Rare Giant Infected Intradiploic Skull Epidermoid Cysts

Infections associated with giant intradiploic cranial epidermoid cysts are rare. This case report describes the successful surgical management of a 71-year-old diabetic man with a giant intradiploic cranial epidermoid cyst associated with a secondary infection. The patient underwent successful resection of the infected lesion with washout, debridement, and obliteration of the eustachian canal and external auditory canal. At the six-month follow-up, the infection was resolved and the patient was doing well clinically. Intradiploic epidermoid cysts are rare, and the presence of a superimposed otogenic infection is exceptionally rare and infrequently reported in the neurosurgical literature.

Perioperative Complication Profile of Skull Base Meningioma Resection in Older versus Younger Adult Patients

Objectives To better understand the risk-benefit profile of skull base meningioma resection in older patients, we compared perioperative complications among older and younger patients.

Design Present study is based on retrospective outcomes comparison.

Setting The study was conducted at a single neurosurgery institute at a quaternary center.

Participants All older (age ≥ 65 years) and younger (<65 years) adult patients treated with World Health Organization grade 1 skull base meningiomas (2008–2017).

Main Outcome Measures Perioperative complications and patient functional status are the primary outcomes of this study.

Results The analysis included 287 patients, 102 older and 185 younger, with a mean (standard deviation [SD]) age of 72 (5) years and 51 (9) years (p < 0.01). Older patients were more likely to have hypertension (p < 0.01) and type 2 diabetes mellitus (p = 0.01) but other patient and tumor factors did not differ (p ≥ 0.14). Postoperative medical complications were not significantly different in older versus younger patients (10.8 [11/102] vs. 4.3% [8/185]; p = 0.06) nor were postoperative surgical complications (13.7 [14/102] vs. 10.8% [20/185]; p = 0.46). Following anterior skull base meningioma resection, diabetes insipidus (DI) was more common in older versus younger patients (14 [5/37] vs. 2% [1/64]; p = 0.01). Among older patients, a decreasing preoperative Karnofsky performance status score independently predicted perioperative complications by logistic regression analysis (p = 0.02). Permanent neurologic deficits were not significantly different in older versus younger patients (12.7 [13/102] vs. 10.3% [19/185]; p = 0.52).

Conclusion The overall perioperative complication profile of older and younger patients was similar after skull base meningioma resection. Older patients were more likely to experience DI after anterior skull base meningioma resection. Decreasing functional status in older patients predicted perioperative complications.

Combining Stereoscopic Video and Virtual Reality Simulation to Maximize Education in Lateral Skull Base Surgery

Mastery of lateral skull base (LSB) surgery requires thorough knowledge of complex, 3-dimensional (3D) microanatomy and techniques. While supervised operation under binocular microscopy remains the training gold standard, concerns over operative time and patient safety often limit novice surgeons’ stereoscopic exposure. Furthermore, most alternative educational resources cannot meet this need. Here we present proof of concept for a tool that combines 3D-operative video with an interactive, stereotactic teaching environment. Stereoscopic video was recorded with a microscope during translabyrinthine approaches for vestibular schwannoma. Digital imaging and communications in medicine (DICOM) temporal bone computed tomography images were segmented using 3D-Slicer. Files were rendered using a game engine software built for desktop virtual reality. The resulting simulation was an interactive immersion combining a 3D operative perspective from the lead surgeon’s chair with virtual reality temporal bone models capable of hands-on manipulation, label toggling, and transparency modification. This novel tool may alter LSB training paradigms.

Integrating Stereoscopic Video with Modular 3D Anatomic Models for Lateral Skull Base Training

Introduction  Current virtual reality (VR) technology allows the creation of instructional video formats that incorporate three-dimensional (3D) stereoscopic footage.Combined with 3D anatomic models, any surgical procedure or pathology could be represented virtually to supplement learning or surgical preoperative planning. We propose a standalone VR app that allows trainees to interact with modular 3D anatomic models corresponding to stereoscopic surgical videos. Methods  Stereoscopic video was recorded using an OPMI Pentero 900 microscope (Zeiss, Oberkochen, Germany). Digital Imaging and Communications in Medicine (DICOM) images segmented axial temporal bone computed tomography and each anatomic structure was exported separately. 3D models included semicircular canals, facial nerve, sigmoid sinus and jugular bulb, carotid artery, tegmen, canals within the temporal bone, cochlear and vestibular aqueducts, endolymphatic sac, and all branches for cranial nerves VII and VIII. Finished files were imported into the Unreal Engine. The resultant application was viewed using an Oculus Go. Results  A VR environment facilitated viewing of stereoscopic video and interactive model manipulation using the VR controller. Interactive models allowed users to toggle transparency, enable highlighted segmentation, and activate labels for each anatomic structure. Based on 20 variable components, a value of 1.1 × 10 ¹² combinations of structures per DICOM series was possible for representing patient-specific anatomy in 3D. Conclusion  This investigation provides proof of concept that a hybrid of stereoscopic video and VR simulation is possible, and that this tool may significantly aid lateral skull base trainees as they learn to navigate a complex 3D surgical environment. Future studies will validate methodology.

Transtemporal Suprajugular Approach with Neck Dissection for Jugular Foramen Tumor Resection: Operative Video

This video demonstrates the transmastoid suprajugular approach with neck dissection to a solitary fibrous tumor involving the jugular foramen and upper cervical region. This patient was a 39-year-old man who presented with dysphagia and cranial nerve (CN) XI and CN XII palsies. Imaging revealed a large homogenously enhancing lesion involving the jugular foramen and extending into the retropharyngeal space ( Fig. 1 ). Radiographic findings supported a diagnosis of jugular foramen schwannoma. After an initial period of observation, the tumor demonstrated significant growth, and the patient agreed to proceed with surgery. The suprajugular approach allowed for exposure and resection of the tumor without mobilization of the facial nerve. The patient had an excellent clinical outcome with House–Brackmann grade-1 facial function, safely tolerated a regular diet, had intact CN XI function, and had a stable CN XII palsy ( Fig. 2 ). Pathology findings identified the tumor as a hemangiopericytoma World Health Organization grade 1 (solitary fibrous tumor).

The link to the video can be found at: https://youtu.be/C4sPyHcLMA0 .

Three-Dimensional Printed Models for Lateral Skull Base Surgical Training: Anatomy and Simulation of the Transtemporal Approaches

BACKGROUND

Three-dimensional (3D) printing holds great potential for lateral skull base surgical training; however, studies evaluating the use of 3D-printed models for simulating transtemporal approaches are lacking.

OBJECTIVE

To develop and evaluate a 3D-printed model that accurately represents the anatomic relationships, surgical corridor, and surgical working angles achieved with increasingly aggressive temporal bone resection in lateral skull base approaches.

METHODS

Cadaveric temporal bones underwent thin-slice computerized tomography, and key anatomic landmarks were segmented using 3D imaging software. Corresponding 3D-printed temporal bone models were created, and 4 stages of increasingly aggressive transtemporal approaches were performed (40 total approaches). The surgical exposure and working corridor were analyzed quantitatively, and measures of face validity, content validity, and construct validity in a cohort of 14 participants were assessed.

RESULTS

Stereotactic measurements of the surgical angle of approach to the mid-clivus, residual bone angle, and 3D-scanned infill volume demonstrated comparable changes in both the 3D temporal bone models and cadaveric specimens based on the increasing stages of transtemporal approaches (PANOVA <.003, <.007, and <.007, respectively), indicating accurate representation of the surgical corridor and working angles in the 3D-printed models. Participant assessment revealed high face validity, content validity, and construct validity.

CONCLUSION

The 3D-printed temporal bone models highlighting key anatomic structures accurately simulated 4 sequential stages of transtemporal approaches with high face validity, content validity, and construct validity. This strategy may provide a useful educational resource for temporal bone anatomy and training in lateral skull base approaches.

Canal reconstruction mastoidectomy: Outcomes comparison following primary versus secondary surgery

OBJECTIVES/HYPOTHESIS

Compare surgical and audiometric outcomes following canal wall reconstruction (CWR) tympanomastoidectomy used as a primary versus secondary approach for treating cholesteatoma.

STUDY DESIGN

Retrospective.

METHODS

Patients treated for primary/secondary cholesteatoma from 2006 to 2017 via CWR were included if they had preoperative/postoperative audiograms, detailed operative note(s), and >12 months' follow-up. Patients were stratified by previous surgical history into two groups: primary CWR group (PG) and secondary CWR group (SG). Surgical outcomes measured were prevalence of recidivistic cholesteatoma, canal cholesteatoma, revision rate, and canal wall down (CWD) conversion rates. Secondary outcomes were prevalence of infection, external canal adhesions/stenoses, and retractions. Audiometric outcomes included change in pure-tone average and air-bone gap.

RESULTS

We stratified 45 patients/ears into the PG and 26 into the SG. The groups did not significantly differ in age, sex, or smoking status. Overall, median follow-up was 35 months. SG patients had higher rates of cholesteatoma detected at staged surgery than did PG patients (P = .04). However, these patients exhibited lower rates of open revision surgery (4% vs.13%) and a significant improvement in air-bone gap (P = .004). Three PG patients (7%) required conversion to CWD versus zero SG patients. Secondary outcomes were similar. Patients who underwent delayed staging >12 months from CWR had increased rates of recidivism and canal adhesion/stenosis.

CONCLUSIONS

CWR was effective for treating cholesteatoma as both a primary and secondary surgical approach. SG patients experienced higher rates of recidivism and secondary canal cholesteatoma. PG patients had higher rates of revision surgery. Staging of ears undergoing CWR is important regardless of prior surgical history.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:2580-2587, 2019.

Middle Fossa Approach for Resection of Vestibular Schwannomas: A Decade of Experience

BACKGROUND

The middle cranial fossa (MCF) approach is a challenging surgical technique for the resection of small and intermediate sized, primarily intracanalicular, vestibular schwannomas (VS), with the goal of hearing preservation (HP).

OBJECTIVE

To describe a decade-long, single institutional experience with the MCF approach for resection of VS.

METHODS

This is a retrospective cohort study of 63 patients who underwent the MCF approach for resection of VS from 2006 to 2016. Audiometric data included pure-tone average (PTA), low-tone pure-tone average (LtPTA), word recognition score, and American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification at presentation and follow-up. Patients with postoperative serviceable (AAO-HNS class A-B) and/or useful (AAO-HNS class A-C) hearing were compared to those without HP. Facial nerve function was assessed using the House–Brackmann scale.

RESULTS

The mean age and duration of follow-up were 50 ± 13 yr and 21 ± 21 mo, respectively. The mean tumor size was 10 ± 4 mm. The serviceable and usable HP rates were 54% and 50%, respectively. Some residual hearing was preserved in 71% of patients. Large tumor size (P = .05), volume (P = .03), and extrameatal tumor extension (P = .03) were associated with poor audiometric outcomes. The presence of a fundal fluid cap (P = .01) was a favorable finding. At definitive testing, LtPTA was significantly better preserved than traditional PTA (P = .01). Facial nerve outcomes, tumor control rates, and durability of audiometric outcomes were excellent. 47% of patients pursued aural rehabilitation.

CONCLUSION

In our series, the MCF approach for VS provided excellent rates of tumor and facial nerve function, with durable serviceable HP.

Are Patients with Spontaneous CSF Otorrhea and Superior Canal Dehiscence Congenitally Predisposed to Their Disorders?

Objectives (1) Compare lateral skull base (LSB) height/thickness in patients with spontaneous cerebrospinal fluid otorrhea (CSF), superior canal dehiscence (SCD), acoustic neuromas (AN), and otosclerosis (OTO). (2) Perform correlations between age, body mass index (BMI), sex, and LSB height/thickness. Study Design Case series with chart review. Setting Tertiary referral center. Subjects and Methods Patients with CSF, SCD, AN, and OTO diagnosed from 2006 to 2016 were included if they had high-definition temporal bone computed tomography (CT) and absence of trauma, radiation, chronic ear disease, and/or congenital anomaly. CT-based measurements included LSB height/thickness and pneumatization rates overlaying the external auditory canal (EAC), tegmen tympani (TgT), perigeniculate region (PG), and internal auditory canal (IAC). LSB height/thickness, age, sex, and BMI were statistically correlated. In total, 256 patients and 493 ears (109 CSF, 115 SCD, 269 AN/OTO) were measured. Results Patients with CSF had significantly higher BMIs than the other groups ( P < .001). Patients with CSF and SCD had similar radiographic LSB phenotypes at most measured locations. Both groups exhibited a significantly lower LSB height compared to the AN and OTO groups (mean, 3.9-4.2 mm vs 4.9-5.6 mm; P < .001). Patients with CSF and SCD also demonstrated significantly lower pneumatization rates, as low as 17% to 23% overlaying the PG and IAC ( P < .001). There were no statistically significant correlations found between age, sex, BMI, and LSB height/thickness at any measurement location in any group. Conclusions Patients with CSF and SCD exhibit similar radiographic LSB phenotypes. Age, sex, and BMI do not significantly correlate with LSB height/thickness. These data support the theory that CSF and SCD arise via similar congenital pathoetiologic mechanisms.

Facial Palsy Following Embolization of a Juvenile Nasopharyngeal Angiofibroma

Objectives:

To describe a case of the rare complication of facial palsy following preoperative embolization of a juvenile nasopharyngeal angiofibroma (JNA). To illustrate the vascular supply to the facial nerve and as a result, highlight the etiology of the facial nerve palsy.

Methods:

The angiography and magnetic resonance (MR) imaging of a case of facial palsy following preoperative embolization of a JNA is reviewed.

Results:

A 13-year-old male developed left-sided facial palsy following preoperative embolization of a left-sided JNA. Evaluation of MR imaging studies and retrospective review of the angiographic data suggested errant embolization of particles into the petrosquamosal branch of the middle meningeal artery (MMA), a branch of the internal maxillary artery (IMA), through collateral vasculature. The petrosquamosal branch of the MMA is the predominant blood supply to the facial nerve in the facial canal. The facial palsy resolved since complete infarction of the nerve was likely prevented by collateral blood supply from the stylomastoid artery.

Conclusions:

Facial palsy is a potential complication of embolization of the IMA, a branch of the external carotid artery (ECA). This is secondary to ischemia of the facial nerve due to embolization of its vascular supply. Clinicians should be aware of this potential complication and counsel patients accordingly prior to embolization for JNA.

Radiographic Evidence of Occult Intracranial Hypertension in Patients with Ménière’s Disease

Objectives

(1) Describe the prevalence of radiographic signs of intracranial hypertension (ICH) in Ménière’s disease (MD) and (2) compare the prevalence of radiographic signs of ICH in MD patients managed medically to those managed surgically.

Study Design

Case-control study.

Setting

Academic neurotologic practice.

Subjects and Methods

Adult MD patients (aged ≥17 years) treated from 2011 to 2015 were reviewed. Inclusion required magnetic resonance imaging (MRI) of the head and follow-up >6 months. Patients with intracranial tumors, mass effect, trauma, previous intracranial surgery, and glaucoma were excluded. MD patients were separated by administered treatment into medical and surgical subgroups. Cochlear implant (CI) recipients served as radiographic controls. Eighty-four MD patients (46 surgical, 38 medical) and 37 CI controls were assessed. MRI measurements assessed for empty/partial sella (ES/PS), dilated/tortuous optic nerve sheath (ONS), and posterior globe flattening (PGF).

Results

Mean age was 53.8 ± 1.3 years and median body mass index (BMI) was 28.2 kg/m2. Of the patients, 64% were female and 92% were white. MRI findings in the MD cohort were as follows: ES/PS, 46.4%; ONS change, 42.8%; and PGF, 8.3%. The prevalence of ONS change was higher in MD patients than in controls (42.8% vs 13.5%, P = .003). The surgical MD group had higher prevalence of ONS change (52%) compared with the medical group (31.5%, P = .05) and controls (13.5%, P = .0004). The surgical group had a higher prevalence of ≥2 simultaneous MRI findings compared with medical MD patients (39% vs 10%, P = .01) and controls (14%, P = .01).

Conclusion

MD patients demonstrate a high prevalence of radiographic signs of ICH. MD patients who required surgery had a greater prevalence of radiographic signs of ICH compared with non-MD patients and medically managed MD patients.

Idiopathic intracranial hypertension: Contemporary review and implications for the otolaryngologist

OBJECTIVES

1) Review controversies pertaining to the pathophysiology, diagnosis, and treatment of idiopathic intracranial hypertension. 2) Discuss the evolving role of otolaryngologists in managing this disease and related disorders.

DATA SOURCES

Primary literature review, Centers for Disease Control and Prevention website, International Classification of Headache Disorders, Second Edition.

METHODS

A comprehensive review of the primary literature was performed from 1990 to 2016 utilizing keywords idiopathic intracranial hypertension, pseudotumor cerebri, benign intracranial hypertension, spontaneous cerebrospinal fluid leak, and encephalocele. Articles were included at the discretion of the authors based on novel and/or historical contributions to the literature.

RESULTS

The incidence of idiopathic intracranial hypertension is increasing along with the obesity epidemic. Undiagnosed patients may present to otolaryngologists with pulsatile tinnitus, dizziness, sleep apnea, and spontaneous cerebrospinal fluid leaks. Although diagnosis is predicated upon imaging findings and lumbar puncture, radiographic signs including empty sella, optic nerve dilation, and globe flattening may suggest the diagnosis. The most effective intervention is weight loss combined with acetazolamide. Surgery is reserved for severe or refractory symptoms and can be highly morbid. Otolaryngologists are increasingly responsible for managing a number of secondary disorders including cerebrospinal fluid rhinorrhea and otorrhea. Failure to manage intracranial hypertension may lead to adverse surgical outcomes.

CONCLUSIONS

The knowledge base for idiopathic intracranial hypertension has greatly expanded over the past 25 years. This disease is associated with a number of conditions directly relevant to otolaryngologists. A keen understanding of this disorder and its management may optimize outcomes in a growing number of patients. Laryngoscope, 128:248-256, 2018.

Analysis of Audiometric Outcomes following Combined Middle Cranial Fossa/Transmastoid Approaches for Spontaneous Cerebrospinal Fluid Otorrhea

Outcome Objectives

To (1) explore audiometric outcomes following use of a combined transmastoid/middle cranial fossa (TM-MCF) approach in the treatment of spontaneous cerebrospinal fluid (CSF) otorrhea and (2) determine the influence of dehiscence location and reconstructive methodology on audiometric outcomes.

Study Design

Case series with chart review.

Setting

Tertiary care center.

Subjects and Methods

Adults with spontaneous CSF otorrhea were reviewed from 2007 to 2016 if they underwent combined TM-MCF. Definitive audiometric evaluations were performed at least 3 months postoperatively. The primary outcomes measures were pre- to postoperative changes in pure-tone average (PTA) and air-bone gap (ABG). Two subset analyses were performed for audiometric outcomes comparisons: first, patients with skull base dehiscences anterior to the ossicular chain were compared with those with posterior dehiscences. Second, patients undergoing skull base resurfacing plus abdominal fat graft mastoid obliteration (AFGMO) were compared with those undergoing resurfacing alone.

Results

A total of 28 patients and 31 ears were reviewed. There was 1 recurrent leak (3.5%). The cohort demonstrated significant improvement in mean postoperative ABG ( P = .008) but not PTA. On subset analysis, ears with posterior dehiscences demonstrated significant improvements in PTA ( P = .03) and ABG ( P = .05), while ears with anterior dehiscences did not. In addition, ears undergoing resurfacing plus AFGMO achieved significant improvements on all parameters ( P = .01). Only 3 of 15 ears undergoing resurfacing plus AFGMO experienced worsened postoperative hearing.

Conclusion

Use of the combined TM-MCF approach for treating spontaneous CSF otorrhea achieved good audiometric outcomes. Patients with skull base dehiscences posterior to the ossicles and those undergoing skull base resurfacing plus AFGMO achieved the most favorable results.

Middle Ear Obliteration with Blind-Sac Closure of the External Auditory Canal for Spontaneous CSF Otorrhea

Outcome Objectives To (1) identify unique features of patients who underwent middle ear/mastoid obliteration with blind-sac closure of the external auditory canal for spontaneous cerebrospinal fluid (CSF) otorrhea and (2) explore outcomes. Study Design Case series with chart review. Setting Tertiary care center. Subjects and Methods Adults treated for spontaneous cerebrospinal fluid otorrhea from 2007 through 2015 were reviewed and stratified into 2 groups based on the surgery performed: (1) 11 patients underwent middle ear/mastoid obliteration with blind-sac closure of the external auditory canal and (2) 26 patients underwent other procedures. Demographics, body mass index, revised cardiac risk index, Duke Activity Status Index scores, and anticoagulation use were documented. Audiologic data were gathered from pre- and postoperative visits. The primary outcome measure was leak recurrence. Complications were tabulated. Results Poor preoperative hearing was a relative indication for obliteration. Obliteration patients had higher body mass index (43.2 vs 34.9 kg/m2; P < .05), incidence of super-morbid obesity (45% vs 7.6%; P = .015), anticoagulation usage (36% vs 0%; P = .004), cardiac risk scores (1.2 vs 0.1 dB; P < .0004), and Duke Activity Status Index scores. There was 1 leak recurrence (9%). Major and minor complication rates were 9% and 36%, respectively. Mean follow-up was 30.8 ± 8.6 months. Conclusion Middle ear and mastoid obliteration with blind-sac closure of the external auditory canal is effective for treating spontaneous CSF otorrhea. The small cohort reviewed did not experience any major perioperative morbidity. The technique may be best suited for patients with poor hearing, the infirm, and those in whom craniotomy is contraindicated.

Lateral Skull Base Attenuation in Superior Semicircular Canal Dehiscence and Spontaneous Cerebrospinal Fluid Otorrhea

Objectives

(1) To quantitatively assess the lateral skull base thickness in patients with superior semicircular canal dehiscense (SSCD) using a standardized and validated radiographic measure and to compare it with that of a population with spontaneous cerebrospinal fluid otorrhea (CSFO). (2) To analyze demographic and clinical factors associated with skull base thickness in the SSCD group.

Study Design

Case series with chart review.

Setting

Tertiary neurotologic referral center.

Subjects and Methods

Based on computed tomography imaging of the tegmen, mean skull base thickness was calculated for 16 patients with radiographic and clinical SSCD. Similar measures were performed in 4 comparison groups consisting of adults with spontaneous CSFO (n = 33), as well as 3 control groups recruited from our adult cochlear implant database: 30 obese controls (body mass index [BMI] >30 kg/m2), 11 overweight controls (BMI, 25-30 kg/m2), and 20 normal weight controls (BMI <25 kg/m2).

Results

The SSCD group had a significantly lower mean BMI (28.6 kg/m2) than the spontaneous CSFO group (37.7 kg/m2; P = .0007). The mean skull base thickness of SSCD patients was 17% thinner than that of the CSFO group, 31% thinner vs obese controls, 49% thinner vs overweight controls, and 45% thinner vs normal weight controls. These differences were all statistically significant ( P < .05).

Conclusion

Patients with SSCD have a marked thinning of the lateral skull base, more so than patients with spontaneous CSF otorrhea and control groups with different BMIs. Skull base attenuation in SSCD patients did not correlate with BMI.

Association between Lateral Skull Base Thickness and Surgical Outcomes in Spontaneous CSF Otorrhea

OBJECTIVES

(1) Correlate skull base thickness with perioperative outcomes for spontaneous cerebrospinal fluid (CSF) otorrhea. (2) Augment perioperative counseling of patients with abnormally thin skull bases.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary center. Patients with spontaneous CSF otorrhea have thin skull bases. This is associated with obesity and/or idiopathic intracranial hypertension. The influence of skull base thinning on perioperative outcomes is unknown.

SUBJECTS AND METHODS

A retrospective review was conducted from 2004 to 2014. Forty-eight cases of spontaneous CSF otorrhea met the inclusion criteria of primary surgery by the senior authors: preoperative dedicated temporal bone computed tomography, absence of other leak etiologies, and follow-up >6 months. Patients were stratified into thin (<0.9 mm) and thick (>0.9 mm) groups based on computed tomography measures of their tegmen. Primary outcomes measures were as follows: postoperative meningitis, recurrent leak, second site leak (contralateral ear/anterior fossa), and permanent shunt placement. Hearing outcomes were not assessed in this study.

RESULTS

Thirty and 15 patients composed the thin and thick groups, respectively. Both the incidence (P < .0001) and the rate (P = .005) of adverse outcomes were significantly higher in the thin group. Only 2 patients in the thick group experienced an adverse outcome. Eleven patients underwent multiple procedures for spontaneous leaks. The recurrence rate was 14.5%. All but 1 recurrence occurred in the thin group.

CONCLUSIONS

An abnormally thin tegmen was significantly associated with adverse perioperative outcomes in cases of spontaneous CSF otorrhea. A thick skull base and the presence of an encephalocele may be protective against recurrence. The effect of untreated intracranial hypertension on the results is unknown.

Lateral Skull Base Attenuation in Patients with Anterior Cranial Fossa Spontaneous Cerebrospinal Fluid Leaks

Objective

(1) Determine if patients with anterior fossa spontaneous cerebrospinal fluid (SCSF) leaks demonstrate lateral skull base bone attenuation. (2) Examine the relation between body mass index (BMI; kg/m2) and skull base thickness.

Study Design

Retrospective cohort study.

Setting

Tertiary care hospital.

Subjects and Methods

Retrospective review from 2004 to 2013 identified 96 patients with anterior cranial fossa SCSF leaks. A control group was identified from a consecutive series of clinic patients. Controls had no history of chronic sinonasal or temporal bone pathology and were divided according to BMI into nonobese (<30 kg/m2) and obese (≥30 kg/m2) groups. Composite skull base thickness was calculated for lateral and anterior subsites through predefined points according to previously published protocols.

Results

Thirty-two patients were included in each group. Composite lateral skull base thickness was less in patients with SCSF leaks(0.7 ± 0.1 mm) when compared with nonobese controls (0.8 ± 0.1 mm, P = .004); no differences were apparent when SCSF leaks were compared with obese controls (0.7 ± 0.1 mm, P = .99). A direct relation was observed between anterior skull base and lateral skull base thickness ( r = 0.48, P < .0001). An inverse correlation was noted between BMI and lateral skull base ( r =−0.40, P < .0001).

Conclusions

Patients with anterior fossa SCSF leaks demonstrate attenuation of the lateral skull base. A significant correlation between anterior skull base thickness and lateral skull base thickness was observed. BMI was inversely related to lateral skull base thickness. Taken together, SCSF leaks are associated with obesity, which appears to be partly responsible for diffuse skull base erosion observed in patients with this condition.

The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research involving the cochlea and its associated neural pathways entails exposure of model cochleae to a variety of ototoxic agents. This allows investigators to study the effects of targeted damage to cochlear structures, and in some cases, the self-repair or regeneration of those structures. Various techniques exist for delivery of ototoxic agents to the cochlea. When selecting a particular technique, investigators must consider a number of factors, including the induction of inadvertent systemic toxicity, the amount of cochlear damage produced by the surgical procedure itself, the type of lesion desired, animal survivability, and reproducibility/reliability of results. Currently established techniques include parenteral injection, intra-peritoneal injection, trans-tympanic injection, endolymphatic sac injection, and cochleostomy with perilymphatic perfusion. Each of these methods has been successfully utilized and is well described in the literature; yet, each has various shortcomings. Here, we present a technique for topical application of ototoxic agents directly to the round window niche. This technique is non-invasive to inner ear structures, produces rapid onset of reliably targeted lesions, avoids systemic toxicity, and allows for an intra-animal control (the contra-lateral ear). Results stemming from this approach have helped deeper understanding of auditory pathophysiology, cochlear cell degeneration, and regenerative capacity in response to an acute injury. Future investigations may use this method to conduct interventional studies involving gene therapy and stem cell transplantation to combat hearing loss.

Novel radiographic measurement algorithm demonstrating a link between obesity and lateral skull base attenuation

OBJECTIVES

(1) To describe a validated algorithm for measuring tegmen thickness on computed tomography scans. (2) To compare the tegmen thickness in 3 groups: patients with spontaneous cerebrospinal fluid (CSF) leaks, obese controls, and nonobese controls.

STUDY DESIGN

Retrospective review.

SETTING

Patients with spontaneous CSF otorrhea often have highly attenuated tegmen plates. This is associated with obesity and/or idiopathic intracranial hypertension (IIH). No evidence exists, however, that objectively links obesity and/or IIH with skull base attenuation.

SUBJECTS AND METHODS

This was a retrospective review from 2004 to the present. Patients with spontaneous CSF otorrhea and matched obese (body mass index [BMI] >30 kg/m(2)) and nonobese (BMI <30 kg/m(2)) controls were selected. Tegmen thickness was measured radiographically. Interrater validity was assessed.

RESULTS

Ninety-eight patients were measured: 37 in the CSF group (BMI, 36.6 kg/m(2)), 30 in the obese group (BMI, 34.6 kg/m(2)), and 31 in the nonobese group (BMI, 24.2 kg/m(2)). The CSF group had a significantly thinner tegmen compared to both the obese control (P < .01) and nonobese control (P = .0004) groups. Obese controls had a thinner tegmen than nonobese controls (P < .00001). A significant inverse correlation was detected between skull base thickness and BMI. Signs/symptoms of IIH were most commonly found in the CSF group. Good to very good strength of agreement was detected for measures between raters.

CONCLUSION

This is the first study to (1) quantify lateral skull base thickness and (2) significantly correlate obesity with lateral skull base attenuation. Patients who are obese with spontaneous CSF leaks have greater attenuation of their skull base than matched obese controls. This finding supports theories that an additional process, possibly congenital, has a pathoetiological role in skull base dehiscence.

Novel Radiographic Measurement Algorithm Demonstrating a Link between Obesity and Lateral Skull Base Attenuation

Objectives:

(1) Describe a validated measurement instrument to quantify tegmen thickness on computed tomography (CT) images. (2) Compare tegmen thickness in 3 groups: patients with spontaneous cerebrospinal fluid (CSF) leaks, obese controls, and nonobese controls.

Methods:

Retrospective review from 2005 to present. Patients with a diagnosis of spontaneous CSF otorrhea and dedicated temporal bone CT scans were included. Matched obese (body mass index [BMI] >30) and nonobese (BMI <30) controls were selected from a pool of cochlear implant candidates. The tegmen was measured radiographically in all patients at pre-defined points. Independent, blinded measurements were made by 3 of the authors and compared for interrater validity.

Results:

Ninety-nine patients were measured: 39 in the CSF group (BMI 35.9), 29 in the obese group (BMI 34.6), and 31 in the nonobese group (BMI 24.2). The CSF group had a significantly thinner aggregate tegmen thickness (0.82 mm ± 0.19) compared with both obese controls (0.99 mm ± 0.18, P = .007) and nonobese controls (1.26 mm ± 0.2, P < .001). Obese controls were thinner than non obese controls ( P < .001). Signs/symptoms of benign intracranial hypertension (BIH) were most commonly found in the CSF group. No other factors significantly affected thickness. Good to excellent correlation of measurements was found between all 3 raters.

Conclusions:

This is the first study to (1) quantify lateral skull base thickness and (2) significantly correlate obesity with lateral skull base attenuation. Obese spontaneous CSF leak patients may have even greater attenuation of their skull base than matched obese controls. This finding may further support theories that an additional process, such as BIH, may play an important pathophysiologic role in skull base thinning.

Exclusion of deep vein thrombosis using the Wells rule in clinically important subgroups: individual patient data meta-analysis

OBJECTIVE

To assess the accuracy of the Wells rule for excluding deep vein thrombosis and whether this accuracy applies to different subgroups of patients.

DESIGN

Meta-analysis of individual patient data.

DATA SOURCES

Authors of 13 studies (n = 10,002) provided their datasets, and these individual patient data were merged into one dataset.

ELIGIBILITY CRITERIA

Studies were eligible if they enrolled consecutive outpatients with suspected deep vein thrombosis, scored all variables of the Wells rule, and performed an appropriate reference standard.

MAIN OUTCOME MEASURES

Multilevel logistic regression models, including an interaction term for each subgroup, were used to estimate differences in predicted probabilities of deep vein thrombosis by the Wells rule. In addition, D-dimer testing was added to assess differences in the ability to exclude deep vein thrombosis using an unlikely score on the Wells rule combined with a negative D-dimer test result.

RESULTS

Overall, increasing scores on the Wells rule were associated with an increasing probability of having deep vein thrombosis. Estimated probabilities were almost twofold higher in patients with cancer, in patients with suspected recurrent events, and (to a lesser extent) in males. An unlikely score on the Wells rule (≤ 1) combined with a negative D-dimer test result was associated with an extremely low probability of deep vein thrombosis (1.2%, 95% confidence interval 0.7% to 1.8%). This combination occurred in 29% (95% confidence interval 20% to 40%) of patients. These findings were consistent in subgroups defined by type of D-dimer assay (quantitative or qualitative), sex, and care setting (primary or hospital care). For patients with cancer, the combination of an unlikely score on the Wells rule and a negative D-dimer test result occurred in only 9% of patients and was associated with a 2.2% probability of deep vein thrombosis being present. In patients with suspected recurrent events, only the modified Wells rule (adding one point for the previous event) is safe.

CONCLUSION

Combined with a negative D-dimer test result (both quantitative and qualitative), deep vein thrombosis can be excluded in patients with an unlikely score on the Wells rule. This finding is true for both sexes, as well as for patients presenting in primary and hospital care. In patients with cancer, the combination is neither safe nor efficient. For patients with suspected recurrent disease, one extra point should be added to the rule to enable a safe exclusion.

Heptanol application to the mouse round window: a model for studying cochlear lateral wall regeneration

OBJECTIVE

Identify cells supporting cochlear lateral wall regeneration.

STUDY DESIGN

Prospective controlled trial.

SETTING

Laboratory. Human presbyacusis occurs, in part, secondary to age-related degeneration of cochlear lateral wall structures such as the stria vascularis and spiral ligament fibrocytes. This degeneration is likely linked to the diminished regenerative capacity of lateral wall cells with age. While lateral wall regeneration is known to occur after an acute insult, this process remains poorly understood and the cells capable of self-replication unidentified. We hypothesized that spiral ligament fibrocytes constitute these proliferative cells.

SUBJECTS AND METHODS

To test the hypothesis, an acute ototoxic insult was created in 65 normal-hearing, young adult mice via cochlear exposure to heptanol. Sacrifice occurred at 1 to 60 days posttreatment. Auditory brainstem responses, 5-ethynyl-2'-deoxyuridine assay, and immunostaining were used to assess regeneration.

RESULTS

Posttreatment hearing thresholds were elevated in nearly all treated mice. Selective fibrocyte apoptosis and strial injury were observed at the time of peak hearing loss around 1 to 7 days posttreatment. Cellular proliferation was detected in the region of type II fibrocytes during this time. Hearing thresholds plateaued at 7 days posttreatment followed by a significant recovery of both hearing and morphologic appearance. Permanent outer hair cell degeneration was observed.

CONCLUSIONS

Heptanol application to the round window of young adult mice is a rapid, selective, and reliable technique for investigating proliferation in the cochlear lateral wall. The data indirectly showed that spiral ligament fibrocytes may be the proliferative cells of the cochlear lateral wall. Further studies of this process are needed.

Heptanol Application to the Mouse Round Window: A Novel Model for Studying Cochlear Regenerative Potential

Objectives:

1) Introduce a novel model for studying cochlear lateral wall regeneration. 2) Describe implications of this study on research and treatment of human presbycusis. Background: Human presbycusis likely occurs secondary to senile degeneration of the stria vascularis (SV) and spiral ligament fibrocytes (SLFs). SLFs have a limited regenerative capacity. Augmenting this process may play a role in hearing preservation, recovery, or both. Few models currently exist, however, that can selectively and temporarily damage the cochlear lateral wall to study SLF regeneration.

Methods:

Heptanol, a gap junction uncoupler, was surgically applied to the round window of 25 normal hearing mice, with sacrifice at points 12 hours - 14 days post-treatment. Auditory brainstem response testing, electron microscopy, and immunostaining techniques were used to assess treatment response.

Results:

Click tone thresholds were significantly elevated (mean +40.5 dB sound pressure level) in all treated mice. Hearing loss plateaued on days 1-7, followed by near complete recovery thereafter. Ultrastructural analysis revealed selective SV injury and SLF apoptosis at the apical, middle, and basal turns. A marked reduction in ion channel immunostaining intensity occurred throughout the lateral wall but resolved by 2 weeks. 3-4 days, SLFs stained positive for EdU, a labeled thymidine analog and marker of cellular proliferation.

Conclusions:

This is one of the first models described to reliably and selectively induce lateral wall toxicity followed by full hearing recovery and SLF regeneration. Future study of the molecular and genetic expression profiles governing this process will be greatly facilitated by this technique.

Age-related changes of myelin basic protein in mouse and human auditory nerve

Age-related hearing loss (presbyacusis) is the most common type of hearing impairment. One of the most consistent pathological changes seen in presbyacusis is the loss of spiral ganglion neurons (SGNs). Defining the cellular and molecular basis of SGN degeneration in the human inner ear is critical to gaining a better understanding of the pathophysiology of presbyacusis. However, information on age-related cellular and molecular alterations in the human spiral ganglion remains scant, owing to the very limited availably of human specimens suitable for high resolution morphological and molecular analysis. This study aimed at defining age-related alterations in the auditory nerve in human temporal bones and determining if immunostaining for myelin basic protein (MBP) can be used as an alternative approach to electron microscopy for evaluating myelin degeneration. For comparative purposes, we evaluated ultrastructural alternations and changes in MBP immunostaining in aging CBA/CaJ mice. We then examined 13 temporal bones from 10 human donors, including 4 adults aged 38-46 years (middle-aged group) and 6 adults aged 63-91 years (older group). Similar to the mouse, intense immunostaining of MBP was present throughout the auditory nerve of the middle-aged human donors. Significant declines in MBP immunoreactivity and losses of MBP(+) auditory nerve fibers were observed in the spiral ganglia of both the older human and aged mouse ears. This study demonstrates that immunostaining for MBP in combination with confocal microscopy provides a sensitive, reliable, and efficient method for assessing alterations of myelin sheaths in the auditory nerve. The results also suggest that myelin degeneration may play a critical role in the SGN loss and the subsequent decline of the auditory nerve function in presbyacusis.

Measurement of Acetylcholine in Rat Brain Microdialysates by LC - Isotope Dilution Tandem MS

An LC-MS/MS method was developed for measuring acetylcholine (ACh) in an aqueous medium using reversed-phase ion-pair chromatography, electrospray ionization on a quadrupole ion trap instrument and a tetradeuterated analogue (ACh-1,1,2,2-d(4)) as an internal standard. A rapid separation was achieved on a 5-cm long octadecylsilica column (2.1 mm i.d.) by employing heptafluorobutyric acid (0.1% v/v) as an ion-pairing agent and requiring 10% v/v acetonitrile in 20 mM ammonium formate buffer under isocratic elution at 200 μl/min flow rate. The instrument's response was calibrated with samples containing known mole ratios of ACh and ACh-1,1,2,2-d(4) in an artificial cerebrospinal fluid, which afforded the conclusion that analyte concentrations could be determined by multiplying the measured analyte to internal standard ion-current ratio with the known molar concentration of the ACh-1,1,2,2-d(4) added. The rapid and simple assay was tested by measuring the basal neurotransmitter concentration in rat brain microdialysates without the use of a cholinesterase inhibitor upon sample collection.

The flagellar filament of Rhodobacter sphaeroides: pH-induced polymorphic transitions and analysis of the fliC gene

Flagellar motility in Rhodobacter sphaeroides is notably different from that in other bacteria. R. sphaeroides moves in a series of runs and stops produced by the intermittent rotation of the flagellar motor. R. sphaeroides has a single, plain filament whose conformation changes according to flagellar motor activity. Conformations adopted during swimming include coiled, helical, and apparently straight forms. This range of morphological transitions is larger than that in other bacteria, where filaments alternate between left- and right-handed helical forms. The polymorphic ability of isolated R. sphaeroides filaments was tested in vitro by varying pH and ionic strength. The isolated filaments could form open-coiled, straight, normal, or curly conformations. The range of transitions made by the R. sphaeroides filament differs from that reported for Salmonella enterica serovar Typhimurium. The sequence of the R. sphaeroides fliC gene, which encodes the flagellin protein, was determined. The gene appears to be controlled by a sigma(28)-dependent promoter. It encodes a predicted peptide of 493 amino acids. Serovar Typhimurium mutants with altered polymorphic ability usually have amino acid changes at the terminal portions of flagellin or a deletion in the central region. There are no obvious major differences in the central regions to explain the difference in polymorphic ability. In serovar Typhimurium filaments, the termini of flagellin monomers have a coiled-coil conformation. The termini of R. sphaeroides flagellin are predicted to have a lower probability of coiled coils than are those of serovar Typhimurium flagellin. This may be one reason for the differences in polymorphic ability between the two filaments.

Medical savings accounts (MSAs)--big benefits for small business

The Health Insurance Portability and Accountability Act, passed by Congress last year, implemented a four-year pilot project that allows employees of small businesses to set up tax-free interest-bearing medical savings accounts. These accounts offer advantages for both employees and employers

Estimating neonatal mortality risk: an analysis of clinicians' judgments

BACKGROUND

Clinicians' estimates of mortality risk in the neonatal intensive care unit (NICU) have implications for patient triage, transfer, initiation and termination of life support, and allocation of medical resources. The accuracy of these judgments has not been studied, nor the differences between nurses and attending physicians.

OBJECTIVES

1) evaluate the accuracy of subjective judgments of NICU unit mortality risk, 2) identify the key components of clinician judgments, 3) compare accuracy between attending physicians and nurses, and 4) examine the utility of combining an objectively computed risk and clinician judgments to improve predictions.

METHODS

We obtained estimates of mortality risk on 544 admissions to two NICUs on the day of admission from the attending physician and primary nurse. These were compared with an objective computed mortality risk based on birth weight and the Score for Neonatal Acute Physiology (SNAP) using a linear judgment analysis model, as well as with actual outcomes.

RESULTS

Physicians and nurses had good discriminating power with actual mortality rates ranging from 0% among low risk patients to 67% among those with the highest mortality estimates. Physicians had a tendency to overestimate mortality risk. Clinicians base their estimates on the same factors and similar judgment weights as the empiric mortality risk model (22% birth weight, 62% illness severity (SNAP), 13% low Apgar, and 3% for intrauterine growth restriction). Clinicians place additional emphasis on therapeutic as well as physiologic factors. When the computed risk and physician judgment were combined, both made significant contributions in a logistic mortality risk model.

CONCLUSIONS

Clinician judgments of mortality risk are fairly accurate and similar to an objective illness severity index. This simple method provides insight into clinical decision making and has important applications in improving direct patient care, appropriate allocation of medical resources, and medical training.

Rectal spirochaetosis in homosexual men: the association with sexual practices, HIV infection and enteric flora

OBJECTIVE

To determine the prevalence of rectal spirochaetosis in homosexual men attending a sexually transmissible diseases clinic and investigate the association between their presence and sexual practices, HIV infection and enteric flora.

DESIGN

The study included 144 male homosexual subjects who each completed a questionnaire, underwent physical examination, proctoscopy and investigations for STD and HIV screening, rectal biopsies and collection of faecal samples.

SETTING

The Sexual Health Centre, Sydney Hospital, Sydney, Australia.

RESULTS

Spirochaetes were detected in 39% of the rectal biopsies, using histological criteria. Logistic regression analysis showed that rectal spirochaetosis was significantly associated with: oral-anal contact. (P < 0.05, OR 3.45, 95% CI 1.48-8.05); detection of 3-5 different non-pathogenic protozoa in faeces (P < 0.01, OR 11.68, 95% C.I. 2.33-58) and a positive HIV antibody test (P < 0.01) OR 4.48, 95% C.I. 1.28-15.72).

CONCLUSIONS

These findings indicate that rectal spirochaetosis is relatively common in homosexual men. The association with non-pathogenic protozoa is most likely attributable to the common mode of transmission viz oral-anal contact. However it is difficult to determine whether the association with HIV infection is cause or effect because of the limitations in the study design. Further information is required to determine the clinical significance of infection with these organisms.

Subclinical ischaemic episodes during the steady state of sickle cell anaemia

AIMS

To determine the clinical, haematological, biochemical and rheological changes that occur in the asymptomatic steady state of sickle cell anaemia.

METHODS

Patient self-assessment visual analogue scores (for wellbeing and tiredness), the blood concentration of acute phase proteins (C-reactive protein, orosomucoid, and fibrinogen), and blood rheology (percentage of dense cells and the number of sickled cells that occluded pores 5 microns in diameter) were studied longitudinally on 10 occasions in each of 20 outpatients with sickle cell anaemia.

RESULTS

Patients in the steady state showed fluctuation in visual analogue scores, in concentration of acute phase proteins, and in rheological parameters consistent with minor episodes of tissue injury. Significantly more variation in acute phase proteins occurred in the steady state of 14 of the 20 patients who developed one or more vaso-occlusive crises during the 16 month study period. Rheological fluctuation in the steady state simulated rheological change during crisis, namely a transient rise and then fall in the number of dense and poorly filterable cells.

CONCLUSIONS

The term "steady state" is a misnomer, being characterised by biochemical and rheological fluctuation consistent with minor episodes of microvascular occlusion that are insufficient to cause the overt tissue infarction of painful crisis.

Rheological changes in the prodromal and established phases of sickle cell vaso-occlusive crisis

A rheological study has been made in 20 patients with sickle cell anaemia in the steady state and in the prodromal and established phases of 12 vaso-occlusive crises. Rheology of sickle cells was studied by discontinuous density gradient fractionation and by filtration through pores of 5 microns diameter. The prodromal phase of crisis (day 1), when compared with mean steady state values, was associated with the development of a sub-population of poorly deformable dense cells. This sub-population appeared 1 or more days before the acute-phase rise in C-reactive protein, orosomucoid, fibrinogen, plasma viscosity and leucocytes, and before the rise in serum lactate dehydrogenase. As crisis evolved, the sub-population decreased to steady-state values, or below, by days 6-7. Identification of the prodromal phase of sickle cell crisis has allowed the detection of rheological changes of potential aetiological significance.

Concurrent zidovudine-induced myopathy and hepatoxicity in patients treated for human immunodeficiency virus (HIV) infection

Myopathy and hepatic toxicity are important complications of zidovudine (3'-azido-3'-deoxythymidine therapy) in patients infected with the human immunodeficiency virus (HIV) both may also occur in HIV infection in the absence of zidovudine therapy. We report 2 cases of myopathy caused by zidovudine, occurring within 16 wks of initiation of therapy, and a case of concurrent hepatic and muscle toxicity. In one case, electron microscopy demonstrated characteristic enlarged mitochondria with paracrystalline inclusions. This technique can distinguish the myopathies caused by either HIV or zidovudine. Both zidovudine-induced myopathy and hepatoxicity require discontinuation of the drug if severe.

The effects of anthranilic acid on gene expression

1. A Drosophila pseudoobscura amylase gene cloned in Escherichia coli is expressed at high levels. The expression of this gene is repressed when glucose (0.5% final concentration) is added to a starch minimal medium culture of E. coli cells containing the amylase plasmid. 2. Addition of anthranilic acid (5 and 7 mM final exogenous concentration) to catabolite repressed cells mimics the action of adenosine 3'5' cyclic monophosphate (cAMP) by depressing the expression of the amylase. 3. The results suggest that anthranilic acid acts either indirectly, possibly through the glucose transport system, or directly, by way of an intercalative model of initiation, to alter the levels of transcription.

Effect of polymerization tendency on haematological, rheological and clinical parameters in sickle cell anaemia

The polymerization tendency of sickle haemoglobin was estimated as a function of oxygen saturation in 30 patients with homozygous sickle cell anaemia. The deformability of their erythrocytes was also measured, by initial-flow-rate filtration at 37 degrees C through pores of 5 microns diameter, and clinical severity was assessed using a visual analogue scale. By means of partial correlation analysis, it was found that correlations between haematological, rheological, and clinical parameters in sickle cell anaemia could be explained on the basis of an association of each variable with polymerization tendency. Patients with the greatest tendency to form polymer had the least deformable erythrocytes and perceived their disease to be more severe as judged by the visual analogue scale. Polymer formation also appeared to be a determinant of the number of dense cells which, in turn, determine haemolytic rate and erythrocyte deformability.

An amylase gene from Drosophila pseudoobscura is expressed in Escherichia coli. Functional selection and biochemical comparisons of the fly- and clone-produced amylases

An amylase gene from Drosophila pseudoobscura was isolated from a genomic library constructed in pBR322 and cloned in Escherichia coli by selecting for the ability of its product to hydrolyze starch, a carbon source not normally utilized by E. coli. Hybridization of pAMY17F to D. pseudoobscura polytene chromosomes shows a positive signal at the amylase pseudogene locus (bank 78, chromosome 3). The chimeric plasmid pAMY17F, has been altered in such a way as to increase amylase expression. Southern and Northern hybridizations to the cloned amylase DNA indicate that the source of the gene is from D. pseudoobscura. Biochemical properties such as pH optima, substrate specificities, electrophoretic analyses, inhibitor sensitivities, heat stabilities, temperature responsiveness and molecular weights indicate that the amylases produced by the fly and bacterial clone are similar and have similar properties. It appears that E. coli/pAMY17F is producing an amylase like that found in D. pseudoobscura.

Primary cerebral neuroblastomas. A clinicopathological study of one adolescent and five adult patients

Neuronal differentiation was demonstrated by light microscopy, immunohistochemistry and electron microscopy in the cerebral neoplasms of one adolescent and five adult patients. The tumours exhibited a wide spectrum of cellular differentiation from low to high grade malignancy which seems to correlate well with their biological behaviour. The natural history of these 6 cerebral neuroblastomas is rather long compared to that of other malignant primary cerebral neoplasms of adulthood; however, 2 patients died, one survived about 5 yr after initial symptoms whilst an untreated patient survived more than 12 yr. It is suggested that morphological grading along the lines of Kernohan's system may be useful in determining the prognosis and postoperative management of patients with cerebral neuroblastomas.

Atypical polypoid adenomyoma: a case report with ultrastructural examination

A case of atypical polypoid adenomyoma occurring in a 40 yr-old female is reported. The lesion was composed of irregular glands lined by atypical epithelium lying in a spindle cell stroma containing smooth muscle cells. The mitotic count of the stroma was less than 1 per 10 high power fields. Squamous metaplasia was present in the glandular elements. Ultrastructural examination of the stroma confirmed the presence of smooth muscle cells. The lesion is compared with similar cases previously reported. The differential diagnosis is considered, including endometrial adenocarcinoma, adenomyosis, endometrial polyps and mixed Mullerian tumours. Atypical polypoid adenomyoma is a benign lesion, and conservative management is recommended.

Round-headed spermatozoa: a case report

A case is presented of a patient in whom over 90% of spermatozoa had distinctive round heads as seen by light microscopy. Other features of his semen were only slightly abnormal. Electron microscopy revealed spermatozoa with no acrosome confirming the sterility of the patient. With such men other means of achieving a family must be considered.

Neuronal ceroid lipofuscinosis in the amaurotic retardate: electron microscopic confirmation

The clinical features of two cases of blindness with pigmentary retinopathy in young retardates are presented. The diagnosis of neuronal ceroid lipofuscinosis (Batten's Disease) was suspected. This was confirmed in both cases by electron microscopic examination of blood and skin with demonstration of fingerprint and curvilinear inclusions. These inclusions are present in cells other than neurons; circulating lymphocytes, smooth muscle cells and eccrine sweat glands suggesting a more widespread pathological process. Less invasive procedures namely venepuncture and skin biopsy may be preferred to brain and rectal biopsy in the absence of a practical biochemical analysis at the present time.

Crigler-Najjar Type 1 syndrome: absence of hepatic bilirubin UDP-glucuronyl transferase activity and therapeutic responses to light

A 16-year-old boy with severe congenital unconjugated hyperbilirubinaemia is described in whom mental retardation occurred as an isolated neurological deficit. The diagnosis of Crigler-Najjar type 1 syndrome was supported by an extreme and persistent elevation of serum unconjugated bilirubin (650 mumol/l), failure of administered phenobarbitone to lower serum bilirubin concentration and family history of a similarly affected sibling. Hepatic bilirubin UDP-glucuronyl transferase activity determined in vitro by a sensitive new enzyme assay was found to be absent using bilirubin or bilirubin monoglucuronide as substrate. Phototherapy for 12 hours each night produced a partial but highly significant reduction in serum bilirubin concentration, which was not influenced further by the administration of cholestyramine.

Necrotizing and giant cell granulomatous phlebitis of caecum and ascending colon

A distinctive form of necrotizing and granulomatous phlebitis of a segment of large intestine is described in a previously healthy 36-year-old woman who presented with sudden severe abdominal pain and diarrhoea. At operation the caecum and ascending colon were oedematous and inflamed and right hemicolectomy was performed. Microscopically there was striking involvement of veins in all coats of the bowel ranging from recent fibrinoid necrosis of the whole vessel wall in the case of the caecum, to more chronic giant cell granulomas in parts of the vessel wall with partial or complete occlusion of the lumen in ascending colon. Arteries and lymphatics were entirely spared of these changes. The aitiology of this condition has not been elucidated but the histological appearances and site of involvement suggest an immunological reaction to material absorbed from the bowel. No evidence of food or other allergies or of infection has been obtained. The patient remains symptom free after 18 months. This form of phlebitis does not appear to have been previously described.

The restoration of the vasculature of skin autografts in the rabbit

The restoration of the vasculature of full-thickness skin autografts was investigated on the rabbit ear, the grafted discs of skin being replaced with their original orientation, or rotated 90 or 180 degrees. Circulation in the graft was first detected 1 day after grafting, increasing on the 2nd and successive days. The larger arteries in the grafts survived and became permanently joined at the periphery of the grafts to adjacent severed arteries in the host by well-defined and often tortuous segments termed junction vessels. The pre-operative vascular pattern was re-established when grafts were replaced without rotation but comparable survival of arteries also occurred when the grafted discs of skin were rotated. In most grafts, the segment of artery became stabilized by 4-9 weeks; more than 75% of the length of the arterial segments survived in 83% of grafts, with minimal accompanying histological changes in their walls. There was some increase in number and aborization of small vessels in the established grafts, although the vascular pattern was essentially similar to that of unoperated skin. The factors possibly involved in the survival of the large arteries in the grafts include the relative rigidity of the arterial wall, the early establishment of circulation, and the favourable haemodynamic position of the grafts.