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Biomedical subjects

A Hagen

Publications and source records attributed to A Hagen.

At least 19 recordsLinked to original sources
PubMed2006

Early diagnosis of conjoined twins by real-time three-dimensional ultrasound--case report and review of the literature.

In 1:50 000 to 1:100 000 births, conjoined twins occur, caused by incomplete division of the embryonic disc more than 13 days after fertilisation. We present a case of cephalothoracopagus janiceps, a very rare form of conjoined twins, which was diagnosed at 13 weeks of gestation. Three-dimensional and colour Doppler ultrasound enabled precise prenatal visualisation of the fusion of the foetal head and chest up to the umbilicus. We could demonstrate the presence of two foetal hearts connected by an arterio-arterial shunt as well as two pairs of upper and lower extremities. After the clear 3-D presentation of the anomaly, making the poor prognosis visible, the mother decided to have the pregnancy terminated. Autopsy confirmed the prenatal diagnosis.

Adult↗
PubMed2006

Ultrafast dynamics of delocalized and localized electrons in carbon nanotubes.

We report on the dynamics of the dielectric function of single-wall carbon nanotubes in the 10-30 THz frequency range after ultrafast laser excitation. The absence of a distinct free-carrier response is attributed to the photogeneration of strongly bound excitons in the tubes with large energy gaps. We find a feature of enhanced transmission caused by the blocking of optical transitions in small-gap tubes. The rapid decay of a featureless background with pronounced dichroism is associated with the increased absorption of spatially localized charge carriers before thermalization is completed.

Journal Article↗
PubMed2004

[The technique of outflow tract reconstruction in patients with tetralogy of Fallot influence the morbidity 3 decades after repair].

The purpose of this study was to examine long-term results of different surgical techniques in patients with tetralogy of Fallot considering their morbidity. We analyzed the data of 74 patients 24.5 +/- 3 years after surgical repair in childhood to evaluate their clinical status, maximal exercise capacity, medication and frequency of reoperations. We compared two groups of patients according to the surgical techniques employed: 1) TAP group (Trans anular Patch, n = 41) in which ventricular septal defects were closed with a Dacron patch, the right ventricular outflow was reconstructed by resection of the partial extension of the infundibular septum and transanular patch repair was performed because of hypoplastic pulmonary valve. 2) nonTAP group (33) in which no transanular patch repair was necessary. Most of the patients described their health as "good". 94% of the nonTAP group and 71% of TAP group were in NYHA class I. The rest were in NYHA class II. Despite the good clinical classification we found a reduced cardiopulmonary exercise capacity in all patients. More than 50% in the TAP group took medicine because of congestive heart failure and/or arrhythmia, which was present 3-times more often compared with the nonTAP group. Furthermore, 50% of TAP group patients had at least one reoperation during the follow- up: by comparison 5-times more often than the nonTAP group. These data show that the long-term outcome and morbidity of the patients after repair is closely related to the type of the surgical technique employed.

Adolescent↗
PubMed2003

Epignathus: always a simple teratoma? Report of an exceptional case with two additional fetiforme bodies.

We report on a case of a fetal epignathus combined with two fetus-like structures resembling acardius acranius. The anomaly was detected at 23 weeks of gestation and led to termination of pregnancy at 24 weeks. This is the first description of epignathus with parasitic fetuses detected prenatally. It shows that the boundary between fetal teratoma and multiple pregnancy in special cases may be difficult to define.

Abnormalities, Multiple↗
PubMed2003

Cell therapy using encapsulated cells producing endostatin.

Despite aggressive surgery and post-operative radiation and chemotherapy, the prognosis is poor for glioblastoma patients. Anti-angiogenic therapy with compounds such as endostatin could delay the onset of relapse. However, the short systemic half-life of this proteins as well as the blood-brain barrier makes the use of this therapy difficult for brain cancer patients. The aim of this project is to develop and implant genetically engineered producer cells secreting endostatin that are encapsulated in calcium cross-linked alginate gel beads. Encapsulation of cells within alginate gels has a potential as a sustained release system in addition to the fact that the encapsulation technology protects the cells from rejection by the immune system. Human embryonal kidney 293 cells have been transfected with the gene for endostatin. These cells have been encapsulated in calcium cross-linked alginate gels and optimized for the secretion of endostatin. Alginate gel beads implanted into rat brain have shown only a moderate loss in cell viability but extended endostatin release for periods of up to 12 months. Visualization of the anti-angiogenic effect on C6 rat glioma growth, tumor vasculature and microhemodynamics has been demonstrated by using intravital video microscopy. The data indicates that endostatin greatly affects tumor-associated microcirculation but does not appear to affect normal microcirculation. The local delivery of endostatin seems to specifically affect tumor-associated microvessels by reduction of the vessel density, diameter and functionality. Tumor cell migration and invasion was greatly reduced in the endostatin treated animals.

Alginates↗
PubMed2002

Specific developmental gene silencing in the honey bee using a homeobox motif.

Manipulating the expression of genes in species that are not currently used as genetic models will provide comparative insights into the evolution of gene functions. However the experimental tools in doing so are limited in species that have not served as models for genetic studies. We have examined the effects of double stranded RNA (dsRNA) in the honey bee, an insect with considerably basic scientific interest. dsRNA derived from a 300 bp stretch of the E30 homeobox motif was injected into honey bee embryos at the anterior pole in the preblastoderm stage. We found that the dsRNA fragment successfully disrupted the protein expression of the target gene throughout the whole embryo. The disruption caused deficient phenotypes similar to known loss of function mutants of Drosophila engrailed, whereas embryos injected with nonsense dsRNA showed no abnormalities. We show that the large size of the honey bee egg (D: 0.3 mm, L: 1.6 mm) and the long preblastoderm stage (11-12 h) can be exploited to generate embryos with partial disruption of gene function, which may provide an elegant alternative to classical chimeric analyses. This is the first report of targeted disruption of gene function in the honey bee, and the results prove that the chosen target gene is a functional ortholog to engrailed in Drosophila.

Animals↗
PubMed2001

Genetic epidemiology of BRCA1 mutations in Norway.

Familial breast-ovarian cancer has been demonstrated to be frequent but unevenly distributed in Norway. This was assumed to be caused by the reduced population size created by the medieval Bubonic plagues 25 generations ago, and by the following rapid expansion. We have previously reported that four mutations account for 68% of the BRCA1 mutation carriers. Subsequent analysis has resulted in a total of 100 separate families carrying one of these founder mutations. The four mutations occurred on one specific BRCA1 haplotype each. The 1675delA, 816delGT and 3347delAG families originated from the South-West coast of Norway with a few families in the north, while the traceable ancestors of the 1135insA families clustered along the historical inland road from the South-East to mid-Norway. The carriers of each of the four mutations today are descendants of one or a few individuals surviving the plagues. We may identify the majority of BRCA1 mutation carriers in Norway by screening for local founder mutations.

Breast Neoplasms↗
PubMed2001

[The impact of pregnancy-prolonging management on maternal and neonatal morbidity in HELLP syndrome].

OBJECTIVE: Until recently, delivery immediately after diagnosing HELLP syndrome was recommended due to the life-threatening risk to mother and child. Prolongation at least until lung maturation is being increasingly considered because of the high rate of premature births characterized by extreme immaturity. We investigated the influence of the time of delivery on maternal and neonatal morbidity at a gestational age of less than 34 + 0 weeks of pregnancy. - MATERIAL AND METHODS: The disease course was reevaluated in 37 patients who developed HELLP syndrome (thrombocytes < 100 000/microl, transaminase > 70 U/l, haptoglobin < 0.5 g/l) between 1994 and 1999. An attempt was made to stabilize the mother's condition under therapeutic volume expansion. Pregnancy was terminated with the onset of a renewed HELLP episode. - RESULTS: HELLP syndrome occurred with an incidence of 1 : 310 births. There were no maternal or neonatal deaths or any severe complications. Prolonging pregnancy until completing drug-induced lung maturity was successful in 16 of 25 patients before the 34(th) week of pregnancy. In the case of immediate delivery with inadequate stabilization, 5 of 9 patients had postpartum complications. A severe RDS occurred in 3 premature babies without drug-induced maturity. - CONCLUSION: If there is no life-threatening risk to the fetus or mother in patients with HELLP syndrome, the objective is the prolongation of pregnancy in a perinatal center until lung maturation. Stabilization is successful in a high percentage of patients under therapeutic volume expansion with optimal monitoring of mother and child.

Adult↗
PubMed2001

The potential for aromatase inhibition in breast cancer prevention.

Although SERMs are currently being evaluated and are approved for breast cancer prevention in several countries, aromatase inhibitors and inactivators may represent interesting options in this setting. The encouraging results revealing these drugs to be superior to conventional therapy in metastatic breast cancer confirm their therapy efficacy and suggest that they may also have a role in adjuvant therapy and even for breast cancer prevention. Secondly, whereas the bulk of "high-risk" breast cancer patients with confirmed founder mutations in the BRCA1 or BRCA2 genes develop their cancers earlier in life (during the premenopausal period), 75-80% of all breast cancers, in general, develop in postmenopausal women. Thus, in considering prevention of breast cancer in moderate-risk groups, strategies for prevention in postmenopausal women may play an important role. Also, among high-risk patients who have not developed breast cancer by the time of the menopause, aromatase inhibition could be a feasible option. Considering the potential hazards of long-term use of SERMs, switching to an aromatase inhibitor or inactivator in this setting may be beneficial. Finally, the observation that postmenopausal estrogen levels are related to subsequent risk of breast cancer in the general population underlines the potential for estrogen suppression as a preventive strategy. Results from ongoing studies examining the toxicity of aromatase inhibitors and inactivators in postmenopausal women will set the stage for future trials that explore them as preventive treatment options.

Anticarcinogenic Agents↗
PubMed1998

Hyperemesis in late pregnancy--should we think of cancer? A case report.

Gastric cancer is unusual during pregnancy. The diagnosis may be delayed because specific symptoms are similar to typical pregnancy associated complaints. Our therapeutic management with palliative chemotherapy and later gastrectomy differs from other known cases, where surgical resection has been the treatment of choice. Surgery appears to have no influence on the prognosis of gastric cancer patients with hepatic metastases.

Adult↗
PubMed1998

Centralization of low back pain and perceived functional outcome.

McKenzie's methods for evaluating and treating low back pain are used often but studied little. When using the McKenzie system, it is important to observe signs of symptom movement to a central location (centralization). This study investigated the relationships between centralization of low back pain and/or radiculopathy and the subjects' rating of functional outcome. Thirty-six subjects with low back pain volunteered to participate and were evaluated and treated by six researchers. Subjects were tested initially and again 14 days after initiation of treatment using the Oswestry Low Back Pain Disability Questionnaire and the Performance Assessment and Capacity Testing Spinal Function Sort (SFS). Symptoms were monitored for the occurrence of "complete centralization." Of the 36 subjects, 25 showed complete centralization within 14 days. The SFS score changes were significantly higher for subjects who completely centralized (p = 0.015). The results supported the hypothesis that subjects who centralize will have improved functional outcome and, thus, quality of life. However, shorter time to occurrence of complete centralization does not necessarily correlate with improved outcome.

Adult↗
PubMed1996

[ECG abnormalities in Airedale terriers].

Because of bradyarrhythmic complications under anesthesia in two Airedale Terriers, we performed a prospective search of ECG-abnormalities in healthy dogs of that breed. Resting ECG's were screened for routine abnormalities. None of the 42 dogs investigated so far had a completely normal ECG. Among the common abnormalities were: deviation of the mean electrical axis (MEA) in 32 dogs, low voltage QRS-complexes in 22 dogs, and AV-blocks 1st degree in 14 dogs. None of the recorded abnormalities with the exception of AV-blocks, were considered predictors of anesthetic complications. Because of the high frequency of recorded abnormalities, we are continuing this prospective study.

Anesthesia↗