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Biomedical subjects

M Martin

Publications and source records attributed to M Martin.

At least 37 records · Page 2Linked to original sources
PubMed2005

Evolution of the meiotic prophase and of the chromosome pairing process during human fetal ovarian development.

BACKGROUND: Studies on human oocytes in prophase I are limited due to the difficulty in obtaining the sample. However, a complete study of meiotic prophase evolution and the homologue pairing process is necessary to try to understand the implication of oogenesis in the origin of human aneuploidy. METHODS: A complete analysis of meiotic prophase progression comprising the long developmental time period during which meiotic prophase takes place, based on the analysis of a total of 8603 oocytes in prophase I from 15 different cases is presented. The pairing process of chromosomes 13 and 18 is also described. RESULTS: The findings significantly relate for the first time the evolution of meiotic prophase to fetal development. Although for both chromosomes 13 and 18 a high pairing efficiency is found, pairing failure at the pachytene stage has been observed in 0.1% of oocytes. However, errors at the diplotene stage are substantially increased, suggesting that complete, premature disjunction of the homologues commonly occurs. Moreover, pre-meiotic errors are also described. CONCLUSIONS: Our findings show that homologous chromosomes pair very efficiently, but the high frequency of complete, premature homologue separation found at diplotene suggests that mechanisms other than the pairing process could be more likely to lead to the high aneuploidy rate observed in human oocytes.

Aneuploidy↗
PubMed2005

Picometer-scale electronic control of molecular dynamics inside a single molecule.

Tunneling electrons from a low-temperature (5 kelvin) scanning tunneling microscope were used to control, through resonant electronic excitation, the molecular dynamics of an individual biphenyl molecule adsorbed on a silicon(100) surface. Different reversible molecular movements were selectively activated by tuning the electron energy and by selecting precise locations for the excitation inside the molecule. Both the spatial selectivity and energy dependence of the electronic control are supported by spectroscopic measurements with the scanning tunneling microscope. These experiments demonstrate the feasibility of controlling the molecular dynamics of a single molecule through the localization of the electronic excitation inside the molecule.

Journal Article↗
PubMed2005

Mutations in the quinolone-resistance determining region (QRDR) of Salmonella strains isolated from pigs in Spain.

Quinolone-resistance determining region (QRDR) of Gyrase A gene was sequenced in 54 Salmonella strains of pig origin that have different quinolone-resistance patterns. Those strains accounted for 12 different serotypes. Mutations at Ser83 or Asp87 were predominant in the studied isolates. However, for serotypes Anatum and Virchow, resistance to quinolones seemed to be linked to specific mutations, namely, Ser83-->Tyr and Ser83-->Phe, respectively. Other mutations found in different positions did not seem to have clinical significance except for changes at Asp82.

Animals↗
PubMed2005

Survival among hospital in-patients with troponin T elevation below levels defining myocardial infarction.

BACKGROUND: Cardiac troponin T (cTnT) has an accepted place in the management of patients presenting with suspected acute coronary syndrome (ACS). Uncertainty remains about the significance and interpretation of elevated cTnT below the cut-off levels defining myocardial infarction (0.1 microg/l). AIM: To compare the mortality risks for elevation of cTnT in the ranges 0.01-0.029 microg/l, 0.03-0.099 microg/l and <0.01 microg/l. DESIGN: Retrospective record study in three hospitals. METHODS: All cTnT measurements with values in the range >0.01-0.099 microg/l analysed during January 2002 were extracted from clinical biochemistry laboratory databases. Following agreed exclusion criteria, 179 patients with cTnT in the range 0.01-0.099 microg/l and 60 patients <0.01 microg/l were selected at random from across the three sites. Six-month follow-up was completed by review of case notes and contact with the patients' GP. RESULTS: There was a graded increase in mortality with increasing cTnT, although only achieving statistical significance for patients in the 0.03-0.099 microg/l range. The graded increase in relative risk with cTnT was weaker after adjustment for potential confounding factors DISCUSSION: We found a trend for worse survival with increasing cTnT within the range 0.01-0.099 microg/l in unselected patient populations presenting with possible acute coronary syndrome. This suggests that the combined effects of assay imprecision and co-morbidity should be taken into account when interpreting borderline elevation of cTnT. The use of a cut-off based on current standards of assay precision should be used to define the sensitivity of cTnT as biochemical evidence of ischaemic cardiac damage and as an indicator of mortality risk. This level is likely to be between 0.03 and 0.1 microg/l.

Aged↗
PubMed2005

Biocompatibility parameters of different dialysis membranes assessed during systemic inflammation.

BACKGROUND: We explored whether biocompatible dialyzer membranes modulate the inflammatory response during blood contact in patients with systemic inflammation. METHODS: 15 patients with end-stage renal disease and systemic inflammation (mean serum C-reactive protein 86 +/- 4 mg/l) were randomly treated with Cuprophan (CU), polyamide (PA) and vitamin-E coated (VEC) membrane-based dialyzers. RESULTS: Changes in blood pressure, capillary blood oxygen saturation and differential blood counts during the hemodialysis session were not significantly different between the three dialyzers. Baseline blood levels of activated circulating complement (C3a) were more than 100 times above normal, and unlike expected they decreased during hemodialysis treatments (CU: from 7,389 +/- 783 to 5,423 +/- 761 ng/ml; PA: from 7,379 +/- 980 to 5,690 +/- 714 ng/ml; VEC: from 7.377 +/- 714 to 5,360 +/- 1,005 ng/ml; all n.s.). No significant differences between treatments were found with respect to changes in blood concentrations of TNF-alpha, interleukin-6 and interleukin-1 receptor antagonist as well as ICAM-1 (CU: from 451 +/- 41 to 477 +/- 41 ng/ml; PA: from 437 +/- 42 to 449 +/- 40 ng/ml; VEC: from 461 +/- 43 to 460 +/- 47 ng/ml). Furthermore, generation of reactive oxygen species by mononuclear blood cells was comparable during hemodialysis with the CU, PA and VEC dialyzer. CONCLUSION: The choice of dialyzer membrane material does not affect most aspects of biocompatibility when patients have significant systemic inflammation. This confounding variable should be taken into account in studies exploring the effects of biocompatible dialyzer membranes.

Female↗
PubMed2005

[Not Available].

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Journal Article↗
PubMed2005

A decrease in the association between the physical activity patterns of Australian parents and their children; 1985-1997.

The present study investigated the interactions between parents' and children's physical activity levels by examining whether or not parents who exercise have children who participate in sport. Of primary interest was an investigation of trends in these interactions over time. Information was collected from 10-13 y old children in 1985 (n = 2463) and then again in 1997-99 (n = 1469), about their sports participation and their perceptions of parents' exercise habits. Boys' participation in at least one sport declined from 87% in 1985 to 76% in 1997/1999 while, among girls, participation fell from 80% to 71%. According to their children's perceptions, mothers exercising regularly fell from 36% to 31% between surveys, while fathers exercising regularly fell from 39% to 32%. Interactions between parents' and children's exercise and sports behaviours were examined employing chi-square analysis techniques. Results showed gender-specific relationships for the 1985 sample, such that active fathers were associated with increased participation in sports by boys, and inactive mothers were associated with less participation in sports by girls. These interactions seemed to diminish over time. It is possible that changes in social structures during this time may be affecting familial behaviour relationships, such as the role modelling of active behaviours.

Adolescent↗
PubMed2005

[Memory and planning].

The years before and after retirement are characterized by substantial changes in the lifes' of aging individuals. However, the same changes may be appraised as stressful, neutral, or positive, depending on the available skills, experiences, and future expectations. In other words, the subjective experience of cognitive aging strongly determines health-related behaviors and, thus, the effectiveness of treatments. An area of increasing concern in this age group is the development of one's cognitive abilities. The demand for adequate trainings to preventively maintain cognitive skills plays an important role. Persons may also start worrying if observed changes in their memory performance are still in the range of normal functioning or if they may represent early indications of dementia. This paper (a) briefly describes normal cognitive development between 50 and 75 years, (b) provides examples for the plasticity of cognitive abilities, (c) highlights the importance of subjective memory complaints for the detection of mental health and memory problems, and (d) suggests a procedure to help detecting memory problems early on.

Aged↗
PubMed2005

[Tweed-Merrifield technique and vertical dimension in hyperdivergent Class II].

The cases presented in this paper share a common skeletal characteristic, hyperdivergence, a common therapeutic strategy, similar diagnostic elements, and a common choice of non-symmetrical extractions. Interceptive treatment is especially useful for this type of malocclusion to prevent deep over-bites, atypical habits, and severe malocclusion. In the Tweed-Merrifeld technique, orthodontists use careful dental, occlusal, cephalometric, and esthetic evaluations to establish an appropriate treatment plan and therapeutic strategy whose goal will be: to eliminate unhealthy compensations, re-position, if necessary, alveolar structures on basal bone, reduce anterior-posterior and vertical discrepancies, favor anterior mandibular rotation, improve facial esthetics, restore functional occlusion, and assure stability of results. Because of its consistent capability of achieving predictable resolution of the most varied and complex orthodontic disorders, the author has chosen this technique for routine use in his daily orthodontic practice.

Cephalometry↗
PubMed2005

[Toxic optic neuropathy due to cisplatin therapy: a case report].

BACKGROUND: Optic neuropathies presenting as bilateral disc oedema lead to a vast field of differential diagnosis; a toxic aetiology should be taken into consideration. HISTORY AND SIGNS: A 55-year-old patient with a non-metastatic pleuramesothelioma received cisplatin as palliative chemotherapy. Due to a unilateral high myopia on the left eye the patient has a severe anisometropic amblyopia. The patient complained about visual loss and changed colour vision. Visual acuity was 0.1 on the right eye and counting fingers on the left eye. The anterior parts of the eyes were unremarkable, the optic nerve head showed bilateral disc oedema. The MRI was free of tumour or signs of elevated intracranial pressure. Colour vision test Panel D-15 revealed a pathologic colour perception affecting the tetartan-axis. Perimetry showed a cecocentral and superior bundle scotoma. THERAPY AND OUTCOME: The patient has been treated with methylprednisolone (Solu-Medrol) 500 mg i. v. 1 gr daily for three days, continued by 100 mg oral steroids successively reduced over a period of three weeks. After three weeks visual acuity increased to 0.3. CONCLUSIONS: Toxic neuropathies including disc oedema, retinal oedema and optic neuritis are rare, but have been described as occasional side effects of treatment with cisplatin.

Antineoplastic Agents↗
PubMed2005

Major plasma proteins in pig serum during postnatal development.

The time-course of changes in the levels of albumin, alpha-fetoprotein (AFP), alpha(1)-protease inhibitor (alpha(1)-antitrypsin), alpha(1)-acid glycoprotein, fetuin, haptoglobin, transferrin, IgG and the major acute-phase protein (Pig-MAP) in the blood sera of pigs during the first days and weeks of life was investigated by quantitative radial immunodiffusion. The serum of newborn pigs before suckling was characterised by a very low concentration of total proteins (approximately 25 mg mL(-1)), low levels of albumin and transferrin and the lack of immunoglobulins. In contrast, alpha(1)-acid glycoprotein and fetuin are present at high levels (approximately 12 and 5 mg mL(-1) respectively). The results of the present study show that the piglets undergo a very rapid metabolic maturation with regard to serum proteins, evolving from a characteristic 'fetal' pattern to an 'adult' one. We have paid special attention to the evolution of haptoglobin and Pig-MAP, which are two important acute-phase proteins in pigs. The evolution of serum levels of these proteins suggests that piglets must overcome a moderate acute-phase situation during the first week of life.

Acute-Phase Proteins↗
PubMed2005

Torsemide versus furosemide after continuous renal replacement therapy due to acute renal failure in cardiac surgery patients.

Diuretic therapy in ARF (acute renal failure) is mainly done with loop diuretics, first of all furosemide. Torsemide has a longer duration of action and does not accumulate in renal failure. In chronic and acute renal failure, both diuretics have been effectively applied, with a more pronounced diuretic effect for torsemide. In this study, the effects of torsemide versus furosemide on renal function in cardiac surgery patients recovering from ARF after continuous renal replacement therapy (CRRT) were studied. Twenty-nine critically ill patients admitted to an intensive care unit at a university teaching hospital after cardiac surgery recovering from ARF after CRRT were included in this prospective, controlled, single-center, open-labeled, randomized clinical trial. Inclusion criteria were urine output >0.5 mL/kg/h over 6 h under CRRT. Torsemide and furosemide dosages were adjusted with the target urine output being 0.8-1.5 mL/kg/h. Hemodynamic data, urine output, volume balance, serum creatinine clearance, electrolytes, blood urea nitrogen, serum creatinine, renin, and aldosterone concentrations were measured. Fourteen patients were included in the furosemide group and 15 patients in the torsemide group. Dosages of 29 (0-160) mg torsemide and a dosage of 60 (0-240) mg furosemide were given every 6 h in each group, respectively. The dosage given at the end of the study decreased significantly in furosemide and torsemide treated patients. Urine output, 24 h balance, and serum creatinine clearance did not differ significantly between groups. Urine output decreased in both groups, mostly dose-dependent in the torsemide group. The intragroup comparison of the first time-interval after inclusion with the last time-interval showed a significant increase in serum creatinine and blood urea nitrogen in the furosemide group. Renin and aldosterone concentrations did not show significant differences. In conclusion, torsemide and furosemide were effective in increasing urine output. Torsemide might show a better dose-dependent diuretic effect in ARF patients after CRRT treatment. Serum creatinine and blood urea nitrogen elimination were less pronounced in the furosemide group.

Acute Kidney Injury↗
PubMed2005

Atypical anti-psychotics in the real world--a naturalistic comparative outcome study.

BACKGROUND: There are few real life independent comparative studies of atypical antipsychotics. We prospectively examined five commonly used atypical antipychotics in the UK, without support from the pharmaceutical industry. METHOD: Prospective naturalistic systematic clinical evaluation. Patients being newly prescribed atypical anti-psychotics over a one year period were assessed by psychiatrists at initiation and after six months treatment using five outcome measures: clinical global impression; positive and negative psychotic symptoms; drug related side effects; and quality of life. RESULTS: 373 patients participated in total. Olanzapine and risperidone produced statistically significant reductions in all ratings at six months. Amisulpride, clozapine, and quetiapine were also studied. There was limited variance between the different drugs, although some sample sizes were small. CONCLUSION: Atypical anti-psychotics were found to be clinically effective, and produced similar outcomes. Routine monitoring of outcomes in psychiatry is feasible.

Adolescent↗
PubMed2005

Tuberculosis education in an endemic setting: application of participatory methods to video development in The Gambia.

OBJECTIVE: To produce an educational video for tuberculosis (TB) awareness in The Gambia using participatory methods and integrated formative evaluation. METHODS: A steering group was formed of key people working in TB research, health education, the health service and the media. They developed a script and commissioned local production of the video in three local languages and English. A formative participatory evaluation of the project was conducted using document review, attendance at rehearsals and semi-structured interviews. A pilot version of the video was evaluated through focus groups in Banjul and remote villages. Data were analysed using a general inductive approach. RESULTS: Five major themes emerged from evaluation of the project participatory process: collaboration, knowledge sharing, networking, ownership and a common desire to sustain the project goals for video dissemination. The video was well received and described as informative, entertaining and professional. Audiences were able to identify the key messages, prevailing attitudes about TB were challenged, and many participants expressed a desire to act on their new knowledge. CONCLUSION: A participatory approach to the development of a video in The Gambia proved to be empowering to local participants and led to the production of a resource well received by Gambian people.

Community Participation↗
PubMed2005

Gait abnormalities in older people--comparison of inter-professional assessment.

Gait abnormalities are common in older people but relatively under-diagnosed. We investigated the prevalence of gait abnormalities among patients presenting to a geriatric medicine day hospital, classified them according to whether they were lower, middle or higher level gait disorders and compared inter-professional (physician and physiotherapist) assessments for this classification. Prospective independent assessment by a physician and a senior physiotherapist of 50 consecutive patients presenting to a day hospital. Presence of a gait abnormality was determined and then classified. Levels of agreement were determined between the two professions. There was 98% agreement that a gait abnormality existed in 43 people. In classifying the gait abnormality there was complete agreement in over two-thirds of cases (67.4%). There was further agreement of higher level gait disorders (but disagreement in the sub-classification) in 11.6% of cases. Given the high prevalence of gait abnormality presenting to the day hospital, screening for gait and balance disorders should be of paramount importance. While levels of agreement between the two professions were high, disagreement existed in approximately one-third of cases. Agreement among professionals essential for appropriate tailoring of treatment and intervention.

Aged↗
PubMed2004

The effect of repeated tuberculin skin testing of cattle on immune responses and disease following experimental infection with Mycobacterium bovis.

The comparative intradermal skin test, in which a delayed type hypersensitivity (DTH) response to purified protein derivative of tuberculin (PPD) from Mycobacterium bovis and M. avium is assessed and compared, may be used repeatedly on non-infected animals on farms where bovine tuberculosis (TB) has occurred. A skin test is known to affect subsequent skin tests in infected animals. The reported study was to determine whether repeated skin testing prior to infection with M. bovis might affect the development of the comparative skin test and IFNgamma response subsequent to exposure to virulent M. bovis. The comparative intradermal skin test was applied to one group of six calves five times at 8-week intervals. These and six control calves were subsequently inoculated intratracheally with a dose of M. bovis that produced mild disease. The development of the DTH reaction, IFNgamma, IL-10 and proliferative responses were compared in the two groups of animals. No differences in IFNgamma, IL-10 and proliferative responses were seen between the two groups of calves prior to challenge. After infection with M. bovis no differences in the development of the DTH and IFNgamma responses to PPD were noted as a consequence of the repeated skin testing prior to challenge. No differences between the groups were evident when ESAT-6 was used as antigen and IFNgamma was assayed, although two animals that responded to PPD did not respond with ESAT-6. However, there did appear to be subtle effects of repeated skin testing on the immune response post-challenge that did not affect the diagnostic tests. After challenge control animals showed greater proliferative responses than animals given repeated skin tests prior to challenge, indicating that the procedure did have consequences for immune responses following infection. In both groups a marked reduction in the intensity of the skin test and in the number of animals that would be recognized as reactors was evident when animals were tested 15 weeks post-infection compared to their responses 8 weeks earlier that could have consequences for diagnosis of TB. An antibody response was not evident as a result of repeat skin testing prior to infection but was seen in both groups of calves following skin testing performed 7 weeks after infection.

Animals↗