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1.
BJOG ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38812271

RESUMO

OBJECTIVE: To investigate the prevalence and severity of pelvic floor disorders (PFD), and the associations between treatment type and PFD, and cancer stage and PFD in patients before and after hysterectomy for gynaecological cancer; and the changes in outcomes over time. DESIGN: Longitudinal cohort study. SETTING: Gynaecological oncology outpatient clinics. POPULATION: Patients undergoing hysterectomy for endometrial, uterine, ovarian or cervical cancer. METHODS: Participants were assessed before, and 6 weeks and 3 months after hysterectomy. Changes over time were analysed using generalised estimating equations or linear mixed models. Associations were analysed using logistic regression models and analyses of variance. MAIN OUTCOME MEASURES: Incontinence Severity Index, Pelvic Floor Distress Inventory-short form (PFDI-20), Female Sexual Function Index. RESULTS: Of 277 eligible patients, 126 participated. Prevalence rates of PFD were high before (urinary incontinence [UI] 66%, faecal incontinence [FI] 12%, sexual inactivity 73%) and after (UI 59%, FI 14%, sexual inactivity 58%) hysterectomy. Receiving adjuvant therapy led to moderate-to-very severe UI 3 months after surgery compared with surgery only (odds ratio 4.98, 95% CI 1.63-15.18). There was no association between treatment type and other PFD, or cancer stage and any PFD. CONCLUSION: Prevalence of PFD was high before and after hysterectomy for gynaecological cancer. Moderate-to-very-severe UI was associated with adjuvant therapy.

2.
Support Care Cancer ; 31(10): 589, 2023 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-37740820

RESUMO

PURPOSE: To assess the feasibility and clinical outcomes of telehealth-delivered pelvic floor muscle training (PFMT) for urinary incontinence (UI) and/or faecal incontinence (FI) after gynaecological cancer surgery. METHODS: In this pre-post cohort clinical trial, patients with incontinence after gynaecological cancer surgery underwent a 12-week physiotherapist-supervised telehealth-delivered PFMT program. The intervention involved seven videoconference sessions with real-time feedback from an intra-vaginal biofeedback device and a daily home PFMT program. Feasibility outcomes included recruitment, retention, engagement and adherence rates. Clinical outcomes were assessed at baseline, immediately post-intervention and a 3-month post-intervention using International Consultation on Incontinence questionnaires for UI (ICIQ-UI-SF) and Bowel function (ICIQ-B) and the intra-vaginal biofeedback device. Means and 95%CIs for all time points were analysed using bootstrapping methods. RESULTS: Of the 63 eligible patients, 39 (62%) consented to the study. Three participants did not complete baseline assessment and were not enrolled in the trial. Of the 36 participants who were enrolled, 32 (89%) received the intervention. Retention was 89% (n=32/36). The majority of participants (n=30, 94%) demonstrated high engagement, attending at least six videoconference sessions. Adherence to the daily PFMT program was moderate, with 24 participants (75%) completing five-to-seven PFMT sessions per week during the intervention. All clinical outcomes improved immediately post-intervention; however, the magnitude of these improvements was small. CONCLUSION: Telehealth-delivered PFMT may be feasible to treat incontinence after gynaecological cancer surgery. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: ACTRN12621000880842).


Assuntos
Incontinência Fecal , Neoplasias , Telemedicina , Feminino , Humanos , Estudos de Viabilidade , Incontinência Fecal/etiologia , Incontinência Fecal/terapia , Diafragma da Pelve
3.
Support Care Cancer ; 30(3): 2821-2827, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34846570

RESUMO

INTRODUCTION: Malignant small bowel obstruction (MSBO) occurs in up to 50% of women with advanced epithelial ovarian cancer (EOC) causing symptom burden and distress to women and their families, particularly in the terminal stages of the disease. Corticosteroids are used to promote symptom resolution in malignant small bowel obstruction (MSBO) related to EOC, with little published data on their efficacy, optimal dosing and duration of treatment. OBJECTIVE: To evaluate the efficacy of dexamethasone in achieving symptom control in women with advanced EOC presenting with MSBO, assess dexamethasone dosing and efficacy over subsequent presentations, and examine differences in dexamethasone responsiveness between platinum-resistant and platinum-sensitive patient. METHODS: This is a retrospective cohort study of women presenting with MSBO due to advanced EOC over a 12-year period from January 2005 to December 2016 in a single tertiary hospital. RESULTS: Ninety-one women with MSBO were administered dexamethasone over 154 admissions with 89% of women initially achieving partial or complete symptom control. Dexamethasone responsiveness did not change with recurrent admissions, and platinum responsive patients were more likely to respond to dexamethasone than platinum-resistant patients (OR 3.6 [95%CI 1.1 to 12.2, p = 0.04]). A total of 15.6% of patients required additional measures to control symptoms of MSBO, and 44.8% had adequate symptom resolution to allow them to remain on or commence further treatment for EOC. CONCLUSION: Dexamethasone therapy is a useful adjunctive therapy in the management of symptoms associated with MSBO in women with EOC.


Assuntos
Neoplasias Epiteliais e Glandulares , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário/tratamento farmacológico , Dexametasona , Feminino , Humanos , Recidiva Local de Neoplasia , Neoplasias Epiteliais e Glandulares/complicações , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/tratamento farmacológico , Estudos Retrospectivos
4.
Aust N Z J Obstet Gynaecol ; 61(4): 569-575, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33939180

RESUMO

BACKGROUND: A renewed National Cervical Screening Program (NCSP) was introduced in Australia in December 2017. Under the renewed NCSP, there are limited data to guide the management of discordant colposcopy and biopsy results after a liquid-based cytology (LBC) finding of 'possible high-grade squamous intraepithelial lesion' (pHSIL). AIMS: This study aims to determine the proportion of women referred with pHSIL who are found to have HSIL, identify influencing factors of women most at risk, and examine the role that cytopathology review plays in management decisions. MATERIALS AND METHODS: Two-hundred and thirty-two women presenting to a tertiary women's hospital in Australia with pHSIL since December 2017 were identified. Women with HSIL following colposcopy directed biopsy were referred for treatment. When HSIL was not identified, these patients were referred for multidisciplinary clinicopathological review. Pathological outcomes and treatment recommendations are included. MAIN OUTCOME MEASURES: The primary outcome of the study was histological confirmation of HSIL. RESULTS: Primary outcome data were available for 182 women (78.5%); 62 (34.1%) had HSIL on histology, three (1.7%) had adenocarcinoma in situ (AIS) and one (1%) had cervical squamous cell carcinoma (SCC). There was no association between age and the presence of HSIL. The presence of human papillomavirus 16 and/or 18 increased the likelihood of HSIL on histology (relative risk 1.9; 95% CI 1.27-2.80, P = 0.002). Fifty-nine (25.4%) women were referred for observation who had low-grade squamous intraepithelial lesion/no dysplasia. CONCLUSIONS: Clinicopathological review optimises management and triage of patients with pHSIL on referral cytology. Understanding outcomes in these patients informs counselling and management.


Assuntos
Carcinoma de Células Escamosas , Infecções por Papillomavirus , Lesões Intraepiteliais Escamosas Cervicais , Lesões Intraepiteliais Escamosas , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Colposcopia , Detecção Precoce de Câncer , Feminino , Humanos , Papillomaviridae , Lesões Intraepiteliais Escamosas Cervicais/diagnóstico , Esfregaço Vaginal , Displasia do Colo do Útero/diagnóstico
5.
BMJ Open ; 10(2): e034579, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-32111617

RESUMO

INTRODUCTION: Gynaecological cancers collectively account for almost 10% of cancer diagnoses made in Australian women. The extent of variation in gynaecological cancer survival rates and treatment outcomes across Australia is not well documented. The purpose of the clinical quality registry described in this paper is to systematically monitor and improve quality of care provided to these women, and facilitate clinical process improvements to ensure better patient outcomes and greater adherence to best practice care. The registry infrastructure has been developed in conjunction alongside the inaugural ovarian, tubal and peritoneal (OTP) module, allowing for concurrent piloting of the methodology and one module. Additional tumour modules will be developed in time to cover the other gynaecological tumour types. METHOD AND ANALYSIS: The National Gynae-Oncology Registry (NGOR) aims to capture clinical data on all newly diagnosed cancers of the uterus, ovary, fallopian tubes, peritoneum, cervix, vulva and vagina in Australia with a view to using these data to support improved clinical care and increased adherence to 'best practice'. Data are sourced from existing clinical databases maintained by clinicians and/or hospital gynaecological cancer units. A pilot phase incorporating only OTP cancers has recently been conducted to assess the feasibility of the registry methodology and assess the support of a quality initiative of this nature among clinicians and other key stakeholders. ETHICS AND DISSEMINATION: The NGOR has received National Mutual Acceptance (NMA) ethics approval from Monash Health Human Research Ethics Committee (HREC), NMA HREC Reference Number: HREC/17/MonH/198. We also have approval from Mercy Health HREC and University of Tasmania HREC. Data will be routinely reported back to participating sites illustrating their performance against measures of agreed best practice. It is through this feedback system that the registry will support changes to quality of care and improved patient outcomes.


Assuntos
Comitês de Ética em Pesquisa , Neoplasias dos Genitais Femininos , Sistema de Registros , Austrália/epidemiologia , Bases de Dados Factuais , Feminino , Neoplasias dos Genitais Femininos/epidemiologia , Neoplasias dos Genitais Femininos/terapia , Humanos
6.
Br J Cancer ; 116(12): 1627-1637, 2017 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-28463959

RESUMO

BACKGROUND: The relationship between diet and survival after ovarian cancer diagnosis is unclear as a result of a limited number of studies and inconsistent findings. METHODS: We examined the association between pre-diagnostic diet and overall survival in a population-based cohort (n=811) of Australian women diagnosed with invasive epithelial ovarian cancer between 2002 and 2005. Diet was measured by validated food frequency questionnaire. Deaths were ascertained up to 31 August 2014 via medical record review and Australian National Death Index linkage. We conducted Cox proportional hazards regression analysis, controlling for diagnosis age, tumour stage, grade and subtype, residual disease, smoking status, body mass index, physical activity, marital status, and energy intake. RESULTS: We observed improved survival with highest compared with lowest quartile of fibre intake (hazard ratio (HR)=0.69, 95% CI: 0.53-0.90, P-trend=0.002). There was a suggestion of better survival for women with highest compared with lowest intake category of green leafy vegetables (HR=0.79, 95% CI: 0.62-0.99), fish (HR=0.74, 95% CI: 0.57-0.95), poly- to mono-unsaturated fat ratio (HR=0.76, 95% CI: 0.59-0.98), and worse survival with higher glycaemic index (HR=1.28, 95% CI: 1.01-1.65, P-trend=0.03). CONCLUSIONS: The associations we observed between healthy components of diet pre-diagnosis and ovarian cancer survival raise the possibility that dietary choices after diagnosis may improve survival.


Assuntos
Dieta , Neoplasias Epiteliais e Glandulares/mortalidade , Neoplasias Ovarianas/mortalidade , Idoso , Austrália/epidemiologia , Estudos de Coortes , Gorduras Insaturadas na Dieta , Fibras na Dieta , Ácidos Graxos Monoinsaturados , Feminino , Índice Glicêmico , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/patologia , Modelos de Riscos Proporcionais , Alimentos Marinhos , Inquéritos e Questionários , Taxa de Sobrevida , Verduras
7.
Int J Gynecol Cancer ; 26(8): 1415-20, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27488216

RESUMO

OBJECTIVE: Risk reducing salpingooophorectomy is recommended to women with a BReast CAncer susceptibility gene (BRCA) 1 or 2 germline mutation to reduce the risk of ovarian cancer. The incidence of unsuspected neoplasia varies in the literature. The purpose of this study was to identify the rate of unsuspected neoplasia in a high-risk Australian population, discuss their management, and assess the clinical outcome. METHOD: This is a retrospective review of all women undergoing risk reductive salpingooophorectomy between January 2006 and December 2014. The medical, operative, and pathology results were reviewed. The specimens were assessed using the Sectioning and Extensively Examining the Fimbriated End protocol to the fallopian tube, and the ovary was also examined using 2 to 3 mm sectioning. RESULTS: During the study period, 138 patients underwent risk-reducing salpingooophorectomy for a known BRCA 1 or 2 germline mutation or a high-risk personal or family history of ovarian cancer. Five patients with neoplasia were identified, 2 with invasive tubal carcinoma and 3 with serous tubal intraepithelial carcinoma (STIC), giving an overall incidence of 3.62%. Invasive tubal carcinoma occurred in 1 woman with a BRCA 1 mutation and 1 woman with a BRCA 2 mutation. The incidence of carcinoma in women with either a BRCA 1 or 2 germline mutation was subsequently 2.78%. STIC occurred in 2 women with a BRCA 1 germline mutation and 1 woman carrying a BRCA 2 germline mutation. The incidence of STIC in women with either a BRCA 1 or 2 germline mutation was subsequently 4.17%. Of the patients with STIC, all 3 remain disease free at an average follow-up period of 79.33 months. CONCLUSIONS: In this retrospective review, we found the incidence of neoplasia within a high-risk Australian population undergoing risk-reducing bilateral salpingo-oophorectomy to be 3.62%. The incidence of STIC was 2.17%. During our follow-up period, all patients with STIC remained disease free.


Assuntos
Carcinoma in Situ/epidemiologia , Carcinoma in Situ/patologia , Neoplasias das Tubas Uterinas/epidemiologia , Neoplasias das Tubas Uterinas/patologia , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/patologia , Adulto , Idoso , Austrália/epidemiologia , Carcinoma in Situ/diagnóstico , Carcinoma in Situ/prevenção & controle , Neoplasias das Tubas Uterinas/diagnóstico , Neoplasias das Tubas Uterinas/prevenção & controle , Tubas Uterinas/patologia , Tubas Uterinas/cirurgia , Feminino , Genes BRCA1 , Genes BRCA2 , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Incidência , Pessoa de Meia-Idade , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/prevenção & controle , Ovário/patologia , Ovário/cirurgia , Estudos Retrospectivos , Salpingo-Ooforectomia
8.
Int J Gynecol Cancer ; 21(9): 1679-83, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21997173

RESUMO

BACKGROUND: There is a growing interest to apply the sentinel node (SN) procedure in the treatment of vulvar cancer. Previous vulvar surgery might disrupt lymphatic patterns and thereby decrease SN detection rates, lengthen scintigraphic appearance time (SAT), and increase SN false-negative rate. The aims of this study were to evaluate the SN detection rates at the Mercy Hospital for Women in Melbourne and to investigate whether previous vulvar surgery affects SN detection rates, SAT, and SN false-negative rate. METHODS: Data on all patients with vulvar cancer who underwent an SN procedure (blue dye, technetium, or combined technique) from November 2000 to July 2010 were retrospectively collected. RESULTS: Sixty-five SN procedures were performed. Overall detection rate was 94% per person and 80% per groin. Detection rates in the group of patients who underwent previous excision of the primary tumor were not lower compared with the group without previous surgery or with just an incisional biopsy. There was no statistical significant difference in SAT between the previous excision group and the other patients. None of the patients with a false-negative SN had undergone previous excision. CONCLUSIONS: Results indicate that previous excision of a primary vulvar malignancy does not decrease SN detection rates or increase SN false-negative rate. Therefore, the SN procedure appears to be a reliable technique in patients who have previously undergone vulvar surgery. Previous excision did not significantly lengthen SAT, but the sample size in this subgroup analysis was small.


Assuntos
Linfonodos/patologia , Biópsia de Linfonodo Sentinela/métodos , Neoplasias Vulvares/patologia , Neoplasias Vulvares/cirurgia , Idoso , Reações Falso-Negativas , Feminino , Humanos , Excisão de Linfonodo , Linfonodos/cirurgia , Estudos Retrospectivos , Biópsia de Linfonodo Sentinela/normas
9.
Acta Cytol ; 54(5 Suppl): 793-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21053542

RESUMO

BACKGROUND: Well-differentiated papillary mesothelioma (WDPM) is an uncommon tumor usually arising in the peritoneum and mostly an incidental finding during abdominal and pelvic surgery. Its natural history and association with other neoplasms is not clearly understood. We present a rare case of WDPM in association with high-grade endometrial carcinoma. To our knowledge, there are only two previously reported cases in the English literature of WDPM in association with endometrial carcinoma. CASE: A 62-year-old woman underwent pelvic surgery for a high-grade endometrial adenocarcinoma. At laparotomy an extensive peritoneal nodular fibrotic reaction was present, raising the clinical possibility of metastatic disease; however, intraoperative frozen section reported this as a mesothelial reaction. Cytologic examination of peritoneal washings revealed cohesive clusters of reactive-appearing mesothelial cells, some with papillary morphology, and no evidence of adenocarcinoma. The peritoneal biopsies showed no metastatic carcinoma. The endometrial tumor was an endometrioid adenocarcinoma. CONCLUSION: The cytologic diagnosis of WDPM may be difficult because it is an uncommon entity and there are overlapping features with other neoplastic and nonneoplastic lesions of the female genital tract and peritoneum. Compounding this, WDPM may occur in association with other neoplasms. We highlight the potential for surgical and pathologic misinterpretation of this entity.


Assuntos
Carcinoma Papilar/complicações , Carcinoma Papilar/patologia , Diferenciação Celular , Neoplasias do Endométrio/complicações , Neoplasias do Endométrio/patologia , Mesotelioma/complicações , Mesotelioma/patologia , Carcinoma Papilar/diagnóstico , Agregação Celular , Neoplasias do Endométrio/diagnóstico , Feminino , Secções Congeladas , Humanos , Mesotelioma/diagnóstico , Pessoa de Meia-Idade
10.
Int J Gynecol Cancer ; 19(7): 1276-80, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19823065

RESUMO

OBJECTIVES: The aim of the current study was, first, to determine whether laterality of lymph node metastases has prognostic significance, independent of the number of lymph node metastases. Second was to determine the prognostic significance of extracapsular spread irrespective of the number of lymph node metastases. METHODS: Data on 134 patients with stage III/IVA vulva cancer from 1982 till 2004 and treated with curative intent in either the Academic Medical Centre in Amsterdam or the Mercy Hospital for Women in Melbourne were reviewed. The impact of the number of lymph node metastases, extracapsular spread, and bilateral existence of lymph node metastases on survival was determined. RESULTS: The bilateral presence of lymph node metastases is not a significant predictor for survival if a correction is made for the number of lymph node metastases (hazards ratio, 1.31; 95% confidence interval, 0.68-2.51; P = 0.420). If extracapsular spread is put into the model as well, this is the only parameter of prognostic significance in multivariate analysis (hazards ratio, 5.27; 95% confidence interval, 2.60-10.67; P < 0.001). The five-year survival of patients with extracapsular spread is only 31%, which is considerably lower than the 80% survival of patients with only intracapsular metastases. CONCLUSIONS: In conclusion, there is growing evidence that bilateral existence of lymph node metastases is not a sufficient variable to qualify stage. Extracapsular spread, however, seems to be the most valuable lymph node-associated prognostic factor for survival.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patologia , Neoplasias Vulvares/diagnóstico , Neoplasias Vulvares/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/mortalidade , Feminino , Seguimentos , Humanos , Excisão de Linfonodo , Metástase Linfática , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Neoplasias Vulvares/mortalidade
11.
Int J Gynecol Pathol ; 24(4): 363-8, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16175083

RESUMO

Dysfunction of proteins involved in the G1 to S transition of the cell cycle, such as p16(INK4A) and RB1, is common in many cancer types. A screen of p16 protein expression was performed in benign, borderline, and invasive ovarian tumors, together with endometrial cancers, aligned on a tissue microarray. We observed frequent p16 overexpression in serous papillary carcinomas of ovarian and endometrial origin. An extended cohort of ovarian serous papillary carcinomas was examined to further evaluate the frequency of p16 overexpression. Strong, uniform staining in the majority of cancer cells occurred commonly in invasive serous papillary ovarian cancers, particularly in grade 3 carcinomas. RB1 protein expression abnormalities were rare. Our data indicate that abnormalities in the retinoblastoma pathway, as determined by p16 overexpression, are common in serous papillary carcinomas and are probably an early event.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/análise , Cistadenocarcinoma Papilar/metabolismo , Neoplasias Ovarianas/metabolismo , Proteína do Retinoblastoma/fisiologia , Adulto , Cistadenocarcinoma Papilar/química , Cistadenocarcinoma Papilar/patologia , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Ovarianas/química , Neoplasias Ovarianas/patologia
12.
Gynecol Oncol ; 84(3): 388-93, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11855875

RESUMO

OBJECTIVE: There are no data available on the impact of performance status on outcome in patients with vulvar cancer. It was the objective of this study to determine the impact of performance status on survival in a group of elderly patients. METHODS: A retrospective review of records of patients with vulvar cancer aged 80 years or greater and treated in a gynecological referral center was performed. Multiple clinical and pathological variables together with performance status were assessed and the impact on overall survival was determined both by univariate and multivariate analysis. RESULTS: Of 75 patients aged 80 years or older, 57 (76%) had standard treatment. The patients who had standard treatment were characterized by an earlier clinical stage and a better performance status compared with patients who had nonstandard treatment. When preoperatively available parameters of all patients were assessed in relation to survival in the total group, Eastern Cooperative Oncology Group (ECOG) performance status was the only independent prognostic indicator for survival. When all clinical and histopathological variables were assessed in the subgroup who had standard treatment, both ECOG performance status and extracapsular lymph node involvement were independent prognostic variables for overall survival. Age was not a significant prognostic variable. CONCLUSIONS: ECOG performance status is the only available pretreatment variable with independent prognostic value for survival in this group of elderly patients with vulvar cancer. These data show the importance of individualizing the treatment of patients with vulvar cancer. Performance status takes a more important place than age in the management process of these patients.


Assuntos
Índice de Gravidade de Doença , Neoplasias Vulvares/mortalidade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Neoplasias Vulvares/patologia , Neoplasias Vulvares/terapia
13.
Microbiology (Reading) ; 143(1): 259-266, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33711854

RESUMO

In timber infested by brown-rot fungi, a rapid loss of strength is attributed to production of hydroxyl radicals (HO.). The hydroxyl radicals are produced by the Fenton reaction [Fe(II)/H2O2], but the pathways leading to Fe(II) and H2O2 have remained unclear. Cellobiose dehydrogenase, purified from cultures of Coniophora puteana, has been shown to couple oxidation of cellodextrins to conversion of Fe(III) to Fe(II). Two characteristics of brown rot are release of oxalic acid and lowering of the local pH, often to about pH 2. Modelling of Fe(II) speciation in the presence of oxalate has revealed that Fe(II)-oxalate complexes are important at pH 4-5, but at pH 2 almost all Fe(II) is in an uncomplexed state which reacts very slowly with dioxygen. Diffusion of Fe(II) away from the hyphae will promote conversion to Fe(II)-oxalate and autoxidation with H2O2 as product. Thus the critical Fe(II)/H2O2 combination will be generated at a distance, enabling hydroxyl radicals to be formed without damage to the hyphae.

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