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M Langer

Publications and source records attributed to M Langer.

At least 55 records · Page 3Linked to original sources
PubMed2002

[Comparison of MR-sequence in the diagnosis of anal fistula--the clinical value of 3D flash].

To elevate the clinical value of 3D-FLASH in the diagnosis of anal fistula and compare it with convertioned MR sequence, MR sequences, consisting of spin echo T1WI, turbo invertion recovery magnitude (TIRM), fast low-angle shot image (FLASH), mon-enhancement and enhancement substraction and coronary reconstructing, was conducted in 15 cases suspected of anal fistula. Comparison was made among the three sequences in display rate of internal fistula, external fistula, the branch of fistule connulas. Our results showed that 1 patient had perianal abscess. 24 different anal fistulas were identified in 14 patients, and 10 of them was complicated with perianal abscess and 8 of them with complex multi-branch fistula. The display rate of 3D-FLASH sequence was much higher than those of T1WI and TIRM in all cases. It is concluded that 3D-FLASH sequence is an senstive and time-efficient technique for the diagnosis of anal fistula.

Abscess↗
PubMed2002

[Relevance of magnetic resonance imaging for the staging and follow up of lymph node pathologies in adults with primary malignant lymphomas].

Lymph node histology and staging with cross sectional imaging remains basis for the treatment planning in primary malignant lymphoma. Contrast enhanced computed tomography is considered to be gold standard. However, MRI is equally able to provide staging and follow up in the same quality as helical CT, as several studies and clinical experience show. MRI is considered as the superior imaging modality for extranodal lymphoma. Advantages of MRI are that it works without ionizing radiation and contrast media;however, MRI is more expensive and time consuming. However, both imaging modalities are limited by the fact that the differentiation of affected and non affected lymph nodes is based on size only. Also the results of recent clinical studies with USPIOs (SINEREM((R):)) for intravenous MR lymphography in primary malignant lymphoma do not look promising. Despite these disadvantages of MRI, for young patients with malignant lymphoma radiation protection should be taken into account because of frequent imaging in staging and follow up.

Adult↗
PubMed2002

Achilles tendon healing: long-term biomechanical effects of postoperative mobilization and immobilization in a new mouse model.

The aim of the study was to investigate the long-term effects of postoperative immobilization as opposed to mobilization on the biomechanical attributes of healing Achilles tendons in a new experimental mouse model. In 114 Balb-C-mice the left Achilles tendon was transected and sutured by the Kirchmayr-Kessler technique. The tendons healed either under postoperative immobilization effected by fixing the upper ankle joint in equinus position or under mobilization through a limited range of movement. The contralateral Achilles tendons served as internal control. All tendons were tested biomechanically at short intervals up to the 112th postoperative day in terms of load to failure [N], tendon deflection [mm] and tendon stiffness [N/mm], and were evaluated histologically after 8 and 112 days. Postoperative mobilization resulted in a continuous and significantly more rapid restoration of load to failure in comparison to the immobilization group. Tendon deflection was decreased by postoperative mobilization, whereas under immobilization it paradoxically increased still further in the later course. After 112 days the tendons of the mobilization group had regained their original tendon stiffness, whereas the tendons after immobilization reached only about half the values seen in the control tendons. Histologically, postoperative mobilization led to increased immigration of inflammatory cells in the early phase. In the late phase, as compared to immobilization, tendon structure was more mature, with fibre bundles arranged in parallel and interposed tendocytes. Tensile loading of the healing tendon by postoperative mobilization leads to fundamental changes in the biological process of tendon healing resulting in accelerated restoration of load to failure and reduced tendon deflection.

Achilles Tendon↗
PubMed2002

[Image quality of paper prints compared to film copies in CT investigations].

PURPOSE: Evaluation of image quality of paper prints in routine CT investigations. METHOD: The image quality of paper prints from 104 CT scans of daily routine investigations was analysed by three observer three observers according to a five-point ranking scale for contrast, grey level, spatial resolution, and subjective confidence in correct evaluation. Each study was rated "acceptable" or "not acceptable for documentation". RESULTS: In 312 ratings the mean grade for contrast was 2.7, for grey levels 3.2, and for spatial resolution 3.3. Grades ranged from 1 = very good to 5 = insufficient. Subjective confidence in correct evaluation was rated as "certain" in 77.4 %, "likely" in 18.4 % and "impossible to evaluate" in 4.2 % of cases. 93.7 % of printed CT images were rated "acceptable for documentation". CONCLUSION: Image quality of paper prints does not reach the quality of laser films concerning its contrast, grey levels, and spatial resolution. Nevertheless, paper prints are acceptable for documentation of findings in most CT investigations. A high confidence in correct evaluation was found. Limitations are found in documentation of small coin lesions of the lung and ischemic lesions of the neurocranium.

Humans↗
PubMed2002

[How reliable is the posterior interosseous artery island flap? A review of 88 patients].

The distally-based, reverse posterior interosseous flap can be used to reconstruct soft-tissue defects in the region of the hand, provided there is an intact anastomotic network of the posterior and anterior interosseous system at the wrist. Between 1986 and 2000, 88 flap procedures were planned. Anatomical variations were recorded in 21 patients (24 %), in five of which the flap could not be harvested. In the remaining 16 patients, flap dissection was more difficult due to anatomical variations. There was a complication rate of 23 %, including haematoma, congestion, infection or technical errors, which resulted in flap necrosis of variable degrees in 11 patients (13 %). In case of haematoma, flap loss could be reduced by early revision surgery. There was no statistical correlation between anatomical variations and complications or flap loss. Secondary flap corrections, including defatting and remodelling, were commonly performed in due course. Knowing the limitations of the posterior interosseous flap, fasciocutaneous flaps are considered ideal to reconstruct soft-tissue defects or contractures of the thumb web and the dorsal hand because of good tissue matching. Fascial flaps are a good option for palmar defects or to wrap around neurolyzed nerves.

Adolescent↗
PubMed2001

Respiratory syncytial virus infection of the lower respiratory tract: radiological findings in 108 children.

For years the typical appearance of respiratory syncytial virus (RSV)-induced infection of the lower respiratory tract has been discussed. All available studies have led to different results. The aim of this study was to control these results, with 108 children. The age range was 1 day to 10 years (median 7 months). Within 72 h of admission, all children developed an RSV infection of the lower respiratory tract. Chest X-rays (pa-view) of 55 children under, and 53 children over, the age of 6 months (10/53>24 months) were evaluated. The diagnosis of RSV and the chest X-ray were mostly done on the same day. The major radiological findings of the two age-groups were compared by Wilcoxon's unpaired rank sum test. Major radiological findings were: normal chest X-ray (30%), central pneumonia (32%) or peribronchitis (26%). There was no statistical significance between the age-groups. Other findings were emphysema (11%), pleural effusion (6%), lobar- or broncho-pneumonia (each 6%), atelectasis (5%) or pneumothorax in one case. Therefore, the most common radiological findings in RSV-induced infection of the lower respiratory tract, supported by our results (RSV infection without bacterial superinfection) are central pneumonia, peribronchitis or normal chest X-ray. Thus an age-group separation into under or over 6 months is no longer necessary.

Bronchitis↗
PubMed2001

Novel peptide conjugates for tumor-specific chemotherapy.

One of the major problems in cancer chemotherapy are the severe side effects that limit the dose of the anticancer drugs because of their unselectivity for tumor versus normal cells. In the present work, we show that coupling of anthracyclines to peptides is a promising approach to obtain selectivity. The peptide-drug conjugate was designed to bind to specific receptors expressed on the tumor cells with subsequent internalization of the ligand-receptor complex. Neuropeptide Y (NPY), a 36-amino acid peptide of the pancreatic polypeptide family, was chosen as model peptide because NPY receptors are overexpressed in a number of neuroblastoma tumors and the thereof derived cell lines. Daunorubicin and doxorubicin, two widely used antineoplastic agents in tumor therapy, were covalently linked to NPY via two spacers that differ in stability: an acid-sensitive hydrazone bond at the 13-keto position of daunorubicin and a stable amide bond at the 3'-amino position of daunorubicin and doxorubicin. Receptor binding of these three conjugates ([C(15)]-NPY-Dauno-HYD, [C(15)]-NPY-Dauno-MBS, and [C(15)]-NPY-Doxo-MBS) was determined at the human neuroblastoma cell line SK-N-MC, which selectively expresses the NPY Y(1) receptor subtype, and cytotoxic activity was evaluated using a XTT-based colorimetric cellular cytotoxicity assay. The different conjugates were able to bind to the receptor with affinities ranging from 25 to 51 nM, but only the compound containing the acid-sensitive bond ([C(15)]-NPY-Dauno-HYD) showed cytotoxic activity comparable to the free daunorubicin. This cytotoxicity is Y(1) receptor-mediated as shown in blocking studies with BIBP 3226, because tumor cells that do not express NPY receptors were sensitive to free daunorubicin, but not to the peptide-drug conjugate. The intracellular distribution was investigated by confocal laser scanning microscopy. We found evidence that the active conjugate [C(15)]-NPY-Dauno-HYD releases daunorubicin, which is localized close to the nucleus, whereas the inactive conjugate [C(15)]-NPY-Dauno-MBS is distributed distantly from the nucleus and does not seem to release the drug within the cell.

Antibiotics, Antineoplastic↗
PubMed2001

Investigation of charge variants of rViscumin by two-dimensional gel electrophoresis and mass spectrometry.

A method for the analysis of the rViscumin heterodimer (recombinant mistletoe lectin) based on two-dimensional (2-D) polyacrylamide gel electrophoresis and mass spectrometry was developed and used for quality control concerning purity and homogeneity of the recombinant protein processed under Good Manufacturing Practice (GMP) conditions. A series of spots with different pI-values in the pH-gradient of both rViscumin A- and B-chain were observed independently from the experimental conditions like urea concentration, heat treatment or the use of cysteine alkylating agents. Comparative studies of the major spots using matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS), liquid chromatography-electrospray ionization (LC-ESI)-MS and LC-ESI-tandem MS (MS/MS) after tryptic in-gel digestion resulted in a sequence coverage of 92% for the A-chain and 95% for the B-chain. No molecular differences like common chemical or post-translational modifications or nonenzymatic deamidation were found to cause the different charge values of the separated spots. Therefore, these protein spots were extracted from the 2-D gel and separated again by 2-D gel electrophoresis (termed Re-2-DE). Each of the single spots tested in the Re-2-DE experiment split up in the same heterogeneous pattern concerning the pI-values. We suggest that the observed charge variants of rViscumin are the result of conformational protein variants, existing in an equilibrium during sample preparation and/or isoelectric focusing and are not caused from microheterogeneity in the primary structure of rViscumin.

Amino Acid Sequence↗
PubMed2001

Extent and time course of morphological changes of bone marrow induced by granulocyte-colony stimulating factor as assessed by magnetic resonance imaging of healthy blood stem cell donors.

The aim of this study was to assess the time course and extent of signal alterations of red bone marrow after short-term stimulation by recombinant human granulocyte-colony stimulating factor (rHuG-CSF) in healthy peripheral blood stem cell donors using magnetic resonance imaging (MRI) at low-field strength. Twelve healthy blood stem cell donors without evidence of bone marrow disorders were prospectively investigated and underwent four MRI studies of their lumbar spine. Sagittal T1- and T2-weighted spin-echo sequences and a gradient-echo (GE) sequence with an echo time for out-of-phase imaging were performed prior to rHuG-CSF application (baseline MRI), on the day of first stem cell harvest (after 70 microg/kg body weight rHuG-CSF, second MRI) followed by two studies 9-18 days (median 14.5 days, third MRI) and 26-48 days (median 39.5 days, fourth MRI) after discontinuation of rHuG-CSF application. Baseline MRI showed normal marrow signal in all patients. The second MRI revealed a decrease of quantified bone marrow signal relative to nucleus pulposus in T1- and T2-weighted images and an increase of relative signal in out-of-phase GE sequences. The greatest changes of relative marrow signal were observed at the third MRI. Compared to baseline MRI, relative marrow signal was diminished by 12% in T1-weighted images and increased by 59% in GE sequences, consistent with a rise in marrow cellularity simulating diffuse marrow disease. At the fourth MRI quantified relative marrow signal returned to baseline levels in all sequences. In healthy individuals rHuG-CSF application leads to significant signal changes of bone marrow in lumbar vertebra that are maximal about 2 weeks after discontinuation of rHuG-CSF application. In patients with underlying marrow disorders who receive hematopoietic growth factors during treatment, these changes should not be confused with disease progression.

Adult↗
PubMed2001

Breathhold unenhanced and gadolinium-enhanced magnetic resonance tomography and magnetic resonance cholangiography in hilar cholangiocarcinoma.

We assessed the imaging characteristics of hilar cholangiocarcinoma in magnetic resonance imaging (MRI) and magnetic resonance cholangiography (MRC). Breathhold MRI (T2-weighted turbo spin echo sequences, unenhanced T1-weighted gradient echo sequences, and gadolinium-enhanced fat-suppressed gradient echo sequences) and breathhold MRC (fat-suppressed two-dimensional projection images) performed in 12 patients with histologically confirmed hilar cholangiocarcinoma were retrospectively reviewed for morphological tumor characteristics and contrast enhancement patterns. MRC demonstrated a significant bile duct stenosis with intrahepatic bile duct dilatation in all cases except in one patient who received an endoprothesis prior to imaging. Hilar cholangiocarcinoma was diagnosed by MRC only in one patient and MRI and MRC in 11. Mass lesions were seen in nine patients and circumferential tumor growth in three, including the patient diagnosed by MRC only. The tumor appeared hypointense relative to liver parenchyma in 10 of 11 patients in unenhanced T1-weighted images. T2-weighted sequences showed isointense or only slightly hyperintense signal in 5 of 11 patients, 3 of whom demonstrated desmoplastic reactions by histology. The other 6 patients revealed strongly hyperintense signal intensities. Contrast enhancement was increased compared to liver in 5 of 11 patients and decreased in 6 of 11 patients. MRI with MRC seem to be a sensitive tools in the detection of hilar cholangiocarcinomas. The variable imaging characteristics are most probably related to the inhomogeneous histological appearance of this tumor entity.

Aged↗
PubMed2001

Perinatal mortality and morbidity. Comparison between maternal transport, neonatal transport and inpatient antenatal treatment.

The purpose was to assess differences in neonatal morbidity and mortality between maternally transferred, neonatally transferred and inborn neonates. We evaluated a continuous series of all antenatal transported infants (ATI, n=247) and postnatal transported infants (PTI, n=34) to the NICU and all preterm inborns (NTI, n=120) delivered at the University Hospital of Vienna. Data collected included sociodemographic, obstetrical and neonatal data. Mild neonatal morbidity was defined as RDS, BPD, ROP, PDA, NEC or IVH I-II, whereas severe neonatal morbidity was defined as the presence of PVL or IVH III-IV. Data were analyzed statistically using the Spearman correlation Coefficient, the Kruskal-Wallis test, and a multivariate model. There was a substantial gain in gestational age from transfer to delivery in the ATI group and from admission to delivery in the NTI group (2.1 and 5.6 weeks, respectively). The neonatal survival rate was 88.7% in the ATI and 97.5% in the NTI group. No neonate died in the PTI group; there was a significantly higher percentage of severe neonatal morbidity than in the ATI group (11.8% vs. 4.9%). We could not observe a significant difference with respect to the risk of death among the three study groups. There was a strong trend towards higher probability of severe neonatal morbidity in the NTI group. The risk of severe neonatal morbidity is much higher in the PTI-group (rel. risk 0.19, 0.06). Antenatal transfer guaranteed a significantly better neonatal outcome concerning severe neonatal morbidity than postnatal transport, and compared favorably with inborn admissions, even given the higher gestational age and birth weight in the NTI-group.

Adult↗
PubMed2001

Y-receptor affinity modulation by the design of pancreatic polypeptide/neuropeptide Y chimera led to Y(5)-receptor ligands with picomolar affinity.

Neuropeptide Y (NPY) and pancreatic polypeptide (PP) bind to the Y-receptors with very different affinities: NPY has high affinity for the receptors Y(1), Y(2) and Y(5), while PP binds only to Y(4)-receptor with picomolar affinity. By exchanging of specific amino acid positions between the two peptides, we developed 38 full-length PP/NPY chimeras with binding properties that are completely different from those of the two native ligands. Pig NPY (pNPY) analogs containing the segment 19-23 from human PP (hPP) bound to the Y-receptors with much lower affinity than NPY itself. The affinity of the hPP analog containing the pNPY segments 1-7 and 19-23 was comparable to that of pNPY at the Y(1)- and Y(5)-receptor subtypes, and to that of hPP at the Y(4)-receptor. Furthermore, the presence of the segments 1-7 from chicken PP (cPP) and 19-23 from pNPY within the hPP sequence led to a ligand with IC(50) of 40 pM at the Y(5)-receptor. This is the most potent Y(5)-receptor ligand known so far, with 15-fold higher affinity than NPY.

Amino Acid Sequence↗
PubMed2001

Comparative detectability of bone metastases and impact on therapy of magnetic resonance imaging and bone scintigraphy in patients with breast cancer.

OBJECTIVE: to evaluate the comparative impact of magnetic resonance imaging and bone scintigraphy in bone metastases of breast cancer. METHODS AND PATIENTS: in 81 patients with histologically proven breast cancer magnetic resonance imaging of the axial skeleton and whole-body bone scintigraphy had been performed. Images were retrospectively reviewed and compared for detection of metastases, extent of metastatic disease and therapeutic implications according to the patients' records. RESULTS: about 54/81 (67%) patients revealed bone metastases. In 7/54 (13%) patients with bone metastases, scintigraphy was false negative. In one patient a solitary sternal metastases was seen. In 26/53 [49%] patients with spinal metastases, magnetic resonance imaging showed more extensive disease. Local radiotherapy or surgery was indicated in ten patients with metastases not evident in bone scintigraphy, in 20 patients with positive results by both imaging modalities and in six patients with metastases of pelvis imaged by bone scintigraphy only. CONCLUSION: magnetic resonance imaging of the axial skeleton and pelvis appears superior for staging as only one patient had metastases merely outside the axial skeleton and local therapy was indicated even in spinal regions negative in bone scintigraphy.

Bone Neoplasms↗
PubMed2001

Normalization of pregnancy outcome in pregestational diabetes through functional insulin treatment and modular out-patient education adapted for pregnancy.

AIM: To investigate whether modular out-patient group education for flexible, Functional Insulin Treatment (FIT) adapted for pregnancy can eliminate diabetes-associated neonatal complications in pregestational diabetes. RESEARCH DESIGN AND METHODS: Outcome analysis of the modular out-patient group education and FIT based on separate insulin dosages for fasting, eating or correcting hyperglycaemia in 76 consecutive pregnancies (in 20 cases first after conception) of 59 patients with pregestational diabetes (Type 1 diabetes, n = 54). CONTROLS: (a) diabetic pregnancies: historical controls; (b) non-diabetic pregnancies: retrospective case-controlled study; (c) population-based data of all Austrian newborns registered within the respective time period. RESULTS: HbA1c of 113 +/- 18% of mean value (= 100%) of non-diabetic, non-pregnant population (103 +/- 14% during the last pregnancy trimester), and self-monitored blood glucose of 5.6 +/- 0.7 mmol/l (5.3 +/- 0.7 mmol/l during the last trimester) was achieved throughout all FIT pregnancies. Severe hypoglycaemia occurred in 14 pregnancies. The gestational age at delivery was 39.2 +/- 1.5 weeks (four cases (5.4%) < 37 weeks) with a birth weight of 3305 +/- 496 g. Four newborns (5.3%) were above the 90th, and nine (11.8%) below the 10th percentile for weight of reference population-based data. Hypoglycaemia was recorded in six newborns (8%). Malformations were found in two infants whose mothers booked for diabetes FIT education only after conception. The caesarean delivery rate was 25%. In comparison with historical diabetic pregnancy controls we demonstrated a reduction in major complications, and compared with non-diabetic women, a lowering of diabetes-related neonatal complication rates to general population levels. CONCLUSIONS: Structured, comprehensive, modular out-patient group education promoting self-choice of insulin dose for flexible, normal eating prior to conception normalizes pregnancy outcome in diabetes.

Adult↗
PubMed2001

Experience in upper eyelid reconstruction with the Cutler-Beard technique.

Reconstruction of full-thickness upper eyelid defects has to supply a movable lid with perfect corneal protection, good aesthetic quality, and acceptable sequelae at the donor site. The Cutler-Beard procedure, a full-thickness cutaneoconjunctival inferior eyelid advancement flap, is a reliable method for reconstruction of total or partial upper eyelid defects. Especially in older individuals, the skin of the donor site is loose and provides sufficient tissue to stretch. Color and texture of the donor matches the recipient site perfectly. Destabilization or ectropion of the donor site, the lower lid, and retraction or entropion of the recipient site, the upper lid, are the main complications. Therefore, a modification of the classic technique should be considered by implantation of an enforcing inlay in the reconstructed lid (eye bank sclera, fascia lata, ear cartilage), especially in reconstruction of extended defects of the upper lid.

Aged↗