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M Martin

Publications and source records attributed to M Martin.

At least 145 records · Page 8Linked to original sources
PubMed2001

Distinct cytokine regulation by cholera toxin and type II heat-labile toxins involves differential regulation of CD40 ligand on CD4(+) T cells.

Cholera toxin (CT) and the type II heat-labile enterotoxins (HLT) LT-IIa and LT-IIb act as potent systemic and mucosal adjuvants and induce distinct T-helper (Th)-cell cytokine profiles. In the present study, CT and the type II HLT were found to differentially affect cytokine production by anti-CD3-stimulated human peripheral blood mononuclear cells (PBMC), and the cellular mechanisms responsible were investigated. CT suppressed interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-alpha), and IL-12 production by PBMC cultures more than either LT-IIa or LT-IIb. CT but not LT-IIa or LT-IIb reduced the expression of CD4(+) T-cell surface activation markers (CD25 and CD69) and subsequent proliferative responses of anti-CD3-stimulated T cells. CT but not LT-IIa or LT-IIb significantly reduced the expression of CD40 ligand (CD40L) on CD4(+) T cells. In a coculture system, CT-treated CD4(+) T cells induced significantly less TNF-alpha and IL-12 p70 production by both autologous monocytes and monocyte-derived dendritic cells than either LT-IIa- or LT-IIb-treated CD4(+) T cells. These findings demonstrate that CT, LT-IIa, and LT-IIb differentially affect CD40-CD40L interactions between antigen-presenting cells and T cells and help explain the distinct cytokine profiles observed with type I and type II HLT when used as mucosal adjuvants.

Antibodies, Monoclonal↗
PubMed2001

Kinectin is a key effector of RhoG microtubule-dependent cellular activity.

RhoG is a member of the Rho family of GTPases that activates Rac1 and Cdc42 through a microtubule-dependent pathway. To gain understanding of RhoG downstream signaling, we performed a yeast two-hybrid screen from which we identified kinectin, a 156-kDa protein that binds in vitro to conventional kinesin and enhances microtubule-dependent kinesin ATPase activity. We show that RhoG(GTP) specifically interacts with the central domain of kinectin, which also contains a RhoA binding domain in its C terminus. Interaction was confirmed by coprecipitation of kinectin with active RhoG(G12V) in COS-7 cells. RhoG, kinectin, and kinesin colocalize in REF-52 and COS-7 cells, mainly in the endoplasmic reticulum but also in lysosomes. Kinectin distribution in REF-52 cells is modulated according to endogenous RhoG activity. In addition, by using injection of anti-kinectin antibodies that challenge RhoG-kinectin interaction or by blocking anti-kinesin antibodies, we show that RhoG morphogenic activity relies on kinectin interaction and kinesin activity. Finally, kinectin overexpression elicits Rac1- and Cdc42-dependent cytoskeletal effects and switches cells to a RhoA phenotype when RhoG activity is inhibited or microtubules are disrupted. The functional links among RhoG, kinectin, and kinesin are further supported by time-lapse videomicroscopy of COS-7 cells, which showed that the microtubule-dependent lysosomal transport is facilitated by RhoG activation or kinectin overexpression and is severely stemmed upon RhoG inhibition. These data establish that kinectin is a key mediator of microtubule-dependent RhoG activity and suggest that kinectin also mediates RhoG- and RhoA-dependent antagonistic pathways.

Animals↗
PubMed2001

Efficacy of clindamycin vaginal ovule (3-day treatment) vs. clindamycin vaginal cream (7-day treatment) in bacterial vaginosis.

OBJECTIVE: To compare the efficacy and safety of a 3-day regimen of clindamycin vaginal ovules with a 7-day regimen of clindamycin vaginal cream for the treatment of bacterial vaginosis (BV). METHODS: Women with a clinical diagnosis of BV were treated with a 3-day course of clindamycin ovules or a 7-day course of clindamycin cream administered intravaginally. Three hundred and eighty-four patients received study drug and were included in the evaluable patient population (ovule group, n = 204; cream group, n = 180). Assessments included pelvic examination and diagnostic testing. Primary efficacy endpoints were a resolution of two of three diagnostic criteria at the first follow-up visit and three of three diagnostic criteria at the second. RESULTS: Cure rates in the evaluable patient population were similar between treatment groups: 53.7% (109/204) for the ovule group and 47.8% (85/180) for the cream group (p = 0.2471, 95% CI -4.1-16.0%). The most commonly reported medical event, vulvovaginal pruritus, had similar incidence in both treatment groups. CONCLUSIONS: A 3-day course of clindamycin vaginal ovules is as effective and well-tolerated as a 7-day course of clindamycin vaginal cream in the treatment of BV.

Administration, Intravaginal↗
PubMed2001

The presence of thyrogastric antibodies in first degree relatives of type 1 diabetic patients is associated with age and proband antibody status.

A quarter of type 1 diabetic patients have thyrogastric autoantibodies (thyroid peroxidase and gastric parietal cell antibodies). Clinical, immune, and genetic risk factors help predict antibody status. First degree relatives of these patients may also frequently exhibit these antibodies. We assessed the prevalence of thyrogastric antibodies and dysfunction in first degree relatives in relation to age, gender, human leukocyte antigen-DQ type, beta-cell antibody (islet cell, glutamic acid decarboxylase-65, and tyrosine phosphatase antibodies), and proband thyrogastric antibody status. Sera from 272 type 1 diabetic patients (116 men and 156 women; mean age, 27 +/- 18 yr; duration, 10 +/- 9 y), 397 first degree relatives (192 men and 205 women; parents/siblings/offspring, 48/222/127; age, 22 +/- 10 yr), and 100 healthy controls were tested for islet cell antibodies and gastric parietal cell antibodies by indirect immunofluorescence and for tyrosine phosphatase, glutamic acid decarboxylase-65, and thyroid peroxidase antibodies by radiobinding assays. Glutamic acid decarboxylase-65 antibodies were present in 68% and 5%, islet cell antibodies were present in 36% and 2.5%, tyrosine phosphatase antibodies were present in 45% and 0.5%, thyroid peroxidase antibodies were present in 21% and 4.5%, and gastric parietal cell antibodies were present in 18% and 11% of diabetic patients and relatives, respectively. The presence of thyroid peroxidase antibodies in relatives was determined by age (beta = 0.22; P = 0.0001) and proband thyroid peroxidase antibodies status (beta = -2.6; P = 0.002; odds ratio = 11.1). Gastric parietal cell antibody positivity in relatives was associated with age (beta = 0.04; P = 0.026). Gastric parietal cell antibody-positive compared with gastric parietal cell antibody-negative relatives were more likely to have gastric parietal cell antibody-positive probands (P = 0.01; odds ratio = 3.0). beta-Cell antibody status and human leukocyte antigen-DQ type did not influence thyrogastric antibody status in relatives. (Sub)clinical dysthyroidism was found in 3%, iron deficiency anemia was present in 12% (26% gastric parietal cell antibody-positive and 9% gastric parietal cell antibody-negative subjects; P = 0.009), and pernicious anemia was found in 0.5% (5% gastric parietal cell antibody-positive and 0% gastric parietal cell antibody-negative subjects; P = 0.012) of relatives. They had less thyroid dysfunction (P < 0.0001) and pernicious anemia (P = 0.018) than diabetic probands. In conclusion, thyrogastric antibodies and dysfunction are more prevalent in type 1 diabetic patients than in first degree relatives. The presence of these antibodies in relatives is associated with age and proband antibody status, but not with beta-cell antibodies or human leukocyte antigen-DQ type.

Adult↗
PubMed2001

Activity of pemetrexed (ALIMTA, multitargeted antifolate, LY231514) in metastatic breast cancer patients previously treated with an anthracycline and a taxane: an interim analysis.

As many breast cancer patients receive adjuvant chemotherapy using anthracyclines or anthracenediones and taxanes, more therapeutic options are needed for subsequent lines of therapy. Pemetrexed (ALIMTA, multitargeted antifolate, LY231514) is a novel antifolate that inhibits several enzymes in the de novo pathways of pyrimidine and purine biosynthesis. This paper reports on a subset analysis of a phase II clinical trial of pemetrexed in heavily pretreated metastatic breast cancer (MBC) patients. Patients were required to have received prior first-line anthracycline therapy for metastatic disease. Prior adjuvant chemotherapy and prior taxanes were allowed. A substantial subset of the study population (31 of 72 patients, 43%) had also received a taxane in the metastatic setting. All patients were treated with pemetrexed, 600 mg/m2 by intravenous infusion, once every 21 days. In the study subset, 23 of 31 (74%) patients were anthracyclines failures (progression > 30 days following treatment), and eight (26%) patients were anthracyclines refractory (progression during or < or = 30 days of treatment). The median age was 55 years (range, 30-75 years) and the median World Health Organization performance status was 0. Metastases were present in the liver (61%), lung (29%), bone (6%), and soft tissue (19%). The overall response rate for this subset was 26%, with one complete response, seven partial responses, and 13 (42%) patients with stable disease. The median duration of response was 5.4 months and median survival was 12.8 months. Pemetrexed was well tolerated by patients in the study. This post hoc analysis suggests promising activity in MBC patients previously treated with both anthracyclines and taxanes. An ongoing trial is prospectively evaluating activity in this same population.

Adult↗
PubMed2001

[Spontaneous thrombosis of left varicocele].

Spontaneous thrombosis of a varicocele is a rare event and difficult to diagnose, as the clinical symptoms during the acute phase can simulate torsion of the spermatic cord or strangulated inguinal hernia leading to a useless surgical exploration. The authors report a case of spontaneous thrombosis of a varicocele which was diagnosed clinically, allowing conservative medical treatment.

Adult↗
PubMed2001

Uterine artery embolization to treat uterine fibroids.

Except for choice of embolization agent, the technique of uterine artery embolization for the treatment of fibroids is similar to that performed as emergent therapy for hemorrhage. The unique and more difficult aspects of fibroid embolization relate to patient recruitment and periprocedural care. There are few procedures in interventional radiology where timely and thoughtful pre- and postprocedure care are as important to building a practice. This is because of the intense and often prolonged clinical consequences of fibroid embolization, the attitude of many gynecologists toward interventional radiology and interventions for fibroids and especially because of the patient demographic. Patients seeking fibroid embolization tend to be highly motivated, educated women in their 20s to 40s with Internet access. The interventional radiologist unable to provide adequate answers or time to this group of patients in particular will find that they are an unforgiving lot!

Embolization, Therapeutic↗
PubMed2001

[Testicular trauma: report of 56 cases].

OBJECTIVES: To assess the diagnostic value of clinical examination and ultrasound in testicular trauma and to analyse the complications of the various treatments proposed (surgical and medical treatments), in order to more clearly define the place of medical treatment in this form of trauma in young adults. PATIENTS AND METHODS: 56 cases of testicular trauma in 50 patients were managed between January 1990 and January 2000. In the absence of clinical and ultrasonographic criteria of severity (haematocele, very large intratesticular haematoma, rupture of the tunica albuginea), medical treatment consisting of rest, anti-inflammatory drugs, and testicular support was instituted. Surgical exploration was performed when serious lesions of the testis were suspected. Three subgroup were defined: the medical treatment subgroup, the early surgical treatment subgroup, and the deferred surgical treatment subgroup (more than 3 days after trauma). The immediate morbidity and long-term sequelae were analysed in each of these three subgroups. RESULTS: The clinical features of pain and scrotal swelling make assessment of the lesions difficult. Testicular ultrasound can help the clinician, but it has a low sensitivity for the diagnosis of testicular rupture. No significant difference was observed between the three subgroups in terms of morbidity, orchidectomy, and long-term sequelae rates. CONCLUSION: In the absence of signs of severity, medical treatment with regular surveillance remains justified. However, in the case of doubtful clinical or ultrasound findings, surgical exploration must be performed as soon as possible.

Adolescent↗
PubMed2001

Adolescent premarital sexual activity, cohabitation, and attitudes toward marriage.

Societal trends indicate ambivalent attitudes about marriage. Specifically, there is greater acceptance of divorce and nontraditional living arrangements such as cohabitation, as well as acceptance and prevalence of premarital sex, than in the past. The authors examine adolescent attitudes toward marriage and their association with premarital sexual activity and cohabitation. Recommendations for helping adolescents understand the realities of marriage and family life are shared.

Adolescent↗
PubMed2000

Isotherm Model Analysis for the Adsorption of Cd (II), Cu (II), Ni (II), and Zn (II) on Anaerobically Digested Sludge.

Adsorption of Cd (II), Cu (II), Ni (II), and Zn (II) from aqueous solutions on anaerobically digested sludge has been investigated. Experimental data has been fit to Langmuir, Freundlich, and Redlich-Peterson isotherms to obtain the characteristic parameters of each model. Based on the maximum adsorption capacity obtained from the Langmuir and the Redlich-Peterson isotherm the affinity of the studied metals for the sludge has been established as Cu (II)>Cd (II)>Zn (II)>Ni (II). Adsorption tests from multimetal systems confirm the affinity order obtained in the individual metal tests. The adsorption capacity for Cu (II) measured in individual tests is not reduced by the presence of the other above referred metals. Desorption of Zn (II) and Cd (II) previously bound to the sludge in front of Cu (II) and HCl solutions is also reported. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Flt3 ligand lessens the growth of tumors obtained after colon cancer cell injection in rats but does not restore tumor-suppressed dendritic cell function.

A defective function of the antigen-presenting cells may represent one of the ways used by cancer cells to escape the immune response. We have previously shown that human and rat colon carcinomas were infiltrated by dendritic cells that did not express the B7 co-stimulatory molecules required for inducing an efficient T-cell response. Flt3 ligand is a cloned hematopoietic growth factor that markedly augments the number of functional dendritic and NK cells in lymphoid and non-lymphoid tissues and exerts anti-tumor activity in various experimental models. We show here that repeated Flt3 ligand administration delays the s.c. growth of rat colon cancer cells in syngeneic animals without inducing tumor regression. In tumor-bearing animals, Flt3 ligand has a limited stimulatory effect on the antigen-presenting capacity of intra-tumoral and splenic dendritic cells, without restoring the high functional level of dendritic cells from tumor-free animals. Moreover, Flt3 ligand-mediated activation of NK cell cytotoxicity decreases when the tumor mass increases. Our results indicate that Flt3 ligand treatment of tumor-bearing animals does not sufficiently overcome tumor-induced immunosuppression to restore the inhibited functions of dendritic and NK cells and allow complete tumor regression.

Animals↗
PubMed2000

Structure-activity relationships in platelet-activating factor (PAF). 10. From PAF antagonism to inhibition of HIV-1 replication.

Excessive levels of PAF and cells of macrophage lineage appear to play an important role in neuronal cell injury, inflammatory syndrome, and HIV replication in CNS resulting in AIDS dementia complex (ADC). The beneficial effects of PAF receptor antagonists are evident and give rise to expected therapeutic strategies for neurotrauma. Piperazine derivatives bearing a "cache-oreilles" (ear-muff) electronic distribution are able to inhibit in vitro PAF effects and, thus, could be used in pathologies where this mediator is involved. Therefore, their potential anti-HIV activity was investigated, and we find that (i) these PAF antagonists are effectively active in HIV-infected monocyte-derived macrophages (MDM) but there is no correlation between both anti-HIV and anti-PAF activities; (ii) the presence of a carbamate function (compounds 1a-d) is favorable to the antiviral activity; (iii) the lipophilicity of the substituent on the piperazinic cycle seems to be less important for the anti-PAF activity than for the antiviral one. Our leading compound, PMS 601 (compound 1a), presents a dual activity with IC(50) of 8 and 11 microM for anti-PAF and anti-HIV activity, respectively, without cytotoxic events at 1000 microM in MDM. Although its mode of action is not clearly defined, these data suggest that PMS 601, which displays no effect on acellular reverse transcriptase or protease tests, deserves further investigation in the treatment of HIV-1-associated dementia.

Anti-HIV Agents↗
PubMed2000

Na+-dependent high-affinity glutamate transport in macrophages.

Excessive accumulation of glutamate in the CNS leads to excitotoxic neuronal damage. However, glutamate clearance is essentially mediated by astrocytes through Na+-dependent high-affinity glutamate transporters (excitatory amino acid transporters (EAATs)). Nevertheless, EAAT function was recently shown to be developmentally restricted in astrocytes and undetectable in mature astrocytes. This suggests a need for other cell types for clearing glutamate in the brain. As blood monocytes infiltrate the CNS in traumatic or inflammatory conditions, we addressed the question of whether macrophages expressed EAATs and were involved in glutamate clearance. We found that macrophages derived from human blood monocytes express both the cystine/glutamate antiporter and EAATs. Kinetic parameters were similar to those determined for neonatal astrocytes and embryonic neurons. Freshly sorted tissue macrophages did not possess EAATs, whereas cultured human spleen macrophages and cultured neonatal murine microglia did. Moreover, blood monocytes did not transport glutamate, but their stimulation with TNF-alpha led to functional transport. This suggests that the acquisition of these transporters by macrophages could be under the control of inflammatory molecules. Also, monocyte-derived macrophages overcame glutamate toxicity in neuron cultures by clearing this molecule. This suggests that brain-infiltrated macrophages and resident microglia may acquire EAATs and, along with astrocytes, regulate extracellular glutamate concentration. Moreover, we showed that EAATs are involved in the regulation of glutathione synthesis by providing intracellular glutamate. These observations thus offer new insight into the role of macrophages in excitotoxicity and in their response to oxidative stress.

ATP-Binding Cassette Transporters↗
PubMed2000

TGF-beta1 and radiation fibrosis: a master switch and a specific therapeutic target?

Radiation fibrosis is a frequent sequel of therapeutic or accidental radiation overexposure in normal human tissues. One of the main fundamental problems yet unsolved in fibrotic tissues is the origin of the chronic activation of myofibroblasts within these tissues. It has been postulated that this chronic activation results from a continuous production of activating factors. In this context, fibrosis could be defined as a wound where continuous signals for tissue repair are emitted. Cytokines and growth factors probably play a central role in this process. Among them, transforming growth factor-beta1 (TGF-beta1) is considered as a master switch for the fibrotic program. This review discusses recent evidence on the critical role played by TGF-beta in the initiation, development, and persistence of radiation fibrosis. It summarizes the results concerning this factor after irradiation of various tissues and cells, with an emphasis on superficial fibrosis, including skin and subcutaneous tissues. Finally, recent data concerning the treatment of established fibrotic disorders of various etiology are presented, as well as the possible mechanisms involved in fibrosis regression, which show that the TGF-beta pathway may constitute a specific target for antifibrotic agents.

Animals↗