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Biomedical subjects

N Fuchs

Publications and source records attributed to N Fuchs.

32 records · Page 2Linked to original sources
PubMed1995

The effect on blood pressure of a monophasic oral contraceptive containing ethinylestradiol and gestodene.

To obtain an overview of the effect of monophasic gestodene on blood pressure and to determine the frequency of "OC elevated BP/hypertension," the results of blood pressure monitoring from four clinical studies of contraceptive efficacy and safety have been retrospectively analyzed. A total of 1930 women took part in the studies, which recorded BP for up to 24 cycles. Analysis of results revealed that 97 women (5.0%) showed an increase in blood pressure from previously normal to elevated values while taking monophasic gestodene, with only 26 (1.35%) fulfilling the criteria of "OC elevated BP/hypertension." Only four women dropped out of the trials due to hypertensive blood pressure values, while 67 women (3.5%) experienced a normalization of previously elevated blood pressure measurements. In conclusion, this analysis has confirmed that gestodene has a negligible effect on blood pressure, with increased BP a relatively rare event.

Adolescent↗
PubMed1994

Methotrexate pharmacokinetics and prognosis in osteosarcoma.

PURPOSE: The influence of methotrexate (MTX) pharmacokinetic parameters on the efficacy of high-dose MTX (HDMTX) in osteosarcoma was analyzed. PATIENTS AND METHODS: MTX serum peak values from 198 patients in 1,703 treatment courses and more detailed pharmacokinetic data from 185 patients in 1,045 treatment courses from the Cooperative Osteosarcoma Study Group (COSS) studies COSS-80, COSS-82, and COSS-86 were investigated. RESULTS: A mean threshold peak level of > or = 1,000 mumol/L for the repeated MTX courses of individual patients was found to correlate significantly to prognosis in study COSS-80 (18% v 64% actuarial 10-year disease-free survival [DFS], P = .0001). Six courses of HDMTX per patient who achieved peak values > or = 1,000 mumol/L were found to be sufficient for a full effect to be seen in DFS in COSS-80. The MTX peak level was found to correlate closely to the area under the curve (AUC). However, AUC was a less powerful determinator of prognosis than the mean threshold MTX peak value. In patients who received cisplatin (DDP) as one of the additional drugs to MTX, the peak values and AUC were significantly increased (1,396 v 1,276 mumol/L, P = .011; 6,684 v 5,820 h.mumol/L, P < or = .002) and only a few patients (6%) did not achieve mean threshold MTX peak values. In addition, following restriction of hydration fluid after the MTX infusion from 4.5 to 3.0 L/m2 per 24 hours, the early MTX half-life (t1/2) and the AUC, but not the MTX peak value, were significantly increased (3.4 v 3.05 hours, and 6,760 v 5,998 h.mumol/L, respectively, P < or = .002). CONCLUSION: MTX pharmacokinetics significantly influence the efficacy of MTX in osteosarcoma. Individual adaptation of the MTX dose to ensure a threshold peak serum level > or = 1,000 mumol/L does not seem necessary at a fixed dose of 12 g MTX/m2, restriction of hydration fluid to 3 L/m2 per 24 hours, and concomitant use of DDP within the drug regimen.

Actuarial Analysis↗
PubMed1993

Osteosarcoma.

Findings from molecular genetic and cytogenetic investigations suggest that mutations in suppressor genes play a key role in osteosarcoma pathogenesis. RB and p53 are frequently involved and are speculated to be indispensable components. Alterations in putative suppressor genes on chromosomes 18q and 3q additionally may be involved in various patterns. The high resolution of magnetic resonance imaging in osteosarcoma imaging is confirmed, and the validity of dynamic gadolinium-enhanced imaging for estimation of tumor response is stated. The efficacy of single-drug high-dose methotrexate convincingly is shown to be 19%. Phase II trials with nonspecific immunostimulation using a synthetic liposomal mycobacterium-derived antigen (liposomal muramyl tripeptide phosphatidylethanolamine) do not yet allow us to draw conclusions on eventual efficacy. A novel and promising approach may be intervention in the endocrine or orthocrine and paracrine tumor growth regulation. Hypophysectomy in mice dramatically reduced plasma or insulin-like growth factor and local as well as systemic growth of transplanted osteosarcoma. The close interrelation between tumor response, surgical margins, and local control is demonstrated, as well as the fatal prognosis after local failure. Also, the validity of known risk factors in patients undergoing intensive chemotherapy has been confirmed. Interestingly, dose intensity was not found to influence prognosis.

Humans↗
PubMed1992

Pharmacokinetics of fluorescent polyporphyrin Photofrin II in normal rat tissue and rat bladder tumor.

The transient behavior of the molecular components responsible for fluorescence emission of the photosensitizing polyporphyrin Photofrin II has been studied quantitatively in the liver, small intestines, bladder and muscles of rats. Relative concentrations of the substance were determined fluorometrically in vivo using a Kr(+)-laser (wavelength = 406.7 nm) and a mercury arc lamp (wavelength = 405 or 550 nm) for fluorescence excitation of Photofrin II. Fluorescence was detected at the maxima of the emission bands, at 630 or 690 nm. The results of the experiments show that Photofrin II can be clearly detected by its fluorescence in all the organs investigated from 3 h up to at least 28 days after systemic application of the substance. Within this investigational period the fluorescing components of Photofrin II are released continuously from the organs. In all the tissues examined, an initial decrease with time constants between 2 and 42 h followed by a slow decay with time constants between about 300 and 600 h can be observed. In addition the pharmacokinetics of the fluorescent components of Photofrin II in chemically induced rat bladder tumors with different stages of malignancy were compared to healthy rat bladder tissue. In a time range of 2-10 days after intravenous injection Photofrin II shows a fluorescence 2-5 times brighter in rat bladder tumors than in healthy bladder tissue.

Animals↗
PubMed1992

Mutation and mapping of genes involved in production of the antibiotic TA in Myxococcus xanthus.

Transposition of TnV and Tn5lac into Myxococcus xanthus yielded 8,381 kanamycin-resistant mutants that were tested for antibiotic TA production. Twenty-four of the mutants were nonproducers of TA (less than 0.4 ng/ml), and 3 produced a higher level (2.5 micrograms/ml) than the parent strain (1.5 micrograms/ml). For most of the strains, there was 100% cotransduction between kanamycin resistance and the altered TA phenotype. Southern blot analysis of restriction digests of the mutant DNA indicated that the transposons were inserted at different sites on the M. xanthus chromosome. The TA genes were mapped by cotransduction between pairs of mutants following replacement of the initial insert of one of the pair with the tetracycline resistance transposon Tn5-132. Nine of the 13 nonproducers tested were linked over a 36-kb stretch of the chromosome. There was no linkage between one of the overproducers and any of the nonproducers tested.

Anti-Bacterial Agents↗
PubMed1992

Use of Tn5lac to study expression of genes required for production of the antibiotic TA.

The beta-galactosidase activities arising from Tn5lac insertions in several genes required for antibiotic TA production were measured under different growth conditions. In all of the non-TA-producing mutants, the beta-galactosidase specific activity was higher when the cells were grown in nutrient-limited 0.5CTS medium (0.5% Casitone plus alanine, serine, and glucose) than in rich 2CT medium (2% Casitone). One of the mutants, 420, had low beta-galactosidase specific activity in both media. The other seven mutants containing inserts in genes essential for TA production had specific activities of 139 to 367 U/mg of protein in 0.5CTS medium and 11 to 48 U/mg of protein in 2CT medium. The beta-galactosidase specific activities of two strains, 1030 and 420, increased during exponential growth in 0.5CTS medium. The beta-galactosidase specific activities of both strains increased greatly when the cells were grown in the presence of magnesium phosphate, which traps ammonium ions. The Tn5lac insertions in 1030 and 420 were used to screen for mutants with increased levels of transcription. An N-methyl-N'-nitro-N-nitrosoguanidine-induced mutation in 1030 that mapped 17 kb from the omega 1010 insert increased the specific activity of beta-galactosidase 21 times in 2CT medium. The regulatory mutation appears to release the repression caused by 2CT medium. A UV-induced mutation in 420 increased the beta-galactosidase specific activity 1.4 to 2.4 times. Medium conditions that affect the transcription of TA genes are discussed in terms of enhanced antibiotic TA production.

Anti-Bacterial Agents↗
PubMed1989

[The ultrasonic demonstration of gas in the endometrial cavity--an aid for the diagnosis of puerperal endometritis].

A pilot study was undertaken to determine the prevalence of gas in the puerperal endometrial cavity and to determine whether this finding has any relationship to the mode of delivery or to the development of puerperal endometritis. On the first day after delivery 192 patients were examinee ultrasonographically and gas was demonstrated in 26 (13.54%). Gas was found significantly more often in relation to caesarean section and intra-uterine manipulation than in normal vaginal deliveries (P less than 0.0001). On the third puerperal day the gas disappeared in 12 patients but persisted in 14, of whom 7 had signs of endometritis. Endometritis was diagnosed in a total of 8 patients and only 1 did not have signs of gas in the endometrial cavity. Although the figures are small it is concluded that ultrasonography of the puerperal uterus might assist in the diagnosis of puerperal endometritis.

Adolescent↗
PubMed1989

[Fluorescence diagnosis of porphyrin-marked urothelial tumors. Status of experimental development].

On the basis of selective storage of fluorescing hematoporphyrin derivative (HpD) in tumors, a method has been developed that enables the endoscopic detection of early-stage cancer by monitoring fluorescent images. The contrast-reducing portion of the superposed tissue autofluorescence is suppressed by the use of two-wavelength excitation and subsequent image processing in realtime. The amount of photosensitizing HpD necessary for diagnostic purposes is considerably reduced by means of sensitive detection devices. A clear distinction between benign and malignant bladder tissue seems possible according to the results of animal studies.

Animals↗
PubMed1975

Virus isolation and titration at 33 degrees and 37 degrees C.

Various prototype viruses and original specimens were comparatively titrated in cell cultures at 33 degrees and 37 degrees C. Higher titers at 37 degrees were consistently obtained with adenoviruses; for other viruses (enteroviruses, herpesvirus hominis, vaccinia virus, parainfluenza viruses) the titers were mostly identical at either temperature. Original specimens and prototye strains showed the same behavior. The habit to cultivate viruses from throat swabs at 33 degrees C is unsatisfactory for adenoviruses.

Adenoviridae↗
PubMedDate not supplied

[The prognostic significance of tumor volume in osteosarcoma with neoadjuvant chemotherapy].

In a retrospective analysis on 128 patients from the trials COSS-80, -82, -85 and -86 initial x-ray pictures were evaluated for tumor diameters in three planes and the prognostic meaning on survival was assessed. In a subset of patients (n = 27) the measured values were compared to values obtained by CT-Scan and a good correlation (r = 0.69) was found. Several parameters for tumor size were defined: absolute tumor length (ATL), relative tumor length (RTL, proportion of tumor to the length of the involved bone), absolute tumor volume (ATV, calculated by the ellipsoid formula) and relative tumor volume (RTL, tumor volume referred to the body surface area) and univariate and multivariate survival analysis were performed. Univariate analysis of metastasis free survival (MFS) revealed a high prognostic significance of the ATL, the ATV and the RTV. The RTL in this patient group demonstrated a tendency only toward an inferior prognosis in larger tumors. None of the patients with a ATV < 70 ml (n = 19) and only one of 33 patients with an ATV < 100 ml relapsed. Cox regression analysis was performed including the variables age, sex, site and response (> 90% tumor necrosis) in 84 patients. ATL and RTL do not enter the model, while the response proves its significance as a valid prognostic factor with a p-value of 0.0004. Adding the ATV as the measure of tumor size to the model it enters as the first term (p = 0.0000) followed by the response (p = 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Neoadjuvant therapy for localized osteosarcoma of extremities. Results from the Cooperative osteosarcoma study group COSS of 925 patients].

BACKGROUND: Owing to twenty years of multicentric interdisciplinary cooperation, the COSS group has been able to collect data on a large group of osteosarcoma patients treated by neoadjuvant therapy. This paper reviews results achieved in patients with localized extremity tumors. PATIENTS AND METHODS INCLUSION CRITERIA: Registration into a completed neoadjuvant COSS-Study. Histologically confirmed, primary, localized, high-grade, central osteosarcoma of an extremity; age < 40 years; no pretreatment; interval diagnosis to chemotherapy < or = 3 weeks; no severe comorbidity. Chemotherapy: HD-methotrexate +/- doxorubicin +/- cisplatin +/- ifosfamide +/- BCD. Scheduled local therapy: Surgery. RESULTS: 925 evaluable patients from 101 institutions. Median age 15 years, m:f 1.4:1. Primary site: femur 510, tibia 251, humerus 100, fibula 51, other 13. Tumor-size < 1/3 of the involved bone 616, > or = 1/3 304. Definitive surgery in 903/925 cases, 443 limb salvage procedures. Good response (> 90% necrosis) in 469/806 (58.2%) evaluated tumors. Median follow-up for surviving patients: 5.42 years. Actuarial survival after 5 and 10 years: 72.5% (95%-CI 69.3-75.7) and 66.3% (62.5-70.0), relapse-free 62.1% (58.7-65.4) and 59.4% (55.8-63.0). 683/925 alive (601 first remission), 242 deceased (212 tumor progression, 30 other causes). 66.2% (97.3%) of all relapses within 2 (5) years. Prognosis correlates with tumor-size (< vs. > or = 1/3: 69.9% vs. 58.3% at 10 years) and -site (tibia: 74.2%, humerus: 54.5%) and -response (good vs. poor: 78.2% vs. 52.5%) (all p < 0.01). Actuarial 10-year survival by response grading I-VI according to Salzer-Kuntschik 80.9%, 82.8%, 71.1%, 60.7%, 47.7%, 27.3%. COSS-studies with preoperative 4-drug therapy more efficacious than less aggressive protocols. No impact of doxorubicin scheduling (sequential: rapid vs. 48 h-continuous infusion) or cisplatin scheduling (randomized: 5 h vs. 72 h-infusion) on prognosis detected. CONCLUSIONS: Intensive multiagent chemotherapy and delayed surgery for localized extremity osteosarcoma led to excellent oncologic results in the COSS-studies. Tumor-size, -site, and -response as well as the intensity of upfront chemotherapy correlated with outcome. Giving doxorubicin and cisplatin by continuous infusions did not result in discernible prognostic disadvantages.

Adolescent↗