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Biomedical subjects

S Albert

Publications and source records attributed to S Albert.

At least 55 records · Page 3Linked to original sources
PubMed1999

Intronic enhancers control expression of zebrafish sonic hedgehog in floor plate and notochord.

The signalling molecule Sonic hedgehog (Shh) controls a wide range of differentiation processes during vertebrate development. Numerous studies have suggested that the absolute levels as well as correct spatial and temporal expression of shh are critical for its function. To investigate the regulation of shh expression, we have studied the mechanism controlling its spatial expression in the zebrafish. We employed an enhancer screening strategy in zebrafish embryos based on co-injection of putative enhancer sequences with a reporter construct and analysis of mosaic expression in accumulated expression maps. Enhancers were identified in intron 1 and 2 that mediate floor plate and notochord expression. These enhancers also drive notochord and floor plate expression in the mouse embryo strongly suggesting that the mechanisms controlling shh expression in the midline are conserved between zebrafish and mouse. Functional analysis in the zebrafish embryo revealed that the intronic enhancers have a complex organisation. Two activator regions, ar-A and ar-C, were identified in intron 1 and 2, respectively, which mediate mostly notochord and floor plate expression. In contrast, another activating region, ar-B, in intron 1 drives expression in the floor plate. Deletion fine mapping of ar-C delineated three regions of 40 bp to be essential for activity. These regions do not contain binding sites for HNF3beta, the winged helix transcription factor previously implicated in the regulation of shh expression, indicating the presence of novel regulatory mechanisms. A T-box transcription factor-binding site was found in a functionally important region that forms specific complexes with protein extracts from wild-type but not from notochord-deficient mutant embryos.

Animals↗
PubMed1998

A family of major royal jelly proteins of the honeybee Apis mellifera L.

The characterization of major proteins of honeybee larval jelly (49-87 kDa) was performed by the sequencing of new complementary DNAs (cDNAs) obtained from a honeybee head cDNA library, by the determination of N-terminal sequences of the proteins, and by analyses of the newly obtained and known sequence data concerning the proteins. It was found that royal jelly (RJ) and worker jelly (WJ) contain identical major proteins and that all the proteins belong to one protein family designated MRJP (from Major Royal Jelly Proteins). The family consists of five main members (MRJP1, MRJP2, MRJP3, MRJP4, MRJP5). The proteins MRJP3 and MRJP5 are polymorphic. MRJPs account for 82 to 90% of total larval jelly protein, and they contain a relatively high amount of essential amino acids. These findings support the idea that MRJPs play an important role in honeybee nutrition.

Amino Acid Sequence↗
PubMed1998

[Diagnosis of pneumonia in long-term ventilated patients. Value of digital luminescence radiography in comparison with clinical and microbiological monitoring].

PURPOSE: Pulmonary infection is one of the most feared complications in patients receiving long-term ventilation. We evaluated prospectively the diagnostic value of daily bedside chest radiography performed as digital luminescence radiography (DLR) in comparison to clinical findings and quantitative microbial culture. MATERIAL AND METHODS: Prospective evaluation of daily bedside chest radiography (DLR) and clinical parameters such as blood count, body temperature, and microbiological monitoring (quantitative culturing, microscopy) of 20 patients receiving long-term ventilation was undertaken. Altogether 325 chest radiographs were evaluated. RESULTS: 96% of the routine radiographs showed abnormal findings. Nosocomial pneumonia was suspected in 31% of all 330 days of observation by means of clinical and microbiological findings. DLR showed correct findings in 80% of this days (right-positive interpretation); a false-positive interpretation was resulted in 16 radiographs. Most common finding in nosocomial pneumonia was an alveolar pattern with air bronchogram. Fever and leucocytosis often precede radiological evidence of pneumonia. CONCLUSION: Daily bedside chest radiography performed as DLR shows abnormal finding in a high percentage. Bedside chest radiograph is in accordance to clinical and microbiological finding of nosocomial pneumonia in 80%.

Adult↗
PubMed1997

[Unstable angina pectoris in intermittent left bundle branch block].

We present a case report of a 57 year old woman with recurrent chest pain, initially exclusively at exercise and later also at rest. This led to an emergency hospitalization for suspected myocardial infarction. As there were no enzymatic and electrocardiographic signs of acute infarction she was treated, as unstable angina pectoris. Coronary angiography revealed but a modest coronary atheromatosis without significant coronary stenosis. Therefore her symptoms were interpreted as primary manifestation of an intermittant Left Bundle Branch Block (LBBB) with changing heart-rate dependency. A majority of patients with LBBB and chest pain have a relevant Coronary Artery Disease (CAD). There is a small number of reports in literature about patients with intermittant LBBB without significant CAD but with both typical (exercise-induced) and atypical (at rest) chest pain. Special features of our case are presentation of LBBB as unstable angina, documentation of an intermittant LBBB with changing heart-rate dependency and heart-rate-dependent supranormal conduction in the left bundle branch. We review some important aspects of LBBB with regard to this case.

Angina, Unstable↗
PubMed1997

Isolation and characterization of the droPIK57 gene encoding a new regulatory subunit of phosphatidylinositol 3-kinase from Drosophila melanogaster.

Mammalian phosphatidylinositol 3-kinase (PI 3-kinase) plays an important role in the regulation of various cellular, receptor tyrosine kinase-mediated processes, such as mitogenesis and transformation. PI 3-kinase is composed of a 110-kDa catalytic subunit and a regulatory subunit of 85 kDa or 55 kDa. We have cloned a gene for a regulatory subunit from Drosophila melanogaster, named droPIK57, from head-specific cDNA libraries. The droPIK57 gene encodes a protein containing two SH2 domains with significant sequence homology to those in p85 and p55. Like the p55 subunits, DroPIK57 is missing the SH3 domain and the bcr homology region of the p85 subunit. The short N-terminus as well as the C-terminus of the DroPIK57 protein show no identity to the known PI 3-kinase subunits, suggesting that it is a new member in the family of regulatory subunits. In-situ hybridization and Northern blot analysis indicate a widespread function of this gene during embryogenesis and in the CNS.

Amino Acid Sequence↗
PubMed1997

The absence of an apolipoprotein epsilon4 allele is associated with a more aggressive form of Alzheimer's disease.

We investigated the relationship between APOE genotype and rate of disease progression and survival in 99 patients with probable Alzheimer's disease (AD) who were followed biannually for up to 6 years. Patients were stratified into two groups, those with and without at least one APOE epsilon4 allele. The rate of decline in modified Mini-Mental State Examination scores was slower, the presence of extrapyramidal signs was decreased, and the development of myoclonus occurred later among patients with APOE epsilon4 alleles compared with patients with other genotypes. Compared with patients without an APOE epsilon4 allele, the risk of mortality was also decreased in patients with at least one epsilon4 allele (RR = 0.38; CI = 0.17-0.84, p < 0.02). Because the decline in mental ability as well as the development of myoclonus and extrapyramidal signs are consistent manifestations of disease progression, our results imply that APOE epsilon4 is associated with a less aggressive form of AD.

Age of Onset↗
PubMed1997

Intensity Measurements of Deltal > 1 Transitions of Several Isotopomers of HCN

The intensities of the forbidden Q-branch transitions 02(2f)0-00(0)0, 12(2f)0-00(0)0, and 02(2f)1-00(0)0 for HCN have been measured. The intensities of the 02(2f)0-00(0)0 transitions of DCN, D13C15N, and H12C15N were also measured, as well as the 02(2f)1-00(0)0 transitions of H12C15N and H13C15N. These Q-branch transitions are forbidden even when the effects of l-type resonance are considered so they must get their intensity from some other Coriolis interactions. The much stronger P- and R-branch lines for the e levels of these same vibrational transitions were also measured and they are shown to get most of their intensity from l-type resonance. However, the same Coriolis resonance that gives intensity to the Q-branch transitions seems to affect the DeltaJ = &plusmn;1 transitions as shown by the difference in the intensities of the DeltaJ = +1 and DeltaJ = -1 transitions. Measurements of the intensity of the 03(3e)0-00(0)0 and 03(3f)0-00(0)0 transitions shows that they derive most, but perhaps not all, of their intensity from l-type resonance. An unsuccessful search for forbidden DeltaJ = 0, e-e transitions for the strong 10(0)0-00(0)0 band shows that there is no detectable mixing of the e and f levels. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Role of quantitative cultures and microscopic examinations of endotracheal aspirates in the diagnosis of pulmonary infections in ventilated patients.

Endotracheal aspirates (EA) from 20 intubated patients in a surgical intensive care unit (mean ventilation time/patient = 16.5 days) were investigated serially by performing quantitative cultures using growth of 10(5) cfu/mL as a cut-off point. Microscopic examinations were made using Giemsa's stain for polymorphonuclear neutrophils (PMN). The spectrum of pathogens encountered was determined and compared with clinical data to distinguish colonization from infection of the lower respiratory tract. Out of 301 EA cultures, 156 (51.8%) were positive and 145 (48.2%) were below the cut-off point. Counts of PMN were significantly higher in samples which gave positive cultures. Seventy-five different bacterial strains were isolated (64% were Gram-negative bacilli). Seventeen patients (85%) were colonized with Gram-negative bacteria. Nine patients (45%) developed nosocomial pneumonia (NP), five (25%) had no signs of pneumonia, and six (30%) had an uncertain status. Main causative agents for NP were Pseudomonas aeruginosa, Enterobacteriaceae and Staphylococcus aureus. Quantitative EA cultures had a sensitivity of 81.5%, a specificity of 64.8%, a positive predictive value of 55% and a negative predictive value of 87%. Our results suggest that EA quantitative cultures (cut-off value 10(5) cfu/mL), species identification and microscopic examination of EA may help to differentiate tracheobronchial colonization and infection, especially when bronchoscopic techniques are not available.

Adult↗
PubMed1997

BANYULS, a novel negative regulator of flavonoid biosynthesis in the Arabidopsis seed coat.

A mutant of Arabidopsis that accumulates a high level of red pigments within the seed coat has been isolated from a population of T-DNA-transformed plants. Genetic analysis revealed that the mutation is recessive and affects maternal seed tissues only. Due to the color of the immature seeds, this mutation was named banyuls (ban). Pigments accumulated continuously from early seed development to the desiccation stage in the seed coat of the mutant. The phenotype of the double mutant banyuls/ transparent testa confirmed the flavonoid nature of the pigments and enabled assignment of the regulatory TT (Transparent Testa) genes to two groups according to their epistatic relationship to ban. The flavonoid content of germinated ban and wild-type seedlings was similar. Plants harbouring the ban mutation had a normal formation of trichomes and root hairs and were not affected in their responses to light. The seeds of ban plants exhibited reduced germination compared to wild-type which may be a direct consequence of the high level of pigments. These results suggest that BANYULS functions as a negative regulator of flavonoid biosynthesis that prevents accumulation of pigments in the seed coat during early embryogenesis in Arabidopsis.

Anthocyanins↗
PubMed1997

Cross-cultural neuropsychological assessment: a comparison of randomly selected, demographically matched cohorts of English- and Spanish-speaking older adults.

As the US population of elderly Hispanics continues to grow, there is an increasingly greater need for neuropsychological measures that are appropriate for assessing Spanish-speaking elders. The current study compared the performance of randomly selected, community-based samples of English- and Spanish-speaking elders on a brief neuropsychological test battery. Subject groups were matched for age and education. Multivariate analysis indicated significant group differences on the test battery. English and Spanish speakers scored comparably on many language-based tasks, but Spanish speakers scored significantly lower on almost all of the nonverbal measures. Significant group differences were observed on multiple-choice matching and recognition memory for stimuli from the Benton Visual Retention Test, as well as on Identities and Oddities from the Mattis Dementia Rating Scale, category fluency, and Complex Ideational Material from the Boston Diagnostic Aphasia Examination (BDAE). Results suggest that caution is warranted when using nonverbal as well as verbal measures to assess non-English-speaking individuals.

Adult↗
PubMed1997

An association between head circumference and Alzheimer's disease in a population-based study of aging and dementia.

We investigated the association between head circumference (HC) and Alzheimer's disease (AD) in a cross-sectional population-based study of aging in North Manhattan. Six hundred forty-nine subjects underwent neurologic, neuropsychological, and anthropometric evaluations; apolipoprotein E (apoE) genotype was available for a subsample of 300 individuals. Logistic regression analyses were performed with AD the outcome of interest to evaluate any association between HC and AD. In these analyses, HC evaluated as a continuous variable was associated with AD (OR 0.8, 95% CI 0.7-0.9) after adjusting for age, education, and ethnicity, gender, and height. Analyses suggested that increased risk resided mainly in those with smallest HC. Thus, women whose HC was within the lowest quintile of HC for women were 2.9 (95% CI 1.4-6.1) times more likely to have AD, after adjusting for age, education, and ethnicity; and men in the lowest quintile of HC (for men) were 2.3 times more likely to have AD (95% CI 0.6-9.8). There was no confounding by height, weight, or apoE genotype. The results are consistent with previous studies that suggest that premorbid brain size may influence the age-specific risk for AD. Future epidemiologic studies seeking environmental risk factors for AD may benefit by making HC measurements on all subjects to decrease the variance associated with other potential risk factors.

Aged↗
PubMed1996

Infrared Transitions of H12C14N and H12C15N between 500 and 10 000 cm-1

We have measured the Fourier transform spectrum (FTS) of two isotopomers of hydrogen cyanide (H12C14N and H12C15N) from 500 to 10 000 cm-1. The infrared data have been combined with earlier published microwave and submillimeter-wave measurements. From this analysis new vibration-rotation energy levels and constants are given, based on the observation of a number of new vibrational levels, especially for H12C15N. The Coriolis interaction involving Deltav3 = -1, Deltav2 = 3, and Deltal = &plusmn;1 has been observed for a great many levels and in some cases the assignments of laser transitions allowed by this interaction are more clearly shown. New vibration-rotation constants are given that allow one to predict the transition wavenumbers for most of the transitions below 10 000 cm-1 with accuracies of about 0.5 cm-1 or better. Values are given for the power series expansion of the l-type resonance constants and for the centrifugal distortion constants, as well as the usual vibrational and rotational constants.

Journal Article↗
PubMed1996

Induction and expression of seed-specific promoters in Arabidopsis embryo-defective mutants.

In order to assess the importance of morphogenesis on the induction of promoter markers for storage and Lea programmes, advantage was taken of the emb mutations producing embryos arrested at a wide range of developmental stages in Arabidopsis. These embryos are viable during their stage of developmental arrest and continue to divide further, but apparently without further differentiation into the main organs and tissues of the normal embryos. Eight independent emb mutants arrested in their development prior to the cotyledon stage were selected. These emb embryos lack the normal morphology of the wild-type embryos when the synthesis of storage and Lea proteins are normally initiated. The 2S1-uidA chimeric gene, representative of the maturation programme and the Em 1-uidA chimeric gene, representative of the desiccation programme were introduced by crosses into the emb background. In the eight emb lines, the expression of the GUS reporter gene directed by the 2S1 and Em 1 promoters was observed in the aborted seeds irrespective of their stage of developmental arrest. The time of induction of the expression of both promoters was the same in the arrested embryos as compared with the normal embryos within the same silique. Thus, the activation of these two promoters is triggered by the same signal and can occur in the absence of morphogenesis. However, in the absence of normal organ formation, the expression of the reporter gene under the control of the 2S1 and Em1 promoters was evident throughout the whole seed tissues. In normal seed development, the hormone abscisic acid (ABA) activates the promoters of the 2S1 and Em 1 genes. One of the important members of the signal transduction pathway of ABA is the ABI3 protein. It has been shown previously that this protein is a prerequisite for the induction of Em 1 by ABA in seeds. A good correlation with the expression of the ABI3 promoter and the 2S1 and Em 1 promoters was found in emb seeds tissues. This observation suggests that the promoters of the 2S1 and the Em 1 genes are expressed in the mutant seeds not at a basal level, but are probably induced by ABA, as in normal seed development.

2S Albumins, Plant↗
PubMed1995

[Postmortem diagnosis of tropical malaria].

Thirteen days after returning from a four week holiday in Kenya a 35-year-old man consulted his doctor complaining of feeling unwell. The doctor diagnosed influenza and gave him a sickness certificate for three days. Because the patient did not reappear at his workplace a search was made and he was found dead in his flat seven days after seeing his doctor. A medicolegal autopsy was performed two days after the estimated time of death. There was marked swelling of liver and spleen together with jaundice and "dirty grey" colouration of the viscera. Samples of heart blood and spleen puncture material were taken. Giemsa stained preparations (ordinary and thick blood smears) revealed numerous objects 1.2 to 1.5 microns in size with indistinct reddish blue staining, some of them arranged in rosettes reminiscent of schizonts. A few of them contained pigment. In material from the spleen there were masses of blackish-brown pigment. The malaria immunofluorescence test performed on serum gave a weakly positive titre of 1:40. The findings were considered enough to support a diagnosis of fulminant falciparum malaria, and this was confirmed by histological changes in various organs, notably the typical capillary blockages in the brain. Because of the popularity of long-haul tourism, cases of imported malaria are increasingly frequent and, in view of the insidiously progressive course of the disease, it should always be considered in the differential diagnosis. In cases of unexplained death, if there is any suspicion of malaria, blood should always be taken for appropriate investigations, in addition to blocks for histological examination.

Adult↗
PubMed1995

Molecular and genetic analysis of the Drosophila mas-1 (mannosidase-1) gene which encodes a glycoprotein processing alpha 1,2-mannosidase.

Glycosylation is an important mechanism for modulating the physicochemical and biological properties of proteins in a stage- and tissue-specific manner. The enzymology of this process is just beginning to be understood. Here we present the molecular analysis of mas-1 (mannosidase-1), a Drosophila gene with significant homologies to mammalian and Saccharomyces cerevisiae glycoprotein processing alpha 1,2-mannosidases. An enhancer-trap P-element inserted upstream of mas-1 leads to highly specific lacZ expression in the lobula plate giant neurons, cells that mediate the large-field optomotor response. This staining, however, seems to reflect only a small part of the complex expression pattern of the mas-1 gene: Two promoters produce alternative transcripts that show individual spatial distributions during embryonic development, including a maternal contribution. Both transcripts code for type II transmembrane proteins which differ in their N-terminal parts. Null mutants in mas-1 display defects in the embryonic PNS, in the wing, and in the adult eye. These findings illustrate that the processing of N-linked glycans plays a functional role in Drosophila development. There is, however, ample evidence for genetic and biochemical redundancy in the mannose-trimming steps of this pathway.

Amino Acid Sequence↗