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Biomedical subjects

A Werner

Publications and source records attributed to A Werner.

At least 235 records · Page 13Linked to original sources
PubMed1989

Nucleotide concentrations in hepatocytes during anoxia and reoxygenation in presence of allopurinol and oxypurinol.

In hepatocytes of starved rats nucleotide, nucleoside and nucleobase concentrations were measured during and following anoxia. A complete restoration of ATP is observed during reoxygenation after anoxic periods less than 60 minutes. GTP cannot be completely restored after 30 minutes of anoxia. Allopurinol and oxypurinol do not accelerate the ATP and GTP restoration. IMP, adenosine and AMP concentrations are increased in presence of allopurinol or oxypurinol during anoxia and reoxygenation.

Adenosine Triphosphate↗
PubMed1989

Changes in the nucleotide metabolism of Ehrlich ascites tumour cells during their growth in vivo.

During the transition of Ehrlich mouse ascites tumour cells from the proliferating into the resting phase of growth a tremendous loss of purine and pyrimidine compounds was quantitated by ion-pair reversed-phase high performance liquid chromatography. This change is accompanied by a distinct decline in the incorporation rates of adenine, hypoxanthine, and adenosine. Inorganic phosphate stimulates the low rate of hypoxanthine incorporation of cells in the plateau phase, but lacks any effect on the high rate during proliferation. The mitochondria suffer structural deteriorations and decrease in their cellular content in the course of the plateau phase; however, other changes were not seen by morphometric analysis. The interrelations between nucleotide metabolism, mitochondrial content and the rates of formation and consumption of ATP are discussed.

Adenine↗
PubMed1988

Purine and pyridine nucleotides in rabbit red blood cells of different maturity.

Using reversed-phase high-performance liquid chromatography purine nucleotides, nucleosides and nucleobases as well as pyridine nucleotides were determined in extracts of reticulocytes and mature red blood cells of rabbits. The concentrations of almost all compounds measured decrease during the last phase of red blood cell maturation. These changes were interpreted with respect to the loss of mitochondria, accompanied by shifting the energy production from the preferentially oxidative mode to the exclusively glycolytic one and variations in the concentrations of purine compounds in blood plasma during reticulocytosis.

Adenine Nucleotides↗
PubMed1988

[Immunocytochemical detection of the estrogen receptor and lectin binding sites in tumor cell colonies growing in vitro].

Since it became clear that tumor cell colonies growing in soft agar are closely related to embryonic tumor cells, it has been possible to examine, with the aid of immunohistochemical methods, the behavior of estrogen receptors (ER) and lectin binding sites on those tumor components which determine malignant growth. With this aim in mind, 14 breast cancers, four ovarian cancers, and one corpus cancer with ER concentrations known from DCC studies were cultured in a colony assay. Using immunohistochemical techniques it was possible, after preparing permanent cultures, to demonstrate the estrogen receptors and lectin binding sites on the tumor cell colonies cultured in vitro.

Breast↗
PubMed1988

[Tolerance of intraoperative, intraperitoneal chemotherapy in advanced gynecologic malignancies].

Assuming that cells and portions of tumor may remain in the abdominal cavity after surgery to reduce tumor size in cases of ovarian carcinoma, and that a change in cell kinetics could result in accelerated growth in the event of a recurrence, 23 patients with advanced tumors were given local (intraperitoneal) treatment intraoperatively. The treatment consisted of 15 mg Mitomycin C or 30 or 40 mg of Mitoxantron, in 1000 ml normal saline. Since the observation time was so short, the tolerance and side effects of this form of treatment were of primary interest, rather than remission quotas and survival times. The principal abdominal complaints included two subileus conditions which responded well to therapy and the problem of postoperative nausea. Four patients reacted to the treatment described with temperatures of over 38 degrees C. Chemical changes detected in the laboratory included 18 cases of leukopenia, which in one case reached WHO Grade 4. Intermittent changes in liver values and electrolytes were observed in isolated cases. Wound-healing impairments occurred in three cases. In one of them, a patient who sustained a prolapse of the small intestine with tumor growth into the abdominal wall, reoperation was necessary. Taken overall, the side effects of the intraoperative, intraperitoneal cytostatic therapy were acceptable. In view of the courses observed and with the idea of employing a form of therapy to combat aggressive growth of tumor cells remaining after surgery, it appears justified to continue with this form of treatment.

Adolescent↗
PubMed1988

Ovarian stimulation using pure FSH in an in-vitro fertilization programme.

The therapeutic efficacy of stimulating ovarian follicular development by pure urinary FSH in an IVF programme was determined and compared with results of other therapeutic regimens. Forty-three patients selected for extracorporeal fertilization were treated with pure FSH after stimulation with clomiphene or HMG had proved to be unsuccessful. Treatment had to be discontinued in five patients before follicular puncture, and embryo transfer was performed in 32, of whom seven conceived. FSH stimulation evidently creates favourable conditions for in-vitro fertilization in patients with impaired follicular maturation following conventional stimulation with clomiphene or HMG. Levels of oestradiol, progesterone and androstenedione were measured in follicular fluid, and high progesterone concentrations were correlated with mature oocytes. The increased ratios of progesterone/androstenedione and progesterone/oestradiol in follicles containing mature oocytes are due to the onset of luteinization of mature follicles as a consequence of HCG administration.

Androstenedione↗
PubMed1988

[Experiences with PAC and PEC polychemotherapy in the treatment of advanced and recurrent breast cancers].

At the department of gynecology of the universities of Lübeck and Bonn 18 in part pretreated patients with advanced or relapsing cancer of the breast were treated with a DDP-containing polychemotherapy. For 14 of the 18 women the PAC or PEC regime was beneficial: 9 had complete or partial remission and 1 patient had a no change situation; 4 women showed no evidence of disease. The time of survival after the chemotherapy treatment was two month in the minimum and more than 50 month in the maximum (20 month in the average). As side effects, in particular leucocyte-depression and nausea as well as vomiting of various degrees were observed; alopecia was seen in every case. The success of DDP-containing chemotherapy in the treatment of breast cancer is of note, but in the future it will be important to define subgroups that would most benefit from PAC- or PEC-treatment without substantial negative side effects.

Adult↗
PubMed1988

Color constancy in the honeybee.

A multicolored display was illuminated by 3 bands of wavelengths corresponding to the maxima of the spectral sensitivities of the 3 types of photoreceptors found in the bee retina. The intensity of each band could be varied individually. The light fluxes emitted by the colored areas of the multicolored display were determined quantitatively. Free-flying honeybees were trained with sugar solution to choose one of the colored areas. The illumination was then changed in such a way that the light fluxes formerly emitted by the training area were now measured on another area. When the trained bees were tested under those conditions, they still chose the training area. The relative positions of the colored areas were changed in order to exclude learning of position. It is concluded that color vision in bees is, in a certain range, independent of the spectral content of the illumination. Model calculations show that the behavior observed in bees is consistent with the retinex theory (Land, 1977), i.e., an algorithm using long-range interactions is required to explain color constancy.

Animals↗
PubMed1987

Determination of nucleotides, nucleosides and nucleobases in cells of different complexity by reversed-phase and ion-pair high-performance liquid chromatography.

Procedures are presented for the analysis of profiles of purine and pyridine compounds in human and rabbit red blood cells by reversed-phase high-performance liquid chromatography and in Ehrlich ascites tumour cells of mouse by ion-pair high-performance liquid chromatography. These compounds are present in rabbit erythrocytes in higher concentrations than in human blood cells, and in rabbit reticulocytes the concentration of purine compounds is still higher. During glucose-free incubation, human red cells accumulate adenosine and adenine in the presence of coformycin owing to the inhibition of adenosine and AMP deamination. Ehrlich ascites tumour cells lose major portions of purine mono-, di- and triphosphates between the seventh and eleventh day after inoculation into mouse peritoneal cavities.

Animals↗
PubMed1987

Naltrexone decreases self-injurious behavior.

The effect of naltrexone (0.5, 1.0, 1.5, and 2.0 mg/kg) on the frequency of self-injurious behavior (SIB) was investigated in three male adolescents. The frequency of total SIB was reduced significantly in all three subjects; dose-dependent decreases (at 0.5, 1.0, and 1.5 mg/kg) in SIB frequency were observed in the two mentally retarded subjects. These data suggest a role for opioid peptides in SIB.

Adolescent↗
PubMed1987

The palliative efficacy of a single high dose of radiation in treatment of symptomatic osseous metastases.

Radiation therapy is effective for palliation of painful metastatic osseous lesions. Various fractionation doses have been previously described. The present study was initiated to evaluate the efficacy of a high single dose of radiation on pain relief, with the goal of reducing the number of radiation sessions to a minimum. Treatment consisted of a high single dose of radiation ranging between 6 to 10 Gy administered to painful osseous metastases. Prior to radiation therapy response to conservative analgesic therapy was minimal in most cases. Response to radiation therapy thereafter was 71.3% lasting up to 6 and 12 months in 37.3% and 20.9% of cases respectively.

Adolescent↗
PubMed1987

Synthesis and structure-activity relationships of potent new angiotensin converting enzyme inhibitors containing saturated bicyclic amino acids.

The synthesis of a series of novel, potent angiotensin converting enzyme (ACE) inhibitors containing saturated bicyclic amino acids in place of proline is described. Octahydroindole-2-carboxylic acid, octahydroisoindole-1-carboxylic acid, and octahydro-3-oxoisoindole-1-carboxylic acid can replace proline in both sulfhydryl and non-sulfhydryl ACE inhibitors to give compounds equipotent to captopril and enalapril both in vitro and in vivo. Structure-activity relationships are discussed. Compound 11a (CI-907, indolapril) has advanced to clinical evaluation.

Amino Acids↗
PubMed1987

[Ovarian stimulation with pure FSH in an in vitro fertilization program].

The therapeutic efficacy of stimulating ovarian follicular development by pure urinary FSH in an IVF programme was determined and compared with results of other therapeutic regimes. 43 patients selected for extracorporeal fertilization were treated with pure FSH after stimulation with clomiphene or HMG had proven not be successful. Only in 5 patients (12%) treatment had to be discontinued before follicular puncture. In 32 women an embryo transfer was performed, and 7 patients conceived. This result demonstrates that, applying pure FSH stimulation, favourable conditions can be created for an in-vitro fertilization in patients with impaired follicular maturation following conventional stimulation with clomiphene or HMG. On the strength of the values determined for progesterone and estradiol during the luteal phase one has to conclude that a normal corpus luteum function was achieved in all our patients following FSH-stimulation.

Embryo Transfer↗