OS01.7.A Detection of methylation-based prognostic signatures in liquid biopsy specimens from patients with meningiomas

Background

Detection of distinct epigenetic biomarkers in circulating cell-free DNA (cfDNA) of liquid biopsy (LB) specimens (e.g. blood) fosters opportunity for prognostication of central nervous system (CNS) tumors and has not been thoroughly explored in patients with meningiomas.

Material and Methods

We profiled the cfDNA methylome (EPIC array) in serum specimens from patients with meningiomas (MNG; n= 63) and harnessed internal and external meningioma tissue methylome data with reported follow up (n=48). To predict recurrence risk (RR), we consolidated a tissue cohort with at least 5 years of follow up and divided them into confirmed recurrence (CR; either reported progressive disease in post-surgical imaging, or additional resections following initial surgery) and confirmed no-recurrence (CNR: no confirmed disease progression w/in at least 5-years of follow-up). Then through application of an iterative process consisting of multiple tissue- and serum-based supervised analyses, we identified risk-specific methylation markers with serum specific features which, when inputted into a random forest algorithm allowed for segregation of both tumor tissue and liquid biopsy specimens according to recurrence risk. We estimated immune cell composition using MethylCIBERSORT, where a reference methylome atlas of chosen immune cell types was utilized to deconvolute the MNG samples.

Results

The resulting recurrence risk classifier demonstrated an appreciable predictive power in classifying samples as high or low recurrence risk across the tumor tissue cohort (ACC: 87.5%, CUI+: 85.2%). When compared to another classifier, our model demonstrated statistically significant agreement across primary meningioma samples (κ=0.269, p=0.002), and more accurately predicted samples to recur across an expanded time window (time to recurrence >5yrs). Across resulting liquid biopsy classifications, recurrence risk subgroups were analogous with reported risk factors, including WHO grade, extent of resection, and tumor location. Recurrence risk subgroups (high and low) also demonstrated differential estimated immune cell contributions, with low-risk samples exhibiting a “hot” profile, or enrichment of B-Cells, CD56- and CD4 T-Cells, and natural killer cells. Notably, the estimated neutrophil to lymphocyte ratio, previously purported to be relevant to tumor prognosis, was appreciably higher for those meningioma samples with the highest recurrence risk.

Conclusion

DNA methylation markers identified in the serum are suitable for the development of machine learning-based models which present high predictive power to prognosticate patients with meningioma and estimate a differential immune profile across recurrence risk groups. After validation in an external cohort, this noninvasive approach may improve the presurgical therapeutic management of patients with meningiomas.

OS08.3.A Distinct systemic and tumor microenvironment immune landscapes discriminate across sellar tumor types and controls through a methylation-based deconvolution method

Background

Systemic (Sys) and tumor microenvironment (TME) immune milieus play a pivotal role in tumor development, outcome and immunotherapy response predictions across a variety of central nervous system tumors. Genome-wide methylation profiling can reliably discriminate and estimate immune cell proportions present in the blood and within the tumor and has not been reported across sellar tumor types (STT).

Material and Methods

We estimated cell composition in liquid biopsy (LB, serum/plasma) and tissue specimens from 42 STT collections (i.e., pituitary neuroendocrine tumors [PitNETs; n=37] and craniopharyngiomas [CP; n=5]), and 26 nontumor controls (LB: 11; Tissue: 15) using MethylCIBERSORT, a methylation-based deconvolution algorithm and established immune cell signatures as reference. LB methylation was profiled with EPIC array. Correlations between estimated cell proportions across sample sources were explored (Spearman). Immune cell proportion hierarchical k-means clustering was performed across tissue and LB specimens. Similarly, mean comparisons between and across sample types and subgroups of interest were performed [Non-parametric Kruskal-Wallis, Wilcoxon rank-sum tests; p<0.05].

Results

We identified three immune-clusters across tissue specimens which distinguished controls (k3-cluster) from sellar tumor specimens (k1- and k2- clusters), primarily attributable to differential B-cell and monocyte proportions. Interestingly, a subset of PitNET and CP, belonging to the k2-cluster, presented a distinct immune profile compared to their K1-sellar tumor counterparts. Analysis of plasma-derived immune clusters revealed that PitNETs were distributed across four distinct immune patterns and CP clustered together with controls and a PitNET subset. One of the PitNET clusters was enriched with patients that died during follow-up and presented an enrichment of CD4-(including the regulatory subtype), CD8 and CD56-T and depletion of natural killer cells. Differences across serum- and tissue-derived clusters were present but less prominent than their plasma counterparts. No correlation between immune cell proportions across other clinicopathological features within each tumor type (sex, age, histotypes, invasion etc) was observed.

Conclusion

Our results suggest that PitNETs are characterized by differential TME and systemic immune subtypes which also distinguish these tumors from CP and controls. Additionally, distinct systemic immune composition between tissue and LB sources, more readily observed in plasma, suggest that the systemic response to the presence of the tumor is distinct from the immune response noted in the TME. Tumor immune subtyping may allow the stratification of STT according to immunotherapy response vulnerabilities.

P01.02 Serum-derived DNA methylation markers distinguish functional and invasiveness subtypes in patients harboring pituitary tumors

BACKGROUND

Molecular profiling of circulating biomarkers released by tumors has a relevant clinical value in central nervous system (CNS) tumors, but its feasibility has not been investigated in pituitary tumors (PT) despite being the second common intraaxial tumors of the CNS (~15%). Although usually benign and slow-growing, they can be nonfunctioning and invade surrounding structures resulting in significant comorbidities. DNA methylation aberrations distinguish PT according to their functional status but their role in invasiveness is still unclear. Pre-surgical detection of clinically relevant molecular markers associated with tumor behavior can address current diagnostic and therapeutic challenges. We hypothesized that PT release cell-free DNA (cfDNA) into the bloodstream allowing for the profiling of epigenetic markers associated with relevant clinicopathological features.

MATERIAL AND METHODS

Genome-wide methylome profile of paired serum cfDNA (EPIC array) and tissue from 13 patients with pituitary macroadenomas (9 males; median age: 62; 9 NFPT, 6 invasive) and 3 controls serum (patients with epilepsy).

RESULTS

Unsupervised analysis of the serum methylome from patients harboring PT was distinct from controls and other diseases (hypopituitarism, glioma and colorectal cancer) and supervised analysis (Wilcoxon Rank-sum Test) identified significant differentially methylated probes (DMP) that segregated PT from control serum specimens. Nonfunctioning and invasive-specific DMPs identified in the serum also defined functional, and less prominently invasive status, in the tissue of an independent cohort of PT.

CONCLUSION

This is the first study to show the feasibility to profile the methylome in the serum of patients with PT using cfDNA. In addition, we identified unique methylation signatures that distinguished PT according to functional and invasiveness subtypes. These results underpin the potential role of methylation profile and liquid biopsy as a noninvasive approach to assess clinically relevant molecular features in the serum of patients harboring PT.

OS1.5 Detection of glioma and prognostic subtypes by non-invasive circulating cell-free DNA methylation markers

BACKGROUND: Genome-wide DNA methylation profiling has shown that epigenetic abnormalities are biologically important in glioma and can be used to classify these tumors into distinct prognostic groups. Thus far, DNA profiling has required surgically resected glioma tissue; however, gliomas release tumoral material into biofluids providing an opportunity for a minimally invasive testing. While prior studies have shown that molecular markers can be detected in liquid biopsy (LB), there has been low sensitivity for tumor-specific markers. We hypothesize that the low sensitivity is due to the targeted assay methods. METHODS: Genome-wide CpG methylation levels in DNA of tumor tissue and cell-free DNA serum of glioma patients. RESULTS: We defined glioma-specific and IDH-specific epigenetic LB (eLB) signatures (Glioma-eLB and IDH-eLB, respectively) from serum cell-free DNA from patients diagnosed with glioma (N=15 IDH mutant and N=7 IDH wildtype) and with epilepsy (N=3). The epigenetic profiles of the matched tissue demonstrate that these eLB signatures reflected the signature of the tumor. Through cross-validation we show that Glioma-eLB can accurately predict a patient’s glioma from those with other neoplasias (N=6 Colon; N=14 Pituitary; N=3 Breast; N=4 Lung), non-neoplastic immunological conditions (N=22 sepsis; N=9 pancreatic islet transplantation), and from healthy individuals (sensitivity: 98%; specificity: 99%). Finally, IDH-eLB includes promoter methylated markers associated with genes known to be involved in glioma tumorigenesis (PVT1 and CXCR6). CONCLUSIONS: The application of the non-invasive eLB signature discovered in this study has the potential to complement the standard of care for patients harboring glioma.

This project is supported by the Henry Ford Health System, Department of Neurosurgery and the Hermelin Brain Tumor Center Foundation (A30935), United States National Institutes of Health (R01CA222146), and United States Department of Defense (CA170278)

P13.15 DNA methylation abnormalities in non-promoter regulatory regions are associated with invasive behavior in pituitary tumors

BACKGROUND

Despite histologically benign, pituitary tumors (PT) may invade important adjacent neurovascular structures which can incur in significant comorbidities preventing a complete surgical resection and contributing to resistance to medical treatment. DNA methylation clearly stratified PT based on their functional status i.e. nonfunctioning PTs (NFPTs) from functioning PT (FPTs). However associations of methylation aberrations with invasive behavior is less clear.

MATERIAL AND METHODS

In order to evaluate whether DNA methylation alterations in regulatory regions other than promoter and coding regions are associated with invasive behavior we performed a meta-analysis of the genome-wide methylome of three public available PT cohorts plus our own (Illumina HumanMethylation platforms- 450K/EPIC). Pituitary specimens comprised of 43 invasive pituitary tumors (InvPT) and 37 noninvasive (NInvPT); 12 FPT and 68 NFPTs, in addition to 20 non-tumor pituitaries. RNA-seq data were available for one cohort (n=23, 12 InvPT,11NInvPT) and integrated with DNA methylation. Invasiveness criteria was based on Knosp grade >= 2 and/or sphenoid or dural invasion.

RESULTS

Wilcoxon Rank-sum test; Δβ=0.15; p-value <0.001 identified 58 differentially methylated CpG sites in InvPT that were mainly hypomethylated (95%) in relation to NInvPT. NInvPT methylation profile was similar to non-tumor specimens, despite its heterogeneity. Thirty-four percent (n=20) of the differentially methylated CpG sites were located within predicted enhancer regions distributed in intronic (40%), intergenic (40%) and promoter (20%) regions. Predicted enhancer-target genes were enriched for actin filament cell movement, response to starvation, growth factor stimulus and protein autophosporilation pathways. Among them, ZNF625 and INO80E were found mostly negative correlated among methylation and expression data (-0.50 and -0.48, respectively), besides DOC2A found to be one potentially differentially expressed gene under enhancer control (log2FC > 0.2, pvalue <0.05).

CONCLUSION

Our results suggest that methylation alterations in predicted regulatory regions, such as enhancers, annotated in non-promoter regions (introns and intergenic) may contribute to the invasive behavior of PT.

A phase II and pharmacodynamic study of sunitinib in relapsed/refractory oesophageal and gastro-oesophageal cancers

BACKGROUND

Blockade of the vascular endothelial growth factor (VEGF) pathway shows evidence of activity in gastro-oesophageal (GE) and oesophageal cancer. We investigated the efficacy of sunitinib, a multikinase VEGF inhibitor, in patients with relapsed/refractory GE/oesophageal cancer.

METHODS

This was a single-stage Fleming phase II study. The primary end point was progression-free survival (PFS) at 24 weeks. If five or more patients out of a total of 25 were free of progressive disease at 24 weeks, sunitinib would be recommended for further study. Patients received sunitinib 37.5 mg orally daily and imaged every 6 weeks. Exploratory correlative analysis included serum growth factors, tumour gene expression and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

RESULTS

Twenty-five evaluable patients participated in the study. Progression-free survival at 24 weeks was 8% (n=2 patients; confidence interval (CI): 95% 1.4-22.5%), and the duration of best response for the patients was 23 and 72 weeks. Ten patients (42%) had stable disease (SD) for >10 weeks. Overall response rate is 13%. Median PFS is 7 weeks (95% CI: 5.6-11.4 weeks) and the median overall survival is 17 weeks (95% CI: 8.9-25.3 weeks). Most common grade 3/4 toxicities included fatigue (24%), anaemia (20%) thrombocytopenia (16%), and leucopenia (16%). No patients discontinued therapy due to toxicity. Serum VEGF-A and -C levels, tumour complement factor B (CFB) gene expression, and DCE-MRI correlated with clinical benefit, defined as SD or better as best response.

CONCLUSION

Sunitinib is well tolerated but only a select subgroup of patients benefited. Serum VEGF-A and -C may be early predictors of benefit. On this study, patients with clinical benefit from sunitinib had higher tumour CFB expression, and thus has identified CFB as a potential predictor for efficacy of anti-angiogenic therapy. These findings need validation from future prospective trials.

Characterisation of myosin heavy chain gene variants in the fast and slow muscle fibres of gammarid amphipods

Recent molecular work has revealed a large diversity of myosin heavy chain (MyHC) gene variants in the abdominal musculature of gammarid amphipods. An unusual truncated MyHC transcript from the loop 1 region (Variant A(3)) was consistently observed in multiple species and populations. The current study aimed to determine whether this MyHC variant is specific to a particular muscle fibre type, as a change in net charge to the loop 1 region of Variant A(3) could be functionally significant. The localisation of different fibre types within the abdominal musculature of several gammarid species revealed that the deep flexor and extensor muscles are fast-twitch muscle fibres. The dorsal superficial muscles were identified as slow fibres and the muscles extrinsic to the pleopods were identified as intermediate fibres. Amplification of loop 1 region mRNA from isolated superficial extensor and deep flexor muscles, and subsequent liquid chromatography and sequence analysis revealed that Variant A(3) was the primary MyHC variant in slow muscles, and the conserved A(1) sequence was the primary variant in fast muscles. The specific role of Variant A(3) in the slow muscles remains to be investigated.

Single fraction radiosurgery of epidural spinal cord compression: Tumor control and neurologic outcome

2041

Purpose: Spine radiosurgery improves the pain and quality of life in spine metastasis. Phase II study was performed to determine the clinical efficacy of radiosurgery for malignant epidural spinal cord compression. Method: Total 67 patients with 93 lesions of epidural spinal cord compression at the solitary spine level were accrued. All patients had pathology-proven malignancy and had epidural tumor seen on MRI or CT scan. For radiosurgery, grossly visible tumor including the involved spine was treated with single fraction radiosurgery dose of 14–20 Gy. Spinal cord dose constraint was 10 Gy to 10% partial volume of the cord. Followup included neurological exam and imaging studies every 2 months. Endpoints were radiographic tumor control and neurological outcome. Median followup time was 8 months (2–30 months). Results: Objective radiographic tumor response was seen in 82% of patients. At 2 months, complete response was in seen 27%, partial response in 30%, and minimal response in 23%, Epidural tumor progressed in 6% at or the adjacent spine level. Thecal sac patency (= decompression effect) seen on T2-weighted MR image was improved in 82% of the lesions. There was average 68% volumetric reduction of tumor at the level of most severe cord compression. This tumor reduction opened the thecal sac patency to average 75% following radiosurgery, compared to 45% before radisourgery (p<0.05). Majority of patients with neurological deficit prior to radiosurgery were ambulatory with an improved neurological function or remained clinically stable. There was one case of likely long-term radiation-induced myelopathy 13 months after radiosurgery. Conclusion: Single fraction radiosurgery achieves significant tumor response and decompressive effect of spinal cord compression. Even minimal tumor response relieves the spinal cord compression and potential neurologic improvement. Spine radiosurgery can be a viable treatment option for spinal cord compression.

No significant financial relationships to disclose.

Phylogeography and environmental diversification of a highly adaptable marine amphipod, Gammarus duebeni

Genetic diversity and phylogeographic population structure in the gammarid amphipod, Gammarus duebeni, were investigated across its broad latitudinal distribution in the NE and NW Atlantic by analysis of mitochondrial DNA sequence. Gammarus duebeni has exceptional tolerance of salinity change and inhabits environments ranging from marine to freshwater. The longstanding debate on whether there are distinct marine and freshwater subspecies was assessed by sampling populations from sites characterized by different salinities. Our sequence data demonstrates that there are two major lineages, with little internal geographic structuring. Evidence is provided to suggest a pre-glacial divergence of these two clades, involving segregation between a region historically associated with the freshwater form and the majority of the marine localities on both sides of the Atlantic. A modern contact zone between the marine and freshwater forms is proposed in western Britain.

Organization of the respiratory chain of Neisseria meningitidis

The ability of Neisseria meningitidis to utilize both oxygen and nitrogen oxides as respiratory substrates allows it to thrive in the diverse environment of the human host. Genome analysis highlighted genes encoding a cbb(3) cytochrome oxidase, the aniA nitrite reductase gene and the norB nitric oxide reductase gene. In the present study, we used myxothiazol as an inhibitor of the bc(1) complex in intact cells and demonstrated that electron flow to nitrite reductase and the cytochrome oxidase, but not NO reductase, passes via the cytochrome bc(1) complex. UV-visible spectrophotometry of intact cells demonstrated that oxygen oxidizes c-type and b-type cytochromes. Oxidation of cytochromes by nitrite was only seen in microaerobically precultured whole cells, and the predominant oxidizable cytochromes were b-type. These are likely to be associated with the oxidation of a b-haem-containing nitric oxide reductase. Nitrite inhibits the oxidation of cytochromes by oxygen in a nitrite reductase-independent manner, indicating that nitrite may inhibit oxidase activity directly, as well as via the intermediate of denitrification, nitric oxide.

Retrospective review of MEG visual evoked hemifield responses prior to resection of temporo-parieto-occipital lesions

Visual evoked cortical magnetic field (VEF) waveforms were recorded from both hemifields in 21 patients with temporo-parieto-occipital mass lesions to identify preserved visual pathways. Fifteen patients had visual symptoms pre-operatively. Magnetoencephalographic (MEG) VEF responses were detected, using single equivalent current dipole (ECD), in 17/21 patients studied. Displaced or abnormal responses were seen in 15 patients with disruption of pathway in one patient. Three of 21 patients had alterations in the surgical approach or the planned resection based on the MEG findings. The surgical outcome for these three patients suggests that the MEG study may have played a useful role in pre-surgical planning.

[MR angiography of pelvic and leg vessels with automatic table movement technique ("Mobi-Trak")--clinical experience with 450 studies]

PURPOSE

By a retrospective clinical evaluation of 450 MR angiograms of the lower extremity arteries the question was posed of whether MR angiography can replace i.a. DSA.

MATERIAL AND METHODS

Image quality of 450 MR angiograms was graded by 4 radiologists; in 102 patients who underwent radiological intervention a comparison between MR angiogram and i.a. DSA was done. Additionally, MR angiography was compared with the results of surgical intervention in 106 cases.

RESULTS

6% of 450 examinations showed a significant limitation of diagnostic information. 5 examinations (1%) had to be redone by i.a. DSA. In all cases the diagnosis from MRA was proven by the results of the following i.a. DSA or surgical procedure.

CONCLUSION

The retrospective clinical evaluation of 450 examinations demonstrated that MR angiography of the lower extremity arteries can replace i.a. DSA in routine use.

Effects of reproductive condition, season, and site on selected temperatures of a viviparous gecko

The relationship between thermal and reproductive biology is complex and poorly understood. We measured selected body temperatures (T(sel)) for the viviparous gecko Hoplodactylus maculatus. T(sel) was compared among pregnant females, nonpregnant females, and males from two sites: a cool site with biennially reproducing geckos and a warm site with annually reproducing geckos. T(sel) was measured at five times of day during three seasons and compared with microhabitat temperature (T(top)) and field body temperature (T(b)). T(sel) varied with time of day in all comparisons, and the effect of reproductive condition on T(sel) differed between sites and seasons. At both sites, when T(sel) differed between reproductive conditions, pregnant females had higher T(sel) than nonpregnant females and males. Stage of pregnancy affected the degree of elevation of T(sel). Measurements of microhabitat temperature and field T(b) showed that, even in the warmest season, geckos rarely had the opportunity to achieve T(sel) at the cool site but were able to do so at the warm site. The elevation of T(sel) with pregnancy is extreme in this species (up to 8 degrees C), which suggests that an increase in T(b) is critical to successful reproduction. Interactions between the effects of time of day, season, and reproductive condition on T(sel) must be considered in the assessment of thermoregulation in reptiles.

Anterior lumbar fusion with titanium threaded and mesh interbody cages

The authors report their experience with 42 patients in whom anterior lumbar fusion was performed using titanium cages as a versatile adjunct to treat a wide variety of spinal deformity and pathological conditions. These conditions included congenital, degenerative, iatrogenic, infectious, traumatic, and malignant disorders of the thoracolumbar spine. Fusion rates and complications are compared with data previously reported in the literature. Between July 1996 and July 1999 the senior authors (C.I.S., R.P.N., and M.J.R.) treated 42 patients by means of a transabdominal extraperitoneal (13 cases) or an anterolateral extraperitoneal approach (29 cases), 51 vertebral levels were fused using titanium cages packed with autologous bone. All vertebrectomies (27 cases) were reconstructed using a Miami Moss titanium mesh cage and Kaneda instrumentation. Interbody fusion (15 cases) was performed with either the BAK titanium threaded interbody cage (in 13 patients) or a Miami Moss titanium mesh cage (in two patients). The average follow-up period was 14.3 months. Seventeen patients had sustained a thoracolumbar burst fracture, 12 patients presented with degenerative spinal disorders, six with metastatic tumor, four with spinal deformity (one congenital and three iatrogenic), and three patients presented with spinal infections. In five patients anterior lumbar interbody fusion (ALIF) was supplemented with posterior segmental fixation at the time of the initial procedure. Of the 51 vertebral levels treated, solid arthrodesis was achieved in 49, a 96% fusion rate. One case of pseudarthrosis occurred in the group treated with BAK cages; the diagnosis was made based on the patient's continued mechanical back pain after undergoing L4-5 ALIF. The patient was treated with supplemental posterior fixation, and successful fusion occurred uneventfully with resolution of her back pain. In the group in which vertebrectomy was performed there was one case of fusion failure in a patient with metastatic breast cancer who had undergone an L-3 corpectomy with placement of a mesh cage. Although her back pain was immediately resolved, she died of systemic disease 3 months after surgery and before fusion could occur. Complications related to the anterior approach included two vascular injuries (two left common iliac vein lacerations); one injury to the sympathetic plexus; one case of superficial phlebitis; two cases of prolonged ileus (greater than 48 hours postoperatively); one anterior femoral cutaneous nerve palsy; and one superficial wound infection. No deaths were directly related to the surgical procedure. There were no cases of dural laceration and no nerve root injury. There were no cases of deep venous thrombosis, pulmonary embolus, retrograde ejaculation, abdominal hernia, bowel or ureteral injury, or deep wound infection. Fusion-related complications included an iliac crest hematoma and prolonged donor-site pain in one patient. There were no complications related to placement or migration of the cages, but there was one case of screw fracture of the Kaneda device that did not require revision. The authors conclude that anterior lumbar fusion performed using titanium interbody or mesh cages, packed with autologous bone, is an effective, safe method to achieve fusion in a wide variety of pathological conditions of the thoracolumbar spine. The fusion rate of 96% compares favorably with results reported in the literature. The complication rate mirrors the low morbidity rate associated with the anterior approach. A detailed study of clinical outcomes is in progress. Patient selection and strategies for avoiding complication are discussed.

Characteristics of female obstetrician-gynecologists in the United States

OBJECTIVE

To describe characteristics of United States female obstetrician-gynecologists, a large and growing group, and to contrast them with other female physicians.

METHODS

We contrasted data from 313 obstetrician-gynecologists to data from 4132 other female physician respondents to the Women Physicians' Health Study, a national questionnaire-based study.

RESULTS

Obstetrician-gynecologists assumed fewer domestic responsibilities, reported higher personal and household incomes, and were more likely to be in a group practice than other female physicians. Female obstetrician-gynecologists' personal health behaviors and other personal characteristics, career satisfaction, and desire to remain in their specialty were similar to those of other female physicians. Obstetrician-gynecologists did more counseling and screening than primary care physicians (family and general practitioners and internists) with respect to breast cancer and hormone replacement therapy (HRT). Obstetrician-gynecologists performed equivalently to primary care physicians with respect to human immunodeficiency virus (HIV), colorectal cancer, blood pressure, weight, exercise, and smoking, performed like other specialists with respect to cholesterol, skin cancer, and flu vaccine, and between these two groups with respect to nutrition and alcohol. Obstetrician-gynecologists' perceived relevance of, training in, and confidence regarding counseling were higher for HRT and breast cancer compared with other physicians.

CONCLUSION

Obstetrician-gynecologists have many similarities with other female physicians, including level of career satisfaction, but earned more and assumed fewer domestic responsibilities. Although obstetrician-gynecologists counseled more than other specialists, with the increasing role of obstetrician-gynecologists as primary care doctors, it is noteworthy that female obstetrician-gynecologists frequently provide gynecologic-specific preventive care, but are less likely to address other non-obstetric-gynecologic areas of prevention. This finding could be transformed by continued changes in the education of residents and practicing physicians.

Recovery nystagmus revisited

Recovery nystagmus (RN) describes a spontaneous nystagmus with a fast-phase beating toward the ipsilesional ear. The mechanisms underlying RN implicate central vestibular system compensation processes. The presence of RN is significant because it implies that function has returned from the affected peripheral vestibular system. A case is described where RN was recorded. The processes underlying RN are described.

Palliation of recurrent endometriosis with radiotherapeutic ablation of ovarian remnants

OBJECTIVE

To review the use of radiotherapy for relieving the symptoms of recurrent endometriosis caused by functioning ovarian remnants.

DESIGN

Retrospective study (case report).

PATIENT(S)

A woman with recurrent endometriosis of 14 years' duration.

INTERVENTION(S)

After hysterectomy and bilateral oophorectomy, hormonal management, and multiple explorations for recurrent endometriosis, cycling ovarian remnants were confirmed histologically. Pelvic irradiation was used to ablate this tissue. A dose of 15 Gy in 10 daily fractions was given through anterior and posterior opposed fields using 18-mV photons.

RESULT(S)

The patient had a prompt increase in FSH levels associated with castration levels of serum E2. A review of the literature on the use of radiotherapy in this clinical situation is presented.

CONCLUSION(S)

Radiotherapy should be considered in selected patients when ovarian castration is not a viable surgical option and hormonal therapies have failed.

Karyotype and nuclear DNA content of the Australian lungfish, Neoceratodus forsteri (Ceratodidae: Dipnoi)

The karyotype of the lungfish, Neoceratodus forsteri, is described as 2n = 54, comprising 3 pairs of very large metacentrics, 1 pair of large submetacentrics, 13 pairs of smaller acrocentrics, and 10 pairs of microchromosomes. In addition to centromeric constitutive heterochromatin, C-bands were located on the arms of almost all of the macrochromosomes. The nuclear DNA content of N. forsteri was confirmed as being high (98.6-111.9 pg/nucleus).

Spontaneous atlantoaxial osteomyelitis: no longer a rare case? Case report

The number of case reports concerning anterior atlantoaxial osteomyelitis has increased in the past decade. Although previously considered rare, this particular disease has become more prevalent for several reasons, including the increase in the elderly population, which is generally more susceptible to infectious problems. It is, therefore, imperative for physicians in general and neurosurgeons in particular to become aware of the existence of this problem and of the therapeutic options available.