Screening macroalgae for mitigation of enteric methane in vitro

This study investigated the effects of 67 species of macroalgae on methanogenesis and rumen fermentation in vitro. Specimens were analyzed for their effect on ruminal fermentation and microbial community profiles. Incubations were carried out in an automated gas production system for 24-h and macroalgae were tested at 2% (feed dry matter basis) inclusion rate. Methane yield was decreased 99% by Asparagopsis taxiformis (AT) when compared with the control. Colpomenia peregrina also decreased methane yield 14% compared with control; no other species influenced methane yield. Total gas production was decreased 14 and 10% by AT and Sargassum horneri compared with control, respectively. Total volatile fatty acid (VFA) concentration was decreased between 5 and 8% by 3 macroalgae, whereas AT reduced it by 10%. Molar proportion of acetate was decreased 9% by AT, along with an increase in propionate by 14%. Asparagopsis taxiformis also increased butyrate and valerate molar proportions by 7 and 24%, respectively, whereas 3 macroalgae species decreased molar proportion of butyrate 3 to 5%. Vertebrata lanosa increased ammonia concentration, whereas 3 other species decreased it. Inclusion of AT decreased relative abundance of Prevotella, Bacteroidales, Firmicutes and Methanobacteriaceae, whereas Clostridium, Anaerovibrio and Methanobrevibacter were increased. Specific gene activities for Methanosphaera stadtmane and Methanobrevibacter ruminantium were decreased by AT inclusion. In this in vitro study, Asparagopsis taxiformis was most effective in decreasing methane concentration and yield, but also decreased total gas production and VFA concentration which indicates overall inhibition of ruminal fermentation. No other macroalgae were identified as potential mitigants of enteric methane.

Deformation of metallic liquid drop by electric field for contacts in molecular–organic electronics

We study and use the behaviour of a metallic liquid drop in the presence of an external electric field (EF). The droplet profile is governed by the stabilizing surface energy and the destabilizing electrostatic energy, with a critical voltage beyond which the droplet becomes unstable. We explore the EF-induced behaviour of low melting temperature alloy in the liquid state and observe that the droplet modifications in the linear response regime can be retained upon cooling the drop to the solid state. We demonstrate that this procedure can be used as an electrode with precise dimensions for applications in molecular and polymer electronics.

A phase I study of tirapazamine in combination with radiation and weekly cisplatin in patients with locally advanced cervical cancer

5543

Background and Purpose: Hypoxia is an adverse prognostic factor in locoregionally advanced cervical cancer treated with radiation. GOG are currently studying the hypoxic cytotoxin, tirapazamine (TPZ) in combination with biweekly intermediate dose cisplatin (CIS) and radiation in a large phase III trial. The aim of this phase I study was to develop a better tolerated regimen that added TPZ to the standard regimen of radiation and weekly low dose CIS. Methods: Eligible patients had previously untreated carcinoma of the cervix, Stages IB2 - IVA. The starting schedule was radiotherapy (45 to 50.4 Gy external beam radiation followed by brachytherapy), with concomitant weekly CIS 40 mg/m2 weeks 1–6 and weekly TPZ 290 mg/m2 (prior to CIS) in weeks 1–5. Results: Between 3/05 and 7/06 eleven patients were enrolled, median age (range) 52 (31–65), squamous cell carcinoma 10, adenocarcinoma 1, 1B2–5, IIA-1, IIB-3, IIIB- 1, IVA-1. The first 2 patients on dose level 1 experienced a dose limiting toxicity (DLT), one grade 3 ALT (SGPT) elevation and grade 4 pulmonary embolism and one grade 3 ototoxicity. Doses were decreased to dose level -1 CIS 30 mg/m2 and TPZ 260 mg/m2. Three patients were treated without any DLTs. Six patients were then treated on dose level -1a, CIS 35 mg/m2 and TPZ 260 mg/m2, with 2 DLTs: grade 3 neutropenia with dose omission and grade 4 pulmonary embolism with major hemodynamic compromise. The sixth patient on dose level -1a withdrew from the trial in week 2 after being advised about the DLTs observed on this dose level. 3 additional patients will be accrued on dose level -1 to confirm safety of this dose level. One patient has relapsed in pelvic nodes, all other patients remain disease-free with a median followup of 10 months (range 5 - 21) Conclusions: The combination of weekly TPZ and CIS with radiation for locally advanced cervical cancer was associated with more toxicity than anticipated with the recommended dose level being TPZ 260 mg/m2, CIS 30 mg/m2.

No significant financial relationships to disclose.

Significance of tumor volume and corpus uteri invasion in cervical cancer patients treated by radiotherapy

The purpose of this study was to show that in advanced cervical cancer patients treated with curative intent, tumor volume and uterine involvement have independent prognostic value. Eligible patients were those seen at the Peter MacCallum Cancer Centre between December 1995 and June 2001, newly diagnosed with a histologic diagnosis of squamous cell carcinoma or adenocarcinoma of the cervix, FIGO-staged IB-IVA, and having undergone magnetic resonance imaging (MRI) and treated with curative intent. Potential prognostic factors considered were FIGO stage, clinical tumor diameter, histology, age, tumor volume, and corpus invasion status. MRI was used to determine the tumor volume and whether there was invasion of tumor into the corpus uteri. One hundred and seventy-nine patients were eligible for this study. The cut-off date for follow-up was October 2003, one patient was lost to follow-up, and the mean potential follow-up time was 4.5 years (range 0.2-7.7 years). There were 60 (34%), 78 (44%), 34 (19%), and 7 (4%) patients in FIGO stages IB, II, III, and IVA, respectively. The tumors of 107 (60%) patients exhibited corpus invasion. The median tumor volume was 33 mL (range 0.1-200 mL). The four factors, FIGO stage, clinical tumor diameter, corpus invasion, and tumor volume, were all strongly positively correlated (P < 0.001 in each case). The 5-year overall survival (OS) rate for all patients was 55% (standard error = 4%). Of the six factors examined, FIGO stage (P= 0.006), clinical tumor diameter (P= 0.013), corpus invasion (P < 0.001), and tumor volume (P < 0.001) were statistically significantly related to OS duration in unifactor analyses. However, only corpus invasion (P= 0.013) and tumor volume (P= 0.004) were significantly and independently associated with OS in multifactor analyses. In particular, after adjusting for corpus involvement and tumor volume, there was no evidence for any relationship between OS and either FIGO stage (P= 0.49) or clinical tumor diameter (P= 0.58). The results from the analysis of failure-free survival were very similar. We conclude that in patients with advanced cervical cancer, tumor volume and corpus invasion provide important prognostic information over and above that provided by FIGO stage, clinical tumor diameter, histology, and age.

Arguments for a magnetic resonance imaging-assisted FIGO staging system for cervical cancer

FIGO staging of cervical cancer is based on anatomic compartmental spread of cervical cancer. This was necessary in the evaluation of surgical resectability in each patient. Even if the surgical resection was not deemed satisfactory, surgical findings and subsequent accurate anatomic pathology findings could be used to prescribe tailored adjuvant therapies. Recently, the management of cervical cancer has been influenced by the evidence from several surgical-pathologic studies and phase II and III combined modality treatment trials. However, the patient selection criteria used in these clinical studies were almost always refined by modern medical imaging and surgical techniques not prescribed in the FIGO staging system. The results obtained from these studies would not correlate with those from the patient population similarly treated but selected strictly along the FIGO staging criteria. This selective, heterogenous, and arbitrary refinement of FIGO staging has certainly given insight into cervical cancer biology but in the process has rendered the current FIGO staging of this disease quite inadequate. Prior knowledge of these factors through modern imaging in these patients could be used in staging and selecting the optimum treatment modality while minimizing the treatment-related morbidity. A magnetic resonance imaging-assisted FIGO staging system for cervical cancer as proposed here could be used for selecting patients appropriately for a given treatment package.

Managing advanced-stage cervical cancer

The current staging methods and the definition of advanced cervical cancer are discussed. The clinical International Federation of Gynaecology and Obstetrics (FIGO) staging system has been found to be inaccurate and this limits treatment planning. More accurate management could be based on surgicopathological features of the tumour. However, the latest imaging techniques have the potential to give us this information in a non-invasive way. To deliver optimal treatment in advanced cervical cancer, we need to optimize the way we categorize the prognostic groups. Accurately delineating the extent of the disease will potentially minimize treatment morbidity and improve survival. The techniques of chemoradiation are also discussed in detail.

Arguments for a magnetic resonance imaging–assisted FIGO staging system for cervical cancer

FIGO staging of cervical cancer is based on anatomic compartmental spread of cervical cancer. This was necessary in the evaluation of surgical resectability in each patient. Even if the surgical resection was not deemed satisfactory, surgical findings and subsequent accurate anatomic pathology findings could be used to prescribe tailored adjuvant therapies. Recently, the management of cervical cancer has been influenced by the evidence from several surgical-pathologic studies and phase II and III combined modality treatment trials. However, the patient selection criteria used in these clinical studies were almost always refined by modern medical imaging and surgical techniques not prescribed in the FIGO staging system. The results obtained from these studies would not correlate with those from the patient population similarly treated but selected strictly along the FIGO staging criteria. This selective, heterogenous, and arbitrary refinement of FIGO staging has certainly given insight into cervical cancer biology but in the process has rendered the current FIGO staging of this disease quite inadequate. Prior knowledge of these factors through modern imaging in these patients could be used in staging and selecting the optimum treatment modality while minimizing the treatment-related morbidity. A magnetic resonance imaging-assisted FIGO staging system for cervical cancer as proposed here could be used for selecting patients appropriately for a given treatment package

Chemotherapy Delays Progression of Motor Neuron Disease in the SOD1 G93A Transgenic Mouse

BACKGROUND

A significant proliferation of glial cells occurs in the spinal cord and brainstem of SOD1 G93A transgenic mice with familial amyotrophic lateral sclerosis (ALS). Since activated glia may contribute to motor neuron degeneration, we tested whether inhibition of gliosis using low-dose chemotherapy is beneficial in this mouse model.

METHODS

Mice were administered fortnightly intraperitoneal injections of 0.1 mg/kg vincristine (VIN) or saline commencing at postnatal day 68 before disease onset. Mice were sacrificed at end-stage disease, and spinal cords were examined for histology.

RESULTS

Survival of VIN-treated mice was significantly increased at 132.0 +/- 4.1 days compared to control animals at 117.8 +/- 2.1 days (p < 0.05). Furthermore, analysis of microglia and astrocyte populations suggests a reduction in the former following VIN therapy.

CONCLUSION

This study suggests that chemotherapy may offer an alternative therapy or co-therapy for ALS.

Imaging modulated reflections from a semi-crystalline state of profilin:actin crystals

Modulated protein crystals remainterra incognitafor most crystallographers. While small-molecule crystallographers have successfully wrestled with and conquered this type of structure determination, to date no modulated macromolecular structures have been reported. Profilin:β-actin in a modulated semi-crystalline state presents a challenge of sufficient biological significance to motivate the development of methods for the accurate collection of data on the complex diffraction pattern and, ultimately, the solution of its structure. In the present work, fine φ-sliced data collection was used to resolve the closely spaced satellite reflections from these polymorphic crystals. Image-processing methods were used to visualize these data for comparison with the original precession data. These preliminary data demonstrate the feasibility of using fine φ-slicing to collect accurately the intensities and positions of the main and satellite reflections from these modulated protein crystals.

Relation between FIGO stage, primary tumor volume, and presence of lymph node metastases in cervical cancer patients referred for radiotherapy

The aims of this study were to determine, firstly, the relationship between FIGO stage and various tumor parameters determined by magnetic resonance imaging (MRI), and, secondly, whether any of these parameters were predictors of lymph node metastases as determined by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) in cervical cancer patients referred for radiotherapy. In 70 consecutive patients, both PET and MRI visualized all primary tumors except for one previously removed by cone biopsy. While clinical diameter and MRI-derived diameter showed a significant relationship between these two measurements (r = 0.70; P < 0.001) there was a large variability in MRI diameter for each FIGO stage and wide overlap. The average volume of primary cervical tumor on MRI was 60 cc (5-256). In FIGO stages, I, II, III and IV, uterine body involvement was present in 58%, 73%, 88%, and 100% of 19, 30, 16, and 5 patients, respectively (Ptrend= 0.015). Node positivity on FDG PET was present in 11% of patients without uterine body extension, but increased to 75% in those with uterine involvement. Average tumor volume in node-negative patients was 49 cc (5-186). Average tumor volume in node-positive patients was 69 cc (8-256). There was a significant association between nodal involvement and both FIGO stage (P = 0.018) and uterine body involvement (P < 0.001), but tumor volume and longitudinal MRI diameter were not statistically significant in unifactor predictors of nodal involvement. In multivariate analysis only uterine body extension, however, was independently related to the risk of nodal involvement. In conclusion, MRI provides noninvasive tumor size evaluation and can also demonstrate invasion of the uterine body that appears to be associated with an increased risk of nodal metastasis. This may provide clinically important prognostic information not available from current FIGO staging.

Relation between FIGO stage, primary tumor volume, and presence of lymph node metastases in cervical cancer patients referred for radiotherapy

The aims of this study were to determine, firstly, the relationship between FIGO stage and various tumor parameters determined by magnetic resonance imaging (MRI), and, secondly, whether any of these parameters were predictors of lymph node metastases as determined by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) in cervical cancer patients referred for radiotherapy. In 70 consecutive patients, both PET and MRI visualized all primary tumors except for one previously removed by cone biopsy. While clinical diameter and MRI-derived diameter showed a significant relationship between these two measurements (r = 0.70; P < 0.001) there was a large variability in MRI diameter for each FIGO stage and wide overlap. The average volume of primary cervical tumor on MRI was 60 cc (5–256). In FIGO stages, I, II, III and IV, uterine body involvement was present in 58%, 73%, 88%, and 100% of 19, 30, 16, and 5 patients, respectively (Ptrend = 0.015). Node positivity on FDG PET was present in 11% of patients without uterine body extension, but increased to 75% in those with uterine involvement. Average tumor volume in node-negative patients was 49 cc (5–186). Average tumor volume in node-positive patients was 69 cc (8–256). There was a significant association between nodal involvement and both FIGO stage (P = 0.018) and uterine body involvement (P < 0.001), but tumor volume and longitudinal MRI diameter were not statistically significant in unifactor predictors of nodal involvement. In multivariate analysis only uterine body extension, however, was independently related to the risk of nodal involvement. In conclusion, MRI provides noninvasive tumor size evaluation and can also demonstrate invasion of the uterine body that appears to be associated with an increased risk of nodal metastasis. This may provide clinically important prognostic information not available from current FIGO staging.

A comparison of MRI and PET scanning in surgically staged loco-regionally advanced cervical cancer: potential impact on treatment

The aim of this study was to assess whether positron emission tomography (PET) or magnetic resonance imaging (MRI) could obviate the need for surgical staging in patients with locally advanced cervical carcinoma being planned for radiotherapy (RT). Imaging findings were compared to surgical staging in 27 patients including three with recent resection of the primary tumor. Both PET and MRI visualized all 24 residual cervical tumors. Primary tumor volume, as measured by MRI scan, ranged from 1.25 cc to 140 cc. In 24 patients evaluable for pelvic nodal status, PET had sensitivity, specificity, and positive and negative predictive values of 83%, 92%, 91% and 85%, respectively, with 88% accuracy. MRI detected only six in 12 (50%) patients with confirmed pelvic nodal disease, all of which were also seen by CT and PET, with an overall accuracy of 75%. PET detected only four in seven (57%) cases with confirmed para-aortic (PA) involvement. All histologically confirmed sites not visualized on PET were <1 cm. Without surgical staging, six in 10 (60%) patients with histologically proven pelvic nodal disease would not have received pelvic boost if guided by MRI alone, compared to two in 10 (20%) patients guided by PET alone or in combination with MRI. All four patients with positive PA on PET were confirmed on histology or clinical follow-up, including one case that proved to be a false negative one on surgery. However, in three cases, PET would have yielded an inadequate radiation volume. In conclusion, the positive predictive value of PET in the pelvis and para-aortic region appears sufficient to obviate lymph nodal sampling, but sampling is still required to exclude small-volume disease cranial to sites of abnormality on PET. MRI has insufficient accuracy for nodal staging to impact management.

A comparison of MRI and PET scanning in surgically staged loco-regionally advanced cervical cancer: Potential impact on treatment

Abstract.

Narayan K, Hicks RJ, Jobling T, Bernshaw D, McKenzie AF. A comparison of MRI and PET scanning in surgically staged loco-regionally advanced cervical cancer: Potential impact on treatment.

The aim of this study was to assess whether positron emission tomography (PET) or magnetic resonance imaging (MRI) could obviate the need for surgical staging in patients with locally advanced cervical carcinoma being planned for radiotherapy (RT). Imaging findings were compared to surgical staging in 27 patients including three with recent resection of the primary tumor. Both PET and MRI visualized all 24 residual cervical tumors. Primary tumor volume, as measured by MRI scan, ranged from 1.25 cc to 140 cc. In 24 patients evaluable for pelvic nodal status, PET had sensitivity, specificity, and positive and negative predictive values of 83%, 92%, 91% and 85%, respectively, with 88% accuracy. MRI detected only six in 12 (50%) patients with confirmed pelvic nodal disease, all of which were also seen by CT and PET, with an overall accuracy of 75%. PET detected only four in seven (57%) cases with confirmed para-aortic (PA) involvement. All histologically confirmed sites not visualized on PET were <1 cm. Without surgical staging, six in 10 (60%) patients with histologically proven pelvic nodal disease would not have received pelvic boost if guided by MRI alone, compared to two in 10 (20%) patients guided by PET alone or in combination with MRI. All four patients with positive PA on PET were confirmed on histology or clinical follow-up, including one case that proved to be a false negative one on surgery . However, in three cases, PET would have yielded an inadequate radiation volume. In conclusion, the positive predictive value of PET in the pelvis and para-aortic region appears sufficient to obviate lymph nodal sampling, but sampling is still required to exclude small-volume disease cranial to sites of abnormality on PET. MRI has insufficient accuracy for nodal staging to impact management.

Australian high-dose-rate brachytherapy protocols for gynaecological malignancy

There is no consensus over the optimal dose fractionation schedules for high-dose-rate (HDR) brachytherapy used for gynaecological malignancy. In Australian public hospital departments of radiation oncology, HDR brachytherapy for gynaecological cancer is being more commonly used. A survey of public departments that are using this technology, or that plan to introduce this technology, was performed. Their current protocols are presented. In general, protocols are similar biologically; however, the practical aspects such as the number of fractions given do vary and may reflect resource restrictions or, alternatively, differences in interpretations of the literature and of the best protocols by clinicians.

Referral patterns for gynaecological radiotherapy in Victoria

A retrospective chart review was undertaken on all patients in Victoria who were referred for radiotherapy for a gynaecological cancer from February 1997 to January, 1998. Three hundred and ten patients were identified which represents less than one-third of all gynaecological cancers diagnosed in Victoria each year. Ninety-two of the 310 patients (30%) referred for radiotherapy were managed without the prior involvement of a certified gynaecological oncologist. The 310 patients included 95 patients with cervical cancer, 33 patients with ovarian cancer and 142 patients with endometrial cancer. The initial management strategies employed for patients with the major gynaecological cancers varied depending on the source of referral. This difference was most marked in endometrial cancer due mainly to differing indications for full surgical staging and subsequent referral for radiotherapy both between types of specialists and also between gynaecological oncology units. The development of evidence based guidelines in the major gynaecological cancers should lead to a more uniform approach to the care of women with gynaecological malignancies.

Planned neck dissection as an adjunct to the management of patients with advanced neck disease treated with definitive radiotherapy: for some or for all?

BACKGROUND

Management of patients with head and neck carcinoma and advanced nodal disease is controversial. The purpose of this analysis was to evaluate the efficacy and toxicity of definitive radiotherapy followed by planned neck dissection in patients with bulky neck disease.

MATERIALS AND METHODS

The records of 52 patients who were treated between 1989 and 1995 at the Peter MacCallum Cancer Institute with a planned neck dissection after radical radiotherapy were reviewed. All had advanced neck disease with one or more nodes >/=3 cm in maximum diameter, 94% being staged N2-3. The most common primary site was the oropharynx (56%). Sixty percent of patients had either T2 or T3 primaries and all were AJCC stage IV. Treatment consisted of high-dose radiotherapy to the primary and involved neck sites using various fractionation protocols followed by radical or modified radical neck dissection after confirmation of a complete response at the primary site. The median follow-up for living patients was 58 months (range 32-97).

RESULTS

There were nine regional failures, of which three were outside the dissected neck, yielding a 5-year actuarial overall neck control rate of 83% and an in-field control rate of 88%. In-field control rates by neck stage were N1 3/3; N2 31/35; N3 11/13 and NX 1/1. There was only one in-field failure among 28 patients who had pathologically negative neck specimens compared with five in 24 patients with morphologic evidence of residual disease. Of the 24 patients with pathologically positive necks, 5 were long-term survivors and were probably cured by their surgery. Another 4 died of intercurrent disease without documented recurrence of their head and neck cancer. Ten patients recurred at their primary sites (5-year actuarial control 79%) and 8 developed distant metastases (5-year actuarial rate 20%). A total of 21 patients failed at one or more sites and none was salvaged. Five-year actuarial disease-free survival was 57% and overall survival 38%. Nine patients (17%) sustained significant complications following neck dissection.

CONCLUSIONS

In patients with advanced neck disease who are treated primarily with radical radiotherapy, planned neck dissection provides excellent regional control and appears to cure a subset of patients. However, routine neck dissection adds significant morbidity to treatment and should ideally be avoided in those patients in whom surgery is either unnecessary (no residual tumor) or futile (unsalvageable disease recurrence outside the dissected neck). Based on our analysis and other recently reported series, we now recommend observing patients who have a complete response to high-dose radiotherapy (+/- chemotherapy). The ability of PET imaging to detect residual viable tumor in the head and neck or at distant sites is under investigation.

Accelerated hyperfractionated radiotherapy for locally advanced cervix cancer

PURPOSE

A phase II trial was designed to evaluate the toxicity and outcome of patients with locally advanced cervix cancer treated with accelerated hyperfractionated radiotherapy (AHFX).

METHODS AND MATERIALS

In this prospective trial, AHFX doses of 1.25 Gy were administered twice daily at least 6 hours apart to a total pelvic dose of 57.5 Gy. A booster dose was then administered via either low-dose rate brachytherapy or external beam therapy to a smaller volume. All patients were accrued and treated at Peter MacCallum Cancer Institute (PMCI) between 1986 until April 1991.

RESULTS

Sixty-one eligible patients were enrolled in this protocol; 2 (3.2%) had Stage IIB; 42 (68.9%) had Stage III; 8 (13.1%) had Stage IV and 9 (14.8%) had recurrent cervical cancer. Fifty-two patients (85%) completed the planned external beam without a treatment break. Thirty patients had acute toxicity that required regular medication. One patient died of acute treatment related toxicity. Fifty-five patients received booster therapy: 45 with intrauterine brachytherapy, 6 with interstitial brachtherapy, and 4 with external beam. The median follow-up of surviving patients was 6 years. Overall 5-year survival is 27% and 5-year relapse free survival is 36%. Nineteen patients died with pelvic disease and the actuarial local control rate was 66%. There were 8 severe late complications observed in 7 patients. Seven required surgical intervention (an actuarial rate of 27%). Five patients also required total hip replacement.

CONCLUSIONS

The local control rate was favorable compared with other series that have used standard fractionation, although overall survival remained similar. The severe late complication rate was high for this protocol and higher than similar protocols reported in the literature.

First reported case of endometrial carcinoma in association with HIV infection

Endometrial adenocarcinoma is the most common gynecologic cancer in developed countries, although it has never before been documented in a female infected with human immunodeficiency virus (HIV). By contrast, cervical carcinoma is well described in association with HIV infection and in 1993 was added to the AIDS case definition. We present the unique case of a 38-year-old HIV-infected female with endometrial carcinoma, who became rapidly disseminated following her initial surgery. Although HIV is unlikely to have an etiologic role in endometrial carcinoma, it is conceivable that immunosuppression contributed to an accelerated course of her malignancy.