P14.34 Long-term seizure outcomes and tumor recurrence after glioneural tumor surgery: A single-center retrospective cohort

BACKGROUND

Gangliogliomas (GG) and dysembryoplastic neuroepithelial tumors (DNET) are glioneural tumors associated with treatment refractory seizures, especially in younger patients. Because there is a relative paucity of data on which factors predispose patients for recurrences, we analyzed our own cohort treated over the last 25 years.

MATERIAL AND METHODS

We performed a retrospective analysis of all patients undergoing resection of a glioneural tumor with a minimum follow up of one year. Surgery type, histological findings, and seizure outcome were extracted from patient records. Recurrence was defined as new tumor lesions in previously unremarkable parenchyma or tumor growth of a residual lesion. We performed a Mann-Whitney-U test to determine statistical significance of differences in continuous variables and Fisher’s exact test in categorical.

RESULTS

In total, 109 patients were operated between March 1994 to March and followed for a median of 62.4 months (range 12–281 months). The average age of patients at the time of surgery was 21.2 years with 60 patients belonging to the pediatric population. Complete lesionectomies were the goal in 72 cases, extended resections in 10, and partial resection due to proximity of eloquent areas was performed in 27 cases. 77 tumors were classified histologically as a GG and 32 as a DNET. The temporal lobe was the most common site of origin with 65 tumors (59.6%) being found there. On postoperative MRI, complete resection was achieved in 76 cases. Local tumor recurrences were seen in 14 patients (12 GG and 2 DNET), 9 of which occurred in patients with apparently complete resection. Overall, only one malignant transformation of a GG was observed. Age at surgery was significantly lower for patients with later recurrence (11.9 yrs vs. 22.6 yrs for patients without recurrence, p=0.0047). A second surgery was performed in 11 patients with previously incomplete resections (33%) and 7 patients with complete resection (9.2%), p=0.0038. 95 patients (87.2%) had preoperative seizures for a median of 26 months before surgery. One year after surgery, a documented ILAE outcome was available for 90 of these patients and 63 (70%) were seizure free one year after surgery. While 45 patients with epilepsy (47.4%) had at least one seizure relapse after surgery - most often associated with AED withdrawal or tumor recurrence - medical therapy and repeat resection allowed 76 patients (80%) to be seizure free for over one year at their last follow up. Age at surgery was not a significant predictor of seizure freedom.

CONCLUSION

Glioneural tumors are highly epileptogenic but neurosurgical resection allows seizure freedom in the large majority of these patients. Tumor recurrences were more likely in younger patients and incomplete resections predisposed patients to need another surgery. Resection extent on MRI does not appear to be a reliable marker for future recurrence risk.

Ten questions concerning the implications of carpet on indoor chemistry and microbiology

Carpet and rugs currently represent about half of the United States flooring market and offer many benefits as a flooring type. How carpets influence our exposure to both microorganisms and chemicals in indoor environments has important health implications but is not well understood. The goal of this manuscript is to consolidate what is known about how carpet impacts indoor chemistry and microbiology, as well as to identify the important research gaps that remain. After describing the current use of carpet indoors, questions focus on five specific areas: 1) indoor chemistry, 2) indoor microbiology, 3) resuspension and exposure, 4) current practices and future needs, and 5) sustainability. Overall, it is clear that carpet can influence our exposures to particles and volatile compounds in the indoor environment by acting as a direct source, as a reservoir of environmental contaminants, and as a surface supporting chemical and biological transformations. However, the health implications of these processes are not well known, nor how cleaning practices could be optimized to minimize potential negative impacts. Current standards and recommendations focus largely on carpets as a primary source of chemicals and on limiting moisture that would support microbial growth. Future research should consider enhancing knowledge related to the impact of carpet in the indoor environment and how we might improve the design and maintenance of this common material to reduce our exposure to harmful contaminants while retaining the benefits to consumers.

A work group report on ultrafine particles (American Academy of Allergy, Asthma & Immunology): Why ambient ultrafine and engineered nanoparticles should receive special attention for possible adverse health outcomes in human subjects

Ultrafine particles (UFPs) are airborne particulates of less than 100 nm in aerodynamic diameter. Examples of UFPs are diesel exhaust particles, products of cooking, heating, and wood burning in indoor environments, and, more recently, products generated through the use of nanotechnology. Studies have shown that ambient UFPs have detrimental effects on both the cardiovascular and respiratory systems, including a higher incidence of atherosclerosis and exacerbation rate of asthma. UFPs have been found to alter in vitro and in vivo responses of the immune system to allergens and can also play a role in allergen sensitization. The inflammatory properties of UFPs can be mediated by a number of different mechanisms, including the ability to produce reactive oxygen species, leading to the generation of proinflammatory cytokines and airway inflammation. In addition, because of their small size, UFPs also have unique distribution characteristics in the respiratory tree and circulation and might be able to alter cellular function in ways that circumvent normal signaling pathways. Additionally, UFPs can penetrate intracellularly and potentially cause DNA damage. The recent advances in nanotechnology, although opening up new opportunities for the advancement of technology and medicine, could also lead to unforeseen adverse health effects in exposed human subjects. Further research is needed to clarify the safety of nanoscale particles, as well as the elucidation of the possible beneficial use of these particulates to treat disease.

A study of women on long-term hormone replacement therapy and their attitude to suggested cessation

OBJECTIVE

The study was undertaken to determine the effect of advice to discontinue hormone replacement therapy (HRT) on 100 women who were well established on treatment without side-effects.

METHOD

The study was retrospective from November 2003 to April 2004, in a single gynecological practice in London, UK. One hundred consecutive long-term estrogen and testosterone hormone implant users were assessed as to their knowledge of recent studies regarding risks of long-term HRT and whether they wished to discontinue hormones.

RESULTS

All women receiving estrogen and testosterone implants, for a mean duration of 17.65 years (range 10-28 years), felt well informed concerning the Women's Health Initiative Study and the Million Women Study but only three women were happy to discontinue. The reasons given for the continuation of therapy were that they felt well and their quality of life had greatly improved. The mean estradiol and testosterone levels were 921 pmol/l and 1.91 nmol/l, respectively.

CONCLUSIONS

The high rate of continuation of hormone treatment indicates that, despite the recent adverse publicity, these women feel well informed and were not willing to discontinue with their hormone therapy if they felt well. A regular discussion of the risks and benefits of HRT remains mandatory.

[Medical abortion with mifepristone and misoprostol: study of the efficacy, somatic tolerance and perception of medical abortion]

STUDY DESIGN

This prospective study examined the efficacy and somatic tolerance as well as the perception of the different phases of medical abortion with mifepristone and misoprostol. The subjective influence of counseling and accompanying on perception and psychic sequelae was evaluated.

METHOD

The somatic data of the patients who had a medical abortion at Basel University Hospital of Gynecology and Obstetrics from December 1, 1999, to October 31, 2000, were identified in the case records. A questionnaire at the time of the abortion and a structured interview by telephone 6 months later were used to assess the perception of the abortion.

RESULTS

Abortion with mifepristone and misoprostol was successful in 95.2% of cases. Counseling and accompanying were considered supportive by 90.4 and 73.7%, respectively. The psychological workup was without problems in 95.5%.

CONCLUSION

Medical abortion with mifepristone and misoprostol was successful in 95.2%. Our concept of counseling and accompanying was well received and resulted in an uneventful psychological workup in most cases.

Differential gene expression in rats following subacute exposure to the anticonvulsant sodium valproate

Sodium valproate (VPA) is clinically employed as an anticonvulsant and, to a lesser extent, as a mood stabilizer. While the incidence of toxicity associated with the clinical use of valproate is low, serious hepatotoxicity makes up a significant percentage of these rare adverse effects, with fatalities occurring mainly in children receiving polypharmacy. Previous studies have highlighted the different pharmacological effects of acute valproate exposure, a combination of which are likely to underpin its observed broad-spectrum anticonvulsant efficacy. However, limited studies have been undertaken to investigate the subacute effects of this compound and how genomic effects may underlie the observed hepatotoxic effects. Investigation into the mild hepatoxicity observed in rats exposed to high doses of VPA may provide important information on the human situation. Male Sprague-Dawley rats were dosed with 500 mg/kg/day sodium valproate: after necropsy, mRNA was subjected to suppression PCR subtractive hybridization, identifying 8 up-regulated and 14 down-regulated mRNA species. The down-regulation of several mRNA species coding for enzymes involved in cellular energetics (e.g., succinate dehydrogenase, aldolase B) was of particular interest, as mitochondrial dysfunction is a key feature of valproate hepatotoxicity. In vitro studies were then undertaken to examine the dose and time dependence of these changes and also their effect on the overall energy levels within the cell. We demonstrate that, both in vivo and in vitro, valproate exposure in rats results in a significant decrease in pathways involved in cellular energy homeostasis. These changes may provide insight into the rare human hepatoxicity associated with this compound.

[Pregnancy outcome in 1,252 fetuses after nuchal translucency measurement in the 1st trimester]

The measurement of the nuchal translucency is an important marker to detect a vast number of fetal anomalies. Lately the nuchal translucency has been used increasingly as a screening method to find chromosomal anomalies especially for trisomy 21. Beside a high incidence of chromosomal defects one assumes a high risk of rare syndromes and other associated anomalies such as heart defects, skeletal anomalies, cerebral anomalies, diaphragmatic hernias, as well as of an intrauterine death. In view of abortion rate, detection rate of chromosomal anomalies, other fetal anomalies and rare syndromes we evaluated in this study the pregnancy outcome after nuchal translucency measurement, and discuss a concept for its management.

Ventricular and parenchymal surface before and after shunting--do they have prognostic value for outcome?

PATIENTS AND METHODS

26 consecutive patients with early hydrocephalus (median age at shunting 2.5 months) were followed up to the age of 3 years, prospectively. The work-up included: regular evaluation of psychomotor development and CT/MRI prior and 6 months following surgery. The latter with measurement of the area of the ventricles (degree of hydrocephalus) and the area of the hemispheres in cm(2) (area of hemispheres minus area of ventricles = parenchymal area and degree of brain mass) at the level of the slice with the largest area of the ventricles.

RESULTS

16 (62 %) had normal development (= Group A) and 10 (38 %) moderate or severe retardation (= Group B). The mean ventricular surface was 25.4 cm(2) in Group A and 31.2 cm(2) in Group B prior to surgery (p = 0.1) and 8.9 versus 14.1 cm(2) postsurgery (p = 0.2). The percentage decrease postoperatively was 59.9, versus 57.1 % (p = 0.4). The percentage of ventricular surface in relation to the hemispheres prior to surgery was 42.2 versus 51.4 % (p = 0.1) and post-surgery 12.8 versus 22.4 % (p = 0.1). The mean parenchymal surface was 34.9 cm(2) in Group A and 29.0 cm(2) in Group B prior to surgery (p = 0.3) and 60.9 versus 48.1 cm(2) post surgery (p = 0.07). Percentage increase was 87.3 % versus 77.3 % (p = 0.9). The absolute increase was 26.0 versus 19.0 cm(2) postoperatively (p = 0.2). In contrast to these mean values and their distribution with no significant differences in Group A and B there was some correlation between development and percentage of ventricular surface in relation to the hemispheres prior to surgery: more than 40 % is a critical value, because most of the later retarded children belonged to this radiological subgroup and only half of the later normal patients. After surgery, there was a distinct correlation between developmental outcome and parenchymal surface and its absolute increase in cm(2): most of those who had a normal outcome had a parenchymal surface of more than 40 cm(2) in the third trimenon and an increase of 20 cm(2) and more within six months post surgery, whereas this was the case in only 40 - 50 % of the retarded patients.

CONCLUSIONS

In most young infants with hydrocephalus there is more brain mass than the ventricular enlargement suggests. The prognostic value of quantitative evaluation of neuroimaging should not be overestimated. Nevertheless, some prognostication in this age group is possible prior to surgery by measurement of ventricular area in relation to the hemispheres and after surgery by measurement of the parenchymal area and its increase in cm(2).

Comparative effects of angiotensin II and angiotensin III in rabbit adrenal and aortic tissues

The addition of angiotensin II (AII) and angiotensin III (AIII) to isolated tissue baths produced the same maximal contractile response of rabbit aortic strips. AIII was about 10 times less potent, the slope of its concentration-response curve was less steep and its rate of onset slower than that of AII. The responses of both AII and AIII were inhibited with equal potency by the surmountable AII antagonist Phe4, Tyr8-AII and its unsurmountable analog Sar1, Leu8-AII but the kinetic patterns of inhibition by both were less well defined with the agonist AIII than with AII. The addition of AIII to tissues which had exhibited a maximal response to AII did not increase the level of contraction, in contrast to the case when norepinephrine was added to tissues contracted by AII. Both AII and AIII displaced [125I]AII binding from rabbit adrenal membranes; AIII was 6 times less potent than AII but displayed competitive kinetics as an inhibitor of [125I]AII binding. In further studies two binding sites for [125I]AII were identified in adrenal membranes, having KD values of 2.0 +/- 0.2 and 19.6 +/- 2.3 nM, respectively. Each site was inhibited by both AII and AIII and the ratio of the apparent Ki values for the two hormones was not significantly different. The Hill coefficient for the high affinity site was, however, lower for AIII than AII. We interpret our data to suggest that AII and AIII act on the same receptors. AIII apparently binds less efficiently than does AII in both rabbit adrenal membranes and rabbit aortic strips.

Characterization of the hemodynamic activities of fenoldopam and its enantiomers in the dog

Fenoldopam (SK&F 82526) is a potent and selective dopamine DA-1 agonist with demonstrated renal vasodilator and antihypertensive activities in experimental animals and humans. Fenoldopam is a racemic mixture of two enantiomers, SK&F R-82526 and SK&F S-82526. The R-enantiomer is uniformly reported to be more potent than the racemate; in contrast, there is controversy regarding potency of the S-enantiomer. In these studies, the renal and systemic hemodynamic activities of fenoldopam and its enantiomers are characterized in anesthetized, phenoxybenzamine-treated dogs. The results show that the renal and systemic vasodilator activities of fenoldopam are properties of the R-enantiomer; the S-enantiomer is essentially inactive. The renal and systemic vasodilator properties of SK&F R-82526 are antagonized in a competitive fashion by the DA-1 antagonist, SK&F R-83566, but not the DA-2 antagonist, domperidone. Ganglionic blockade did not attenuate renal vasodilation associated with SK&F R-82526. Thus, the mechanism of SK&F R-82526-associated vasodilation, like that previously established for fenoldopam, is via stimulation of postganglionic DA-1 receptors.

Studies defining minimal receptor domains for angiotensin II

The purpose of this study was to define in a systematic experimental manner the minimal amino acid domain(s) present in the angiotensin II molecule that are required for binding to, as well as activation of, its receptor at physiological concentrations. Although removal of the C-terminal phenylalanine residue markedly reduced affinity for the rabbit adrenal cortical receptor, sequential additions of amino acids beginning with phenylalanine did not result in a molecule with significant receptor affinity until the hexapeptide stage was reached. Similar receptor affinities were obtained with the other two possible 6 amino acid fragments in the molecule. None of the possible pentapeptide fragments were active, as was also the case with representative 4, 3 and 2 amino acid sequences. Of the three hexapeptides, only the one containing phenylalanine as the C-terminal amino acid displayed agonist activity on the rabbit aortic strip. The other two behaved as competitive antagonists. These results indicate that 6 amino acids constitute the minimal receptor binding domain present in the angiotensin II molecule and that phenylalanine is crucial at the C-terminus for activating the receptor.

Studies on inhibition of angiotensin II receptors in rabbit adrenal and aorta

Angiotensin II (AII) labeled with 125I binds to rabbit adrenal cortical membranes over a concentration range from 0.5 to 20 nM at an apparent single site with a KD of 5 nM. This binding was inhibited in a surmountable fashion with respect to AII by the peptide analogs sarcosine1 (Sar1),Leu8AII and Phe4, Tyr8 AII when added to the incubation media concomitant with AII addition. With a 30-min preincubation, however, the former inhibitor displayed nonsurmountable kinetics whereas the profile of the latter was unaffected. In rabbit aortic strips with the same preincubation time, the Sar1Leu8AII analog was a nonsurmountable antagonist of the contractile effect of AII whereas the inhibition produced by Phe4,Tyr8AII was surmountable by increasing agonist (AII) concentrations. The inhibitory effect of the former was maintained after repeated washing of the tissue whereas that of the latter was readily reversible. Addition of Phe4,Tyr8AII to the bath 5 min before preincubation protected the tissue from the prolonged AII inhibition by Sar1,Leu8AII. These findings indicate different kinetic modes of AII inhibition by these two antagonists. Phe4,Tyr8AII behaves as a reversible, competitive inhibitor of AII binding, whereas Sar1,Leu8AII combines with the AII receptor in a slowly dissociable manner and is therefore not readily displaced by AII.