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The response of the metal-organic framework aluminum-1,4-cyclohexanedicarboxylate or Al-CAU-13 (CAU: Christian Albrecht University) to the application of thermal and mechanical stimuli was investigated using synchrotron powder X-ray diffraction (SPXRD). Variable temperature in situ SPXRD data, over the range 80-500 K, revealed a complex evolution of the structure of the water guest containing Al-CAU-13H 2 O, the dehydration process from ca. 310 to 370 K, and also the evolution of the guest free Al-CAU-13 structure between ca. 370 and 500 K. Rietveld refinement allowed this complexity to be rationalized in the different regions of heating. The Berman thermal Equation of State was determined for the two structures (Al-CAU-13H 2 O and Al-CAU-13). Diamond anvil cell studies at elevated pressure (from ambient to up to ca. 11 GPa) revealed similarities in the structural responses on application of pressure and temperature. The ability of the pressure medium to penetrate the framework was also found to be important: non-penetrating silicone oil caused pressure induced amorphization, whereas penetrating helium showed no plastic deformation of the structure. Third-order Vinet equations of state were calculated and show Al-CAU-13H 2 O is a hard compound for a metal-organic framework material. The mechanical response of Al-CAU-13, with tetramethylpyrazine guests replacing water, was also investigated. Although the connectivity of the structure is the same, all the linkers have a linear e , e -conformation and the structure adopts a more open, wine-rack-like arrangement, which demonstrates negative linear compressibility (NLC) similar to Al-MIL-53 and a significantly softer mechanical response. The origin of this variation in behavior is attributed to the different linker conformation, demonstrating the influence of the S-shaped a , a -conformation on the response of the framework to external stimuli.

The metallocene-based linker molecule 1,1'-ferrocenedicarboxylic acid (H 2 FcDC) was used to synthesize four different polymorphs of composition [In(OH)(FeC 12 H 8 O 4 )]. Using conventional solvent-based synthesis methods and varying the synthetic parameters such as metal source, reaction temperature, and solvent, two different MOFs and one 1D-coordination polymer denoted as CAU-43 ( 1 ), In-MIL-53-FcDC_a ( 2 ), and In-FcDC ( 3 ) were obtained. Furthermore, thermal treatment of CAU-43 ( 1 ) at 190 °C under vacuum yielded a new polymorph of 2 , In-MIL-53-FcDC_b ( 4 ). Both MOFs 2 and 4 crystallize in a MIL-53 type structure, but in different space groups C 2/ m for 2 and P 1̅ for 4 . The structures of the four title compounds were determined by single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), or a combination of three-dimensional electron diffraction measurements (3D ED) and PXRD. N 2 sorption experiments of 1 , 2 , and 4 showed specific surface areas of 355 m 2 g -1 , 110 m 2 g -1 , and 140 m 2 g -1 , respectively. Furthermore, the electronic properties of the title compounds were characterized via Mössbauer and EPR spectroscopy. All Mössbauer spectra showed the characteristic doublet, proving the persistence of the ferrocene moiety. In the cases of 1 , 3 , and 4 , appreciable impurities of ferrocenium ions could be detected by electron paramagnetic resonance spectroscopy. Cyclovoltammetric experiments were performed to demonstrate the accessible redox activity of the linker molecule of the title compounds. A redox process of FcDC 2- with oxidation (between 0.86 and 0.97 V) and reduction wave (between 0.69 and 0.80 V) was observed.

The application of machine learning (ML) for use in generating insights and making predictions on new records continues to expand within the medical community. Despite this progress to date, the application of time series analysis has remained underexplored due to complexity of the underlying techniques. In this study, we have deployed a novel ML, called automated time series (AutoTS) machine learning, to automate data processing and the application of a multitude of models to assess which best forecasts future values. This rapid experimentation allows for and enables the selection of the most accurate model in order to perform time series predictions. By using the nation-wide ICD-10 (International Classification of Diseases, Tenth Revision) dataset of hospitalized patients of Romania, we have generated time series datasets over the period of 2008-2018 and performed highly accurate AutoTS predictions for the ten deadliest diseases. Forecast results for the years 2019 and 2020 were generated on a NUTS 2 (Nomenclature of Territorial Units for Statistics) regional level. This is the first study to our knowledge to perform time series forecasting of multiple diseases at a regional level using automated time series machine learning on a national ICD-10 dataset. The deployment of AutoTS technology can help decision makers in implementing targeted national health policies more efficiently.

A new scandium metal-organic framework (Sc-MOF) with the composition of [Sc(OH)(OBA)], denoted as Sc-CAU-21, was prepared under solvothermal reaction conditions using 4,4'-oxidibenzoic acid (H 2 OBA) as the ligand. Single-crystal structure determination revealed the presence of the new inorganic building unit (IBU) {Sc 8 (μ-OH) 8 (O 2 C) 16 }. It is composed of cis-connected ScO 6 polyhedra forming an eight-membered ring through bridging μ-OH groups. The connection of the IBUs leads to a 3D framework, containing 1D pores with a diameter between 4.2 and 5.6 Å. Pore access is limited by the size of the IBU, and in contrast to the isoreticular aluminum compound Al-CAU-21 [Al(OH)(OBA)], which is nonporous toward nitrogen at 77 K, Sc-CAU-21 exhibits a specific surface area of 610 m 2 g -1 . The title compound is thermally stable in air up to 350 °C and can be employed as a host for photoluminescent ions. Sc-CAU-21 exhibits a ligand-based blue emission, and (co)substituting Sc 3+ ions with Ln 3+ ions (Eu 3+ , Tb 3+ , and Dy 3+ ) allows the tuning of the emitting color of the phosphor from red to green. Single-phase white-light emission with CIE color coordinates close to the ideal for white-light emission was also achieved. The luminescence property was utilized in combination with powder X-ray diffraction to study in situ the crystallization process of Sc-CAU-21:Tb and Sc-CAU-21:Eu. Both studies indicate a two-step crystallization process, with a crystalline intermediate, prior to the formation of Sc-CAU-21:Ln.

A metallocene based linker 1,1'-ferrocenedicarboxylic acid (H2FcDC) was used to synthesise the first permanently porous ferrocenedicarboxylate, exhibiting a MIL-53 architecture. This compound Al-MIL-53-FcDC [Al(OH)(FcDC)] is obtained in glass vials under mild synthesis conditions at ≤100 °C and after a short reaction time of 90 min. The crystal structure was determined from powder X-ray diffraction data and the compound shows porosity towards N2 and H2O, exhibiting a BET surface area of 340 m2 g-1. Furthermore, the MOF was characterised via EPR and Mössbauer spectroscopy. The Mössbauer spectrum of Al-MIL-53-FcDC shows a characteristic doublet with an isomeric shift of 0.34 mm s-1 and a quadrupole splitting of 2.39 mm s-1, proving the persistence of the ferrocene moiety. A negligibly small amount of impurities of ferrocenium ions could be detected by EPR spectroscopy as a complementary technique. Cyclic voltammetric experiments demonstrated the accessible redox activity of the linker molecule FcDC2- in Al-MIL-53-FcDC. A reversible oxidation and reduction signal (0.75 V and 0.64 V, respectively, vs. Ag) of FcDC2- was observed and maintained during forty CV cycles, while the crystallinity of the MOF remained unchanged after the experiment.

Objectives: It is uncertain whether dermal regeneration templates (DRTs) are helpful to reconstruct nasal defects. The aim of this study was to assess whether the aesthetic subunits determine the outcome., Methods: In this unicentric, retrospective study, the surgical procedures and outcomes of patients who received DRTs to reconstruct nasal defects were assessed and compared with the involved aesthetic subunits., Results: DRTs were used for reconstruction of 36 nasal defects in 35 patients with involvement of 76 aesthetic subunits: nasal sidewall (n = 21), nasal ala (n = 13), nasal tip/columella (n = 12, n = 1, respectively), nasal dorsum (n = 12), and extranasal aesthetic areas (n = 17). Fifty-eight nasal and 8 extranasal aesthetic subunits were reconstructed with DRTs, 10 subunits with a flap. Twenty-nine of 36 defects healed without any complications (80.5%). All reconstructed nasal tips/columella and the nasal dorsa healed without any complications. Region-specific complications were retraction of the ala rim (4/12; 33.3% of the patients with involvement of the nasal ala) and the formation of a fistula in the nasal sidewall (1/21; 4.8%). Region-specific complications of extranasal subunits were the development of an ectropium (2/3; 66.7% of the patients with involvement of the lower lid)., Conclusions: DRTs can be helpful to reconstruct nasal defects. However, if the defect involves the aesthetic subunits nasal ala or the infraorbital region, different techniques should be preferred.

Background/aims: The tumor suppressor p53 is rarely mutated in gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) but they frequently show a strong expression of negative regulators of p53, rendering these tumors excellent targets for a p53 recovery therapy. Therefore, we analyzed the mechanisms of a p53 recovery therapy on intestinal neuroendocrine tumors in vitro and in vivo., Methods: By Western blot and immunohistochemistry, we found that in GEP-NEN biopsy material overexpression of MDM2 was present in intestinal NEN. Therefore, we analyzed the effect of a small-molecule inhibitor, nutlin-3a, in p53 wild-type and mutant GEP-NEN cell lines by proliferation assay, flow cytometry, immunofluorescence, Western blot, and by multiplex gene expression analysis. Finally, we analyzed the antitumor effect of nutlin-3a in a xenograft mouse model in vivo. During the study, the tumor volume was determined., Results: The midgut wild-type cell line KRJ-I responded to the treatment with cell cycle arrest and apoptosis. By gene expression analysis, we could demonstrate that nutlins reactivated an antiproliferative p53 response. KRJ-I-derived xenograft tumors showed a significantly decreased tumor growth upon treatment with nutlin-3a in vivo. Furthermore, our data suggest that MDM2 also influences the expression of the oncogene FOXM1 in a p53-independent manner. Subsequently, a combined treatment of nutlin-3a and cisplatin (as chemoresistance model) resulted in synergistically enhanced antiproliferative effects., Conclusion: In summary, MDM2 overexpression is a frequent event in p53 wild-type intestinal neuroendocrine neoplasms and therefore recovery of a p53 response might be a novel personalized treatment approach in these tumors., (© 2017 S. Karger AG, Basel.)

Small cell lung cancer (SCLC) is an aggressive cancer showing a very poor prognosis because of metastasis formation at an early stage and acquisition of chemoresistance. One key driver of chemoresistance is the transcription factor Forkhead box protein M1 (FOXM1) that regulates cell cycle proliferation, maintenance of genomic stability, DNA damage response, and cell differentiation in numerous tumor entities. In this study we investigated the role of FOXM1 in SCLC progression and analyzed the effect of FOXM1 inhibition using two proteasome inhibitors, bortezomib and siomycin A. FOXM1 was strongly expressed in patient-derived SCLC samples (n=123) and its nuclear localization was associated with the proliferation marker Ki-67. Both proteasome inhibitors successfully inhibited FOXM1 expression leading to a significantly reduced proliferation and a decreased mitotic rate along with cell cycle arrest and apoptosis induction. These effects were further enhanced by addition of bortezomib to standard chemotherapy. Treatment of mice bearing chemoresistant SCLC xenografts with bortezomib reduced the mean bioluminescence signal of tumors by 54%. Similarly, treatment with cisplatin as a standard chemotherapy reduced the mean bioluminescence signal of tumors by 58%. However, in combination with standard chemotherapy bortezomib further reduced the mean bioluminescence signal by 93% (p=0.0258). In conclusion, we demonstrate the effect of bortezomib in inhibiting FOXM1 expression and thus in sensitizing resistant SCLC cells to standard chemotherapy. Thus, addition of bortezomib to standard chemotherapy might potently improve SCLC therapy, particularly in an extensive cancer stage., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflicts of interest.

The intercalation of different pyrazines (pyrazine, methylpyrazine, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, trimethylpyrazine and tetramethylpyrazine) into the trans-1,4-cyclohexanedicarboxylate (CDC 2- ) based Al-MOF [Al(OH)(CDC)], denoted as CAU-13, was investigated. The adsorption of the guest molecules into the flexible MOF was carried out from an aqueous solution or via vapour phase adsorption, starting with the hydrated narrow-pore form of the framework [Al(OH)(O 2 C-C 6 H 10 -CO 2 )]·H 2 O (CAU-13-np). The obtained host-guest systems were characterised by thermogravimetry and vibrational spectroscopy and their crystal structures were elucidated using powder X-ray diffraction (PXRD) data. The crystal structures indicate that guest molecules forming hydrogen-bonds with the host framework (pyrazine, methylpyrazine and 2,5-dimethylpyrazine) induce a slight opening of the channels, resulting in a semi-open framework conformation (CAU-13-so). For the bulkier guests 2,3-dimethylpyrazine, trimethylpyrazine and tetramethylpyrazine, only van der Waals interactions can be observed between the host and the guest molecules and a large pore conformation is observed (CAU-13-lp). We carried out in situ PXRD studies using synchrotron radiation during the adsorption of the respective guest molecules from aqueous solutions with various concentrations and at different temperatures. In general, stronger host-guest interactions required milder adsorption conditions while harsher conditions nevertheless accelerated the conversion. The kinetic parameters for the intercalation of pyrazine indicate that the rate limiting step differs, depending on the intercalation temperature.

Human hepatocytes display substantial functional inter-individual variation regarding drug metabolizing functions. In order to investigate if this diversity is mirrored in hepatocytes derived from different human pluripotent stem cell (hPSC) lines, we evaluated 25 hPSC lines originating from 24 different donors for hepatic differentiation and functionality. Homogenous hepatocyte cultures could be derived from all hPSC lines using one standardized differentiation procedure. To the best of our knowledge this is the first report of a standardized hepatic differentiation procedure that is generally applicable across a large panel of hPSC lines without any adaptations to individual lines. Importantly, with regard to functional aspects, such as Cytochrome P450 activities, we observed that hepatocytes derived from different hPSC lines displayed inter-individual variation characteristic for primary hepatocytes obtained from different donors, while these activities were highly reproducible between repeated experiments using the same line. Taken together, these data demonstrate the emerging possibility to compile panels of hPSC-derived hepatocytes of particular phenotypes/genotypes relevant for drug metabolism and toxicity studies. Moreover, these findings are of significance for applications within the regenerative medicine field, since our stringent differentiation procedure allows the derivation of homogenous hepatocyte cultures from multiple donors which is a prerequisite for the realization of future personalized stem cell based therapies.

The resilience of microbial communities to press disturbances and whether ecosystem function is governed by microbial composition or by the environment have not been empirically tested. To address these issues, a whole-ecosystem manipulation was performed in a full-scale activated sludge wastewater treatment plant. The parameter solids retention time (SRT) was used to manipulate microbial composition, which started at 30 days, then decreased to 12 and 3 days, before operation was restored to starting conditions (30-day SRT). Activated sludge samples were collected throughout the 313-day time series in parallel with bioreactor performance ('ecosystem function'). Bacterial small subunit (SSU) rRNA genes were surveyed from sludge samples resulting in a sequence library of >417,000 SSU rRNA genes. A shift in community composition was observed for 12- and 3-day SRTs. The composition was altered such that r-strategists were enriched in the system during the 3-day SRT, whereas K-strategists were only present at SRTs⩾12 days. This shift corresponded to loss of ecosystem functions (nitrification, denitrification and biological phosphorus removal) for SRTs⩽12 days. Upon return to a 30-day SRT, complete recovery of the bioreactor performance was observed after 54 days despite an incomplete recovery of bacterial diversity. In addition, a different, yet phylogenetically related, community with fewer of its original rare members displaced the pre-disturbance community. Our results support the hypothesis that microbial ecosystems harbor functionally redundant phylotypes with regard to general ecosystem functions (carbon oxidation, nitrification, denitrification and phosphorus accumulation). However, the impacts of decreased rare phylotype membership on ecosystem stability and micropollutant removal remain unknown.

Objective/hypothesis: The purpose of this work is to evaluate the performance of an acellular dermal allograft (AlloDerm; LifeCell Corp., The Woodlands, TX) in tympanic membrane (TM) grafting., Study Design: A retrospective review of 20 consecutive tympanoplasty surgeries using temporalis fascia and 20 consecutive procedures using AlloDerm., Methods: The charts of 20 consecutive adults who underwent tympanoplasty surgery were reviewed to evaluate graft take and hearing results. Similarly, 20 consecutive patients who had TM grafting with AlloDerm were reviewed. Pre- and postoperative air-bone gaps (ABG) at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz were compared., Results: There were no graft failures in either the temporalis fascia group or the AlloDerm group. No statistically significant difference was noted in hearing results when comparing the residual conductive loss in both postoperative groups., Conclusions: AlloDerm is a suitable material for TM grafting. This product is especially valuable in revision surgery in which the availability of appropriate autologous grafting material is limited.

Although rare, giant major salivary gland pleomorphic adenomas are among the most astonishing patient presentations. Patients may ignore these slow-growing, benign lesions until significant functional impairment occurs. Complete tumor excision and facial nerve preservation in these cases are challenging requirements and are greatly aided by combined transcervical and transmastoid approaches to these lesions. In the presented case, facial nerve monitoring accurately identified the collateralization between the upper and lower divisions of the facial nerve and allowed the required sacrifice of the lower division without the need for facial nerve grafting or reconstruction. The patient recovered full function of all branches.

The improved survival of patients sustaining massive head injuries has increased the number of temporal bone fractures being managed by otolaryngologists and neurosurgeons. We performed a prospective analysis of 35 patients with head injury with temporal bone trauma. The major emphasis of this study was to investigate the incidence, management, and outcome of facial nerve injury in such patients and to evaluate the importance of electrodiagnostics in the surgical management of the facial nerve. The results of this study indicate an incidence of fracture type, hearing loss, and facial nerve paralysis similar to that already recorded in the literature. This study underscores the importance of evoked electromyography, or electroneuronography, in assessing facial nerve function. Electroneuronography provided the indications for surgical intervention for facial paralysis. All patients having surgery for facial paralysis as determined by electroneuronographic findings had pathology of the facial nerve.

Grafting the tympanic membrane can be successfully accomplished by a number of techniques. The otologic literature is replete with descriptions of methods, materials, and results in myringoplasty. It is generally agreed that whatever method and materials are used to graft the tympanic membrane, the graft take-rate should be at least 90%. The key to obtaining a 90% take rate is not the technique employed, but how well the surgeon performs the technique. This article describes the lateral graft technique with fascia. This is the author's preferred myringoplasty procedure. When properly implicated, the lateral graft technique provides reproducible results in any pathologic condition. Excellent hearing and morphologic results can be obtained with few complications.

Protection of the eye is the primary concern in managing the patient with facial paralysis; however, the aesthetic consequences cannot be overlooked. Lagophthalmos has traditionally been treated with frequent ocular lubrication, medical eye care, and tarsorrhaphy. This approach is fraught with the difficulties of poor patient compliance and unacceptable cosmesis. We suggest a protocol for the complete ocular management with emphasis on immediate rather than delayed surgical rehabilitation as a primary therapy in facial paralysis. Gold weight implantation to the upper lid and tightening of the lower lid at the lateral canthus are simple and reliable procedures that provide immediate functional and aesthetic improvement. This surgical technique has extremely low morbidity and is reversible should facial function return. We have used this protocol in more than 30 patients with excellent results.

This article provides an introduction, anatomic considerations, and description of technique for the performance of electroneurography. Two case studies are provided as illustrations.

The retrofacial air tract is a constant and relevant anatomic landmark for the temporal bone surgeon. By purposefully dissecting this space, one is able to safely identify the facial nerve, endolymphatic sac, and jugular bulb. The retrofacial air tract also provides access to the petrous apex. Forty temporal bones of varying degrees of pneumatization were dissected in order to study the retrofacial air tract. A well-developed air tract was easily identified in all specimens. We describe our anatomic findings and discuss the surgical relevance and important of the retrofacial air tract.

Facial paralysis, although a rare complication of AIDS related complex (ARC) or AIDS, may well be the presenting symptom of HIV positivity. A case report of facial paralysis followed closely by discovery of HIV positivity is described, along with a pertinent and extensive literature review. Seroconversion to HIV-positive status should be suspected in any high-risk patient presenting with idiopathic facial paralysis. HIV testing should be included in the evaluation of Bell's palsy and other idiopathic forms of facial paralysis in the at-risk patient.

Intraoperative facial nerve monitoring with electrical stimulation (IFNMES) has become an integral part of acoustic tumor surgery. We reviewed the records of fifty-six patients who underwent translabyrinthine acoustic tumor removal with IFNMES. There was excellent correlation between intraoperative facial nerve activity and immediate postoperative facial nerve function (24 hours after surgery and at hospital discharge). Our data would suggest that patients who exhibit less than 500 microvolts of ongoing EMG activity during surgery, and who yield at least a 500-microvolt contraction when stimulated with 0.05 milliamps at the brainstem after tumor removal, can expect an excellent immediate facial nerve result (grade I or II).

Tragal perichondrium is a widely used tissue seal in the oval window following stapes surgery. Autogenous and easily accessible, it is a suitable substance to cover the vestibule in total stapedectomy, and to seal around the prosthesis in small-fenestra stapedotomy. The incidence of complications from the use of perichondrium in this manner is exceedingly low. We report a case where tragal perichondrium in the oval window resulted in the proliferation of cartilage. The cartilage displaced the stapes prosthesis, resulting in a conductive loss. Although the chondrogenic potential of perichondrium is known, we are not aware of other reports implicating this as a cause of failure in stapes surgery. The pertinent clinical and experimental literature regarding chondrogenesis is reviewed. This information suggests that the formation of cartilage from perichondrium in the oval window might be influenced by mechanical trauma and tissue orientation.

Most otologists are cautioned at some point in their training that if bone dust is allowed to enter the middle ear while the mastoid is being drilled, there may be adverse consequences. Two cases of ossicular fixation and conductive hearing loss after retrolabyrinthine vestibular nerve section prompted us to examine the issue of bone dust in the middle ear. In a study of 13 temporal bones that had undergone neurotologic surgery, we found 11 that showed evidence of viable bone dust in the middle ear, and three that had ossicular fixation. Viable bone dust was always encased in a mucous membrane lining. These findings suggest that bone dust that enters the middle ear may indeed remain viable and cause ossicular fixation. The surgeon should therefore take every precaution to prevent bone dust from entering the middle ear during neurotologic procedures in which conservation of hearing is attempted.

Intraoperative facial nerve monitoring (FNM) is widely used as a method of assessing the anatomic and physiologic integrity of the facial nerve during procedures in which the nerve may be in jeopardy. The doctors of the Otologic Medical Group use intraoperative FNM during all neurotologic procedures. This technique can also be used for congenital ear surgery and complicated revision chronic ear surgery. On the basis of experience gained from more than 200 cases in which FNM has been used, definitive conclusions can be made in regard to technical aspects. This article will discuss indications for intraoperative FNM, electrode design, visual and auditory feedback, and the particulars about stimulators.

Adenomatous tumors of the middle ear and mastoid have been called adenoma or adenocarcinoma. The clinical and pathologic distinction between the two has been difficult. The resultant pathologic ambiguity makes it difficult to decide whether conservative or radical management is appropriate. The Otologic Medical Group's (OMG) experience with glandular tumors of the middle ear and mastoid over the past 27 years was reviewed. Thirteen cases were found and analyzed with respect to signs and symptoms at presentation. Extensive histopathologic review with light and electron microscopy was performed on tumor specimens. Two distinctive histopathologic and clinical patterns were identified. The mixed type of tumor was always confined to the middle ear and mastoid, was commonly misdiagnosed as chronic otitis media, and rarely demonstrated otic capsule or facial nerve involvement. The papillary pattern always had extension to the petrous apex and frequently involved the middle and/or posterior cranial fossa. Papillary tumors were more frequent in females and usually involved the facial nerve. On the basis of the findings in this review as well as information from the literature, we have come to the following conclusions: 1. The correct general pathologic heading be Adenomatous Tumors of the Middle ear and Mastoid with each tumor then being subclassified into Mixed or Papillary tumor and adenocarcinoma when warranted by histology. 2. There is a high rate of local recurrence. 3. Long-term follow-up (at least 10 years) for all adenomatous tumors is necessary. 4. Primary surgical treatment is required.

Cholesterol granuloma of the petrous apex is an unusual clinical entity that has received much attention in the recent literature. Not considered to be a life-threatening lesion, cholesterol granuloma usually presents with a variety of cranial nerve findings. A case of brainstem compression caused by a giant cholesterol granuloma is presented. This lesion prompted emergency surgical intervention with dramatic relief of neurologic symptoms. The unusual nature of this case is compared with the more common presentation of cholesterol granuloma.

Labyrinthectomy is an effective technique in the surgical treatment of vertigo. We believe that the transmastoid approach is the most direct method of vestibular ablation. This technique provides direct visualization of vestibular neuroepithelium and allows for positive identification of the facial nerve. Vertigo was successfully controlled by this method in thirty-seven (97%) of thirty-eight patients.

Vascular compression syndromes in the posterior cranial fossa have become well described clinical entities, especially for the fifth and seventh cranial nerves. Jannetta has proposed vascular compression of the eighth nerve as the etiology of hearing loss, tinnitus, and vertigo in some patients. The case that follows illustrates a clear-cut example of vestibular symptoms arising from vascular compression of the eighth nerve. The patient involved had disabling peripheral vertigo refractory to medical management. Magnetic resonance imaging documented a tortuous basilar artery compressing the eighth nerve on the involved side. This was confirmed at surgery, and a selective section of the vestibular nerve provided complete relief of disabling symptoms and preservation of hearing. The authors describe the details of this case and the enigma of eighth nerve symptoms due to vascular compression.

Thirty-three (16.5%) of the first 200 patients who presented to the Otologic Medical Group with acoustic tumors underwent surgery for their subtotal removal. These 33 patients, operated on between 1964 and 1967, were followed for clinical evidence of recurrent tumor for a period ranging from 2 to 20 years. Twelve patients required further surgery for recurrent tumor and three of these repeat surgery patients died as a result of their tumors. Case reports of six patients who underwent partial resection are presented with recent computed cranial tomographic follow-up.