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H Ben-Hur

Publications and source records attributed to H Ben-Hur.

At least 73 records · Page 4Linked to original sources
PubMed1992

The importance of the endopelvic fascia repair during vaginal hysterectomy.

During 1985 to 1989, 177 vaginal hysterectomies were performed in the Department of Gynecology, Kaplan Hospital, Rehovot, Israel, using the Porges technique with some modifications. Ninety patients had some degree of loss of the pelvic support--anterior or posterior wall relaxation, enterocele or uterine prolapse in various degrees. The patients were allocated to two groups, in which two different techniques were compared: group 1, with repair of the pubocervical and pararectal fascia and group 2 without the repair. The repair of the pubocervical and pararectal fascia after vaginal hysterectomy prevented vaginal vault prolapse (zero versus 15 percent, p < 0.01) and reduced the incidence of recurrent rectocele (23 versus 55 percent, p < 0.05) and recurrent cystocele (14 versus 45 percent, p < 0.005). Recurrent genuine stress incontinence was found in 9 percent of patients in group 1 and 18 percent of patients in group 2 (not statistically significant; p = 0.163). Optimal management of relaxation of the vaginal wall during vaginal hysterectomy requires clinical suspicion and precise preoperative diagnosis and therapeutic plan. In the present study, the need for careful repair of the pubocervical and pararectal fascia during vaginal hysterectomy to prevent vaginal vault prolapse is emphasized. This procedure does not prolong the operation significantly (92 +/- 15 versus 84 +/- 17 minutes) and has no deleterious postoperative complications.

Aged↗
PubMed1991

Developmental pattern of muscarinic receptors in normal and Down's syndrome fetal brain--an autoradiographic study.

The ontogeny of muscarinic cholinergic receptors in developing human brain was analyzed by in vitro receptor autoradiography with [3H]Quinuclidinyl Benzilate. It was found that muscarinic receptors develop relatively early; the levels at 24 weeks of gestation were comparable or even higher then the values in the adult brain, and that the levels of both M1 and M2 receptors increase with age. M1 receptors were concentrated mainly in forebrain regions while M2 receptors dominated in the thalamus. Scatchard analysis revealed Kd and Bmax values which are comparable to the adult values. Three brains of aborted Down's syndrome fetuses were examined in parallel and exhibited comparable levels and similar distribution to normal non-Down fetuses except for a modest increase of receptor levels which was observed in the striatum.

Abortion, Induced↗
PubMed1991

Fetal human brain exhibits a prenatal peak in the density of serotonin 5-HT1A receptors.

High densities of serotonergic 5-HT1A receptors, in excess of adult levels, were found in the human fetal brain between the 16th and 22nd weeks of gestation, 5-HT1A receptors were measured by quantitative autoradiography using brain sections of fetuses aborted at gestational ages 16-22 weeks. The highest receptor concentrations were detected in the cortex and hippocampus. Two brains obtained from fetuses with Down's syndrome at 22 and 24 weeks gestation exhibited abnormal receptor levels compared to age matched controls. The presence of an early, prenatal peak of 5-HT1A receptors in fetal cortex and hippocampus suggests that these receptors play a role in human brain development and may also be involved in developmental disorders such as Down's syndrome.

Brain↗
PubMed1991

Transcription initiation in the two leader exons of the rat IGF-I gene occurs from disperse versus localized sites.

Rat IGF-I mRNAs contain two different 5'-UTR sequences as a result of alternate splicing of leader exons. Using a combination of solution hybridization/RNase protection and primer extension assays, we have mapped the transcriptional start sites in these leader exons. There appear to be three putative transcription start sites in exon 1 spread over a 140-bp region, the most upstream of which defines a 381 bp-long exon 1. There appear to be three distinct start sites in exon 2, the most upstream of which defines a greater than 770 bp-long exon 2. The two downstream start sites in exon 1 together account for approximately 70% of IGF-I gene expression in adult rat liver. Essentially all of the remaining IGF-I gene expression comes from the second start site in exon 2. Rat IGF-I gene transcription may therefore be regulated by two distinct promoter regions, a disperse promoter for exon 1, with several transcription initiation sites, and a more typical promoter region for exon 2, which controls transcription initiation from a discrete region.

Animals↗
PubMed1991

Regulation of start site usage in the leader exons of the rat insulin-like growth factor-I gene by development, fasting, and diabetes.

Rat insulin-like growth factor-I (IGF-I) mRNAs with different 5'-untranslated region/prepeptide coding sequences result from transcription initiation in one of two leader exons. While not altering the mature IGF-I coding sequence, these different leaders potentially encode two distinct IGF-I prepeptides, one of 48 amino acids (exon 1) and one of 32 amino acids (exon 2). Within exon 1, transcription initiation is dispersed (i.e. occurs over a approximately 350-basepair region), while within exon 2, it is highly localized. A fourth exon 1 start site, residing only approximately 30 basepairs from its 3' end, is suggested on the basis of RNase protection assays; its use would produce an mRNA encoding a third distinct IGF-I leader peptide of 22 amino acids. We have determined that during postnatal development, and as a result of insulinopenic diabetes and fasting, choice of transcription start sites within exon 1 in the liver is coordinately regulated, i.e. use of all start sites increased during development and decreased in the two catabolic states. Transcription initiation at the single major site within exon 2 was also reduced in diabetes and fasting. Insulin replacement therapy and refeeding restored the levels of all transcripts coordinately. During postnatal development, however, transcripts initiating within exon 2 exhibited a different developmental profile than did exon 1 transcripts, increasing especially at the onset of GH-dependent linear growth. In liver, therefore, negative regulation of exon 1 and exon 2 transcription start site usage occurs in catabolic states, while in development, differential regulation of exon 1 and exon 2 transcription start sites occurs.

Aging↗
PubMed1991

Dysplastic vulvar nevi.

Of several pigmented vulvar lesions, the dysplastic nevus, a know precursor of malignant melanoma, has been described only twice. Focusing on pigmented vulvar lesions, 18 were excised among approximately 500 unselected parturients. Three lesions showed clinical and histologic characteristics of a dysplastic nevus. The patients with a dysplastic vulvar nevus were 21, 27, and 30 years old, respectively; all three had multiple torso and limb nevi and two had anamnestic features of the dysplastic nevus syndrome. Only one was aware of her vulvar lesion. All dysplastic nevi were brown or black and were larger than 5 mm in diameter. Our cases suggest that dysplastic vulvar nevi may be more frequent than previously thought. We suggest that the puerperium is a suitable time for a definite histologic diagnosis of large-size lesions with variegated pigmentary patterns and irregular borders that occur on the vulvar skin. Likewise, in other patients with suspected dysplastic vulvar nevi, excisional biopsy is recommended.

Adult↗
PubMed1990

Immune modulation exerted by thymic humoral factor (THF-gamma 2), on T-cell subsets and IL-2 production of umbilical cord blood lymphocytes.

The effect of a synthetic thymic humoral factor, THF-gamma 2, on the immune competence of T-cells was investigated in vitro on lymphocytes from human cord blood (UCBL). It was found that preincubation of UCBL with THF-gamma 2 caused an increase in the percentage of cells expressing the CD4 or the CD8 differentiation antigens, but did not affect the percentage of CD3 cells. The effect of THF-gamma 2 on PHA-induced IL-2 secretion was also studied and found that a 3hr preincubation with THF-gamma 2, prior to suboptimal PHA stimulation caused an increase in the IL-2 activity of the treated UCBL cultures. This effect was THF-gamma 2 dose dependent with an optimum in the range of 300-600 ng/ml and was not influenced by irradiation of the UCBL. These results indicate that THF-gamma 2, a synthetic octapeptide, modulates the immune state and response of human umbilical cord blood lymphocytes.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1989

Postsecretory modifications of streptavidin.

Streptavidin, an extracellular biotin-binding protein from Streptomyces avidinii, exhibits a multiplicity in its electrophoretic mobility pattern which depends both upon the conditions for growth of the bacterium and upon the protocol used in the purification of the protein. The observed structural heterogeneity appears to reflect the action of two types of postsecretory molecular events: proteolytic digestion of the intact Mr-18,000 subunit to a minimal molecular size (approx. Mr 14,000), and aggregation of the native tetramer into higher-order oligomeric forms. The extent of subunit degradation and/or tetrameric aggregation affects the capacity of a given streptavidin preparation to interact with biotin-conjugated proteins in different assay systems.

Amino Acid Sequence↗
PubMed1989

Cytokeratin patterns in the epidermis of human ovarian mature cystic teratomas.

Using a battery of monoclonal antibodies, we investigated the cytokeratin pattern in the epidermides of 12 human ovarian mature cystic teratomas (MCTs) and compared them with those of infant, adult, and fetal skin. Histologically, two types of epidermal layers were identified in the MCTs, a mature layer and an immature layer. The mature layer was similar to the epidermis of infants and adults, while the immature layer resembled stratified nonkeratinizing and metaplastic squamous epithelium. The cytokeratin pattern of the histologically mature epidermis in MCT was either similar to that in infants and adults or was of the fetal type. The cytokeratin expression of the histologically immature epidermis in MCT also showed many similarities to the fetal cytokeratin pattern. We conclude that histologic maturity of the epidermis in MCT is not necessarily expressed by the cytokeratin pattern, which reflects the state of molecular rather than histologic differentiation. Since prognosis in germ cell tumors is usually related to the degree of tissue maturation, our observations raise the possibility that the cytokeratin profile may eventually prove to be a valuable prognostic tool in some of the neoplasms that contain epithelial elements.

Adult↗
PubMed1988

Biocytin hydrazide--a selective label for sialic acids, galactose, and other sugars in glycoconjugates using avidin-biotin technology.

Biocytin hydrazide (BCHZ), a new, water-soluble, long-chained, biotin-containing hydrazide, was synthesized and used for the selective nonradioactive detection of glycoconjugates. Procedures were developed for labeling glycoconjugates on blots. The method involves either chemical (periodate-induced) or enzymatic (via galactose oxidase) oxidation of glycoconjugates, the resultant aldehyde groups are then labeled with biocytin hydrazide, followed by interaction with an avidin-based enzyme probe. Since the biotin-containing reagent is a relatively small, charged molecule, the primary labeling step may be carried out on intact cells and on membrane preparations as well as on blotted samples. On blots, the labeling pattern was similar for both periodate- and galactose oxidase-induced biotinylation procedures. In contrast, periodate-induced labeling of either erythrocyte membranes or cells (prior to blotting) produced an altered labeling pattern. Combined enzyme-induced biotinylation of membranes or cells resulted in a pattern similar to that observed for the direct staining of blots. Using galactose oxidase on human erythrocyte membranes, the procedure was sensitive enough to selectively label the Band 3 lactosaminoglycoprotein.

Avidin↗
PubMed1987

Enzyme-based detection of glycoproteins on blot transfers using avidin-biotin technology.

Avidin-biotin technology has been employed for the improved nonradioactive detection of glycoproteins on blots. Periodate oxidation of samples on blots converts the glycoprotein-based carbohydrate residues to the corresponding aldehydes. The latter undergo interaction with preformed complexes consisting of either avidin hydrazide or streptavidin hydrazide combined with biotinylated alkaline phosphatase. The sensitivity of the new assay exceeds the previously described enzyme hydrazide method by a factor of at least 10. The approach can be rendered selective for sialoglycoproteins, and approximately 12 sugar-containing bands could be observed in erythrocyte membrane preparations. Problems of nonspecific binding and high levels of background label were alleviated using a nonglycosylated basic protein (lysozyme) for quenching.

Alkaline Phosphatase↗
PubMed1986

p-Diazobenzoyl biocytin--a new biotinylating reagent for the labeling of tyrosines and histidines in proteins.

A new biotin-containing reagent, p-diazobenzoyl biocytin (DBB), has been developed for labeling tyrosines and histidines in proteins. The reagent has used to label these residues in both model proteins and erythrocyte membrane proteins on dot blots and blot transfers. In some cases, sub-nanogram levels of individual proteins could be detected. The utility of DBB as a versatile alternative to biotin-containing N-hydroxysuccinimide esters for the general labeling of proteins is discussed.

Animals↗