Biomedical subjects

A Sharon

Publications and source records attributed to A Sharon.

At least 19 recordsLinked to original sources

PubMed2003

PF-IND: probability algorithm and software for separation of plant and fungal sequences.

The separation of plant and fungal sequences in EST pools by bioinformatic methods is difficult because of sequence similarities between plants and fungi, lack of enough sequence information, and the short length of the isolated fragments. An algorithm and software that utilize the differences in codon usage bias to discriminate between plant and fungal sequences are described. The software (PF-IND) includes five pairs of fungi and their host plants that can be used to analyze a large number of related species. Analysis of a sequence provides an arbitrary value that defines the likelihood that a sequence will be a fungal or a plant gene. The software can distinguish between homologous fungal and plant genes and it helps identify the correct reading frame of unknown expressed sequence tags (ESTs) for which BLAST analyses do not provide clear information. Short sequences of 100-150 bp can be analyzed with high confidence. PF-IND analysis of 100 sequences derived from fungal infected plants identified the origin of 94 sequences. Only 66 sequences were identified by a BLASTX analysis of the same 100 ESTs. Overall, PF-IND is a novel bioinformatic tool aimed at assisting the research of fungus-plant interactions.

Algorithms↗

PubMed2001

Endometrial ablation for the postmenopausal woman.

The postmenopausal woman with abnormal uterine bleeding is considered at risk for developing endometrial neoplasia or one of its precursors. She requires prompt evaluation of the endometrium followed by adequate treatment. In the subgroup of postmenopausal women taking hormone replacement therapy (HRT), the risk of abnormal bleeding is by far higher, is the main reason for discontinuing HRT, and deserves additional attention.

Aged↗

PubMed2000

High-dose intravenous isosorbide-dinitrate is safer and better than Bi-PAP ventilation combined with conventional treatment for severe pulmonary edema.

OBJECTIVE: To determine the feasibility, safety and efficacy of bilevel positive airway ventilation (BiPAP) in the treatment of severe pulmonary edema compared to high dose nitrate therapy. BACKGROUND: Although noninvasive ventilation is increasingly used in the treatment of pulmonary edema, its efficacy has not been compared prospectively with newer treatment modalities. METHODS: We enrolled 40 consecutive patients with severe pulmonary edema (oxygen saturation <90% on room air prior to treatment). All patients received oxygen at a rate of 10 liter/min, intravenous (IV) furosemide 80 mg and IV morphine 3 mg. Thereafter patients were randomly allocated to receive 1) repeated boluses of IV isosorbide-dinitrate (ISDN) 4 mg every 4 min (n = 20), and 2) BiPAP ventilation and standard dose nitrate therapy (n = 20). Treatment was administered until oxygen saturation increased above 96% or systolic blood pressure decreased to below 110 mm Hg or by more than 30%. Patients whose conditions deteriorated despite therapy were intubated and mechanically ventilated. All treatment was delivered by mobile intensive care units prior to hospital arrival. RESULTS: Patients treated by BiPAP had significantly more adverse events. Two BiPAP treated patients died versus zero in the high dose ISDN group. Sixteen BiPAP treated patients (80%) required intubation and mechanical ventilation compared to four (20%) in the high dose ISDN group (p = 0.0004). Myocardial infarction (MI) occurred in 11 (55%) and 2 (10%) patients, respectively (p = 0.006). The combined primary end point (death, mechanical ventilation or MI) was observed in 17 (85%) versus 5 (25%) patients, respectively (p = 0.0003). After 1 h of treatment, oxygen saturation increased to 96 +/- 4% in the high dose ISDN group as compared to 89 +/- 7% in the BiPAP group (p = 0.017). Due to the significant deterioration observed in patients enrolled in the BiPAP arm, the study was prematurely terminated by the safety committee. CONCLUSIONS: High dose ISDN is safer and better than BiPAP ventilation combined with conventional therapy in patients with severe pulmonary edema.

Dose-Response Relationship, Drug↗

PubMed2000

Telomerase activity in HPV-associated vulvar vestibulitis.

OBJECTIVE: To find a possible correlation between telomerase activity, mean telomere length and human papillomavirus (HPV) presence and type in vulvar vestibulitis. STUDY DESIGN: Twenty-two tissues excised during surgery for the treatment of severe vulvar vestibulitis and nine control tissue samples were tested for telomerase activity, mean telomere length, and HPV presence and type. RESULTS: Thirty-six percent of the tissues from vestibulitis patients were infected with HPV, mainly type 16/18, and none of the control tissue samples showed presence of HPV DNA (P < .02). Telomerase activity was detected in all tissues harboring HPV DNA, whereas only 64% of tissues without HPV DNA exhibited telomerase activity (P < .02). The mean telomere length was unchanged as compared to control samples. CONCLUSION: Telomerase activity in vestibulitis may be increased as a result of HPV infection, suggesting that HPV infection may play a role in the etiology of some cases of vulvar vestibulitis.

Adult↗

PubMed1999

A mitogen-activated protein kinase of the corn leaf pathogen Cochliobolus heterostrophus is involved in conidiation, appressorium formation, and pathogenicity: diverse roles for mitogen-activated protein kinase homologs in foliar pathogens.

Fungal pathogens perceive and respond to molecules from the plant, triggering pathogenic development. Transduction of these signals may use heterotrimeric G proteins, and it is thought that protein phosphorylation cascades are also important. We have isolated a mitogen-activated protein kinase homolog from the corn pathogen Cochliobolus heterostrophus to test its role as a component of the transduction pathways. The new gene, CHK1, has a deduced amino acid sequence 90% identical to Pmk1 of the rice blast fungus Magnaporthe grisea and 59% identical to Fus3 of Saccharomyces cerevisiae. A series of chk1 deletion mutants has poorly developed aerial hyphae, autolysis, and no conidia. No pseudothecia are formed when a cross between two Deltachk1 mutants is attempted. The ability of Deltachk1 mutants to infect corn plants is reduced severely. The growth pattern of hyphae on a glass surface is strikingly altered from that of the wild type, forming coils or loops, but no appressoria. This set of phenotypes overlaps only partially with that of pmk1 mutants, the homologous gene of the rice blast fungus. In particular, sexual and asexual sporulation both require Chk1 function in Cochliobolus heterostrophus, in contrast to Pmk1, but perhaps more similar to yeast, where Fus3 transmits the mating signal. Chk1 is required for efficient colonization of leaf tissue, which can be compared with filamentous invasive growth of yeast, modulated through another closely related mitogen-activated protein kinase, Kss1. Ubiquitous signaling elements thus are used in diverse ways in different plant pathogens, perhaps the result of coevolution of the transducers and their targets.

Amino Acid Sequence↗

PubMed1999

[Acute, painful, swollen testis in polyarteritis nodosa: a diagnostic problem].

An acutely painful and swollen testis mandates urgent diagnostic and therapeutic measures since this symptom complex may indicate torsion of the testis. Prompt scrotal exploration is necessary if the testis is to be saved from ischemic necrosis. Polyarteritis nodosa (PAN) is a vasculitis involving mainly medium and small sized arteries and may damage any organ. In PAN, the presentation of an acutely painful and swollen testis raises a perplexing diagnostic problem since the symptoms may be related to vasculitis involving the testis on the one hand, or represent primary testicular pathology unrelated to the underlying PAN. A 31-year-old man with PAN who presented with acute pain and swelling in a solitary testis is reported.

Adult↗

PubMed1999

A G protein alpha subunit from Cochliobolus heterostrophus involved in mating and appressorium formation.

A Galpha subunit-encoding gene (CGA1) was cloned from Cochliobolus heterostrophus, a heterothallic foliar pathogen of corn. The deduced amino acid sequence showed similarity to Galpha proteins from other filamentous fungi and suggested that CGA1 is a member of the Galphai class. cga1 mutants had reduced ability to form appressoria on glass surfaces and on corn leaves; mutants nevertheless caused lesions on corn plants like those of wild type. cga1 mutants were female sterile; sexual development was completely abolished when the mutant allele was homozygous in a cross. Ascospores produced in crosses heterozygous at Cga1 were all wild type. The signal transduction pathway represented by CGA1 appears to be involved in developmental pathways leading to either appressorium formation or mating; in sexual development CGA1 is required for both fertility and ascospore viability.

Amino Acid Sequence↗

PubMed1999

Transformation of the bioherbicide Colletotrichum gloeosporioides f. sp. Aeschynomene By electroporation of germinated conidia.

A highly efficient and reproducible procedure for the transformation of the bioherbicide Colletotrichum gloeosporioides f. sp. aeschynomene by electroporation of germinated conidia is reported. Development of the procedure involved a detailed study of the germination process followed by extensive calibration of the electrical-pulse and selection conditions. Optimization of the transformation protocol was facilitated by the use of the green fluorescent protein that helped in the identification of stable transformants and in a fast assessment of transgene expression levels, colony homogeneity and genetic stability. Under optimal conditions, over 80 stable transformants/cuvette were obtained. Plasmid integration was predominantly homologous, but high transformation rates were obtained both with homologous and non-homologous vectors. The method described not only opens up opportunities for the genetic manipulation of C. gloeosporioides f. sp. aeschynomene, but also provides a framework for the development and optimization of transformation in other fungi.

Calibration↗

PubMed1999

Polymorphism for mutation of cytosine to thymine at location 677 in the methylenetetrahydrofolate reductase gene is associated with recurrent early fetal loss.

OBJECTIVE: This study was undertaken to determine whether a cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase is associated with particular subtypes of recurrent unexplained spontaneous abortion. STUDY DESIGN: The prevalences of cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase among 41 patients with recurrent unexplained spontaneous abortions and among 18 healthy control subjects were determined with polymerase chain reaction. RESULTS: Homozygosity and heterozygosity for the cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase were observed at nonsignificantly different rates among patients and control subjects (9% and 48% versus 22% and 38%, respectively, P <.95). Among patients with recurrent unexplained spontaneous abortions both homozygosity and heterozygosity were associated with significantly increased prevalence of recurrent early fetal loss rather than with repeated anembryonic gestations (P <.0001). CONCLUSION: The observation that polymorphism for the cytosine to thymine mutation at nucleotide 677 in the gene encoding for methylenetetrahydrofolate reductase is associated with repeated early fetal losses rather than with anembryonic gestations strengthens the argument for the role of hypercoagulability and abnormal uteroplacental vasculature in recurrent spontaneous abortion.

Abortion, Habitual↗

PubMed1999

Immediate versus delayed treatment of perimenopausal bleeding due to benign causes by balloon thermal ablation.

STUDY OBJECTIVE: To compare the effectiveness and safety of thermal balloon ablation without pretreatment with endometrium-thinning agents compared with delayed ablation with pretreatment for women with perimenopausal menorrhagia. DESIGN: Prospective, randomized, controlled trial (Canadian Task Force classification I). SETTING: Hospital-based ambulatory medical center. PATIENTS: Thirty women age 46 to 51 years with severe enough perimenopausal menorrhagia to make them candidates for either hysterectomy or endometrial ablation. Two patients with submucosal myomas and six who had undergone cesarean section were included. INTERVENTIONS: Thirteen patients were randomly assigned to be treated within 30 days and received a single intramuscular administration of gonadotropin releasing hormone (GnRH) analog; 17 women were allocated to be treated within 3 days of enrollment without uterine preparation. A thermal balloon was inserted transcervically under general anesthesia, and after inflation in the endometrial cavity with 5% dextrose in water, was heated to 87 degrees C for 8 minutes. MEASUREMENTS AND MAIN RESULTS: Immediate and long-term major and minor complications and success rates were analyzed. Bleeding patterns and mean duration of menstrual flow were compared between groups at 6-month follow-up. No major intraoperative or postoperative complications occurred in either group, including the women who had recently undergone hysteroscopic myomectomy or had a history of cesarean section. Minor side effects were similar in both groups, and did not exceed 5%. Overall, at 6-month follow-up, 7 women were amenorrheic, 20 hypomenorrheic, and 3 eumenorrheic. No significant differences were noted between women treated with immediate or delayed ablation in either the distribution of bleeding patterns or days of flow per cycle (mean +/- SEM 1.8 +/- 0.42 vs 2.1 +/- 0.75 days, respectively). CONCLUSION: This pilot study suggests that prompt treatment of perimenopausal menorrhagia with thermal balloon endometrial ablation is as effective and safe as deferred therapy combined with GnRH analog as an endometrium-thinning agent. In light of our results, the theory that previous cesarean section and presence of small submucosal myomas constitute relative contraindications for the procedure merits further consideration. (J Am Assoc Gynecol Laparosc 6(2):145-150, 1999)

Catheter Ablation↗

PubMed1999

Increased telomerase activity and decreased telomere length in genital condylomata acuminata.

Our objective was to find a possible correlation between telomerase activity, mean telomere length and human papillomavirus (HPV) presence and type in genital condylomata acuminata. Fifteen biopsies from women with genital condylomata acuminata and nine control tissue samples were tested for telomerase activity, mean telomere length, and HPV presence and type. All condylomata exhibited telomerase activity, compared to 78% of the control samples. The mean telomere length of condylomata was significantly (P<0.002) shorter compared to telomere length in control tissue samples. All condylomata lesions were infected with HPV types 6/11, and more than half had additional infection with HPV 16/18. Mixed HPV 6/11 with 16/18 infection correlated with shorter telomeres than presence of HPV 6/11 alone in the lesions (4.68 +/- 0.44 kb vs 4.97 +/- 0.57 kb). None of the control tissue samples showed presence of HPV DNA. Telomerase activity may be a marker of proliferation rather than malignancy, whereas the mean telomere length could better serve as a marker for the progression of HPV lesions toward malignancy.

Biopsy↗

PubMed1999

Pelvic actinomycosis. Is long-term antibiotic therapy necessary?

OBJECTIVE: To describe 11 cases of actinomycosis and analyze whether long-term antibiotic use in necessary. STUDY DESIGN: Analysis of 11 cases of pelvic actinomycosis diagnosed and treated during the last nine years. Four patients had an intrauterine device (IUD) for 6-20 years, three patients had an IUD for 3-5 years, and four patients had no known etiology. In most patients the symptoms lasted from several days to one month. The actinomycotic lesions involved one or both ovaries in all 11 cases. In five patients the lesion extended to other areas, such as the uterus, omentum, parametrium, pelvic walls, colon, bladder, cul-de-sac and gallbladder. RESULTS: All patients underwent surgery that included removal of the lesions with the ipsilateral or both adnexa and, in specific cases, with extension of the lesions, hysterectomy, omentectomy, hemicolectomy and cholecystectomy. Confirmation of the diagnosis of actinomycosis was done by histology in all cases, and antibiotic treatment usually began 1-14 days after surgery. The drug of choice was penicillin. The duration of treatment was 12 months in 6 patients, 6 months in 3 and < or = 3 months in two. All patients were alive and well after two to nine years of follow-up. CONCLUSION: In contrast to actinomycosis at other sites, where the literature recommends antibiotic therapy for 6-12 months, pelvic actinomycosis could be a limited disease. We propose that in cases of pelvic actinomycosis where the abscess can be completely removed surgically, a shorter period of antibiotic therapy can be effective.

Actinomycosis↗

PubMed1998

Indole-3-acetic acid biosynthesis in colletotrichum gloeosporioides f. sp. aeschynomene

We characterized the biosynthesis of indole-3-acetic acid by the mycoherbicide Colletotrichum gloeosporioides f. sp. aeschynomene. Auxin production was tryptophan dependent. Compounds from the indole-3-acetamide and indole-3-pyruvic acid pathways were detected in culture filtrates. Feeding experiments and in vitro assay confirmed the presence of both pathways. Indole-3-acetamide was the major pathway utilized by the fungus to produce indole-3-acetic acid in culture.

Journal Article↗

PubMed1996

An asexual fungus has the potential for sexual development.

The availability of cloned genes that control sexual reproduction (mating type genes) in high fungi has allowed us to consider the causes of failure to mate in asexual fungi. We report here that the asexual fungus Bipolaris sacchari has a homolog of the MAT-2 gene of its sexual ascomycete relative Cochliobolus heterostrophus. The B. sacchari MAT-2 sequence is highly similar to that of C. heterostrophus MAT-2 and, in fact, functions in transgenic C. heterostrophus. Thus, the asexual nature of B. sacchari is not due to absence or mutation of MAT. When either of the C. heterostrophus MAT genes was transformed into B. sacchari, the recipient could neither self nor cross with other B. sacchari strains, in contrast to transgenic C. heterostrophus strains which can do both. Persistent asexuality of B. sacchari, in spite of the presence of complementary functional MAT genes, suggests that this fungus lacks genes other than MAT which are essential for mating. Notably, the transgenic B. sacchari strains were sometimes able to initiate, but not complete, sexual development in interspecific pairings with C. heterostrophus. Transcript analysis showed that the B. sacchari MAT-2 gene is expressed in transgenic C. heterostrophus and that the C. heterostrophus MAT genes are expressed in transgenic B. sacchari. No transcript of the native B. sacchari MAT-2 gene was detected under any growth condition tested.

Amino Acid Sequence↗

PubMed1994

Physician use of a computerized medical record system during the patient encounter: a descriptive study.

The computerized medical record program, CLINIC, specifically designed at Ben-Gurion University of the Negev to be used on-line in a primary care clinic during a patient encounter by healthcare professionals, has been in use for over 6 years in two community clinics. In order to analyse the effectiveness and use of CLINIC, four physicians were video recorded during working sessions before and after the introduction of CLINIC. While using CLINIC did not change the total mean encounter time, the lengths of the encounter components and record use did change. The physicians' work style changed from a 'conversational pattern' (continuous data recording) to a 'blocked pattern' (data entry at intervals).

Attitude of Health Personnel↗

PubMed1993

Effect of catalytically active recruited crystallins on lens metabolism.

The impact on duck lens metabolism of recruited epsilon-crystallin/LDH-B4 and tau-crystallin/enolase was investigated by NMR spectroscopy. A comparison of the duck lens metabolite profile with that of the calf in which recruited crystallins are absent revealed significant increases in ATP, alpha-glycerophosphate (alpha-GP) and pyridine dinucleotide concentrations. The alterations in the concentrations of ATP and alpha-GP appear to be related to both the high concentration of NAD and the elevated reduced to oxidized NADH/NAD+ ratio.

Adenosine Triphosphate↗

PubMed1993

Hereditary angioneurotic edema with severe hypovolemic shock.

Hereditary angioneurotic edema (HAE) is characterized by recurrent attacks of edema of the upper airways, face, and limbs, and/or abdominal pains sometimes mimicking surgical abdomen. Our patient, a 24-year-old woman, had undergone laparotomy on a previous attack, at which a large amount of serious peritoneal fluid and edema of the intestinal wall were found. This time she presented with severe abdominal pain and profound hypovolemic shock requiring replacement of great amounts of fluids in addition to fresh frozen plasma. There was no evidence of bleeding, and the patient recovered rapidly. Based on clinical and ultrasonographic grounds and findings on previous laparotomy, we concluded that the shock was produced by fluid sequestration in the peritoneal cavity and intestinal wall. We propose that patients with HAE who present with abdominal pain, hypotension, hemoconcentration, and leukocytosis form a distinct subgroup with a high risk of hypovolemic shock. This dangerous development should be anticipated in these patients.

Abdomen, Acute↗

PubMed1992

Characteristics of ethylene biosynthesis-inducing xylanase movement in tobacco leaves.

(125)I-Labeled ethylene biosynthesis-inducing xylanase (EIX) was used to study the movement of this protein in tobacco (Nicotiana tabacum) tissues. A biologically active (125)I-labeled EIX was obtained using chloramine-T as the oxidizing agent. Labeled EIX was detected in the far most edges of the leaf 5 min after it was applied to the petiole of a detached leaf. EIX was distributed uniformly throughout the leaf, including the mesophyll area within 5 to 15 min, after which there was only little change in the distribution of radioactivity in the leaf. (125)I-Labeled EIX was extracted from treated leaves, and EIX translocation in the leaf was blocked by preincubation of labeled EIX with anti-EIX antibodies, indicating that the intact peptide moves in the leaf. Injection of anti-EIX antibodies into the intercellular spaces of the leaf mesophyll prevented induction of necrosis by EIX, suggesting the mesophyll as the site of EIX action. EIX was translocated both to upper and lower parts of the plant when applied to a whole plant through the petiole of a cut leaf. Radioactivity was found in all leaves and in the stem, although some leaves accumulated much more EIX than others; EIX was not found in the roots. There was no difference between the accumulation pattern of EIX in fresh and ethylene-treated leaves or between sensitive (Xanthi) and insensitive (Hicks) tobacco cultivars. These data support the hypothesis that intact EIX protein is translocated to the leaf mesophyll, where it directly elicits plant defense responses.

Journal Article↗