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N Rosenzweig

Publications and source records attributed to N Rosenzweig.

At least 19 recordsLinked to original sources
PubMed2006

Microsatellite markers identify three lineages of Phytophthora ramorum in US nurseries, yet single lineages in US forest and European nursery populations.

Analysis of 12 polymorphic simple sequence repeats identified in the genome sequence of Phytophthora ramorum, causal agent of 'sudden oak death', revealed genotypic diversity to be significantly higher in nurseries (91% of total) than in forests (18% of total). Our analysis identified only two closely related genotypes in US forests, while the genetic structure of populations from European nurseries was of intermediate complexity, including multiple, closely related genotypes. Multilocus analysis determined populations in US forests reproduce clonally and are likely descendants of a single introduced individual. The 151 isolates analysed clustered in three clades. US forest and European nursery isolates clustered into two distinct clades, while one isolate from a US nursery belonged to a third novel clade. The combined microsatellite, sequencing and morphological analyses suggest the three clades represent distinct evolutionary lineages. All three clades were identified in some US nurseries, emphasizing the role of commercial plant trade in the movement of this pathogen.

Europe↗
PubMed2004

Phenylephrine-induced neurogenic prostatitis facilitates the promotion of PIN-like lesions in rats.

BACKGROUND: Atypical prostate hyperplasia, resembling PIN lesions in men, together with chronic inflammatory exudates, have been reported after chronic administration of phenylephrine (PE). The present study aims to characterize the evolution of the expression of typical leukocyte markers immunohistochemically as correlated to the promotion of PIN lesions. METHODS: Adolescent rats received injections of PE (subcutaneously) (10 mg/kg BW/per day) and were euthanized 3, 8 hr, 1, 3, 7, 14 days thereafter. The dissected prostates were fixed in formalin, and paraffin embedded sections were cut and immunoreacted. RESULTS: PE exerted a time related bi-phasic effect on the rat prostate. A first inflammatory reaction phase took place at 3-8 hr post injection characterized by vascular dilatation, congestion, edema, and massive leukocytic infiltrate, mainly of ED1+ cells. At 24 hr, the amount of ED1+ cells decreased approaching the equivalent values of ED2+, CD8+ cells, and mastocytes. Their values remained relatively high for the rest of the experimental period. A second phase of proliferative changes, consisting of healing fibrosis as well as dysplastic epithelial lesions, similar to human PIN lesions, appeared on the 7th day. CONCLUSIONS: Neuro-immune interactions promote prostatic fibrosis and dysplastic changes; these being preceded by an acute and transient inflammatory reaction.

Adrenergic alpha-Agonists↗
PubMed2001

Molecular oxygen-sensitive fluorescent lipobeads for intracellular oxygen measurements in murine macrophages.

Intracellular oxygen concentration is of primary importance in determining numerous physiological and pathological processes in biological systems. This paper describes the development and application of micrometer-sized oxygen-sensitive fluorescence lipobeads for intracellular measurements of molecular oxygen in J774 murine macrophages. A ruthenium diimine complex [Ru(bpy-pyr)(bpy)2]C12 (bpy = 2,2'-bipyridine, bpy-pyr = 4-(1"-pyrenyl)-2,2'-bipyridine) is used as the oxygen indicator. The indicator exhibits high chemical and photostability and high sensitivity to oxygen. The indicator molecules are immobilized in a phospholipid membrane that coats polystyrene microparticles. The fluorescence of the lipobeads is effectively quenched by molecular oxygen. The fluorescence intensity of the oxygen-sensitive lipobeads is 3 times higher in a nitrogenated solution than in an oxygenated solution. The lipobeads are internalized by murine macrophages through phagocytosis. They maintain their spectral properties for 24 h in living cells when the cells are stored in phosphate-buffered saline at pH 7.4. The photostability, reversibility, and effect of hypoxia, hyperoxia, and oxidative stress on the intracellular level of oxygen in J774 murine macrophages are described.

2,2'-Dipyridyl↗
PubMed2001

Synthesis, characterization, and application of fluorescence sensing lipobeads for intracellular pH measurements.

This paper describes the synthesis and characterization of micrometric phospholipid-coated polystyrene particles, named lipobeads, with pH-sensing capability and their application for intracellular pH measurements in murine macrophages. The phospholipids used to coat the particles are labeled with fluorescein (a pH-sensitive dye) and tetramethylrhodamine (a pH-insensitive dye), which serves as a referencing fluorophore for increased accuracy of the pH measurements. The synthesis of the pH-sensing lipobeads is realized by the covalent attachment of the fluorescent phospholipids to the surface of carboxylated polystyrene particles. The pH dynamic range of the sensing particles is between 5.5 and 7.0 with a sensitivity of 0.1 pH unit. The excitation light intensity is reduced to minimize photobleaching of the fluorescein-phospholipid conjugates. The fluorescent lipobeads are used to measure the pH in single macrophages. The lipobeads are ingested by the macrophages and directed to lysosomes, which are the cellular organelles involved in the phagocytosis process. Despite the high lysosomal levels of digestive enzymes and acidity, the absorbed particles remain stable for over 6 h in the cells when they are stored in a phosphate-buffered saline solution at pH 7.4.

Animals↗
PubMed2001

Development of a digital fluorescence sensing technique to monitor the response of macrophages to external hypoxia.

Oxygen plays a very important role in living cells. The intracellular level of oxygen is under tight control, as even a small deviation from normal oxygen level affects major cellular metabolic processes and is likely to result in cellular damage or cell death. This paper describes the use of the oxygen sensitive fluorescent dye tris (1,10-phenanthroline) ruthenium chloride [Ru(phen)(3)] as an intracellular oxygen probe. Ru(phen)(3) exhibits high photostability, a relatively high excitation coefficient at 450 nm (18 000 M(-1) cm(-1)), high emission quantum yield ( approximately 0.5), and a large Stoke shift (peak emission at 604 nm). It is effectively quenched by molecular oxygen due to its long excited state lifetime of around 1 micros. The luminescence of Ru(phen)(3) decreases with increasing oxygen concentrations and the oxygen levels are determined using the Stern-Volmer equation. In our studies, J774 Murine Macrophages are loaded with Ru(phen)(3), which passively permeates into the cells. Fluorescence spectroscopy and digital fluorescence imaging microscopy are used to observe the cells and monitor their response to changing oxygen levels. The luminescence intensity of the cells decreases when exposed to hypoxia and recovers once normal oxygen conditions are restored. The analytical properties of the probe and its application in monitoring the cellular response to hypoxia are described.

Animals↗
PubMed2001

Colony growth rates of microfungal isolates from the north and south facing slopes of Evolution Canyon, Mount Carmel, Israel, after irradiation at 10(6) rads 60Co.

Species of microfungi were isolated from both the north facing slope (NFS) and the south facing slope (SFS) of Evolution Canyon, Mount Carmel, Israel. They were examined for growth rates before and after exposure to 10(6) rads of cobalt 60 irradiation. Above 10(6) rads all growth ceased after 1 day following exposure.

Cobalt Radioisotopes↗
PubMed2000

Synthesis and application of submicrometer fluorescence sensing particles for lysosomal pH measurements in murine macrophages.

Phagocytosis of bioparticles such as bacteria and viruses by macrophages is a critical component of the immune response against infections. In this paper we describe the synthesis of submicrometer fluorescent particles with pH sensing capability. The particles are used to measure the pH and to monitor the effect of chloroquine, an antimalarial drug, on the pH in the lysosome, the cellular organelle involved in the phagocytosis process. The synthesis of the pH sensing particles is realized by the covalent attachment of amine reactive forms of Oregon Green (pH sensitive dye) and Texas Red (pH insensitive dye) to the surface of amino-modified submicrometer polystyrene particles. The particles are absorbed by J774 Murine Macrophages through phagocytosis and directed to lysosomes. Despite the high lysosomal levels of digestive enzymes and acidity, the absorbed particles remain stable for 12 h in the cells when they are stored in a PBS buffer solution at pH 7.4. The pH dynamic range of the sensing particles is between pH 4.5 and 7 with a sensitivity of 0.1 pH units. Exposure of the cells to chloroquine increases the lysosomal pH from 4.8 to 6.5. The effect is concentration-dependent.

Animals↗
PubMed1998

Macroscopic variations of microfungal isolates from Evolution Canyon, Lower Nahal Oren, Mount Carmel, Haifa, Israel.

Microfungi (eleven species), isolated from both the north facing slope (NFS) and the south facing slope (SFS) of Evolution Canyon, Lower Nahal Oren, Mt Carmel, Israel, were examined for growth rates before and after exposure to cobalt 60 irradiation. Growth rates, morphology, and sporulation varied for the same species according to isolates recovered from the NFS, SFS, and carbon sources. In addition, the Mucor haemalis sexual zygospore production was monitored.

Biological Evolution↗
PubMed1997

Cobalt 60 radiation and growth of eleven species of micro-fungi from Evolution Canyon, Lower Nahal Oren, Israel.

Eleven micro-fungal species isolated from both the north facing slope (NFS) and the south facing slope (SFS) of Evolution Canyon, Lower Nahal Oren, Israel, were examined for growth rates before and after exposure to 60Co irradiation. Species of Alternaria, Aspergillus, Humicola, Oidiodendron, and Staphylotrichum from SFS grew faster than the NFS isolates while Fusarium, Sordaria, and Stachybotrys grew at greater rates from the NFS than from the SFS. Mucor and Ulocladium isolates grew at the same rate from both SFS and NFS. The eleven isolates from each slope were next subjected to 60Co irradiation. At 40,000 rads exposure, Alternaria, Fusarium, and Stachybotrys grew more rapidly when isolated from the NFS, while Humicola and Staphylotrichum grew at a faster rate when isolated from the SFS. Aspergillus, Mucor, Sordaria, and Ulocladium from both the NFS and the SFS had relatively the same growth rate at 40,000 rads exposure. At 400,000 rads exposure, growth rates remained much the same for both the N and S exposed isolates as they were at 40,000 rads. Above 10(6) rads, growth ceased but recovery occurred at various times for individual isolates of the same species from opposing canyon slopes.

Alternaria↗
PubMed1995

Cell cycle arrest induced by an inhibitor of glucosylceramide synthase. Correlation with cyclin-dependent kinases.

In an attempt to define the basis for sphingolipid regulation of cell proliferation, we studied the effects of glucosylceramide (GlcCer) synthase inhibition by threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) on NIH 3T3 cells overexpressing insulin-like growth factor-1 (IGF-1) receptor. PDMP treatment resulted in a time-dependent decrease in GlcCer levels and an increase in cellular ceramide levels. PDMP abolished serum and IGF-1-stimulated cell proliferation, as measured by a reduction in [3H]thymidine incorporation, protein, and DNA levels. However it did not affect IGF-1-mediated early signaling events, including receptor tyrosine kinase, MAP kinase, and phosphatidylinositol 3-kinase activities. Two-color flow cytometry with propidium iodide and 5-bromo-2'-deoxyuridine monophosphate labeling revealed an arrest of the cell cycle at G1/S and G2/M transitions in an asynchronous population of cells. These changes were time dependent, with maximal effects seen by 12-24 h. Removal of PDMP from the cell medium resulted in reversal of the cell cycle changes, with cells re-entering the S phase. The cell cycle arrest at the G1/S and G2/M transitions was confirmed in cells synchronized by pretreatment with nocodazole, aphidicolin, or hydroxyurea, and released from blockade in the presence of PDMP. A decrease in the activities of two cyclin-dependent kinases, p34cdc2 kinase and cdk2 kinase, was observed with PDMP treatment. When cell ceramide levels were increased by N-acetylsphingosine, comparable changes in the cell cycle distribution were seen. However, sphingomyelinase treatment was without effect. Therefore, it appears that ceramide mediates in part the inhibitory effect of GlcCer synthase inhibition on IGF-1-induced cell proliferation in 3T3 cells. The rapid production of decreased cyclin-dependent kinase activities by PDMP suggests that one of the crucial sites of action of the inhibitor lies in this area.

3T3 Cells↗
PubMed1995

Characterization of the mitogen-regulated protein (proliferin) receptor.

Mitogen-regulated protein (MRP/PLF; also called proliferin) is a member of the PRL-GH family expressed by the placenta in mid-gestation. This report describes an MRP/PLF receptor in uterine membrane preparations from pregnant mice. Peak receptor activity occurred at 11 days of gestation with a dissociation constant of 6 x 10(-10) M and maximal binding capacity of 86 fmole MRP/PLF/mg membrane protein. PRL, PL-I, and mannose-6-phosphate did not compete for binding, and GH competed weakly only at high concentrations. Primary cells cultured from uteri taken at days 8-11 of gestation responded to MRP/PLF with increases in DNA synthesis. Uterine cells from later stages of gestation did not respond to MRP/PLF. This is the first reported evidence of a function mediated by MRP/PLF and suggests a role for this protein in maternal-fetal interactions during reproduction. Thus, it seems that MRP/PLF is a placentally derived growth factor, which stimulates proliferation in the uterus in a developmentally defined period to coordinate uterine growth with fetal development.

Animals↗
PubMed1978

Psychiatric emergency service expands to serve total hospital.

A hospital with a comprehensive psychiatric service provides a nearby general hospital with staff and backup for psychiatric consultations, crisis intervention, concurrent psychiatric care of medical-surgical patients, follow-up for psychiatric hospitalization or referrals, and staff education. Personnel include senior psychiatrists and on-call residents, and the program relies heavily on use of psychiatric nursing clinical specialists and RNs with experience in psychiatric nursing.

Crisis Intervention↗
PubMed1975

Some differences between elderly people who use community resources and those who do not.

This study initially involved 120 subjects in four groups of 30 members each. It was designed to compare institutional aged persons (Jewish Home for the Aged, or JHAs) with ambulatory persons who used community resources (Jewish Community Center, JCCs). Controls were selected from a stratified sample in a community-wide study of the Detroit Jewish population; half of the control subjects lived alone (LAs) and half lived with their families (LWFs); none of them used community resources. All 120 subjects were at least 60 years old. The female:male ratio was 71:49. They were asked to fill in a 442-item questionnaire which yields data about personal and family background, current status, attitudes, interests and self-evaluation. The 30 JHAs were significantly older than the 30 JCCs, but otherwise there were few differeneces. Therefore the focus of the study was shifted to a comparison of the 30 JCCs, who used community facilities, with the 30 LAs and 30 LWFs, who did not. The JCCs were not well educated and were of low economic status. They obtained social gratification through group activities. They had many acquaintances but few close friends whose loss could be a threat. As a group, they seemed content. The LA and LWF groups were better educated, more successful financially, and more likely to derive personal satisfaction from their work. They formed closer family attachments and were more object-oriented, so they were more vulnerable to lossof home and family. Setting high value on individual capacities, they were more likely to be threatened by illness. Any attempt to extend a helping hand to elderly citizens who do not avail themselves of community resources will have to take into account the prevalence of these distinctly different life styles.

Age Factors↗