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Biomedical subjects

H Levy

Publications and source records attributed to H Levy.

At least 73 records · Page 4Linked to original sources
PubMed1993

Cbr, an algal homolog of plant early light-induced proteins, is a putative zeaxanthin binding protein.

The cbr gene, previously cloned from the unicellular green alga Dunaliella bardawil, is transcriptionally and translationally activated in parallel to accelerated carotenogenesis in response to light stress conditions. The product of cbr, structurally similar to Elips (early light-induced proteins of higher plants), is associated with a minor light harvesting complexes of photosystem II component (Levy, H., Gokhman, I., and Zamir, A. (1992) J. Biol. Chem. 267, 18831-18836). This study examines the relationship between the induction of Cbr and another plant response to light stress, the deepoxidation of violaxanthin to zeaxanthin. A parallel between the two processes was observed in cells exposed to high light, starved for sulfate, or treated with norflurazon, a herbicide inducing photooxidative damage by inhibiting de novo carotenoid biosynthesis. When highly illuminated cells were returned to normal light, Cbr decayed in parallel to the reepoxidation of zeaxanthin to violaxanthin. Evidence for the physical association of Cbr and zeaxanthin was provided by nondenaturing gel electrophoresis. In cells transferred from low to high light, zeaxanthin was associated with the faster migrating of two electrophoretically resolved fractions of light harvesting complexes of photosystem II that also contained Cbr. In cells growing under normal light, violaxanthin was bound equally to the two fractions. Based on these results we propose that Cbr/early light-induced proteins bind zeaxanthin to form photoprotective complexes within the light-harvesting antennae.

Carotenoids↗
PubMed1993

Overdose of risperidone.

Risperidone is an investigational antipsychotic agent currently being tested in an international multicenter drug trial. We report the first case of a risperidone overdose in an apparent suicide attempt. This was without serious clinical side effects and manifested mainly as ECG abnormalities.

Adult↗
PubMed1993

Dermatosis papulosa nigra in a young child.

Dermatosis papulosa nigra was diagnosed in a 3-year-old black boy. This follicular nevoid condition, which is common in adult blacks, is seldom diagnosed in prepubescent children. The diagnosis was confirmed by the biopsy specimen that showed features of epidermal acanthosis and papillomatosis, similar to seborrheic keratosis.

Black People↗
PubMed1993

A comparative study of oral endotracheal tube securing methods.

A prospective study was done to compare four different methods of securing oral endotracheal tubes: adhesive tape (A), Twill tape (T), Twill tape with FlexBlue bite block (TFXB), and Velcro tie with FlexBlue (VFXB), used on sequential days. Thirty-six patients were enrolled for 136 patient-days and 18 had complete 4-day cycles. The methods were evaluated twice daily by nurses, respiratory therapist, and patient, on a five-point Likert scale with regard to oral hygiene, patient comfort, nurse satisfaction, and ease of use. Tube movement relative to the incisor teeth was measured at end of shift, the use of a bite block was noted, and near extubations were documented. Analysis of variance and Student's t test with Bonferroni correction were performed. Adhesive tape had 33 patient-days, 0.4 +/- 0.7 cm movement, 3.4 +/- 0.9 oral hygiene, 4.0 +/- 0.8 comfort, 4.2 +/- 0.6 nurse satisfaction, and 4.2 +/- 0.7 ease of use. Twill tape had 34 patient-days, 0.7 +/- 1.1 cm movement, 3.0 +/- 0.7 oral hygiene, 3.1 +/- 0.9 comfort, 2.8 +/- 1.0 nurse satisfaction, and 3.3 +/- 1.1 ease of use. Twill tape with FlexBlue bite block had 35 patient-days, 1.3 +/- 2.0 cm movement, 2.5 +/- 1.2 oral hygiene, 1.9 +/- 1.1 comfort, 1.9 +/- 1.0 nurse satisfaction, and 2.1 +/- 1.1 ease of use. Velcro tie with FlexBlue had 34 patient-days, 0.8 +/- 1.0 cm movement, 1.9 +/- 1.2 oral hygiene, 1.5 +/- 1.4 comfort, 1.6 +/- 1.0 nurse satisfaction, and 1.8 +/- 1.1 ease of use. Statistical analysis showed no difference between the groups for tube movement. Method A was statistically superior to VFXB and TFXB on all other parameters, and T on all except oral hygiene. Twill tape was superior to VFXB on all, and TFXB on patient comfort, nurse satisfaction, and ease of use. There was no significant difference between TFXB and VFXB on any measured parameter. Adhesive tape and T required an oral airway on only 14 days compared with 69 days of FlexBlue use. Extubation on 2 and near extubation occurred on 18 occasions with FlexBlue use and only once with T and accounted for most decisions to change securing method. We cannot recommend the use of the FlexBlue system for securing oral endotracheal tubes.

Adult↗
PubMed1992

Regulation and light-harvesting complex II association of a Dunaliella protein homologous to early light-induced proteins in higher plants.

The unicellular green alga Dunaliella bardawil responds to high light, nutrient deprivation, and several other types of stress by massive accumulation of beta-carotene. We have previously cloned a nuclear gene, cbr, that is co-induced with accelerated carotenogenesis. The predicted product of cbr is closely related to early light-induced proteins (Elips) of higher plants, and also shows resemblance to chlorophyll a/b-binding proteins. In the present study, the determination of the cbr transcription start site supported the previously proposed site of translation initiation. Antibodies raised against a synthetic oligopeptide matching the predicted sequence of Cbr recognized two polypeptides of apparently 17 and 19 kDa that were induced in parallel to cbr transcript accumulation in highly illuminated or sulfate-starved D. bardawil cells. The antibodies also cross-reacted with an approximately 20-kDa polypeptide in sulfate-starved Dunaliella salina. In both D. bardawil and D. salina, Cbr was found exclusively in the thylakoid membranes. After mild solubilization, Cbr co-fractionated with light-harvesting complex II (LHCII) in sucrose gradient centrifugation and gel electrophoresis and was specifically associated with a minor LHCII complex. An occasionally observed, faster mobility Cbr form, free of LHCII, was probably released from the larger complex. These results support the conclusion that Cbr belongs to a class of stress-induced proteins transiently associated with antennae complexes.

Amino Acid Sequence↗
PubMed1992

The value of bronchoalveolar lavage and bronchial washings in the diagnosis of invasive pulmonary aspergillosis.

The objective of this study was to clarify conflicting reports of the sensitivity and specificity of bronchoalveolar lavage or bronchial washings for diagnosing invasive pulmonary aspergillosis. The study was a retrospective review of 300 consecutive patients in a tertiary referral centre subjected to 343 fiberoptic bronchoscopic procedures for the evaluation of pulmonary infiltrates. Classification of paired fungal culture and cytologic examination of bronchoalveolar lavage or bronchial washing fluid according to clinical, radiographic, histological and autopsy evidence of invasive pulmonary aspergillosis. One-hundred and fifteen deaths occurred, with a 58% autopsy rate. A diagnosis of invasive pulmonary aspergillosis was made in 21 immunosuppressed patients with 16 deaths. Bronchoalveolar lavage cytology showed aspergillus in 19 specimens (invasive pulmonary aspergillosis in 16), cultures yielded aspergillus in 41 (invasive pulmonary aspergillosis in ten), with both tests positive in nine. Cytology sensitivity was 64.0%, specificity 99.1%, positive predictive value 84.2%, and negative predictive value 97.2%. Culture sensitivity was 40.0%, specificity 90.3%, positive predictive value 24.4%, and negative predictive value 95.0%. Concordant cytology and culture sensitivity was 32.0%, specificity 99.7%, positive predictive value 88.9%, and negative predictive value 94.9%. In conclusion, when characteristic hyphae are visualized in bronchoalveolar lavage specimens from immunosuppressed patients with compatible clinical data, it is advisable to treat for presumptive invasive pulmonary aspergillosis.

Adult↗
PubMed1991

Co-regulation of a gene homologous to early light-induced genes in higher plants and beta-carotene biosynthesis in the alga Dunaliella bardawil.

Dunaliella bardawil, a unicellular green alga that can be induced to accumulate massive amounts of beta-carotene, is particularly suitable for studies of carotenogenesis regulation and its links to developmental and adaptive processes in the chloroplast. A cDNA clone corresponding to a transcript accumulating coordinately with carotenogenesis induction was isolated by differential hybridization of a cDNA library made from intensely illuminated cells. This transcript was also abundant in algal mutants able to accumulate beta-carotene under relatively low light intensity. DNA sequence analysis indicates that cbr (for carotene biosynthesis-related) is closely related to early light-induced genes (elip) of higher plants. Similarity also exists between repeated oligopeptide motifs in Cbr and Cab proteins of photosystems I and II. Three upstream direct repeats in cbr include an octamer and hexamer related to mammalian sterol regulatory elements. The relationship between cbr transcript and beta-carotene accumulation, the structural similarity between Cbr and Cab proteins, and the presence of potential SRE-1 elements lead us to propose that Cbr represents novel carotenoid binding proteins, whose synthesis might be coordinated with carotenogenic enzymes via an evolutionary conserved regulatory mechanism.

Amino Acid Sequence↗
PubMed1991

Identification of viral proteins encoded by two DNA fragments of herpesvirus of turkeys (HVT).

Herpesvirus of turkeys (HVT) vaccine is used worldwide to immunize chickens against Marek's disease (MD). Polyclonal antiserum directed against one virus cross-reacts with proteins of the other, while only 5% homology at the DNA level was demonstrated between the two viruses. A partial library of HVT DNA fragments ranging from 1.5 to 13.5 kbp in size was constructed in pBR 322. Under stringent conditions of hybridization (low salt concentration, 10% dextran sulfate at 68 degrees C), two of the cloned HVT DNA fragments (13.5 and 11.0 kbp) hybridized to three MDV DNA fragments: BamHI-C, D, and G. The 13.5 kbp fragment detected two transcripts of 1.8 and 3.0 kb in RNA extracted from HVT-infected chicken embryo fibroblasts, while the 11.0 kbp fragment detected three transcripts of 1.6, 2.0, and 3.0 kb in the extracted RNA. Using hybrid selection, specific RNA was isolated by hybridization with the two cloned HVT DNA fragments and then was translated in vitro using rabbit reticulocyte lysate, and the resulting proteins were analyzed by NaDodSO4-PAGE. The RNA selected by the two HVT DNA fragments coded for a 30 kD protein and for several smaller proteins 10-20 kD in size, while the RNA selected by the 11.0 kb HVT DNA fragment was translated into a 40 kD protein. Immunoprecipitation of these in vitro synthesized proteins with hyperimmune anti-HVT chicken serum showed that they were of viral origin.

Animals↗
PubMed1991

Molecular aspects of Gaucher disease.

Gaucher disease is the most common sphingolipid storage disorder. Due to its high prevalence it may appear with a nonrelated neurological disease and be misinterpreted as Gaucher type 3. A family is described in which 2 Gaucher brothers presented different clinical signs. Molecular analysis has shown that both carried two mutated alleles. One allele had a G to C transversion at nucleotide 3119 of the active gene (Asp140-His) while the other presented two base pair changes, an A to C transversion at nucleotide number 3170 (Lys157-Gly), and a G-A transition at nucleotide number 5309 (Glu324-Lys). Therefore, both presented the same type of Gaucher disease which was accompanied with a nonrelated neurological disease in one of them. Molecular diagnosis of 161 patients has provided a relative abundance of different mutations among Jewish and non-Jewish patients and allowed some genotype-phenotype correlation. Differential expression of the murine glucocerebrosidase activator gene (the prosaposine) has been demonstrated using Northern technique and in situ hybridization. High expression levels were observed in the brain and testes. In the testes the prosaposine expression was confined to the supporting cells. In the female gonad prosaposine expression has also been shown, in the corpus luteum. In a 12 1/2-day-old embryo, prosaposine gene expression was detected mainly in brain stem, in dorsal ganglia and in the genital ridge.

Adolescent↗
PubMed1991

Comparison of bacteraemic community-acquired lobar pneumonia due to Streptococcus pneumoniae and Klebsiella pneumoniae in an intensive care unit.

In a study of 41 consecutive patients with bacteraemia-associated community-acquired lobar pneumonia due to Streptococcus pneumoniae and Klebsiella pneumoniae an attempt was made to determine whether distinguishing criteria of disease due to these organisms could be identified according to demographic features and the results of initial clinical and laboratory investigations. Such information would aid in the early initiation of appropriate antimicrobial therapy. The most significant difference between the two groups of patients was the lower platelet count in the K. pneumoniae group (p less than 0.005). In addition leucopenia (p less than 0.05), higher serum albumin (p less than 0.05), and the male sex (p less than 0.05) featured with an increased frequency in patients with pulmonary infection due to K. pneumoniae. Initial antimicrobial therapy in critically ill patients with community-acquired lobar pneumonia and thrombocytopenia, particularly when associated with leucopenia and in male patients, should include agents effective against K. pneumoniae.

Adult↗