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S Albert

Publications and source records attributed to S Albert.

At least 37 records · Page 2Linked to original sources
PubMed2001

Multivariate statistical monitoring of batch processes: an industrial case study of fermentation supervision.

This article describes the development of Multivariate Statistical Process Control (MSPC) procedures for monitoring batch processes and demonstrates its application with respect to industrial tylosin biosynthesis. Currently, the main fermentation phase is monitored using univariate statistical process control principles implemented within the G2 real-time expert system package. This development addresses integrating various process stages into a monitoring system and observing interactions among individual variables through the use of multivariate projection methods. The benefits of this approach will be discussed from an industrial perspective.

Fermentation↗
PubMed2000

Crystal structure of the GAP domain of Gyp1p: first insights into interaction with Ypt/Rab proteins.

We present the 1.9 A resolution crystal structure of the catalytic domain of Gyp1p, a specific GTPase activating protein (GAP) for Ypt proteins, the yeast homologues of Rab proteins, which are involved in vesicular transport. Gyp1p is a member of a large family of eukaryotic proteins with shared sequence motifs. Previously, no structural information was available for any member of this class of proteins. The GAP domain of Gyp1p was found to be fully alpha-helical. However, the observed fold does not superimpose with other alpha-helical GAPs (e.g. Ras- and Cdc42/Rho-GAP). The conserved and catalytically crucial arginine residue, identified by mutational analysis, is in a comparable position to the arginine finger in the Ras- and Cdc42-GAPs, suggesting that Gyp1p utilizes an arginine finger in the GAP reaction, in analogy to Ras- and Cdc42-GAPs. A model for the interaction between Gyp1p and the Ypt protein satisfying biochemical data is given.

Amino Acid Motifs↗
PubMed2000

Millimeter-Wave Spectra and Global Torsion-Rotation Analysis for the CH(3)OD Isotopomer of Methanol.

New millimeter-wave and microwave measurements for CH(3)OD have been combined with previous literature data and with an extended body of Fourier transform far-infrared observations in a full global analysis of the first two torsional states (v(t) = 0 and 1) of the ground vibrational state. The fitted CH(3)OD data set contained 564 microwave and millimeter-wave lines and 4664 far-infrared lines, representing the most recent available information in the quantum number ranges J </= 20 and K </= 15. A 53-parameter converged global fit was achieved with an overall weighted standard deviation of 1.060, essentially to within the assigned measurement uncertainties of +/-100 kHz for almost all of the microwave and millimeter-wave lines and +/-6 MHz for the far-infrared lines. The new parameters for CH(3)OD are compared to previous results obtained for the (12)CH(3)OH, (13)CH(3)OH, and CD(3)OH isotopomers over the same quantum number ranges using the identical fitting program. Strong asymmetry-induced coupling between the accidentally near-degenerate 0E and -1E v(t) = 0 substates is successfully modeled by the fit. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

[Epidemiology and therapy of bacterial infections in geriatrics].

As the elderly segment of our population expands, there is an increase of therapeutic problems considering this age group. The elderly patient is generally susceptible to infections because of the decline in host defense mechanisms that occurs with aging, and the underlying chronic diseases of these patients. Increasing numbers of elderly people are being treated in hospitals and are additionally at particular risk of acquiring nosocomial infections with antibiotic-resistant organisms. This article focuses on the epidemiological considerations, risk factors, types of infections that occur in elderly patients, and the guidelines for empiric therapy. The most common infections of the elderly are respiratory tract infection, urinary tract infection, and skin and soft tissue infection. Empirical therapy should be broader in spectrum for elderly patients since the variety of infecting bacteria tends to be greater and the choice of antimicrobial therapy must be based on risk stratification (age, medical illnesses, and severity of presentation). Many additional aspects, e.g., route of administration, drug pharmacokinetics and pharmacodynamics, drug toxicity and drug-drug interactions, compliance, and multiple underlying diseases (e.g., renal failure) must be considered in the rational selection of antibiotic regimen.

Aged↗
PubMed2000

[Significance of methicillin resistant S. aureus (MRSA) in geriatrics--epidemiology, therapy and management].

Methicillin-resistant S. aureus (MRSA) has become an important cause of severe infection in hospitalized patients all over the world. In Germany a significant increase of nosocomial infections due to MRSA has occurred during the last 10 years. Especially elderly patients with chronic illnesses are at increased risk of becoming colonized or infected with MRSA. This report focuses on epidemiology and therapy of MRSA, and on the recommendations concerning management and prevention of spread of MRSA in hospitals and nursing homes.

Aged↗
PubMed2000

Early percutaneous tracheostomy after median sternotomy.

OBJECTIVE: Tracheostomy offers significant advantages over endotracheal intubation in patients requiring long-term assisted ventilation. However, in patients who have undergone median sternotomy, it is believed that the danger of microbial contamination and consecutive infection of the sternal wound with microbes from the tracheostomy is high when conventional tracheostomy is performed. In contrast, percutaneous techniques are less likely to result in tracheostomy infection and thus bacterial contamination of neighboring structures. Nonetheless, to date there has been no prospective study confirming or disproving this assumption. Our study evaluated outcome after percutaneous tracheostomy in patients with a median sternotomy. METHODS: A total of 144 cardiac surgical patients had elective percutaneous tracheostomy at the bedside until postoperative day 14, with 4 different techniques. Systematic microbiologic monitoring of the sternal and tracheal wounds was used. RESULTS: In 13 patients sternal wound infection was suspected, but was confirmed in only 4 (2.8%) patients who actually showed microbial contamination of the sternum. In 2 of these patients, the identified microbes were not identical to those cultured from the trachea. The other 2 patients had sternal and tracheal cultures positive for methicillin-resistant Staphylococcus aureus. Cross-contamination of the sternotomy with microbes from the patient's airways was therefore ruled out. No patient had clinical signs of tracheostomy infection. Likewise, there were no cases of mediastinitis. CONCLUSIONS: On the basis of our data, we conclude that cross-contamination of the sternal wound with microbes from the trachea is not a problem. Elective percutaneous tracheostomy is safe, even if performed during the first 14 days after median sternotomy.

Analysis of Variance↗
PubMed2000

Direct action of the nodal-related signal cyclops in induction of sonic hedgehog in the ventral midline of the CNS.

The secreted molecule Sonic hedgehog (Shh) is crucial for floor plate and ventral brain development in amniote embryos. In zebrafish, mutations in cyclops (cyc), a gene that encodes a distinct signal related to the TGF(beta) family member Nodal, result in neural tube defects similar to those of shh null mice. cyc mutant embryos display cyclopia and lack floor plate and ventral brain regions, suggesting a role for Cyc in specification of these structures. cyc mutants express shh in the notochord but lack expression of shh in the ventral brain. Here we show that Cyc signalling can act directly on shh expression in neural tissue. Modulation of the Cyc signalling pathway by constitutive activation or inhibition of Smad2 leads to altered shh expression in zebrafish embryos. Ectopic activation of the shh promoter occurs in response to expression of Cyc signal transducers in the chick neural tube. Furthermore an enhancer of the shh gene, which controls ventral neural tube expression, is responsive to Cyc signal transducers. Our data imply that the Nodal related signal Cyc induces shh expression in the ventral neural tube. Based on the differential responsiveness of shh and other neural tube specific genes to Hedgehog and Cyc signalling, a two-step model for the establishment of the ventral midline of the CNS is proposed.

Animals↗
PubMed2000

Effect of solvent residues of Vitex negundo Linn. and Cassia fistula Linn. on pulse beetle, Callosobruchus maculatus Fab. and its larval parasitoid, Dinarmus vagabundus (Timberlake).

Effect of solvent residues of Vitex negundo L. and Cassia fistula L. leaves (0.5 and 1%) was studied on egg laying and adult emergence of Callosobruchus maculatus Fab. and on percentage of larval parasitism by Dinarmus vagabundus (Timberlake). Cowpea seeds treated with methanol and aqueous extract of Vitex, at these concentrations (0.5 and 1%), significantly reduced the number of eggs and emergence of F1 adults of C. maculatus. Both Vitex and Cassia extracts did not affect the percentage of parasitism by D. vagabundus on C. maculatus grubs.

Animals↗
PubMed1999

Rate of memory decline in AD is related to education and occupation: cognitive reserve?

OBJECTIVE: To determine whether the rate of decline in performance on a memory test is more rapid in AD patients with higher versus lower educational and occupational attainment. BACKGROUND: Epidemiologic and imaging studies have suggested that, given comparable clinical severity of dementia, AD pathology is more advanced in patients with higher educational and occupational attainment. Because educational and occupational attainment should not influence the progression of AD pathology, and because severe AD pathology will eventually produce a mortality-causing condition, people with higher attainment might experience clinical AD for a shorter time and have a more rapid clinical progression. METHODS: A total of 177 AD patients were tested yearly for up to four study visits with the Selective Reminding Test (a memory test). Analysis of prospective change in the total recall score was performed by applying generalized estimating equations to regression analyses with repeated measures. RESULTS: At the initial visit, scores were comparable in the high- and low-education and the high- and low-occupation groups. Overall, memory scores declined by approximately 1 point yearly (p<0.01). There was a more rapid decline in memory scores in patients with higher educational (p<0.057) and higher occupational attainment (p<0.02). The authors then stratified patients based on their initial memory scores. The more rapid decline in memory scores associated with higher educational and occupational attainment was noted only in the group with low initial scores (p<0.05 for both). The full group and stratified group analyses were also repeated controlling for other potentially relevant variables including age, gender, race, ethnicity, and the presence of extrapyramidal signs, stroke, or at least one apolipoprotein E-epsilon4 allele. The results remained unchanged. CONCLUSIONS: Memory declined more rapidly in AD patients with higher educational and occupational attainment. This adds support to the idea that the discontinuity between the degree of AD pathology and the observed clinical severity of AD is mediated through some form of reserve.

Aged↗
PubMed1999

Two new members of a family of Ypt/Rab GTPase activating proteins. Promiscuity of substrate recognition.

Monomeric GTPases of the Ras superfamily have a very slow intrinsic GTPase activity which is accelerated by specific GTPase-activating proteins. In contrast to Ras- and Rho-specific GTPase-activating proteins (GAPs) that have been studied in great detail, little is known about the functioning of GAPs specific for Ypt/Rab transport GTPases. We have identified two novel Ypt/Rab-GAPs because of their sequence relatedness to the three known GAPs Gyp1p, Gyp6p, and Gyp7p. Mdr1/Gyp2p is an efficient GAP for Ypt6p and Sec4p, whereas Msb3/Gyp3p is a potent GAP for Sec4p, Ypt6p, Ypt51p, Ypt31/Ypt32p, and Ypt1p. Although the affinity of Msb3/Gyp3p for its preferred substrate Sec4p is low (K(m) = 154 microM), it accelerates the intrinsic GTPase activity of Sec4p 5 x 10(5)-fold. Msb3/Gyp3p appears to be functionally linked to Cdc42p-regulated pathway(s). The results demonstrate that in yeast there is a large family of Ypt/Rab-GAPs, members of which discriminate poorly between GTPases involved in regulating different steps of exo- and endocytic transport routes.

Amino Acid Sequence↗
PubMed1999

Identification of the catalytic domains and their functionally critical arginine residues of two yeast GTPase-activating proteins specific for Ypt/Rab transport GTPases.

Ypt/Rab proteins constitute the largest subfamily of the Ras superfamily of monomeric GTPases and are regulators of vesicular protein transport. Their slow intrinsic GTPase activity (10(-4)-10(-3) min(-1) at 30 degrees C) has to be accelerated to switch the active to the inactive conformation. We have identified the catalytic domain within the C-terminal halves of two yeast GTPase-activating proteins (GAPs), Gyp1p and Gyp7p, with specificity for Ypt/Rab GTPases. The catalytically active fragments of Gyp1p and Gyp7p were more active than the full-length proteins and accelerated the intrinsic GTP hydrolysis rates of their preferred substrates by factors of 4.5 x 10(4) and 7.8 x 10(5), respectively. The K(m) values for the Gyp1p and Gyp7p active fragments (143 and 42 microM, respectively) indicate that the affinities of those GAPs for their substrates are very low. The catalytic domains of Gyp1p and Gyp7p contain five invariant arginine residues; substitutions of only one of them (R343 in Gyp1p and R458 in the analogous position of Gyp7p) rendered the GAPs almost completely inactive. We suggest that Ypt/Rab-GAPs, like Ras- and Rho-GAPs, follow the same mode of action and provide a catalytic arginine ('arginine finger') in trans to accelerate the GTP hydrolysis rate of the transport GTPases.

Amino Acid Sequence↗
PubMed1999

The influence of smoking on the risk of Alzheimer's disease.

OBJECTIVE: To investigate the relationship between cigarette smoking and Alzheimer's disease (AD) in a prospective community-based study in northern Manhattan. BACKGROUND: Results from previous case-control studies suggest that there is a protective effect of smoking on AD. However, the recent prospective Rotterdam Study found that there was an increased risk of AD for smokers, particularly those without an apolipoprotein E (APOE)-epsilon4 allele. METHODS: The authors examined data from a community-based longitudinal study of local elders residing in northern Manhattan to determine whether tobacco use increases or decreases the risk of AD. Information regarding the frequency of tobacco use was obtained in structured interviews at the baseline assessment. Standardized clinical assessments were subsequently completed on each subject at annual visits during which incident cases of AD were identified. RESULTS: The relative risk (RR) of AD among former smokers was 0.7 (95% CI, 0.5 to 1.1). The RR among current smokers was 1.9 (95% CI, 1.2 to 3.0). Smokers without an APOE-epsilon 4 allele had the highest risk of AD (RR = 2.1; 95% CI, 2.1 to 3.7) compared with those with an APOE-epsilon 4 allele (RR = 1.4; 95% CI, 0.6 to 3.3). CONCLUSIONS: Our results are consistent with the observation that smoking increases the risk of AD. However, we found that among previous smokers who quit smoking, there may be a slight reduction in the risk of AD.

Aged↗
PubMed1999

The family of major royal jelly proteins and its evolution.

A cDNA encoding a new member of the gene family of major royal jelly proteins (MRJPs) from the honeybee, Apis mellifera, was isolated and sequenced. Royal jelly (RJ) is a secretion of the cephalic glands of nurse bees. The origin and biological function of the protein component (12.5%, w/w) of RJ is unknown. We show that the MRJP gene family encodes a group of closely related proteins that share a common evolutionary origin with the yellow protein of Drosophila melanogaster. Yellow protein functions in cuticle pigmentation in D. melanogaster. The MRJPs appear to have evolved a novel nutritional function in the honeybee.

Amino Acid Sequence↗
PubMed1999

Lyme arthritis in a 12-year-old patient after a latency period of 5 years.

Lyme arthritis (LA) may be confused with other rheumatic diseases, particularly in the absence of a history of erythema migrans (EM). We report the case of a 12-year-old patient who developed a large effusion of the right knee joint. The titer for antinuclear antibodies was 1:80 and the test for rheumatoid factor was negative. Investigations for antibody response to Borrelia burgdorferi demonstrated remarkable elevation of IgG antibody and no specific IgM response. These results were confirmed by immunoblotting reactivity with the bands p83/100, p58, p43, p41, p39, OspA, p30, OspC, p21, and p17. We subsequently learned that the child had suffered a tick bite followed by an EM 5 years earlier and had been treated with trimethoprim/sulfamethoxazole at that time. The patient now was given intravenous ceftriaxone, 2 g daily for 14 days. In the absence of clinical improvement 3 weeks later a knee joint aspiration was performed which resulted in a positive polymerase chain reaction (PCR) test for B. burgdorferi DNA (OspA) in the synovial fluid. The patient fully recovered 2 months later without further treatment. The case indicates that the latency period between EM and onset of LA may last up to 5 years. In addition to serologic test methods, analysis of synovial fluid using PCR may be decisive for making the final diagnosis of LA.

Antibodies, Bacterial↗
PubMed1999

Molecular characterization of MRJP3, highly polymorphic protein of honeybee (Apis mellifera) royal jelly.

Major proteins of honey bee (Apis mellifera) royal jelly are members of the MRJP protein family. One MRJP protein termed MRJP3 exhibits a size polymorphism as detected by SDS-PAGE. In this report we show that polymorphism of the MRJP3 protein is a consequence of the polymorphism of a region with a variable number of tandem repeats (VNTR) located at the C-terminal part of the MRJP3 coding region. We present the characterization of five polymorphic alleles of MRJP3 by DNA sequencing. By PCR analyses, at least 10 alleles of distinct sizes were found in randomly sampled bees. Studies with nurse bees from a single honeybee colony revealed both Mendelian inheritance and very high variability of the MRJP3 genomic locus. The high variability and simple detection of the MRJP3 polymorphism may be useful for genotyping of individuals in studies of the honeybee.

Alleles↗
PubMed1999

The EMB 506 gene encodes a novel ankyrin repeat containing protein that is essential for the normal development of Arabidopsis embryos.

The EMB 506 gene of Arabidopsis, required for the normal development of the embryo beyond the globular stage, has been cloned. The gene encodes a protein of predicted size 35 kDa that contains five ankyrin (ANK) repeats within the C terminal moiety. ANK repeats are conserved domains of 33 amino acids involved in specific recognition of protein partners. The EMB 506 protein was detected at different stages of silique development but accumulated preferentially in the mature cauline leaves. The rescue of homozygous emb 506 embryos by complementation with the wild-type sequence cDNA demonstrated that the emb mutation is a consequence of the T-DNA insertion and that integration and expression of the transgene occurred during gametogenesis and/or early embryo development. In addition to the drastic effect of the emb 506 mutation during embryo development, complementation experiments revealed another effect of the gene: emb 506 plants transformed with the wild-type EMB 506 sequence were able to produce viable seeds but showed a reduction of apical dominance and the presence of adventitious buds or bracts along the stem. This result supports the idea that genes essential for embryogenesis may also be required at other stages of the plant life cycle.

Amino Acid Sequence↗