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Biomedical subjects

C Martin

Publications and source records attributed to C Martin.

At least 19 recordsLinked to original sources
PubMed2007

Free fetal DNA is not increased before 20 weeks in intrauterine growth restriction or pre-eclampsia.

BACKGROUND: The aim of this study was to quantify maternal plasma fetal DNA and total DNA in early pregnancy in intrauterine growth restriction (IUGR) or pre-eclampsia (PET). METHODS: A nested case control study was carried out in a University Teaching Hospital. Plasma samples were obtained from 1993 women before 20 weeks of gestation. Pregnancies complicated by IUGR or PET were identified and compared to controls. DNA was extracted and real-time quantitative PCR applied for the SRY and beta-actin genes. IUGR or PET groups were compared to controls using the chi(2) and Wilcoxon rank sum tests. RESULTS: SRY was detected in 86% of IUGR (31/36), 94% of PET (15/16) and 78% of controls (56/72). The median SRY was similar in women with IUGR (28 GE/mL) or PET (30.5 GE/mL) and controls (27.5 GE/mL). beta-actin was increased in the IUGR group (3975 GE/mL) compared to controls (1835 GE/mL) (p = 0.045). Cigarette consumption was greater in the IUGR group compared to controls (p = 0.004). CONCLUSIONS: Fetal DNA quantitation in maternal plasma before 20 weeks is not a useful predictor of IUGR or PET. beta-actin levels were elevated before 20 weeks in women with IUGR and may be a marker of maternal susceptibility to this condition.

Actins↗
PubMed2007

Immunological responses and protective immunity against tuberculosis conferred by vaccination of Balb/C mice with the attenuated Mycobacterium tuberculosis (phoP) SO2 strain.

The Mycobacterium tuberculosis phoP mutant strain SO2 has been shown previously to be more attenuated than Mycobacterium bovis bacillus Calmette-Guérin (BCG) and confers protective immunity against tuberculosis in mice and guinea pig models. In this study we have investigated the survival and immunological responses of Balb/c mice infected with the M. tuberculosis SO2 strain. All Balb/C mice survived intratracheal infection with M. tuberculosis SO2 strain under conditions where all the mice infected with the parental M. tuberculosis MT103 had died after 9 weeks. Infection of Balb/c mice with M. tuberculosis SO2 was associated with comparatively lower levels of interferon (IFN)-gamma, interleukin (IL)-4 and tumour necrosis factor (TNF)-alpha and higher levels of inducible nitric oxide synthase (iNOS) during the late stage of infection, when compared with M. tuberculosis MT103 infection. The delayed-type hypersensitivity (DTH) response against M. tuberculosis culture filtrates was similar in mice infected with either the M. tuberculosis phoP SO2 strain or M. tuberculosis MT103. The protective efficacy of M. tuberculosis SO2 was compared with M. bovis BCG when delivered subcutaneously to groups of Balb/C mice. Following intratracheal challenge with M. tuberculosis H37Rv, protection was generated by 60 days post-challenge in mice vaccinated with either vaccine. At day 120 post-challenge the levels of protection were still significantly greater when compared with the non-vaccinated control group. The levels of protection conferred by vaccination with M. tuberculosis SO2 or with M. bovis BCG were similar, as measured by granuloma coalescence and pneumonia in addition to growth reduction of M. tuberculosis H37Rv.

Animals↗
PubMed2006

Cytoprotective effect against UV-induced DNA damage and oxidative stress: role of new biological UV filter.

The majority of chemical solar filters are cytotoxic, particularly on sensitive ocular cells (corneal and conjunctival cells). Consequently, a non-cytotoxic UV filter would be interesting in dermatology, but more especially in ophthalmology. In fact, light damage to the eye can be avoided thanks to a very efficient ocular antioxidant system; indeed, the chromophores absorb light and dissipate its energy. After middle age, a decrease in the production of antioxidants and antioxidative enzymes appears with accumulation of endogenous molecules that are phototoxic. UV radiations can induce reactive oxygen species formation, leading to various ocular diseases. Because most UV filters are cytotoxic for the eye, we investigated the anti-UV properties of Calophyllum inophyllum oil in order to propose it as a potential vehicle, free of toxicity, with a natural UV filter action in ophthalmic formulation. Calophyllum inophyllum oil, even at low concentration (1/10,000, v/v), exhibited significant UV absorption properties (maximum at 300nm) and was associated with an important sun protection factor (18-22). Oil concentrations up to 1% were not cytotoxic on human conjunctival epithelial cells, and Calophyllum inophyllum oil appeared to act as a cytoprotective agent against oxidative stress and DNA damage (85% of the DNA damage induced by UV radiations were inhibited with 1% Calophyllum oil) and did not induce in vivo ocular irritation (Draize test on New Zealand rabbits). Calophyllum inophyllum oil thus exhibited antioxidant and cytoprotective properties, and therefore might serve, for the first time, as a natural UV filter in ophthalmic preparations.

Animals↗
PubMed2006

Modulated expression of cell surface molecules and in vivo outgrowth of modified melanoma cells.

Modulation of cell surface molecules involved in immune recognition and cellular interactions (class I major histocompatibility complex or MHC-I, B7.1 or CD80, integrin alpha4 or CD49d, tetraspanins CD9, CD81) was examined in modified B16 melanoma cells displaying either inhibited IGF-I expression or transfected OVA encoding gene. It was shown that inhibiting IGF-I expression or inserting OVA encoding gene did not lead to modification relevant to the presence of MHC-I or B7.1. However downregulation of tetraspanin CD9 was observed in modified IGF-I but not in OVA encoding gene inserted melanoma cells. Expression of tetraspanin CD81 and integrin alpha4/CD49d remained unchanged. Inoculated into syngeneic recipients, the modified melanoma cells exhibited significant delayed outgrowth with a reduction in the percentage of lethal tumors observed essentially in hosts injected with inhibited IGF-I expression cells.

Animals↗
PubMed2006

Salt and solvent effects on the kinetics and thermodynamics of the inclusion of the ruthenium complex [Ru(NH3)5(4,4'-bpy)]2+ in beta-cyclodextrin.

The influences of solvents (in water-cosolvent mixtures) and salts on the kinetics and thermodynamics of the inclusion of [Ru(NH3)5(4,4'-bpy)]2+ in beta-cyclodextrin (beta-CD) have been studied. Solvent effects on the kinetics can be described as a consequence of the competition of the cosolvent for the beta-CD cavity. The salt effects on the kinetics depend on the ion pairing of the anions with the [Ru(NH3)5(4,4'-bpy)]2+ complex. On the other hand, the solvent effects on the equilibrium constant depend on the stabilization of the 4,4'-bipyridine ligand in the water-cosolvent mixture relative to water. Finally, salt effects on the equilibrium constant are interpreted as a consequence of ion pairing between the anion of the salt and the inclusion complex.

Kinetics↗
PubMed2006

Characterisation of guinea pig precision-cut lung slices: comparison with human tissues.

Precision-cut lung slices (PCLS) allow comparison of the airway responses of different species under identical experimental conditions. The aim of this study was to establish and characterise PCLS from guinea pigs (GPs) and to compare them with human PCLS. GP PCLS were prepared according to previously published procedures with the exception that the agarose solution and the initial incubation medium contained isoproterenol to avoid post mortem airway contraction. The median effective concentrations (EC50, expressed as nM) for agonist-induced bronchoconstriction in GP and human PCLS, respectively, were: leukotriene D4 (1.8, 5.0); thromboxane (16, 1.3); serotonin (69, unresponsive); histamine (217, 2,170); and methacholine (231, 234). Allergen-induced bronchoconstriction of passively sensitised PCLS was attenuated by histamine or thromboxane-prostanoid receptor antagonists and was almost completely prevented by their combination with leukotriene receptor antagonists. Airways pre-contracted with methacholine were relaxed by the beta-agonist salbutamol or the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine. Simultaneous studies of airways and vessels are possible with, for example, EC50 values for endothelin-1 of 37 nM (pulmonary arteries), 10 nM (pulmonary veins) and 9.6 nM (airway). When compared with previous findings in rat and mouse, these data show that guinea pig lungs are a more appropriate model for human airway pharmacology than lungs from rats or mice.

Animals↗
PubMed2006

[Management of ventilator acquired pneumonia].

Ventilator-associated pneumonia occurs in the evolution of 8 to 70% of patients in the Intensive Care Unit. It is the main site of nosocomial infection for mechanically ventilated patients. Nosocomial pneumonia represents an important cause of morbidity and mortality, despite progresses in antibiotic prescription, use of intensive care and prevention. This review is based on the ATS guidelines, and reviews epidemiology, diagnosis and treatment of ventilator-acquired pneumonia, in non-immunocompromised adults.

Anti-Bacterial Agents↗
PubMed2006

[How about blood pressure in brain injury?].

One of the goals of the medical management of head injured patients is to get a cerebral perfusion pressure between 60 and 70 mmHg. To reach such a goal, catecholamines are used after fluid challenge. Systemic effects of catecholamines depend on their affinity for the receptors alpha and beta. The topical application of norepinephrine (alpha predominant) induced a vasoconstriction on large cerebral arteries only. Cerebral blood flow increased in the pericontusionnal area, suggesting a loss of autoregulation. The topical application of dopamine at low concentration relaxed large cerebral arteries. Dopamine increased cerebral blood flow in the pericontusional area but data suggest a possible raise in the volume of contusion. Four human comparative studies have been published. The first study, which was not randomized, showed an intracranial pressure increase associated with dopamine. Two randomized clinical trials, published by the same group, demonstrated a better predictability with norepinephrine. The fourth study did not find any difference regarding cerebral haemodynamics. In conclusion, the quality of data on the effects of catecholamines on cerebral haemodynamics of head injured patients do not make it possible to conclude about their use.

Animals↗
PubMed2006

Delay in referral of oropharyngeal squamous cell carcinoma to secondary care correlates with a more advanced stage at presentation, and is associated with poorer survival.

Squamous carcinoma of the oropharynx presents with symptoms common to many benign diseases, and this can cause delay in referral to secondary care. We investigate delay in referral, defining this as the time from symptom-onset to date of general practitioners referral letter to secondary care, and the effect of that delay, using a retrospective case notes based study of patients presenting at our institution with oropharyngeal squamous carcinoma between 1995 and 2005. Using correlation analysis and ordinal regression, we examined the relationship between increased referral delay from primary care, clinical stage at presentation, and survival. Increasing time from symptom onset to referral to secondary care was positively correlated with more advanced disease stage at presentation (r(s) = +0.346, P = 0.004). This was confirmed with ordinal regression modelling (delay estimate = 0.045, P = 0.042). Patients with delay of less than 6 weeks had significantly improved survival compared to those with a delay of greater than 6 weeks (P = 0.032). For every 1 week of delay in referral, we estimate that the stage of presentation will progress by 0.045 of 'a stage'.

Adult↗
PubMed2006

Topoisomerase II-alpha expression increases with increasing Gleason score and with hormone insensitivity in prostate carcinoma.

AIM: To investigate and compare topoisomerase II-alpha expression in benign prostatic hyperplasia (BPH), prostate cancer of varying Gleason scores and hormone-insensitive prostate cancer. METHODS: The immunohistochemical expression of topoisomerase II-alpha antibody in the above-mentioned diagnostic categories was investigated and compared. RESULTS: Increased expression of topoisomerase II-alpha was seen in the prostate cancers of Gleason scores 7 and 8-10 (p = 0.000) compared with prostate cancers of Gleason score 6 and BPH (p = 0.245). Statistically significant differences were found in the topoisomerase II-alpha gene expression between prostate cancers categorised by Gleason Score. Also, increased expression of topoisomerase II-alpha was seen in the known hormone-resistant prostate carcinomas compared with prostate cancers with no hormone treatment in the subgroup with Gleason scores 8-10, which approached statistical significance (p = 0.081). No statistically significant difference was observed in topoisomerase II-alpha expression between the groups with BPH and prostate carcinoma of Gleason score 6 (p = 0.245). CONCLUSION: Topoisomerase II-alpha expression was found to increase with the known prognostic marker Gleason score and with hormone insensitivity. Objective evidence is provided for clinical trials with drugs targeting topoisomerase II-alpha to be targeted to patients with prostate cancers of Gleason Score >6 and, in particular, prostate cancers of Gleason Scores 8-10.

Adenocarcinoma↗
PubMed2006

The use of mutant mycobacteria as new vaccines to prevent tuberculosis.

Given the variable protective efficacy generated by Mycobacterium bovis BCG (Bacillus Calmette-Guérin), there is a concerted effort worldwide to develop better vaccines that could be used to reduce the burden of tuberculosis. Rational attenuated mutants of Mycobacterium tuberculosis are vaccine candidates that offer some potential in this area. In this paper, we will discuss the molecular methods used to generate mutant mycobacteria, as well as the results obtained with some of these strains, in terms of attenuation, immunogenicity and level of protection, when compared with the conventional BCG vaccine in diverse animal models. Tuberculosis vaccine candidates based on safe and live mycobacterial mutants could be promising candidates.

Animals↗
PubMed2006

Age-dependent effects on redox status, oxidative stress, mitochondrial activity and toxicity induced by fluoroquinolones on primary cultures of rabbit tendon cells.

The age-related difference in fluoroquinolone-induced tendon toxicity was investigated. In vitro tendon cells from juvenile and young adult rabbits, respectively, were incubated with quinolone (nalidixic acid, NA) or fluoroquinolone (ofloxacin, OFX or pefloxacin, PEF) at 0.01 microM to 1 mM for 72 h. Redox status, glutathione (GSH), reactive oxygen species (ROS), and mitochondrial activity were assessed using intracellular fluorescent probes. Fluorescence signal was detected on living adherent tenocytes in microplates using cold-light cytofluorometry. Tendon toxicity differed significantly between the two cell groups and the difference was greatest with highest dose (1 mM). For 72 h, significant (p < 0.001) differences between immature and young adult primary tenocytes were observed for redox status decrease, GSH decrease, and ROS production increase. Mitochondrial activity remained unaltered in immature tenocytes. We confirm two groups of intrinsic tendon toxicity (OFX/NA vs. PEF) associated to oxidative stress (GSH decrease). Our in vitro experimental model confirms the clinical observations of age dependent tenotoxicity. First group (NA, OFX) showed greater intrinsic tenotoxicity for young adult than immature tenocytes, second group (PEF) was highly toxic for immature and young adult cells. The three quinolones do not altered mitochondrial activity in immature tenocytes whereas alteration was observed in young adult tenocytes.

Achilles Tendon↗
PubMed2006

Separation of technical 4-nonylphenols and their biodegradation products by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry.

Comprehensive two-dimensional gas chromatography (GC x GC) coupled to time-of-flight mass spectrometry (TOF-MS) was applied to improve the separation of 4-nonylphenol isomers and their biodegradation products. The structurally similar nonylphenol isomers were separated by combining a 30 m long semi-polar column and a short polar capillary. Both were coupled via a custom-made liquid nitrogen cryogenic modulator. The advanced GC resolution of coeluting isomers, additionally supported by fast scanning TOF-MS, provided clearer, non-interfered mass spectra of individual isomers. Thus, identification of components is facilitated as shown for isomeric 4-nonylphenols and metabolites of their biodegradation by Clavariopsis aquatica, an aquatic fungus. GC x GC-TOF-MS analysis enabled the separation of about 40 alkylphenol isomers included in technical 4-nonylphenol. During biodegradation the variety of emerging compounds increased with longer reaction time. The comprehensive analysis indicated a broad spectrum of hydroxylated, carboxylated nonylphenolisomers and additionally, chlorinated aromatic compounds produced and released from the fungal culture.

Biodegradation, Environmental↗
PubMed2006

[Referred pain from amputation stump trigger points into the phantom limb].

OBJECTIVES: The aim of the study was to examine whether/how myofascial stump trigger points (TPs) after lower leg amputations are able to produce stump pain (SP), phantom pain (PP), and sensations (PS) in the phantom limb. METHODS: Palpation of the 5 most striking stump TPs of 30 leg amputees (12 transfemoral, 18 transtibial) was documented in a standardized manner. Patients were asked to localize SP, PP, and PS. RESULTS: Of 150 TPs, 14 produced involuntary stump movements and 10 stump fasciculations. Dorsal PP after ventral TP palpation occurred as well as PP in the toes from TPs near the hip. Of 30 patients, 20 reported PS and 8 PP; 60 of 150 TPs produced PS and 17 PP. Phantom phenomena were localized in 62.8% in the toes (1st toe 19.8%, toes 2-5 about 10% each), 17.9% midfoot, and the rest were more proximal. TPs were localized more in the lateral/dorsal stump than medial/ventral. About 70% of the TPs were found between 3 and 7 cm from the stump end, those with toe projections more distal than those with tibial projections. CONCLUSIONS: Myofascial TPs in amputation stumps are common and able to produce sensations and pain in the phantom limb. Most reported experiences were localized in the toes, as phantom pain usually is. There seems to be a "stump representation" and it seems possible that "referred TP pain" and "phantom pain" may develop from similar origin.

Humans↗
PubMed2006

[Cytotoxicity evaluation of different eyes drops with cyclosporine oral solution (Sandimmun)].

INTRODUCTION: Cyclosporine is a molecule used in ophthalmology for the prevention of corneal graft rejection. The systemic use of this product can lead to serious adverse side effects that can be avoided using the topical formulation of cyclosporine. However, cyclosporine application can induce ocular irritation. MATERIAL AND METHODS: The aim of this study is to evaluate the cytotoxicity of four formulations of 2% cyclosporine eye drops: Sandimmum intravenous solution diluted with NaCl 0.9%, Sandimmun oral solution diluted in castor oil or corn oil after ethanol evaporation, and Sandimmun oral solution diluted in castor oil without previous ethanol evaporation. Two tests--the Draize test and the evaluation of cytotoxicity of adherent alive cells with cold light cytofluorimetry on microplates--were used in this study. RESULTS: These tests demonstrated that the aqueous solution shows more toxicity than the other formulations, and the type of oil and ethanol concentration influence cell viability. CONCLUSION: These results helped the Pharmacy unit choose the vehicles for a safe cyclosporine eye drop formulation and thus decrease the side effects of cyclosporine eye drop instillation with a decrease in ethanol concentration compared to published formulations.

Administration, Oral↗
PubMed2006

First report of Litomosa spp. (Nematoda: Filarioidea) from Malagasy bats; review of the genus and relationships between species.

The presence of the filarial genus Litomosa in Malagasy bats is demonstrated by the finding of L. goodmani n. sp. from Miniopterus gleni and Litomosa sp. (male unknown) from M. manavi, both in the Special Reserve of Ankarana. These materials are compared to the 22 Litomosa species, including two Indian species originally placed in the genus Litomosoides, L. fotedari (Gupta and Trivedi, 1989) n. comb. and L. tewarii (Gupta and Trivedi, 1989) n. comb., and the new taxon L. seurati n. sp. (= L. beaucournui Bain, 1966 pro parte), type-host Rhinolophus ferrum-equinum, Algeria, distinguished by the narrow area rugosa and the female caudal extremity with two conspicuous points, instead of several small ones. The Malagasy material belongs to a group of species close to the type, L. filaria, which have a male area rugosa composed of cuticular bosses and microfilariae folded within the sheath, and which are parasitic in Vespertilionidae, Hipposideridae and Rhinolophidae from Africa and Europe. The two Malagasy species resemble L. seurati n. sp., L. beshkovi Jancev, 1971, L. chiropterum Ortlepp, 1932, L. adami Petit, 1980 and L. ottavianii Lagrange et Bettini, 1948, with the enlarged third segment of the buccal capsule. L. goodmani n. sp. is distinct with its small size and female caudal extremity with a single point, which is suppressed in old mature worms; the females of Litomosa sp. have two conical points. Relationships among Litomosa species appear to be dependent upon both the chiropteran host groups and the geographical region.

Animals↗