The science of hypoxia in the Northern Gulf of Mexico: a review

The Mississippi River is one of the world's 10 largest rivers, with average freshwater discharge into the northern Gulf of Mexico (GOM) of 380km(3) year(-1). In the northern GOM, anthropogenic nitrogen is primarily derived from agricultural fertilizer and delivered via the Mississippi River. The general consensus is that hypoxia in the northern Gulf of Mexico is caused primarily by algal production stimulated by excess nitrogen delivered from the Mississippi-Atchafalaya River Basin and seasonal vertical stratification of incoming stream flow and Gulf waters, which restricts replenishment of oxygen from the atmosphere. In this paper, we review the controversial aspects of the largely nutrient-centric view of the hypoxic region, and introduce the role of non-riverine organic matter inputs as other oxygen-consuming mechanisms. Similarly, we discuss non-nutrient physically-controlled impacts of freshwater stratification as an alternative mechanism for controlling in part, the seasonality of hypoxia. We then explore why hypoxia in this dynamic river-dominated margin (RiOMar) is not comparable to many of the other traditional estuarine systems (e.g., Chesapeake Bay, Baltic Sea, and Long Island Sound). The presence of mobile muds and the proximity of the Mississippi Canyon are discussed as possible reasons for the amelioration of hypoxia (e.g., healthy fisheries) in this region. The most recent prediction of hypoxia area for 2009, using the current nutrient-centric models, failed due to the limited scope of these simple models and the complexity of this system. Predictive models should not be the main driver for management decisions. We postulate that a better management plan for this region can only be reached through a more comprehensive understanding of this RiOMar system-not just more information on river fluxes (e.g., nutrients) and coastal hypoxia monitoring programs.

The eye gaze direction of an observed person can bias perception, memory, and attention in adolescents with and without autism spectrum disorder

The reported experiments aimed to investigate whether a person and his or her gaze direction presented in the context of a naturalistic scene cause perception, memory, and attention to be biased in typically developing adolescents and high-functioning adolescents with autism spectrum disorder (ASD). A novel computerized image manipulation program presented a series of photographic scenes, each containing a person. The program enabled participants to laterally maneuver the scenes behind a static window, the borders of which partially occluded the scenes. The gaze direction of the person in the scenes spontaneously cued attention of both groups in the direction of gaze, affecting judgments of preference (Experiment 1a) and causing memory biases (Experiment 1b). Experiment 2 showed that the gaze direction of a person cues visual search accurately to the exact location of gaze in both groups. These findings suggest that biases in preference, memory, and attention are caused by another person's gaze direction when viewed in a complex scene in adolescents with and without ASD.

Phase I study of PLX4032: Proof of concept for V600E BRAF mutation as a therapeutic target in human cancer

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Background: PLX4032 is an oral, selective inhibitor of the oncogenic V600E mutant BRAF kinase with preclinical activity. V600E BRAF is the most common kinase mutation in melanoma (60%), also found in colorectal carcinomas (10%), most anaplastic and papillary thyroid carcinomas, and low-grade serous ovarian carcinomas. Methods: Phase I, dose-escalation study designed to determine maximum tolerated dose (MTD), safety, pharmacokinetic (PK) / pharmacodynamic (PD), and efficacy (RECIST evaluation every 8 wks) of PLX4032 in sequential cohorts of 3 to 6 patients (pts). Plasma PK samples were collected on days 1, 8 and 15. Results: 54 pts have been enrolled: metastatic melanoma (n=49), thyroid (n=3), rectal (n=1), or ovarian carcinoma (n=1). 26 pts received a crystalline formulation (CF) continuously at doses from 100 mg BID to 1600 mg BID with associated exposures below target plasma levels. 28 pts received an optimized formulation with increased bioavailability, predicted to have 10-fold greater bioavailability, at doses from 160 mg BID to 1120 mg BID. AUC was dose-proportional and above target levels at 240 mg BID and higher. There was 1 DLT at 720 mg BID (G4 pancytopenia); treatment was restarted at 360 mg BID without myelosuppression. At 1120 mg BID, 3 of 5 pts had DLT (rash and fatigue). One pt had grade 3 increased ALT at 360 mg BID. 13 melanoma pts (77 %M1C) treated at doses of 240 mg BID or higher of the increased bioavailability formulation have a minimum follow-up of 8 weeks. 5 of the 7 BRAF V600E+ pts treated at ≥ 240 mg BID had tumor regression, up to 83%, with 1 confirmed partial response (PR) and 1 unconfirmed PR (too early); 2 of 4 pts with unknown V600E status had tumor regression, up to 50%, with 1 confirmed PR; 2 BRAF wild-type pts had progressive disease. All 7 pts with tumor regression remain progression-free, ranging from 4 to 14 months. 3 thyroid cancer pts with V600E mutations have tumor regression (range 9–16%) and are progression-free (4–7 months). Conclusions: Dose escalation of PLX4032 reached DLTs at 1120 mg BID. 720 mg BID is the current MTD, but 960 mg BID may be explored. PLX4032 exhibits antitumor activity in V600E BRAF mutant tumors. These observations confirm that V600E BRAF is a valid therapeutic target in human cancer.

[Table: see text]

Characteristics of first relapse in stage III melanoma patients with no evidence of disease (NED): Guidelines for follow-up

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Background: Follow up (F/U) of patients (pts) with AJCC stage III melanoma but with NED is currently empiric with respect to frequency of clinical exams, F/U duration, and diagnostic tests. Data-based F/U guidelines are needed. Methods: Clinical records of 429 pts with stage III NED pts seen at MSKCC between 1998 and 2002 and who ultimately relapsed were reviewed retrospectively to evaluate: site and date of 1st relapse, interval between the stage III NED and 1st relapse; how the 1st relapse was detected, date of death or last F/U. We also determined the overall 5 yr relapse-free survival (RFS) of all stage III pts seen at MSKCC during this period. Results: The overall 5 yr RFS for stage IIIA, B, and C patients at MSKCC was: 52%, 29%, and 15%, respectively. Among the relapsing pts, 280 had adequate F/U to be evaluable for all parameters (35 stage IIIA, 155 stage IIIB, 90 stage IIIC). The site of 1st relapse was local/in-transit (28%), regional nodal (20%), or systemic sites (52%). The most common sites of 1st systemic relapse were lung, liver, brain. There were significant differences among substages. First relapses were detected by the pt or family, MD, or by screening radiological tests in 52%, 19%, and 29% of cases, respectively. Multivariate analysis revealed better overall survival (OS) was not associated with time to relapse but was associated with younger age and if 1st relapse was: a) local/in-transit or nodal, b) asymptomatic, or c) resectable. By noting when the risk for 1st local/intransit, nodal, or systemic (lung, liver, brain) relapse became sufficiently low (<5%) for each substage, we generated tentative F/U guidelines ( Table ). Conclusions: Our data suggest that F/U strategies for stage III should be adapted by substage and indicate time ranges beyond which more prolonged F/U would be unlikely to benefit pts. Whether frequent F/U within these time ranges can increase the chances of complete surgical resection or improve OS is not known.

[Table: see text]

No significant financial relationships to disclose.

High-resolution imaging of an ancient Egyptian mummified head: new insights into the mummification process

BACKGROUND AND PURPOSE

Systematic facial mutilations during mummification have never been described before. The purpose of this work was to study a wrapped mummified head using high-resolution CT scanning.

MATERIALS AND METHODS

An isolated mummified head from the Egyptian Middle Kingdom was scanned at 200 mum isotropic resolution. A prototype flat panel CT scanner was used to generate 800 nonoverlapping CT sections at 120 kV and 50 mA. This dataset was analyzed to discern various surgical alterations during mummification.

RESULTS

There were large defects in the cribriform plate and the posterior fossa. Systematic mutilations of the facial bones and mandible, involving the anterior and inferior walls of the maxillary sinuses, the floor of both orbits, and the zygomatic arches with contiguous segments of the zygomas, were demonstrated. The coronoid processes of both mandibles had been sharply excised and the articular tubercles of the temporomandibular joints fractured.

CONCLUSION

Defects in the ethmoid and the posterior skull base are consistent with previous descriptions of excerebration. Mutilations of the facial skeleton and jaw, which are unrelated to the process of excerebration, have never been described previously. It is noteworthy that the osteotomies selectively include the insertions of the muscles of mastication. These mutilations apparently were designed for mobilization of lower jaw. The "Opening of the Mouth" ceremony, described in the ancient texts, would be difficult to perform in the presence of rigor mortis; it is probable that the observed osteotomies were performed to facilitate this ceremony. Our research suggests that by the Middle Kingdom, Egyptian embalmers had developed highly sophisticated surgical techniques that have not been appreciated previously.

Proton stereotactic radiosurgery in management of persistent acromegaly

OBJECTIVE

To evaluate the efficacy and safety of proton stereotactic radiosurgery (PSRS) for acromegaly that is refractory to surgical treatment and medication.

METHODS

From 1992 to 2003, 22 patients were treated at our institution for persistent acromegaly with use of PSRS. All patients had undergone at least one transsphenoidal surgical procedure without biochemical cure. The median treatment dose delivered during PSRS was 20 (range, 15 to 24) cobalt gray equivalents.

RESULTS

Follow-up was available for all patients at a median of 6.3 (range, 2.5 to 14.2) years after PSRS. A response to PSRS was observed in 21 of 22 patients (95%). A complete response (CR), defined as sustained (> or =3 months) normalization of insulinlike growth factor-I without medical suppression, was attained in 13 patients (59%). Among patients with CR, the median time to CR was 42 (range, 6 to 62) months. No visual complications, seizures, clinical evidence of brain injury, or secondary tumors were noted on regular magnetic resonance imaging scans. One patient had complete pituitary dysfunction before PSRS and was therefore excluded from evaluation for failure. Of the other 21 patients, 8 (38%) had new pituitary deficits.

CONCLUSION

These results demonstrate that PSRS is effective for persistent acromegaly, with 59% of patients attaining normal insulinlike growth factor-I levels without use of any medication after a median of 6.3 years. Our findings indicate that radiosurgery results in an expeditious biochemical response with low morbidity.

Proton radiosurgery in neurosurgery

OBJECT

Photon energy deposition from gamma or photon sources follows the law of exponential decay. Consequently, energy is deposited over the entire path of the radiation beam, resulting in dose distribution before and after the target is reached. In contrast, the physical properties of protons are such that energy deposition occurs with no exit dose beyond the target volume. Therefore, relative to photons, proton beams represent a superior platform for the administration of radiosurgery.

METHODS

In this review, the authors will discuss the fundamental principles underlying photon- and proton-based stereotactic radiosurgery (SRS). The clinical efficacy of proton-based SRS in the treatment of arteriovenous malformations, vestibular schwannomas, and pituitary adenomas is reviewed.

RESULTS

Direct comparisons of clinical results attained using photon- and proton-based SRS are confounded by a bias toward reserving proton beams for the treatment of larger and more complex lesions. Despite this bias, the clinical outcomes for proton-based SRS have been excellent and have been at least comparable to those for photon-based treatments.

CONCLUSIONS

The physical properties of proton radiation offer superior conformality in dose distribution relative to photon irradiation. This advantage becomes more apparent as the lesion size increases and will probably be magnified with the development of intensity-modulated proton techniques.

Proton stereotactic radiotherapy for persistent adrenocorticotropin-producing adenomas

CONTEXT

Radiation therapy is a potentially curative treatment for corticotroph adenomas refractory to surgery. Protons have an advantage over photons (x-rays) by depositing energy at the target with no exit dose, providing a lower dose to adjacent normal tissues. Until recently, proton stereotactic radiotherapy (PSR) was available at only two U.S. centers; use will increase as proton facilities are under development.

OBJECTIVE

Our objective was to evaluate the efficacy and safety of PSR for persistent Cushing's disease (CD) and Nelson's syndrome (NS).

DESIGN

This was a retrospective review of 38 patients (33 with CD and five with NS) treated between 1992 and 2005.

PARTICIPANTS

All patients had transsphenoidal surgery without biochemical cure. Four had previous irradiation with photons. The patients with NS underwent bilateral adrenalectomy 29-228 months (median 40) before PSR.

INTERVENTION

Single-fraction PSR was delivered at a median dose of 20 Cobalt Gray Equivalents (range 15-20) on 1 treatment day.

MAIN OUTCOME MEASURES

Complete response (CR) was defined as sustained (> or =3 months) normalization of urinary free cortisol off medical therapy. CR in NS was based on normalization of plasma corticotropin.

RESULTS

At a median follow-up of 62 months (range 20-136), CR was achieved in five patients (100%) with NS and 17 (52%) patients with CD. Among all patients with CR, median time to CR was 18 months (range 5-49). No secondary tumors were noted on follow-up magnetic resonance imaging scans, and there was no clinical evidence of optic nerve damage, seizure, or brain injury. There were 17 patients (52%) who developed new pituitary deficits.

CONCLUSIONS

PSR is effective for patients with persistent corticotroph adenomas with low morbidity after a median follow-up of 62 months; longer follow-up is warranted for late radiation-related sequelae.

A modified Delphi exercise to determine the extent of consensus with OMERACT outcome domains for studies of acute and chronic gout

OBJECTIVES

To reach consensus with recommendations made by an OMERACT Special Interest Group (SIG).

METHODS

Rheumatologists and industry representatives interested in gout rated and clarified, in three iterations, the importance of domains proposed by the OMERACT SIG for use in acute and chronic gout intervention studies. Consensus was defined as a value of less than 1 of the UCLA/RAND disagreement index.

RESULTS

There were 33 respondents (61% response rate); all agreed the initial items were necessary, except "total body urate pool". Additional domains were suggested and clarification sought for defining "joint inflammation" and "musculoskeletal function". Items that demonstrated no clear decision were re-rated in the final iteration. There were six highly rated items (rating 1-2) with four slightly lower rating items (rating 3) for acute gout; and 11 highly rated items with eight slightly lower ratings for chronic gout.

CONCLUSIONS

Consensus is that the following domains be considered mandatory for acute gout studies: pain, joint swelling, joint tenderness, patient global, physician global, functional disability; and for chronic gout studies: serum urate, gout flares, tophus regression, health-related quality of life, functional disability, pain, patient global, physician global, work disability and joint inflammation. Several additional domains were considered discretionary.

Phase II trial of extended-dosing temozolomide in patients with melanoma

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Background: To test the hypothesis that the ∼30% response rate we observed in metastatic melanoma (mel) patients (pts) treated with temozolomide (TMZ) using an extended dosing schedule with either thalidomide or interferon was largely due to TMZ alone, we conducted a phase II trial of TMZ alone. We also hypothesized that mel expression of methylguanine methyltransferase (MGMT) would correlate with drug resistance. Methods: Stage IV mel pts without brain metastases or prior chemotherapy were stratified into two cohorts based on whether or not they had stage M1c disease. Each cycle consisted of TMZ 75 mg/m2/day for 6 weeks followed by 2 weeks with no treatment. Treatment cycles were repeated as long as pts did not progress. The primary endpoint was the proportion of complete or partial responses by RECIST criteria. The trial was powered to exclude the null hypothesis that the response rate in each cohort was <30%. MGMT promoter methylation status was assessed by methylation-specific pyrosequencing. In pts with insufficient tumor material for pyrosequencing, MGMT expression was measured by immunohistochemistry using the monoclonal antibody MT3.1. Results: To date we have accrued 48 pts, 23 in the M1c cohort. 7 pts are still receiving treatment and are not yet evaluable for response. There have been 4 partial responses observed, 2 in each cohort. The median number of cycles was 2 (range 1–6). 9/41 pts (22%) were stable for =6 months and received =3 cycles. 56% of pts developed CD4+ lymphopenia (<500/μl) during treatment; 37% of pts developed CD4+ lymphopenia <200/μl and received PCP prophylaxis. Opportunistic infections were not observed. Conclusions: The overall response rate is 9.8% (95% CI 0.8%-19%). The estimated median survival is 11 months for the stage III/M1a/b cohort and 9.7 months for the M1c cohort. To date, the response proportion to TMZ alone appears to be <30%. There would need to be 3 more responses in a cohort to reject the null hypothesis for that cohort. MGMT analyses are ongoing and will be used to determine if promoter methylation status correlates with objective response rate or time to progression. The study was supported by Schering-Plough.

No significant financial relationships to disclose.

Audit of pneumocystis pneumonia in patients seen by the Christchurch Hospital rheumatology service over a 5-year period

AIM

The aim of the study was to review all cases of Pneumocystis carinii pneumonia (PCP) in patients seen by the Christchurch Hospital Rheumatology service over a 5-year period and to determine the annual incidence of PCP.

METHODS

The Canterbury Health Laboratory database was searched for rheumatology patients testing positive for PCP from 31 December 2000 to 31 December 2005. The rheumatology database was then searched to identify patients receiving the same immunosuppressant medication as those who developed PCP to determine the annual incidence of PCP in this group.

RESULTS

Four rheumatology patients were diagnosed with PCP during the 5-year period. Two were receiving oral methotrexate (MTX) for rheumatoid arthritis and two were receiving cyclophosphamide (CYC), one each for Wegener's granulomatosis and dermatomyositis. None of the four cases was receiving PCP chemoprophylaxis. Five hundred and forty-seven patients commenced MTX over the same 5-year period and 47 commenced CYC. Only 14 of 47 (29.7%) CYC-treated patients received PCP prophylaxis. The annual incidence of PCP was 0.17% (95% confidence interval (CI) 0.02-0.63) and 5.33% (95%CI 0.65-19.24) in patients prescribed MTX and CYC, respectively. For the 33 patients receiving CYC without concomitant PCP prophylaxis the annual incidence was 9.50% (95%CI 1.15-34.33).

CONCLUSION

In our study the annual incidence of PCP in patients taking MTX was low and would not support the use of routine PCP chemoprophylaxis. In patients receiving CYC without concomitant PCP chemoprophylaxis the annual incidence of PCP was higher although the number of cases was small. Given the high morbidity and mortality in this group, PCP chemoprophylaxis should be considered.

Voice outcomes following transoral laser microsurgery for early glottic squamous cell carcinoma

INTRODUCTION

Early glottic cancer may be treated with primary radiotherapy or transoral laser microsurgery with comparable survival. The choice of therapy therefore depends on patient preference after discussion of risks, benefits and alternatives.

MATERIALS AND METHODS

All previously untreated patients undergoing transoral laser microsurgery for T1 or T2 glottic cancer at St Vincent's Hospital between July 1997 and December 2004 had their staging and demographics recorded. Surgery was categorised according to the European Laryngological Society. A voice recording was made pre-operatively then at 12 weeks post-operatively and scored by two independent speech therapists on the Oates Russell Voice Profile - a scale of zero (normal) to five (severe dysphonia). Follow up was for a minimum of two years.

RESULTS AND ANALYSIS

Fifty-three patients with a mean age of 56 were included. The observed survival was T1 89.4 per cent and T2 85.3 per cent after a mean follow up of 47 months. Nineteen patients staged T1 underwent cordectomy. A second procedure was required in 22.2 per cent, however, none required a laryngectomy. Thirty-four patients staged T2 underwent hemilaryngectomy. A second procedure was required in 41.2 per cent including 8.8 per cent requiring salvage laryngectomy. One patient died with unresectable nodal disease. The mean Oates Russell Voice Profile for T1 disease was 2.37 and for T2 2.68 (range 1 to 4) indicating a mild (2) to moderate (3) degree of voice impairment.

CONCLUSIONS

Survival outcomes following transoral laser microsurgery are comparable to treatment with radiotherapy. Voice impairment is usually mild to moderate following transoral laser microsurgery for early glottic cancer but overall may be greater than in radiotherapy patients. The repeatability of transoral laser microsurgery may result in a lower laryngectomy rate compared with published series using radiotherapy.

Genomic DNA pooling for whole-genome association scans in complex disease: empirical demonstration of efficacy in rheumatoid arthritis

A pragmatic approach that balances the benefit of a whole-genome association (WGA) experiment against the cost of individual genotyping is to use pooled genomic DNA samples. We aimed to determine the feasibility of this approach in a WGA scan in rheumatoid arthritis (RA) using the validated human leucocyte antigen (HLA) and PTPN22 associations as test loci. A total of 203 269 single-nucleotide polymorphisms (SNPs) on the Affymetrix 100K GeneChip and Illumina Infinium microarrays were examined. A new approach to the estimation of allele frequencies from Affymetrix hybridization intensities was developed involving weighting for quality signals from the probe quartets. SNPs were ranked by z-scores, combined from United Kingdom and New Zealand case-control cohorts. Within a 1.7 Mb HLA region, 33 of the 257 SNPs and at PTPN22, 21 of the 45 SNPs, were ranked within the top 100 associated SNPs genome wide. Within PTPN22, individual genotyping of SNP rs1343125 within MAGI3 confirmed association and provided some evidence for association independent of the PTPN22 620W variant (P=0.03). Our results emphasize the feasibility of using genomic DNA pooling for the detection of association with complex disease susceptibility alleles. The results also underscore the importance of the HLA and PTPN22 loci in RA aetiology.