The temporalis muscle flap for reconstruction after head and neck oncologic surgery

OBJECTIVE

To explain the applications, technique, and potential complications of the temporalis muscle flap used for immediate or delayed reconstruction of head and neck oncologic defects.

STUDY DESIGN

Fresh cadaver dissection and 5-year retrospective chart review.

METHODS

A fresh cadaver dissection was performed to illustrate the surgical anatomy of the temporalis muscle flap with attention to specific techniques useful in avoiding donor site morbidity (facial nerve injury and temporal hollowing). A chart review was performed for 13 consecutive patients from the last 5 years who underwent temporalis muscle flap reconstruction after oncologic resection of the lateral and posterior pharyngeal wall, hard and soft palate, buccal space, retromolar trigone, and skull base.

RESULTS

Patient follow-up ranged from 2 to 45 months. Nine patients had radiation therapy. There were no cases of flap loss. Resection of the zygomatic arch followed by wire fixation facilitates flap rotation and minimizes trauma to the flap during placement into the oropharynx. Preservation of the temporal fat pad attachment to the scalp flap decreases temporal hollowing and protects the facial nerve. Replacing the zygoma and preserving the anterior third of the temporalis muscle in situ further diminishes donor-site hollowing.

CONCLUSIONS

Compared with other regional flaps, such as the pectoralis myocutaneous flap, the temporalis muscle flap is associated with low donor-site esthetic and functional morbidity and offers great flexibility in reconstruction. The temporalis muscle flap is a useful, reliable flap that belongs in the armamentarium of surgeons who are involved with reconstruction of head and neck tissue defects.

Acoustic role of the buttress and posterior incudal ligament in human temporal bones

OBJECTIVES

In middle ear surgery using intact ear canal wall techniques, the buttress, which is the bony bridge at the medial end of the posterior-superior bony ear canal, is commonly retained during posterior tympanotomy. In some cases, the surgical exposure may be improved by resectioning the buttress, and this requires sectioning the posterior incudal ligament. To date, the acoustic effects of removing the buttress with sectioning of the attached ligament have not been studied.

METHOD

Using a laser Doppler vibrometer system, 15 human cadaver temporal bones were measured with 80 dB sound pressure level at the tympanic membrane over the 0.1 to 10 kHz frequency range.

RESULT

The resection of the buttress and sectioning the posterior incudal ligament had no effect on stapes footplate velocity.

CONCLUSION

These results suggest that the posterior incudal ligament does not play a significant role in the acoustic function of the ossicles.

Human middle-ear sound transfer function and cochlear input impedance

The middle-ear pressure gain, defined as the ear canal sound pressure to cochlear vestibule pressure gain, GME, and the ear canal sound pressure to stapes footplate velocity transfer function, SVTF, simultaneously measured in 12 fresh human temporal bones for the 0.05 to 10 kHz frequency range are reported. The mean GME magnitude reached 23.5 dB at 1.2 kHz with a slope of approximately 6 dB/octave from 0.1 to 1.2 kHz and -6 dB/octave above 1.2 kHz. From 0.1 to 0.5 kHz, the mean GME phase angle was 51 degrees, rolling off at -78 degrees /octave above this frequency. The mean SVTF magnitude reached a maximum of 0.33 mm s(-1)/Pa at 1.0 kHz with nearly the same shape in magnitude and phase angle as the mean GME. The ratio of GME and SVTF provide the first direct measurements of Z(c) in human ears. The mean Z(c) was virtually flat with a value of 21.1 acoustic GOmega MKS between 0.1 and 5.0 kHz. Above 5 kHz, the mean Z(c) increased to a maximum value of 49.9 GOmega at 6.7 kHz. The mean Z(c) angle was near 0 degrees from 0.5 to 5.0 kHz, decreasing below 0.5 kHz and above 5 kHz with peaks and valleys.

Current status of topical nasal antimicrobial agents

The nasal cavity and paranasal sinuses are probably one of the last frontiers in the head and neck region where the use of topical antimicrobial agents is not yet established. Although the anatomy of the nasal cavity and the paranasal sinuses can theoretically be exploited for the administration of antimicrobials in rhinosinusitis, very few studies have been conducted to test the feasibility of this mode of therapy. We review the anatomical and physiological factors that should be considered in the use of topical nasal antimicrobial agents and the current status of topical nasal antimicrobial usage, and we make recommendations for the administration of topical nasal antimicrobial agents.

Kinetic analysis of LY320236: competitive inhibitor of type I and non-competitive inhibitor of type II human steroid 5alpha-reductase

Type I and type II steroid 5alpha-reductases (5alpha-R) catalyze the conversion of testosterone (T) to dihydrotestosterone (DHT). LY320236 is a benzoquinolinone (BQ) that inhibits 5alpha-R activity in human scalp skin (Ki(typeI)=28.7+/-1.87 nM) and prostatic homogenates (Ki(typeII)=10.6+/-4.5 nM). Lineweaver-Burk, Dixon, and non-linear analysis methods were used to evaluate the kinetics of 5alpha-R inhibition by LY320236. Non-linear modeling of experimental data evaluated V(max) in the presence or absence of LY320236. Experimental data modeled to the following equation 1v=+ fixing the In0c value equal to 1.0 or 0 are consistent with non-competitive or competitive inhibition, respectively. LY320236 is a competitive inhibitor of type I 5alpha-R (In0c=0, Ki=3.39+/-0.38, RMSE = 1.300) and a non-competitive inhibitor of type II 5alpha-R (In0c=1, Ki=29. 7+/-3.4, RMSE = 0.0592). These data are in agreement with linear transformation of the data using Lineweaver-Burk and Dixon analyses. These enzyme kinetic data support the contention that the BQ LY320236 is a potent dual inhibitor with differing modes of activity against the two known human 5alpha-reductase isozymes. LY320236 represents a class of non-steroidal 5alpha-R inhibitors with potential therapeutic utility in treating a variety of androgen dependent disorders.

Advantages of a new miniature hearing aid for mild to moderate hearing loss

OBJECTIVES/HYPOTHESIS

To evaluate the performance of a new, miniature, behind-the-ear hearing aid designed for individuals with mild to moderate high-frequency hearing loss who need an aid but are reluctant to try one. The aid is essentially invisible, leaves the ear canal open, and can be fit in less than 30 minutes without an ear impression. The cost is less than $500.

STUDY DESIGN

A 4-week trial of the aid in 63 ears (62 subjects) with mild to moderate bilateral hearing loss.

METHODS

A questionnaire was completed at the end of the study by each subject asking them to evaluate several features of the aid (cosmesis, comfort, understanding speech, amplification, and so forth) and to compare their unaided performance in quiet and in noise with the test hearing aid. A rating scale of 1 to 10 was used, with 10 being excellent and 1 poor.

RESULTS

Subjective improvement in understanding speech in both quiet (5.8-->7.3) and noise (4.6-->5.9) occurred with the aid. Cosmesis, comfort, and appearance were highly rated (mean scores, > 8).

CONCLUSIONS

This aid appears to have several features (comfort, cost, performance, and cosmesis) that make it ideal as a first aid for patients with mild to moderate losses.

Prevention and correction of temporal hair loss in rhytidectomy

Routine incisions in the temporal area for rhytidectomy often remove hair-bearing skin anterior to the ear. This results in a cosmetic deformity, making the surgical intervention clearly visible. This is especially problematic for revision rhytidectomy or for patients with naturally high hairlines. This article describes a systematic approach to the temporal hairline and introduces a novel, hair-bearing, transposition flap that corrects iatrogenic loss of the preauricular tuft of hair.

Growth regulation of prostatic stromal cells by prostate-specific antigen

BACKGROUND

Prostate-specific antigen (PSA) is a serine protease that can cleave insulin-like growth factor-binding protein-3 (IGFBP3), thereby decreasing its affinity for insulin-like growth factor-I (IGF-I). Dissociation of the IGF-I-IGFBP3 complex renders IGF-I available to bind to its receptor and stimulates cellular proliferation. We evaluated the potential for PSA to modulate the effects of IGF-I and IGFBP3 on the proliferation of human benign prostatic hyperplasia (BPH)-derived fibromuscular stromal cells in primary cultures.

METHODS

We cultured BPH-derived stromal cells for 48 hours in serum-free RPMI-1640 medium supplemented with 0.2% bovine serum albumin and studied the effects of IGF-I, IGFBP3, PSA, and ZnCl(2) at varying concentrations. Differences in cell growth between control and treated cultures were evaluated by use of Dunnett's test. Concentration-related trends were evaluated by linear regression of log-transformed concentrations of test reagents on BPH-derived stromal cell number responses. Statistical tests were two-sided.

RESULTS

We observed a concentration-dependent proliferative response of BPH-derived stromal cells to IGF-I. IGFBP3 inhibited this response in a concentration-dependent fashion. IGFBP3 alone had no effect on stromal cell proliferation. When stromal cells were incubated with PSA alone or with PSA, IGF-I, and IGFBP3, an increase in stromal cell numbers that was dependent on PSA concentration was evident in both instances. Zinc, an endogenous inhibitor of PSA enzymatic activity, was able to attenuate the stimulatory effect of PSA at intraprostatic physiologic concentrations.

CONCLUSIONS

These results are consistent with the idea that PSA can modulate in vitro interactions between IGF-I and IGFBP3 and suggest that PSA may play a role in the regulation of human prostatic fibromuscular cell growth.

Efficacy of octyl-2-cyanoacrylate tissue glue in blepharoplasty. A prospective controlled study of wound-healing characteristics

OBJECTIVE

To compare the surgical efficacy and wound-healing characteristics of the tissue adhesive octyl-2-cyanoacrylate (approved by the Food and Drug Administration) with traditional suture closure in upper blepharoplasty.

METHODS

Prospective, randomized, blinded study comparing cosmetic and functional outcome and time efficiency. Twenty subjects underwent upper eyelid blepharoplasty. Each patient had a control side and an experimental side determined randomly. One eyelid incision was closed with octyl-2-cyanoacrylate (Dermabond; Ethicon Inc, Somerville, NJ) tissue glue, and the other with 6.0 suture (polypropylene or fast-absorbing gut). Comparisons were performed for the time for closure by each method, wound healing, and patient satisfaction. Macrophotographs of the wounds at 1, 2, and 4 weeks after surgery were graded by 5 observers blinded to the closure method, using a 10-point scale and a modified Hollander wound evaluation scale.

RESULTS

No statistically significant difference was found between the quality of octyl-2-cyanoacrylate closure and suture closure at 1 month. There were no differences in wound complications, duration of healing, inflammation, or final incision appearance. By 2 weeks, the sides were indistinguishable in 15 (75%) of the patients. Time for closure averaged 7 minutes with suture and 8 minutes with glue.

CONCLUSIONS

Octyl-2-cyanoacrylate glue is an excellent alternative to suture closure, producing equivalent quality of closure at all time points and no difference in appearance. This adhesive was sufficient to withstand the forces of closure in upper eyelid blepharoplasty without dehiscence in the absence of sutures.

Evaluation of a cement incus replacement prosthesis in a temporal bone model

In reconstruction of the ossicular chain for a damaged incus, it is important that the incus replacement prosthesis (IRP) length is ideal in order to provide optimal tension between the tympanic membrane or malleus and stapes head to achieve the best post-operative hearing result. Even though the length of commercially available IRPs can be adjusted, it still may be difficult to achieve clinically. We describe experiments in a human temporal bone model using dental cement as an IRP after removal of the incus. This cement IRP (CIRP) hardens in situ and becomes the length of the gap to be spanned so that tension should be ideal. Two different CIRPs were studied; one was a conventional rod-type CIRP connecting either the umbo or mid-malleus handle to the stapes head. The second was a Y-shaped CIRP (Y-CIRP), connecting two sites on the malleus to the stapes head. The wide Y-CIRP connected the malleus head and umbo to the stapes head, while the narrow Y-CIRP connected the malleus neck and mid-handle to the stapes head. The acoustic performance of these experimental CIRPs was studied using a laser Doppler vibrometer system in 12 fresh human temporal bones. The CIRP demonstrated better acoustic performance than conventional IRPs studied previously in the same model. While all the CIRPs showed similar function below 2.0 kHz, the narrow Y-CIRP appeared best above 3.0 kHz. A prosthesis of this type may have an acoustic advantage over conventional IRPs.

Who needs a sleep test? The value of the history in the diagnosis of obstructive sleep apnea

Many experts believe that a polysomnogram to screen for obstructive sleep apnea should be performed on every patient who has a history of loud snoring and sleepiness. In contrast, the author believes that with a careful history and physical examination, there is no need to study all such patients, at least not until home polysomnography units become as convenient and economical as pulse oximetry.

Analysis of the best site on the stapes footplate for ossicular chain reconstruction

Experiments were performed in 22 fresh human temporal bones to compare the relative acoustic function of three stapes footplate sites for an incus stapes superstructure replacement prosthesis (I-SRP). The three sites evaluated were the anterior, centre and posterior footplates. A new round window (RW) measurement method was used to make the comparisons. A small glass microsphere was placed in the centre of the RW as a target. A Polytec laser Doppler vibrometer was used to measure round window displacement in response to 50 pure tones between 200 and 10,000 Hz presented at 80 dB SPL at the tympanic membrane (TM). After a baseline measurement of RW displacement in the intact temporal bone, the incus was removed and a cement I-SRP (CIRP) formed between the mid-malleus handle and each of the three test footplate sites, in random order. RW displacement was again measured after placement of the CIRP at each of three sites. We found the centre site to be 3.0-7.0 dB better than the anterior site above 2,000 Hz. There were no differences between the anterior and centre sites below 2,000 Hz. The posterior site was the worst at all frequencies.

Radiofrequency energy tissue ablation for the treatment of nasal obstruction secondary to turbinate hypertrophy

OBJECTIVE/HYPOTHESIS

We hypothesized that the success rate of radiofrequency energy (RFe) tissue ablation of the inferior turbinate for nasal obstruction achieved by previous investigators would be improved by using a longer needle electrode and creating two lesions per turbinate.

METHODS

Ten patients with nasal obstruction secondary to inferior turbinate hypertrophy were prospectively enrolled. A 40-mm needle delivered RFe to two sites in each inferior turbinate. Patients used a visual analog scale (VAS) to grade nasal obstruction preoperatively and at 1 week and 8 weeks after surgery. Preoperative and postoperative digital images of the nasal cavity were graded for obstruction (0% to 100%) in a blinded manner.

RESULTS

All patients (100%) were subjectively improved at 8 weeks. Mean obstruction (VAS) improved from 50%+/-21% to 16%+/-15% (right side) and from 53%+/-29% to 13%+/-13% (left side). Mean improvements were 68% (right side) (P = .004) and 75% (left side) (P = .001). Mean obstruction graded during blinded review of nasal cavity images improved from 73.5%+/-8% to 51%+/-8% (right side) and from 76%+/-6% to 64%+/-7% (left side). Of nine patients using medications for nasal obstruction before treatment, eight (89%) noted no further need for medications at 8 weeks.

CONCLUSION

The use of RFe for submucosal tissue ablation in the hypertrophied inferior turbinate is an effective modality for reducing symptoms of nasal obstruction. Improved results may occur by using a longer needle and creating two lesions per turbinate. Of patients in this study, 100% reported improvement of nasal obstruction.

A human temporal bone study of stapes footplate movement

OBJECTIVE

This study was designed to determine whether stapes movement is pistonlike or complex.

BACKGROUND

The literature provides conflicting information on whether stapes footplate motion is only pistonlike or has other types of movement, such as hingelike or rocking.

METHODS

Using 10 freshly harvested human cadaver temporal bones, 3 targets were placed on the stapes footplate through an extended facial recess approach. The targets were 0.5-mm pieces of reflective adhesive material positioned on the long axis of the footplate at the anterior crus, central footplate, and posterior crus. Displacement and phase of the three targets were measured from 0.2 to 10 kHz at a 90dB sound pressure level input at the tympanic membrane. The measuring system was a sophisticated laser Doppler vibrometer (LDV). A computer program (Tymptest) calculated footplate displacement and relative phase at the three sites and the ratio of anterior-posterior rocking movement of the footplate long axis to displacement at the center.

RESULTS

Below 2.0 kHz, stapes vibration is predominately pistonlike. Above 2.0 kHz, anterior-posterior rocking motion increases logarithmically with frequency, and, near 4.0 kHz, rocking and pistonlike motion are approximately equal.

CONCLUSIONS

Stapes footplate vibration is primarily pistonlike up to 2.0 kHz but becomes more complex at higher frequencies because of an increase in anterior-posterior rocking motion. Hingelike movements were not observed. This information may be helpful in the design of ossicular replacement prostheses that mimic or improve upon normal stapes vibration.

Radiofrequency ablation of the nerve to the corrugator muscle for elimination of glabellar furrowing

Glabellar furrows are caused by hyperdynamic activity of the corrugator supercilii muscles. A minimally invasive, percutaneous technique for eliminating glabellar furrows is described. An insulated, bipolar needle is inserted vertically through the eyebrow skin to entrap the corrugator nerve plexus. To confirm proper positioning, a stimulating current is delivered to the needle during observation of corrugator supercilii muscle response. Radiofrequency energy is then delivered to the needle, thereby ablating the intervening nerve tissue. This technique is in the early stage of optimization and is being evaluated in an ongoing Stanford University Human Subjects protocol, Stanford, Calif. The preliminary results are reported herein.

Direct bonded orthodontic brackets for maxillomandibular fixation

OBJECTIVES/HYPOTHESIS

Mandibular fracture treatment often includes arch bar maxillomandibular fixation (MMF), either alone or in combination with open reduction/internal fixation (ORIF) techniques. The glove perforation rate associated with arch bar placement, the incidence of blood-borne pathogen positivity in facial fracture patients, and the injurious effects of arch bars on dental enamel and gingiva have prompted the development of safer alternatives to arch bar MMF. This study evaluates the efficacy, ease of use, and safety profile of one such alternative: orthodontic direct bonded bracket fixation (MMF/DBB).

STUDY DESIGN

Prospective study of consecutive mandible fracture patients treated with MMF/DBB.

METHODS

Thirty-two patients with mandibular fractures were evaluated from January 1994 to July 1997. Fourteen were appropriate for treatment with MMF/DBB (12 men and two woman; mean age, 24.6+/-7.2 y; range, 16-42 y). Fracture sites included symphysis, angle, condylar neck, coronoid, and body. Nine patients underwent MMF/DBB alone; five underwent MMF/DBB with subsequent ORIF.

RESULTS

No infection, malocclusion, malunion/nonunion, or enamel/ gingiva injury occurred. Mean follow-up was 6 months (range, 1-12 mo). Oral hygiene with MMF/DBB was superior to historical controls using arch bars.

CONCLUSIONS

MMF/DBB can serve as the single treatment method with satisfactory results in patients with favorable, less complicated mandible fractures, although with increased experience, we have treated several more complex cases with MMF/DBB alone. In cases necessitating ORIF, MMF/DBB can be performed preoperatively to align fracture segments and reestablish occlusion. This facilitates placement of osteosynthesis plates and reduces ORIF operative time. MMF/DBB is an economical, safe technique that minimizes blood-borne-pathogen risk to the operative team, eliminates periodontal injury, facilitates postoperative dental hygiene, and is painless to apply and remove.

Cavernous sinus syndrome caused by a primary paranasal sinus non-Hodgkin's lymphoma

Although uncommon, non-Hodgkin's lymphomas occasionally arise from the nose and paranasal sinuses. Rarely, they may invade into the cavernous sinus and produce signs and symptoms that characteristically include unilateral ophthalmoplegia, sensation loss in the distribution of the ophthalmic and other divisions of the trigeminal nerve, sympathetic nerve paralysis and proptosis. In this report, we present a case of cavernous sinus syndrome (CSS) caused by infiltration of non-Hodgkin's lymphoma from the adjacent paranasal sinuses and address issues regarding its diagnosis and treatment.

The failing flap in facial plastic and reconstructive surgery: role of the medicinal leech

OBJECTIVE

To review the use of the medicinal leech, Hirudo medicinalis, in salvaging the failing, venous-congested flap. A protocol for the use of leeches is presented. Four illustrative cases of failing flaps (pectoralis major, midline forehead, and temporalis) are presented.

STUDY DESIGN

Literature review comprised of MEDLINE search 1965 to present. Retrospective review of four cases involving the management of the failing, venous-congested flap.

METHODS

A retrospective review of four cases of failing, venous-congested flaps was performed.

RESULTS

The authors' experience, as well as the data from the reviewed medical literature, demonstrates the importance of early intervention in order to salvage the failing, venous-congested flap. Leeches are an immediate and efficacious treatment option.

CONCLUSIONS

1. Review of the literature indicates that the survival of the compromised, venous-congested flap is improved by early intervention with the medicinal leech. H medicinalis injects salivary components that inhibit both platelet aggregation and the coagulation cascade. The flap is decongested initially as the leech extracts blood and is further decongested as the bite wound oozes after the leech detaches. 2. When a flap begins to fail, salvage of that flap demands early recognition of reversible processes, such as venous congestion. The surgeon must be familiar with the use of leeches and should consider their use early, since flaps demonstrate significantly decreased survival after 3 hours if venous congestion is not relieved. In the four cases presented, a standardized protocol facilitated early leech use and provided for the psychological preparation of the patient, availability of leeches, and an antibiotic prophylaxis regimen. 3. The complications associated with leech use can be minimized with antibiotic therapy, wound care, and hematocrit monitoring. 4. The use of the medicinal leech for salvage of the venous-congested flap is a safe, efficacious, economical, and well-tolerated intervention.

Closed dressings after laser skin resurfacing

OBJECTIVE

To evaluate the safety, efficacy, and patient acceptance of closed dressings after full facial resurfacing with the carbon dioxide laser.

DESIGN

Prospective cohort of men and women undergoing full facial carbon dioxide laser resurfacing.

SETTING

Ambulatory surgical center at a university hospital.

PATIENTS

Forty consecutive patients randomized to 1 of 4 dressing groups.

INTERVENTIONS

All patients underwent full facial resurfacing with a carbon dioxide laser system. One of 5 closed dressings (single- or 3-layer composite foam, plastic mesh, hydrogel, or polymer film) was placed immediately after the procedure. Closed dressings were changed on postoperative day 2 and removed on postoperative day 4.

OUTCOME MEASURES

Objective postoperative criteria of erythema, scarring, reepithelialization, and surface irregularities were recorded and photodocumented. Comparisons were made among the closed dressing groups as well as with a group of historical control subjects treated with open dressings. The ease of application, office time for preparation and application, and cost of the individual dressings were collected. Patient characteristics of overall acceptance, comfort, and ease of maintenance were recorded with a visual analog scale.

RESULTS

There were no complications of scarring, surface irregularities, or contact dermatitis from the application or maintenance of the closed dressings. There were no significant differences in the number of days of postoperative erythema or in the rate of facial reepithelialization among the groups. Most patients preferred not to continue with the closed dressings past 2 days. Positive features from the use of closed dressings included reduction in crust formation, decreased pruritus, decreased erythema, and decreased postoperative pain, compared with historical controls. Negative features included time in preparation and application of the dressings. Costs ranged from $9.79 to $50 per dressing change.

CONCLUSIONS

Closed dressings are safe and offer benefits noted during the first 4 postoperative days. Patients can be expected to maintain a closed dressing for at least 24 hours but no longer than 4 days. The positive features of closed dressings and patient acceptance outweigh the cost and office time involved with their application and maintenance.

Effect of increased inner ear pressure on middle ear mechanics

Velocity of malleus, umbo, and stapes footplate in response to stepwise increases up to +400 mm H2O in hydrostatic pressure of the inner ear was investigated in 10 fresh human temporal bones by using a laser Doppler interferometer. The sound-pressure input was 114 dB SPL, and the frequency range was 0.4 to 5.0 kHz. Static displacement of these sites was also measured by a video measuring system. When the inner ear pressure was increased, the malleus and stapes moved outward. Amplitude of umbo velocity decreased below 1.0 kHz with a slight increase around 2.0 kHz, whereas stapes velocity decreased at all frequencies with the major effect below 1.0 kHz. The phase angle of malleus umbo velocity advanced markedly in response to the increased inner ear pressure between 1.0 and 1.4 kHz. Change in the vibration of the umbo was thought to be primarily caused by an increased stiffness of the middle ear conduction system, and that of the stapes was caused by distention of the annular ligament and increased cochlear impedance produced by the increased inner ear pressure. These changes in TM vibration and its phase angle may help detect indirectly an elevation of inner ear pressure.

Sniffing and smelling: separate subsystems in the human olfactory cortex

The sensation and perception of smell (olfaction) are largely dependent on sniffing, which is an active stage of stimulus transport and therefore an integral component of mammalian olfaction. Electrophysiological data obtained from study of the hedgehog, rat, rabbit, dog and monkey indicate that sniffing (whether or not an odorant is present) induces an oscillation of activity in the olfactory bulb, driving the piriform cortex in the temporal lobe, in other words, the piriform is driven by the olfactory bulb at the frequency of sniffing. Here we use functional magnetic resonance imaging (fMRI) that is dependent on the level of oxygen in the blood to determine whether sniffing can induce activation in the piriform of humans, and whether this activation can be differentiated from activation induced by an odorant. We find that sniffing, whether odorant is present or absent, induces activation primarily in the piriform cortex of the temporal lobe and in the medial and posterior orbito-frontal gyri of the frontal lobe. The source of the sniff-induced activation is the somatosensory stimulation that is induced by air flow through the nostrils. In contrast, a smell, regardless of sniffing, induces activation mainly in the lateral and anterior orbito-frontal gyri of the frontal lobe. The dissociation between regions activated by olfactory exploration (sniffing) and regions activated by olfactory content (smell) shows a distinction in brain organization in terms of human olfaction.

Synthesis and 5 alpha-reductase inhibitory activity of 8-substituted benzo[f]quinolinones derived from palladium mediated coupling reactions

Benzoquinolinones have been shown to be potent, selective inhibitors of the Type I 5 alpha-reductase enzyme, which is responsible for the production of dihydrotestosterone from testosterone localized in the scalp. In an effort to identify compounds that demonstrate inhibition of both 5 alpha-reductase isozymes, we have employed 8-bromobenzoquinolinone as an advanced intermediate for participation in a variety of palladium mediated carbon-carbon bond forming reactions. By varying the 8-substituent it is possible to alter the selectivity profile of the series.

Acoustic effect of malleus head removal and tensor tympani muscle section on middle ear reconstruction

In the reconstruction of ears with a missing incus, an incus replacement prosthesis (IRP) is commonly used to connect malleus and stapes. In some cases, it is necessary to resect the malleus head and/or section the tensor tympani muscle (TTM) tendon. The acoustic effects of these maneuvers have not been well studied. We performed experiments in a temporal bone model to measure the effect of these maneuvers on middle ear sound transmission. Measurements of umbo and stapes displacement were made before and after malleus head removal and TTM section plus incus replacement with an IRP. After malleus head removal, there was a peak gain in stapes displacement of 6 dB below 0.5 kHz and 8 dB above 2.5 kHz. TTM section had a similar but lesser effect. A clinical example is described.

Distortion of the auriculocephalic angle following rhytidectomy. Recognition and prevention

Distortion of ear protrusion after rhytidectomy results in an aesthetically unfavorable appearance. We have seen cases in which the auriculocephalic angle has widened postoperatively, producing a noticeable deformity. Herein, we report 3 cases that resulted in abnormal postsurgical ear protrusion. We also discuss prevention through the use of conchal setback sutures.

Contemporary management of the aging brow and forehead

Management of the aging brow and forehead has recently evolved based on available innovative technologies. Likewise, procedure-specific indications have changed based on collective surgical experiences. No longer is the approach based solely on hair pattern or degree of brow ptosis. Patients require varying combinations of brow elevation (prior to blepharoplasty), correction of brow asymmetries, and hairline-preserving forehead elevation. Some may only require excisional or paralytic procedures of the frontalis muscle (horizontal forehead creases), corrugator supercilii muscles (vertical glabellar furrows), and procerus muscle (horizontal glabellar furrows). We present a 3-year experience using a problem-specific approach. This incorporates endoscopic technology, botulinum toxin type A purified neurotoxin complex (Botox, Allergan, Irvine, CA) intramuscular injection, and traditional procedures such as the coronal, pretrichial, midforehead, and direct browlift. Current indications, patient selection, and results are also discussed.

Effect of middle ear pressure change on middle ear mechanics

The effect of graded variations in middle ear pressure on ossicular vibration was measured in 15 normal human temporal bone specimens. The displacement amplitude of the umbo and stapes head was measured at 16 frequencies between 0.2 kHz and 3.5 kHz at a constant sound pressure of 134 dB SPL at the tympanic membrane (TM) using a non-contacting video measuring system. Both negative and positive pressures decreased umbo and stapes vibration at low frequencies and slightly increased the vibration at higher frequencies. The effects were greater for negative pressure than for positive pressure. The change in stapes vibration was less than that of the umbo at low frequencies, but increased at higher frequencies. In some temporal bones, a small positive pressure produced improvement in stapes vibration at all frequencies. These effects were thought to be primarily due to an increased stiffness of the TM and a damping of ossicular vibration, due to stretching of the ossicular suspensory ligaments and the annular ligament of the footplate.

Scanning laser Doppler vibrometry of the middle ear ossicles

This paper describes measurements of the vibratory modes of the middle ear ossicles made with a scanning laser Doppler vibrometer. Previous studies of the middle ear ossicles with single-point laser Doppler measurements have raised questions regarding the vibrational modes of the ossicular chain. Single-point analysis methods do not have the ability to measure multiple points on the ossicles and, consequently, have limited ability to simultaneously record relative phase information at these points. Using a Polytec Model PSV-100, detailed measurements of the ossicular chain have been completed in the human temporal bone model. This model, when driven with a middle ear transducer, provides detailed three-dimensional data of the vibrational patterns of the middle ear ossicles. Implications for middle ear implantable devices are discussed.

Serum-free keloid fibroblast cell culture: an in vitro model for the study of aberrant wound healing

The purpose of this study was to develop an in vitro serum-free keloid fibroblast model. Keloid formation remains a problem for every surgeon. Prior evaluations of fibroblast characteristics in vitro, especially those of growth factor measurement, have been confounded by the presence of serum-containing tissue culture media. The serum itself contains growth factors, yet has been a "necessary evil" to sustain cell growth. The design of this study is laboratory-based and uses keloid fibroblasts obtained from five patients undergoing facial (ear lobule) keloid removal in a university-affiliated clinic. Keloid fibroblasts were established in primary cell culture and then propagated in a serum-free environment. The main outcome measures included sustained keloid fibroblast growth and viability, which was comparable to serum-based models. The keloid fibroblast cell cultures exhibited logarithmic growth, sustained a high cellular viability, maintained a monolayer, and displayed contact inhibition. Demonstrating model consistency, there was no statistically significant difference between the mean cell counts of the five keloid fibroblast cell lines at each experimental time point. The in vitro growth of keloid fibroblasts in a serum-free model has not been done previous to this study. The results of this study indicate that the proliferative characteristics described are comparable to those of serum-based models. The described model will facilitate the evaluation of potential wound healing modulators, and cellular effects and collagen modifications of laser resurfacing techniques, and may serve as a harvest source for contaminant-free fibroblast autoimplants. Perhaps its greatest utility will be in the evaluation of endogenous and exogenous growth factors.

Patient selection in the treatment of glabellar wrinkles with botulinum toxin type A injection

OBJECTIVES

To determine the dose-response characteristics and side-effects profile of Clostridium botulinum type A exotoxin (Botox) used to treat glabellar wrinkles and develop guidelines for patient selection based on the nature and severity of the treated wrinkles.

DESIGN

Prospective, nonrandomized pilot and electromyogram (EMG)-guided studies.

SETTING

Two ambulatory care clinics at university hospitals.

PARTICIPANTS

For the pilot study, volunteer samples of 23 patients with glabellar wrinkles; for the EMG-guided study, volunteer samples of 57 patients with glabellar wrinkles.

INTERVENTIONS

For the pilot study, 23 patients were serially injected with up to 10.0 mouse units (MU) of Botox into each corrugator muscle; for the EMG-guided study, 57 patients were injected under EMG guidance with an initial dose of 10.0 MU of Botox into each corrugator muscle. Eleven patients with persistent corrugator activity were reinjected with 10.0 MU of Botox.

MAIN OUTCOME MEASURES

For the pilot study, slide photographs were obtained before and 2 weeks after injection; for the EMG-guided study, slide photographs were obtained before and at 2 weeks and at 2 months after injection. Patients were asked to evaluate results numerically.

RESULTS

For the pilot study, injection of up to 10.0 MU of Botox into each corrugator muscle produced a satisfactory improvement in 12 patients; for the EMG-guided study, 43 patients were satisfied with improvement after full abolition of corrugator or accessory lateral brow muscle activity. Women were more likely to achieve satisfactory results than were men (80% [40/50] vs 43% [3/7]; P < or = .03). Improvement was not age related. No significant side effects or complications were observed.

CONCLUSIONS

Glabellar wrinkles may be satisfactorily treated with Botox injection into the corrugator supercilii muscles. Improvement is temporary, dose dependent, and may not be seen in some patients even with successful denervation of the treated muscles. Clinicians may begin treatment with a dose of 10.0 MU of Botox into each corrugator muscle, and may select candidates for injection by determining the type of wrinkle to be treated and its spreadability (glabellar spread test).

Transcalvarial suture fixation for endoscopic brow and forehead lifts

OBJECTIVE

To evaluate the safety and effectiveness of transcalvarial suture fixation during endoscopic repair of brow ptosis.

DESIGN

Case series.

SETTINGS

A private ambulatory surgicenter and a Veterans Affairs Hospital.

PARTICIPANTS

Fifty patients with brow ptosis with minimum follow-up of 12 months.

RESULTS

Patients had improvement in brow position in all cases. There were no adverse effects of performing cortical tunnels and suture fixation.

CONCLUSION

Transcalvarial suture fixation can be performed safely with good to excellent results and avoids the need for screw or plate fixation.

Surgical morbidity of neck dissection after chemoradiotherapy in advanced head and neck cancer

The use of chemotherapy and irradiation for organ preservation attempts to eliminate the need for extensive surgery in patients with advanced squamous cell carcinoma of the head and neck (SCCHN). We sought to characterize the morbidity of surgery in patients who needed surgery after treatment with induction chemotherapy followed by simultaneous chemotherapy and radiotherapy (chemoradiotherapy). The surgical morbidity within the first 30 postoperative days of 17 patients treated in an organ preservation approach between July 1991 and December 1994 was compared with a control group of patients undergoing similar surgical procedures during the same period. The organ preservation study patients underwent surgical procedures consisting of 18 neck dissections and 5 resections of the primary site. Six patients in the organ preservation study group experienced 8 surgical complications within the first 30 postoperative days, and most complications were minor. There was no significant difference in the duration of surgery or length of hospitalization between study patients and matched controls. Our surgical complication rate (35.3%) was higher but not statistically different from that of the control group, and compared favorably to reports of surgical morbidity (44% to 61%) in the literature on patients treated with chemoradiotherapy. The lower complication rate seen in this study may be a reflection of early surgical intervention as part of our organ preservation study scheme, the preponderance of neck dissections performed, and the limited number of pharyngeal procedures performed.

Laser Doppler vibrometer (LDV)--a new clinical tool for the otologist

We describe a laser Doppler system (LDS) that can be used clinically for the measurement of tympanic membrane (TM), malleus and prosthesis head displacement in response to sound inputs of 80-to 100-dB sound-pressure level (SPL). It also has the potential for use in the operating room to perform measurements of prosthesis and stapes displacement. The information provided by such testing gives the otologist knowledge of TM and ossicular function that is unique in evaluating middle ear function; it should help select the best type of reconstruction in a given case and direct us toward new and better methods of TM and ossicular reconstruction. The results of umbo displacement measurements in 95 human ears are reported. Examples are provided of LDS measurements in representative ears and how they can be of help to the clinician. The potential of multisite TM-displacement testing is demonstrated in two temporal bones, including before and after partial ossicular replacement prosthesis (PORP) insertion.

Combined use of superpulsed carbon dioxide laser and cryotherapy for treatment of facial rhytids

OBJECTIVE

To compare the effect of superpulsed carbon dioxide (CO2) laser alone with that of cryotherapy in combination with CO2 laser in treatment of facial rhytids.

DESIGN

A randomized prospective study.

SETTING

Facial Plastic Surgery Clinic at Standford University Medical Center, Standford, Calif.

PATIENTS

Twenty patients with perioral rhytids were randomized in the study, 11 in the laser group and 9 in the cryotherapy and laser group.

INTERVENTION

Patients in the laser group were treated with superpulsed CO2 laser. Initially, the shoulders of rhytids were spot treated. The area was then wiped and rehydrated. The entire surface was then treated with a second pass. A third pass, if deemed necessary, was then used to treat the shoulders. Patients in the combined group underwent cryotherapy of the entire perioral region followed by CO2 laser treatment similar to that previously described.

MAIN OUTCOME MEASURE

Improvement in facial rhytids with laser treatment alone was compared with improvement using cryotherapy and laser. A skin wrinkle grading system was used and patients were graded by 3 independent observers. Close-up photographs were obtained preoperatively and postoperatively. A questionnaire was filled out by each patient 1 month following treatment and was used to rate overall patient satisfaction.

RESULTS

There was no statistically significant difference between the 2 groups regarding final outcome, amount of anesthetic agents required for each patient, or rate of complications.

CONCLUSION

Superpulsed CO2 skin resurfacing alone is as effective as combined cryotherapy and superpulsed CO2 laser for treatment of perioral rhytids.

Characterization of type I 5 alpha-reductase activity in DU145 human prostatic adenocarcinoma cells

The conversion of testosterone (T) to dihydrotestosterone (DHT) has been demonstrated to be catalysed by at least two isoforms of human steroid 5 alpha-reductase, designated types I and II. Type II 5 alpha-reductase expression predominates in human accessory sex tissues, localized to the fibromuscular stromal compartment. The type I isoform predominates in skin, prostatic epithelia and, to a lesser extent, in prostatic fibromuscular stroma. The significance of the type I isoform to prostatic cellular growth and function remains undefined. In cultured DU145 cells, we evaluated the metabolism of [14C]-T and demonstrated the time-dependent formation of [14C]-DHT. Oxidative metabolism (conversion of [14C]-T to [14C]-androstenedione) and the formation of conjugated androgen metabolites occurred at a relatively low rate in the DU145 cells. Using human type I 5 alpha-reductase cDNA, Northern blot analysis of DU145 cell mRNA revealed high levels of type I isoform expression. Analogous probing of the DU145 cells with a human 5 alpha-reductase II cDNA failed to reveal expression of the type II isoform. The expression of functional type I activity has been confirmed pharmacologically using isoform-selective 5 alpha-reductase inhibitors. Reductive metabolism of [3H]-T in the DU145 cells was inhibited in a concentration-dependent manner by LY306089, a potent non-steroidal type I-selective inhibitor (IC50 = 10.0 nM). SKF105657, a steroidal type II-specific inhibitor was distinctly less active at inhibiting [3H]-DHT formation. LY306089 was a non-competitive inhibitor of type I 5 alpha-reductase in DU145 cellular homogenates with an apparent Ki value of 4.0 nM. These studies have identified and pharmacologically defined type I 5 alpha-reductase activity in an androgen-insensitive prostatic cancer cell line and provide the basis for additional investigations into the significance of type I 5 alpha-reductase to human prostatic pathophysiology.

Power Microdebrider for Functional Endoscopic Sinus Surgery

Associate Editors Note: Readers should be aware that since the acceptance of this manuscript into our system, other companies have made available microdebriders. These companies include Linvotec and Xomed-Treace. These microdebriders present a variety of features, which may include bendable router blades, a variety of different levels of “aggressiveness” of router blades, automatic irrigation systems, suction adjustment valves, and a variety of motor sizes providing power for the units. Surgeons wishing to optimize their individual needs for their patient populations should be aware of differences and the assortment of microdebriders available.

Responses of LNCaP prostatic adenocarcinoma cell cultures to LY300502, a benzoquinolinone human type I 5alpha-reductase inhibitor

We evaluate the metabolic inhibitory, antiproliferative, and antisecretory effects of LY300502, a benzoquinolinone human-specific type I-selective steroid 5alpha-reductase inhibitor in LNCaP human prostatic adenocarcinoma cell cultures. Reductive metabolism of [3H-T] in the LNCaP cells was inhibited in a concentration-dependent manner by LY300502 (IC50 approximately 5.77 nM). The proliferative responses of LNCaP cells to LY300502 were examined in the presence of 0.1 NM testosterone (T), a concentration that stimulates maximal LNCaP cell numbers 40% above control levels. LY300502 significantly anatagonized T-induced stimulation of LNCaP cellular proliferation at concentrations greater that 10 nM (P<0.05), and at 1,000 nMcompletely blocked the mitogenic effects of T on LNCaP cells. In the absence of androgen, LY300502 had no effect on LNCaP cellular proliferation. In the presence of 100 nM T, an androgen concentration that maximally stimulates in vitro PSA production, LY300502 significantly antagonized T-induced PSA secretion at a concentration equal to or greater than 30 nM (P<0.05). These studies provide the basis for additional investigations into the pathophysiologic significance of type I 5alpha-reductase to prostatic cancer and the potential utility of selective inhibitors as therapeutic agents.

Sound Pressure Gain Produced by the Human Middle Ear

The acoustic function of the middle ear is to match sound passing from the low impedance of air to the high impedance of cochlear fluid. Little information is available on the actual middle ear pressure gain in human beings. This article describes experiments on middle ear pressure gain in six fresh human temporal bones. Stapes footplate displacement and phase were measured with a laser Doppler vibrometer before and after removal of the tympanic membrane, malleus, and incus. Acoustic insulation of the round window with clay was performed. Umbo displacement was also measured before tympanic membrane removal to assess baseline tympanic membrane function. The middle ear has its major gain in the lower frequencies, with a peak near 0.9 kHz. The mean gain was 23.0 dB below 1.0 kHz, the resonant frequency of the middle ear; the mean peak gain was 26.6 dB. Above 1.0 kHz, the sound pressure gain decreased at a rate of −8.6 dB/octave, with a mean gain of 6.5 dB at 4.0 kHz. Only a small amount of gain was present above 7.0 kHz. Significant individual differences in pressure gain were found between ears that appeared related to variations in tympanic membrane function and not to variations in cochlear impedance.

Raloxifene (LY156758) produces antimetastatic responses and extends survival in the PAIII rat prostatic adenocarcinoma model

The benzothiophene antiestrogen, raloxifene (LY156758), has selective estrogen pharmacological antagonist activity in rats. The PAIII rat prostatic adenocarcinoma model was used to evaluate the effects of this agent on the lymphatic and pulmonary metastasis and survival in tumor-bearing male Lobund-Wistar (LW) rats. Raloxifene was inactive against colony formation of PAIII cells in vitro. Similarly, following subcutaneous (s.c.) implantation of 10(6) PAIII cells in the tail, s.c. administration of raloxifene (2.0, 10.0, or 20.0 mg/kg/day) for 30 days failed to demonstrate cytoreductive activity against primary tumor growth in the tail. However, in these same animals, raloxifene administration produced significant (P < 0.05) inhibition of PAIII metastasis from the primary tumor in the tail to the gluteal and iliac lymph nodes (maximal responses = 89% and 81% from control values, respectively). PAIII metastasis to the lungs was significantly inhibited by raloxifene treatment. Numbers of pulmonary foci in PAIII-bearing rats were significantly (P < 0.05) reduced by raloxifene administration in a dose-related manner (maximal reduction = 97% from control values). In these animals, maximal regression of 20% for ventral prostate and 21% for seminal vesicle were also seen after raloxifene administration (P < 0.05 for both). Coadministration of E2B and raloxifene had no consistent antagonistic effect upon the antitumor responses produced by raloxifene. Raloxifene (40.0 mg/kg/day for 28 days) produced marked decreases in PAIII metastasis in the lymphatic and pulmonary components. Continued administration of the compound produced significant (P < 0.05) extension of survival of PAIII-bearing rats. Further studies are needed to define the maximal antitumor efficacy and the mechanism of action of raloxifene in urogenital solid tumor animal models. These data support the contention that raloxifene represents a class of active antimetastatic agents with potential efficacy in the treatment of hormone-insensitive human prostatic cancer.

Sound pressure gain produced by the human middle ear

The acoustic function of the middle ear is to match sound passing from the low impedance of air to the high impedance of cochlear fluid. Little information is available on the actual middle ear pressure gain in human beings. This article describes experiments on middle ear pressure gain in six fresh human temporal bones. Stapes footplate displacement and phase were measured with a laser Doppler vibrometer before and after removal of the tympanic membrane, malleus, and incus. Acoustic insulation of the round window with clay was performed. Umbo displacement was also measured before tympanic membrane removal to assess baseline tympanic membrane function. The middle ear has its major gain in the lower frequencies, with a peak near 0.9 kHz. The mean gain was 23.0 dB below 1.0 kHz, the resonant frequency of the middle ear; the mean peak gain was 26.6 dB. Above 1.0 kHz, the second pressure gain decreased at a rate of -8.6 dB/octave, with a mean gain of 6.5 dB at 4.0 kHz. Only a small amount of gain was present above 7.0 kHz. Significant individual differences in pressure gain were found between ears that appeared related to variations in tympanic membrane function and not to variations in cochlear impedance.

Measurements of the stapes superstructure

Ten human stapes from fresh temporal bones were measured to obtain relevant distances of the stapes superstructure. The dimensions of the parts of the superstructure are as follows: 1) stapes head 1.14 mm (range, 0.91 to 1.49) in diameter parallel to the axis of the footplate and 0.83 mm (range, 0.65 to 1.08) perpendicular to it; 2) stapes head to shoulders 0.93 mm (range, 0.81 to 1.07), head to foramen 1.26 mm (range, 1.15 to 1.39), and head to lateral surface of stapes footplate 3.19 mm (range, 2.91 to 3.45); 3) neck width parallel to the axis of the footplate 1.18 mm (range, 0.88 to 1.47) and 0.64 mm (range, 0.48 to 0.88) perpendicular to it; 4) anterior crus 0.58 mm wide (range, 0.41 to 0.74) at the shoulder of the arch and 0.51 mm (range, 0.39 to 0.65) closer to the stapes footplate; 5) posterior crus 0.65 mm wide (range, 0.46 to 0.77) at the shoulder of the arch and 0.55 mm (range, 0.38 to 0.75) closer to the stapes footplate; and 6) maximum width of entire superstructure near footplate 2.48 mm (range, 2.06 to 2.98).

Treatment of tympanic membrane retraction with the holmium laser

Politzerization, the Valsalva maneuver, and ventilation tube insertion are available treatments for tympanic membrane retraction. Ventilation of the middle ear cavity can correct tympanic membrane retraction in many cases, but not in all. Retraction may be localized or diffuse. This article describes experiments performed to evaluate a new method to "tighten" retracted or flaccid tympanic membranes with a holmium laser in a human temporal bone model. Ten temporal bones with mild-to-moderate retraction of the posterior superior quadrant or pars flaccida were treated with a series of laser pulses around and to the area of retraction. Umbo displacement before and after laser treatment was performed with a laser Doppler vibrometer to evaluate the effect on the acoustic function of the tympanic membrane. In all ears, the posterior superior quadrant retraction appeared to be completely corrected. Laser treatment of the posterior superior quadrant retraction produced improvement in umbo displacement below 1.0 kHz. After treatment of pars flaccida retraction, the configuration was improved a small amount; however, no increase in umbo displacement was found.

The history and development of the implantable hearing aid

Implantable hearing aids have an interesting and colorful history. These devices have usually been investigational, but this has changed. Currently, several implantable devices are available for ongoing clinical trials in humans. They have promise in providing improved hearing in certain cases of conductive, mixed, and sensorineural hearing loss.

Current status and future of implantable electromagnetic hearing aids

Partially implantable electromagnetic hearing aids have several potential advantages over conventional hearing aids. As conventional hearing aids improve in the quality of sound they deliver, however, the role of implant aids must be redefined. One area where they may provide the most benefit is in patients with moderate to severe hearing loss.

The TMJ-ear connection

This article documents the existence of three structures that traverse through the petrotympanic fissure. These structures are the mandibular malleolar ligament, the chorda tympani nerve and the anterior tympanic artery. The mandibular malleolar ligament or the disk-malleolar ligament originates on the anterior process of the mallous. It traverses through the petro-tympanic fissure and attaches to the posterior portion of the capsule and disk of the temporomandibular joint. The chorda tympani nerve supplies sensory feeling to the posterior two thirds of the tongue. The anterior tympanic artery supplies blood to the area of the tympanic membrane. Clinical experience with implants that impinge or cover ear problems and other symptoms. Removal of these implants and placements with devices that do not cover these structures often relieve these symptoms.

Prenatal in vivo bulbourethral gland development is not affected by prostaglandin E2 inhibition

Investigation of bulbourethral gland (BUG) development is useful to study genitourinary (GU) tract growth and differentiation. Understanding GU tract growth and differentiation is relevant to testing the hypothesis that the initial lesion of human benign prostatic hyperplasia involves focal re-expression of inductive processes in the periurethral region of the prostatic transitional zone. Prostaglandins play a role in regulating growth and morphogenesis of different organ systems. Previous reports have proposed that prostaglandin E2 (PgE2) mediates the masculinizing effects of testosterone in the developing neonatal male GU tract. We have previously shown that androgens lower rather than raise BUG PgE2 levels. Further studies led us to conclude that PgE2 does not play a major role in postnatal BUG growth and morphogenesis in vitro. In order to investigate the possible role of PgE2 in prenatal BUG development, indomethacin (INDO, 1.0 mg/kg- day, subcutaneously) was administered to pregnant BALB/c mice on gestational days 12-18. Control pregnant mice were either untreated or injected with dimethylsulfoxide vehicle. Anogenital distances were measured within 12 hours after birth in male and female offspring on day 19. In male neonatal mice, BUGs were examined histologically and PgE2 levels were measured by radioimmunoassay in BUGs and whole genital tracts. We observed no significant morphological differences in INDO-exposed BUGs compared to controls. No significant differences in mean anogenital distances of INDO-exposed male offspring or controls were detected. Mean anogenital distances of female offspring were similar in the three respective groups. Mean BUG PgE2 levels in INDO-exposed neonates were significantly lower (P < 0.05) than in untreated neonates.(ABSTRACT TRUNCATED AT 250 WORDS)