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Biomedical subjects

R Maurer

Publications and source records attributed to R Maurer.

At least 73 records · Page 4Linked to original sources
PubMed1992

Effect of porcine somatotropin on number of granulosa cell luteinizing hormone/human chorionic gonadotropin receptors, oocyte viability, and concentrations of steroids and insulin-like growth factors I and II in follicular fluid of lean and obese gilts.

Prepubertal gilts of obese (n = 24) or lean (n = 24) genetic lines were injected (s.c.) daily with 0, 2, or 4 mg of porcine somatotropin (pST) for 6 wk starting at 160 d of age to determine whether pST affects follicular function. Blood and ovaries were collected at slaughter 24 h after the last injection. Surface follicles greater than or equal to 1.0 mm in diameter were counted, and pools of follicular fluid (FFL) and granulosa cells were collected from 1.0- to 3.9-mm (small) and 4.0- to 6.9-mm (medium) follicles. Oocytes were collected from small and medium follicles and evaluated for maturational stage and viability. Porcine somatotropin increased (P less than .08) the numbers of small but not the numbers of medium follicles per gilt (P greater than .10). Oocyte maturation and viability were not affected by pST or genetic line. Porcine somatotropin increased (P less than .05) concentrations of insulin-like growth factor I (IGF-I) in serum and FFL of both obese and lean gilts; IGF-I was lower (P less than .01) in lean gilts. Treatment with pST decreased (P less than .05) IGF-II in FFL of lean but not in that of obese gilts. Dose of pST and line had no effect on concentrations of progesterone in FFL of small or medium follicles or on concentrations of estradiol in FFL of small follicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[T-cell rich B-cell lymphoma associated with hemophagocytic syndrome].

Report of a T-cell rich B-cell lymphoma (TCRBCL) in a 43 years old man with an associated haemophagocytic syndrome (HS). At presentation the haemophagocytic cells involved the same organs as the lymphoma, i.e. spleen, liver, abdominal lymph nodes and bone marrow. As supportive measure to alleviate chemotherapy-induced granulocytopenia the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) was given. After an initial improvement of the blood granulocyte count pancytopenia developed again, resulting in fatal sepsis. Autopsy demonstrated massive proliferation of macrophages in the bone marrow with haemophagocytosis as morphological correlation to the pancytopenia. The observation that exogenous GM-CSF enhanced the preexistent HS primarily reactive to the TCRBCL raises the question if endogenous GM-CSF may play a role in triggering a HS. The observed association of TCRBCL and HS has not been reported so far.

Adult↗
PubMed1991

[Tumoral calcinosis with superinfection and sepsis].

Tumoral calcinosis (TC) is a rare syndrome involving ectopic calcifications in the vicinity of the large joints. In about one third of patients the disorder is familial and is associated with hyperphosphatemia, elevation of 1,25-dihydroxy-vitamin-D levels and peculiar dental lesion. TC is inherited in an autosomal-recessive manner. In a normophosphatemic male patient with alcoholic cirrhosis of the liver, TC occurred first in the thoracic wall. Seven years after excision of the first lesion, a large tumor mass around the right hip developed. Infection of the calcified masses with Staph. aureus led to extensive abscess formation, septicemia and death at the age of 64. Clinical, dental and biochemical examination of the 7 descendants of the patient revealed no constitutional signs of the disease, thus identifying our patient as a sporadic case. Clinical and pathological findings in the patient are discussed and the literature is reviewed.

Abscess↗
PubMed1991

[Interdisciplinary team work from the viewpoint of the medical oncologist].

Collaboration of specialists is a prerequisite for the modern care of cancer patients. The 'tumor board' plays a central role. As a rule, close to 10% of all cancer patients of a hospital are reviewed by this panel. Patho-anatomic questions are settled and therapeutic plans established. A cooperative case review shortens decision paths, and therapeutic procedures are supported by all the participating specialists. The tumor board is also appreciated by postgraduate education, and it facilitates the introduction of oncologic thinking in the general hospital. For the specialist the incentive is to provide insight into his field, to expose advantages or weaknesses of his therapeutic modalities and to adapt them to the special needs of a particular patient.

Humans↗
PubMed1991

Requirements for bypass of UV-induced lesions in single-stranded DNA of bacteriophage phi X174 in Salmonella typhimurium.

According to the current model for mutagenic bypass of UV-induced lesions, efficient bypass requires three proteins: activated RecA (RecA*) and either activated UmuD (UmuD') and UmuC or their plasmid-encoded analogues, MucA' and MucB. RecA* aids synthesis of UmuD' and UmuC (and MucA'/MucB) at two levels: by inactivation of the LexA transcriptional repressor of these genes and by cleavage of UmuD (and MucA) to produce the active fragments, UmuD' (MucA'). A third role for RecA is revealed when these two roles are otherwise satisfied in a suitably engineered strain. An often-suggested possible role for RecA in bypass is inhibition of editing by the epsilon subunit of DNA polymerase III. Here, by demonstrating that elimination of epsilon by deletion of its gene, dnaQ, does not relieve the requirement for the third function of RecA, we show that RecA must perform some function other than, or in addition to, inhibition of epsilon. We also show that elimination of epsilon does not relieve the requirement for either Muc protein. Moreover, we observed reactivation of irradiated phi X174 in unirradiated cells expressing MucA' and MucB. This finding makes it unlikely that the additional role of recA involves derepression of an unidentified gene or cleavage of an unidentified protein and makes it more likely that RecA participates directly in bypass.

Bacterial Proteins↗
PubMed1991

Platelet aggregation inhibiting and anticoagulant effects of oligoamines, XVI: Cytostatic and cytotoxic side effects of oligoamines.

Selected synthetic oligoamines were able to inhibit (IC50) the growth of leukemic L 1210 cells in concentrations between 4-10 mumol/L. The essential structural features were at least two basic nitrogen functions in suitable distance, substituted with arylalkyl or alkyl groups. The favorable chain length is about eight carbon atoms. The cytostatic effect is complete after 30 min and cannot be washed out with buffer. Viability measurements showed that the leukemic cells were killed in a time dependent manner. As no influence on the cell nucleus could be observed this is most probably due to interaction with the cell membrane. When high local concentrations are applied in vivo, the oligoamines are toxic because of cytolytic properties. This toxicity can be overcome by administration of suitable prodrugs (LD50 greater than 1000 mg/kg).

Animals↗
PubMed1991

Solid-cystic (papillary-cystic) tumours within and outside the pancreas in men: report of two patients.

Solid-cystic (papillary-cystic) tumours (SCT) of the pancreas are distinctive neoplasms with a predilection for young female patients. This is the first detailed report describing the occurrence of SCT in two young male patients. Except for the extapancreatic occurrence of one of the tumours (in the retroperitoneal region behind the head of the pancreas), all other clinicopathological features were identical to those characterizing the SCT in women. Immunostaining was (at least focally) positive for Lu 5 (broad spectrum keratin marker), vimentin and alpha-1-antitrypsin. The tumours were negative for neuroendocrine markers (except for neuron-specific enolase), pancreatic hormones and enzymes, pancreatic stone protein, carcinoembryonic antigen, CA 19-9 and nuclear oestrogen and progesterone receptors. This report does not support the suggested female sex hormone dependence of SCT.

Adult↗
PubMed1991

Perhexiline maleate-induced hepatitis.

We report on a case of perhexiline maleate-induced hepatitis secondary to a long-term administration of recommended daily dosages of 300 mg. The patient had a spectacular weight loss of 29 kg. He developed hepatitis, which subsided after drug withdrawal. Our electron-microscopic findings with the typical inclusion bodies and impaired hydroxylation capacity point to an underlying metabolic disorder as the pathogenetic mechanism.

Angina Pectoris↗
PubMed1990

Enhancing the impact of visual extra-maze cues in a spatial orientation task.

In a short-distance homing task, golden hamsters derive the homing direction both from visual extra-maze cues and from the integration of the outward journey. The relative importance of visual configurations in the control of homing was assessed by presenting these cues in conflict with path integration. The hamsters depended mainly on path integration during the presentation of 3 objects at the periphery of the experimental arena or of a background pattern which surrounded the arena at a certain distance. However, they switched to visually controlled behaviour when the objects were superimposed on the patterned background. The possibility is discussed that the enhancement of the depth dimension through the simultaneous presentation of a foreground and a background may increase the effectiveness of visual cues in spatial orientation.

Animals↗
PubMed1989

Isolation and characterization of mutants with deletions in dnaQ, the gene for the editing subunit of DNA polymerase III in Salmonella typhimurium.

dnaQ (mutD) encodes the editing exonuclease subunit (epsilon) of DNA polymerase III. Previously described mutations in dnaQ include dominant and recessive mutator alleles as well as leaky temperature-sensitive alleles. We describe the properties of strains bearing null mutations (deletion-substitution alleles) of this gene. Null mutants exhibited a growth defect as well as elevated spontaneous mutation. As a consequence of the poor growth of dnaQ mutants and their high mutation rate, these strains were replaced within single colonies by derivatives carrying an extragenic suppressor mutation that compensated the growth defect but apparently not the mutator effect. Sixteen independently derived suppressors mapped in the vicinity of dnaE, the gene for the polymerization subunit (alpha) of DNA polymerase III, and one suppressor that was sequenced encoded an altered alpha polypeptide. Partially purified DNA polymerase III containing this altered alpha subunit was active in polymerization assays. In addition to their dependence on a suppressor mutation affecting alpha, dnaQ mutants strictly required DNA polymerase I for viability. We argue from these data that in the absence of epsilon, DNA replication falters unless secondary mechanisms, including genetically coded alteration in the intrinsic replication capacity of alpha and increased use of DNA polymerase I, come into play. Thus, epsilon plays a role in DNA replication distinct from its known role in controlling spontaneous mutation frequency.

Cloning, Molecular↗
PubMed1989

Nucleotide sequences of dnaE, the gene for the polymerase subunit of DNA polymerase III in Salmonella typhimurium, and a variant that facilitates growth in the absence of another polymerase subunit.

The dnaE gene of Salmonella typhimurium, like that of Escherichia coli, encodes the alpha subunit containing the polymerase activity of the principal replicative enzyme, DNA polymerase III. This gene, or one nearby, has been identified as the locus of suppressor mutations that promote growth by cells deleted for dnaQ, the gene for the editing subunit of this enzyme complex. Using a combination of nucleotide sequencing and marker rescue experiments, the alteration in one such suppressor was identified as a valine-to-glycine substitution at amino acid 832 of the 1,160-amino-acid alpha polypeptide. The alpha polypeptides of E. coli and S. typhimurium are identical in size and in 97% of their amino acid residues. Their identity includes the valine residue that was changed in the suppressor allele of S. typhimurium. We also localized a temperature-sensitive dnaE mutation to the 3' half of dnaE.

Amino Acid Sequence↗
PubMed1989

[Angiosarcoma following teratocarcinoma: "mutation", successive malignancy or irradiation].

Angiosarcoma is a rare malignant soft-tissue tumor and affects preferably skin and adjacent subcutaneous tissue. Very rarely the tumor is radiation-induced. We report the case of a 28-year-old Swiss who developed an angiosarcoma of the gut 5 years after the successful therapy of metastasising teratocarcinoma of his right testis by surgery and radiation therapy. We discuss three possible etiologies for the genesis of the angiosarcoma, which appeared rapidly after the primary tumor at an unusual site in an unusual patient.

Adult↗
PubMed1988

Occurrence of pharmacologically active benzodiazepines in trace amounts in wheat and potato.

Aqueous acid extracts of wheat grains and of potato tuber were found to contain a series of compounds displaying a high affinity to the central type benzodiazepine receptor (BZR) in mammalian brain. Further analysis using different HPLC systems, as well as mass spectrometry and gas chromatography combined with mass spectrometry lead to the identification of compounds belonging to the classical 5-phenyl-1,4-benzodiazepinones. In wheat grains diazepam, N-desmethyldiazepam, delorazepam, deschloro-diazepam, delormetazepam, lormetazepam and isodiazepam were identified, while potato tuber contained diazepam, N-desmethyldiazepam, delorazepam, lorazepam and delormetazepam. The concentration of the benzodiazepines (BZ) was in the low ppb range. Their biosynthesis most probably takes place in the plant tissue. The availability of BZs in plant nutritives points to a possible source for the previously reported presence of BZ in brain and peripheral tissues of several animal species and man.

Animals↗