Fetal lung growth in experimental utero-abdominal pregnancy

We removed rat fetuses from the uterus without disturbing the placental implantation site, placing the fetuses in the peritoneal cavity either within intact membranes (with or without amniotic fluid) or outside of the fetal membranes. Untouched littermate fetuses served as controls. The surgery was performed on day 17 of gestation and the outcome was analyzed at term, 4 days later. The utero-abdominal pregnancies with intact membranes and amniotic fluid yielded fetuses in all respects indistinguishable from littermate controls. Extrauterine fetuses maintained within their membranes but without amniotic fluid as well as extrauterine and extramembranous fetuses displayed identical features: body weight was slightly reduced; after correction for body weight, only their lungs weighed significantly less and contained less deoxyribonucleic acid. In addition, fetuses in these two groups had multiple joint contractures and occasional webbing of the skin. These experimental findings in rats indicate an important role of amniotic fluid in fetal development, especially of the lung.     

High-dose Remifentanil Does Not Impair Cerebrovascular Carbon Dioxide Reactivity in Healthy Male Volunteers

Background: Cerebrovascular carbon dioxide reactivity during high-dose remifentanil infusion was investigated in volunteers by measurement of regional cerebral blood flow (rCBF) and mean CBF velocity (CBFv).

Methods: Ten healthy male volunteers with a laryngeal mask for artificial ventilation received remifentanil at an infusion rate of 2 and 4 [mu]g [middle dot] kg-1 [middle dot] min-1 under normocapnia, hypocapnia, and hypercapnia. Stable xenon-enhanced computed tomography and transcranial Doppler ultrasonography of the left middle cerebral artery were used to assess rCBF and mean CBFv, respectively. If required, blood pressure was maintained within baseline values with intravenous phenylephrine to avoid confounding effects of altered hemodynamics.

Results: Hemodynamic parameters were maintained constant over time. Remifentanil infusion at 2 and 4 [mu]g [middle dot] kg-1 [middle dot] min-1 significantly decreased rCBF and mean CBFv. Both rCBF and mean CBFv increased as the arterial carbon dioxide tension increased from hypocapnia to hypercapnia, indicating that cerebrovascular reactivity remained intact. The average slopes of rCBF reactivity were 0.56 +/- 0.27 and 0.49 +/- 0.28 ml [middle dot] 100 g-1 [middle dot] min-1 [middle dot] mmHg-1 for 2 and 4 [mu]g[middle dot]kg-1[middle dot]min-1 remifentanil, respectively (relative change in percent/mmHg: 1.9 +/- 0.8 and 1.6 +/- 0.5, respectively). The average slopes for mean CBFv reactivity were 1.61 +/- 0.95 and 1.54 +/- 0.83 cm [middle dot] s-1 [middle dot] mmHg-1 for 2 and 4 [mu]g [middle dot] kg-1 [middle dot] min-1 remifentanil, respectively (relative change in percent/mmHg: 1.86 +/- 0.59 and 1.79 +/- 0.59, respectively). Preanesthesia and postanesthesia values of rCBF and mean CBFv did not differ.     

Preventive effects of diltiazem on cyclosporin A-induced vascular smooth muscle dysfunction

Cyclosporin A may cause vascular smooth muscle dysfunction due to calcium overload as a consequence of chronically augmented calcium influx. In the present study, the responsiveness to vasoconstrictors was investigated in rats after chronic treatment for 6 weeks with placebo, cyclosporin A (30 mg/kg per day), diltiazem (60 mg/kg per day), or cyclosporin A plus diltiazem. Twenty-four hours after the last oral treatment the animals were sacrified and rings of the thoracic aorta were suspended in organ chambers under isometric conditions in the absence of cyclosporin A or diltiazem. Chronic treatment with cyclosporin A significantly augmented contractions to angiotensin II (10^-9–10^-5 M). This effect was prevented by cotreatment with diltiazem. Diltiazem did not affect the cyclosporin A-induced reduction in the response to potassium chloride (10–80 mM). The contractions to phenylephrine (10^-9–10^-6 M) and endothelin-1 (10^-9–10^-7 M) were not significantly different in the four groups. The preventive effect of diltiazem against the cyclosporin A-induced hypersensitivity to angiotensin II supports the hypothesis of increased calcium influx during cyclosporin A therapy. The results may provide an additional rationale for the use of calcium antagonists in the treatment of the vascular side effects of cyclosporin A.     

Combined endurance and muscle strength training in female and male patients with chronic heart failure

BACKGROUND: Exercise training has now become established practice in patients with chronic heart failure. Women are often under-represented in intervention studies compared to men. For this reason it was our aim to conduct a combined endurance and muscle strength training program to evaluate its effect on clinical performance data and health-related psychosocial factors in women and men. METHODS: One hundred and sixteen women, mean age 69 +/- 9 years, body mass index (BMI) 25.8 +/- 4.9, and 169 men, mean age 66 +/- 9 years, BMI 26.6 +/- 3.6 underwent combined endurance/resistance training. The training program lasted 29 +/- 7 days and comprised bicycle ergometer training, a 6-min walk test as a training unit and muscle strength training for the lower and upper extremities. RESULTS: Differences between women and men were found in clinical parameters. In particular, statistically significant differences were revealed between the women and men with regard to cardiopulmonary performance. Quality of life was significantly improved on discharge with regard to both physical and mental health, whereas anxiety and depression showed no significant alteration. CONCLUSION: A specialized in-hospital program for women and men combining endurance/resistance training and education is feasible. But our program revealed a very low level of cardiopulmonary performance in women. Women need to be encouraged and motivated to participate in such programs.     

Improved assessment of intravascular Doppler coronary flow velocity profile

Easy and safe in- vivo flow velocity studies in small coronary arteries have become feasible using a 0.014 ‘ or 0.018 ’ guidewire with an integrated Doppler probe in its tip (FloWire, Cardiometrics). Assessment of the flow velocity profile by the ratio of diastolic to systolic flow velocity (DSVR) is used as a diagnostic parameter. However, DSVR is a coarse quantifier of the flow velocity profile, and is subject to large physiologic variance and depends crucially on the quality of the Doppler signal. The aim of our study was to test parameters derived from statistical time series analysis for monitoring the quality of the instantaneous peak velocity (IPV) signal. Improvement of quantification of changes in quality and shape of flow velocity profiles by these parameters as compared to DSVR was a second goal. We investigated analog-digital converted IPV- signals and video registrations of corresponding greyscale spectra of intracoronary Doppler flow velocity signals. The signals were analyzed by using the autocorrelation function (ACF) in the time domain and a fast Fourier transform (FFT) in the frequency domain (standard time series statistics). The first minimum of autocorrelation function turned out to be very sensitive to signal quality, and Fisher's g of the periodogram was the parameter of choice for shape analysis. In 11 patients with coronary artery disease, pre and post PTCA, the sensitivity of DSVR and signal to noise ratio to changes in shape and quality of the flow velocity signals was compared to that of the new parameters. Nineteen Doppler flow velocity samples of good quality from measurements in nonstenotic vessels and 7 flow velocity tracings with visible artefacts were used to assess the value of these parameters in monitoring signal quality. By comparison with corresponding parameters in use (SNR and DSVR) a significantly improved performance of the new statistical parameters was observed with respect to sensitivity to changes in signal quality and flow profile. In view of these results and because of the short calculation time of these variables they should be used for on-line quality control and analysis of flow velocity profiles.     

Sensory motor retuning: a behavioral treatment for focal hand dystonia of pianists and guitarists

OBJECTIVE: To evaluate the long-term effectiveness of sensory motor retuning (SMR), a new treatment for focal hand dystonia in musicians. DESIGN: Prospective case series with an (adventitious) comparison group with 3- to 25-month follow-up in piano and guitar and 0- to 4-month follow-up in flute and oboe players. SETTING: General community in Germany. PARTICIPANTS: Eleven professional musicians. INTERVENTION: Immobilization by splints of 1 or more digits other than the focal dystonic finger. This finger carried out repetitive exercises in coordination with 1 or more of the other digits for 1(1/2) to 2(1/2) hours a day for 8 consecutive days under therapist supervision. The subjects then were instructed to continue practice for 1 hour daily for 1 year. MAIN OUTCOME MEASURES: Spectral analysis of the output of a dexterity-displacement device that continuously recorded digital displacement during finger movements and a dystonia evaluation scale on which patients rated how well they had just performed dystonic movement sequences and repertoire passages. RESULTS: The 3 wind players (adventitious placebo controls) did not improve substantially. However, each pianist and guitarist showed marked and significant improvement in spontaneous repertoire performance without the splint. The first subject is now 25 months posttreatment. CONCLUSIONS: Results suggest that SMR is of value for the treatment of focal hand dystonia in pianists and guitarists.     

Effects of selenium deficiency on the rat myocardial protein pattern – investigation by two-dimensional gel electrophoresis

Dietary selenium deficiency represents an etiological factor in “Keshan disease”, a distinct form of an endemic cardiomyopathy. The biochemical effects of selenium depletion in the myocardium are, however, not yet known. Therefore, we investigated the changes in the myocardial protein pattern in rats after long-term selenium deficiency. The myocardial proteins were analyzed in samples from five selenium-depleted rats (Se-deficient group) and five rats supplied with adequate amounts of the element (Se-adequate group). Isoelectric focusing (IEF) with carrier ampholytes on large 2-DE gels was used for the separation of proteins in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for the second dimension. The protein patterns were evaluated by means of a computer-assisted gel analysis system. The biochemical identification of the proteins of interest was achieved by matrix-assisted laser desorption/ionization mass spectrometry (MALDI) or immunoblotting. On average, 588 ± 68 protein spots were found on the gels. No significant difference in spot numbers existed between the groups. A pattern of 270 spots with identical positions was found on every gel; 247 of these spots were not saturated and used for quantitative comparison. Thirty-five, i. e., 14%, differed significantly in their relative intensity in the two groups. Twenty-eight protein spots were decreased in the Se-deficient group and seven were increased. Sarcomeric creatine kinase M chain, α-myosin heavy chain (α-MHC) and myosin light chain 1 and 2 (MLC 1 and 2) were largely decreased in Se-deficiency. Three protein spots were increased by more than twofold or appeared only in the Se-deficient group. A mitochondrial creatine kinase was identified in this group. The results suggest that selenium deficiency affects myocardial energy metabolism and contractile proteins. These changes probably reflect non-specific alterations in heart failure. Received: 19 February 1997, Returned for 1. revision: 7 April 1997, 1. Revision received: 29 January 1999, Returned for 2. revision: 18 February 1999, 2. Revision received: 21 December 1999, Accepted: 6 January 2000     

Gene amplification during differentiation of mammalian neural stem cells in vitro and in vivo

In development of amphibians and flies, gene amplification is one of mechanisms to increase gene expression. In mammalian cells, gene amplification seems to be restricted to tumorigenesis and acquiring of drug-resistance in cancer cells. Here, we report a complex gene amplification pattern in mouse neural progenitor cells during differentiation with approximately 10% of the genome involved. Half of the amplified mouse chromosome regions overlap with amplified regions previously reported in human neural progenitor cells, indicating conserved mechanisms during differentiation. Using fluorescence in situ hybridization, we verified the amplification in single cells of primary mouse mesencephalon E14 (embryonic stage) neurosphere cells during differentiation. In vivo we confirmed gene amplifications of the TRP53 gene in cryosections from mouse embryos at stage E11.5. Gene amplification is not only a cancer-related mechanism but is also conserved in evolution, occurring during differentiation of mammalian neural stem cells     

New insights into the genetics of glioblastoma multiforme by familial exome sequencing

Glioblastoma multiforme (GBM) is the most aggressive and malignant subtype of human brain tumors. While a family clustering of GBM has long been acknowledged, relevant hereditary factors still remained elusive. Exome sequencing of families offers the option to discover respective genetic factors.We sequenced blood samples of one of the rare affected families: while both parents were healthy, both children were diagnosed with GBM. We report 85 homozygous non-synonymous single nucleotide variations (SNVs) in both siblings that were heterozygous in the parents. Beyond known key players for GBM such as ERBB2, PMS2, or CHI3L1, we identified over 50 genes that have not been associated to GBM so far. We also discovered three accumulative effects potentially adding to the tumorigenesis in the siblings: a clustering of multiple variants in single genes (e.g. PTPRB, CROCC), the aggregation of affected genes on specific molecular pathways (e.g. Focal adhesion or ECM receptor interaction) and genomic proximity (e.g. chr22.q12.2, chr1.p36.33). We found a striking accumulation of SNVs in specific genes for the daughter, who developed not only a GBM at the age of 12 years but was subsequently diagnosed with a pilocytic astrocytoma, a common acute lymphatic leukemia and a diffuse pontine glioma.The reported variants underline the relevance of genetic predisposition and cancer development in this family and demonstrate that GBM has a complex and heterogeneous genetic background. Sequencing of other affected families will help to further narrow down the driving genetic causes for this disease.