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Biomedical subjects

S Cohen

Publications and source records attributed to S Cohen.

At least 127 records · Page 7Linked to original sources
PubMed2000

Foldable silicone versus poly(methyl methacrylate) intraocular lenses in combined phacoemulsification and trabeculectomy.

PURPOSE: To compare the outcome of phacotrabeculectomy with implantation of poly(methyl methacrylate) (PMMA) or foldable silicone intraocular lenses (IOLs). METHODS: Thirty patients were randomized to receive a 5.5 mm PMMA IOL through a 5.0 mm incision or a foldable silicone IOL (Allergan SI-30) through a 3.2 mm incision. Visual acuity, intraocular pressure (IOP), bleb survival, inflammation, endothelial cell changes, and complications were examined at intervals up to 6 months. RESULTS: There was no difference between the 2 groups in final visual outcome, final IOP control, bleb survival, and endothelial cell changes. Two months after surgery, there was significantly more inflammation in the silicone IOL group than in the PMMA group (P <. 05). The silicone group had a significantly higher combined complication rate including iris capture, choroidal effusion, and epiretinal membrane formation (P <.05). CONCLUSIONS: Foldable silicone IOLs were comparable to conventional PMMA lenses in visual outcome, IOP control, bleb formation, and endothelial changes. However, some silicone lenses are associated with an increased risk of recurrence of inflammation and a higher final complication rate in combined cataract and filtration surgery.

Aged↗
PubMed2000

Molecular cloning and expression analysis of a mouse UDP-GlcNAc:Gal(beta1-4)Glc(NAc)-R beta1,3-N-acetylglucosaminyltransferase homologous to Drosophila melanogaster Brainiac and the beta1,3-galactosyltransferase family.

We have isolated a murine cDNA coding for a beta1,3-N-acetylglucosaminyltransferase enzyme ( beta3GnT). This enzyme is similar in sequence to Drosophila melanogaster Brainiac and to the murine and human beta1,3-galactosyltransferase family of proteins. The mouse beta 3GnT protein is 397 amino acids in length and contains 7 cysteine residues that are conserved in the human orthologue. beta 3GnT is a type II membrane protein localized to the Golgi apparatus. Enzyme assays with recombinant mouse beta 3GnT reveal that it has a preference for acceptors with Gal(beta1-4)Glc(NAc) at the non-reducing termini. Proton NMR analysis of product showed incorporation of GlcNAc in beta1,3 linkage to the terminal Gal of Gal(beta1-4)Glc(beta1-O-benzyl). Northern blot analysis revealed the presence of a single 3.0[emsp4 ]kb transcript in all adult mouse and human organs tested, with highest levels in the kidney, liver, heart and placenta. The beta 3GnT gene is also expressed in a number of tumor cell lines. The human orthologue of beta 3GnT is located on chromosome 2pl5.

Amino Acid Sequence↗
PubMed2000

Group support interventions for women with breast cancer: who benefits from what?

Research on the benefits of social support groups has been inconclusive. One reason is that individual differences in intervention responses have rarely been examined. The authors determined the extent to which individual difference variables moderated the effects of an information-based educational group and an emotion-focused peer discussion group on the mental and physical functioning of women with breast cancer (n = 230). The authors administered the SF-36 (S.E. Ware, K.K. Snow, M. Kosinski, & B. Gandek, 1993), a multidimensional quality of life instrument, pre- and postintervention. Educational groups showed greater benefits on the physical functioning of women who started the study with more difficulties compared with less difficulties (e.g., lacked support or fewer personal resources). Peer discussion groups were helpful for women who lacked support from their partners or physicians but harmful for women who had high levels of support. Implications of these results for clinical interventions are discussed.

Adult↗
PubMed2000

Pass it on?

Pointers for managers to ensure safe, successful delegating practices.

Humans↗
PubMed2000

Comparison study for identifying promoter allelic polymorphism in interleukin 10 and tumor necrosis factor alpha genes.

Cytokines such as tumor necrosis factor (TNF)-alpha and Interleukin (IL)-10 play significant roles in autoimmunity and transplantation tolerance. Allelic polymorphisms that occur in the regulatory regions of these cytokine genes are closely associated with acute and chronic transplant rejection. The presence of a G-to-A polymorphism at position -308 in the promoter region of the TNF-alpha gene can increase transcription six- to sevenfold. Likewise, the G-A polymorphism at position -1082 of the IL-10 promoter results in lower levels of IL-10 protein. Accordingly, a genotype that dictates the production of high levels of TNF-alpha with low IL-10 capabilities is most likely to generate an inflammatory environment that is less receptive to the transplant. The potential for determining a patient's haplotype before transplantation may be an effective way of monitoring the post-transplant status of such patients. A variety of methodologies that address the detection of mutations have been used both in research and clinical diagnostic tests. This study analyzes the genetic variations in cytokines using two methodologies: the traditional allele-specific oligonucleotide (ASO) polymerase chain reaction (PCR) and the newer and more flexible Invader technology. The sensitivity and specificity of the Invader assay for simultaneous investigation of multiple targets makes it a useful tool in such analyses.

Alleles↗
PubMed2000

Cytological and molecular evidence that the whitefly-transmitted cucumber vein yellowing virus is a tentative member of the family Potyviridae.

Cucumber vein yellowing virus (CVYV) is widespread in cucurbits in the Middle East. CVYV has filamentous particles and is transmitted by Bemisia tabaci by the semi-persistent mode. It has not yet been assigned to a specific genus or family. Ultramicroscopic observations revealed numerous cylindrical cytoplasmic inclusions in melon and cucumber cells infected by CVYV isolates from Israel and Jordan. Depending on the section orientation, the inclusions appeared as pinwheels or as bundles. In addition, a 1.9 kb DNA fragment was amplified by RT-PCR from CVYV-infected plant extracts using primers designed to detect all potyvirids. Sequence comparisons with the amplified fragment indicated that CVYV is more closely related to Sweet potato mild mottle virus than to any other virus in the family Potyviridae: These results suggest that CVYV can be considered as a tentative new member of the genus Ipomovirus:, family Potyviridae:

Amino Acid Sequence↗
PubMed2000

Attenuated nontoxinogenic and nonencapsulated recombinant Bacillus anthracis spore vaccines protect against anthrax.

Several highly attenuated spore-forming nontoxinogenic and nonencapsulated Bacillus anthracis vaccines differing in levels of expression of recombinant protective antigen (rPA) were constructed. Biochemical analyses (including electrospray mass spectroscopy and N terminus amino acid sequencing) as well as biological and immunological tests demonstrated that the rPA retains the characteristics of native PA. A single immunization of guinea pigs with 5 x 10(7) spores of one of these recombinant strains, MASC-10, expressing high levels of rPA (>/=100 microgram/ml) from a constitutive heterologous promoter induced high titers of neutralizing anti-PA antibodies. This immune response was long lasting (at least 12 months) and provided protection against a lethal challenge of virulent (Vollum) anthrax spores. The recombinant B. anthracis spore vaccine appears to be more efficacious than the vegetative cell vaccine. Furthermore, while results clearly suggest a direct correlation between the level of expression of PA and the potency of the vaccine, they also suggest that some B. anthracis spore-associated antigen(s) may contribute in a significant manner to protective immunity.

Animals↗
PubMed2000

Impact of sample type on rapid detection of influenza virus A by cytospin-enhanced immunofluorescence and membrane enzyme-linked immunosorbent assay.

Cytospin-enhanced direct fluorescent-antibody assay (DFA) detected 49 (92.5%) and rapid membrane enzyme-linked immunosorbent assay (ELISA) detected 40 (75.5%) of 53 influenza virus A-positive samples. All 15 positive nasopharyngeal aspirates from children were detected by both tests. In contrast, 34 of 38 (89.5%) positive swabs from adults were detected by DFA, but only 25 (66%) were detected by ELISA.

Adult↗
PubMed2000

Comparison of morphological measurements extracted from digitized dental radiographs with lumbar and femoral bone mineral density measurements in postmenopausal women.

BACKGROUND: We set out to determine whether morphologic measurements extracted from digitized images of bite-wing radiographs correlated with lumbar and femoral bone mineral density (BMD) measurements in 45 postmenopausal women who had no or only mild periodontal disease (no probing depths >5 mm). METHODS: Lumbar spine and femoral BMDs were determined by dual-energy x-ray absorptiometry. Vertical bite-wing radiographs were taken and digitized. Crestal and apical regions of interest (ROIs) were drawn on the digital images of the maxillary and mandibular alveolar bone on the patient's right and left sides. For each patient, a single morphologic measurement was made for each of 8 ROIs. Correlation analysis was performed to determine the strengths of the relationships between the morphologic measurements made at the 8 locations and between these morphologic measurements and BMD measurements. RESULTS: The correlations (r) between the morphologic operator (MO) measurements and lumbar spine and femoral BMDs were weak (mean r = 0.02, range = 0.32 to -0.26) and not statistically significant, with no clear trends discernible. Correlations between MO measurements made at the 8 alveolar sites were also weak (mean r = 0.05, range = 0.35 to -0.38) and not statistically significant. CONCLUSIONS: The MO measurements used in this study were weakly correlated with lumbar spine and femoral BMDs, with no clear trends discernible in this population of postmenopausal women with no or mild periodontal disease.

Absorptiometry, Photon↗
PubMed2000

Alveolar bone height and postcranial bone mineral density: negative effects of cigarette smoking and parity.

BACKGROUND: Our objective was to test the association between cemento-enamel junction, alveolar-crest distance (CEJ-AC, as measured on digitized vertical bite-wing radiographs) and postcranial bone mineral density (BMD) relative to clinical, dietary, and demographic variables. METHODS: Data were collected in a cross-sectional study of 134 postmenopausal women. CEJ-AC distances were determined from digitized vertical bite-wing radiographs. Lumbar spine and proximal femur BMDs were determined from dual-energy x-ray absorptiometric scans. Correlation analysis and Student t tests were used to identify those variables most associated with CEJ-AC distance. The selected variables were modeled with a backward stepwise regression analysis, with CEJ-AC distance as the dependent variable. RESULTS: Parity (number of pregnancies to term), cigarette smoking, and the interaction of lateral spine BMD with cigarette smoking were independent predictors of CEJ-AC distance (P < or =0.05). Statistical models containing these variables accounted for 19% of the variation in CEJ-AC distances. CONCLUSIONS: CEJ-AC distance in postmenopausal women is the result of a complicated interaction of many effects, including but not limited to, parity, cigarette smoking, and skeletal BMD.

Absorptiometry, Photon↗
PubMed2000

A new compact medical kit on El Al passenger aircraft.

El Al was one of the first international airlines to introduce a medical kit (MK) on board its passenger aircraft. Based on our own experience and considering the recent regulations of the European Joint Aviation Authority (JAA), the items are updated. The design of the kit is arranged so that all the medications with a short "kit life" are placed in a compartmented tray and can be removed in toto and replaced by a new tray. The equipment and medications in the MK are listed on the form which the physician on board is required to complete, checking the items used and filing a report. The contents of the MK will evidently be upgraded once ECG monitoring, transmission facilities and automatic external defibrillators (AED) are put on board.

Aerospace Medicine↗
PubMed2000

[Trends and estimates of regional differences of cornea donation and transplantation in France (1991-1998)].

PURPOSE: To evaluate national trends of corneal procurement and transplantation, and to estimate regional disparities between the rates of transplantation and patients registered on local waiting lists. METHODS: A questionnaire was sent, every year since 1994, to all the heads of ophthalmology departments in public and private hospitals. RESULTS: After a dramatic decrease in 1992, donations and transplantations then increased to reach 4549 and 4053 in 1998. This increase was mainly observed for cornea retrieval from non heart beating donors in public hospitals. Since 1997, the number of imported corneas has increased, 1016 corneas were imported in 1998 (25% of the corneas transplanted). The estimate of the number of patients registered on local waiting lists decreased to 7400 at the end of 1998. Regional agreement, using the ratio of the number of patients registered on waiting list at the end of 1998 and the number of cornea harvested in 1998 was low for several French regions: Aquitaine, Champagne-Ardenne, Nord-Pas-de-Calais, Picardie, Ile-de-France, Rhône-Alpes, Antilles. CONCLUSION: Careful thought and regional efforts pointed at non-heart beating donors should be applied to increase the level of corneal harvesting, and to reduce waiting lists in France to levels similar to those in other European countries. Recent issue of legal authorization of cornea banking and creation in october 1999 of a national waiting list should facilitate these efforts.

France↗
PubMed2000

[Graft safety and need satisfaction: searching for a crucial balance].

In 1998, 3,033 organs were transplanted and 3,186 stem cell and 4,053 cornea grafts were performed in France. Organ shortage varies for each organ but is particularly critical for kidneys. Given the physiological and therapeutic efficacy of grafting, an increase in organ procurement is likely to raise safety problems. This paper concerns donor-transmitted infections, mainly viral infections. Regulations on health risks express a social and cultural refusal to accept any hazard. This collective concern is however in opposition with the interests of individual patients who are likely to accept a greater risk for an obvious benefit. Although the assessment of the risk/benefit ratio is clearly different between organ and tissue transplantation, further thought needs to be given to the problem of acceptance of infectious risk in organ transplantation. In France, special exceptions are now legally authorized for specific situations. Infectious agents transmitted by grafting have not been largely reported, mainly because screening tests were not available. The number of transmitted infections is increasing with the expansion of transport facilities and with the various geographical origins of the population. In some cases, search for histocompatibility between relatives living in endemic areas introduces new risks, for example tropical diseases. Diagnosis is often made by serological or molecular biological tests which may be difficult to analyze depending on their specificity. Organ transplantation is often an emergency requiring rapid decision making, for the donor or the recipient. However, with a quality assurance process based on accepted guidelines, the appropriate answers to operational problems can be given rapidly. Patient satisfaction can be achieved only if the public health challenge is met. Increasing organ procurement can clearly be expected to be beneficial, but at the cost of higher risks. Nevertheless, benefit and risk are quite different, benefit is for the time being while risk is delayed and may be uncertain depending on individual survival. Because of the variability of human disease, especially in situations where an ultimate therapy is involved, automatic application of a standard procedure must be avoided as it would inevitable lead to a cut-back in organ procurement in an attempt to achieve a theoretically safe situation which would be contrary to individual patient's self-interest. Health care workers should have good knowledge of the epidemiology of these diseases in order to assess risk. The patient must be able to express informed consent.

France↗
PubMed2000

["Population and xenograft" investigation. Preliminary results].

The chronic shortage of human organs is the argument for xenotransplantation. In emergencies, acceptability is closely linked to the benefit. Little information is available on attitudes towards xenotransplantation. A poll of the attitudes was carried out, based on a questionnaire with targeted questions and background information. The goal of the study was to have a better understanding of people's attitudes towards xenotransplantation and to know the eventual changes in the answers after having been given information. For 75% of the sample, xenotransplantation would be a future biotechnology. The animal sources that would be considered for xenotransplantation were the pig and monkey. A period of ten years or more is necessary for 69% of the respondents before xenografts are performed routinely; for 19%, five years or less are needed. Human organ donation should be continued, according to 90% of the sample. Roughly, 46.4% support xenotransplantation, though in the case of a life-or-death situation acceptance reaches 65.7%. This level is higher (77%) for relatives or unknown people (71%); 74% of respondents were in favour of using normal animals and a large majority (88%) support research on xenotransplantation. A good level of confidence in medical biotechnology research and practice is suggested by this study, contrary to the results of a European survey on biotechnology.

Adult↗
PubMed2000

Adenovirus mediated cytosine deaminase gene transduction and 5-fluorocytosine therapy sensitizes mouse prostate cancer cells to irradiation.

PURPOSE: We assess the ability of adenovirus mediated expression of the Escherichia coli cytosine deaminase gene in conjunction with the prodrug 5-fluorocytosine to result in radiation sensitization in the mouse prostate cancer cell line RM-1 in vitro. MATERIALS AND METHODS: To document cytotoxicity of gene therapy, RM-1 cells were exposed to escalating doses of adenovirus mediated cytosine deaminase and a fixed dose of 5-fluorocytosine or phosphate buffered saline. Viable cells as determined by exclusion of trypan blue were counted the following day. Cytosine deaminase expressing RM-1 cells were then irradiated as single cell suspensions at various doses of radiation in a cesium source (4.4 Gy. per minute) and randomized to receive 5-fluorocytosine therapy at different times in relation to the external radiation therapy. End points were determined in a clonogenic assay by counting colonies with greater than 50 cells 7 days after replating. RESULTS: Use of adenovirus mediated cytosine deaminase plus 5-fluorocytosine demonstrated viral dose dependent killing of RM-1 cells to a maximum of 85%, while either therapy alone was nontoxic. Neither adenovirus mediated cytosine deaminase infection nor 5-fluorocytosine alone influenced external radiation therapy killing. However, after controlling for death due to gene therapy alone, the combination of adenovirus mediated cytosine deaminase plus 5-fluorocytosine and external radiation therapy resulted in synergistic activity to approximately 2 logs of cell kill at low doses of radiation (p = 0.001). While altering the chronology of prodrug exposure in relation to external radiation therapy maintained synergy in all scenarios tested, starting 5-fluorocytosine 24 hours before external radiation therapy resulted in the most profound killing (p = 0.04), which indicates the importance of maintaining prodrug therapy during external radiation therapy. CONCLUSIONS: The combination of adenovirus mediated cytosine deaminase plus 5-fluorocytosine and radiation therapy resulted in radiation sensitization with clinically relevant doses of radiation suggesting a potential usefulness of this treatment in patients with prostate cancer.

Adenoviridae↗