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Biomedical subjects

D Grisaru

Publications and source records attributed to D Grisaru.

At least 19 recordsLinked to original sources
PubMed2001

Does histology influence prognosis in patients with early-stage cervical carcinoma?

BACKGROUND: The objective of this study was to examine the influence of histology on the outcome of patients with surgically treated, Stage IA-IB carcinoma of the uterine cervix. METHODS: All patient information was collected prospectively and was extracted subsequently from the University of Toronto cervical carcinoma surgery data base. Selection criteria for surgery were based on tumor size and were independent of histology. Patients with adenocarcinoma were separated into two groups: those with mucinous/endometrioid adenocarcinoma (M/E AC) and those with adenosquamous/clear cell adenocarcinoma (AS/CC AC). Statistical analysis used Wilcoxon rank tests, Mantel-Hanzel tests, chi-square tests, and Cox regression analyses. RESULTS: Between July 1984 and January 2000, 880 patients with Stage IA-IB cervical carcinoma underwent radical surgery, including pelvic lymphadenectomy, as the primary treatment. Two hundred fifty-five patients had M/E AC (29%), 81 patients had AS/CC AC (9%), and 544 patients had squamous cell carcinoma (SCC; 62%). Compared with patients who had SCC, patients with M/E AC had significantly more favorable prognostic characteristics: age (median, 39 years vs. 41 years; P < 0.03), depth of invasion (3.7 mm vs. 5.5 mm; P < 0.001), vascular space involvement (24% vs. 57%; P < 0.0001), Grade 2-3 tumor (40% vs. 78%; P < 0.0001), and pelvic lymph node metastases (4% vs. 8%; P < 0.04), respectively. Characteristics among patients with AS/CC AC tended have values similar to the median values for patients with SCC (or intermediate between the values for patients with M/E AC and the values for patients with SCC): age (38 years), depth of invasion (6 mm), vascular space involvement (40%), Grades 2-3 (70%), and pelvic lymph node metastases (6%). The 2-year and 5-year recurrence free survival rate was similar between patients with M/E AC and patients with SCC (95% vs. 94% and 90% vs. 90%, respectively); however, both were significantly superior to the rates for patients with AS/CC AC (2-year recurrence free survival rate: 86%, P < 0.03; 5-year recurrence free survival rate: 81%, P % 0.03). There were no differences in the pattern of first recurrence by histology. CONCLUSIONS: Patients with surgically treated Stage IA-IB cervical carcinoma with M/E AC and SCC histology have a similar prognosis. For patients with disease with AS/CC AC histology, the current results and the literature indicate that patients with uncommon histologies have an inferior recurrence free survival rate. Although the optimal therapy for these patients remains undefined, there is no obvious rationale for altering the treatment strategies from those currently employed for patients with M/E AC and SCC.

Adenocarcinoma↗
PubMed2001

Modified testicular expression of stress-associated "readthrough" acetylcholinesterase predicts male infertility.

Male infertility is often attributed to stress. However, the protein or proteins that mediate stress-related infertility are not yet known. Overexpression of the "readthrough" variant of acetylcholinesterase (AChE-R) is involved in the cellular stress response in a variety of mammalian tissues. Here, we report testicular overexpression of AChE-R in heads, but not tails, of postmeiotic spermatozoa from mice subjected to a transient psychological stress compared with age-matched control mice. Transgenic mice overexpressing AChE-R displayed reduced sperm counts, decreased seminal gland weight, and impaired sperm motility compared with age-matched nontransgenic controls. AChE-R was prominent in meiotic phase spermatocytes and in tails, but not heads, of testicular spermatozoa from AChE-R transgenic mice. Head-localized AChE-R was characteristic of human sperm from fertile donors. In contrast, sperm head AChE-R staining was conspicuously reduced in samples from human couples for whom the cause of infertility could not be determined, similar to the pattern found in transgenic mice. These findings indicate AChE-R involvement in impaired sperm quality, which suggests that it is a molecular marker for stress-related infertility.

Acetylcholinesterase↗
PubMed2001

Complex host cell responses to antisense suppression of ACHE gene expression.

3'-End-capped, 20-mer antisense oligodeoxynucleotides (AS-ODN) protected with 2'-O-methyl (Me) or phosphorothioate (PS) substitutions were targeted to acetylcholinesterase (AChE) mRNA and studied in PC12 cells. Me-modified AS-ODN suppressed AChE activity up to 50% at concentrations of 0.02-100 nM. PS-ODN was effective at 1-100 nM. Both AS-ODN displayed progressively decreased efficacy above 10 nM. In situ hybridization and confocal microscopy demonstrated dose-dependent decreases, then increases, in AChE mRNA. Moreover, labeling at nuclear foci suggested facilitated transcription or stabilization of AChE mRNA or both under AS-ODN. Intracellular concentrations of biotinylated oligonucleotide equaled those of target mRNA at extracellular concentrations of 0.02 nM yet increased only 6-fold at 1 microM ODN. Above 50 nM, sequence-independent swelling of cellular, but not nuclear, volume was observed. Our findings demonstrate suppressed AChE expression using extremely low concentrations of AS-ODN and attribute reduced efficacy at higher concentrations to complex host cell feedback responses.

Acetylcholinesterase↗
PubMed2001

ARP, a peptide derived from the stress-associated acetylcholinesterase variant, has hematopoietic growth promoting activities.

BACKGROUND: Psychological stress induces rapid and long-lasting changes in blood cell composition, implying the existence of stress-induced factors that modulate hematopoiesis. Here we report the involvement of the stress-associated "readthrough" acetylcholinesterase (AChE-R) variant, and its 26 amino acid C-terminal domain (ARP) in hematopoietic stress responses. MATERIALS AND METHODS: We studied the effects of stress, cortisol, antisense oligonucleotides to AChE, and synthetic ARP on peripheral blood cell composition and clonogenic progenitor status in mice under normal and stress conditions, and on purified CD34 cells of human origin. We employed in situ hybridization and immunocytochemical staining to monitor gene expression, and 5-bromo-2-deoxyuridine (BrdU), primary liquid cultures, and clonogenic progenitor assays to correlate AChE-R and ARP with proliferation and differentiation of hematopoietic progenitors. RESULTS: We identified two putative glucocorticoid response elements in the human ACHE gene encoding AChE. In human CD34+ hematopoietic progenitor cells, cortisol elevated AChE-R mRNA levels and promoted hematopoietic expansion. In mice, a small peptide crossreacting with anti-ARP antiserum appeared in serum following forced swim stress. Ex vivo, ARP was more effective than cortisol and equally as effective as stem cell factor in promoting expansion and differentiation of early hematopoietic progenitor cells into myeloid and megakaryocyte lineages. CONCLUSIONS: Our findings attribute a role to AChE-R and ARP in hematopoietic homeostasis following stress, and suggest the use of ARP in clinical settings where ex vivo expansion of progenitor cells is required.

Acetylcholinesterase↗
PubMed2000

Noonan syndrome: a cryptic condition in early gestation.

Noonan syndrome is one of the most common of genetic syndromes and manifests at birth, yet it is usually diagnosed during childhood. Although prenatal diagnosis of Noonan syndrome is usually not possible, in a few cases the ultrasonographic findings suggested the diagnosis in utero. Reported sonographic clues include septated cystic hygroma, hydrothorax, polyhydramnios, and cardiac defects, such as pulmonic stenosis and hypertrophic cardiomyopathy. During a 6-year period, 46,224 live-born infants were delivered at the Chaim Sheba Medical Center. Seven newborn infants and four fetuses were found to have Noonan syndrome. One fetus showed transient nuchal translucency of 4 mm and bilateral neck cysts at the 13th gestational week. Both findings resolved spontaneously by the 18th gestational week, but during the third trimester this fetus developed hydrothorax, skin edema, and polyhydramnios. In the three other fetuses, first- and second-trimester ultrasonographic findings were normal, and the diagnosis of Noonan syndrome was suggested only during the third trimester. All three fetuses had polyhydramnios and skin edema. A cardiac malformation, hydrothorax, and a large head were present in one fetus. Sonographic facial findings were investigated. In all four fetuses posteriorly angulated, apparently low-set ears and depressed nasal bridge were identified. Wide nasal base was seen in two fetuses. In two fetuses, persistent opening of the fetal mouth was interpreted as fetal hypotonia. One fetus developed progressive postnatal hypertrophic cardiomyopathy and in one case, pulmonic stenosis became apparent at age 6 months. This small series suggests that Noonan syndrome has an evolving phenotype during in utero and postnatal life. Amelioration of early nuchal region findings and late onset of the more "typical" ultrasonographic changes may limit early prenatal detectability.

Adult↗
PubMed2000

A transcription-activating polymorphism in the ACHE promoter associated with acute sensitivity to anti-acetylcholinesterases.

Hypersensitivity to acetylcholinesterase inhibitors (anti-AChEs) causes severe nervous system symptoms under low dose exposure. In search of direct genetic origin(s) for this sensitivity, we studied six regions in the extended 22 kb promoter of the ACHE gene in individuals who presented adverse responses to anti-AChEs and in randomly chosen controls. Two contiguous mutations, a T-->A substitution, disrupting a putative glucocorticoid response element, and a 4-bp deletion, abolishing one of two adjacent HNF3 binding sites, were identified 17 kb upstream of the transcription start site. Allele frequencies for these mutations were 0.006 and 0.012, respectively, in 333 individuals of various ethnic origins, with a strong linkage between the deletion and the biochemically neutral H322N mutation in the coding region of ACHE. Heterozygous carriers of the deletion included a proband who presented with acute hypersensitivity to the anti-AChE pyridostigmine and another with unexplained excessive vomiting during a fourth pregnancy following three spontaneous abortions. Electromobility shift assays, transfection studies and measurements of AChE levels in immortalized lymphocytes as well as in peripheral blood from both carriers and non-carriers, revealed functional relevance for this mutation both in vitro and in vivo and showed it to increase AChE expression, probably by alleviating competition between the two hepatocyte nuclear factor 3 binding sites. Moreover, AChE-overexpressing transgenic mice, unlike normal FVB/N mice, displayed anti-AChE hypersensitivity and failed to transcriptionally induce AChE production following exposure to anti-AChEs. Our findings point to promoter polymorphism(s) in the ACHE gene as the dominant susceptibility factor(s) for adverse responses to exposure or to treatment with anti-AChEs.

Acetylcholinesterase↗
PubMed2000

Connective tissue activating peptide III expression disappears progressively with increased dysplasia in human cervical epithelium.

OBJECTIVE: The aim of this study was to explore the possible involvement of CTAP-III in the development of cervical cancer as it progresses through several cervical intraepithelial neoplasia (CIN) stages. MATERIAL AND METHODS: Twenty-four cervical specimens were obtained by direct punch biopsy, conization, or hysterectomy. Diagnosis of CIN I to CIN III was based on standard morphological criteria in 12 specimens. Tissue specimens were also obtained from 4 normal uteri and 8 cases of invasive squamous cell cervical carcinoma. RT-PCR, using CTAP-III-specific primers, was used to identify CTAP-III mRNA and polyclonal antibodies, directed against the N-terminus of CTAP-III, for immunostaining of the CTAP-III protein. RESULTS: RT-PCR yielded amplified fragments in RNA derived from normal cervical tissue, while no PCR product was detected in the invasive cervical carcinoma tissue. The PCR product corresponded to a CTAP-III plasmid PCR product. Both tissues expressed the same amounts of GAPDH mRNA as the control for the integrity and equal amounts of the isolated RNA. In each of the 16 specimens of normal cervices and of CIN tissues, epithelial cells were stained with the anti-CTAP-III antibodies. In normal epithelium, CTAP-III staining was homogeneously distributed in all epithelial layers, except in the highly active and proliferating basal cells. CTAP-III was localized at the epithelial cell membrane or between adjacent epithelial cells in a granular, chain-like pattern of staining. In the CIN specimens, CTAP-III staining was no longer seen in the deep epithelial layers, consistent with the dysplastic appearance of the cells, and remained in the seemingly normal superficial epithelial layers. Cells of invasive cervical carcinoma did not stain for CTAP-III and were detected in endothelial cells of capillary blood vessels. CONCLUSION: The specific localization of CTAP-III between adjacent epithelial cells suggests a possible role of this chemokine in maintaining the normal architecture of epithelial tissues. Its progressive disappearance in increasingly severe CIN may be applied to distinguish between specific stages in the progression of cervical carcinoma.

Amino Acid Sequence↗
PubMed2000

Outcome of 306 twin deliveries according to first twin presentation and method of delivery.

The objective of this manuscript is to examine the effect of presentation of the first twin and mode of delivery on perintal outcome in twin deliveries. We reviewed all records of twin deliveries at a gestational age of 32 weeks and more from January 1, 1989 to December 31, 1995. Study cases were divided according to the first twin presentation (vertex = group A, nonvertex = group B) and then subdivided according to the planned mode of delivery, vaginal trial of labor (VTOL), and cesarean section (CS). The protocol for group A facilitated an attempt at vaginal delivery and for group B, vaginal delivery was considered as for a singleton fetus in breech presentation. Of 306 pairs of twins, 235 were in group A and 71 in group B. In group A, 219 women (93.2%) were eligible for VTOL, and the remaining 16 underwent CS. Thirty-three group B women were eligible for VTOL (46.5%; p<0.001) and 38 had CS. In group A, of the 219 candidates for VTOL, 199 (90.9%) delivered vaginally and 20 underwent a CS. In group B, of the 33 VTOL candidates 18 (54.5%) delivered vaginally and 15 underwent CS. Neonatal outcome did not differ in relation to the presentation of the first twin or the planned/actual mode of delivery. There were no cases of birth trauma, neurological complications, or perinatal mortality. Trial of vaginal labor is safe in twin deliveries with the first twin in vertex presentation. Provided criteria for vaginal breech delivery are adhered to, this also appears to be a reasonable option in twin deliveries with the first twin in nonvertex presentation.

Adult↗
PubMed1999

Manipulations of ACHE gene expression suggest non-catalytic involvement of acetylcholinesterase in the functioning of mammalian photoreceptors but not in retinal degeneration.

To explore role(s) of acetylcholinesterase (AChE) in functioning and diseased photoreceptors, we studied normal (rd/+) and degenerating (rd/rd) murine retinas. All retinal neurons, expressed AChEmRNA throughout fetal development. AChE and c-Fos mRNAs peaked at post-natal days 10-12, when apoptosis of rd/rd photoreceptors begins. Moreover, c-Fos and AChEmRNA were co-overexpressed in rd/rd mice producing transgenic human (h), and host (m) AChE, but not in rd/+ mice. However, mAChE overexpression also occurred in transgenics expressing human serum albumin. Drastic variations in AChE catalytic activity were ineffective during development. Neither transgenic excess nor diisopropylfluorophosphonate (DFP) inhibition (80%) affected the rd phenotype; nor did DFP exposure induce photoreceptor degeneration or affect other key cholinergic proteins in rd/+ mice, unlike reports of adult mice and despite massive induction under DFP of c-Fos70 years). Therefore, the extreme retinal sensitivity to AChE modulation may reflect non-catalytic function(s) of AChE in adult photoreceptors. These findings exclude AChE as causing the rd phenotype, suggest that its primary function(s) in mammalian retinal development are non-catalytic ones and indicate special role(s) for the AChE protein in adult photoreceptors.

Acetylcholinesterase↗
PubMed1999

Placing the newborn on the maternal abdomen after delivery increases the volume and CD34 cell content in the umbilical cord blood collected: an old maneuver with new applications.

OBJECTIVE: Our purpose was to increase the number of the progenitor cells in umbilical cord blood collected for transplantation. STUDY DESIGN: We randomly assessed the effect of "upper" and "lower" positions of the newborn on the volume and progenitor cell (CD34(+)) content of the umbilical cord blood collected from 49 healthy, vaginally delivered, term neonates. RESULTS: Twenty-two collections were performed in the "upper" and 27 in the "lower" position. The volume of umbilical cord blood obtained in the "upper" position was 108.1 +/- 19.1 mL compared with 42.6 +/- 19.5 mL in the "lower" position (P <.0001). Mononuclear cell separation revealed significantly higher numbers of cells in umbilical cord blood obtained in the "upper" group (P <.01). Although the percentage of CD34(+) cells was comparable, the absolute number of CD34(+) cells was significantly higher in the "upper" group because of the larger volume collected (P <.02). At 24 hours after delivery the hemoglobin levels were not significantly different between newborns of the 2 groups. CONCLUSIONS: Placing the newborn on the maternal abdomen after delivery and before cord clamping may significantly increase the volume of umbilical cord blood collected and therefore the CD34(+) counts that improve transplantation success without placing the mother or the newborn at risk.

Antigens, CD34↗
PubMed1999

Structural roles of acetylcholinesterase variants in biology and pathology.

Apart from its catalytic function in hydrolyzing acetylcholine, acetylcholinesterase (AChE) affects cell proliferation, differentiation and responses to various insults, including stress. These responses are at least in part specific to the three C-terminal variants of AChE which are produced by alternative splicing of the single ACHE gene. 'Synaptic' AChE-S constitutes the principal multimeric enzyme in brain and muscle; soluble, monomeric 'readthrough' AChE-R appears in embryonic and tumor cells and is induced under psychological, chemical and physical stress; and glypiated dimers of erythrocytic AChE-E associate with red blood cell membranes. We postulate that the homology of AChE to the cell adhesion proteins, gliotactin, glutactin and the neurexins, which have more established functions in nervous system development, is the basis of its morphogenic functions. Competition between AChE variants and their homologs on interactions with the corresponding protein partners would inevitably modify cellular signaling. This can explain why AChE-S exerts process extension from cultured amphibian, avian and mammalian glia and neurons in a manner that is C-terminus-dependent, refractory to several active site inhibitors and, in certain cases, redundant to the function of AChE-like proteins. Structural functions of AChE variants can explain their proliferative and developmental roles in blood, bone, retinal and neuronal cells. Moreover, the association of AChE excess with amyloid plaques in the degenerating human brain and with progressive cognitive and neuromotor deficiencies observed in AChE-transgenic animal models most likely reflects the combined contributions of catalytic and structural roles.

Acetylcholinesterase↗
PubMed1999

Human osteogenesis involves differentiation-dependent increases in the morphogenically active 3' alternative splicing variant of acetylcholinesterase.

The extended human acetylcholinesterase (AChE) promoter contains many binding sites for osteogenic factors, including 1,25-(OH)2 vitamin D3 and 17beta-estradiol. In differentiating osteosarcoma Saos-2 cells, both of these factors enhanced transcription of the AChE mRNA variant 3' terminated with exon 6 (E6-AChE mRNA), which encodes the catalytically and morphogenically active E6-AChE isoform. In contrast, antisense oligodeoxynucleotide suppression of E6-AChE mRNA expression increased Saos-2 proliferation in a dose- and sequence-dependent manner. The antisense mechanism of action was most likely mediated by mRNA destruction or translational arrest, as cytochemical staining revealed reduction in AChE gene expression. In vivo, we found that E6-AChE mRNA levels rose following midgestation in normally differentiating, postproliferative fetal chondrocytes but not in the osteogenically impaired chondrocytes of dwarf fetuses with thanatophoric dysplasia. Taken together, these findings suggest morphogenic involvement of E6-AChE in the proliferation-differentiation balance characteristic of human osteogenesis.

Acetylcholinesterase↗
PubMed1998

Effects of erythromycin on contractility of isolated myometrium from pregnant rats.

OBJECTIVE: Erythromycin is a stimulant of motor activity in the stomach, but its effects on the uterus have not been studied and only its antibiotic properties have been considered in the treatment of idiopathic preterm labor. The objective of this study was to characterize in vitro the effect of erythromycin on the contractility of the pregnant rat uterus. STUDY DESIGN: Myometrial strips from pregnant rats were suspended in tissue baths Isometric contractions were monitored by force transducers in response to various agents that were added to the bath solution. RESULTS: Erythromycin exposure caused a sustained decrease in phasic contractions induced by oxytocin or carbachol. This effect started at 0.01 mmol/L. At 1 mmol/L erythromycin reduced the contractions amplitude to 22% of the control and the frequency was reduced to 38% of control. CONCLUSION: We conclude that erythromycin produces a decrease in the pregnant rat myometrial activity in vitro, independent of the stimulant.

Animals↗
PubMed1998

Expansion of megakaryocyte progenitors from human umbilical cord blood using a new two-step separation procedure.

Cord blood (CB) transplantation is primarily performed in children, rather than in adults, due to the low number of haemopoietic progenitor cells obtained from the small volume of a single CB collection. Prolonged thrombocytopenia is a major problem following CB transplantation. Efforts are currently underway to expand the number of CB progenitor cells ex vivo, in order to enable transplantation in adults and to decrease the period of thrombocytopenia. In this study we investigated different techniques for enrichment and expansion of megakaryocyte (Mk) progenitor cells and haemopoietic stem cells from CB. CBs from 20 normal deliveries were depleted of red blood cells (RBC) by dividing each sample and testing cell separation on 3% gelatin, Hespan, Ficoll-Paque or a two-step 3% gelatin followed by Ficoll-Paque separation. The two-step procedure was found to be superior to the other methods in enrichment of the Mk progenitor cells (CFU-Mk) (34.3-fold), while at the same time retaining the number of myeloid and erythroid progenitors, CD34+ and CD41+ cells. In short-term (14d) liquid culture of non-adherent nucleated cells isolated by gelatin and Ficoll-Paque, a 40-fold expansion of clonable Mk progenitor cells was obtained in the presence of thrombopoietin (r-hu-TPO) and stem cell factor (r-hu-sCF. In similar cultures of isolated CD34+ cells, a 100-fold clonable Mk progenitor was obtained at day 14. Therefore this new technique may facilitate the ex vivo expansion of Mk progenitor cells and be adopted for future use in CB transplantation.

Adult↗
PubMed1997

The procoagulant activity of red blood cells from patients with severe preeclampsia.

OBJECTIVE: Our purpose was to determine whether red blood cells from patients with severe preeclampsia may exhibit increased membrane exposure of procoagulant phospholipids (i.e., phosphatidylserine), which may initiate intravascular clotting and platelet activation. STUDY DESIGN: The study group comprised 28 women: 9 with severe preeclampsia in the third trimester of pregnancy, 10 normotensive with uncomplicated pregnancies, and 9 age-matched, nonpregnant, healthy women. The exposure of phosphatidylserine on the outer membrane phospholipid layer was analyzed with use of isolated, washed red blood cells that were added as a source of phospholipids to a "prothrombinase" coagulation complex. RESULTS: The resultant thrombin formed was measured by an amidolytic assay. Thrombin generation significantly increased on the addition of red blood cells from women with preeclampsia (741 +/- 132 mU/ml/min) compared with red blood cells from normotensive pregnant (422 +/- 228 mU/ml/min) and nonpregnant women (316 +/- 268 mU/ml/min, p = 0.0008). CONCLUSION: This study indicates that in patients with preeclampsia the red blood cells exhibit a significant procoagulant surface that may trigger thrombin formation, thereby playing a role in the hypercoagulable state.

Adult↗
PubMed1997

Balloon catheter with extra-amniotic saline instillation: a method of induction in pregnancies at 41 or more gestational weeks.

One hundred five women with a documented pregnancy of 41 weeks' gestation or more, admitted for induction of labour by balloon catheter with extra-amniotic saline instillation, were retrospectively compared to 196 women admitted in spontaneous labour at the same gestational age, with regard to mode of delivery. The success rate of the induction group was 97.1%. The mode of delivery did not differ significantly between the 2 groups. The Caesarean section rates were 11.4% in the induction group versus 9.7% in the spontaneous group. The mode of delivery after induction of labour by balloon catheter with extra-amniotic saline instillation and simultaneously commenced intravenous oxytocin infusion, in pregnancies of 41 weeks or more, is similar to that of spontaneous deliveries at the same gestational age.

Adult↗