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2.
Alcohol Alcohol ; 50(4): 438-43, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25935157

ABSTRACT

AIM: To evaluate the effect on recurrent admission for alcohol-induced pancreatitis (that can be up to 48%) of a brief social work intervention for alcohol dependence in a single center in Ireland METHODS: Retrospective cohort study of patients admitted with acute alcohol-induced pancreatitis to a tertiary hospital in Ireland from January 2009 to December 2012. RESULTS: The relapse rate in the cohort of 160 patients with alcohol-induced pancreatitis was 28.1%. There was no difference in the relapse rate of those patients who received a social work intervention compared with those who did not (ANOVA, P = 0.229). The employment status was a significant risk factor for relapse (ANOVA, P = 0.027), but did not differ between those who did, and did not, receive the intervention. CONCLUSION: Although the cohort size did not allow great statistical power, it appears that our hospital's current social work intervention for alcohol-induced pancreatitis is ineffective in preventing relapse. Long-term prospective studies are required to formulate and better implement more efficacious interventions for such patients.


Subject(s)
Pancreatitis, Alcoholic/prevention & control , Social Work , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Ireland , Male , Middle Aged , Pancreatitis, Alcoholic/therapy , Recurrence , Retrospective Studies , Risk Factors , Young Adult
3.
QJM ; 108(12): 935-42, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25778110

ABSTRACT

BACKGROUND: Intensive care units (ICUs) exist to support patients through acute illness that threatens their life. Although ICUs aim to save life, they are also a place where a significant proportion of patients die with international mortality rates ranging from 15% to 24%. AIM: To explore the experience of relatives and staff of patients dying in ICU using qualitative approach. DESIGN: Consecutive patients were identified who were dying in the ICU. The researcher met the families prior to the patient's death. The ICU nurse and doctor most involved were interviewed within 48 h of the death. The families were interviewed 2 weeks later. Interviewees described their experience of the patient's dying and death. Recruitment until data saturation and thematic analysis occurred concurrently. RESULTS: Ten families, nurses and doctors were interviewed in relation to 10 patients. In caring for the patients who are dying in the ICU and their families, nurses practice to their satisfaction with creativity and autonomy, although concerned about continuity of care at handover. Families appreciate kindness and regular sensitive communication. Families would like more contact with the ICU doctors. Limiting access to the patient according to ICU protocol is distressing for relatives. Doctors struggle with decision making, determining prognosis and witnessing the grief of relatives. Some doctors wish to have a greater part in care of the dying patient. CONCLUSION: Distress among nurses reported in the ICU literature and attributed to disenfranchisement by doctors was not evident. In contrast, some doctors struggle to practice what they value. Adherence to ICU protocols needs flexibility when a patient is dying.


Subject(s)
Attitude to Death , Family/psychology , Intensive Care Units/standards , Medical Staff, Hospital/psychology , Nursing Staff, Hospital/psychology , Adult , Aged , Aged, 80 and over , Attitude of Health Personnel , Female , Health Services Research/methods , Humans , Interviews as Topic , Length of Stay/statistics & numerical data , Male , Middle Aged , New Zealand , Professional-Family Relations , Qualitative Research
4.
Curr Med Chem ; 21(4): 501-10, 2014.
Article in English | MEDLINE | ID: mdl-24251561

ABSTRACT

Intrinsic or acquired resistance to the HER2-targeted therapy trastuzumab is a clinical concern in the treatment of patients with HER2-over-expressing metastatic breast cancers. We demonstrate here that multiple models of intrinsic and acquired resistance exhibit increased phosphorylation of p38 MAPK. Kinase inhibition of p38 rescued trastuzumab sensitivity in cells with acquired resistance. In addition, knockdown of p38 increased sensitivity to trastuzumab in an intrinsically resistant cell line. We previously reported that expression of growth differentiation factor 15 (GDF15) is increased in trastuzumab-resistant HER2-overexpressing breast cancer cells. In this study, we found that exogenous GDF15 or stable overexpression of GDF15 stimulated p38 phosphorylation in HER2-positive cells, suggesting a possible mechanism by which p38 is activated in resistant cells.GDF15 stable clones showed significantly increased invasiveness, which was rescued by p38 kinase inhibition, suggesting that p38 plays a role in the pro-invasive phenotype conferred by GDF15. Importantly, immunohistochemical analysis of a breast tumor tissue array indicated a significant (p=0.0053) correlation between HER2 and phosphorylated p38 specifically in GDF15-positive tissues. Our results suggest that p38 signaling drives trastuzumab resistance and invasiveness in HER2-overexpressing breast cancer. Upstream growth factor signals that have previously been implicated in trastuzumab resistance, such as GDF15, may contribute to the increased phosphorylation of p38 found in resistant cells.


Subject(s)
Breast Neoplasms/drug therapy , Breast Neoplasms/enzymology , Receptor, ErbB-2/genetics , p38 Mitogen-Activated Protein Kinases/metabolism , Antibodies, Monoclonal, Humanized/administration & dosage , Antineoplastic Agents/administration & dosage , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Line, Tumor , Drug Resistance, Neoplasm , Female , Humans , Immunohistochemistry , Phosphorylation , Receptor, ErbB-2/biosynthesis , Receptor, ErbB-2/metabolism , Trastuzumab , p38 Mitogen-Activated Protein Kinases/genetics
5.
Vaccine ; 28(34): 5551-7, 2010 Aug 02.
Article in English | MEDLINE | ID: mdl-20600503

ABSTRACT

The liver fluke, Fasciola hepatica causes liver fluke disease, or fasciolosis, in ruminants such as cattle and sheep. An effective vaccine against the helminth parasite is essential to reduce our reliance on anthelmintics, particularly in light of frequent reports of resistance to some frontline drugs. In our study, Friesian cattle (13 per group) were vaccinated with recombinant F. hepatica cathepsin L1 protease (rFhCL1) formulated in mineral-oil based adjuvants, Montanide ISA 70VG and ISA 206VG. Following vaccination the animals were exposed to fluke-contaminated pastures for 13 weeks. At slaughter, there was a significant reduction in fluke burden of 48.2% in the cattle in both vaccinated groups, relative to the control non-vaccinated group, at p

Subject(s)
Antigens, Helminth/immunology , Cathepsins/immunology , Cattle Diseases/prevention & control , Fascioliasis/veterinary , Vaccines, Synthetic/immunology , Animals , Antibodies, Helminth/blood , Antibody Affinity , Arginase/metabolism , Cattle , Cattle Diseases/immunology , Cattle Diseases/parasitology , Fascioliasis/immunology , Fascioliasis/prevention & control , Immunoglobulin G/blood , Macrophages/immunology , Male , Recombinant Proteins/immunology
6.
Diabetologia ; 53(8): 1638-46, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20437026

ABSTRACT

AIMS/HYPOTHESIS: We examined whether retinal vessel diameter in persons with type 1 diabetes mellitus is associated with changes in subclinical anatomical and functional indicators of diabetic nephropathy. METHODS: Persons with type 1 diabetes mellitus had gradable fundus photographs and renal biopsy data at baseline and 5-year follow-up (n = 234). Retinal arteriolar and venular diameters were measured at baseline and follow-up. Central retinal arteriole equivalent (CRAE) and central retinal venule equivalent (CRVE) were computed. Baseline and 5-year follow-up renal structural variables were assessed by masked electron microscopic morphometric analyses from percutaneous renal biopsy specimens. Variables assessed included: mesangial fractional volume, glomerular basement membrane width, mesangial matrix fractional volume and glomerular basement membrane width composite glomerulopathy index. RESULTS: While controlling for other covariates, baseline CRAE was positively associated with change in the glomerulopathy index over the 5-year period. Change in CRAE was inversely related to a change in mesangial matrix fractional volume and abnormal mesangial matrix fractional volume, while change in CRVE was directly related to change in the volume fraction of cortex that was interstitium [Vv((Int/cortex))] over the 5-year period. Baseline CRAE or CRVE or changes in these diameters were not related to changes in other anatomical or functional renal endpoints. CONCLUSIONS/INTERPRETATION: Independently of other factors, baseline CRAE correlated with changes in glomerulopathy index, a composite measure of extracellular matrix accumulation in the mesangium and glomerular basement membrane. A narrowing of the CRAE was related to mesangial matrix accumulation. Changes in CRVE were related to changes in Vv((Int/cortex),) a measure of interstitial expansion in persons with type 1 diabetes mellitus.


Subject(s)
Diabetes Mellitus, Type 1/pathology , Diabetic Nephropathies/pathology , Retinal Vessels/pathology , Adolescent , Adult , Analysis of Variance , Diabetes Mellitus, Type 1/physiopathology , Diabetic Nephropathies/physiopathology , Double-Blind Method , Female , Humans , Kidney/pathology , Kidney/physiopathology , Logistic Models , Male , Middle Aged , Retinal Vessels/physiopathology
7.
Qual Saf Health Care ; 18(5): 355-9, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19812097

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) is the third-leading cause of cancer death for both men and women in the USA. Despite consensus recommendations for screening, just over half of eligible adults nationally have undergone screening. We therefore implemented a programme to improve the rate of CRC screening. METHODS: This study was conducted in the Utah Health Research Network and the University of Utah Community Clinics, a 100 000 patient, seven-practice, university-owned system offering primary and secondary care and ancillary services including endoscopy. We focused on patients aged >or=50 who were seen between 1 January 2003 and 31 October 2006, and who were not current for CRC screening at the time of the visit. The study included a three-phase INTERVENTION: electronic medical record (EMR) reminders, physician and medical assistant (MA) education about CRC screening guidelines, and redesign of patient visit workflow with an expanded role for MAs to review patients' CRC screening status and recommend testing when appropriate. With patient agreement, the MA entered a preliminary order in the EMR, and the physician confirmed or rejected the order. The primary outcome measure was the rate of screening colonoscopy ordered for eligible patients. RESULTS: The baseline colonoscopy referral rate was 6.0%. Provider education and electronic reminders had minimal immediate impact on screening rates. Addition of the expanded MA role was associated with a sustained increase in colonoscopy referral order rate to 13.4%, a relative improvement of 123%. CONCLUSIONS: The MA can play a key role in improving CRC screening rates as part of a redesigned system of primary care.


Subject(s)
Colonic Neoplasms/diagnosis , Mass Screening/statistics & numerical data , Patient Care Team/standards , Professional Role , Quality Assurance, Health Care/methods , Aged , Cancer Care Facilities , Clinical Competence/standards , Colonoscopy/statistics & numerical data , Female , Guideline Adherence , Humans , Male , Medical Records Systems, Computerized , Middle Aged , Pilot Projects , Process Assessment, Health Care , Reminder Systems , Utah
8.
Ir Med J ; 102(5): 143-6, 2009 May.
Article in English | MEDLINE | ID: mdl-19623809

ABSTRACT

This qualitative study is unique in examining the moment of death in a SPCU and in maximizing recall by interviewing relatives early in their bereavement. Despite its traditional significance, the moment of death has been largely unexplored in a hospice setting. Twenty-nine adults including 3 teenagers from 20 families were interviewed on average 22 days (range 8-42 days) after the death in a SPCU. They provided a rich and detailed description of the moment of death often with humour. Additional themes were the importance of vigil; qualities of the staff; value of ritual and prayer and the environment of the SPCU. We cannot hear the stories of the dead. We can try to hear the stories of those who have witnessed dying. These relatives cared deeply for the individual who was dying. They observe every detail, attending to their role and observing the role of others. They are valuable witnesses.


Subject(s)
Bereavement , Palliative Care/organization & administration , Attitude of Health Personnel , Attitude to Death , Decision Making , Humans , Ireland , Professional-Family Relations , Professional-Patient Relations , Qualitative Research
9.
J Renin Angiotensin Aldosterone Syst ; 2(4): 255-60, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11881132

ABSTRACT

Erythropoietin (Epo) is distinct amongst haematopoietic hormones, in that it is produced remote from the bone marrow. The tissue oxygen pressure required to trigger the Epo gene under physiological conditions is uniquely sited at a restricted area in the kidney termed the critmeter. Angiotensin II (Ang II) increases sodium reabsorption and hence oxygen consumption at any given bloodflow rate; therefore, it may affect the balance of renal oxygen supply vs. demand and hence Epo production. The purpose of this study was to determine whether Epo production is modulated by the renin-angiotensin system (RAS). Twenty normal subjects on a controlled sodium and protein diet had glomerular filtration rate (GFR) and renal plasma flow (RPF)assessed by standard methods of inulin and para-aminohippurate clearance, respectively, at baseline, hourly after the administration of losartan (25 mg) and after each 30 minute period of the infusion of Ang II at doses of 0.5, 1.5 and 2.5 ng/kg/minute. The baseline GFR was 115+/-4.0 ml/minute/1.73 m2, RPF 650+/-29 ml/minute/1.73 m2 and Epo 12.4+/-0.8 U/L. In spite of a marked increase in filtration fraction (FF) with Ang II, no changes in serum Epo levels were observed at two hours(11.7+/-1.3 U/L, p=n.s. compared with baseline). After the administration of losartan, there was a variable effect on FF, but a strong correlation of the change in serum Epo concentration and the change in FF(r=0.648, p=0.002), suggesting that the RAS may modulate Epo production.


Subject(s)
Antihypertensive Agents/administration & dosage , Erythropoietin/biosynthesis , Losartan/administration & dosage , Renin-Angiotensin System/drug effects , Renin-Angiotensin System/physiology , Adult , Angiotensin II/administration & dosage , Blood Pressure/drug effects , Female , Glomerular Filtration Rate , Humans , Male , Sodium/metabolism , Vasoconstrictor Agents/administration & dosage , Water-Electrolyte Balance/drug effects , Water-Electrolyte Balance/physiology
10.
Semin Oncol ; 27(1): 24-33, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10697019

ABSTRACT

The relief of physical and psychological symptoms is an essential part of palliative care. Advanced cancer is an acute process; because the clinical picture changes rapidly, symptoms must be reassessed regularly, and a careful history is essential. Defining the relationship of the symptoms to the disease can defuse fear and encourage a sense of control in patients and their families. We review the pathophysiology, causes, prevalence, consequence, and management of common symptoms in advanced cancer.


Subject(s)
Neoplasms/physiopathology , Neoplasms/therapy , Palliative Care , Disease Progression , Gastrointestinal Diseases/etiology , Gastrointestinal Diseases/therapy , Humans , Mental Disorders/etiology , Mental Disorders/therapy , Neoplasms/complications , Respiratory Tract Diseases/etiology , Respiratory Tract Diseases/therapy
11.
Am J Phys Anthropol ; 108(4): 507-29, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10229391

ABSTRACT

Tests for equal relative variation are valuable and frequently used tools for evaluating hypotheses about taxonomic heterogeneity in fossil hominids. In this study, Monte Carlo methods and simulated data are used to evaluate and compare 11 tests for equal relative variation. The tests evaluated include CV-based parametric bootstrap tests, modifications of Levene's test, and modified weighted scores tests. The results of these simulations show that a modified version of the weighted scores test developed by Fligner and Killeen ([1976] J. Am. Stat. Assoc. 71:210-213) is the only test that maintains an acceptable balance of type I and type II errors, even under conditions where all other tests have extraordinarily high type I error rates or little power.


Subject(s)
Fossils , Paleontology/methods , Animals , Hominidae , Humans , Monte Carlo Method
12.
Am J Phys Anthropol ; 107(3): 363-6, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9821499

ABSTRACT

Loth and Henneberg (1996, Am. J. Phys. Anthropol. 99:473-487) identified a single morphological feature of the mandible, the presence or absence of a distinct flexure or angulation of the posterior margin of the mandibular ramus at the level of the occlusal plane, which appears to be an extraordinarily accurate predictor of sex. Using only this feature, Loth and Henneberg were able to predict sex with 94% accuracy in a large sample of mandibles. In this article, we report the results of a blind test of mandibular ramus flexure as a predictor of sex. In our blind test, only 62.5% of the mandibles were correctly sexed, and virtually identical results were obtained when the same sample of mandibles was examined by a second observer. Overall, our results demonstrate that: 1) the association between ramus flexure and sex is weak; 2) the predictive accuracy of Loth and Henneberg's method is better than chance for only one sex, males; and 3) the method is based on a trait that cannot be reliably or consistently identified.


Subject(s)
Mandible/anatomy & histology , Sex Characteristics , Adult , Female , Forensic Anthropology/methods , Humans , Male , Reproducibility of Results
13.
Antimicrob Agents Chemother ; 42(7): 1819-30, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9661028

ABSTRACT

Candida dubliniensis is a recently described Candida species associated with oral candidosis in human immunodeficiency virus (HIV)-infected and AIDS patients, from whom fluconazole-resistant clinical isolates have been previously recovered. Furthermore, derivatives exhibiting a stable fluconazole-resistant phenotype have been readily generated in vitro from fluconazole-susceptible isolates following exposure to the drug. In this study, fluconazole-resistant isolates accumulated up to 80% less [3H] fluconazole than susceptible isolates and also exhibited reduced susceptibility to the metabolic inhibitors 4-nitroquinoline-N-oxide and methotrexate. These findings suggested that C. dubliniensis may encode multidrug transporters similar to those encoded by the C. albicans MDR1, CDR1, and CDR2 genes (CaMDR1, CaCDR1, and CaCDR2, respectively). A C. dubliniensis homolog of CaMDR1, termed CdMDR1, was cloned; its nucleotide sequence was found to be 92% identical to the corresponding CaMDR1 sequence, while the predicted CdMDR1 protein was found to be 96% identical to the corresponding CaMDR1 protein. By PCR, C. dubliniensis was also found to encode homologs of CDR1 and CDR2, termed CdCDR1 and CdCDR2, respectively. Expression of CdMDR1 in a fluconazole-susceptible delta pdr5 null mutant of Saccharomyces cerevisiae conferred a fluconazole-resistant phenotype and resulted in a 75% decrease in accumulation of [3H]fluconazole. Northern analysis of fluconazole-susceptible and -resistant isolates of C. dubliniensis revealed that fluconazole resistance was associated with increased expression of CdMDR1 mRNA. In contrast, most studies showed that overexpression of CaCDR1 was associated with fluconazole resistance in C. albicans. Increased levels of the CdMdr1p protein were also detected in fluconazole-resistant isolates. Similar results were obtained with fluconazole-resistant derivatives of C. dubliniensis generated in vitro, some of which also exhibited increased levels of CdCDR1 mRNA and CdCdr1p protein. These results demonstrate that C. dubliniensis encodes multidrug transporters which mediate fluconazole resistance in clinical isolates and which can be rapidly mobilized, at least in vitro, on exposure to fluconazole.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Antifungal Agents/pharmacology , Candida/drug effects , Candida/genetics , Drug Resistance, Multiple/genetics , Fluconazole/pharmacology , Membrane Transport Proteins , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , ATP-Binding Cassette Transporters/genetics , ATP-Binding Cassette Transporters/metabolism , Amino Acid Sequence , Antifungal Agents/metabolism , Base Sequence , Candida albicans/genetics , Drug Resistance, Microbial/genetics , Fluconazole/metabolism , Fungal Proteins/genetics , Gene Expression Regulation, Fungal , Humans , Microbial Sensitivity Tests , Molecular Sequence Data , Saccharomyces cerevisiae , Sequence Homology, Amino Acid
14.
Neuropathol Appl Neurobiol ; 23(3): 235-41, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9223133

ABSTRACT

Semliki Forest virus (SFV) infection of mice is used as a model to study pathogenic processes occurring in viral encephalitis and demyelinating disease. In this study, the long-term effects of infection by the avirulent M9 mutant of SPV on the central nervous system (CNS) of BALB/c and SJL mice were determined. The presence of infectious virus, viral RNA and cytokine mRNA in the brains of individual mice and the presence of lesions in the spinal cords of the same mice up to 360 days post-infection (d.p.i.) were analysed in order to detect any correlation between these parameters of pathogenesis. Infectious virus could not be detected beyond 7 d.p.i. for either mouse strain. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the presence of the E2 and nsP1 regions of the virus genome and mRNA for interferon-gamma and tumour necrosis factor-alpha. Viral RNA could be detected up to 90 d.p.i. for both mouse strains. Cytokine mRNA could be detected up to 28 d.p.i. for BALB/c mice but up to 360 d.p.i. for SJL mice. Inflammatory lesions, which were associated with cytokine mRNA expression, were not detected in BALB/c mice beyond 28 d.p.i. but were detected in two SJL mice at 90 d.p.i. It is concluded that M9-SFV infection induces long-term prolonged expression of pro-inflammatory cytokines in the CNS of the majority of SJL (but not BALB/c) mice which is not associated with persistence of the virus genome. M9-SFV infection of SJL mice may be a relevant model for the pathogenesis of multiple sclerosis in man.


Subject(s)
Alphavirus Infections/physiopathology , Semliki forest virus , Alphavirus Infections/pathology , Animals , Central Nervous System/virology , Cytokines/genetics , Mice , Mice, Inbred BALB C , Mice, Inbred Strains , Polymerase Chain Reaction , RNA, Viral/analysis , Semliki forest virus/genetics , Semliki forest virus/isolation & purification , Spinal Cord/pathology , Time Factors , Transcription, Genetic
15.
Am J Kidney Dis ; 28(1): 62-6, 1996 Jul.
Article in English | MEDLINE | ID: mdl-8712223

ABSTRACT

In light of the growing understanding of the toxic effects of glycated albumin and of the preferential excretion of this substance, the excretion of glycated albumin could be considered a physiologic function of the kidney. Furthermore, if the increased load of glycated albumin in diabetic patients results in glycated albumin excretion rates in the range of 20 to 200 microg/min, might this not be considered "physiologic microalbuminuria"? The hypothesis is presented that microalbuminuria composed of glycated albumin is a homeostatic renal function. Although some proteins are glycosylated for their normal physiologic function, many proteins are glycated nonenzymatically according to ambient blood glucose. Albumin is subject to nonenzymatic glycation in all humans, but at increased rates in diabetic patients. Glycated albumin induces changes in the microvasculature and glomerulus that may lead to endothelial dysfunction and diabetic nephropathy, respectively. Renal excretion of glycated albumin is enhanced compared with native albumin. To explore this potential homeostatic function of the kidney, patients with impaired renal function were studied to determine whether glycated albumin accumulates. Plasma levels of glycated albumin were determined in diabetic and nondiabetic patients on hemodialysis. Hemoglobin A1c was used as an index of the rate of nonenzymatic glycation of proteins. Hemoglobin A1c was increased in the diabetic subjects but was normal in the nondiabetic group (7.9% +/- 0.5% v 6.2% +/- 0.2%, respectively; P < 0.01). On the other hand, the glycated albumin was elevated in both groups and was not significantly different between them (1.95% +/- 0.15% in the diabetic patients v 1.75% +/- 0.14% in the nondiabetic patients; P = NS). The results of this study provide the first clinical evidence supporting the hypothesis that the excretion of glycated albumin is a homeostatic renal function.


Subject(s)
Albuminuria/etiology , Diabetic Nephropathies/metabolism , Kidney Failure, Chronic/metabolism , Serum Albumin/metabolism , Aged , Albuminuria/physiopathology , Case-Control Studies , Diabetes Mellitus, Type 2/complications , Diabetic Nephropathies/physiopathology , Diabetic Nephropathies/therapy , Female , Glycation End Products, Advanced , Glycosylation , Homeostasis , Humans , Kidney/physiopathology , Kidney Failure, Chronic/physiopathology , Kidney Failure, Chronic/therapy , Male , Middle Aged , Renal Dialysis , Glycated Serum Albumin
16.
J Magn Reson Imaging ; 6(3): 437-44, 1996.
Article in English | MEDLINE | ID: mdl-8724408

ABSTRACT

We study how classification accuracy can be improved when both different data preprocessing methods and computerized consensus diagnosis (CCD) are applied to 1H magnetic resonance (MR) spectra of astrocytomas, meningiomas, and epileptic brain tissue. The MR spectra (360 MHz, 37 degrees C) of tissue specimens (biopsies) from subjects with meningiomas (95; 26 cases), astrocytomas (74; 26 cases), and epilepsy (37; 8 cases) were preprocessed by several methods. Each data set was partitioned into training and validation sets. Robust classification was carried out via linear discriminant analysis (LDA), artificial neural nets (NN), and CCD, and the results were compared with histopathological diagnosis of the MR specimens. Normalization of the relevant spectral regions affects classification accuracy significantly. The spectra-based average three-class classification accuracies of LDA and NN increased from 81.7% (unnormalized data sets) to 89.9% (normalized). CCD increased the classification accuracy of the normalized sets to an average of 91.8%. CCD invariably decreases the fraction of unclassifiable spectra. The same trends prevail, with improved results, for case-based classification. Preprocessing the 1H MR spectra is essential for accurate and reliable classification of astrocytomas, meningiomas, and nontumorous epileptic brain tissue. CCD improves classification accuracy, with an attendant decrease in the fraction of unclassifiable spectra or cases.


Subject(s)
Brain Neoplasms/diagnosis , Image Processing, Computer-Assisted/instrumentation , Magnetic Resonance Imaging/instrumentation , Magnetic Resonance Spectroscopy/instrumentation , Astrocytoma/classification , Astrocytoma/diagnosis , Astrocytoma/pathology , Biopsy , Brain/pathology , Brain Neoplasms/classification , Brain Neoplasms/pathology , Epilepsy/classification , Epilepsy/diagnosis , Epilepsy/pathology , Humans , Meningeal Neoplasms/classification , Meningeal Neoplasms/diagnosis , Meningeal Neoplasms/pathology , Meningioma/classification , Meningioma/diagnosis , Meningioma/pathology , Neural Networks, Computer , Sensitivity and Specificity
17.
Anticancer Res ; 16(3B): 1485-9, 1996.
Article in English | MEDLINE | ID: mdl-8694517

ABSTRACT

Multiple samples from 42 astrocytomas were investigated ex vivo by 1H MR spectroscopy followed by histological assessment. MR visible lipids were detected in 27 of 32 grade 4 astrocytomas. These lipids were heterogeneously distributed within the tumours. Their amount correlated positively with the amount of histologically detected necrosis. Mobile lipids were also observed in grade 4 astrocytoma samples without necrosis, as well as in one of three grade 3, two of three grade 2 and two of four grade 1 astrocytomas. The clinical significance of MR visible lipids, their cellular location, and their possible biological bases are discussed.


Subject(s)
Astrocytoma/metabolism , Lipid Metabolism , Astrocytoma/pathology , Humans , Magnetic Resonance Spectroscopy , Necrosis
18.
Biochem Cell Biol ; 74(3): 355-62, 1996.
Article in English | MEDLINE | ID: mdl-8883841

ABSTRACT

Hyperglycemia is of central importance in the pathogenesis of the complications of diabetes mellitus. Glucose activation of the polyol pathway may lead to renal arteriolar smooth muscle and glomerular mesangial cell hypocontractility. In the streptozotocin-induced diabetic rat, the effect of the aldose reductase inhibitor, tolrestat, in preventing glomerular hyperfiltration, renal hypertrophy, extracellular matrix accumulation, and mesangial cell hypocontractility was addressed. Streptozotocin-induced diabetic rats were followed for 12 weeks and half received tolrestat (25 mg/kg per day). Increased glomerular filtration rate was prevented by tolrestat (3.1 +/- 0.3 vs. 1.8 +/- 0.2 mL/min, diabetes vs. diabetes + tolrestat, p < 0.01), in part by reduction of the filtration fraction (0.39 +/- 0.03 vs. 0.29 +/- 0.01, diabetes vs. diabetes + tolrestat, p < 0.01). Tolrestat prevented the raised albumin excretion rates (3594 +/- 1154 vs. 713 +/- 161 mg/24 h, diabetes vs. diabetes + tolrestat, p < 0.01). Endothelin-1-induced contraction of isolated glomeruli was normal in tolrestat-treated diabetic animals compared with the hypocontractile diabetic glomeruli. Tolrestat prevented glomerular hypertrophy (1.86 +/- 0.10 vs. 1.49 +/- 0.03 microns 2 x 10(5), diabetes vs. diabetes + tolrestat, p < 0.001) and attenuated the accumulation of basement-membrane-like material (50.2 +/- 0.4% vs. 46.4 +/- 0.8%, diabetes vs. diabetes+tolrestat, p < 0.001). Fractional mesangial expansion was unchanged in tolrestat-treated diabetic rats compared with untreated animals. Tolrestat prevents the functional changes of glomerular hyperfiltration, mesangial cell hypocontractility, and increased glomerular permeability to albumin. Polyol accumulation may have differential effects on glomerular growth and extracellular matrix accumulation in early diabetic nephropathy.


Subject(s)
Diabetes Mellitus, Experimental/pathology , Diabetic Nephropathies/prevention & control , Kidney Glomerulus/pathology , Naphthalenes/therapeutic use , Ampholyte Mixtures/metabolism , Animals , Diabetes Mellitus, Experimental/complications , Kidney Glomerulus/drug effects , Male , Polymers/metabolism , Rats , Rats, Sprague-Dawley , Sciatic Nerve/metabolism
19.
20.
NMR Biomed ; 7(4): 172-80, 1994 Jun.
Article in English | MEDLINE | ID: mdl-7946995

ABSTRACT

To examine metabolic heterogeneity in primary brain tumour, multiple biopsies (one to five per tumour) from four benign meningiomas, five acoustic schwannomas, eleven glial tumours and five medulloblastomas were each subdivided into one to five samples (total = 194) and investigated using ex vivo 360 MHz 1H MR spectroscopy with histopathological correlation. Low amounts of mobile lipids were detected in meningothelial meningiomas and medulloblastomas, high amounts in some or all samples of all other tumours. The differences in non-lipid metabolites between different tumour types were less marked, with the exception of the medulloblastomas, which had high amounts of N-acetyl aspartate and cholines. The amount of mobile lipid correlated with Antoni type B areas in schwannomas and necrosis in a high grade giant cell tumour. The amount of lipid varied significantly from sample to sample in a grade 2 astrocytoma and grade 4 astrocytoma samples with 0-5% necrosis but did not correlate with the site in the tumour or histopathological characteristics. The metabolic heterogeneity occurred on a spatial scale at least as small as the size of the MR samples, i.e., < or = 60 mg. These results suggest that the detection of metabolic heterogeneity and mobile lipids may have importance for the design of clinical studies.


Subject(s)
Brain Neoplasms/metabolism , Lipid Metabolism , Astrocytoma/metabolism , Astrocytoma/pathology , Biopsy , Brain/metabolism , Brain/pathology , Brain Neoplasms/pathology , Humans , Magnetic Resonance Spectroscopy/methods , Medulloblastoma/metabolism , Medulloblastoma/pathology , Meningioma/metabolism , Meningioma/pathology , Neuroglia/pathology , Neuroma, Acoustic/metabolism , Neuroma, Acoustic/pathology , Protons , Seizures/metabolism , Seizures/pathology
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