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Biomedical subjects

M Koller

Publications and source records attributed to M Koller.

At least 19 recordsLinked to original sources
PubMed1992

Characterization of the human calmodulin-like protein expressed in Escherichia coli.

The protein-coding region of an intronless human calmodulin-like gene [Koller, M., & Strehler, E. E. (1988) FEBS Lett. 239, 121-128] has been inserted into a pKK233-2 expression vector, and the 148-residue, M(r) = 16,800 human protein was purified to apparent homogeneity by phenyl-Sepharose affinity chromatography from cultures of Escherichia coli JM105 transformed with the recombinant vector. Several milligrams of the purified protein were obtained from 1 L of bacterial culture. A number of properties of human CLP were compared to those of bacterially expressed human calmodulin (CaM) and of bovine brain CaM. CLP showed a characteristic Ca(2+)-dependent electrophoretic mobility shift on SDS-polyacrylamide gels, although the magnitude of this shift was smaller than that observed with CaM. CLP was able to activate the 3',5'-cyclic nucleotide phosphodiesterase to the same Vmax as normal CaM, albeit with a 7-fold higher Kact. In contrast, the erythrocyte plasma membrane Ca(2+)-ATPase could only be stimulated to 62% of its maximal CaM-dependent activity by CLP. CLP was found to contain four Ca(2+)-binding sites with a mean affinity constant of 10(5) M-1, a value about 10-fold lower than that for CaM under comparable conditions. The highly tissue-specifically-expressed CLP represents a novel human Ca(2+)-binding protein showing characteristics of a CaM isoform.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

Characterization of two novel human retropseudogenes related to the calmodulin-encoding gene, CaMII.

Two human genomic clones (lambda hg22 and lambda hg29), containing two novel calmodulin (CaM) retropseudogenes, were isolated and characterized. The two pseudogenes show high similarity with the human CaMII cDNA, hCE1 [SenGupta et al., J. Biol. Chem. 262 (1987) 16663-16670] and the CaMII-type retropseudogene, hCE2 (CaMII-psi 1) [SenGupta et al., Nucleic Acids Res. 17 (1989) 2868]. One of them, in clone lambda hg22 (CaMII-psi 2), shows all the characteristics of a processed pseudogene. In clone lambda hg29 (CaMII-psi 3), however, an Alu repetitive sequence was detected immediately upstream from the ancestral 5'-untranslated region. Downstream from the truncated 3'-untranslated region, three additional copies of Alu repetitive sequences flanking about 750 nucleotides of unknown origin were found. Such a processed retropseudogene flanked by multiple Alu repeats may be a target for further recombination events. The three retropseudogenes CaMII-psi 1, CaMII-psi 2 and CaMII-psi 3 are estimated to be about 49, 21 and 25 million years old, respectively.

Animals↗
PubMed1991

Concentrations and patterns of released pterins of various animal cell cultures.

Neopterin, biopterin, pterin, 6-hydroxymethylpterin and isoxanthopterin were determined in the supernatants of various animal cell cultures. The different cell lines showed distinct variations in the concentrations as well as in the pattern and total amount of the released pterins. In cells from the same organ but from diverse species differences in pattern and release were found. Cell lines derived from primates had a high release of neopterin. A further difference resulted from the origin of fetal or adult organs. Neoplastic cell lines showed different patterns of pterins, dependent on the type of tumour. Primary cultures from embryonic bovine lung had the highest total amount of released pterins in all cell lines examined.

Animals↗
PubMed1991

A survey of cattle for antibodies against bluetongue and epizootic hemorrhagic disease of deer viruses in British Columbia and southwestern Alberta in 1987.

In 1987 a serological survey of cattle for antibodies (Ab) to bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) was undertaken in British Columbia and southwestern Alberta after infection with the viruses was diagnosed in wild and domestic ruminants in the Okanagan Valley. Of 4610 cattle tested, five had Ab only to BTV, 125 had antibodies only to EHDV and 16 had Ab to both viruses. The Ab were identified as specific for BTV type 11 (BT-11) or EHDV type 2 (EHDV-2). All but one of the seropositive cattle originated in the Okanagan Valley of British Columbia. The remaining one seropositive animal which had Ab to EHDV-2 was pastured with a bull purchased from the Okanagan Valley.

Alberta↗
PubMed1990

Structural organization of the human CaMIII calmodulin gene.

The complete structural organization of the human calmodulin III gene has been determined. This gene specifies the mRNA represented by the previously reported cDNA ht6. The gene contains six exons spread over a total of approx. 10 kb of DNA. Its exon-intron organization is identical to that of the only known chicken calmodulin gene and to that of two of the three characterized rat calmodulin genes. As in many other genes encoding Ca2+ binding proteins, intron 1 separates the ATG initiation codon from the remainder of the coding region. The major and two minor sites of transcription initiation have been determined by primer extension and ribonuclease protection assays. The DNA sequence in the promoter and 5' untranslated region is extremely GC-rich. No typical TATA and CAAT boxes are present upstream of the major transcriptional start site; however, a consensus CAAT box sequence is found further upstream and may play a role in transcriptional initiation from the minor start sites. Six sequence elements with high similarity to monkey SV40-like Sp1-binding regions are present in the putative promoter region, two of which contain perfect GGGCGG core sequences. The structure of the human calmodulin III gene promoter indicates that this gene belongs to a class of 'house-keeping' genes but that its level of expression may also be specifically regulated.

Amino Acid Sequence↗
PubMed1990

The influence of nutritional factors on biopterin excretion in laboratory animals.

Nutritional influences on urinary total biopterin levels in rats and pigs were investigated. During the first nights in metabolic cages with food deprivation a significant increase in biopterin values was found in rats. This could be diminished either by feeding, adaptation to food deprivation or by oral glucose application. With food deprivation under normal housing conditions, this increase could not be found. Rats that were fed a cellulose preparation without metabolizable energy had no increase in biopterin excretion. The circadian rhythm of biopterin excretion was influenced by food deprivation as well as by cellulose. Alterations in water intake and urinary output had no effect on biopterin levels related to creatinine. Remarkable changes in biopterin excretion are more likely due to hormonal functions and regulations related to stress than to nutritional factors. More investigations into these problems are being performed.

Animal Nutritional Physiological Phenomena↗
PubMed1990

Adjusted hypervolemic hemodilution in acute ischemic stroke.

We prospectively randomized 47 patients with acute ischemic stroke of the middle cerebral artery of less than 24 hours' duration to either adjusted hypervolemic hemodilution or control treatment and followed them up for 90 days. Rapid hemodilution to a target hematocrit of 30-35% as monitored with bedside determinations was achieved by using infusions of dextran 40, venesections, and infusions of additional crystalloid solution when necessary. There was no difference in the death rate between the two treatment groups. Of these 47 patients, 37 (19 in the hemodilution group and 18 in the control group) could be followed up for the entire study period of 3 months. The relative improvement in neurologic function from day 1 to days 8, 21, and 90 was significantly better in the hemodilution group than in the control group. In accordance, special tests for fine motor control of the paretic arm disclosed better performance in the hemodilution group. The frequency of patients with severe disability was significantly lower in the hemodilution group on days 8 and 21. Plasma viscosity (measured in 11 patients) was not affected by infusions of dextran 40. Vigorous hypervolemic hemodilution in patients with acute ischemic stroke is well tolerated and improves early neurologic outcome with an effect lasting at least 3 months.

Aged↗
PubMed1990

Early relapses of varicella-zoster virus infection in immunocompromised children treated with acyclovir.

Authors observed one or more early VZV relapses in 8 out of 98 Acyclovir treated immunocompromised children with varicella. None of the 8 children developed VZV antibodies by the end of the 5-day ACV treatment. All VZV relapses were successfully treated with ACV or Vidarabine, but were stopped only after the appearance of VZV antibodies in the patients' sera. The possible role of ACV treatment in pathogenesis of early VZV relapses could be excluded by comparing the VZV antibody production of patients treated with ACV from the first day of varicella on with the antibody response of those, who received ACV as late as on the 5th day of varicella. By prolonging the ACV treatment till the appearance of VZV antibodies, early relapses could be avoided.

Acyclovir↗
PubMed1988

[Fibrinolysis in acute myocardial infarct. Treatment rate, assessment and follow-up treatment in the Zürich hospitals].

We report the results of i.v. fibrinolysis in patients with acute myocardial infarction treated in four major hospitals in Zürich. Between 1986 and 1988 only 96 (9%) of 1069 patients admitted to intensive care units with acute myocardial infarction received thrombolytic therapy (less than 3 hours after onset of symptoms), 7% (50/703) during the first treatment period (streptokinase for 14 months), 13% (46/306) during the second treatment period (rt-PA for 8 months). The hospital mortality was 4% and severe complications of fibrinolytic therapy occurred in 4%. Coronary angiography was performed in 60% of patients in 1986/87 and in 87% in 1987/88. Despite this significant increase in invasive diagnostic procedures the percentage of patients after thrombolysis qualifying for invasive therapy remained unchanged at 53%. The indications for PTCA or bypass surgery were postinfarct angina in 41%, silent ischemia in 5%, left main coronary artery stenosis or multivessel disease with reduced left ventricular ejection fraction in 16%, and residual high grade stenosis with preserved contractility of the infarct-related myocardium in 38%. The mean in-hospital stay was 16 days, with significant variation from 13 to 22 days between the different hospitals (p less than 0.05). In the follow-up of 65 men aged below 65 years, 75% of the patients undergoing invasive therapy and 65% of those treated medically had returned to work 6 months after myocardial infarction. Due to the limited possibility of detecting viable myocardium by non-invasive methods, and the high rate of invasive therapy necessary in our patients, further management after thrombolysis should generally include large scale coronary angiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticoagulants↗
PubMed1988

Multiple divergent mRNAs code for a single human calmodulin.

The isolation of a novel complementary DNA (cDNA) clone coding for human calmodulin (CaM) is reported. Although it encodes a protein indistinguishable from the only known higher vertebrate calmodulin, its nucleotide sequence varies extensively from that of two previously reported human CaM cDNAs (Wawrzynczak and Perham, 1984; SenGupta et al., 1987). Only 82 and 81% identity, respectively, is found between the newly isolated and the two known human mRNAs in their coding regions. No striking homology is present in their noncoding regions. Codon usage in the three CaM mRNAs is also surprisingly divergent. A 2.3-kilobase mRNA corresponding to the newly isolated clone is expressed to varying extents in several human tissues, together with an approximately 0.8-kilobase mRNA species presumably arising from alternative polyadenylation of the same primary transcript. The results indicate that the human genome contains at least three divergent CaM genes that are under selective pressure to encode an identical protein while maintaining maximally divergent nucleotide sequences. Partial characterization of a genomic clone specifying the 3' portion of the newly identified CaM mRNA shows that this gene contains introns at identical positions as the previously characterized bona fide vertebrate CaM genes. Evolutionary implications of the presence of a CaM multigene family are discussed.

Amino Acid Sequence↗
PubMed1988

Characterization of an intronless human calmodulin-like pseudogene.

We report the isolation and characterization of a human genomic clone encoding a calmodulin-like pseudogene. It contains an open reading frame of 444 nucleotides, not interrupted by introns. The nucleotide sequence of the open reading frame shows 80%, 71% and 69% identity to the previously reported human calmodulin cDNAs lambda ht6 [17], hCWP [22], and lambda hCE1 [23], respectively. The derived amino acid sequence has only 85% identity to vertebrate calmodulin, but shows four potentially functional Ca2+-binding loops. In the human tissues tested, this pseudogene is not expressed, though gene structure including promoter elements and a putative polyadenylation site seems to be intact.

Amino Acid Sequence↗
PubMed1988

[Fasciola hepatica infection. Successful therapy using triclabendazole].

We report a case of human fascioliasis treated successfully with a single dose of triclabendazole, a benzimidazole compound. The most obvious effect was the rapid cessation of faecal egg excretion, which had been refractory to two previous treatment courses of albendazole. Cure seems to be confirmed by the absence of Fasciola eggs in repeated stool examinations after six months, achievement of clinical wellbeing, and normalization of laboratory tests. The only side effect of the treatment was a brief episode of fever and right upper abdominal pain occurring four days after administration of triclabendazole. The syndrome was probably due to disintegrating dead parasites; further observations are needed to explain the pathogenesis of this episode.

Animals↗
PubMed1988

Iatrogenic mechanical ileus due to over-distended uterus.

The combination of an over-distended uterus caused by a multiple-fetus pregnancy with therapeutic bed-rest may cause mechanical ileus. Iatrogenic triggering of a pathological consequence of events is presented in purpose to highlight the simplicity of its prevention.

Adult↗
PubMed1988

Results for 74 substances tested for interference with determination of plasma catecholamines by "high-performance" liquid chromatography with electrochemical detection.

Various catecholamine metabolites, catecholamine-related compounds, catechols, drugs, amines, and other nitrogen compounds were injected onto an HPLC system ("ClinRep Catecholamine-Plasma" assay kit with a reversed-phase C18 column) used for measuring catecholamines. None of the 74 substances tested co-eluted with any of the catecholamines--norepinephrine, epinephrine, or dopamine--or with the internal standard, 3,4-dihydroxybenzylamine.

Catecholamines↗