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H Feist

Publications and source records attributed to H Feist.

At least 19 recordsLinked to original sources
PubMed2001

Synthesis of derivatives of C-nucleoside analogues using 'push-pull' functionalized monosaccharides.

7-Deoxy-1,2:3,4-di-O-isopropylidene-alpha-D-galacto-heptopyranos-6-ulose (1) reacted with carbon disulphide and methyl iodide in the presence of a base to furnish 7,8-dideoxy-1,2:3,4-di-O-isopropylidene-8,8-[bis(methylthio)]-alpha-D-galacto-oct-7-enopyranos-6-ulose (2). This 'push-pull' activated unsaturated monosaccharide underwent a ring closure reaction with hydrazine hydrate to give the 'inversed' C-nucleoside analogue 3. Compound 1 and malononitrile yielded the 7-cyano-6,7-dideoxy-1,2:3,4-di-O-isopropylidene-6-methyl-alpha-D-galacto-oct-6-enopyranurononitrile (4). Treatment of 4 with carbon disulphide and methyl iodide in the presence of a base afforded the sugar 'push-pull' butadiene 5 which was transformed into the pyridine nucleoside analogue 6.

Antineoplastic Agents↗
PubMed2001

Surgery as primary treatment in patients with liver metastases from carcinoid tumors: a retrospective, unicentric study over 13 years.

BACKGROUND: The heterogeneous nature of carcinoid tumors makes it difficult to develop a standardized treatment strategy for the primary tumor itself and for probable liver metastases. However, prolongation of the 5-year survival rate (5-ysr) and amelioration of the incapacitating symptoms after resection of the primary tumor and its metastases demonstrate that surgical intervention must be the treatment of choice in these tumors. METHODS: The data of 31 patients (17 patients with midgut carcinoids, 10 patients with an endocrine carcinoma (carcinoid) of the pancreas, and 4 patients with carcinoids of the lung) who underwent liver operation for metastatic carcinoid tumors between 1983 and 1996 were analyzed, with special regard to factors influencing postoperative survival. RESULTS: Ten patients underwent curative resection (5-ysr, 86%), and palliative operations were performed in 21 patients (5-ysr, 26%). The overall 5-ysr was 47%, with a mean postoperative follow-up of 3.5 years (range, 4 months to 10.8 years). Postoperative morbidity rate was 13%. Size of liver metastases, radicality of the operation and localization of the primary tumor were factors influencing postoperative survival. CONCLUSIONS: Surgery for metastatic carcinoid tumors may be curative or palliative, with a potential for cure in some cases and prolongation of survival and amelioration of symptoms in the majority of patients.

Adult↗
PubMed1999

[Assessment of the effective dose for routine protocols in conventional CT, electron beam CT and coronary angiography].

PURPOSE: To compare the effective dose applied by sequential CT (SEQ), spiral CT (SCT), electron beam CT (EBT) and coronary angiography for investigations of the chest, abdomen and the heart. METHODS: The Alderson Phantom was used to compare the effective dose for all modalities. In addition, the effective dose for conventional CT (SEQ and SCT) was estimated with a mathematical phantom. RESULTS: For CT investigation of the chest and abdomen the dose was highest for the EBT (11 mSv and 25 mSv, respectively) and slightly lower for the SEQ (7.8 mSv and 21.5 mSv, respectively), whereas spiral CT required the least dose (5.3 mSv and 8.8 mSv, respectively). For coronary calcium screening (0.8 mSv) and EBT coronary angiography (1.7 mSv) the dose was lower than for coronary catheter angiography (3.3 mSv). For conventional CT the difference between the effective dose derived by the mathematical phantom and by the Alderson phantom was 2% to 20%. CONCLUSIONS: For investigations of the chest and abdomen the effective dose applied by SCT is significantly lower than that with EBT and SEQ. For investigation of the coronary arteries the effective dose applied by EBT is lower than that for coronary catheter angiography.

Body Burden↗
PubMed1998

[Radiation exposure during CT examination of thorax and abdomen. Comparison of sequential, spiral and electron beam computed tomography].

Comparison of radiation exposure applied by different types of CT scanners for the investigation of the chest and abdomen. Determination of radiation exposure applied by multi-phase spiral CT. Estimation of the dose in air in the system axis of the scanner, the CT dose index (CTDI) and the effective dose for electron beam tomography (EBT) and two conventional CT scanners (sequence, SEQ; spiral, SCT). For EBT, dose in system axis for investigation of the abdomen was above 50 mGy. Effective dose for investigation of the chest and abdomen was higher with EBT (11 and 26 mSv, respectively) than with conventional CT (SEQ, 4 and 20 mSv; SCT, 2 and 7 mSv). The effective dose for a biphasic investigation (liver 5 mSv, kidney 4 mSv) was below, for a triphasic investigation (liver 7 mSv) above the effective dose of the investigation of the abdomen (6 mSv). Investigation of the abdomen with the EBT should only be performed for certain indications. With spiral CT, effective dose is much lower than with EBT.

Abdomen↗
PubMed1998

[Virtual colonoscopy using CT and MRI].

PURPOSE: To evaluate experimentally and in patients the sensitivity and effective dose of virtual electron-beam tomography (EBT) colonoscopy for detecting small colon tumors and to compare the methods and results with virtual colonoscopy using spiral CT and MR imaging in a review of the literature. MATERIALS AND METHODS: Six polyps with diameters between 3 and 12 mm were created and randomly placed in resected pig colon. After distension with air, the pig colon was scanned with continuous volume scanning (CVS, 3 mm collimation) and a pitch of 0.4, 0.8 and 1.5. Twenty patients positive for the fecal blood test were examined after rectal CO2 insufflation and i.v. administration of 1 mg glucagon. A 13 s CVS scan was used to cover the entire colon within one breath-hold. 3D volume-rendered fly-throughs were evaluated by two independent radiologists. Effective dose equivalent was estimated using an Alderson phantom equipped with thermoluminescence dosimeters. RESULTS: In the tumor model, all polyps were detectable at a pitch of 1.5. A further reduction of the pitch ratio did not improve the conspicuity of the polyps. In patient studies, all tumors (n = 4) and polyps (n = 3) were correctly identified on 3D fly-throughs. Two false positive results were obtained. Effective dose equivalent was calculated at 3.2 mSv per scan. CONCLUSIONS: Our preliminary results indicate that virtual EBT colonoscopy holds promise for fast screening for colon polyps. The best technique for virtual colonoscopy (Spiral CT, EBT, MRI) has not yet been determined and the future role of virtual colonoscopy must still be defined.

Colonic Polyps↗
PubMed1997

[Investigation of outer membrane proteins of Pasteurella. 2: Iron-regulated outer membrane proteins of Pasteurella multocida and Pasteurella haemolytica].

Pasteurella multocida and Pasteurella haemolytica produce specific proteins in the outer membrane under iron-depleted conditions. Pasteurella multocida serovar A expresses these proteins of molecular masses of 76 and 96 kDa as determined by electrophoresis. The analogous serovar D produces a further iron-regulated protein of 85 kDa. The Pasteurella haemolytica strains of serovar A1, A6 and T contain iron-regulated outer membrane proteins of molecular masses of 71, 77 and 100 kDa. These proteins possess binding positions for iron ions. Both Pasteurella multocida and Pasteurella haemolytica strains utilize iron from porcine and bovine transferrin, but not from haemin and haemoglobin.

Animals↗
PubMed1997

[Clonal analysis in cells using PCR and laser microdissection].

Clonality represents one of the hallmarks of neoplastic cell growth. X-chromosomal inactivation patterns have been used to determine clonality in various tumors. This approach is limited by admixture of polyclonal non-tumor stroma cells among which the monoclonal proliferation may be missed. In order to overcome this limitation, we combined a sensitive PCR based DNA analysis with a highly selective microdissection technique using a laser beam. In sections of intraductal mammary carcinomas tumor cell complexes of at least 100 cells were isolated by removing the surrounding stroma by laser irradiation. Thereby, tumor cells could be isolated without contaminating non-neoplastic elements. Clonality in these cells was determined using two X-chromosomal polymorphic sites-phosphoglycerate kinase 1 (PGK1) and human androgen receptor (HUMARA). Control experiments could show the polyclonal nature of the surrounding tissue. Moreover, complete destruction of DNA by laser irradiation was assured. The technique requires a certain amount of cells and DNA in order to avoid artefacts that result from preferential amplification of exclusively one X-chromosomal allele in small samples. We conclude that combination of laser-microdissection with PCR analysis of X-chromosomal inactivation patterns enables the detection of clonal cell populations in heterogeneous tissues. Studies of clonality in borderline cases between reactive and neoplastic proliferations or premalignant lesions are made possible by this technique.

Breast Neoplasms↗
PubMed1996

Postoperative irradiation treatment and bioresorbable implants in orthopaedic surgery: an experimental in vitro study.

The influence of applied radiation on the degradation of a polyglycolide (PGA) test specimen was studied in vitro. There was no significant difference in the time-dependent degradation behaviour between the irradiated test specimen and controls. Mandatory irradiation of an operation site following surgery therefore does not contradict the employment of bioresorbable implants in orthopaedic surgery.

Absorption↗
PubMed1996

[Total skin electron beam irradiation in cutaneous T-cell lymphoma].

PURPOSE: Patients with cutaneous T-cell lymphoma are treated in Germany mostly by dermatological local therapy like corticosteroids or PUVA-irradiation. Total skin electron beam irradiation is used rarely, even though it has a potentially curative character. We present an analysis of patients, who received a total skin electron beam irradiation after having progressive disease following other treatment modalities. PATIENTS AND METHODS: Twenty-one patients (mean age 58.9 years) in different stages were treated (stage IB and IIA n = 4, stage IIB n = 8, stage III n = 3, stage IV n = 6). All patients had progressive disease under other forms of local therapy. The irradiation was performed from 6 directions per hemibody using 2 axial fields which have each an 18 degree angle to the horizontal level. Six and 7 MeV fast electrons were used. Total dose was between 8 and 36 Gy in single dosis of 1 x 4 up to 5 x 2 Gy per week. In underdosed areas and areas of tumors of the skin boost irradiation with small fields was given. RESULTS: All patients had a good tumor regression (complete remission: n = 10, partial remission: n = 11). With the follow-up between 4 and 93 months total- and recurrence-free survival was 18 and 7 months (median). Patients in early stages with slow but complete remission of the symptoms had the best prognosis. Because of the small case number there was no significant difference between the groups. There were no severe side effects of the radiotherapy noted. CONCLUSION: Our analysis shows on a small patient number, that total skin electron beam irradiation has a good palliative effect on patients who have progressive disease following other types of treatment like PUVA or corticosteroids. The recurrence-free survival of 2 out of 4 patients with early stage disease (I-IIA) up to 93 month shows the potentially curative character of the treatment.

Adult↗
PubMed1995

[Proteins from the outer membrane of Pasteurella--1. Polyacrylamide gel electrophoresis of outer membrane proteins--a possibility for differentiation of Pasteurella haemolytica strains].

Using the sodium laurylsarcosinate method, outer membrane proteins (OMPs) of 63 Pasteurella haemolytica strains are isolated and their protein patterns obtained by SDS polyacrylamide gel electrophoresis (SDS-PAGE) are compared. A high degree of similarity became evident both within A and T biotypes in the molecular weight range of 25 to 50 KDa. Strain-to-strain variations are mainly limited to quantitative differences in individual protein bands. It is concluded that within both the A and T biotype groups equal sets of major proteins are present with differing amounts of individual constituents. Biotypes A and T can be clearly distinguished on the basis of marked variations in OMP profiles. OMPs of those AT strains included in comparative studies are exhibiting no general homogeneity, but a relative heterogeneity due to different protein compositions, which are, however, clearly distinct from the patterns of biotypes A and T. It is established unambiguously that isolates belonging to biotypes A or T, as well as AT strains, can be clearly distinguished from each other on the basis of SDS-PAGE analysis of OMP extracts. Thus, polyacrylamide gel electrophoresis of outer membrane proteins can be used for differentiation.

Bacterial Outer Membrane Proteins↗
PubMed1994

[Proliferative activity and defective replication in breast cancer].

The highly proliferating phenotype of mammary carcinoma is known to be associated with a particularly aggressive clinical course. We have been interested in the underlying molecular causes that give rise to the increased proliferative activity Proliferative activity was determined immunohistochemically by the detection of topoisomerase II-alpha (Ki-S1). The subgroup of highly proliferating tumors with a Ki-S1 index exceeding 30% was characterized by a high frequency of c-myc amplification and aberrant p53 expression, whereas tumors, with a low mitotic activity rarely exhibited gene amplification or an altered p53 expression. We conclude, that the highly proliferating phenotype is not capable of regular replication and tends to develop gene amplifications. One of the causes might be a defective cell cycle control by p53.

Breast Neoplasms↗
PubMed1993

Amplification of c-myc but not of c-erbB-2 is associated with high proliferative capacity in breast cancer.

Proliferative capacity provides an independent prognostic marker of progression in breast cancer. Little is known about the molecular mechanisms influencing the cell division rate in mammary carcinomas. In order to address this issue, the copy numbers of c-erbB-2 (HER/neu) and c-myc protooncogenes that have been shown to be amplified in aggressive types of cancers were determined in 60 mammary carcinomas and related to the proliferation rate. The proliferative activity was determined by labeling of the proliferation-associated nuclear antigen which is defined by the recently described monoclonal antibody Ki-S1. Approximately one-third of samples under investigation displayed a Ki-S1 labeling index exceeding 30%. In this subgroup, amplification of c-myc was found in 52.6%, whereas in the remaining cases, 26.1% exhibited an enhanced copy number of c-myc (P < 0.025). By contrast, c-erbB-2 amplification was not found to be associated with a higher proliferation index. Except for one case of invasive lobular carcinoma, both protooncogenes exhibited regular copy numbers in the low proliferation subgroup (< 20%; P < 0.03). We conclude from our findings that c-myc amplification may be one of the molecular causes underlying the highly proliferating phenotype of mammary carcinoma, known to be associated with an unfavorable clinical course.

Base Sequence↗
PubMed1993

Contrasting renal haemodynamic effects of protein in normal subjects and glomerulonephritic patients with impaired renal function.

The effects of a protein load on renal haemodynamics in patients with renal failure are controversial. We measured insulin clearance (Cin) and PAH clearance (CPAH) by constant infusion technique in six healthy subjects and 13 patients with biopsy-confirmed glomerulonephritis and chronic renal failure. The subjects were pre-equilibrated on their usual diet and studied before and 2 h after 1 g protein/kg as cooked red meat. In healthy subjects this caused a significant increase of Cin (from 136 +/- 7.2 (SD) to 148 +/- 7.9 ml/min/1.73 m2) and of CPAH (from 547 +/- 142 to 639 +/- 89). In contrast Cin decreased from 72.7 +/- 7.7 to 60.3 +/- 8.4 in patients with chronic renal failure, whereas CPAH showed no significant change (from 275 +/- 67.8 to 278 +/- 72.7). A similar decrease of Cin was also seen with acute infusion of amino acids (AA). The change in Cin was not related to changes of PRA or concentrations of plasma amino acids. While absolute and fractional Na excretion increased in controls, they decreased in patients in parallel with the decrease of Cin. The decrease of Cin after infusion of AA was amplified by pre-equilibration on low-sodium diet (20 mmol Na/day). The effect of meat ingestion on Cin was not obliterated, however, by pretreatment with captopril (25 mg b.i.d. for 7 days). In conclusion, in patients with chronic renal failure, a paradoxical decrease in Cin is seen both after oral protein and after amino-acid infusion.

Adult↗