm deriving our repair technique was created.

RESULTS

Seventy-two patients were identified: 57% underwent full-thickness skin graft repair (n = 41), 19% underwent forehead flap repair (n = 14), and 17% underwent bilobe flap repair (n = 12). The remaining 7% underwent repair using nasal cutaneous flaps harvested adjacent to the defect (n = 5). Nasal tip defect involvement of an adjacent nasal aesthetic unit was the most critical factor in selecting a reconstruction technique. Further categorization by the presence of nasal ala involvement, cartilage exposure, and defect surface area allowed reliable prediction of our reconstruction technique. Dermabrasion was routinely performed early in the postoperative course (25% [18 of 72 patients]). Corticosteroid injection was commonly used for those undergoing forehead flap (71% [10 of 14 patients]) and bilobe flap (50% [6 of 12 patients]) repair. Aesthetic revision surgery was infrequently required (15% [11 of 72 patients]). All aesthetic outcomes were good or satisfactory.

CONCLUSION

The included algorithm offers a systematic approach for managing cutaneous defects involving the nasal tip and derives our preferred technique with high reliability.

Esthesioneuroblastoma: Results and Outcomes of a Single Institution's Experience

OBJECTIVES

Analysis of outcomes of a cohort of patients with esthesioneuroblastoma.

DESIGN

Retrospective cohort analysis.

SETTING

PATIENTS presenting with esthesioneuroblastoma from 1994 to 2006 in a tertiary care academic medical center.

PATIENTS

Fifteen consecutive patients diagnosed as having esthesioneuroblastoma were treated during this time period using a subcranial resection. The mean follow-up is 75 months (range, 2 to 240 mos).

RESULTS

The overall survival was 100% and the overall disease-free survival was 49% and 24% at 5 and 15 years, respectively. PATIENTS treated with radiation therapy following surgical resection had a 5- and 15-year disease-free survival of 83.3% compared with a 5- and 15-year disease-free survival of 26.7% and 0%, respectively, for patients whose initial treatment was surgery alone. The mean time to recurrence was 82.1 months. None of the patients had a decrease in Karnofsky Performance Score following subcranial resection.

CONCLUSIONS

PATIENTS with esthesioneuroblastoma whose initial treatment consists of surgical resection followed by radiation therapy have a longer disease-free survival than patients treated with surgery alone. However, initial treatment modality did not have an effect on survival. Long-term, close follow-up is necessary to identify recurrences, which can be treated with a high degree of success.

Perioperative outcomes in patients undergoing the transglabellar/subcranial approach to the anterior skull base

We analyzed the effect of predefined patient demographic, disease, and perioperative variables on the rate of complications in the perioperative period following subcranial surgery for anterior skull base lesion. A secondary goal of this study was to provide a benchmark rate of perioperative mortality and morbidity through comprehensive analysis of complications. Retrospective review of a consecutive series of patients (n = 164) who underwent the transglabellar/subcranial approach to lesions of the anterior skull base between December 1995 and November 2009 in a tertiary referral center. Main outcome measures were perioperative morbidity and mortality. No perioperative mortalities were observed over the period of consecutive review. The overall complication rate was 28.7%, with 30 (18%) patients experiencing major complication. Multivariate analysis revealed that the following variables were independent predictors of perioperative complication of any type: positive margins on final pathology, perioperative lumbar drain placement, and dural invasion. The subcranial approach provides excellent access to the anterior skull base with zero mortality and acceptable morbidity in comparison with other contemporary open surgical approaches. It should be considered a procedure with distinct advantages in terms of perioperative morbidity and mortality when selecting a therapeutic approach for patients with anterior skull base lesions.

Long-term results of carbon dioxide laser resurfacing of the face

OBJECTIVE

To evaluate the long-term effectiveness of, and the complications associated with, carbon dioxide laser treatment of rhytidosis and solar aging.

METHODS

This retrospective report describes our experience with 47 patients who underwent entire facial carbon dioxide laser resurfacing.

RESULTS

The mean improvement in facial rhytid score at long-term follow-up was 45%. This improvement was consistent in all facial subsites. With the exception of 1 case of hyperpigmentation, which resolved within 2 years of treatment, hypopigmentation was the only long-term adverse effect. This complication was present in 6 patients (13%). The patients who developed hypopigmentation were more likely to have a greater response to treatment.

CONCLUSION

Our findings show that carbon dioxide laser resurfacing is a safe and effective treatment for facial rhytids.

Cardiovascular monkey telemetry: Sensitivity to detect QT interval prolongation

INTRODUCTION

Preclinical evaluation of delayed ventricular repolarization manifests electrocardiographically as QT interval prolongation and is routinely used as an indicator of potential risk for pro-arrhythmia (potential to cause Torsades de Pointes) of novel human pharmaceuticals. In accordance with ICH S7A and S7B guidelines we evaluated the sensitivity and validity of the monkey telemetry model as a preclinical predictor of QT interval prolongation in humans.

METHODS

Cardiovascular monitoring was conducted for 2 h pre-dose and 24 h post-dosing with Moxifloxacin (MOX), with a toxicokinetic (TK) evaluation in a separate group of monkeys. In both studies, MOX was administered orally by gavage in 0.5% methylcellulose at 0, 10, 30, 100, 175 mg/kg. Each monkey received all 5 doses using a dose-escalation paradigm. Inherent variability of the model was assessed with administration of vehicle alone for 4 days in all 4 monkeys (0.5% methylcellulose in deionized water).

RESULTS

MOX had no significant effect on mean arterial pressure, heart rate, PR or QRS intervals. MOX produced significant dose-related increases in QTc at doses of 30 (Cmax=5.5+/-0.6 microM), 100 (Cmax=16.5+/-1.6 microM), and 175 (Cmax=17.3+/-0.7 microM) mg/kg with peak increases of 22 (8%), 27 (10%), and 47 (18%) ms, respectively (p<or=0.05; compared to vehicle).

DISCUSSION

In conclusion, we have developed a reproducible, sensitive and reliable primate telemetry model in rhesus monkeys, which exhibits low inherent intra-animal variability and high sensitivity to detect small but significant increases in QT/QTc interval (approximately 4%) with MOX in the same range of therapeutic plasma concentrations attained in humans. Therefore, the primate telemetry model should be considered an important preclinical predictor of QT prolongation of novel human pharmaceuticals.

Chondroitin Sulfate Hydrogel and Wound Healing in Rabbit Maxillary Sinus Mucosa

OBJECTIVES/HYPOTHESIS

Chondroitin sulfate (CS) is a glycosaminoglycan in the extracellular matrix of all vertebrates. A biocompatible, nonimmunogenic, pliable hydrogel preparation of CS has recently been produced and has shown benefit in wound healing in murine and porcine epidermis. The objective of the current experiment is to compare the wound healing properties of CS hydrogel versus no treatment in wounds of the maxillary sinus mucosa.

STUDY DESIGN

Prospective investigation in an animal model.

METHODS

A 6 mm wound was created in bilateral maxillary sinuses of 17 New Zealand white rabbits. CS hydrogel (case) and no dressing (control) were randomly assigned to one side each as wound treatment. Wounds were examined ex vivo at 2, 4, 6, 10, and 14 day postinjury intervals. Wound diameter was measured microscopically by a blinded investigator. Representative specimens were examined histologically.

RESULTS

The CS disc was partially integrated into the wounds at the 4-day interval and completely integrated by the 6-day interval. The average wound diameters for the case versus control side were similar at 2 days (3.75 mm vs. 4.42 mm) but differed significantly at 4 days (2.86 mm. vs. 3.80 mm., P =.035). At 6 days, the wounds could not be discerned on either the case or control sides. However, histologic analysis revealed accelerated healing with the CS treatment. The treated wounds displayed respiratory epithelium as opposed to the squamous epithelium exhibited on the untreated sides.

CONCLUSIONS

Despite some limitations, the New Zealand white rabbit is an effective model for the study of sinonasal wound healing. CS hydrogel accelerates wound healing in sinonasal mucosa at a 4-day endpoint. We propose that the CS hydrogel acts as a surrogate extracellular matrix, serving as a repository for cytokines and growth factors produced by the regenerating mucosa. It may also provide a structural framework for fibroblasts and epithelial regeneration. Further study is necessary to establish this relationship.

Hyaluronic acid: its role in voice

The extracellular matrix (ECM), once regarded simply as a structural scaffold, is now recognized as an important modulator of cellular behavior and function. One component that plays a prominent role in this process is hyaluronic acid (HA)--a molecule found in many different tissues. Research into the roles of HA indicates that it plays a key role in tissue viscosity, shock absorption, and space filling. Specifically, research into the role of HA in laryngology indicates that it has profound effects on the structure and viscosity of vocal folds. This article provides an introduction to the structure and biological functions of HA and its importance in voice. In addition, an overview of the pharmaceutical applications of HA is discussed.

Sudden Productivity Collapse Associated with the Triassic-Jurassic Boundary Mass Extinction

The end-Triassic mass extinction is one of the five most catastrophic in Phanerozoic Earth history. Here we report carbon isotope evidence of a pronounced productivity collapse at the boundary, coincident with a sudden extinction among marine plankton, from stratigraphic sections on the Queen Charlotte Islands, British Columbia, Canada. This signal is similar to (though smaller than) the carbon isotope excursions associated with the Permian-Triassic and Cretaceous-Tertiary events.

Enhancing paracellular permeability by modulating epithelial tight junctions

The intestinal epithelium is a major barrier to the absorption of hydrophilic drugs. The presence of intercellular junctional complexes, particularly the tight junctions (zona occludens), renders the epithelium impervious to hydrophilic drugs, which cannot diffuse across the cells through the lipid bilayer of the cell membranes. There have been significant advances in understanding the structure and cellular regulation of tight junctions over the past decade. This article reviews current knowledge regarding the physiological regulation of tight junctions and paracellular permeability, and recent progress towards the rational design of agents that can effectively and safely increase paracellular permeability via modulation of tight junctions.

Altered river morphology in south africa related to the permian-triassic extinction

The Permian-Triassic transition in the Karoo Basin of South Africa was characterized by a rapid and apparently basin-wide change from meandering to braided river systems, as evidenced by preserved sedimentary facies. This radical changeover in river morphology is consistent with geomorphic consequences stemming from a rapid and major die-off of rooted plant life in the basin. Evidence from correlative nonmarine strata elsewhere in the world containing fluvial Permian-Triassic boundary sections suggests that a catastrophic terrestrial die-off of vegetation was a global event, producing a marked increase in sediment yield as well as contributing to the global delta(13)C excursion across the Permian-Triassic boundary.

Sudden and Gradual Molluscan Extinctions in the Latest Cretaceous of Western European Tethys

Incompleteness of the fossil record has confounded attempts to establish the role of the end-Cretaceous bolide impact in the Late Cretaceous mass extinctions. Statistical analysis of latest Cretaceous outer-shelf macrofossils from western European Tethys reveals (i) a major extinction at or near the Cretaceous-Tertiary (K-T) boundary, probably caused by the impact, (ii) either a faunal abundance change or an extinction of up to nine ammonite species associated with a regression event shortly before the boundary, (iii) gradual extinction of most inoceramid bivalves well before the K-T boundary, and (iv) background extinction of approximately six ammonites throughout the latest Cretaceous.

Oxygen free radical activity during live E. coli septic shock in the dog

Free radicals generated during purine catabolism or by activated granulocytes cause tissue injury by peroxidation of lipid membranes. In a canine model of sepsis initiated by intravenous live Escherichia coli, fluorescent products of lipid peroxidation (FP) were measured in serum. Four groups of five dogs infused with 10(9)E. coli/kg were analyzed--I: no further treatment; II: prior depletion of granulocytes with a cytotoxic antibody; III: pre-treatment with superoxide dismutase and catalase; and IV: resuscitation after bacterial infusion to maintain cardiac output greater than 80% of pre-bacteremic levels. In Groups I, II, and III, cardiac output fell to less than 50% of baseline within 1 hr and remained there throughout the study. FP in Groups I and II rose to greater than 200% of baseline (P less than .02 and less than .03). In Groups III and IV, FP did not rise significantly from baseline. The rise in serum FP and the prevention of this rise by-treatment with antioxidants indicate generation of oxygen radicals. Their presence had no effect on hemodynamic parameters. Granulocyte depletion did not alter appearance of FP; however, prevention of low cardiac output blocked FP formation. These data suggest that oxygen free radicals were generated by tissue ischemia, rather than by granulocytes, in this model of septic shock.

Vaccination of fish: a practical view

Commercial vaccines giving protection against three important bacterial fish diseases (enteric redmouth, furunculosis and vibriosis) became available in the United Kingdom in 1983. The degree of protection obtained and the cost effectiveness vary according to the method of presentation (injection, dipping or spraying and oral dosing). These methods and the optimum time for vaccination are described.

Prolonged heparin therapy in pregnancy causes bone demineralization

The relation of heparin therapy to osteoporosis was assessed in a retrospective analysis of 20 women treated during and after pregnancy with subcutaneous heparin for thromboembolism prophylaxis. The phalangeal cortical area ratio was significantly less after long term therapy (greater than 25 weeks) compared with that after short term therapy (less than 7 weeks). The same trend was found in the metacarpal area ratio, although this did not reach statistical significance. The changes were most marked in a woman who had received heparin also in a previous pregnancy. No correlations were found between duration of therapy and back pain, conventional radiology of lumbar spine or the Singh index of femoral trabecular pattern which were within the normal range in all patients. The findings indicate a dose-related demineralization process associated with prophylactic heparin therapy in pregnancy. The correct methods of and criteria for thromboembolism prophylaxis in pregnancy need critical re-examination.

Finger sepsis

Images

Identification of staphylococcal Panton-Valentine leukocidin as a potent dermonecrotic toxin

The Panton-Valentine leukocidin of Staphylococcus aureus was shown to exhibit a potent dermonecrotic effect when injected intradermally into rabbits. This effect could be abrogated by immunizing animals with the F component or both components, but immunization with the S component appeared to exacerbate certain of the intradermal responses.

Effect immunization with highly purified alpha- and beta-toxins on staphylococcal mastitis in rabbits

Experiments were carried out to determine whether immunization of female rabbits with highly purified staphylococcal alpha- or beta-toxins would protect them against intramammary challenge with staphylococci. High circulating anti-alpha-toxin titers reduced the lethal hemorrhagic edematous form of the disease ("blue-breast") produced by strains BB and Compton 201 to a localized chronic abscess form. No such protection was afforded by high anti-beta-toxin titers. Immunization with alpha- or beta-toxins produced no change in the clinical picture of the disease produced by CN.6708, a strain of Staphylococcus responsible for a natural outbreak of abscess-type rabbit mastitis. From these experiments it would appear that alpha-toxin is a key antigen in the blue-breast form of rabbit mastitis. Since the abscess form of the disease was not prevented by immunization with either alpha- or beta-toxin, other virulence factors must be acting to produce this more localized disease.

Antibody titres of antilymphocytic sera and globulins determined by immunofluorescence and their correlation with immunosuppressive activity

Human and mouse lymphocytes have been treated with the appropriate antilymphocytic serum or globulin and the indirect fluorescent technique applied. A method of scoring the observed fluorescence has been devised. A good general degree of correlation has been demonstrated between the antibody titres of the antilymphocytic sera and globulins, determined by immunofluorescence and the immunosuppressive activity as measured by graft prolongation. The test is reliable, rapid and reproducible, but absolute reliance on the test is not advocated as a precise measure of immunosuppressive activity. The immunofluorescent technique is invaluable in the analysis of serum samples from horses undergoing active immunization.