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Biomedical subjects

A Berger

Publications and source records attributed to A Berger.

At least 19 recordsLinked to original sources
PubMed2006

Exchange bias training effect in coupled all ferromagnetic bilayer structures.

Exchange coupled bilayers of soft and hard ferromagnetic thin films show remarkable analogies to conventional antiferromagnetic/ferromagnetic exchange bias heterostructures. Not only do all these ferromagnetic bilayers exhibit a tunable exchange bias effect, they also show a distinct training behavior upon cycling the soft layer through consecutive hysteresis loops. In contrast with conventional exchange bias systems, such all ferromagnetic bilayer structures allow the observation of training induced changes in the bias-setting hardmagnetic layer by means of simple magnetometry. Our experiments show unambiguously that the exchange bias training effect is driven by deviations from equilibrium in the pinning layer. A comparison of our experimental data with predictions from a theory based upon triggered relaxation phenomena shows excellent agreement.

Journal Article↗
PubMed2006

[Cardiology].

Heart failure and atrial fibrillation are the main problems in general cardiology. Our therapeutic reflections summarize new ideas in the treatment of theses pathologies but we will not forget importance of PCI. All these therapies have proven now the clinical benefit but also reduction in more morbidity and mortality. Cardiac resynchronisation therapy has shown promising results. The art of medicine to develop will be to better identify the patients benefiting from this therapy. Interventional cardiology is focusing on the acute coronary syndrome. Not only rapid intervention but also the stent technology allow significant modification of endothelial tissue reaction and therefore improve the general benefit for the patient.

Atrial Fibrillation↗
PubMed2006

Use of antiepileptics and tricyclic antidepressants in cancer patients with neuropathic pain.

Using a large US health insurance claims database, we identified all persons aged > or =18 years with > or =2 medical encounters with diagnoses of cancer and > or =2 medical encounters with diagnoses of painful neuropathies in calendar year (CY) 2000; persons with seizure disorders or depression were excluded. We then examined the use of antiepileptics (AEDs), tricyclic antidepressants (TCAs) and other pain-related pharmacotherapy among these selected persons, as proxied by pharmacy dispenses. A total of 956 persons were identified who met all entry criteria; 17% received AEDs in CY2000 and 14% received TCAs. Gabapentin was the most widely used AED (92% of all AED patients); amitriptyline was the most widely used TCA (79% of all TCA patients). Patients who received AEDs and/or TCAs were similar in age, gender and the presence of metastases to those who had not received these medications; they were more likely to have received other pain-related therapies, however, including short-acting opioids (73% vs. 53%; P < 0.01) and long-acting opioids (23% vs. 8%; P < 0.01). Use of AEDs and TCAs appears to be relatively low among cancer patients with painful neuropathies. Further research is needed to better understand reasons for this finding, as well as its potential implications for pain management in this patient population.

Aged↗
PubMed2005

Management of defects in the groin, thigh, and pelvic region with modified contralateral TRAM/VRAM flaps.

In patients with sarcomas, or regional recurrence of the disease, radical resection and radiation therapy is indicated to achieve cure or palliation. As a result of radical surgery, extensive radiation, or infection in the pelvic, groin or thigh region, the development of large pelvic / groin / thigh defects present a difficult surgical problem. Musculocutaneous deep epigastric island-flaps, as a modification of the extended deep inferior epigastric flap, described by Taylor et al. in 1983, are an attractive option for a successful reconstruction for this defect localisation. Two technical modifications of the contralateral extended deep inferior epigastric island-flap permitted an adequate tailoring to a defect in the posterior lateral pelvic or groin-thigh region, and avoided the drawbacks of other loco-regional or microsurgical flaps in previously irradiated fields. The skin island reached the posterior lateral pelvic region, groin or thigh. The muscular portion of this flap was suited to fill the soft tissue defects in these critical areas. These so modified flaps represent an instrument, which in selected cases may be an interesting alternative tool for closure of complex defects. No significant functional impairment secondary to the flap procedures was noted in our patients.

Bone Neoplasms↗
PubMed2005

QTL analysis of fruit components in the progeny of a Rennell Island Tall coconut (Cocos nucifera L.) individual.

We investigated the genetic factors controlling fruit components in coconut by performing QTL analyses for fruit component weights and ratios in a segregating progeny of a Rennell Island Tall genotype. The underlying linkage map of this population was already established in a previous study, as well as QTL analyses for fruit production, which were used to complement our results. The addition of 53 new markers (mainly SSRs) led to minor amendments in the map. A total of 52 putative QTLs were identified for the 11 traits under study. Thirty-four of them were grouped in six small clusters, which probably correspond to single pleiotropic genes. Some additional QTLs located apart from these clusters also had relatively large effects on the individual traits. The QTLs for fruit component weight, endosperm humidity and fruit production were found at different locations in the genome, suggesting that efficient marker-assisted selection for yield can be achieved by selecting QTLs for the individual components. The detected QTLs descend from a genotype belonging to the "Pacific" coconut group. Based on the known molecular and phenotypic differences between "Pacific" and "Indo-Atlantic" coconuts, we suggest that a large fraction of coconut genetic diversity is still to be investigated by studying populations derived from crosses between these groups.

Chromosome Mapping↗
PubMed2005

[Cardiology].

The therapeutic acquisition to be retained for 2004 are: 1. The elderly patients with heart failure also should receive beta blocker treatment. The correction of anaemia, aggravating factor in heart failure, improves symptoms and survival of the patient. 2. It remains to prove that the treatment of sleep apnea, which seems to be an additional factor for mortality in cardiovascular diseases, is able to reduce the risk. 3. The interventions in the endocanabinoïd system which regulates weight and metabolic processes might be a promising new therapeutic acquisition. 4. Prevention of coronary disease with lipid lowering drugs is still a major topic, and the trend goes the lower the better. The problems observed with Rofecoxybe and other drug interactions reminds us to be conscious when prescribing multiple drugs. 5. The implantable defibrillator seems to be a life insurance in the event of ventricular fibrillation. However, it is not so easy to identify the patient who might really benefit.

Cardiovascular Diseases↗
PubMed2005

[Indications and results of operative treatment in birth-related brachial plexus injuries].

INTRODUCTION: A review of the literature reveals that under conventional treatment alone or in combination with secondary muscle/tendon transfer about 4 to 43 % of cases show incomplete recovery with severe functional and/or aesthetic impairment. When these patients undergo early microsurgical brachial plexus revision, a regeneration without any significant functional and/or aesthetic impairment can be achieved in 80 to 90 % of the cases. Moreover, microsurgical reconstruction of the brachial plexus does increase the possibilities of secondary muscle/tendon transfers. MATERIALS AND METHODS: Our concept is based on our experience with more than 1700 patients presenting with brachial plexus lesions between 1981 and 2000 who were treated in our institution. Patient selection is done according a standardized algorithm which is presented. There were 418 obstetrical brachial plexus lesions. 189 could be treated conservatively. In 225 cases operative treatment was necessary. 104 cases underwent early revision of the brachial plexus and secondary tendon transfer was done in 121 patients. RESULTS: Personal results and an analysis of the literature reveal that in C5/C6 lesions good shoulder function can be achieved in 60 to 80 %, especially if the accessory nerve is routinely used. Good elbow function can be expected in over 90 %. In C5/C6/C7 lesions, there are only slightly inferior results. In both groups there is a significant functional improvement by secondary tendon transfer at the age of two to three years. In the rare C5 - Th1 lesions, the functional results depend on the number and quality of the remaining roots. CONCLUSIONS: Provided there is good patient selection, severe obstetrical brachial plexus injuries should be scheduled for early microsurgical revision. There is no need to wait for a frustrating spontaneous recovery.

Adolescent↗
PubMed2005

"Lineage addiction" in human cancer: lessons from integrated genomics.

Genome-era advances in the field of oncology endorse the notion that many tumors may prove vulnerable to targeted therapeutic avenues once their salient molecular alterations are elucidated. Accomplishing this requires both detailed genomic characterization and the ability to identify in situ the critical dependencies operant within individual tumors. To this end, DNA microarray platforms such as high-density single-nucleotide polymorphism (SNP) arrays enable large-scale cancer genome characterization, including copy number and loss-of-heterozygosity analyses at high resolution. Clustering analyses of SNP array data from a large collection of tumor samples and cell lines suggest that certain copy number alterations correlate strongly with the tissue of origin. Such lineage-restricted alterations may harbor novel cancer genes directing genesis or progression of tumors from distinct tissue types. We have explored this notion through combined analysis of genome-scale data sets from the NCI60 cancer cell line collection. Here, several melanoma cell lines clustered on the basis of increased dosage at a region of chromosome 3p containing the master melanocyte regulator MITF. Combined analysis of gene expression data and additional functional studies established MITF as an amplified oncogene in melanoma. MITF may therefore represent a nodal point within a critical lineage survival pathway operant in a subset of melanomas. These findings suggest that, like oncogene addiction, "lineage addiction" may represent a fundamental tumor survival mechanism with important therapeutic implications.

Chromosomes, Human, Pair 3↗
PubMed2004

Cholesterol-lowering properties of Ganoderma lucidum in vitro, ex vivo, and in hamsters and minipigs.

INTRODUCTION: There has been renewed interest in mushroom medicinal properties. We studied cholesterol lowering properties of Ganoderma lucidum (Gl), a renowned medicinal species. RESULTS: Organic fractions containing oxygenated lanosterol derivatives inhibited cholesterol synthesis in T9A4 hepatocytes. In hamsters, 5% Gl did not effect LDL; but decreased total cholesterol (TC) 9.8%, and HDL 11.2%. Gl (2.5 and 5%) had effects on several fecal neutral sterols and bile acids. Both Gl doses reduced hepatic microsomal ex-vivo HMG-CoA reductase activity. In minipigs, 2.5 Gl decreased TC, LDL- and HDL cholesterol 20, 27, and 18%, respectively (P < 0.05); increased fecal cholestanol and coprostanol; and decreased cholate. CONCLUSIONS: Overall, Gl has potential to reduce LDL cholesterol in vivo through various mechanisms. Next steps are to: fully characterize bioactive components in lipid soluble/insoluble fractions; evaluate bioactivity of isolated fractions; and examine human cholesterol lowering properties. Innovative new cholesterol-lowering foods and medicines containing Gl are envisioned.

Journal Article↗
PubMed2004

Severe acute respiratory syndrome (SARS)--paradigm of an emerging viral infection.

An acute and often severe respiratory illness emerged in southern China in late 2002 and rapidly spread to different areas of the Far East as well as several countries around the globe. When the outbreak of this apparently novel infectious disease termed severe acute respiratory syndrome (SARS) came to an end in July 2003, it had caused over 8000 probable cases worldwide and more than 700 deaths. Starting in March 2003, the World Health Organization (WHO) organised an unprecedented international effort by leading laboratories working together to find the causative agent. Little more than one week later, three research groups from this WHO-coordinated network simultaneously found evidence of a hitherto unknown coronavirus in SARS patients, using different approaches. After Koch's postulates had been fulfilled, WHO officially declared on 16 April 2003 that this virus never before seen in humans is the cause of SARS. Ever since, progress around SARS-associated coronavirus (SARS-CoV) has been swift. Within weeks of the first isolate being obtained, its complete genome was sequenced. Diagnostic tests based on the detection of SARS-CoV RNA were developed and made available freely and widely; nevertheless the SARS case definition still remains based on clinical and epidemiological criteria. The agent's environmental stability, methods suitable for inactivation and disinfection, and potential antiviral compounds have been studied, and development of vaccines and immunotherapeutics is ongoing. Despite its grave consequences in humanitarian, political and economic terms, SARS may serve as an example of how much can be achieved through a well-coordinated international approach, combining the latest technological advances of molecular virology with more "traditional" techniques carried out to an excellent standard.

Antiviral Agents↗
PubMed2004

Effect of free plant sterols in low-fat milk on serum lipid profile in hypercholesterolemic subjects.

OBJECTIVE: To determine the effect of nonesterified, nonhydrogenated plant sterols solubilized in a partly vegetable oil-filled low-fat milk on serum low-density lipoprotein cholesterol (LDL) in mildly hypercholesterolemic patients. DESIGN: Double-blind, randomized, placebo-controlled three-arm crossover study. SETTING: Outpatient clinical trial. SUBJECTS: A total of 138 patients were screened, providing 81 patients for randomization; 71 patients completed the study. INTERVENTIONS: The study product was a 500 ml milk blend with or without nonesterified, nonhydrogenated sterols. The daily consumption of sterols in the three groups was 0 g/day, control group (C); 1.2 g/day, (Lo); or 1.6 g/day, (Hi), respectively. The patients were randomly assigned to one of three different treatment sequences. Each intervention period was 4 weeks. The total study duration was 12 weeks. RESULTS: The milk product was well tolerated. The placebo-adjusted mean reduction in LDL was 7.13+/-12.31 and 9.59+/-12.44% (mean+/-s.d.) for Lo and Hi groups, respectively (P<0.0001); there was no statistically significant difference in LDL lowering for the Lo and Hi groups. There were no significant changes in serum vitamin E or carotenoid concentrations after standardization with LDL cholesterol during the study period. CONCLUSION: The present study shows for the first time a substantial reduction in LDL cholesterol with a new, partly vegetable oil-filled 1.2% low-fat milk product, containing nonesterified plant sterols from soybean oil, in a randomized, placebo-controlled trial. This result encourages further development of novel low-fat dairy products containing free plant sterols for future use in cholesterol-lowering initiatives.

Aged↗
PubMed2004

Evaluation of an amikacin loading dose for nosocomial infections in very low birthweight infants.

AIM: To develop a simplified amikacin dosage regimen for nosocomial infections in preterm infants including a loading dose in order to achieve therapeutic Maximum Serum Concentrations early in the course of therapy. METHODS: Open, non-comparative study during November 2000 to April 2001. The modified amikacin dosing and monitoring protocol included a loading dose of 10 mg/kg in the first week of life, followed by a maintenance regimen of 7.5 mg/kg every 24 h. After the first week of life the corresponding doses were 17 mg/kg (loading) and 15 mg/kg (maintenance). A peak level was measured 30 min after the second dose, a trough level immediately before the third dose. RESULTS: Twenty-five very low birthweight infants (median birthweight 739 g, median gestational age 25 wk) who had 34 episodes of amikacin treatment were included in the analysis. Median amikacin peak and trough values were 37.1 micromol/l and 6.3 micromol/l, respectively. Twenty-nine of all peak levels (85%) and 30 of all trough levels (88%) were within the targeted range of >35 micromol/l and <8.5 micromol/l, respectively. All patients with elevated trough levels were of extremely low birthweight and were born in the 24th week of gestation. Hearing evaluations were performed in 17 of 19 surviving infants at discharge home, all of which gave normal results. CONCLUSION: The new amikacin dosing protocol yielded targeted peak and trough concentrations in a high percentage of very low birthweight infants with nosocomial infection after the first week of life. Our simplified dosage regimen achieved acceptable serum concentrations in all birthweight and gestational age groups, with the exception of extremely low birthweight infants weighing less than 700 g and/or with a gestational age of 24 wk or less. Only limited information can be gained from our data regarding the use of amikacin during the first week of life.

Amikacin↗
PubMed2004

Safety evaluation of piperacillin/tazobactam in very low birth weight infants.

An open, non-comparative study was designed to evaluate the safety and tolerance of parenteral piperacillin/tazobactam in very low birth weight infants. Twenty-seven patients were included for nosocomial sepsis with gram-negative bacteria (n = 4), nosocomial sepsis not responding to the empirical antibiotic regimen (n = 3), suspected necrotizing enterocolitis (n = 17), and infection after abdominal surgery for reasons other than necrotizing enterocolitis (n = 3). No clinical adverse events considered related to the study drug were noted, in particular, no cases of phlebitis, rash or stool changes. Several possibly related, mild and transitory abnormalities of laboratory parameters were observed. No long-lasting effect on the intestinal flora was detected. Seventeen patients (63%) were considered to have a favorable clinical response. This study demonstrates that piperacillin/tazobactam is a safe and well tolerated drug for preterm infants with bacterial infections, particularly those involving the gastrointestinal tract. Comparative clinical trials are warranted to further clarify the microbiological efficacy of piperacillin/tazobactam in this particular patient population.

Anti-Bacterial Agents↗
PubMed2003

Identification and fine mapping of Pi33, the rice resistance gene corresponding to the Magnaporthe grisea avirulence gene ACE1.

Rice blast disease is a major constraint for rice breeding. Nevertheless, the genetic basis of resistance remains poorly understood for most rice varieties, and new resistance genes remain to be identified. We identified the resistance gene corresponding to the cloned avirulence gene ACE1 using pairs of isogenic strains of Magnaporthe grisea differing only by their ACE1 allele. This resistance gene was mapped on the short arm of rice chromosome 8 using progenies from the crosses IR64 (resistant) x Azucena (susceptible) and Azucena x Bala (resistant). The isogenic strains also permitted the detection of this resistance gene in several rice varieties, including the differential isogenic line C101LAC. Allelism tests permitted us to distinguish this gene from two other resistance genes [ Pi11 and Pi-29(t)] that are present on the short arm of chromosome 8. Segregation analysis in F(2) populations was in agreement with the existence of a single dominant gene, designated as Pi33. Finally, Pi33 was finely mapped between two molecular markers of the rice genetic map that are separated by a distance of 1.6 cM. Detection of Pi33 in different semi-dwarf indica varieties indicated that this gene could originate from either one or a few varieties.

Chromosome Mapping↗
PubMed2003

Fine genetic mapping of a gene required for Rice yellow mottle virus cell-to-cell movement.

The very high resistance to Rice yellow mottle virus observed in the two rice varieties Gigante ( Oryza sativa) and Tog 5681 ( O. glaberrima) is monogenic and recessive. Bulked segregant analysis was carried out to identify AFLP markers linked to the resistance gene. Mapping of PCR-specific markers, CAPS and microsatellite markers on 429 individuals of an IR64 x Gigante F(2) population pinpointed this resistance gene on the long arm of chromosome 4 in a 3.7-cM interval spanned by PCR markers. These markers also flanked the resistance gene of the O. glaberrima accession Tog 5681 and confirmed previous allelism tests. The rarity of this recessive natural resistance was in line with a resistance mechanism model based on point mutations of a host component required for cell-to-cell movement of the virus. Preliminary data on the genetic divergence between the two cultivated rice species in the vicinity of the resistance locus suggested that two different resistance alleles are present in Gigante and Tog 5681. A large set of recombinants is now available to envisage physical mapping and cloning of the gene.

Chromosome Mapping↗