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J Straub

Publications and source records attributed to J Straub.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Diagnosis of systemic mycotic infections].

The diagnosis of mycotic infections still remains a serious problem. The clinical picture lacks specific manifestations, usually it does not differ substantially from bacterial infections. Routine laboratory examinations are only of subsidiary importance and even more specific methods (assessment of antibodies, and in particular detection of mycotic antigens) do not meet expectations so far. To establish the diagnosis of systemic mycosis it is thus most important to consider the possibility and to support clinical suspicion by an aimed examination.

Humans↗
PubMed1993

[The most common pathogens in opportunistic mycoses and their clinical manifestations].

The most frequent pathogens of opportunistic mycotic infections are Candidae. The clinical manifestation of infection is very varied. With regard to the extent of the affection the following are differentiated: 1. mucocutaneous candidosis, 2. organ affections and 3. disseminated candidosis. The incidence of mycoses caused by Aspergillae, cryptococci, and mucors is of a lower order, these infections are, however, associated with a relatively higher mortality. The authors review briefly different fungi and describe the most important clinical manifestations of infection.

Humans↗
PubMed1991

Renal function and metabolism during endotoxemia in rats: role of hypoperfusion.

Renal failure often complicates endotoxin shock. This might be due to renal hypoperfusion, but endotoxemia could also have additional effects. We studied in anesthetized rats renal plasma flow (RPF), glomerular filtration rate (GFR), and metabolism (ATP, CrP = creatine phosphate, energy charge = [ATP + 0.5 ADP]/[ATP + ADP + AMP], lactate, glucose) during endotoxin shock (Escherichia coli endotoxin, 10 mg/kg for 60 min; n = 10) and "balloon shock" (balloon inflated in vena cava below renal vein to cause comparable decreases in cardiac output and RPF as in endotoxin-treated rats; n = 10). A third group of rats served as controls (n = 10). At t = 0 infusion of endotoxin was started. At t = 90 min, when cardiac output was low and serum lactate was high (indicating shock), GFR and RPF were obtained from plasma disappearance rates (from t = 90 to t = 135 min) of 125I-thalamate and 131I-hippurate, respectively. Experiments ended at t = 135 min. In both shock groups RPF decreased (by ca. - 75% compared with control rats), but filtration fraction only increased (by 72%) in the "balloon shock" rats. In renal biopsies lactate concentration increased more (by 407 vs. 167%) and ATP decreased more (by -63 vs. - 35%) during endotoxin shock than during "balloon shock"; the endotoxin-treated rats also showed a significant decrease in CrP (by - 58%), energy charge (by - 31%), and glucose concentration (by - 34%), and an increase in the number of leukocytes in the glomeruli (by 730%). Renal function and metabolism thus was more affected in this hypodynamic form of endotoxin shock than in "balloon shock." This may be caused by the effects of endotoxin on sticking of leukocytes and renal metabolism.

Adenosine Diphosphate↗
PubMed1990

Effects of N-acetylcysteine and terbutaline treatment on hemodynamics and regional albumin extravasation in porcine septic shock.

We studied the therapeutic effects of continuously infused N-acetylcysteine, an O2 radical scavenger (N, n = 6), and terbutaline, a beta 2-agonist (T, n = 6), versus dextrose (controls C, N = 6) on hemodynamics and regional albumin extravasation in porcine septic shock. After instrumentation, injection of 99mTc-labeled red blood cells, and baseline measurements, pigs received a 90 min infusion of 11 +/- 9 X 10(8).kg-1 live Escherichia coli bacteria. Thereafter, therapy was started, and 131I human serum albumin was injected. Images were obtained hourly using a gammacamera and a computer until 5 hours after baseline. Regions of interest were drawn in the 99mTc images, yielding regional 131I/99mTc radioactivity ratios, with blood samples as reference. From these ratios, an albumin leak index, a rate constant of transvascular albumin transport, was calculated. Control pigs developed pulmonary hypertension, arterial hypotension, hemoconcentration, and lactic acidemia. In spite of tachycardia and unchanged filling pressures, cardiac output fell. In arterial blood, white cell count, PO2, albumin level, and colloid osmotic pressure fell. The albumin leak index (X10(-3).min-1) measured 1.56 +/- 0.59 over the lungs and 2.87 +/- 1.19 over the abdomen in C (P less than .05 vs. lung), confirming previously found increased albumin flux in both lung and abdomen, the latter exceeding the former. Neither N nor T significantly affected hemodynamic and biochemical changes. The drugs neither decreased the regional albumin leak index nor attenuated the formation of albumin-rich ascites found at autopsy. However, the lung albumin index obtained at autopsy was significantly reduced with N (P less than .01 vs. C), at similar gravimetrically determined extravascular lung water (EVLW). EVLW positively correlated with pulmonary albumin extravasation in C (rs = 0.94, P less than .05) and T (rs = 0.89, P = .05) but not in N (rs = -0.37, n.s.). We conclude that neither N nor T treatment beneficially influences the course of septic shock in pigs. Although neither drug combats noninvasively assessed regional microvascular albumin leakage and formation of albumin-rich ascites, N may ameliorate increased pulmonary microvascular permeability as judged from post mortem data.

Animals↗
PubMed1989

Bacteriorhodopsin mutants of Halobacterium sp. GRB. II. Characterization of mutants.

The bacterioopsin genes of Halobacterium sp. GRB (Ebert, K., Goebel, W., and Pfeifer, F. (1984) Mol. & Gen. Genet. 194, 91-97) wild type and 10 independent mutants of different phenotypes have been cloned and sequenced. The wild type gene has two conservative changes compared to the gene of Halobacterium halobium, so that the proteins of the two species are identical. Six different mutations at five different codons have been found, leading to the following amino acid changes compared to the wild type: Trp10----Cys (three cases), Tyr57----Asn, Asp85----Glu, Asp06----Asn (three cases), Asp96----Gly, Trp138----Arg. A first characterization of the mutant proteins is given, and their implications for models of bacteriorhodopsin structure and function are discussed.

Amino Acid Sequence↗
PubMed1989

[The role of beta-endorphins in silent forms of ischemic heart disease].

Silent--asymptomatic--ischaemia is one of the forms of ischaemic heart disease. Present possibilities of non-invasive diagnostics are based primarily on long-term ECG monitoring. With regards to the hypothesis that the raised algesic threshold at high level of analgetically reacting beta endorphins seems to be the pathophysiologic basis of this particular syndrome, we tried to verify the presumption by administering a beta-endorphin antagonist-naloxon. In 13 patients with a silent form of ischaemic heart disease (absence of stenocardia in objectively proved ischaemia in loading test) we made the loading test in a standard form and after administering of 2 mgs of naloxan intravenously. Owing to the fact that stenocardia developed only in one patient after endogenous opiate effect blockage we presume that pathophysiologic basis of this syndrome must be discovered elsewhere.

Coronary Disease↗
PubMed1982

Reversible inhibition of the proton pump bacteriorhodopsin by modification of tyrosine 64.

Five mol of lysine per mol of bacteriorhodopsin were modified with methylacetimidate. This treatment did not inactivate bacteriorhodopsin but prevented all lysines from subsequent reaction with diazotized sulfanilic acid. This reaction predominantly modified tyrosine 64 and light-induced proton translocation was abolished. Reduction of the mono(p-azobenzene sulfonic acid) tyrosine 64 to the corresponding 3-amino derivative with sodium dithionite led to complete reactivation of the proton translocation activity of bacteriorhodopsin. The relative location of tyrosines 26 and 64 and the COOH terminus on the two surfaces of the purple membrane was determined by incorporation into phospholipid vesicles, subsequent modification, and proteolytic treatment. The results obtained support the models proposed by Engelmann et al. (Engelman, D. M., Henderson, R. McLauchlan, A. D., and Wallace, B. A. (1980) Proc. Natl. Acad. Sci. U. S. A. 77, 2023-2027) and by Ovchinnikov et al. (Ovchinnikov, Yu. A., Abdulaev, N. G., Feigina M. Yu., Kiselev A. V., and Lobanov, N. A. (1979) FEBS Lett. 100, 219-224). Tyrosine 64 is located on the extracellular side of the membrane, whereas tyrosine 26 and the COOH terminus are located on the cytoplasmic side. Because specific nitration of tyrosine 26 also leads to inactivation of bacteriorhodopsin (Lemke, H. D., and Oesterhelt, D. (1981) Eur. J. Biochem. 115, 595-604), the results obtained demonstrate that amino acid residues located on both surfaces of the purple membrane are involved in proton translocation.

Amino Acid Sequence↗
PubMed1981

Mendelian transmission of genes introduced into plants by the Ti plasmids of Agrobacterium tumefaciens.

Insertion of the bacterial transposon Tn7 was used to obtain mutants of an octopine Ti plasmid. Crown gall tumours induced on tobacco by an Agrobacterium tumefaciens strain carrying a particular mutant Ti plasmid (pGV2100) were found to give rise to shoots. These shoots were grown in vitro and one of them (rGV-1) was found to contain the T-DNA specific enzyme lysopine dehydrogenase (LpDH) and to form roots. After transfer to soil, rGV-1 developed into a morphologically and functionally normal tobacco plant. All cells of the regenerant and of vegetatively produced offspring were shown, by cloning of leaf protoplasts, to contain T-DNA and LpDH activity, rGV-1 and vegetatively produced offspring flowered normally. Plantlets obtained from haploid anther cultures were tested for LpDH activity. Forty-one percent of these plantlets were LpDH positive. Moreover, both self-pollination of rGV-1 and crosses between rGV-1 and normal tobacco plants showed that the LpDH character was transmitted both through the pollen and through the eggs of rGV-1 as a single dominant factor with Mendelian segregation ratios typical for monohybrid crosses. By repeated selfing, homozygous plants were obtained which bred true with respect to LpDH. The importance of these findings with respect to the use of Agrobacterium tumefaciens and Ti plasmids for genetic engineering in plants is discussed.

Crosses, Genetic↗
PubMed1979

Identity of malonyl and palmitoyl transferase of fatty acid synthetase from yeast. Functional interrelationships between the acyl transferases.

Functional interrelationships between the acyl transferases of yeast fatty acid synthetase were investigated. In binding assays with synthetase modified by 5,5'-dithiobis(2-nitrobenzoic acid), 4--5 malonyl transferase entities per multienzyme complex molecule could be titrated. In the presence of palmitoyl-CoA these malonyl transferases were found inaccessible to malonyl-CoA, whereas the acetyl transferases were reactive towards acetyl-CoA. Between four and five palmitoyl transferase entities per synthetase equivalent were found reactive towards palmitoyl-CoA, the palmitoyl binding being inhibited by malonyl-CoA. Following palmitoyl binding the acetyl transferases were found towards acetyl-CoA. Substrate model assays were consistent with these data. It is concluded that malonyl and palmitoyl transferases are closely coupled enzyme components of the multienzyme complex which are fairly independent of the acetyl transferase entities. The molecular basis for the observed coupling will be given in the following paper.

Acyltransferases↗
PubMed1979

Identity of malonyl and palmitoyl transferase of fatty acid synthetase from yeast. 2. A comparison of active-site peptides.

Active-site peptides of malonyl and palmitoyl transferase from yeast fatty acid synthetase were isolated and sequenced to try to prove the hypothesis [J. Ayling, R. Pirson & F. Lynen (1979) Biochemistry 11, 526--533] that both enzymes are identical. For this purpose synthetase modified with 5,5'-dithiobis(2-nitrobenzoic acid) was labelled with either [14C]malonyl or [14C]palmitoyl residues followed by proteolytic digestion of the labelled protein. [14C]Malonyl-peptides were isolated by conventional purification procedures; their structures were determined by a combination of methods. [14C]Palmitoyl-peptide material was purified by high-performance liquid chromatography and the structure determined by solid-phase Edman degradation and other analytical methods. Serine was identified as the acyl acceptor group in both transferases. Comparison of the sequence data available shows that the sequence around the acyl acceptor group in both cases is identical. This proves the identity of malonyl and palmitoyl transferase.

Acyltransferases↗
PubMed1977

Genetic characterization and high efficiency photosynthesis of an aurea mutant of tobacco.

A new tobacco (Nicotiana tabacum) aurea mutant was isolated from the progeny of a selfed variegated tobacco plant. The new mutant is termed Su/su var. Aurea. If the mutant is selfed, the seeds obtained give rise to four types of plants: green seedlings which correspond to the wild type; yellow-green seedlings which correspond to the earlier described Su/su; yellow seedlings which correspond to the new tobacco aurea mutant Su/su var. Aurea; and white lethal seedlings. The frequency ratio of the four phenotypes is 1:1:1:1. It appears that the mutation is due to two independent nuclear factors, su and aur, both of which have to be present in a heterozygous conditions, Su/su Aur/aur, to give rise to the new aurea phenotype. The aurea mutant Su/su var. Aurea has a reduced photosynthetic unit size which is approximately one-eighth of the wild type. Despite its chlorophyll deficiency, the plant grows well and exhibits maximal photosynthetic rates on a chlorophyll basis which are at least seven times higher than those of the green wild type provided the temperature and the light intensities are high enough. In contrast to the earlier described Su/su, the new mutant does not exhibit more photorespiration than the wild type. It appears that the factor aur causes either repression of photorespiration or an increase in the number of functioning photosynthetic units.

Journal Article↗