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Biomedical subjects

R Grant

Publications and source records attributed to R Grant.

At least 37 records · Page 2Linked to original sources
PubMed2002

Erythropoietin and interleukin-1beta modulate nitrite production in a Swiss 3T3 cell model of rheumatoid synovial fibroblasts.

Erythropoietin (EPO), a haemopoietic growth factor and a primary regulator of erythropoiesis, is widely used to treat anaemia in various chronic complications of rheumatoid arthritis (RA). Fibroblast-like cells, found in the pannus tissue of joints, are thought to contribute to the inflammatory pathology of RA. Thus for the current study we investigated the effects of recombinant human EPO (rHuEPO) on NO metabolism, using an interleukin-1beta (IL-1beta)-stimulated Swiss 3T3 fibroblast monolayer as a model for fibroblast activity in RA. The results show that, over 3 days, both alone and in combination with the pro-inflammatory cytokine IL-1beta (10 ng/ml), rHuEPO (25 micro-units/ml) induced significant production of nitrite in cell culture supernatants. This is an indicator of NO production by nitric oxide synthase (NOS), which is a well-documented mediator of metalloproteinase-mediated tissue remodelling in RA. It therefore appears that, through modulation of NOS-dependent NO production, rHuEPO may influence remodelling of connective tissue in RA, independently of its established erythropoietic role.

3T3 Cells↗
PubMed2002

The outcome of voiding dysfunction managed with clean intermittent catheterization in neurologically and anatomically normal children.

OBJECTIVE: To describe the tolerability and efficacy of clean intermittent catheterization (CIC) in the management of dysfunctional voiding in patients who are neurologically and anatomically normal. PATIENTS AND METHODS: The medical records were reviewed in 23 patients (16 girls, mean age 9 years, range 6-14.5, and seven males, mean age 8 years, range 5-20.5) with urinary incontinence and/or urinary tract infection (UTI) who were offered CIC because they had a large postvoid residual urine volume (PVR). All had extensive instruction before starting CIC. All patients underwent urodynamic studies, and urinary and fecal elimination habits were recorded. Detrusor hyperactivity, when present, was treated with anticholinergic medication. The follow-up evaluation included tolerance of CIC, continence status and the incidence of UTI. Behavioural modification or biofeedback training was not used in any patient. RESULTS: Of the 23 patients, 13 presented with both UTI and urinary incontinence, five with incontinence only, four with UTI only, one with frequency and no incontinence, and one with haematuria. Associated symptoms included frequency/urgency, constipation or soiling, and straining to void or incomplete emptying (in nine each), and infrequent voiding in six. CIC was performed within 2 days by 15 patients, while four others required up to 2 weeks to master CIC. However, three of the four patients (all older girls) who needed 2 weeks to learn the technique did not tolerate CIC and discontinued it within 3 weeks. Four other adolescents (three girls and one boy) refused to learn CIC. Of the 16 patients remaining on CIC only three had cystitis; no patient had a febrile UTI. Once successfully instituted, all patients became continent while on CIC. Six boys (mean follow-up 4 months) had a marked decrease in their PVR. CIC was discontinued in three girls who voided normally to emptiness within 6 months of starting CIC; they remained dry and infection-free 16 months (two) and 6 years later. CONCLUSION: CIC is a viable therapeutic option for the treatment of dysfunctional voiding, associated with a large PVR, in the absence of any neurological abnormality. CIC is well tolerated in the sensate patient and provides a means for expeditiously achieving continence and improving bladder emptying cost-effectively.

Adolescent↗
PubMed2002

The position of the neurologist in neuro-oncology.

Neuro-oncology is a growing new subspeciality with a strong interdisciplinary character. This position paper explains the role of neurology in the multidisciplinary field of neurosurgeons, radiotherapists and general oncologists, dealing with neuro-oncological patients. The paper delineates the varied spectrum of the field of neuro-oncology which expands from primary brain tumours, to metastatic and non-metastatic effects of systemic cancer on the central and peripheral nervous system, neurotoxicity due to cancer treatment and issues of quality of life. It has been written by the scientific neuro-oncology panel of the European Federation of Neurological Societies (EFNS) to delineate the situation of neuro-oncology in Europe, and facilitate the understanding and implementation of this subspeciality in the future.

Brain Neoplasms↗
PubMed2002

Don't wait for a sensory level--listen to the symptoms: a prospective audit of the delays in diagnosis of malignant cord compression.

AIM: To report details concerning symptoms (especially pain) preceding the development of malignant cord compression (MCC); delays between onset/reporting of symptoms and confirmed diagnosis of MCC; accuracy of investigations carried out. METHODS: A prospective observational study examined the diagnosis, management and outcome of 319 patients diagnosed with MCC at three Scottish cancer centres between January 1998-April 1999. The process was considered from the perspectives of the patient, the GP and the hospital doctor. RESULTS: At diagnosis, most patients (82%) were either unable to walk or only able to do so with help. Pain was reported by nearly all patients interviewed (94%) and had been present for approximately 3 months (median=90 days). It was severe in 84% of cases, with the distribution and characteristics of nerve root pain in 79%. The site of pain did not correspond to the site of compression. Where reported, weakness and/or sensory problems had been noticed by the patient for some time before diagnosis (median intervals 20 and 12 days, respectively). Most patients reported early symptoms to their General Practitioner (GP) and diagnosis was established, following referral and investigation, approximately 2 months (median=66 days) later. CONCLUSION: Patients who develop spinal metastases are at risk of irreversible spinal cord damage. Weakness and sensory abnormalities are reported late and identified even later, despite patients having reported pain for a considerable time. Patients with cancer who describe severe back or spinal nerve root pain need urgent assessment on the basis of their symptoms, as signs may occur too late. Plain films and bone scans requested for patients in this audit predicted accurately the level of compression in only 21% and 19% of cases, respectively. The only accurate investigation to establish the presence and site of a compressive lesion is magnetic resonance imaging (MRI). A referral guideline based on suspicious symptoms in addition to suspicious signs is suggested.

Aged↗
PubMed2002

Management of patients aged >60 years with malignant glioma: good clinical status and radiotherapy determine outcome.

Many clinical trials have shown that the most important prognostic variable in patients with malignant glioma is advanced age. However, can some patients aged >60 years still have relatively good outcomes with conventional surgical and radiotherapeutic treatment? A previous audit of practice (1983-89) suggested that functional status was an important prognostic variable in the elderly. We have reviewed a further cohort (1989-96) to evaluate changes in practice and outcomes given advances in neuroimaging, neurosurgery and radiotherapy. The major findings in this series of 80 patients aged over 60 years with a histological diagnosis of supratentorial malignant glioma were: (i) There was a relationship between management undertaken and clinical status of the patients (p < 0.01), i.e. patients in good grade generally had tumour debulking and radiotherapy, whilst those in poor grade generally had only biopsy. (ii) There was a significant increase in survival of patients in the second period who received surgical debulking and post-operative radiotherapy (from a median of 23 to 41 weeks (p < 0.05). (iii) It is likely that case selection accounted for much of this improvement since there was a direct relationship between median survival time and good clinical grade using the WHO performance scale. (iv) A shorter radiotherapy course (30 Gy in six fractions) was as efficacious as a conventional course (60 Gy in 30 fractions), and those patients having radiotherapy survived significantly longer than those not having this treatment (p = 0.001). This study has again demonstrated the importance of preoperative clinical grade and radiotherapy treatment in determining outcomes in patients >60 years. To put these data in a societal context a recent prospective multicentre audit of patients with malignant glioma in Scotland, and another audit from our unit, showed that between 24 and 65% of patients aged >60 years, with a CT diagnosis of malignant glioma do not undergo either surgery or radiotherapy. Advanced age per se should not be a bar to interventional treatment in patients aged >60 years with suspected malignant glioma.

Age Factors↗
PubMed2002

How well do radiologists diagnose intracerebral tumour histology on CT? Findings from a prospective multicentre study.

The management of patients with intracranial tumours relies on accurate diagnosis of tumour type. To assess the accuracy with which tumour histology could be diagnosed from brain CT we reviewed data from a prospective, population-based study from three Scottish neuroscience centres. Between October 1997 and April 1999 all patients from the Edinburgh, Aberdeen and Dundee Neuroscience Centres with a CT-diagnosis of a solitary, supratentorial intra-cerebral tumour were recruited. General and neuroradiologists were asked to give their best guess tumour diagnosis. Biopsy confirmed neuropathological tumour type was available for comparison with best guess CT-diagnosis in 221 of 324 patients. Histological diagnosis was either malignant glioma, low grade glioma or metastasis in 199 cases. The accuracy of CT lesional diagnosis for these three categories was 60% (95% confidence interval 54-67%), 85% (80-89%) and 82% (77-88%), respectively. The diagnostic accuracy of an intra-cerebral tumour was 0.81 with a positive predictive value of 0.93. There was no significant difference between histological diagnostic accuracy of neuroradiologists and general radiologists. In 10% of patients the initial CT scan was reported as negative for intracranial tumour, with 62% of these scans having been carried out without contrast. Based on CT alone radiologists are good at identifying an intra-cerebral tumour, but not so good at distinguishing between different tumour types. The implications of the findings for patient management are discussed.

Adult↗
PubMed2001

Phase I trial of a twice-daily regimen of amifostine with ifosfamide, carboplatin, and etoposide chemotherapy in children with refractory carcinoma.

BACKGROUND: Amifostine protects normal tissues against chemotherapy and radiation-induced toxicity without loss of antitumor effects. Evidence suggests that multiple daily doses of amifostine may improve its cytoprotective effects. The purpose of this study was to assess the dose-limiting toxicities (DLTs) and maximum tolerated dose (MTD) of twice-daily doses of amifostine with ifosfamide, carboplatin, and etoposide (ICE) chemotherapy for children with refractory malignancies and to determine the pharmacokinetic properties of amifostine, WR-1065, and the disulfide metabolites of amifostine. METHODS: Patients with refractory malignancies were treated with amifostine 15 minutes before and 2 hours after chemotherapy with ifosfamide (3 g/m(2) per dose on Days 1 and 2) and carboplatin (635 mg/m(2) on Day 3). Etoposide was administered on Days 1 and 2 (150 mg/m(2)). The starting dose of amifostine was 740 mg/m(2). Pharmacokinetic studies were performed after the first dose of amifostine. RESULTS: Twelve patients received 23 courses of ICE and amifostine. Dose-limiting toxicities for amifostine at 740 mg/m(2) were somnolence and anxiety. The other Grade 3 and 4 toxicities included asymptomatic, reversible hypocalcemia, vomiting, and reversible hypotension. At a dose of 600 mg/m(2), amifostine was well tolerated. Hypocalcemia, due to rapid, transient suppression of parathyroid hormone production, required close monitoring and aggressive intravenous calcium supplementation. Pharmacokinetic studies revealed high interpatient variability with rapid plasma clearance of amifostine and WR-1065. The median elimination half-life of amifostine (9.3 minutes) and WR-1065 (15 minutes) was much shorter than the disulfide metabolites (74.4 minutes). CONCLUSIONS: The recommended pediatric dose of amifostine for a twice-daily regimen is 600 mg/m(2) per dose (1200 mg/m(2)/day) with DLTs of anxiety and somnolence, lower than the previously recommended single dose of 1650 mg/m(2).

Adolescent↗
PubMed2001

Regulation of the packaging of Bacillus thuringiensis delta-endotoxins into inclusions.

During sporulation, many Bacillus thuringiensis subspecies synthesize several related delta-endotoxins which are packaged into bipyramidal intracellular inclusions. These inclusions are solubilized in the alkaline, reducing conditions of the midguts of susceptible insect larvae and are converted by proteolysis to active toxins. The toxins insert into the membranes of cells lining the midgut and form cation-selective channels, which results in lethality. There are three delta-endotoxins, Cry1Ab3, Cry1Ca1, and Cry1Da1, present in the inclusions produced by a B. thuringiensis subsp. aizawai cell. While the ratio of the steady-state mRNAs for these three protoxins has been shown to differ (cry1Ab3/cry1Ca1/cry1Da1 mRNA ratio, 4:2:1), the half-lives of the cry1Da1 and cry1Ab3 mRNAs were found to be similar, indicating that there were differences in the transcription rates. The relative contents of these delta-endotoxins in purified inclusions from B. thuringiensis subsp. aizawai have been measured previously, and an even greater relative deficiency of the Cry1Da1 protoxin (ratio, 20:12:1) was found. In order to account for this deficiency, other steps which could be involved in inclusion formation, such as translation and packaging, were examined. The three cry genes have the same dual overlapping promoters, but the ribosome binding sequence for the cry1Da1 gene was not the consensus sequence. Translation was enhanced about fourfold by changing to the consensus sequence. In addition, the relative amount of Cry1Da1 protoxin in inclusions was twofold lower when cells were sporulated in Luria-Bertani (LB) medium than when cells were sporulated in a glucose-yeast extract medium. This difference was attributable to packaging since the relative amounts of Cry1Da1 antigen in cells sporulating in the two media were the same. Some factor(s) required for packaging of the Cry1Da1 protoxin in inclusions is apparently limiting in LB medium. Differences in the initial transcription rates, translation efficiencies, and packaging all contribute to the delta-endotoxin composition of an inclusion.

Amino Acid Sequence↗
PubMed2001

P53 alteration and microsatellite instability have predictive value for survival benefit from chemotherapy in stage III colorectal carcinoma.

PURPOSE: We recently presented evidence for tumor site and gender-specificity in the survival benefit from adjuvant chemotherapy in Stage III colorectal cancer (CRC). In the current study, we examined whether p53 alteration or the microsatellite instability (MSI) phenotype provide additional predictive information in CRC patients. EXPERIMENTAL DESIGN: A retrospective series of 891 Stage III CRC patients with negative surgical margins was investigated. Thirty percent (270 of 891) received postoperative adjuvant chemotherapy with curative intent and comprising of 5-fluorouracil/levamisole. Adjuvant treatment and nontreatment patient groups were well matched for tumor site, grade, p53 alterations, and MSI. Surgical tumor specimens were investigated for p53 overexpression using immunohistochemistry and for p53 mutation and MSI using single-strand conformation polymorphism analysis. The predictive value of these markers was evaluated by comparing the survival of adjuvant-treated and nonadjuvant treated patients. RESULTS: A strong inverse correlation was observed between p53 alteration and MSI (P < 0.0001). In univariate analysis, the factors of sex, site, p53 alteration, and MSI were each strong predictors of a survival benefit from chemotherapy. Multivariate analysis revealed that chemotherapy provided maximal survival benefit for female patients (P = 0.005) and for patients whose tumors contained normal p53 (P = 0.041). Males whose tumors contained a p53 alteration and were negative for MSI appeared not to benefit from chemotherapy. CONCLUSIONS: Our findings suggest that p53 alteration and MSI could be clinically useful molecular predictive markers for the identification of CRC patients who might benefit from 5-fluorouracil-based chemotherapy.

Adult↗
PubMed2000

Comparative genomic hybridization analysis of clear cell sarcoma of the kidney.

BACKGROUND: Clear cell sarcoma of the kidney (CCSK) is a rare malignant pediatric tumor, distinguished from the Wilms tumor by its characteristic histologic features and a more aggressive clinical behavior with a tendency to metastasize to bone. Genetic studies on CCSK are limited and no consistent findings have been reported. PROCEDURE: We examined four cases of CCSK for presence of consistent genetic alterations using comparative genomic hybridization (CGH). This is the first report concerning CGH analysis of CCSK. RESULTS: Three of the tumors showed no chromosome gains or losses. One of the tumors had gains of 1 q and the terminal end of 11 q. CONCLUSIONS: These results are consistent with previous findings of limited chromosomal changes in CCSK karyotypes. Gain of 1 q in CCSK warrants further investigation. Copy number gains of 1 q have been repeatedly demonstrated in soft tissue and bone sarcomas, as well as other tumors, implying the presence of genes involved in tumor development and/or progression.

Child↗
PubMed2000

Biopsy versus resection for malignant glioma.

BACKGROUND: Patients with isolated supratentorial brain tumours, presumed to be primary on imaging, have two surgical management options - biopsy or resection. Surgical opinions appear to be equally divided when considering the relative risks and benefits of these two procedures. OBJECTIVES: To estimate the clinical effectiveness of radical surgical resection compared to simple biopsy in patients with malignant glioma. SEARCH STRATEGY: Electronic database searches of COCHRANE CONTROLLED TRIALS REGISTER (including the Cochrane Cancer Network Specialised Register of Trials), MEDLINE, CANCERLIT, EMBASE, BIOSIS and SCIENCE CITATION INDEX. Hand searching the references of all identified studies; hand searching the Journal of Neuro-Oncology over the previous 10 years, including all conference abstracts; personal communication. SELECTION CRITERIA: Randomised and clinical controlled trials were included if they compared biopsy to resection, or looked at effect of extent of resection on survival, time to progression or quality of life, for malignant glioma patients of all ages. DATA COLLECTION AND ANALYSIS: Studies were to be identified, critically appraised and data extracted by the author (SEM). For dichotomous data, Peto odds ratios (OR) with 95% confidence intervals (CI) were hoped to have been estimated. Normal continuous data were to have been summated using the weighted mean difference (WMD). MAIN RESULTS: The electronic database search yielded 2100 citations. Of these, two articles were identified for possible inclusion, however both were excluded. The hand search and personal communication were similarly unproductive. No studies were included in the review and no data was synthesised. REVIEWER'S CONCLUSIONS: Given that no qualifying studies were identified and because this is an important issue, both in terms of patient risk and benefit and health economics, the author feels it important to conduct a randomised controlled trial in this subject.

Biopsy↗
PubMed2000

Efficacy and tolerability of 1000-4000 mg per day of levetiracetam as add-on therapy in patients with refractory epilepsy.

The aim of this study was to determine the efficacy and tolerability of 1000-4000 mg/day of levetiracetam (LEV, Keppra) as add-on treatment for refractory epilepsy. This was a dose-escalation study of 29 patients with refractory epilepsy. Patients received placebo for 4 weeks (baseline) followed by levetiracetam 1000 and 2000 mg per day each for 2 weeks, and then 3000 and 4000 mg per day each for 4 weeks. Primary efficacy was assessed by seizure frequency (number/week). Tolerability was assessed by adverse events, laboratory parameters, clinical evaluations, and electrocardiogram. All the study periods were completed by 27 of the 29 patients. A substantially lower median seizure frequency was observed at all levetiracetam dosing periods (1000 mg per day, 1.0 seizures per week; 2000 mg per day, 1.5 seizures per week; 3000 mg per day, 1.0 seizures per week; 4000 mg per day, 0.75 seizures per week) compared with the placebo treatment (2.06 seizures per week). In addition, 22-33% of these patients were seizure free during treatment with levetiracetam compared with only 14% with placebo. Levetiracetam was well tolerated. The most common adverse events were somnolence and asthenia; frequency and severity increased with increasing doses of levetiracetam. Levetiracetam in doses from 1000 to 4000 mg per day is effective. Somnolence and asthenia were more frequent with the highest dose, suggesting that 4000 mg per day may be the upper limit in some patients, although individual susceptibility to somnolence was variable.

Adolescent↗
PubMed2000

Enhanced safety and efficacy of live attenuated SIV vaccines by prevaccination with recombinant vaccines.

The only vaccines shown to be protective against intravenous challenge with virulent virus in the simian immunodeficiency virus (SIV)/macaque model are attenuated live SIVs. However, these vaccines have several disadvantages: 1) they persist indefinitely in vaccinated macaques; 2) they are pathogenic to neonatal macaques; and 3) they are lethal in some adult macaques. To enhance the safety and efficacy of these vaccines, we immunized macaques first with recombinant vaccines and then inoculated the animals with SIV(delta(nef)). In the first experiment, preimmunized macaques advanced to disease slower than controls after challenge with virulent SIV; five animals survived for 3 years without disease and only the vaccine virus (SIV(delta(nef)) could be isolated at this time. In the second experiment, preimmunized animals had lower virus loads and no disease compared to controls.

Animals↗
PubMed2000

Measurement of blood flow in the vertebral artery using colour duplex Doppler ultrasound: establishment of the reliability of selected parameters.

This study was designed to determine the reliability of the ultrasound testing procedure for evaluating vertebral artery blood flow, and to determine a robust testing protocol for future studies. Blood flow parameters were tested in ten asymptomatic subjects (mean age 33 years, standard deviation 6 years 8 months) using colour duplex Doppler imaging. Volume flow rate data at C5-6 demonstrated good reliability from a single measurement (Intraclass correlation coefficient [ICC]=0.81). Peak velocity sampled at C1-2 showed poor reliability if a single measurement was used (ICC=0.26) improving to fair levels with three measurements (ICC=0.77). Reliability for this parameter was good if five measurements were taken (ICC=0.83-0.84). Systolic/diastolic ratio measured at C5-6 showed poor reliability (ICC=0.57) if a single measurement was taken in the manner of Thiel et al. (1994). This improved to fair reliability (ICC=0.75) if the mean of three measurements was used. There was no further improvement if five measures were sampled. Sampling at C2-3 in the manner of Refshauge (1994) was found to be technically difficult and it was not possible to detect a Doppler shift in three of the ten subjects at this level. Reliability of peak velocity at C2-3 was found to be poor, regardless of whether single or multiple averaged measurements were taken (ICC=0.37-0.63). Mean (time averaged) velocity measurements at C2-3 showed poor reliability if a single measurement was taken (ICC=0.39), fair reliability if the first three measurements were averaged (ICC=0.73) and good to high reliability levels if five measurements were sampled (ICC=0.88-0.91). A review of the literature suggests that sampling volume flow rate at C5-6 and peak velocity at C1-2 represents a clinically meaningful combination of parameters to detect narrowing in the VA. The results of this current study indicate the desirability of taking a single measurement of volume flow rate at C5-6 and the mean of three measurements of peak velocity at C1-2, with the additional calculation of the standard error of measurement, if reliable results are to be achieved.

Adult↗
PubMed2000

Comparative assessment of pediatric testicular volume: orchidometer versus ultrasound.

PURPOSE: Testicular volume measurements obtained with the Prader and Rochester orchidometers were compared to those obtained using scrotal ultrasound. The ability of each orchidometer versus ultrasound in detecting volume differential between 2 testes and the accuracy of orchidometer measurement by a less experienced examiner to that of a urologist were compared. MATERIALS AND METHODS: A total of 65 males were examined by the attending urologist and urology nurse using the Prader and Rochester orchidometers, and scrotal ultrasound was subsequently performed by an attending radiologist. Statistical analysis of the results was performed to determine the correlation of orchidometer measurements between examiners, as well as with ultrasound, and sensitivity and specificity of orchidometer and ultrasound in detecting defined volume differentials between testes of 10%, 15%, 20% and 25%. RESULTS: There was a strong linear relationship between testicular volume measurements using either orchidometer and ultrasound. To detect a defined volume differential as determined by ultrasound orchidometer sensitivity was weak, whereas orchidometer specificity was better. There was a strong correlation between orchidometer measurements of the urology nurse and attending urologist. CONCLUSIONS: Although the orchidometer remains valuable in assessing size of the individual testis, it is too insensitive to volume differentials relative to ultrasound to be used routinely to determine growth impairment. For this reason observation of an adolescent with varicocele should include an annual ultrasound assessment of testicular volume.

Adolescent↗
PubMed1999

The Talin head domain binds to integrin beta subunit cytoplasmic tails and regulates integrin activation.

The beta subunit cytoplasmic domains of integrin adhesion receptors are necessary for the connection of these receptors to the actin cytoskeleton. The cytoplasmic protein, talin, binds to beta integrin cytoplasmic tails and actin filaments, hence forming an integrin-cytoskeletal linkage. We used recombinant structural mimics of beta(1)A, beta(1)D and beta(3) integrin cytoplasmic tails to characterize integrin-binding sites within talin. Here we report that an integrin-binding site is localized within the N-terminal talin head domain. The binding of the talin head domain to integrin beta tails is specific in that it is abrogated by a single point mutation that disrupts integrin localization to talin-rich focal adhesions. Integrin-cytoskeletal interactions regulate integrin affinity for ligands (activation). Overexpression of a fragment of talin containing the head domain led to activation of integrin alpha(IIb)beta(3); activation was dependent on the presence of both the talin head domain and the integrin beta(3) cytoplasmic tail. The head domain of talin thus binds to integrins to form a link to the actin cytoskeleton and can thus regulate integrin function.

Amino Acid Sequence↗