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S Sander

Publications and source records attributed to S Sander.

At least 37 records · Page 2Linked to original sources
PubMed2000

IR and UV spectra of the matrix-isolated peroxy radicals CF3OO, trans-FC(O)OO, and cis-FC(O)OO

The peroxy radicals CF3OO and FC(O)OO are prepared in high yields by vacuum flash pyrolysis of ROONO2 or ROOOR (R=CF3, FC(O)), highly diluted in inert gases, and subsequent isolation in inert-gas matrices by quenching the product mixtures at low temperatures. The IR spectrum of FC(O)OO was observed for the first time and eight fundamentals as well as several combinations were measured and assigned for both cis and trans rotamers of FC(O)OO. Discrepancies in an earlier assignment of the fundamentals of CF3OO have been eliminated and its IR spectrum is reported fully. The matrix UV spectra of both peroxy radicals (X2A"--> 2(2)A" transition) are in agreement with the gas-phase spectra; however, there are differences in the absorption cross-sections, for which possible reasons are discussed. The X2A"--> 1(2)A' transitions in the near IR region are too weak to be detected with our instrumentation.

Journal Article↗
PubMed2000

Vibrational Spectra of cis and trans Oxalyl Fluoride and Their Site-Selective IR-Induced Rotamerization in an Argon Matrix.

A cis/trans equilibrium mixture of matrix-isolated oxalyl fluoride was irradiated with a narrowband tunable IR source in the 2nu (CO) spectral region (3680-3710 cm(-1)). Rotamerization of cis into trans and vice versa was achieved (even site selective) by selective IR pumping. The experiments strongly aided a detailed IR analysis of both rotamers. For a complete vibrational analysis, low-temperature Raman measurements were also performed. With the exception of the torsional vibration of cis oxalyl fluoride, all the fundamentals of both rotamers have been observed. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Epidemiological situation and treatment of patients with thalassemia major in Germany: results of the German multicenter beta-thalassemia study.

At present, about 300 patients in Germany suffer from thalassemia major. In 1990, a multicenter study was introduced to identify all thalassemic patients in Germany as well as to establish a uniform therapy protocol, including follow-up diagnostic procedures. After 6 years of study, the data of 203 patients were analyzed. The majority originate from endemic regions around the Mediterranean Sea. The median age of the patients is 13.8 years (range 1-37.5 years). At present, about 20% of the patients are older than 21 years. Regarding transfusion therapy, a shortening of the average transfusion interval to 3 weeks in most cases occurred. Throughout the entire period, median baseline hemoglobin concentrations of 10.0 g/dl were observed. The evaluation of serum ferritin levels revealed considerable differences, depending on the patients' age. Thalassemic patients in the first decade of life generally presented with good therapeutic results; serum ferritin levels were below 1800 ng/ml in 76/102 patients (75%) upon entry into the study. In contrast, 51/98 patients (52%) older than 10 years had ferritin levels above 2500 ng/ml. More than half of all treated patients presented with siderotic complications such as cardiac disease in 20/157 (13%), liver disease in 32/157 (21%), impaired glucose metabolism in 22/157 (14%), hypogonadism in 39/66 (59%), and hypothyroidism in 38/157 (24%) who were under treatment at the time of first survey. Since the situation concerning siderosis and the lack of compliance proved to be particularly difficult with adolescent patients, further efforts should concentrate on this age-group.

Adolescent↗
PubMed2000

Trauma and melanoma formation: a true association?

BACKGROUND: Little is known about the role of mechanical trauma in the pathogenesis of malignant melanoma. In individual patients, traumatic events have been discussed as a causative factor for the induction of melanoma and diagnosis of melanoma following trauma may raise medico-legal questions. OBJECTIVES: To evaluate the relationship between traumatic single or recurrent events and melanoma characteristics. METHODS: Retrospective questionnaire in 369 melanoma patients. RESULTS: A large number of patients (337 of 369; 91.3%) denied an association between a possible traumatic event and melanoma formation. Thirty-two of 369 patients (8.7%) considered an association of trauma and melanoma formation likely. Of these 32 patients, 22 patients (13 men, nine women) reported a single event, and 10 patients (four men, six women) a persisting irritation. An irritation of a pre-existing melanocytic naevus was reported by two patients with histologically confirmed melanoma on acquired or congenital naevus. CONCLUSIONS: As most of the patients who mentioned a trauma in this study suffered from acral melanoma, or melanoma located on the extremities, a history of trauma should be expected more frequently at these body sites. A review of epidemiological, clinical and scientific research indicates that there seems to be no evidence for single or persistent traumatic events as a causative factor for melanoma formation.

Adolescent↗
PubMed2000

Clinical syndromes associated with tomacula or myelin swellings in sural nerve biopsies.

OBJECTIVES: To describe the neuropathological features of clinical syndromes associated with tomacula or focal myelin swellings in sural nerve biospies and to discuss possible common aetiopathological pathways leading to their formation in this group of neuropathies. METHODS: Fifty two patients with sural nerve biopsies reported to show tomacula or focal myelin swellings were reviewed, light and electron microscopy were performed, and tomacula were analysed on teased fibre studies. Molecular genetic studies were performed on those patients who were available for genetic testing. RESULTS: Thirty seven patients were diagnosed with hereditary neuropathy with liability to pressure palsies (HNPP), four with hereditary motor and sensory neuropathy type I (HMSN I) or Charcot-Marie-Tooth disease type 1 (CMT1), four with HMSN with myelin outfolding (CMT4B), three with IgM paraproteinemic neuropathy, three with chronic inflammatory demyelinating polyneuropathy (CIDP), and one with HMSN III (CMT3). CONCLUSIONS: Most of these syndromes were shown to be related to genetic or immunological defects of myelin components such as peripheral myelin protein 22 (PMP22), myelin protein zero (P0), or myelin associated glycoprotein (MAG). These proteins share the HNK-1 epitope which has been implicated in cell adhesion processes. Impaired myelin maintenance may therefore contribute to the formation of tomacula and subsequent demyelination.

Adult↗
PubMed2000

Nephrectomy - indications, complications and postoperative mortality in 646 consecutive patients.

OBJECTIVE: To gain information about the indications for and complications of conventional nephrectomy, also to create standards for future evaluation of nephrectomies performed by minimal invasive techniques. METHODS: We present a historical 20 years' series of 646 consecutive nephrectomies performed in the period of 1978-1997. Malignant disease led to the operation in 437 cases, of which 98 were urothelial tumors in the renal pelvis or ureter. 209 kidneys were removed due to benign conditions. The incidence of nephrectomy for benign conditions has declined from 75 in the first 5-year period to 32 in the last. RESULTS AND DISCUSSION: Postoperative complications occurred in 100 patients (15.5%). Nephrectomy for malignant disease had a significantly higher rate of complications than operations for benign conditions (p<0.001), especially hemorrhagic complications and pneumonias were more frequent. There were no differences as a result of the operative approach. Reoperation was carried out in 3.0% of the cases. Overall mortality rate (<30 days) was 3.1%.

Aged↗
PubMed2000

Prospective randomized trial of early versus late enteral iron supplementation in infants with a birth weight of less than 1301 grams.

OBJECTIVES: To examine whether early enteral iron supplementation (EI) would improve serum ferritin as a measure of nutritional iron status at 2 months of age and would prevent definite iron deficiency (ID) in infants with a birth weight of <1301 g. METHODS: Infants were randomly assigned to receive enteral iron supplementation of 2 to 6 mg/kg/day as soon as enteral feedings of >100 mL/kg/day were tolerated (EI) or at 61 days of life (late enteral iron supplementation [LI]). Nutritional iron status was assessed: 1) at birth, 2) at 61 days of life, 3) when the infants reached a weight of 1.6 times birth weight, and 4) before blood was transfused at a hematocrit of <.25. ID was defined by any one of the following criteria: ferritin, <12 microg/L; transferrin saturation, <17%; or increase of absolute reticulocyte counts by >50% one week after the onset of enteral iron supplementation. Restrictive red cell transfusion guidelines were followed and all transfusions were documented. Erythropoietin was not administered. The primary outcome variables were: 1) ferritin at 61 days and 2) the number of infants with ID. RESULTS: Ferritin at 61 days was not different between the groups. Infants in the LI group were more often iron-deficient (26/65 vs 10/68) and received more blood transfusions after day 14 of life. No adverse effects of EI were noted. CONCLUSIONS: EI is feasible and probably safe in infants with birth weight <1301 g. EI may reduce the incidence of ID and the number of late blood transfusions. ID may occur in very low birth weight infants despite early supplementation with iron and should be considered in the case of progressive anemia.preterm infant, iron supplementation, iron deficiency, blood transfusion.

Drug Administration Schedule↗
PubMed1999

[Monotherapy with antiandrogens for prostatic cancer].

Bicalutamide (Casodex) is a new antiandrogen, so far approved for the treatment of prostate cancer in combinations with a GnRH agonist. Results from large, well controlled studies show that monotherapy with bicalutamide is an interesting alternative to surgical or medical castration for patients with advanced prostate cancer. The efficacy generally appears to be similar to that of castration, but without the well known side effects of castration such as hot flushes, reduced sexual interest and functioning, and reduced physical capacity. Bicalutamide is well tolerated, but some patients will experience gynaecomastia and/or breast tenderness, and they should be informed about this before treatment is started. Monotherapy with bicalutamide is an attractive first line treatment for these patients in order to maintain optimal quality of life for as long as possible. Studies show that many patients will respond to second line treatment with castration if bicalutamide has failed.

Androgen Antagonists↗
PubMed1999

Management of rectal prolapse in children: Ekehorn's rectosacropexy.

Although surgical intervention is occasionally required for rectal prolapse (RP), there is both vagueness as to the indications for surgery and confusion as to the technique that should be used for children who need surgical treatment. Using Ekehorn's transanal suture rectosacropexy technique, 56 children with RP were treated surgically between 1987 and 1998 at our hospital. There were 36 boys and 20 girls, the average age was 4.5 years, and the duration of the recurrent prolapse prior to admission ranged from 3 to 8 months. The technique consists of simply inserting one "U"-shaped suture through the rectal ampulla and tying the strands of the suture outside at the level of the sacrococcygeal junction. In this series, follow-up periods ranged from 1 to 10 years and there were no recurrences. We believe that surgical indications for RP need to be defined more clearly and that Ekehorn's technique offers a simple and effective method for the surgical treatment of complete RP in children.

Adolescent↗
PubMed1999

Jugular phlebectasia in children: is it rare or ignored?

BACKGROUND/PURPOSE: Phlebectasia of the jugular veins is a venous anomaly that usually presents in children as a soft cystic swelling in the neck during straining. The purpose of this report is to discuss the differential diagnosis, the methods of imaging, the mode of treatment, and to demonstrate some factors that have made us believe that the condition may not be an actual rarity but rather has been ignored. METHODS: Eight cases of unilateral internal jugular phlebectasia were treated surgically (ie, excision of the dilated portion of the vein) from 1987 to 1998. The age of the patients ranged from 3 to 14 years. There were 3 girls and 5 boys. The lesions were right sided in 6, and left sided in 2 children. The patients underwent surgery after comparative ultrasonographic confirmation of the diagnosis. Furthermore, the authors prepared a simple questionnaire for evaluating the level of knowledge about this lesion among the related specialists. One hundred ten physicians were asked to describe the jugular phlebectasia and its ideal treatment. RESULTS: All of the patients were discharged from the hospital 24 hours after surgery. Follow-up periods ranged from 6 months to 6 years and no complaints were noted at the time of most recent visits. Our questionnaire results showed that 96% of 73 pediatricians, 37% of 22 otorhinolaryngologists, and 40% of 15 pediatric surgeons did not know what the jugular phlebectasia was. CONCLUSIONS: Color Doppler sonography alone is sufficient for the diagnosis of jugular phlebectasia. The authors recommend surgical excision in asymptomatic cases for cosmetic and psychological purposes. The rarity of the lesion may be caused by a lack of knowledge among the related physicians and the tendency of reporting only surgical results.

Adolescent↗
PubMed1999

S-100 protein in peripheral blood: a marker for melanoma metastases: a prospective 2-center study of 570 patients with melanoma.

BACKGROUND: S-100 protein, commonly used in the immunohistochemical diagnosis of malignant melanoma and melanoma metastases, has recently been introduced as a tumor marker in peripheral blood. OBJECTIVE: This prospective, observational, 2-center study evaluates S-100 in peripheral blood of patients with melanoma as a marker for metastasis. METHODS: With application of an immunoluminometric assay, S-100 levels in 1396 samples of 570 patients with melanoma and 53 control subjects were measured in a blinded manner. RESULTS: The cut-off level for patients with melanoma without medical history of metastases versus patients with newly occurring lymph node, visceral, and/or brain metastases was 0.114 microg/L, with a sensitivity of 94% (95% confidence interval, 86.4%-98.5%) and a specificity of 91% (95% confidence interval, 87.7%-93.6%). False-negative results included patients with unknown primary melanoma and those with amelanotic melanoma metastases. CONCLUSION: The data suggest that S-100 in the peripheral blood of patients with melanoma could serve as a marker indicating new melanoma metastases and could help to monitor the course of the disease.

Adolescent↗
PubMed1999

Activated non-neural specific T cells open the blood-brain barrier to circulating antibodies.

Previous studies have shown that activated T cells can successfully cross endothelial barriers and will accumulate in tissue which contains their specific antigen. Myelin specific T cells (e.g. myelin basic protein specific) are recognized to play an important role in the induction of experimental autoimmune demyelinating disease of the CNS and have been shown to induce blood-brain barrier breakdown effectively. In this study we injected T cells reactive to a non-neural antigen (ovalbumin) systemically into Lewis rats and caused them to accumulate in the thoracic dorsal column by a prior injection of ovalbumin. Selected rats were given systemic demyelinating antibody, antimyelin oligodendrocyte antibody (anti-MOG antibody), to provide evidence of permeability changes to the blood-brain barrier. These animals were compared with control rats given systemic anti-P0 monoclonal antibody and to other rats given a direct micro-injection (3 microliters) of anti-MOG antibody into the thoracic dorsal column. All animals were monitored by serial neurophysiological studies and by histological examination. Direct anti-MOG antibody injection produced a focal block in conduction at the injection site and a large circumscribed area of primary demyelination with axonal preservation within the dorsal column. An even more profound conduction block and more extensive plaque-like region of demyelination were seen in animals given antigen, activated T cells and systemic antibody. However, animals given antigen and T cells without relevant antibody did not show conduction impairment or demyelination, except when very large numbers of T cells were given; such rats developed severe irreversible axonal damage. This study demonstrates the blood-brain barrier is disrupted by activated T cells of non-neural specificity and allows large plaque-like regions of demyelination to form in the presence of circulating antimyelin antibody. The relevance of this finding to multiple sclerosis is discussed.

Animals↗
PubMed1998

Charcot-Marie-Tooth disease: histopathological features of the peripheral myelin protein (PMP22) duplication (CMT1A) and connexin32 mutations (CMTX1).

The two most common subtypes of Charcot-Marie-Tooth (CMT) disease are CMT1A and CMTX1. To determine whether these different genetic entities display different morphological phenotypes we compared sural nerve biopsies of CMT1A patients due to PMP22 duplication with biopsies of CMTX1 patients with proven Connexin32 mutations. In CMT1A nerve biopsies we found a severe reduction in myelinated fiber density, hypermyelination as well as demyelination, and a high percentage of onion bulb formations. CMTX1 nerve biopsies showed significant differences: a higher myelinated fiber density, thinner myelin sheaths, more cluster formations, and only few onion bulb formations. Teased fibers studies in CMT1A patients showed features of demyelination and/or remyelination in almost all fibers. In contrast, teased fibers of CMTX1 patients were uniformly thinly myelinated with 5-10% active axonal degeneration and 15% segmental demyelination. Median nerve motor conduction velocities were significantly faster in CMTX1 patients (31.6+/-5.5 m/s) than in CMT1A patients (18.2+/-6.9 m/s). The possible roles of PMP22 and Connexin32 in the pathogenesis of CMT are discussed.

Adolescent↗
PubMed1998

Are in-vitro platelet function tests useful in predicting blood loss following open heart surgery?

BACKGROUND: We investigated the suitability of two commercially available in-vitro bleeding tests (IVBT), the PFA-100 and the Hepcon HMS, to predict blood loss following operations with extracorporeal circulation (ECC) and compared them with conventional coagulation studies. METHODS: In 40 patients subjected to elective open heart surgery with ECC a blood sample was taken before and after ECC to measure platelet count, prothrombin time, aPTT, D-dimers, fibrinogen, and PFA-100 and Hepcon HMS data. The postoperative blood loss was recorded hourly until removal of drains. RESULTS: A significant correlation was found between total blood loss (250-1750 ml) and the preoperative PFA-100 (r = 0.41, p = 0.022), the preoperative platelet count (r = -0.42, p = 0.007), the preoperative D-dimer concentration in the plasma (r = 0.41, p = 0.01), and duration of ECC (r = 0.35, p = 0.044). There was no significant correlation between blood loss and the Hepcon HMS system. CONCLUSIONS: Although a significant correlation was found between blood loss and the PFA-100 IVBT, the practical value of these tests in the clinical situation is limited due to a great variability in individual results.

Aged↗