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Biomedical subjects

M Martin

Publications and source records attributed to M Martin.

At least 163 records · Page 9Linked to original sources

Interleukin-1 polymorphisms associated with increased risk of gastric cancer.

Helicobacter pylori infection is associated with a variety of clinical outcomes including gastric cancer and duodenal ulcer disease. The reasons for this variation are not clear, but the gastric physiological response is influenced by the severity and anatomical distribution of gastritis induced by H. pylori. Thus, individuals with gastritis predominantly localized to the antrum retain normal (or even high) acid secretion, whereas individuals with extensive corpus gastritis develop hypochlorhydria and gastric atrophy, which are presumptive precursors of gastric cancer. Here we report that interleukin-1 gene cluster polymorphisms suspected of enhancing production of interleukin-1-beta are associated with an increased risk of both hypochlorhydria induced by H. pylori and gastric cancer. Two of these polymorphism are in near-complete linkage disequilibrium and one is a TATA-box polymorphism that markedly affects DNA-protein interactions in vitro. The association with disease may be explained by the biological properties of interleukin-1-beta, which is an important pro-inflammatory cytokine and a powerful inhibitor of gastric acid secretion. Host genetic factors that affect interleukin-1-beta may determine why some individuals infected with H. pylori develop gastric cancer while others do not.

Alleles↗

Role of tumor cell apoptosis in tumor antigen migration to the draining lymph nodes.

Establishment of an immune response against cancer may depend on the capacity of dendritic cells to transfer tumor Ags into T cell-rich areas. To check this possibility, we used a colon cancer cell variant that yields tumors undergoing complete T cell-dependent rejection when injected into syngeneic rats. We previously demonstrated that immunogenicity of these tumors depended on the early apoptosis of a part of these tumor cells. In this paper we show that fluorescent tumor cell proteins are released from FITC-labeled tumor cells and undergo engulfment by tumor-infiltrating monocytes without a phenotype of mature dendritic cells or macrophages. Fluorescence-labeled mononuclear cells with a phenotype of MHC class II+ dendritic cells are also found in the T cell areas of the draining lymph nodes. Interestingly, no fluorescent cell can be found in lymph nodes after a s.c. injection of Bcl2-transfected apoptosis-resistant tumor cells that yielded progressive tumors. Proliferation of tumor-immune T lymphocytes was induced by dendritic cells isolated from the draining lymph nodes recovered after a s.c. injection of apoptosis-sensitive, but not apoptosis-resistant, tumor cells. These results show that tumor cell apoptosis releases proteins that are engulfed by inflammatory cells in the tumor, then transported to lymph node T cell areas where they can induce a specific immune response leading to tumor rejection.

Adenocarcinoma↗

Reduction of azides to amines mediated by tin bis(1,2-benzenedithiolate)

[reaction: see text] A procedure for the conversion of azides to amines, which uses NaBH4 and catalytic amounts of tin(IV) 1,2-benzenedithiolate, is disclosed. Primary, secondary, tertiary, aromatic, and heteroaromatic azides are reduced in excellent yields under very mild conditions.

Journal Article↗

Treatment of poor-prognosis early rheumatoid arthritis. A randomized study of treatment with methotrexate, cyclosporin A, and intraarticular corticosteroids compared with sulfasalazine alone.

OBJECTIVE: To determine whether a regimen of methotrexate, cyclosporin A, and corticosteroids introduced at onset in poor-prognosis rheumatoid arthritis (RA) can produce a significant improvement in outcome compared with standard monotherapy with sulfasalazine (SSZ). METHODS: Eighty-two consecutive patients presenting with new, untreated RA of less than 12 months' duration who fulfilled criteria for poor long-term outcome were randomized to receive either combination therapy (n = 40) or SSZ alone (n = 42). The primary outcome measures were remission and American College of Rheumatology (ACR) criteria for 20% improvement at 48 weeks. RESULTS: After 48 weeks, the numbers of patients who met the ACR criteria for 20% improvement were not significantly different between the two groups (combination 58% versus SSZ 45%), and similar numbers of patients had persisting clinical remission (approximately 10% both groups). During the first 3 months, there were significantly greater reductions in parameters of disease activity in the combination group. By 24 weeks, the swollen and tender joint counts, C-reactive protein levels, and erythrocyte sedimentation rates had fallen significantly in both groups, with a greater improvement in the swollen and tender joint count in the combination group. At 48 weeks, the radiographic damage score had increased by a median of 1 (range 0-42.5) in the combination group and 1.25 (range 0-72.5) in the SSZ group (P = 0.28; although there were significant differences in the scores for the right hand). There were significantly fewer withdrawals due to lack of efficacy in the combination group than in the SSZ group (1 of 40 versus 10 of 42; P = 0.007). In the combination group, dose reduction was needed in 22.5% because of hypertension and in 22.5% because of elevated creatinine levels. Over 48 weeks, serum creatinine increased in both groups, but particularly in the combination arm. CONCLUSION: In poor-prognosis RA patients, "aggressive" combination therapy led to more rapid disease suppression but did not result in significantly better ACR response or remission rates. This suggests that in poor-prognosis disease, an approach based on identifying patients with poor treatment responses before extra therapy is added ("step-up" approach) may be more appropriate than the use of combination therapy in all patients from the outset.

Adrenal Cortex Hormones↗

Subclavian Vein Thrombosis.

A review is presented of the pathogenesis, treatment option, and long term outcome of subclavian vein thrombosis.

Journal Article↗

Predictive Factors for the Removal of "Soft" Femoropopliteal Occlusions with Intraarterial Short-term and High-Dose Urokinase Treatment.

To date, intraarterial lysis is a widely accepted form of treatment for femoropopliteal occlusions. However, the outcome of therapy has been difficult to predict. Therefore, the present study dealt with two parameters likely to influence the occlusion removal rate. These are the outflow condition distal of the occlusion, and the occlusion length. Fifty patients with subacute femoropopliteal occlusions were treated with intraarterial thrombolysis and, in case residual obstructions were left, with subsequent catheter dilation. Only "soft" occlusions that were probed by a guide wire and proved to be penetrable were chosen for treatment. The occlusion age was 3.79 +/- 4.57 weeks with 90% of cases in the range of 1 day to 6 weeks. Fibrinolytic therapy consisted of one to three one-hour series of 300,000 IU urokinase instillation directly into the occlusion material. The complete clearance rate was 34/50 = 68%. In successfully treated patients, both the pressure gradient (difference between systemic and ankle pressure) and the walking distance improved significantly. Most important factors for success or failure of treatment were the quality of calf outflow and the length of obstruction. Thus, patients with at least one calf artery open and an occlusion length of under 10 cm presented with an opening rate of 88.5%, whereas patients with no calf arteries patent and an occlusion length over 20 cm presented with an opening rate of only 20%. The age of the occlusions, all penetrable by a guide wire prior to treatment, did not influence the rate of recanalization. Intraarterial short-term and high-dose urokinase infusion is an excellent form of treatment for subacute femoropopliteal occlusions. Especially good results with a 88.5% clearance rate were achieved in patients who presented with at least one calf artery open and an occlusion length below 10 cm.

Journal Article↗

Cognitive functions and psychopathological symptoms in early-onset schizophrenia.

Type and extent of objectively tested cognitive impairments (attention, verbal fluency, nonverbal reasoning) and their association with self-ratings (Paranoia Depression Scale; Frankfurt Complaint Questionnaire) and clinical assessments (Brief Psychiatric Rating Scale, Scales for the Assessment of Positive Symptoms and Negative Symptoms) of psychopathological symptoms were studied in a sample of 74 adolescents primarily suffering from chronic schizophrenia (DSM-III-R; mean duration of illness = 3.4 years), including 15 patients with a very early onset (< 14 years). Special consideration was given to the differentiation between positive and negative symptoms. In cross-sectional analyses, the schizophrenic adolescents were remarkably impaired in both cognitive functions (attention, reasoning) and psychopathological measures (BPRS, SANS, SAPS). However, factor analysis yielded orthogonal factors for cognitive and psychopathological parameters, and canonical correlation analyses did not find a significant correlation between these two areas. As the degree of objectively measured cognitive impairment in chronic schizophrenic adolescents cannot be predicted by the severity of individual psychopathological symptoms, a multidimensional evaluation of the symptomatology seems to be appropriate. Moreover, premorbid disturbances (motor and/or language developmental disorders) and onset characteristics (age, pattern, subdiagnosis), and their relationship to cognitive impairments were investigated. Premorbid disturbances were confirmed as risk factors for the subsequent occurrence of cognitive impairments.

Adolescent↗

[Inframalleolar bypass in limb salvage. Late results].

STUDY OBJECTIVE: The objective of this retrospective study was to report the long-term results of distal revascularization at the ankle in patients with critical ischemia. PATIENTS AND METHODS: From January 1989 to November 1999, 50 inframalleolar bypasses were performed in 49 patients (35 males and 14 females with a mean age of 75 years [range: 51 to 95 years]). Twenty-five patients (50%) were diabetics. All patients presented with critical ischemia of the lower limb. Distal anastomosis was performed at the retromalleolar posterior tibial artery in 28 cases (56%), pedal artery in 20 cases (40%) and distal fibular artery in two cases (4%). Bypasses were performed using a greater saphenous vein (n = 38), a cryopreserved arterial allograft (n = 9), or a PTFE graft (n = 2). A composite graft with greater saphenous vein and arterial allograft was performed in two cases. RESULTS: There were two early postoperative deaths. One patient presented a blow-out of the distal anastomosis that required bypass ligation and subsequent leg amputation. Early thrombosis of the graft occurred in four cases, leading to major amputation in three cases. No patients were lost to follow-up and mean follow-up was 26.7 months (range: 1 to 86 months). Graft thrombosis occurred in 15 patients and led to amputation in 6 cases. Bypass graft patency rate was 72% and 61% at 1 year and 3 years, respectively, yielding a 80% limb salvage rate at 3 years. The 3-year actuarial survival rate was 53%. CONCLUSION: Inframalleolar bypasses are a valuable tool in patients with critical ischemia. The lower limb salvage rate is satisfactory in this elderly population. Based on this experience, angiography with good run-off and, when necessary, a surgical approach to verify patency of the arteries at the ankle should always be performed before undertaking a major amputation.

Aged↗

Validation of the United States' version of the World Health Organization Quality of Life (WHOQOL) instrument.

In 1991, the World Health Organization initiated a project to simultaneously develop a quality of life (QOL) instrument in 15 countries: The World Health Organization Quality of Life (WHOQOL) instrument. This was intended as a generic QOL tool for use with patients across varying disease types, severities of illness, and cultural subgroups. The objective of the current study was to evaluate the WHOQOL-100 in the U.S., one of the original 15 participating countries. The WHOQOL is a 100-item self-report instrument consisting of 24 subscales within six domains: Physical, Psychological, Independence, Social, Environment, and Spiritual. Four additional items pertain to overall QOL/health. We tested the WHOQOL-100 (U.S. version) in a sample of 443 adults (n = 251 chronically ill, n = 128 healthy, and n = 64 childbearing) in the U.S. to test its reliability (internal consistency, test-retest), construct validity (convergent, discriminant), responsiveness, and factor structure. The WHOQOL-100 (U.S. version) has acceptable internal consistency (alpha range: 0.82-0.95 across domains) and reproducibility (ICC range: 0.83-0.96 at 2-week retest interval). It is responsive to change in clinical conditions, as evidenced by predicted score change (effect size) in women after childbirth. Construct validity was demonstrated by (1) its correlation with the Short Form-36 and Subjective Quality of Life Profile, and (2) its ability to discriminate between the diverse samples in this study. The conceptual structure was confirmed exactly with the exception of four facets that did not correlate most highly with the domains to which they were originally assigned, but these differences were minor. The WHOQOL measurement system is suitable for evaluating the QOL of adults in the U.S. The psychometric properties will be continually evaluated as more data become available in the U.S.

Adult↗

A note on Corballis (1997) and the genetics and evolution of handedness: developing a unified distributional model from the sex-chromosomes gene hypothesis.

A unified, quantitative model for sex, twin, parent, and grandparent influences on handedness is presented. Recent research modeling the evolutionary development of genetic mechanisms for the transmission of handedness on the basis of genotype fitness has appeared to lead to the conclusion that a handedness gene cannot be located on the sex chromosomes. It is shown in this article, however, that this conclusion is not of general validity. The sex-chromosomes hypothesis is developed further, and it is demonstrated that a wide-ranging, detailed, and parsimonious account of the distribution of handedness is obtained when left-handedness is assumed to be associated recessively, and with low penetrance, with genetic variation located on the X chromosome.

Female↗

Mice deficient for delta- and mu-opioid receptors exhibit opposing alterations of emotional responses.

The role of the opioid system in controlling pain, reward and addiction is well established, but its role in regulating other emotional responses is poorly documented in pharmacology. The mu-, delta- and kappa- opioid receptors (encoded by Oprm, Oprd1 and Oprk1, respectively) mediate the biological activity of opioids. We have generated Oprd1-deficient mice and compared the behavioural responses of mice lacking Oprd1, Oprm (ref. 6) and Oprk1 (ref. 7) in several models of anxiety and depression. Our data show no detectable phenotype in Oprk1-/- mutants, suggesting that kappa-receptors do not have a role in this aspect of opioid function; opposing phenotypes in Oprm-/- and Oprd1-/- mutants which contrasts with the classical notion of similar activities of mu- and delta-receptors; and consistent anxiogenic- and depressive-like responses in Oprd1-/- mice, indicating that delta-receptor activity contributes to improvement of mood states. We conclude that the Oprd1-encoded receptor, which has been proposed to be a promising target for the clinical management of pain, should also be considered in the treatment of drug addiction and other mood-related disorders.

Animals↗

Cocaine, but not morphine, induces conditioned place preference and sensitization to locomotor responses in CB1 knockout mice.

The involvement of cannabinoid CB1 receptors in morphine and cocaine motivational effects was investigated using CB1 knockout mice. For this purpose, we evaluated the rewarding effects in the place conditioning paradigm and the sensitization to the locomotor responses induced by these drugs. The hyperlocomotion induced by acute morphine administration (15 mg/kg, s.c.) was preserved, but the sensitization to this locomotor response induced by chronic morphine treatment was abolished in CB1 mutant mice. Morphine (5 mg/kg, s.c.) induced conditioned place preference in wild-type mice but failed to produce any response in knockout mice, indicating the inability of morphine to induce rewarding effects in the absence of CB1 cannabinoid receptors. When the aversive effects of morphine withdrawal were investigated using the place aversion paradigm, no differences between genotypes were observed. Acute cocaine (10 mg/kg, i.p.) induced hyperlocomotor responses in wild-type and knockout mice and a chronic cocaine treatment produced a similar sensitization to this response in both genotypes. In the conditioning place preference paradigm, cocaine (20 mg/kg, i.p.) produced rewarding responses in both wild-type and knockout mice. These results demonstrate that CB1 receptors are essential for adaptive responses produced by chronic morphine but not by chronic cocaine treatment.

Animals↗

Analysis of variance for gene expression microarray data.

Spotted cDNA microarrays are emerging as a powerful and cost-effective tool for large-scale analysis of gene expression. Microarrays can be used to measure the relative quantities of specific mRNAs in two or more tissue samples for thousands of genes simultaneously. While the power of this technology has been recognized, many open questions remain about appropriate analysis of microarray data. One question is how to make valid estimates of the relative expression for genes that are not biased by ancillary sources of variation. Recognizing that there is inherent "noise" in microarray data, how does one estimate the error variation associated with an estimated change in expression, i.e., how does one construct the error bars? We demonstrate that ANOVA methods can be used to normalize microarray data and provide estimates of changes in gene expression that are corrected for potential confounding effects. This approach establishes a framework for the general analysis and interpretation of microarray data.

Female↗

Discrimination of sepsis and systemic inflammatory response syndrome by determination of circulating plasma concentrations of procalcitonin, protein complement 3a, and interleukin-6.

OBJECTIVE: To evaluate whether plasma concentrations of procalcitonin (PCT), interleukin-6 (IL-6), protein complement 3a (C3a), leukocyte elastase (elastase), and the C-reactive protein (CRP) determined directly after the clinical onset of sepsis or systemic inflammatory response syndrome (SIRS) discriminate between patients suffering from sepsis or SIRS and predict the outcome of these patients. DESIGN: Prospective study. SETTING: Medical intensive care unit at a university hospital. PATIENTS: Twenty-two patients with sepsis and 11 patients with SIRS. MEASUREMENTS AND MAIN RESULTS: The plasma concentrations of PCT, C3a, and IL-6 obtained < or =8 hrs after clinical onset of sepsis or SIRS but not those of elastase or CRP were significantly higher in septic patients (PCT: median, 16.8 ng/mL, range, 0.9-351.2 ng/mL, p = .003; C3a: median, 807 ng/mL, range, 422-4788 ng/mL, p < .001; IL-6: median, 382 pg/mL, range, 5-1004 pg/mL, p = .009, all Mann-Whitney rank sum test) compared with patients suffering from SIRS (PCT: median, 3.0 ng/mL, range, 0.7-29.5 ng/mL; C3a: median, 409 ng/mL, range, 279566 ng/mL; IL-6: median, 98 pg/mL, range, 23-586 pg/mL). The power of PCT, C3a, and IL-6 to discriminate between septic and SIRS patients was determined in a receiver operating characteristic analysis. C3a was the best variable to differentiate between both populations with a maximal sensitivity of 86% and a specificity of 80%. An even better discrimination (i.e., a maximal sensitivity of 91% and a specificity of 80%) was achieved when PCT and C3a were combined in a "sepsis score." C3a concentrations also helped to predict the outcome of patients. Based on the sepsis score, a logistic regression model was developed that allows a convenient and reliable determination of the probability of an individual patient to suffer from sepsis or SIRS. CONCLUSIONS: Our data show that the determination of PCT, IL-6, and C3a is more reliable to differentiate between septic and SIRS patients than the variables CRP and elastase, routinely used at the intensive care unit. The determination of PCT and C3a plasma concentrations appears to be helpful for an early assessment of septic and SIRS patients in intensive care.

Adult↗

Progression of aortic stenosis in the boxer.

Thirty-five boxers that had been referred to the Royal (Dick) School of Veterinary Studies between 1989 and 1994 with left heart base murmurs and aortic velocities greater than 1.5 m/second on Doppler echocardiography were recalled for clinical examination and Doppler echocardiography between 1995 and 1996. Five dogs (14 per cent) showed an increase in murmur grade on repeat visit. Six dogs (17 per cent) showed an increase in aortic velocity of greater than 20 per cent. Eight dogs (23 per cent) had developed aortic valvular or subvalvular two-dimensional echocardiographic changes that had not been present at the initial visit. Seven dogs (20 per cent) had developed aortic regurgitation, and three dogs (8 per cent) mitral regurgitation.

Animals↗

PMS-601, a new platelet-activating factor receptor antagonist that inhibits human immunodeficiency virus replication and potentiates zidovudine activity in macrophages.

We assessed the anti-human immunodeficiency virus (anti-HIV) activity in vitro of new platelet-activating factor (PAF) receptor antagonists, as PAF and viral replication are thought to be involved in HIV neuropathogenesis. We found that PMS-601 inhibited proinflammatory cytokine synthesis and HIV replication in macrophages and potentiated the antiretroviral activity of zidovudine. These results suggest that PMS-601 is of potential value as an adjuvant treatment for HIV infection.

Anti-HIV Agents↗