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P J Ward

Publications and source records attributed to P J Ward.

At least 19 recordsLinked to original sources
PubMed2006

Modeling growth factor activity during proinflammatory stress: methodological considerations in assessing cytokine modulation of IGF binding proteins released by cultured bovine kidney epithelial cells.

The present research was conducted to model potential mechanisms through which IGFBPs might be affected by a key proinflammatory response initiating cytokine tumor necrosis factor (TNF-)-alpha. Madin-Darby bovine kidney epithelial (MDBK) cells, known to release IGFBPs in response to several stimuli, were grown under several conditions and challenged with forskolin (F) or recombinant TNF-alpha for 24h. Forskolin increased IGFBP-3 gene expression and media content of BP-3 protein. TNF-alpha increased basal and augmented F-mediated IGFBP-3 gene expression. However, TNF-alpha effects on the measurable media content of IGFBPs were influenced by culture conditions; in the absence of added protease inhibitors (PIs) or sufficient media albumin concentration (high BSA, 1mg/ml), the effect of TNF-alpha was to decrease (P<0.02) measurable IGFBPs. In the presence of PI and high BSA, media IGFBP-3 levels were shown to be increased by TNF-alpha consistent with the gene expression data. Changes in media IGFBP-3 protease activity were examined further to explain the observed effects of TNF-alpha on production and destruction of IGFBPs in media. When recombinant human IGFBP-3 (500 ng/ml) was added to PI-free, low BSA 100 microg/ml) media from TNF-treated MDBK cells, less than 10% of the BP-3 was recognizable by Western blot in 30 min; conversely, inclusion of High BSA and PI in media resulted in attenuation of the protease effect on the IGFBPs. The data suggest that the MDBK model of cellular response to proinflammatory stimulus is affected by culture conditions and that TNF-alpha affects media content of IGFBPs through effects on IGFBP gene expression coupled with degradation of IGFBPs via enhanced proteolytic enzyme release.

Animals↗
PubMed2001

Lipid peroxidation in hepatic steatosis in humans is associated with hepatic fibrosis and occurs predominately in acinar zone 3.

BACKGROUND AND AIMS: Hepatic steatosis has been shown to be associated with lipid peroxidation and hepatic fibrosis in a variety of liver diseases including non-alcoholic fatty liver disease. However, the lobular distribution of lipid peroxidation associated with hepatic steatosis, and the influence of hepatic iron stores on this are unknown. The aim of this study was to assess the distribution of lipid peroxidation in association with these factors, and the relationship of this to the fibrogenic cascade. METHODS: Liver biopsies from 39 patients with varying degrees of hepatic steatosis were assessed for evidence of lipid peroxidation (malondialdehyde adducts), hepatic iron, inflammation, fibrosis, hepatic stellate cell activation (alpha-smooth muscle actin and TGF-beta expression) and collagen type I synthesis (procollagen alpha1 (I) mRNA). RESULTS: Lipid peroxidation occurred in and adjacent to fat-laden hepatocytes and was maximal in acinar zone 3. Fibrosis was associated with steatosis (P < 0.04), lipid peroxidation (P < 0.05) and hepatic iron stores (P < 0.02). Multivariate logistic regression analysis confirmed the association between steatosis and lipid peroxidation within zone 3 hepatocytes (P < 0.05), while for hepatic iron, lipid peroxidation was seen within sinusoidal cells (P < 0.05), particularly in zone 1 (P < 0.02). Steatosis was also associated with acinar inflammation (P < 0.005). alpha-Smooth muscle actin expression was present in association with both lipid peroxidation and fibrosis. Although the effects of steatosis and iron on lipid peroxidation and fibrosis were additive, there was no evidence of a specific synergistic interaction between them. CONCLUSIONS: These observations support a model where steatosis exerts an effect on fibrosis through lipid peroxidation, particularly in zone 3 hepatocytes.

Actins↗
PubMed2000

Role of alcohol dehydrogenase 3 and cytochrome P-4502E1 genotypes in susceptibility to cancers of the upper aerodigestive tract.

Alcohol is a recognized risk factor for upper aerodigestive tract (UAT) cancers, but the mechanism by which alcohol causes cancer remains obscure. Ethanol is oxidized to acetaldehyde (the suspected carcinogenic agent in alcohol) by alcohol dehydrogenases (ADHs) and cytochrome P-4502E1 (CYP2E1), both of which exhibit great inter-individual variability in activity. The hypothesis that these polymorphisms influence susceptibility to alcohol-related cancers remains poorly documented. We investigated whether ADH(3) and CYP2E1 DraI and RsaI genotypes modified the risk of UAT cancers among 121 oral cavity/pharyngeal cancer patients, 129 laryngeal cancer patients, and 172 controls, all French Caucasians. Cancer risks and gene-alcohol interactions were analyzed by unconditional logistic regression, accounting for potential confounders. ADH(3) genotype was not associated with UAT cancer. In contrast, a 2-fold risk of oral cavity/pharyngeal (OR = 2.0, 95% CI 1.0-3.9) and laryngeal (OR = 1.8, 95% CI 1.0-3.5) cancers was observed for carriers of the CYP2E1 DraI C variant allele compared with other individuals. The risk associated with the CYP2E1 RsaI c2 variant allele also increased for oral cavity/pharyngeal cancer (OR = 2.6, 95% CI 1.0-6. 6). The effects of ADH(3) or CYP2E1 genotype and alcohol or tobacco were independent. The highest risk of oral cavity/pharyngeal cancer was observed among the heaviest drinkers (>80 g/day) with the CYP2E1 DraI C allele (OR = 5.8, 95% CI 1.9-18.2) or the CYP2E1 RsaI c2 allele (OR = 7.2, 95% CI 1.4-38.2) compared with lighter drinkers with other genotypes. Our study suggests that CYP2E1 genotype modifies the risk of UAT cancers, but due to the low frequency of CYP2E1 variant alleles, large-scale studies are needed to confirm our findings.

Alcohol Drinking↗
PubMed2000

FGF5 stimulates expansion of connective tissue fibroblasts and inhibits skeletal muscle development in the limb.

FGF5 is expressed in the mesenchyme and skeletal muscle of developing and adult mouse limbs. However, the function of FGF5 during development of the limb and limb musculature is unknown. To elucidate the inherent participation of FGF5 during limb organogenesis, a retroviral delivery system (RCAS) was used to overexpress human FGF5 throughout developing hind limb of chicken embryos. Misexpression of the soluble growth factor severely inhibited the formation of mature myocytes. Limbs infected with RCAS-FGF5 contained smaller presumptive muscle masses as evidenced by a decrease in MyoD and myosin heavy chain expressing cells. In contrast, ectopic expression of FGF5 significantly stimulated proliferation and expansion of the tenascin-expressing, connective-tissue fibroblast lineage throughout the developing limb. Histological analysis demonstrated that the increase in tenascin immunostaining surrounding the femur, ileum, and pubis in the FGF5 infected limbs corresponded to the fibroblasts forming the stacked-cell perichondrium. Furthermore, pulse labeling experiments with the thymidine analog, BrdU, revealed that the increased size of the perichondrium was attributable to enhanced cell proliferation. These results support a model whereby FGF5 acts as a mitogen to stimulate the proliferation of mesenchymal fibroblasts that contribute to the formation of connective tissues such as the perichondrium, and inhibits the development of differentiated skeletal muscle. These results also contend that FGF5 is a candidate mediator of the exclusive spatial patterning of the hind limb connective tissue and skeletal muscle.

Animals↗
PubMed1998

Overtaking road-accidents: differences in manoeuvre as a function of driver age.

Nine-hundred and seventy-three police road-accident files describing overtaking accidents were sampled from the headquarters of Nottinghamshire Constabulary, England, for the years 1989-1993. Salient facts were extracted from each case, including the exact manoeuvre involved, the principle explanatory factors, the driver(s) most at fault, and the drivers' ages. Two kinds of reliability measure for case interpretations. indicated high levels of consistency. Two induced exposure measures were used, comparing driver involvement in a given type of overtaking accident with involvement in overtaking accidents in general, and comparing the age profiles of the drivers most at fault with those of the other drivers involved. Ten types of overtaking accident were distinguished, and three are discussed in detail: collision with a right-turning vehicle (the most common injury-accident for overtakers), which tends to occur either because a young driver makes a faulty overtaking decision, or an older driver makes a faulty right turn; head-on collision, which affects all age groups roughly in proportion to exposure; and the 'return-and-lose-control' accident, which is associated particularly with young drivers. The study illustrates the 'structured judgement method' of accident causation research, in which human interpreters are used to ascribe causes and processes to individual cases, but orthodox research techniques are used to standardise procedures, and to assess and ensure reliability.

Accidents, Traffic↗
PubMed1998

Increased hepatic iron concentration in nonalcoholic steatohepatitis is associated with increased fibrosis.

BACKGROUND & AIMS: Nonalcoholic steatohepatitis (NASH) is a chronic liver disease that occasionally progresses to cirrhosis but usually has a benign course. The aim of this study was to investigate the role of the hemochromatosis mutation Cys282Tyr in development of the mild hepatic iron overload found in some patients with NASH and its association with hepatic damage in these patients. METHODS: Fifty-one patients with NASH were studied. The presence of the Cys282Tyr mutation was tested in all patients, and the data were analyzed with respect to the histological grade of steatosis, inflammation, Perls' staining, hepatic iron concentration (HIC), and serum iron indices. RESULTS: Thirty-one percent of patients with NASH were either homozygous or heterozygous for the Cys282Tyr mutation. This mutation was significantly associated with Perls' stain grade (P < 0.005), HIC (P < 0.005), and transferrin saturation percentage (P < 0.005) but not with serum ferritin levels. Linear regression analysis showed that increased hepatic iron (Perls' stain or HIC) had the greatest association with the severity of fibrosis (P < 0.0001). CONCLUSIONS: The Cys282Tyr mutation is responsible for most of the mild iron overload found in NASH and thus has a significant association with hepatic damage in these patients. Heterozygosity for the hemochromatosis gene mutation therefore cannot always be considered benign.

Adult↗
PubMed1998

The use of the supracondylar nail in the management of femoral fractures in the presence of other femoral implants in the very elderly.

In a retrospective study we review the use of the supracondylar nail for the treatment of distal femoral fractures above existing knee prostheses or below upper femoral implants in a very elderly population of mean age 85. Over a 2 year period we have used the Smith and Nephew supracondylar nail to stabilise seven distal third femoral fractures either distal to a femoral implant (six cases) or proximal to a total knee replacement. One patient died soon after surgery, one patient had an extension of the fracture proximal to the nail but the others made an excellent functional recovery with early mobilisation of the knee. We recommend the use of the supracondylar nail in the management of these difficult cases. The very elderly patient benefits from the early and stable fixation of these fractures.

Aged↗
PubMed1998

The progression of an infundibulum to aneurysm formation and rupture: case report and literature review.

OBJECTIVE AND IMPORTANCE: Infundibula (IFs) are funnel-shaped symmetrical enlargements that occur at the origins of cerebral arteries and are apparent on 7 to 25% of otherwise normal angiograms. They are frequently considered as normal anatomic variants of no pathogenic significance. CLINICAL PRESENTATION: We report the case of a ruptured posterior communicating artery aneurysm that had developed at the site of a previously known IF in a 49-year-old hypertensive woman. She had a poor conscious level at admission, with widespread subarachnoid hemorrhage and obstructive hydrocephalus. INTERVENTION: The patient was immediately ventilated, and an external ventricular drain was inserted. The aneurysm was successfully clipped; however, secondary hemorrhage occurred both before and during craniotomy. She developed marked hypernatremia and subsequently died. CONCLUSION: This is the 11th case of IF-to-aneurysm progression reported. It suggests that in certain cases, serial investigations may be indicated with IFs to detect aneurysm formation and preempt rupture.

Aneurysm, Ruptured↗
PubMed1998

The role of magnetic resonance imaging in the investigation of spinal dysraphism in the child with lower limb abnormality.

A review of magnetic resonance imaging (MRI) performed to exclude the presence of spinal dysraphism in children presenting with lower limb pathology is unrewarding in the absence of abnormal neurology. Over a 5-year period, 29 children ages 2 weeks to 15 years with a mean age of 6 years presenting with lower limb abnormalities were referred for MRI of the spine to exclude an occult neurologic cause for the deformities. More than one limb abnormality, for example pes cavus and limb length discrepancy, was present in 93% of the children, and 11 children had severe or recurrent talipes equinovarus deformity. Only two children (7%), both of whom had abnormal limb neurology, had abnormal MRI scans. In the absence of a demonstrable neurologic deficit in the lower limb, there appears to be no advantage in requesting MRI of the spine in children presenting with lower limb abnormality.

Child↗
PubMed1998

Tarsal tunnel syndrome: a study of the clinical and neurophysiological results of decompression.

The neurophysiological and clinical outcomes of surgical decompression of 22 cases of tarsal tunnel syndrome are analysed. Recent work by Pfeiffer & Cracchiolo has suggested a successful outcome in only 44% of cases. We have reviewed the outcome of surgery both clinically and with the use of nerve conduction studies. Pre- and post-operative motor conduction delays in the plantar nerves are compared with clinical results found both in the clinic and later by a postal questionnaire. Despite careful clinical and neurophysiological assessment prior to a full surgical release, only 42% of patients had a satisfactory outcome. A larger reduction in plantar nerve conduction delay post-operatively corresponded well to an improvement in symptoms. However, we were unable to predict which cases would respond to decompression using clinical or electrophysiological methods. We question the use of nerve conduction studies in the diagnosis of tarsal tunnel syndrome, and also the role of surgery in the management of this condition.

Decompression, Surgical↗
PubMed1997

Covariate effects on linkage and association using a general pair method.

The "general pair method" (GPM) is a nonparametric, identity-by-state (IBS) method of assessing linkage between a chromosomal marker and a binary phenotype. It is applicable to any pedigree structure, and uses marker information from affected as well as unaffected individuals. Results obtained here from nuclear families (Problem 2A) are contrasted with those from extended pedigrees (Problem 2B). Test statistics for chromosomal linkage between each marker and disease status are contrasted with tests for "direct association" which test the hypothesis that a particular allele is associated disease status across all pedigrees. A novel extension of the GPM is presented here for testing whether the strength of linkage (and/or association) depends on the levels of a covariate (i.e., dependency on gender, age, the levels of the "environmental factor," or the levels of the "quantitative phenotypes" supplied). The GPM is seen to have some power to detect major gene 1 on chromosome 5, and major gene 3 on chromosome 4. The gender interaction effects proved too small to detect. No direct associations are found.

Analysis of Variance↗
PubMed1997

Laryngeal and oropharyngeal cancer, and alcohol dehydrogenase 3 and glutathione S-transferase M1 polymorphisms.

In this study the GSTmu phenotype and ADH genotype at the ADH3 locus were investigated in a group of 39 alcoholic men with upper respiratory/digestive tract cancer: 21 with oropharyngeal cancer and 18 with laryngeal cancer. The results are compared with those of a control group of 37 alcoholic men without alcohol-related medical complications. Of the control subjects, 48% were found to be GSTmu deficient [GSTmu(-)] and 19% carried the ADH(3)1/ADH(3)1 genotype. In the laryngeal cancer patients, a significantly elevated frequency of both the GSTmu(-) (78%) and ADH(3)1/ADH(3)1 genotype (56%) was observed, relative to the control group. On the basis of this result, the risk of laryngeal cancer associated with the GSTmu(-) and ADH(3)1/ADH(3)1 genotypic combination within the population of alcoholics was estimated to be 12.9 with a 95% confidence interval of 1.8-92 (P < 0.01) relative to alcoholic individuals who have GSTmu [GSTmu(+)] and are not ADH(3)1/ADH(3)1. Thus, alcoholics who are GSTmu(-) and ADH(3)1/ADH(3)1 have at least an 80% greater risk of developing laryngeal cancer than alcoholics who are GSTmu(+) and who are not ADH(3)1/ADH(3)1. In addition, the oropharyngeal cancer patients had excess frequencies of both GSTmu(-) (62%) and ADH(3)1/ADH(3)1 (43%) relative to the control group, but these excess frequencies were not statistically significant. The GSTmu(-) and ADH(3)1/ADH(3)1 genotypic combination may be a constitutional risk factor for laryngeal cancer among alcoholics.

Adult↗
PubMed1997

Biochemistry and pharmacology of 7alpha-substituted androstenediones as aromatase inhibitors.

The inhibition of aromatase, the enzyme responsible for converting androgens to estrogens, is therapeutically useful for the endocrine treatment of hormone-dependent breast cancer. Research by our laboratory has focused on developing competitive and irreversible steroidal aromatase inhibitors, with an emphasis on synthesis and biochemistry of 7alpha-substituted androstenediones. Numerous 7alpha-thiosubstituted androst-4-ene-3,17-diones are potent competitive inhibitors, and several 1,4-diene analogs, such as 7alpha-(4'-aminophenylthio)-androsta-1,4-diene-3,17-di one (7alpha-APTADD), have demonstrated effective enzyme-activated irreversible inhibition of aromatase in microsomal enzyme assays. One focus of current research is to examine the effectiveness and biochemical pharmacology of 7alpha-APTADD in vivo. In the hormone-dependent 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary carcinoma model system, 7alpha-APTADD at a 50 mg/kg/day dose caused an initial decrease in mean tumor volume during the first week, and tumor volume remained unchanged throughout the remaining 5-week treatment period. This agent lowers serum estradiol levels and inhibits ovarian aromatase activity. A second research area has focused on the synthesis of more metabolically stable inhibitors by replacing the thioether linkage at the 7alpha position with a carbon-carbon linkage. Several 7alpha-arylaliphatic androst-4-ene-3,17-diones were synthesized by 1,6-conjugate additions of appropriate organocuprates to a protected androst-4,6-diene or by 1,4-conjugate additions to a seco-A-ring steroid intermediate. These compounds were all potent inhibitors of aromatase with apparent Kis ranging between 13 and 19 nM. Extension of the research on these 7alpha-arylaliphatic androgens includes the introduction of a C1-C2 double bond in the A-ring to provide enzyme-activated irreversible inhibitors. The desired 7alpha-arylaliphatic androsta-1,4-diene-3,17-diones were obtained from their corresponding 7alpha-arylaliphatic androst-4-ene-3,17-diones by oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). These inhibitors demonstrated enzyme-mediated inactivation of aromatase with apparent k(inact)s ranging from 4.4 x 10(-4) to 1.90 x 10(-3) s(-1). The best inactivator of the series was 7alpha-phenpropylandrosta-1,4-diene-3,17-dione, which exhibited a T(1/2) of 6.08 min. Aromatase inhibition was also observed in MCF-7 human mammary carcinoma cell cultures and in JAr human choriocarcinoma cell cultures, exhibiting IC50 values of 64-328 nM. The 7alpha-arylaliphatic androgens thus demonstrate potent inhibition of aromatase in both microsomal incubations and in choriocarcinoma cell lines expressing aromatase enzymatic activity. Additionally, the results from these studies provide further evidence for the presence of a hydrophobic binding pocket existing near the 7alpha-position of the steroid in the active site of aromatase. The size of the 7alpha-substituent influences optimal binding of steroidal inhibitors to the active site and affects the extent of enzyme-mediated inactivation observed with androsta-1,4-diene-3,17-dione analogs.

Androstenedione↗
PubMed1995

Measuring gene-disease association using a general pair method.

The general-pair-method (GPM) was applied to the analysis of the Problem 1 data set. GPM is a nonparametric, identity-by-state method for associating variation at a chromosomal locus with disease status. It can accommodate information from all pairs of individuals across any degree of genetic relatedness, including genetically unrelated individuals, within a single test statistic. Pairwise contrasts between members of different pedigrees, including "control" pedigrees containing no affected individuals, can therefore be exploited in order to increase the power of the test statistic. Such a strategy makes sense within the context of a candidate gene (direct association) study, where the alleles or genotypes of high disease risk are assumed to be the same ones within all families. Applied to the Problem 1 data set in this way, the GPM successfully identified the effect on disease status of locus 31 on chromosome 1, and of locus 23 on chromosome 5. The observed strength of gene-disease association at the other chromosomal loci was compatible with the null hypothesis.

Case-Control Studies↗
PubMed1993

Some developments on the affected-pedigree-member method of linkage analysis.

Some improvements are presented for the affected-pedigree-member method of linkage analysis, which is a generalization of the sib-pair method. The test statistic is extended to include contrasts between affected and unaffected pedigree members, so that it now utilizes marker information from all typed pedigree members rather than just the typed affected members. Computer simulation using a sample pedigree of 14 individuals shows that this modification can substantially increase statistical power where there is a direct association between marker variation and disease and where disease risk is elevated in carriers of the disease allele. Data on Huntington disease in 16 British families, which were analyzed previously using only the affected individuals, are reanalyzed with the unaffected individuals included. Strong rejection of the null hypothesis of no association between Huntington disease and the HindIII polymorphism is confirmed, but the particular families in which the association is significant differs from that obtained through an analysis based only on affected individuals and reflects more closely the results obtained from a lod-score analysis. The test statistic is also modified here to incorporate contrasts between individuals of zero kinship, if needed. This enables contrasts between individuals from different pedigrees, as well as contrasts involving individuals sampled from the general population, to be incorporated into the test of association. For population data, the methodology reduces to a type of contingency-table analysis, in which the rows of the table correspond to different marker-locus genotypes and in which the two columns categorize subjects into an "affected" group versus an "unaffected," or control, group. This aspect of the methodology is illustrated using two population data sets, the first relating APO-E genotype to the frequency of individuals undergoing maintenance hemodialysis and the second relating APO-B genotype to the frequency of coronary artery disease. The present methodology confirms the lack of association between marker and disease in the former data set and confirms the presence of association in the latter. Finally, the methodology is formulated here in terms of ordinary, multiperson kinship coefficients rather than in terms of the generalized kinship coefficients originally proposed. This greatly reduces the number of coefficients to be calculated, thereby enhancing the computational efficiency of the computer program.

Apolipoproteins B↗
PubMed1993

The freckle plot (daily turnaround time chart): a technique for timely and effective quality improvement of test turnaround times.

Test turnaround times are often monitored on a monthly basis. However, such an interval usually means that not all causes for delay in test reporting can be unequivocally identified for institution of remedial action. We have devised a daily chart--the freckle plot--that graphically displays the test turnaround times by laboratory receipt time. Different symbols are used to designate specimens reported within the test's turnaround time limit, those within 10 min beyond that limit, and those well outside the limit. These categories are adjustable to suit different limits of stringency. Freckle plots are produced on a daily basis and can be used to track down causes for test delays. Using the 1-h turnaround time "stat" potassium test as a model, we found 16 causes for test delay, of which 9 were potentially remediable. By applying these remedies, we were able to increase test compliance, in the day shift, from 91.5% (95% confidence interval 88.8%-93.7%) to 97.6% (95% confidence interval 96.4-98.55%), which is significant at P < 10(-7). This daily plot is a useful quality assurance tool, supplementing the more conventional tests used to ensure laboratory quality improvement.

Chemistry, Clinical↗