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1.
Nature ; 613(7944): 503-507, 2023 01.
Article in English | MEDLINE | ID: mdl-36653569

ABSTRACT

The Greenland Ice Sheet has a central role in the global climate system owing to its size, radiative effects and freshwater storage, and as a potential tipping point1. Weather stations show that the coastal regions are warming2, but the imprint of global warming in the central part of the ice sheet is unclear, owing to missing long-term observations. Current ice-core-based temperature reconstructions3-5 are ambiguous with respect to isolating global warming signatures from natural variability, because they are too noisy and do not include the most recent decades. By systematically redrilling ice cores, we created a high-quality reconstruction of central and north Greenland temperatures from AD 1000 until 2011. Here we show that the warming in the recent reconstructed decade exceeds the range of the pre-industrial temperature variability in the past millennium with virtual certainty (P < 0.001) and is on average 1.5 ± 0.4 degrees Celsius (1 standard error) warmer than the twentieth century. Our findings suggest that these exceptional temperatures arise from the superposition of natural variability with a long-term warming trend, apparent since AD 1800. The disproportionate warming is accompanied by enhanced Greenland meltwater run-off, implying that anthropogenic influence has also arrived in central and north Greenland, which might further accelerate the overall Greenland mass loss.


Subject(s)
Climate , Global Warming , Temperature , Global Warming/statistics & numerical data , Greenland , Ice Cover , Human Activities/trends , Water Movements , Freezing
2.
AJNR Am J Neuroradiol ; 43(2): 223-229, 2022 02.
Article in English | MEDLINE | ID: mdl-34969666

ABSTRACT

BACKGROUND AND PURPOSE: The Normal Pressure Hydrocephalus Radscale is a combined scoring of 7 different structural imaging markers on preoperative brain CT or MR imaging in patients with idiopathic normal pressure hydrocephalus: callosal angle, Evans Index, Sylvian fissure dilation, apical sulcal narrowing, mean temporal horn diameter, periventricular WM lesions, and focal sulcal dilation. The purpose of this retrospective study was to assess the performance of the Normal Pressure Hydrocephalus Radscale in distinguishing idiopathic normal pressure hydrocephalus shunt responders from nonresponders. MATERIALS AND METHODS: The preoperative MR imaging and CT scans of 119 patients with idiopathic normal pressure hydrocephalus were scored using the Normal Pressure Hydrocephalus Radscale. A summary shunt-response score assessed within 6 months from ventriculoperitoneal shunt surgery, combining the effect on cognition, gait, and urinary incontinence, was used as a reference. The difference between the mean Normal Pressure Hydrocephalus Radscale for responders and nonresponders was tested using the Student t test. The area under the curve was calculated for the Normal Pressure Hydrocephalus Radscale to assess shunt response. To ascertain reproducibility, we assessed the interobserver agreement between the 2 independent observers as intraclass correlation coefficients for the Normal Pressure Hydrocephalus Radscale for 74 MR imaging scans and 19 CT scans. RESULTS: Ninety-four (79%) of 119 patients were shunt responders. The mean Normal Pressure Hydrocephalus Radscale score for shunt responders was 8.35 (SD, 1.53), and for nonresponders, 7.48 (SD, 1.53) (P = .02). The area under the curve for the Normal Pressure Hydrocephalus Radscale was 0.66 (range, 0.54-0.78). The intraclass correlation coefficient for the Normal Pressure Hydrocephalus Radscale was 0.86 for MR imaging and 0.82 for CT. CONCLUSIONS: The Normal Pressure Hydrocephalus Radscale showed moderate discrimination for shunt response but cannot, on its own, be used for selecting patients with idiopathic normal pressure hydrocephalus for shunt surgery.


Subject(s)
Hydrocephalus, Normal Pressure , Brain/diagnostic imaging , Brain/pathology , Brain/surgery , Humans , Hydrocephalus, Normal Pressure/complications , Hydrocephalus, Normal Pressure/diagnostic imaging , Hydrocephalus, Normal Pressure/surgery , Neuroimaging/methods , Reproducibility of Results , Retrospective Studies
3.
Biotechnol Bioeng ; 83(4): 376-85, 2003 Aug 20.
Article in English | MEDLINE | ID: mdl-12800132

ABSTRACT

A novel in situ product removal (ISPR) method that uses microcapsules to extract inhibitory products from the reaction suspension is introduced into fermentation technology. More specifically, L-phenylalanine (L-Phe) was transformed by Saccharomyces cerevisiae to 2-phenylethanol (PEA), which is inhibitory toward the yeast. In order to continuously remove PEA from the vicinity of the cells, the reaction suspension was brought into contact with capsules of 2.2-mm diameter that had a hydrophobic core of dibutyl sebacate and an alginate-based wall. This novel process combines the advantages of a normal in situ extraction process (fast mass transfer and simple process set-up) with the benefits of a membrane-based process (reduction of the solvent toxicity and avoidance of stable emulsions). In particular, the microbial cells are shielded from the phase toxicity of the organic solvent by a hydrogel layer surrounding the organic core. By placing the microcapsules into the fermenter, the final overall concentration of PEA in a fed-batch culture was increased from 3.8 to 5.6 g/L because a part of the inhibitory product dissolved in the dibutyl sebacate core. In another fermentation experiment, the capsules were placed in a fluidized bed that was connected via a loop to the fermenter. In addition, the fluidized bed was connected via a second loop to a back-extractor to regenerate the capsules. By alternating the extraction and back-extraction cycles, it was possible to limit the PEA concentration of the fed-batch culture in the fermenter to 2.4 g/L while producing important quantities of PEA that accumulated in an external reservoir.


Subject(s)
Cell Culture Techniques/methods , Dicarboxylic Acids/chemistry , Membranes, Artificial , Phenylalanine/metabolism , Phenylethyl Alcohol/isolation & purification , Phenylethyl Alcohol/metabolism , Saccharomyces cerevisiae/metabolism , Ultrafiltration/methods , Adsorption , Bioreactors , Cell Culture Techniques/instrumentation , Coated Materials, Biocompatible/chemical synthesis , Coated Materials, Biocompatible/chemistry , Microspheres , Phenylethyl Alcohol/chemistry , Saccharomyces cerevisiae/chemistry , Solvents/chemistry , Ultrafiltration/instrumentation
4.
Urologe A ; 42(3): 366-73, 2003 Mar.
Article in German | MEDLINE | ID: mdl-12671770

ABSTRACT

Since in the absence of clinically overt metastatic disease tumorous lesions within the adrenal gland are found in only 2-10% of cases, the majority of renal cell cancer patients are overtreated by adrenalectomy as an integral part of nephrectomy. The medical records of 847 patients undergoing adrenalectomy in combination with nephrectomy irrespective of the local extent of the primary tumor or the clinical stage at first diagnosis were reviewed to determine the reliability of currently available imaging modalities regarding the prediction of adrenal gland metastases. Several patient and tumor characteristics correlated with the presence of intra-adrenal metastases, and their prognostic value was determined by a multivariate logistic regression model. Metastatic spread into the adrenal gland was observed in 27 of 847 (3%) patients. In only three of eight patients in whom the adrenal was identified as the only metastatic site, preoperative abdominal CT scans were interpreted as false negative. During multivariate statistical analysis, only the presence of distant metastases, vascular invasion within the primary tumor, and multifocal growth of renal cell cancer within the tumor-bearing kidney were identified to independently predict the likelihood for the presence of intra-adrenal metastases. None of the patient or tumor characteristics evaluated reliably predicted the likelihood for the presence of adrenal metastases in patients without evidence of disseminated metastatic spread. As we believe and as the current investigation demonstrates, routine adrenalectomy should not be recommended in cases of preoperatively normal radiological examinations.


Subject(s)
Adrenal Gland Neoplasms/secondary , Adrenalectomy/statistics & numerical data , Carcinoma, Renal Cell/secondary , Kidney Neoplasms/surgery , Nephrectomy/statistics & numerical data , Adrenal Gland Neoplasms/epidemiology , Adrenal Gland Neoplasms/pathology , Adrenal Gland Neoplasms/surgery , Adrenal Glands/pathology , Carcinoma, Renal Cell/epidemiology , Carcinoma, Renal Cell/pathology , Carcinoma, Renal Cell/surgery , Female , Germany , Humans , Kidney/pathology , Kidney Neoplasms/epidemiology , Kidney Neoplasms/pathology , Logistic Models , Male , Multivariate Analysis , Neoplasm Invasiveness , Neoplasm Staging , Predictive Value of Tests , Retrospective Studies , Tomography, X-Ray Computed/statistics & numerical data , Unnecessary Procedures/statistics & numerical data
5.
Biotechnol Prog ; 18(3): 514-23, 2002.
Article in English | MEDLINE | ID: mdl-12052068

ABSTRACT

The bioconversion of L-phenylalanine (L-Phe) to 2-phenylethanol (PEA) by the yeast Saccharomyces cerevisiae is limited by the toxicity of the product. PEA extraction by a separate organic phase in the fermenter is the ideal in situ product recovery (ISPR) technique to enhance productivity. Oleic acid was chosen as organic phase for two-phase fed-batch cultures, although it interfered to some extent with yeast viability. There was a synergistic inhibitory impact toward S. cerevisiae in the presence of PEA, and therefore a maximal PEA concentration in the aqueous phase of only 2.1 g/L was achieved, compared to 3.8 g/L for a normal fed-batch culture. However, the overall PEA concentration in the fermenter was increased to 12.6 g/L, because the PEA concentration in the oleic phase attained a value of 24 g/L. Thus, an average volumetric PEA production rate of 0.26 g L(-1) h(-1) and a maximal volumetric PEA production rate of 0.47 g L(-1) h(-1) were achieved in the two-phase fed-batch culture. As ethanol inhibition had to be avoided, the production rates were limited by the intrinsic oxidative capacity of S. cerevisiae. In addition, the high viscosity of the two-phase system lowered the k(l)a, and therefore also the productivity. Thus, if a specific ISPR technique is planned, it consequently has to be remembered that the productivity of this bioconversion process is also quickly limited by the k(l)a of the fermenter at high cell densities.


Subject(s)
Phenylalanine/metabolism , Phenylethyl Alcohol/metabolism , Saccharomyces cerevisiae/metabolism , Fermentation
6.
BJU Int ; 89(6): 517-22, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11942955

ABSTRACT

OBJECTIVES: To further clarify the need for routine adrenalectomy during the surgical treatment of renal cell cancer, as in the absence of clinically overt metastatic disease, tumorous lesions within the adrenal gland are found in only 2-10% of patients, with most being over-treated by adrenalectomy. PATIENTS AND METHODS: The medical records of 819 patients undergoing adrenalectomy combined with nephrectomy, irrespective of the local extension of the primary tumour or the clinical stage at first diagnosis, were reviewed to determine the reliability of currently available imaging methods in predicting adrenal gland metastases. Several patient and tumour characteristics were correlated with the presence of intra-adrenal metastases, and their possible independent prognostic value was determined by a multivariate logistic regression model. RESULTS: There was metastatic spread into the adrenal gland in 27 of 819 (3.3%) patients. In only three of eight patients in whom the adrenal was identified as the only metastatic site were preoperative abdominal computed tomography scans interpreted as false-negative. On multivariate statistical analysis only the presence of distant metastases, vascular invasion within the primary tumour and multifocal growth of renal cell cancer within the tumour-bearing kidney were identified as independent predictors of the presence of intra-adrenal metastases. CONCLUSIONS: None of the patient or tumour characteristics evaluated reliably predicted the likelihood of adrenal metastases in patients with no evidence of disseminated metastatic spread. However, previously published data indicate that the frequency of metachronous metastases within the contralateral kidney (1.8-3.8%) is significantly higher than the risk of a preoperatively undetected isolated intra-adrenal metastatic lesion when currently available imaging modalities are applied. Therefore, routine adrenalectomy should not be recommended if the preoperative radiological examinations are normal.


Subject(s)
Adrenal Gland Neoplasms/secondary , Adrenalectomy/methods , Carcinoma, Renal Cell/surgery , Kidney Neoplasms/surgery , Adrenal Gland Neoplasms/surgery , Female , Humans , Logistic Models , Male , Prognosis , Regression Analysis
7.
Urologe A ; 38(5): 460-5, 1999 Sep.
Article in German | MEDLINE | ID: mdl-10501704

ABSTRACT

In approximately 4-10 % of patients presenting with renal cell cancer the transluminal propagation of a tumor thrombus into the vena cava inferior or the right atrium comes to diagnosis. Recent investigations have indicated that the presence of neoplastic extension into the venous system does not reveal independent prognostic value regarding the clinical course of the disease. Although the complete surgical removal of vena cava thrombosis in patients without simultaneously occurring regional lymph node or distant metastases has become a well established treatment modality, several questions concerning this surgical strategy still remain the subject of ongoing discussions. In the present investigation that included 92 patients with renal cell cancer and intracaval neoplastic extension it was clearly demonstrated that the use of cardiopulmonary bypass, deep hypothermia and circulatory arrest preferably during the removal of intracaval thrombosis extending into the right atrium does not result in a substantially increased treatment-related intra- or postoperative mortality. However, in contrast to a previously reported observation this treatment option did not reveal any substantial impact on the long-term survival of the patients following surgical therapy. Accordingly, the cranial extension of intracaval thrombosis was not identified as a biological variable of any prognostic importance for renal cell cancer patients.


Subject(s)
Carcinoma, Renal Cell/secondary , Extracorporeal Circulation , Kidney Neoplasms/surgery , Neoplastic Cells, Circulating , Vascular Neoplasms/secondary , Vena Cava, Inferior , Adult , Aged , Carcinoma, Renal Cell/mortality , Carcinoma, Renal Cell/surgery , Female , Humans , Hypothermia, Induced , Kidney Neoplasms/mortality , Male , Middle Aged , Prognosis , Survival Rate , Vascular Neoplasms/mortality , Vascular Neoplasms/surgery , Vena Cava, Inferior/surgery
8.
Orthopade ; 25(5): 435-40, 1996 Sep.
Article in German | MEDLINE | ID: mdl-8966036

ABSTRACT

Pseudarthroses of the spine are classified into congenital, acquired non-traumatic, posttraumatic and postoperative (iatrogenic) pseudarthroses. The various types of non-unions of the spine are described according to their clinical and radiological appearance. In line with their clinical importance, special attention with respect to the operative treatment is given to non-union of the axis of C2 and to spondylolysis. For the pseudarthrosis of the dens a posterior fusion according to Gallie-Brooks is recommended, in spondylolysis without marked slipping a "direct repair" should be considered in young patients.


Subject(s)
Pseudarthrosis/etiology , Spinal Diseases/etiology , Child , Child, Preschool , Female , Humans , Iatrogenic Disease , Infant , Infant, Newborn , Male , Odontoid Process/injuries , Postoperative Complications/etiology , Pseudarthrosis/congenital , Pseudarthrosis/diagnostic imaging , Pseudarthrosis/surgery , Radiography , Spinal Diseases/diagnostic imaging , Spinal Diseases/surgery , Spinal Fractures/therapy , Spinal Fusion , Spinal Injuries/complications , Spondylolysis/complications
9.
J Biotechnol ; 22(3): 329-51, 1992 Feb.
Article in English | MEDLINE | ID: mdl-1367988

ABSTRACT

The dynamic behaviour of the cell cycle and the physiology of Saccharomyces cerevisiae was monitored in transient experiments. Frequent flow cytometric analyses of the DNA (nuclear phase state) and the cell size enabled us to characterize the proliferation properties of yeast cells under well controlled and undisturbed cultivation conditions. Preliminarily, the correlation between flow cytometric light scattering measurements and the cell size was attested for yeasts. These flow cytometric results are compared with the physiological behaviour of the culture that was detected by high resolution on-line analyses and off-line measurements. The presented results focus on the importance of the yeast cell cycle behaviour for the dynamic growth characterization. Any kind of transients in yeast cultures induced partial synchronization. The characteristics and the time course of the yeast cell cycle were found to be strongly dependent on the physiological environment.


Subject(s)
Cell Cycle , Saccharomyces cerevisiae/cytology , Cell Cycle/genetics , DNA, Fungal/analysis , Flow Cytometry , Indicator Dilution Techniques , Kinetics , Mitochondria/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/growth & development
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