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J Wolff

Publications and source records attributed to J Wolff.

At least 91 records · Page 5Linked to original sources
PubMed1996

Insulin-like growth factor I receptor messenger expression during oogenesis in Xenopus laevis.

To study Xenopus insulin-like growth factor I (IGF-I) receptor messenger expression during oogenesis, we isolated a complementary DNA (cDNA) corresponding to the beta-subunit of the receptor. There is a high degree of conservation between the deduced polypeptide and the three mammalian sequences previously described for the IGF-I receptor (75% homology) even though it is lower than the homology among mammals themselves (95% homology). IGF-I receptor messenger RNAs were specifically detected by reverse transcription-PCR in oocytes, embryos, and adult liver and muscle. By in situ hybridization, these messenger RNAs could be visualized only in oocytes. Quantification showed that they accumulated from the previtellogenic stage until early vitellogenesis. No specific labeling could be detected in oocytes after stage IV of vitellogenesis. Thus, the IGF-I receptor messenger stock does not seem to increase further beyond this point or may even decrease. The long 3'-untranslated sequence (1.8 kilobases) included in the cDNA presents no homology with those of mammalian receptor cDNAs and could be longer, as no polyadenylated tail is observed. Some motifs corresponding to sequence described as cytoplasmic polyadenylation element or that have been described in unstable messengers could be observed. Moreover, a deadenylation of this RNA occurs in the postvitellogenic stage. These results suggest that translation occurred very early during oogenesis. Therefore, IGF-I receptor could play a role early on, during oocyte growth, in addition to its involvement in the maturation process.

Aging↗
PubMed1995

Colchicine binding by the "isolated" beta-monomer of tubulin.

At mole ratios of lactoperoxidase to tubulin monomers of 3-4, bovine lactoperoxidase forms 1:1 adducts with both alpha- and beta-tubulin from rat brain, thereby separating the tubulin heterodimer into its monomers. This mixture binds colchicine normally, and we show here by direct photoaffinity labeling that the bulk of the [3H]colchicine becomes attached to beta-tubulin under these conditions. When the alpha-tubulin has been displaced by lactoperoxidase, the ratio of label in beta-tubulin to alpha-tubulin is increased. The amount of label in alpha-tubulin decreases with a corresponding appearance of label in lactoperoxidase. The rate of labeling of beta-tubulin remains slow. We conclude that alpha-tubulin is not necessary for colchicine binding and propose a model wherein the A and C rings of colchicine bind to beta-tubulin, while the B ring faces alpha-tubulin in the dimer.

Animals↗
PubMed1995

Perilipins are associated with cholesteryl ester droplets in steroidogenic adrenal cortical and Leydig cells.

Steroidogenic cells store cholesteryl esters, precursors for steroid hormone synthesis, in intracellular lipid droplets. Cholesteryl ester hydrolysis is activated by protein kinase A and catalyzed by cholesteryl esterase. The esterase is similar, if not identical, to hormone-sensitive lipase in adipocytes where an analogous lipolytic mechanism occurs. Perilipins, proteins located exclusively at lipid droplet surfaces in adipocytes, are polyphosphorylated by protein kinase A in response to lipolytic stimuli, suggesting a role for these proteins in mediating lipid metabolism. The present study reveals that perilipins are associated with cholesteryl ester droplets in two steroidogenic cell lines: Y-1 adrenal cortical cells and MA-10 Leydig cells. The relative abundance of perilipin mRNAs and protein is much less in steroidogenic cells than in adipocytes. Like adipocytes, steroidogenic cells express perilipin A; additionally, the latter cells contain relatively abundant amounts of perilipin C, a protein that is not detectable in adipocytes by Western analysis. The data suggest a strong link between perilipins and lipid hydrolysis that is mediated by the hormone-sensitive lipase/cholesteryl esterase class of enzymes.

3T3 Cells↗
PubMed1995

Visual laser ablation of the prostate (VLAP): an effective alternative treatment of benign prostatic hyperplasia.

A total of 75 patients suffering from benign prostatic hyperplasia (BHP) were treated with visual laser ablation of the prostate (VLAP) using the Nd-Yag laser. Preoperative evaluation consisted in determination of urinary flow and residual urine, assessment of voiding symptoms and urodynamic evaluation. Postoperatively, the same evaluation was performed at 3 and at 6 months. VLAP is a relatively simple technique with a low perioperative morbidity and short time results are comparable to classical transurethral resection of the prostate. Therefore VLAP seems to be an effective alternative treatment method for BPH which may replace classical transureteral resection of the prostate in a selected number of cases.

Aged↗
PubMed1995

[The history of medical nursing schools at the Vienna University (1812 to 1846) and at the Royal Charité Hospital in Berlin since 1832].

The first examples of nurse training, beginning in Vienna in 1812 and in Berlin in 1832, demonstrate that research in nursing-history must explore primary sources which are still in existence, in order to counteract current cliche and perhaps even develop completely new insights into historical accounts. Nursing literature in Austria did not start will the textbook by Billroth (1st edition 1881), but with the textbook by Maximilian Florian Schmidt, same publisher, 50 years earlier. His professorship was not held in the University but in what would not be a technical school. The textbook by Schmidt, and not that by Franz Anton Mai (1782), provided the submission for the curriculum which Dieffenbach made available to the school opened in Berlin in 1832. Dieffenbach was given the title of "Professor" for his services to "the improvement of nursing" and not for his pioneer work in plastic and orthopedic surgery. It was not Dieffenbach's curriculum but the 1837 revision of the work of Gedike, who was not a pupil of Dieffenbach's, which was used by the ministery responsible for the Board of Trustees of the hospital, for the state controlled course of nursing education. This educational programme was not less optional than that statutorily controlled one from 1907 onwards.

Austria↗
PubMed1994

Local unfolding and the stepwise loss of the functional properties of tubulin.

Tubulin exhibits a number of characteristic functions that can be used to identify it. They include the ability to polymerize to microtubules, GTPase activity, and the binding of numerous antimitotic drugs and fluorophores. These functions can be differentially modified by low (0.1-1.0M) urea concentrations, and such urea-induced modifications are stable over time periods of minutes to hours. These intermediate states suggest the existence of restricted regions in the protein each of which is associated with a function and its own urea sensitivity. In order of decreasing sensitivity to urea these effects are decreased rate of polymerization of tubulin to microtubules > decreased extent of polymerization approximately decreased GTPase activity > enhanced fluorescence of a rapidly binding analogue of colchicine-MTPT [2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone] approximately decreased proteolysis by trypsin (after alpha Arg339) and by chymotrypsin (after beta Tyr281) > enhanced fluorescence of 1-anilino-8-naphthalenesulfonic acid (ANS). Additional evidence for the independent behavior of the restricted regions stems from the markedly different time dependence of the response to urea. These low urea concentrations do not induce significant changes in tryptophan fluorescence, suggesting that the observed effects are due to local unfolding. At higher urea concentrations (2-4 M), the enhanced fluorescence of the ligands is abolished; MTPT fluorescence decreases at lower urea concentrations than ANS fluorescence. Moreover, tubulin becomes highly susceptible to proteolysis at multiple sites, and tryptophan emission shows a red-shift, as expected. Multistep unfolding in response to denaturants has been reported for some other proteins. Tubulin appears to be an extreme example of such local responses that proceed under milder conditions than the global transition to the unfolded state.

Anilino Naphthalenesulfonates↗
PubMed1994

Induction of specific tolerance by intrathymic injection of recipient muscle cells transfected with donor class I major histocompatibility complex.

Induction of tolerance to allogeneic MHC antigens has been a goal in the field of transplantation because it would reduce or eliminate the need for generalized immunosuppression. Although encouraging results have been obtained in experimental models by exposing recipient thymus to donor cells before transplantation, donor cells are not typically available at that time, and the donor antigens responsible for the effect are poorly defined. In the present study, thymic tolerance was demonstrated without using donor cells. Recipient thymus was injected before transplantation with autologous myoblasts and myotubes that were genetically modified to express allogeneic donor-type MHC class I antigen. Donor-specific unresponsiveness was induced to a completely MHC-disparate liver transplant and to a subsequent donor-type cardiac allograft, but not a third-party allograft. In vitro, recipient CTL demonstrated a 10-fold reduction in killing of donor cells, but not of third-party cells. Our results demonstrate: (1) that recipient muscle cells can be genetically engineered to induce donor-specific unresponsiveness when given intrathymically, and (2) transfected recipient cells expressing only donor MHC class I antigen can induce tolerance to a fully allogeneic donor.

Animals↗
PubMed1994

Anabolic effect of human growth hormone: management of inherited disorders of catabolic pathways.

The effects of growth hormone treatment and dietary alanine supplementation, individually and in combination, were studied in five patients with organic acidemias. Three patients had propionic acidemia, one had 3-hydroxyisobutyric acidemia, and one had a defect in isoleucine metabolism. Two patients with propionic acidemia had decreased growth hormone secretion in response to provocative stimuli (intravenous L-arginine and oral levodopa or clonidine); the remaining subjects had sufficient growth hormone secretion. Three of four subjects in whom IGF1 was measured showed subnormal concentrations at baseline (including two with normal growth hormone secretory responses). All patients showed an increase in linear growth with growth hormone. In the four patients studied, all had a significant increase in nitrogen retention over baseline with alanine or growth hormone alone, or with the combination of growth hormone and alanine, with a much greater effect of growth hormone. Lean body mass and body fat composition tended to become normal with treatment. Protein tolerance increased, and when the patients' dietary protein intakes were increased between 20 and 60% they maintained positive nitrogen balance, without a significant increase in metabolite excretion. One patient with propionic acidemia expired during the time of the study, following a course of recurrent pancreatitis and an episode of acute basal ganglia infarction. All of the other subjects showed clinical improvement (decreased incidence of ketoacidotic episodes and decreased frequency of hospital admission and school absence) during treatment, and even the patient who expired remained metabolically stable up to and through the terminal event. We conclude that growth hormone may be of value in the management of patients with organic acidemia.

3-Hydroxybutyric Acid↗
PubMed1994

Biochemical and molecular studies of 132 patients with galactosemia.

We evaluated 132 galactosemia patients for the Q188R (glutamine-188 to arginine) mutation in the human galactose-1-phosphate uridyltransferase (GALT) gene and for GALT activity in their hemolysates by a sensitive radioisotopic method. In those without any detectable GALT activity (GG), the Q188R mutation constituted 67% of the alleles. In patients with detectable GALT activity (GV), only 16% of the alleles were accounted for by Q188R. In all patients who were homozygous for the Q188R mutation, no erythrocyte GALT activity could be demonstrated. There was an extensive variation in the amount of detectable GALT activity ranging from 0.1% to 5% of the normal values among the GV patients. There was a difference in the frequency of Q188R mutation in the GALT alleles among patients belonging to different racial and ethnic groups. In Caucasian and Hispanic patients, the frequency was not far different (64% and 58%, respectively). On the other hand, only 12% of the GALT alleles with Q188R were found in African-American patients.

Adolescent↗
PubMed1994

Effects of eltanolone on cerebral blood flow and metabolism in healthy volunteers.

BACKGROUND: Eltanolone is a new steroid anesthetic agent that may prove to be useful in clinical practice. The aim of the present study was to evaluate the effects of eltanolone on cerebral blood flow (CBF) and metabolism in healthy volunteers. METHODS: In a randomized cross-over study, eight subjects received intravenous eltanolone 0.6 mg/kg or its vehicle. CBF was measured with the intravenous xenon 133 technique before and 2 and 30 min after administration of eltanolone or vehicle. Cerebral metabolic rate for oxygen (CMRO2) was calculated as the product of the measured cerebral arteriovenous oxygen content difference and the blood flow. RESULTS: CBF decreased from a baseline value of 64 +/- 4 (mean +/- SD) to 42 +/- 6 ml.100 g-1.min-1 at 2 min after administration of eltanolone and only 4% after vehicle. Cerebral oxygen consumption was 4.1 +/- 0.4 ml.100 g-1.min-1 at baseline and decreased to 2.7 +/- 0.6 at 2 min after eltanolone, whereas metabolism did not change significantly after administration of vehicle. At 30 min CBF and Cerebral metabolic rate for oxygen were 16 and 10% less than baseline values, respectively. Coupling between CBF and Cerebral metabolic rate for oxygen was preserved at all measurements. After administration of eltanolone a significant decrease in mean arterial blood pressure of 6 mmHg and a period of hypoventilation were observed. This did not occur after injection of vehicle. CONCLUSIONS: Eltanolone was shown to reduce cerebral oxygen consumption and blood flow in healthy volunteers. Coupling between metabolism and flow was preserved.

Adult↗
PubMed1994

Fibroblast growth factor receptor type 1 expression during rat testicular development and its regulation in cultured Sertoli cells.

In the present study, we examined the ontogeny of the type 1 receptor for basic fibroblast growth factor (FGFR-1) in whole rat testis, its cellular localization, and its in vitro regulation in 20-day-old rat Sertoli cells. Gene expression of FGFR-1 was developmentally regulated; expression was higher in prepubertal testes and decreased with sexual maturity. The transcript was found to be expressed in Leydig-enriched fractions, peritubular cells, Sertoli cells, and, to a lesser extent, germ cells. FSH as well as (Bu)2cAMP enhanced FGFR-1 messenger RNA (mRNA) levels in cultured Sertoli cells, suggesting an involvement of the protein kinase-A pathway. Addition of basic FGF (bFGF), tumor necrosis factor-alpha (TNF alpha), or interleukin-1 alpha resulted in a dose- and time-related increase in FGFR-1 mRNA levels. The effect of bFGF was specific, because it was neutralized by cotreatment with an anti-bFGF. We tested medium conditioned by germ cells and found a stimulation of the Sertoli cell FGFR-1 mRNA levels, which was abolished by immunodepletion of the conditioned medium with anti-TNF alpha antibodies. It is suggested that in Sertoli cells, bFGF action, when mediated by FGFR-1, is under a complex hormonal (FSH) and paracrine and/or autocrine control exerted at least by bFGF, TNF alpha, and interleukin-1 alpha.

Aging↗
PubMed1994

Cloning and sequencing of the Atlantic salmon (Salmo salar) cytochrome c oxidase subunit III gene (coxIII) and analysis of coxIII expression during parr-smolt transformation.

Smoltification is the process whereby salmon alter their metabolism in preparation for movement from freshwater to seawater. Differential screening of a cDNA library prepared from post-smolt salmon liver mRNA led to the selection of a smoltification-induced sequence. Analysis of this cDNA revealed that it partially encoded subunit III of the enzyme cytochrome c oxidase. The complete coxIII sequence was amplified from salmon genomic DNA using consensus oligonucleotides based on ATPase 6 and tRNA(GLY) sequences from Pacific salmonid species. Cytochrome c oxidase subunit III liver mRNA levels were found to be significantly increased in salmon smolts. Northern blot analysis revealed a coxIII transcript of approximately 750 bp in all salmon tissues tested except blood. The DNA sequence of coxIII employs the mammalian mitochondrial genetic code and is strongly conserved when compared with that of other species.

Amino Acid Sequence↗
PubMed1994

[Career paths and professional education in the former German Democratic Republic 1949-1989].

With the unification of Germany the career structure and the places where nurses were educated and trained were pushed aside, as legislation of the Federal Republic was adopted. Thus they have acquired historical interest. Nevertheless they represent a quasi governmental experiment, the outcome of which should be recognised as a historical experience and should be preserved scientifically, because of the impact on the development of nursing-education, professionalization of nursing and most of all on the preparation of nurse-teachers. The authors of this paper are former nurses and educators in medical subject who were actively involved in developments, as teachers in hospitals and lecturers in teacher training colleges, since 1957 in the former DDR. The paper describes the organisation of nursing-education, the educational institutions in which this took place and the concurrent development of qualification for nurse teaching. What probably has most significance for the future is the experience gained between 1961 and 1974 in attaching nurses' professional training directly, without any time interval, to the 10th year of schooling. The outcome of this should be evaluated.

Career Mobility↗
PubMed1993

Localization of the colchicine-binding site of tubulin.

We have previously shown that rat brain tubulin, a heterodimer consisting of an alpha and beta monomer, can be covalently labeled with [3H]colchicine by near UV irradiation. Most of the label appears in beta-tubulin. We show here that beta-tubulin can be separated and purified from SDS preparative gels and analyzed by proteolysis. Chymotrypsin yielded a labeled approximately 4-kDa band that contained two peptides. Tryptic digestion also yielded an approximately 4-kDa band containing two peptides. Sequence analysis revealed a peptide of residues 1-36 and 213-242 for chymotrypsin and a peptide of residues 1-46 and 214-241 for trypsin. To identify which peptide carried the label, limited hydrolysis of beta-tubulin was done with trypsin; this procedure yielded a labeled 16-kDa N-terminal peptide and a 35-kDa C-terminal peptide, as identified by antibodies. Isolation of these peptides and extensive digestion with trypsin yielded two labeled peptides corresponding to residues 1-46 from the 16-kDa N-terminal fragment and residues 214-241 from the 35-kDa C-terminal fragment. These results show that at least two regions in beta-tubulin are specifically involved in colchicine binding and that the span of the colchicine molecule, < or = 11 A, bridges these two regions in the native beta monomer.

Animals↗
PubMed1993

Antimicrotubule properties of benzophenanthridine alkaloids.

Chelidonine, sanguinarine, and chelerythrine are natural benzophenanthridine alkaloids that inhibit taxol-mediated polymerization of rat brain tubulin in the micromolar range. Chelidonine is a weak, competitive inhibitor of colchicine binding to tubulin but does not inhibit podophyllotoxin binding. On the other hand, sanguinarine inhibits both colchicine and podophyllotoxin binding to tubulin with I50 values of 32 and 46 microM, respectively, and chelerythrine inhibits with I50 values of 55 and 60 microM, respectively. The inhibition by these two agents is of the mixed type. Tubulin forms an acid-reversible pseudobase with the imminium ion of sanguinarine, probably through several of its sulfhydryl groups, as shown by the loss of the yellow color of sanguinarine and its 596-nm fluorescence emission peak. Chelidonine, on the other hand, cannot undergo such pseudobase formation, and we conclude that it acts by a different mechanism. A number of previously described pharmacologic effects of these agents may be due to their inhibition of microtubule function.

Alkaloids↗
PubMed1993

Organization of a rainbow trout estrogen receptor gene.

The complete coding region of the estrogen receptor gene was isolated from a rainbow trout genomic library. This gene is divided into ten exons spanning at least 30 kb of genomic DNA. With two exceptions, intron positions are identical to those of the human estrogen receptor gene. The 5' end of the gene, including 1.7 kb of the promoter region, was sequenced. This region exhibits several putative regulatory elements. Localization of a potential estrogen responsive element to the first exon suggests that this gene is autoregulated. This 5' end region was also shown to be able to drive the expression of a CAT reporter gene in Xenopus laevis oocytes.

Amino Acid Sequence↗
PubMed1993

Nosocomial outbreak due to Enterococcus faecium highly resistant to vancomycin, penicillin, and gentamicin.

In October 1990, Enterococcus faecium that was highly resistant to glycopeptides, penicillins, and aminoglycosides was isolated from the peritoneal dialysis fluid from a patient in an intensive care unit. Over the following 6 months, multiresistant E. faecium organisms were isolated from cultures of blood, urine, or surgical wound specimens from eight additional patients. Surveillance cultures of groin and/or rectal swabs were positive for eight of 37 patients and four of 62 employees at risk. Restriction endonuclease digestion of chromosomal DNA from outbreak isolates was consistent with dissemination of a single strain throughout the intensive care unit. Strict infection control interventions contained the outbreak after several weeks. Review of patient charts suggested that renal insufficiency, length of hospital stay, duration of antibiotic treatment, and prior treatment with vancomycin were risks for infection due to multiresistant E. faecium. The emergence of multiple-drug-resistant enterococci presents serious infection control and therapeutic dilemmas.

Aged↗