Biomedical subjects

J Broome

Publications and source records attributed to J Broome.

At least 19 recordsLinked to original sources

PubMed2006

Genetic and metabolic predictors of chemosensitivity in oligodendroglial neoplasms.

The -1p/-19q genotype predicts chemosensitivity in oligodendroglial neoplasms, but some with intact 1p/19q also respond and not all with 1p/19q loss derive durable benefit from chemotherapy. We have evaluated the predictive and prognostic significance of pretherapy (201)Tl and (18)F-FDG SPECT and genotype in 38 primary and 10 recurrent oligodendroglial neoplasms following PCV chemotherapy. 1p/19q loss was seen in 8/15 OII, 6/15 OAII, 7/7 OIII, 3/11 OAIII and was associated with response (Fisher-Exact: P=0.000) and prolonged progression-free (log-rank: P=0.002) and overall survival (OS) (log-rank: P=0.0048). Response was unrelated to metabolism, with tumours with high or low metabolism showing response. Increased (18)F-FDG or (201)Tl uptake predicted shorter progression-free survival (PFS) in the series (log-rank: (201)Tl P=0.0097, (18)F-FDG P=0.0170) and in cases with or without the -1p/-19q genotype. Elevated metabolism was associated with shorter OS in cases with intact 1p/19q (log-rank: (18)F-FDG P=0.0077; (201)Tl P=0.0004) and shorter PFS in responders (log-rank: (18)F-FDG P=0.005; (201)Tl P=0.0132). (201)Tl uptake and 1p/19q loss were independent predictors of survival in multivariate analysis. In this initial study, (201)Tl and (18)F-FDG uptake did not predict response to PCV, but may be associated with poor survival following therapy irrespective of genotype. This may be clinically useful warranting further study.

Adult↗

PubMed2006

Expression of survivin, platelet-derived growth factor A (PDGF-A) and PDGF receptor alpha in primary central nervous system lymphoma.

PURPOSE: Primary central nervous system lymphomas (PCNSL) are rare tumours occurring in the brain. Their biology and the factors predicting survival are not well known. This study investigated expression of the antiapoptotic protein survivin and platelet-derived growth factor A (PDGF-A) and receptor (PDGFRalpha) in PCNSL. EXPERIMENTAL DESIGN: A total of 44 patients with histologically confirmed PCNSL treated between 1992 and 2004 were included in this study, and tumour specimens were investigated immunohistochemically for expression of survivin, PDGF-A and PDGFRalpha. Protein expression and clinical variables were analyzed statistically. RESULTS: Of the 44 tumours 43(98%) were diffuse large B-cell non-Hodgkin's lymphomas (NHL) and one was a T-cell NHL. Around 37 (84%) of the examined PCNSL specimens showed expression of survivin, 16 (36%) of PDGF-A and 34 (77%) of PDGFRalpha. Tumours expressing surviving co-expressed PDGFRalpha frequently and PDGF-A occasionally. Expression of the above proteins was not predictive for survival in this patient group. Except for age and therapy, no other clinical variables correlated significantly with overall survival. CONCLUSIONS: PCNSL express survivin and PDGFRalpha in the majority of investigated cases. PDGF-A is expressed less frequently. Immunohistochemical detection of these proteins does not correlate with overall survival and cannot be used as a prognostic factor.

Aged↗

PubMed2006

Clinical use of genotype to predict chemosensitivity in oligodendroglial tumors.

BACKGROUND: The -1p/-19q genotype has been associated with prolonged survival and chemosensitivity in oligodendroglial neoplasms, but the predictive and prognostic significance of genotype in the routine clinic is not established. METHODS: The authors investigated allelic imbalance in 1p36, 19q13, 17p13, 10p12-15, and 10q22-26 and p53 mutation in a cohort representative of clinical practice at their center (50 primary, 26 recurrent cases) given PCV chemotherapy between 2000 and 2003 and compared with response and outcome following PCV. RESULTS: 1p/19q loss was found in 12/19 OII, 10/23 OAII, 11/13 OIII, and 6/21 OAIII. Response, seen in 92% with 1p/19q loss, was associated with the -1p/-19q genotype (Fisher exact: p < 0.001) regardless of WHO grade or whether primary or recurrent. 1p/19q loss was an independent prognostic factor associated with longer progression-free (PFS) and overall survival (OS) (Cox regression: PFS and OS p < 0.001), with greater impact on PFS than OS in primary tumors, and OS at recurrence. 17p13 loss and p53 mutation were associated with poor prognosis in recurrent tumors and chromosome 10 loss was associated with short PFS and OS in primary tumors. Histologic subtype did not influence outcome in tumors of equivalent genotype. Genotype had greater association with response and outcome than conventional clinical factors. A total of 29% with intact 1p/19q and a variety of genetic or clinicopathologic characteristics responded in association with increased PFS and OS. CONCLUSIONS: The -1p/-19q genotype predicted response and favorable outcome following PCV chemotherapy corroborating genetic analysis to guide routine clinical management. However, some cases with intact 1p/19q also had clinical benefit.

Adult↗

PubMed2001

Characterisation of molecular alterations in microdissected archival gliomas.

Classification of gliomas according to their molecular characteristics may be important in future histopathological diagnosis. However, gliomas frequently display heterogeneity at the histological, biological and molecular level. In this study of archival diagnostic gliomas, precision microdissection was used to enrich samples in the most malignant cells or to investigate intratumoural histological heterogeneity. Analysis of tumour samples microdissected from the most aggressive regions, representative of the histopathological diagnosis, revealed PTEN mutations in 4/14 anaplastic astrocytomas, 4/13 glioblastomas and 1 gliosarcoma, but not in 19 low-grade gliomas. Using a novel PCR procedure and direct sequence analysis of the entire coding sequence, TP53 mutations were detected in 1/3 pilocytic astrocytomas, 3/13 astrocytomas, 4/14 anaplastic astrocytomas, 5/13 glioblastomas and 1 gliosarcoma. All but one of the tumours with TP53 mutation showed p53 immunopositivity, but 5 low-grade and 10 high-grade gliomas had p53 protein nuclear accumulation in the absence of detectable mutation. p53 status was unrelated to p21 expression. Neither PTEN nor TP53 mutations influenced the proliferative index or microvessel density of high-grade astrocytomas. Unusual findings include: TP53 mutation in a juvenile pilocytic astrocytoma; TP53 and PTEN mutations in a de novo glioblastoma, a gliosarcoma with identical mutations in gliomatous and sarcomatous components, and an infratentorial anaplastic astrocytoma with an earlier supratentorial grade II astrocytoma bearing the same TP53 mutation but not the PTEN mutation or loss of heterozygosity (LOH) of 10q23. Similarly, the transition to high-grade histology was associated with acquisition of PTEN mutations and 10q23.3 LOH in two de novo high-grade tumours with regions of low-grade histology.

Adolescent↗

PubMed2001

Double-blind randomized phase II study of hyperbaric oxygen in patients with radiation-induced brachial plexopathy.

BACKGROUND: Radiation-induced brachial plexopathy (RIBP) is an untreatable complication of curative radiotherapy for early breast cancer, characterized by chronic neuropathic pain and limb paralysis. Hyperbaric oxygen (HBO2) therapy is known to promote healing of tissue rendered ischaemic by radiotherapy, but is untested in RIBP. METHODS: Thirty four eligible research volunteers suffering from RIBP were randomized to HBO2 or control group. The HBO2 group breathed 100% oxygen for 100 min in a multiplace hyperbaric chamber on 30 occasions over a period of 6 weeks. The control group accompanied the HBO2 group and breathed a gas mixture equivalent to breathing 100% oxygen at surface pressure. All volunteers and investigators, except the operators of the hyperbaric chamber and the trial statistician, were blind to treatment assignments. The warm sensory threshold, which measures the function of small sensory fibres, was selected as the primary endpoint. FINDINGS: Pre-treatment neurophysiological tests were grossly abnormal in the affected hand compared to the unaffected hand in both HBO2 and control groups, as expected, but no statistically significant differences were noted in either group at any time up to 12 months post-treatment. However, normalization of the warm sensory threshold in two of the HBO2 group was reliably recorded. Two cases with marked chronic arm lymphoedema reported major and persistent improvements in arm volume for at least 12 months after treatment with HBO2. IINTERPRETATION: There is no reliable evidence to support the hypothesis that HBO2 therapy slows or reverses RIBP in a substantial proportion of affected individuals, although improvements in warm sensory threshold offer some suggestion of therapeutic effect. Improvement in long-standing arm lymphoedema was not anticipated, and justifies further investigation.

Action Potentials↗

PubMed2001

Ultrasound in the quantification of female pelvic organ prolapse.

OBJECTIVES: To evaluate the use of ultrasound in the quantification of prolapse and compare findings with clinical assessments obtained in a blind study. METHODS: In a prospective comparative clinical study, 145 patients referred for urogynecological assessment were examined clinically by one operator and by translabial ultrasound by another operator. RESULTS: Clinical staging and International Continence Society coordinates were obtained for all 145 patients, as were ultrasound coordinates for descent of the anterior and posterior vaginal walls. Eighteen percent of the uteri of those women who had not had a hysterectomy in the past could not be seen; none of these women suffered from uterine prolapse clinically. Correlation with the prolapse assessment system recently endorsed by the International Continence Society was good (r = 0.77 for uterine prolapse, r = 0.72 for anterior vaginal wall and r = 0.53 for posterior vaginal wall descent). CONCLUSIONS: This study demonstrates that translabial ultrasound can be used to quantify female pelvic organ prolapse. Correlation with the International Continence Society prolapse assessment system is good. The method may be particularly suitable for objective outcome assessment after surgical intervention.

Cross-Over Studies↗

PubMed2001

Surgical outcomes of a randomized prospective trial involving patients with a proximal femoral fracture.

BACKGROUND: An orthopaedic management/patient-focused care unit (OMPFCU) involving a dedicated orthopaedic-geriatrics liaison team was established at the Royal Brisbane Hospital in 1994 in an effort to safely accelerate rehabilitation of patients with proximal femoral fractures. METHODS: The surgical outcomes of the patients were monitored in order to determine whether accelerated rehabilitation had any significant adverse effects on the surgical outcomes, measured by mortality, readmission to hospital, deep wound infection, fracture union delay, mobility and the revision surgery rate. RESULTS: No significant difference was recorded in mortality and morbidity, deep wound infection and revision surgery rates between patients in the Royal Brisbane Hospital OMPFCU and those in standard care in the orthopaedic surgery wards. CONCLUSION: Accelerated rehabilitation for patients with a proximal femoral fracture in a major teaching hospital can be accomplished safely.

Canes↗

PubMed2001

Primary intradural classic chondrosarcoma: case report and literature review.

OBJECTIVE AND IMPORTANCE: The exact origin of rare intradural chondrosarcomas remains obscure. We present a case report of an intradural classic chondrosarcoma (a very rare subtype of chondrosarcoma in this location), with a review of the literature, in an attempt to clarify the histogenesis of these tumors. CLINICAL PRESENTATION: A 48-year-old man presented with a 12-month history of progressive right hemiparesis. Computed tomography and magnetic resonance imaging demonstrated a left parietal space-occupying lesion. INTERVENTION: The patient underwent an image-guided, left parietal parasagittal craniotomy. An extrinsic tumor, which seemed to arise from the dura, was macroscopically removed. There was no bone involvement. The histological examination revealed a Grade II classic chondrosarcoma with tumor infiltration into the dura. Adjuvant radiotherapy was administered. CONCLUSION: Intradural chondrosarcomas are rare tumors, the majority of which are mesenchymal. Classic chondrosarcomas in this location are much rarer. Their histogenesis is uncertain. In this case, the origin seems to be from the dura. Because of the malignant potential of these tumors, radical extirpation whenever possible, followed by radiotherapy, is indicated.

Chondrosarcoma↗

PubMed2000

Molecular genetic analysis of archival gliomas using diagnostic smears.

Investigation of the clinical significance of genetic alterations in gliomas requires molecular genetic analysis using samples from retrospective or prospective clinical studies. However, diagnostic tissue is often severely limited and because of fixation, paraffin-embedded tissues (PET) contain degraded DNA. Intra-operative cytological preparations (smears) archived after diagnosis may represent an additional source of clinical material for genetic analysis. In this study, tissue samples were obtained by precision microdissection of archived diagnostic smears from 20 cases (1961-1999). All samples produced polymerase chain reaction (PCR) products for the beta globin gene, but the most recent samples amplified best and gave longer amplimers. For six cases, direct comparison was made between samples microdissected from smears and the corresponding PET. Samples from smears showed improved PCR performance and similar alleles on microsatellite marker analysis. One case, with smears of uninvolved cortex and tumour tissue available for microdissection, showed allelic imbalance at 10q23 on the basis of the smear results alone. PCR products from smears were shown to be suitable for direct sequence analysis (p53 gene). A PTEN mutation, found previously in an anaplastic astrocytoma by analysis of PET, was detected in the corresponding diagnostic smear. The results of this study indicate that tissue samples microdissected from diagnostic intra-operative cytological preparations may be suitable for molecular genetic analysis of gliomas.

Archives↗

PubMed2000

Regulated expression of cytokines in human endometrium throughout the menstrual cycle: dysregulation in habitual abortion.

It is widely assumed that, after ovulation, the human endometrium undergoes specific changes and becomes receptive to the implantation of embryo during the mid-secretory phase. When implantation does not take place, further changes occur which eventually result in the shedding of human endometrium. The present study was carried out to examine whether there are changes in the cytokine gene expression in human endometrium which are correlated with endometrial function in various phases of the menstrual cycle. The RNase protection assay was performed on carefully dated endometria from normal subjects to characterize the expression of cytokines which potentially contribute to endometrial function. These included: tumour necrosis factor (TNF), interleukin (IL)-1beta, IL-6, IL-8, leukaemia inhibitory factor (LIF), transforming growth factor beta1 (TGF-beta1), macrophage colony stimulating factor (MCSF or colony stimulating factor-1), and vascular endothelial growth factor (VEGF) mRNAs. A low level of expression of these cytokine mRNAs was found during the proliferative and early secretory phase. Expression of cytokine mRNA increased during the mid-secretory phase and rose to a peak in the late secretory phase. The level of cytokine mRNA expression during gestation was most akin to that observed during the mid-secretory phase. Individuals with habitual abortion presented with an abnormal expression of IL-1beta and IL-6 mRNA in endometrium, during the mid-secretory phase. Taken together, these findings are consistent with a progressive rise in the expression of cytokines in human endometrium during the secretory phase in natural cycles. Furthermore, the findings show that habitual abortion is associated with the abnormal expression of IL-1beta and IL-6 in the mid-secretory phase.

Abortion, Habitual↗

PubMed1999

Isolation of a novel gene, TSP50, by a hypomethylated DNA fragment in human breast cancer.

A novel gene, testes-specific protease 50 (TSP50), was isolated from a human testes cDNA library by using a genomic DNA probe, BR50. BR50 was isolated by a modified representational difference analysis (RDA) technique due to its hypomethylated feature in a breast cancer biopsy. This altered DNA methylation status was also detected by BR50 in other breast and some ovarian cancer tissues. The TSP50 gene product is a homologue to several human proteases, which indicates that it may encode a protease-like protein. Northern analysis of 16 different types of normal human tissues suggests that TSP50 was highly and specifically expressed in human testes, which indicates that it might possess a unique biological function(s) in that organ. Methylation status analysis in normal human testes and other tissues showed a correlation between DNA methylation and gene expression. Most importantly, reverse transcription-PCR analysis of 18 paired breast cancer tissues found that in 28% of the cancer samples, the TSP50 gene was differentially expressed. The possibility that TSP50 may be an oncogene is presently under investigation.

Amino Acid Sequence↗

PubMed1999

From endometrial receptivity to infertility.

Implantation of the blastocyst in endometrium requires establishment of a coordinated molecular dialogue between the embryo and the endometrium. Factors instrumental in the preparation of a receptive endometrium are derived from the hypothalamic-pituitary-gonadal axis. These factors modulate the expression of genes that drive the endometrium throughout the characteristic menstrual cycles. During each menstrual cycle, a series of coordinated, architectural, morphological, cytochemical, and molecular changes ultimately lead to the preparation of a receptive endometrium during the putative "receptive period" or "implantation window." It is during this critical period that a proper dialogue can be established between an intrusive blastocyst and a receptive endometrium. If, for any reason, this dialogue is not established or is perturbed, the embryo is aborted. The natural fate of the receptive endometrium, in the absence of implantation, is development of a second set of changes that ultimately lead to menstruation. The identity of the molecular repertoire that makes endometrium receptive to implantation and/or lead to menstruation is being revealed and broadly includes cytokines, heat shock factors, adhesion molecules and matrix metalloproteases. We identified a novel gene of the transforming growth factor-beta, superfamily of molecules, the so-called endometrial bleeding--associated factor or ebaf, whose expression is confined to the late secretory and menstrual phases. Various forms of female infertility were associated with dysregulated expression of ebaf during the implantation window. The findings show an occult molecular defect of endometrial receptivity that seems to be due to dysregulated and premature expression of a member of the premenstrual molecular repertoire. The dysregulated expression of ebaf may assist in the identification, prognostication, and monitoring of treatment of infertile women.

Embryo Implantation↗

PubMed1999

Heat shock proteins in human endometrium throughout the menstrual cycle.

Human endometrium, in response to steroid hormones, undergoes characteristic cycles of proliferation, secretory changes, and tissue shedding. Human endometrium expresses a molecular repertoire which includes the heat shock proteins (Hsps) Hsp27, Hsp60, Hsp70, Hsp90, and alpha crystallin B chain. The expression of Hsp27, Hsp60, and the constitutive form of Hsp70 (Hsc70) shows a sharp increase in human endometrium after ovulation. The maximal expression of the molecular chaperone, alpha crystallin B chain, occurs during the secretory phase. In view of known functions of the Hsps, it is likely that these proteins are involved in protection of the endometrial proteins against factors with the potential to lead to protein denaturation. Tumor necrosis factor-alpha (TNF-alpha) is a cytotoxic cytokine that is produced in progressive amounts during the secretory phase. The function of the Hsps may be to protect cells against the cytotoxic damage of TNF-alpha, particularly during the critical period of "implantation window."

Endometrium↗

PubMed1997

Placenta previa percreta with bladder invasion.

BACKGROUND: Although the clinical presentation and imaging techniques can raise suspicion for placenta previa percreta, this potentially catastrophic condition may remain undiagnosed or its extent underappreciated until delivery. The decision to proceed with definitive surgery in cases of placenta previa percreta should be carefully considered. CASE: A case of placenta previa percreta with bladder invasion was diagnosed prenatally. This case illustrates the magnitude of complications that can arise despite aggressive multidisciplinary perioperative management. CONCLUSION: When possible, hysterectomy performed for placenta previa percreta is best avoided under anything other than ideal conditions. A multidisciplinary approach for preoperative, intraoperative, and postoperative management of placenta previa percreta optimizes maternal outcome.

Adult↗

PubMed1996

The value of life and the value of population.

"This paper first distinguishes structured and unstructured approaches to valuing life. The unstructured approach bases its valuations on people's raw preferences, whereas the structured approach imposes a theoretical framework about the structure of value. The paper recommends the structured approach. This opens the way to considering the value of adding people to the population. The paper examines a common intuition that adding people is not in itself valuable, and explains the difficulties this intuition encounters."

Behavior↗

PubMed1995

Susceptibility to astrocytoma and meningioma: influence of allelism at glutathione S-transferase (GSTT1 and GSTM1) and cytochrome P-450 (CYP2D6) loci.

We describe a case-control study to identify associations between polymorphism at the cytochrome P-450 (CYP2D6) and glutathione S-transferase (GSTT1 and GSTM1) loci and susceptibility to astrocytoma and meningioma. Accordingly, genotype frequencies in 112 astrocytoma and 50 meningioma patients were compared with frequencies in 577 controls. GSTM1 genotype frequencies in these groups were not different. Logistic regression analysis showed GSTT1 null and CYP2D6 poor metabolizer were risk factors in astrocytoma (odds ratio = 2.67 P = 0.0005 and odds ratio = 4.17 P = 0.0043, respectively) and meningioma (odds ratio = 4.52, P = 0.0001 and odds ratio = 4.90, P = 0.0132, respectively) when corrected for the other variables. No interactive effects between genotypes were identified. The data suggest polymorphism at loci encoding carcinogen-metabolizing enzymes influences susceptibility to astrocytoma and meningioma, possibly by determining effectiveness in the detoxification of environmental carcinogens.

Adult↗

PubMed1995

Neurotoxicity of advanced glycation endproducts during focal stroke and neuroprotective effects of aminoguanidine.

Cerebral infarction (stroke) is a potentially disastrous complication of diabetes mellitus, principally because the extent of cortical loss is greater in diabetic patients than in nondiabetic patients. The etiology of this enhanced neurotoxicity is poorly understood. We hypothesized that advanced glycation endproducts (AGEs), which have previously been implicated in the development of other diabetic complications, might contribute to neurotoxicity and brain damage during ischemic stroke. Using a rat model of focal cerebral ischemia, we show that systemically administered AGE-modified bovine serum albumin (AGE-BSA) significantly increased cerebral infarct size. The neurotoxic effects of AGE-BSA administration were dose- and time-related and associated with a paradoxical increase in cerebral blood flow. Aminoguanidine, an inhibitor of AGE cross-linking, attenuated infarct volume in AGE-treated animals. We conclude that AGEs may contribute to the increased severity of stroke associated with diabetes and other conditions characterized by AGE accumulation.

Animals↗

PubMed1992

The human glutathione S-transferases: comparison of isoenzyme expression in normal and astrocytoma brain.

We describe expression of alpha, mu and pi class glutathione S-transferases (GST) in brain tissue from 21 controls and uninfiltrated and tumour tissue from 17 glioma patients. GST were sequentially resolved by chromatofocusing into the GST2, GST1, GST5, GST2 (5.5), GST3, GST6 sets and the contribution of each to total activity determined. The immunological identity of these isoforms was studied using immunoblotting. The pi class GST3 isoform was the major contributor to activity in control tissue (70.9%) and, uninfiltrated (75.1%) and tumour samples (82.4%). Expression was significantly greater in the tumours (P less than 0.05). Expression of alpha isoforms GST2 and GST2 (5.5) was variable with most subjects demonstrating no detectable GST2 (B1 and B2 chromatofocused monomers). An isoform termed GST2 (5.5) chromatofocussed at pH 5.5 and cross-reacted with antisera to B1. It was detected in most control and glioma patients and comprised about 5% of total activity. The contribution of GST2 and GST2 (5.5) to activity was similar in control, uninfiltrated and tumour tissue. Two mu class enzymes, GST1 and GST5, were identified. GST1 isoforms were detected in 9 of 21 control samples, the phenotype of these and matched liver samples were identical. GST1 isoforms were detected in 4 of 16 tumour samples, a significantly lower incidence than in a previously established control group. GST5 was expressed in most samples, the contribution of this locus to activity was significantly reduced in the tumours (5.2%) compared with control samples (14.5%).

Astrocytoma↗