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Biomedical subjects

R Sauer

Publications and source records attributed to R Sauer.

324 records · Page 18Linked to original sources
PubMed1970

The N-terminal amino acid sequence of two avian leukosis group specific antigens.

Two group-specific antigenic proteins from an avian leukosis virus have been compared by amino acid analysis, tryptic peptide fingerprinting, and N-terminal sequence determination, and found to be dissimilar. There was microheterogeneity in the structure of the protein gs-b at residues 6; threonine and glutamic acid were found.

Amino Acid Sequence↗
PubMedDate not supplied

Perioperative radiotherapy and concurrent radiochemotherapy in rectal cancer.

Combined modality treatment is the recommended standard adjuvant therapy for patients with locally advanced rectal cancer in the United States and Germany. During the last decade substantial progress has been made in treatment modalities, and surgical management currently includes a broad spectrum of operative procedures ranging from radical operations to innovative sphincter-preserving techniques. Specialized groups have reported excellent local control rates with total mesorectal excision (TME) alone. New and improved radiation techniques (conformal and intraoperative radiotherapy) and innovative schedules (protracted intravenous and chronomodulated infusion) and combinations (oxaliplatin and irinotecan) of chemotherapy may have the potential to further increase the therapeutic benefit of adjuvant treatment. Moreover, the basic issue of timing (pre- or postoperative) within a multimodal regimen is currently being addressed in prospective trials. Evidently there is a need to question the current monolithic approaches, which were established by studies conducted more than a decade ago. It is also under discussion whether to apply the same schedule of postoperative radiochemotherapy to all patients with stage II/III rectal cancer, or to give preoperative intensive short-course radiation according to the Swedish concept for all patients with resectable rectal cancer irrespective of tumor stage and treatment goal (e.g., sphincter preservation). This review discusses different irradiation settings in more recent and ongoing studies of perioperative radiotherapy for rectal cancer, and focuses on the issue of which patient should receive radiotherapy (if at all), and if so, how and when.

Chemotherapy, Adjuvant↗
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Bladder preservation in muscle-invasive bladder cancer by conservative surgery and radiochemotherapy.

Organ preservation has been investigated in muscle-invasive bladder cancer over the past decades as an alternative to standard radical cystectomy. The results of large prospective protocols and population-based studies suggest that an organ-preserving approach is possible without deferring the survival probability. Organ preservation requires a trimodal schedule, including transurethral surgery (transurethral resection of bladder tumor (TURBT)), radiation, and chemotherapy. A complete TURBT is the most important single prognostic factor, and should be attempted. Radiotherapy, in conjunction with concurrent platinum-based chemotherapy, can control the vast majority of urothelial bladder tumors. The histologically-proven complete remission rates of macroscopic tumors (unresectable by TURBT) lie in the range of about 70%. After radiochemotherapy, a histological response evaluation with repeated TURBT is recommended. Patients with residual tumor require salvage cystectomy. In cases of complete remission, patients can maintain their bladders but they should be closely followed over years. The risk of severe late-radiation sequelae is low, in the range of less than 5%. About 75% of long-term survivors maintain a normally functioning bladder.

Humans↗
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[Risk factors for the determination of transfusion requirements during implantation of hip endoprostheses].

AIM: We have carried out an observational study to determine the pre-operative risk factors for transfusion in patients undergoing implantation of a hip prosthesis. METHOD: 47 patients were recruited to the study. The following parameters were recorded: peri-operative transfusions, infusions, blood and secretion losses, re-transfusions and other operative variables. In addition, patient-specific data (age, body mass index, co-existing conditions, haemoglobin) were determined. The data were grouped by transfusions and re-transfusions and submitted to statistical analysis. RESULTS: The transfusion incidence in knee endoprosthesis implantation procedures was low at 25.5 %. Age above 74 years, ASA 3 and 4 were identified as significant risk factors for transfusion. If the significant risk groups identified in this study are left aside, a transfusion incidence of 5.6 % is found. CONCLUSION: For the implantation of an artificial hip joint, we recommend autologous blood donation only for patients with ASA 3. For other patients it is recommended that homologous banked blood (2 units of cross-matched concentrated red cells) be held in readiness.

Aged↗
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[Radiotherapy in Ewing sarcoma: current results of the German Society of Pediatric Oncology studies CESS 81 and CESS 86].

In CESS 81 the rate of local recurrences was high particularly in patients with radiation for local control. To improve the safety of local control, in the follow-up study CESS 86 chemotherapy for high risk patients was intensified. The combination of surgery with postoperative radiation was favoured when possible, local control was brought forward from week 18 to week 9, the doses of postoperative radiotherapy was increased from 36 to 46 Gy, and a radiation planning center was established for centralized planning of radiotherapy on the basis of tumor extension at diagnosis. In addition patients with radiation were randomized for conventional fractionation or a scheme of accelerated split course hyperfractionation with simultaneous chemotherapy. Preliminary results of 76 CESS 86 patients (incl. pilot phase), show a lowered rate of local recurrences compared to CESS 81: 6% local recurrences and 15% local recurrences in patients with radiation. With selection of patients with small and chemoresponsive tumors for radiotherapy no longer a disadvantage was seen for patients with radiotherapy concerning the safety of local control.

Antineoplastic Combined Chemotherapy Protocols↗
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[The Cooperative Ewing Sarcoma Study CESS 81 of the German Pediatric Oncology Society--analysis after 4 years].

In 1981 the cooperative Ewing's sarcoma study CESS 81 was initiated with initial 18-weeks-chemotherapy consisting of vincristine, actinomycin D, cyclophosphamide and adriamycin (VACA) followed by local therapy consisting of either radical surgery with complete resection of the involved bone or incomplete resection followed by radiation with 36 gy or radiotherapy only. Patients with radiation only for local therapy and extremity tumor sites are randomised for 46 gy vs 60 gy tumor dose. Following local therapy chemotherapy is continued for an additional 18 weeks. The actuarial results of 83 consecutive patients entered from 51 participating institutions from January 1, 1981, until November 15, 1984 are presented. 68/83 patients were off therapy and under observation for longer than one year following diagnosis. The longest follow-up was 41 months. On November 15, 1984, 39/68 (57%) patients were disease free. According to the site of the primary tumor patients with distal extremity lesions had a more favourable prognosis as compared to proximal extremity and central lesions. According to local therapy patients with radical surgery had a better prognosis as compared to those with resection followed by radiation and those with radiation only for local control. Analysis according to tumor volume revealed the strong interaction between tumor site, local therapy and tumor volume. According to life-table-analysis the disease free survival for patients with a tumor volume less than 100 ml was 75% after 41 months compared to 10% for patients with a tumor volume greater than or equal to 100 ml. The consequences of this analysis for a stratified treatment regimen for patients with primary Ewing's sarcoma of bone are discussed.

Adolescent↗
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[Radiation therapy in the prevention of periarticular, heterotopic ossification following implantation of a total hip endoprosthesis].

From June 1988 to January 1991 the efficacy of a low-dose (5 x 2 Gy) versus a high-dose (10 x 2 Gy, resp. 5 x 3,5 Gy) prophylactic postoperative radiotherapy was assessed in a prospective randomized trial. 60 patients at the highest risk for formation of heterotopic ossification (HO) were included in this study, i.e. patients that presented already HO in the ipsi- or contralateral hip at the time of surgery. After both irradiation regimen the incidence and severity of HO was significantly less than without prophylaxis; there was no significant difference (regarding the severity of HO, the hip score (16) and the hip mobility) between the two regimen.

Adult↗
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MDR1 single nucleotide polymorphism C3435T in normal colorectal tissue and colorectal carcinomas detected by MALDI-TOF mass spectrometry.

Single nucleotide polymorphisms (SNPs) may contribute to the malignant process and may show clinicopathological importance as prognostic markers. The multidrug resistance gene MDR1 encodes a membrane transporter which confers cytostatic drug resistance in tumors and protects normal tissues from xenobiotics. We analyzed the C3435T SNP in the MDR1 gene which is associated with altered cellular drug uptake in matched tumor and normal tissues of 45 patients suffering from colorectal carcinoma. We have developed a highly sensitive matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) method to survey the C3435T polymorphism in PCR-amplified fragments of the MDR1 gene. Thirteen patients were homozygous for C/C (29%), 15 were heterozygous (33%) and 17 were homozygous for T/T (38%). None of the tumor samples showed an altered SNP compared to their matched normal tissue samples. As analyzed by the Kruskall-Wallis test, none of the clinicopathological parameters was significantly associated with homo- or heterozygosity. The combination of PCR, allele-specific primer extension reactions and MALDI-TOF-MS offers a promising alternative method for genotyping the MDR1 gene especially for heterozygous situations. The inherent advantages of MALDI-TOF-MS based genotyping include its high molecular resolution, high signal-to-noise-ratios and reproducibility, combined with an excellent sensitivity. As none of the tumor samples showed an altered state compared to their matched normal tissue samples, the genotypic frequency of this polymorphism seems not to be altered during colorectal tumorigenesis.

Adult↗
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Radiochemotherapy after transurethral resection is an effective treatment method in T1G3 bladder cancer.

AIM: Conservative therapy using deep transurethral resection (TUR) followed by radiochemotherapy is a novel treatment strategy in stage TI grade 3 (TIG3) transitional cell carcinoma (TCC) of the bladder. The aim of this study was to present our long-term results of radiochemotherapy in T1G3 TCC patients. MATERIALS AND METHODS: A total of 64 patients with TIG3 TCC of the bladder underwent a TUR and a subsequent radiochemotherapy protocol at our institution. Following TUR, a median dose of 55.8 (range; 45-69.4) Gy radiation therapy was applied to the bladder, and simultaneous chemotherapy was initiated using cisplatin, carboplatin and/or 5-fluorouracil. After completion of the protocol, response was evaluated by repeat TUR, and check cystoscopies were performed at regular intervals. Median patient age was 66 (range; 30-82) years and median follow-up was 43.2 (range; 6-127) months. RESULTS: Complete response was achieved in 55 (90.2%) patients. Of the complete responders, 7 patients experienced a superficial (Ta, T1) recurrence and 8 patients had progression. In 8 patients with refractory superficial and invasive relapses, a salvage cystectomy was mandated. The overall progression rate was 14%. The overall and disease-free survival rates were 76% and 93%, respectively at 5 years. During followup, 4 patients suffered from reduced bladder capacity, and 2 patients underwent cystectomy due to shrinking bladder. CONCLUSION: Combined multimodality therapy is a safe and curative treatment option for patients with T1G3 TCC of the bladder in the hands of dedicated multimodality teams. Therefore, it is reasonable to justify radiochemotherapy combined with TUR in the first-line treatment of T1G3 tumors.

Adult↗
PubMedDate not supplied

Grading system for breast cancer.

As recurrence rates in breast cancer depend significantly on degree of malignancy (6-9) and mitotic rates as part of the grading system are difficult to assess in exact manner, we widened the grading system by evaluation of the proliferative compartment to get more information about proliferation activity as an important factor for tumor-progression (15, 16). This additional analysis can be used as a control factor for the correctness of the evaluation of mitotic activity. We practice this procedure at present as a "working formulation". New antibodies are in preparation which allow to exclude the highly variable G1-Phase. Further precision and control of degree of malignancy can be achieved by photometric analysis of S-Phase, 5c exceeding rate and state of ploidy according to Auer scheme.

Adult↗