Adolescent alcohol exposure persistently alters orbitofrontal cortical encoding of Pavlovian conditional stimulus components in female rats.

Exposure to alcohol during adolescence impacts cortical and limbic brain regions undergoing maturation. In rodent models, long-term effects on behavior and neurophysiology have been described after adolescent intermittent ethanol (AIE), especially in males. We hypothesized that AIE in female rats increases conditional approach to a reward-predictive cue and corresponding neuronal activity in the orbitofrontal cortex (OFC) and nucleus accumbens (NAc). We evaluated behavior and neuronal firing after AIE (5 g/kg intragastric) or water (CON) in adult female rats. Both AIE and CON groups expressed a ST phenotype, and AIE marginally increased sign-tracking (ST) and decreased goal-tracking (GT) metrics. NAc neurons exhibited phasic firing patterns to the conditional stimulus (CS), with no differences between groups. In contrast, neuronal firing in the OFC of AIE animals was greater at CS onset and offset than in CON animals. During reward omission, OFC responses to CS offset normalized to CON levels, but enhanced OFC firing to CS onset persisted in AIE. We suggest that the enhanced OFC neural activity observed in AIE rats to the CS could contribute to behavioral inflexibility. Ultimately, AIE persistently impacts the neurocircuitry of reward-motivated behavior in female rats.

Solar heterogeneous photo-Fenton for complete inactivation of Escherichia coli and Salmonella typhimurium in secondary-treated wastewater effluent.

In this work, complete elimination of Escherichia coli and Salmonella typhimurium was achieved in 120 min using a heterogeneous photo-Fenton process under sunlight at pH 6.5 in distilled water. A face-centered composite central design 22 with one categoric factor and three replicates at the central point was used to evaluate the effect of iron (III) oxide concentration (0.8-3.4 mg L-1), H2O2 (2-10 mg L-1), and the type of iron oxide phase (maghemite and hematite) on the inactivation of both bacteria. The results showed that the amount of catalyst, H2O2 concentration and their interaction were significant factors (p < 0.05) in the elimination of the microorganisms. Thus, under the best conditions (3.4 mg L-1 of iron (III) oxide and 10 mg L-1 of H2O2) in the experimental ranges, complete inactivation of E. coli and S. typhimurium was achieved (6-log reduction) in 120 min using the photo-Fenton treatment with both iron-oxide phases. Furthermore, the photocatalytic elimination of both bacteria by the photo-Fenton process using hematite and maghemite in secondary-treated wastewater effluent was performed obtaining slower inactivation rates (1.2-5.9 times) than in distilled water due to the matrix effect of the effluent from a wastewater treatment plant. Nevertheless, the process continued to be effective in the effluent, achieving complete bacterial elimination in 150 min using the hematite phase. Additionally, the SEM images of the bacterial cells showed that the heterogeneous photo-Fenton treatment generated permanent and irreversible cell damage, resulting in complete cell death.

A cold wave of winter 2021 in central South America: characteristics and impacts.

During the austral winter (June-August) of 2021, the meteorological services of Brazil, Argentina, Peru, Paraguay, Bolivia, and Chile all issued forecasts for unusually cold conditions. Record-low minimum temperatures and cold spells were documented, including one strong cold wave episode that affected 5 countries. In this study, we define a cold wave as a period in which daily maximum and minimum air temperatures are below the corresponding climatological 10th percentile for three or more consecutive days. The intense cold wave event in the last week of June, 2021, resulted in record-breaking minimum daily temperatures in several places in central South America and Chile. Several locations had temperatures about 10 °C below average, central South America had freezing conditions, and southern Brazil even saw snow. The cold air surge was characterized by an intense upper-air trough located close to 35° S and 70° W. The southerly flow to the west of this trough brought very cold air northward into subtropical and tropical South America. A northward flow between the lower-level cyclonic and anticyclonic perturbations caused the intense southerly flow between the upper-level ridge and trough. This condition facilitated the inflow of near-surface cold air from southern Argentina into southeastern Brazil and tropical South America east of the Andes. In the city of São Paulo, the cold wave caused the death of 13 homeless people from hypothermia. Frost and snow across southern and southeastern Brazil caused significant damage to coffee, sugarcane, oranges, grapes, and other fruit and vegetable crops. Wine and coffee production fell, the latter by 30%, and prices of food and commodities in the region rose. Supplementary Information: The online version contains supplementary material available at 10.1007/s00382-023-06701-1.

A strategic reflection for the management and implementation of CAR-T therapy in Spain: an expert consensus paper.

CAR-T cell therapy represents a therapeutic revolution in the prognosis and treatment of patients with certain types of hematological cancer. However, they also pose new challenges in the healthcare, regulatory and financial fields. The aim of the RET-A project was to undertake a strategic reflection on the management of CAR-T therapies within the Spanish National Health System, to agree on recommendations that will help to better deal with the new context introduced by these cell therapies in the present and in the future. This think tank involved 40 key agents and opinion leaders. The experts identified three great challenges for implementing advanced therapies in Spain: therapeutic individualisation, with a multidisciplinary approach; acceleration of access times, by minimizing bureaucracy; and increase in the number of centers qualified to manage the CAR-T therapies in the NHS. The experts agreed on the ideal criteria for designating those qualified centers. They also agreed on a comprehensive CAR-T care pathway with the timings and roles which would ideally be involved in each part of the process.

Biomarkers and intermediate-high risk non-muscle invasive bladder cancer: a multivariate analysis of three different cellular pathways with pronostic implications.

PURPOSE: To determine the presence of a group of mutations, and establish the prognostic value for recurrence and progression. MATERIALS AND METHODS: Prospective observational study. Intermediate-to-high-risk non-muscle invasive bladder cancer (NMIBC) was evaluated. Data from genetic analyses were included in a database along with clinicopathological variables of interest. RESULTS: Seventy-four patients. Twenty-five (33.8%) recurred and 3 (4.1%) progressed. Median time to recurrence: 8 months (5.7-12.7). Median time to progression: 14 months (P75: 12). Mutation distribution: KRAS codon 12: one patient (1.4%), BAT25: five patients (6.8%), BAT-26: four patients (5.4%), and D2S123: 6 patients (8.1%). Arg72Pro polymorphism: 50 patients (67.6%) exhibited homozygous mutations, 23 (31.1%) were heterozygous, and 1 patient (1.4%) did not present the mutation. We found an association between presence of MSI at BAT26 and female sex (p < 0.05) and tumor stage and the TP53 Arg72Pro polymorphism. Recurrence-free survival (RFS) was significantly associated with presence of MSI at D2S123, with a HR of 5.44 for patients presenting the mutation (95% CI 1.83-16.16). On multivariate analysis, we found a statistically significant increase in risk of recurrence among patients with MSI at D2S123 (HR 5.15; p < 0.05) and more than 2 previous transurethral bladder resections (TURBs) (HR 5.07; p < 0.05) adjusted for tumor stage and grade. Harrell's concordance index revealed an accuracy of 0.74 (p < 0.05). CONCLUSION: An association was found between presence BAT26 MSI and female sex, Arg72Pro polymorphism with tumor stage and D2S123 and more than 2 TUR procedures were associated with RFS adjusted to tumor stage and grade.

Fathers matter too! Lived experience of pedagogical hope in raising children with Down syndrome.

BACKGROUND: Pedagogical hope is a fundamental disposition for raising children. This attitude among fathers of children with Down syndrome (DS) plays an essential role in their children's development. This phenomenological study sought to explore fathers' lived experiences and to reflect on what it means to be a pedagogically hopeful father of a child with DS. METHODS: Max van Manen's hermeneutic-phenomenological method was applied. Phenomenological interviews were held with 10 fathers of children with DS in Spain, Ecuador and Scotland. Anecdotal narratives from the transcribed interviews were analysed based on philosophical, philological and human science methods. RESULTS: The four eidetic themes in the phenomenological text show how a pedagogically hopeful father (1) is realistic; (2) believes in the strengths of his child with DS; (3) trusts in his positive influence; and (4) is open to unexpected surprises. CONCLUSIONS: Lived experiences of pedagogical hope reveal fathers' fundamental roles in stimulating the utmost development of their child's capabilities. Reflecting on this pedagogical attitude will undoubtedly encourage fathers, educators and health care professionals to make the most of this disposition and enhance their relationship with their children with DS.

Ascitis secundaria a chlamydia trachomatis tras procedimiento de reproducción asistida / Ascites secondary to chlamydia trachomatis after assisted reproduction procedure

El desarrollo de ascitis moderada o severa es infrecuente tras una enfermedad inflamatoria pélvica por Chlamydia trachomatis, una de las principales causas de infección de transmisión sexual a nivel mundial. Caso clínico: Paciente de 29 años que tras aborto diferido (gestación tras inseminación artificial) que inicia a las seis semanas con cuadro de dolor abdominal inespecífico y ascitis de predominio linfocitario. El diagnostico se realizo mediante PCR (Werfen®) tanto el liquido ascítico como en exudado endocervical. La paciente recibió tratamiento antibiótico con doxiciclina. Conclusión: Las enfermedades de transmisión sexual deben ser consideradas cuando se realiza un diagnóstico diferencial de una mujer sexualmente activa con dolor abdominal y ascitis, instaurar tratamiento antibiótico y evitar pruebas e intervenciones quirúrgicas innecesarias.

The development of moderate or severe ascites is infrequent after a pelvic inflammatory disease from Chlamydia trachomatis, one of the main causes of sexually transmitted infection worldwide. Clinical case: A 29-year-old patient who, after a delayed abortion (gestation after artificial insemination), started at six weeks with symptoms of non-specific abdominal pain and predominantly lymphocytic ascites. The diagnosis is made by PCR (Werfen®) both the ascitic fluid and the endocervical exudate. The patient received antibiotic treatment with doxycycline. Conclusion: Sexually transmitted diseases should be considered when making a differential diagnosis of a sexually activated woman with abdominal pain and ascites. Establishing antibiotic treatment, and avoiding unnecessary tests and surgical treatments.

Scar sarcoidosis: A rare entity found by 18F-FDG-PET/CT.

18F-labeled fluoro-2-positron deoxyglucose emission tomography/computed tomography has been widely used in malignancy assessment, however, is not tumor-specific and may be taken up by non-malignant conditions such as sarcoidosis. Sarcoidosis is a systemic inflammatory disorder and scar sarcoidosis is a rare manifestation of the disease. A 60-year-old man with a past medical history of synchronous colon adenocarcinoma and clear cell renal cell carcinoma with clinical suspicion of tumor recurrence. 18F-labeled fluoro-2-positron deoxyglucose emission tomography/computed tomography scan demonstrated lesions with increased fluorodeoxyglucose uptake in mediastinal and left supraclavicular lymph nodes, along with hypermetabolic cutaneous foci that corresponded with previous surgical scars. Skin biopsy was suggestive of sarcoidosis.

Epidemiological Characteristics of the Largest Kidney Transplant Program in Mexico: Western National Medical Center, Mexican Institute of Social Security.

BACKGROUND: According to the National Transplant Center (CENATRA), in 2013, a total of 2707 transplantations were performed in Mexico; of them, 10% (270 transplantations) were done in our Tertiary Care Hospital (Western National Medical Center). This means that one in 10 transplant recipients undergoes transplantation at our medical center. The aim of our study was to describe the characteristics of and to compare changes in the kidney transplantation program over time. MATERIALS AND METHODS: This was a cross-sectional study. Data were collected from the hospital transplant registry from January 1994 to December 2014. RESULTS: During the study period, 3643 kidney transplantations were conducted; most were living donor 3236 (89%), and only 407 patients (11%) received a graft from a deceased donor. Of living donors, 2786 (87%) were related, and 450 (13%) were genetically unrelated. The average recipient age was 28 years, and the average age of the donor was 34 years. It was observed that siblings donated more frequently (51%), followed by parents (34%). Among unrelated donors, spouses donated the most (66%). In 80% of cases, the cause of end-stage renal disease (ESRD) was unknown (80%). The most frequent renal replacement therapy was peritoneal dialysis (54%), followed by hemodialysis (18%); only 5% of patients received preemptive kidney transplant. The most frequent immunosuppression scheme was tacrolimus, mycophenolate mofetil, and prednisone in 70% of patients. CONCLUSION: The Western National Medical Center is the largest kidney transplantation program in Mexico. The main activity is living donor transplantation. Recipients are relatively young persons with unknown etiology of ESRD.

Early Steroid Withdrawal in Recipients of a Kidney Transplant From a Living Donor: Experience of a Single Mexican Center.

BACKGROUND: Early steroid withdrawal (ESW) can improve lipid and hemodynamic profiles without severe acute rejection (AR) events in renal transplant patients. Our objective was to evaluate the effects of ESW on the frequency and severity of AR. METHODS: A randomized, open-label, controlled clinical trial was performed on renal transplant recipients with a follow-up of 12 months. In the ESW group, patients were selected for corticosteroid treatment withdrawal on the fifth day post transplantation. In the Control group, patients continued with steroid treatment. All patients were over 18 years of age with panel reactive antibody (PRA) class I and II HLA <20%. RESULTS: In total, 71 patients, 37 in the ESW group (52.1%) and 34 in the Control group (47.9%), had comparable AR incidences at the end of the follow-up (16% vs 15%) (NS) (RR = 1.20, 95% CI = 0.32-3.33). Although renal graft survival was similar between the ESW and Control groups (87% vs 94%), renal function was superior in the ESW group (85 vs 75 mL/min). Additionally, hypertension was less frequent in the ESW group (3% vs 35%), requiring the use of fewer antihypertensives (8% vs 50%). CONCLUSIONS: ESW was also associated with better blood pressure control and similar AR risk. The ESW group exhibited stable renal function.

Increased Helicobacter pylori-associated gastric cancer risk in the Andean region of Colombia is mediated by spermine oxidase.

Helicobacter pylori infection causes gastric cancer, the third leading cause of cancer death worldwide. More than half of the world's population is infected, making universal eradication impractical. Clinical trials suggest that antibiotic treatment only reduces gastric cancer risk in patients with non-atrophic gastritis (NAG), and is ineffective once preneoplastic lesions of multifocal atrophic gastritis (MAG) and intestinal metaplasia (IM) have occurred. Therefore, additional strategies for risk stratification and chemoprevention of gastric cancer are needed. We have implicated polyamines, generated by the rate-limiting enzyme ornithine decarboxylase (ODC), in gastric carcinogenesis. During H. pylori infection, the enzyme spermine oxidase (SMOX) is induced, which generates hydrogen peroxide from the catabolism of the polyamine spermine. Herein, we assessed the role of SMOX in the increased gastric cancer risk in Colombia associated with the Andean mountain region when compared with the low-risk region on the Pacific coast. When cocultured with gastric epithelial cells, clinical strains of H. pylori from the high-risk region induced more SMOX expression and oxidative DNA damage, and less apoptosis than low-risk strains. These findings were not attributable to differences in the cytotoxin-associated gene A oncoprotein. Gastric tissues from subjects from the high-risk region exhibited greater levels of SMOX and oxidative DNA damage by immunohistochemistry and flow cytometry, and this occurred in NAG, MAG and IM. In Mongolian gerbils, a prototype colonizing strain from the high-risk region induced more SMOX, DNA damage, dysplasia and adenocarcinoma than a colonizing strain from the low-risk region. Treatment of gerbils with either α-difluoromethylornithine, an inhibitor of ODC, or MDL 72527 (N(1),N(4)-Di(buta-2,3-dien-1-yl)butane-1,4-diamine dihydrochloride), an inhibitor of SMOX, reduced gastric dysplasia and carcinoma, as well as apoptosis-resistant cells with DNA damage. These data indicate that aberrant activation of polyamine-driven oxidative stress is a marker of gastric cancer risk and a target for chemoprevention.

Efficacy of nitroglycerine infusion versus sublingual nifedipine in severe pre-eclampsia: a randomized, triple-blind, controlled trial.

1. Information regarding the use of continuous i.v. administration of nitroglycerine as an antihypertensive agent in the management of pre-eclampsia is scarce. In the present study, i.v. nitroglycerine or sublingual nifedipine were administered to 32 women with severe pre-eclampsia who were being managed with controlled plasma volume expansion and MgSO(4) loading and maintenance doses. Maternal blood pressure and heart rate responses, fetal heart rate responses and perinatal fetal-maternal adverse effects were evaluated using classical parametric and non-parametric data analysis and data modelling by mixed models. 2. An important hypotensive response was observed in both groups, although this reponse was greater, faster and exhibited less variability (more precision) in the nitroglycerine-treated group. Heart rate also increased in both the nitroglycerine- and nifedipine-treated groups (4.6 +/- 4.4 vs 8.6 +/- 5.3 b.p.m., respectively), although the increase in the nifedipine-treated group was almost twofold that in the nitroglycerine-treated group. There were no significant changes in fetal heart rate in response to vasodilator therapy. The frequency of perinatal fetal-maternal adverse effects was similar in both groups at 40% and the adverse effects observed included flushing, headache, palpitations and nausea. 3. In conclusion, i.v. infusion of nitroglycerine is an effective, safe and alternative therapy for severe pre-eclampsia.

PET-CT in clinical oncology.

Anatomic imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) have been used for many years in clinical oncology. The emergence of positron emission tomography (PET) more than a decade ago was a major breakthrough in the early diagnosis of malignant lesions, as it was based on tumour metabolism and not on anatomy. The merger of both techniques into one thanks to PET-CT cameras has made this technology the most important tool in the management of cancer patients. PET/CT with 18F-FDG is increasingly being used for staging, restaging and treatment monitoring for cancer patients with different types of tumours (lung, breast, colorectal, lymphoma, melanoma, head and neck etc.). At many institutions, PET/CT has replaced separately acquired PET and CT examinations for many oncologic indications. This replacement has occurred despite the fact that only a relatively small number of well designed prospective studies have verified imaging findings against the gold standard of histopathologic tissue evaluation. However, a large number of studies have used acceptable reference standards, such as pathology, imaging and other clinical follow-up findings, for validating PET/CT findings. The impact on the management of patients and the benefits from the information obtained from this anatomo-metabolic procedure justify the term "clinical oncology based on PET-CT" as a new concept to be applied in clinical practice.

Measurement of liver iron overload by magnetic induction using a planar gradiometer: preliminary human results.

The measurement of hepatic iron overload is of particular interest in cases of hereditary hemochromatosis or in patients subject to periodic blood transfusion. The measurement of plasma ferritin provides an indirect estimate but the usefulness of this method is limited by many common clinical conditions (inflammation, infection, etc). Liver biopsy provides the most quantitative direct measurement of iron content in the liver but the risk of the procedure limits its acceptability. This work studies the feasibility of a magnetic induction (MI) low-cost system to measure liver iron overload. The excitation magnetic field (B0, frequency: 28 kHz) was produced by a coil, the perturbation produced by the object (deltaB) was detected using a planar gradiometer. We measured ten patients and seven volunteers in supine and prone positions. Each subject was moved in a plane parallel to the gradiometer several times to estimate measurement repeatability. The real and imaginary parts of deltaB/B0 were measured. Plastic tanks filled with water, saline and ferric solutions were measured for calibration purposes. We used a finite element model to evaluate the experimental results. To estimate the iron content we used the ratio between the maximum values for real and imaginary parts of deltaB/B0 and the area formed by the Nyquist plot divided by the maximum imaginary part. Measurements in humans showed that the contribution of the permittivity is stronger than the contribution of the permeability produced by iron stores in the liver. Defined iron estimators show a limited correlation with expected iron content in patients (R < or = 0.56). A more precise control of geometry and position of the subjects and measurements at multiple frequencies would improve the method.

Comparison of equivalence and determination of diagnostic utility of min-mod and clamp methods for insulin resistance in diabetes free subjects: a meta-analysis.

The gold standard for quantifying insulin sensitivity (IS) is the hyperinsulinemic-euglycemic clamp (Clamp) with a cut-off point of 5x10-2 (dL/min)/(microU/mL) or less to indicate insulin resistance. Bergman's minimal model (Min-Mod) is also being used to estimate IS, but there are doubts as to its equivalence with Clamp. The objective of the present study is to determine if Clamp and the tolbutamide and insulin techniques of Min-Mod are equivalent. Meta-analysis based on a bibliographic search from 1970 until the present was made for the MeSH terms: insulin resistance, hyperglycemic-clamp, euglycemic-clamp, Min-Mod, minimal model approach. Concordance was determined with both simple and intraclass correlation and Bland and Altman's concordance limits using R. Three of the 109 articles found were included. The concordance limits indicate that Clamp and Min-Mod are not equivalent, which could result in diagnostic errors if the accepted cut-off point is used for both methods. Given this lack of equivalence, a ROC analysis was performed and new diagnostic cut-off points of 2.4 and 4.6x0-2 (dL/min)/(microU/mL) for insulin and tolbutamide techniques of Min-Mod, respectively, are proposed, with adequate sensitivity, specificity, and predictive value. These values should be prospectively validated.

Histamine H3 receptor activation inhibits glutamate release from rat striatal synaptosomes.

The release of glutamate from striatal synaptosomes induced by depolarisation with 4-aminopyridine (4-AP) was studied by a method based on the fluorescent properties of the NAPDH formed by the metabolism of the neurotransmitter by glutamate dehydrogenase.Ca(2+)-dependent, depolarisation-induced glutamate release was inhibited in a concentration-dependent manner by the selective histamine H(3) agonist immepip. Best-fit estimates were: maximum inhibition 60+/-10% and IC(50) 68+/-10 nM. The effect of 300 nM immepip on depolarisation-evoked glutamate release was reversed by the selective H(3) antagonist thioperamide in a concentration-dependent manner (EC(50) 23 nM, K(i) 4 nM). In fura-2-loaded synaptosomes, the increase in the intracellular concentration of Ca(2+) ([Ca(2+)](i)) evoked by 4-AP-induced depolarisation (resting level 167+/-14 nM; Delta[Ca(2+)](i) 88+/-15 nM) was modestly, but significantly reduced (29+/-5% inhibition) by 300 nM immepip. The action of the H(3) agonist on depolarisation-induced changes in [Ca(2+)](i) was reversed by 100 nM thioperamide. Taken together, our results indicate that histamine modulates the release of glutamate from corticostriatal nerve terminals. Inhibition of depolarisation-induced Ca(2+) entry through voltage-dependent Ca(2+) channels appears to account for the effect of H(3) receptor activation on neurotransmitter release. Modulation of glutamatergic transmission in rat striatum may have important consequences for the function of basal ganglia and therefore for the control of motor behaviour.

Efficacy of human recombinant DNase in pediatric patients with cystic fibrosis.

BACKGROUND: Most respiratory complications in cystic fibrosis (CF) arise from abnormally viscid mucus, and rhDNase has shown to be effective in enhancing mucous clearance. We explored the responses to rhDNase in a Mexican population of CF patients. METHODS: Patients with CF received aerosolized rhDNase (2.5 mg daily) during 3 months, followed by daily aerosolized placebo during 3 months. RESULTS: A total of 21 CF patients entered the study (11.1 +/- 0.5 years of age, mean +/- SEM, 10 girls): 15 patients (71%) had basal forced vital capacity (FVC) higher than the 70% predicted value, and the remainder of the patients had an FVC of between 30 and 70%. As a group, rhDNase progressively increased the forced expiratory flow at 1 sec (FEV1) as well as the FVC, reaching statistical significance (p <0.005) at the end of the third month of treatment. Sputum production and difficulty to expectorate or to breathe also improved during the rhDNase treatment period (p <0.05 to p <0.001). All these changes progressively decreased to basal values after 3 months with aerosolized placebo. Adverse reactions were almost null, with a sole patient reporting dysphonia. CONCLUSIONS: Aerosolized rhDNase was effective in progressively improving respiratory function and symptoms in most CF patients.

Fetal amniotic adhesions. Their topographic concordance with regionally clustered malformations.

BACKGROUND: The amniotic band disruption complex (ABDC) has been segregated recently into various phenotypes. In view of the pathogenic mechanisms that have been proposed, this study was designed to assess if it is one variable process or is composed of several distinct complexes. METHODS: The 48 cases of fetuses with bands or placenta attached to fetal parts cited in this paper included nine new cases and 39 from the literature. They were organized first according to the embryonal topography of the malformations, then according to the position of the adhesions, and finally by the assessment of distances between the cases and between the malformations using the squared Euclidean distances for binary variables and cluster analysis. RESULTS: In all three analyses, three groups were identified: 1) fetuses with cephalo-thoracic anomalies; 2) fetuses with caudal anomalies, and 3) fetuses with mixed anomalies. Nonetheless, overlap among the three groups was apparent. Thus, while fetuses with amniotic bands form three clusters, it appears that these are part of a spectrum and should be considered as variable manifestations of a single entity resulting from a single pathogenetic mechanism. An association was established between the localization of the adhesions and the malformations in various axes. Abdominoschisis, however, was not particularly related to adhesions at one or the other end of the fetus; a short umbilical cord was an almost universal finding. Single umbilical artery (SUA) was especially related to caudal adhesions and malformations (p = 0.004 and 0.001), as well as abdominoschisis (p = 0.002) and agenesis of the abdominal organs (p = 0.008). CONCLUSIONS: The association between amniotic adhesions to the fetus and multiple malformations occurring predominantly in the same area suggest that the former are the cause of the latter. The association of abdominoschisis, as well as a short umbilical cord, with malformations and adhesions in all areas, suggests that these are secondary phenomena to generalized embryonal and fetal tension. SUA, however, with a specifically regional association, is more likely to be due to disruption from exposure in cases with abdominoschisis, often accompanying the loss of abdominal organs.

Interaction of CBF alpha/AML/PEBP2 alpha transcription factors with nucleosomes containing promoter sequences requires flexibility in the translational positioning of the histone octamer and exposure of the CBF alpha site.

Chromatin remodeling at eukaryotic gene promoter sequences accompanies transcriptional activation. Both molecular events rely on specific protein-DNA interactions that occur within these promoter sequences. Binding of CBFalpha/AML/PEBP2alpha (core binding factor alpha/acute myelogenous leukemia/polyoma enhancer binding protein 2alpha) proteins is a key event in both tissue-specific and developmentally regulated osteocalcin (OC) promoter activity. To address linkage between chromatin organization and transcription factor binding, we reconstituted segments of the rat OC gene proximal promoter into mononucleosomes and studied binding of CBFalpha proteins. We analyzed binding of bacterially produced Cbfalpha2Alpha and Cbfalpha2B, two splice variants of the human CBFalpha2 gene, and determined the effect of heterodimerization with the Cbfbeta subunit on binding activity. Our results indicate that binding of the truncated Cbfalpha2A protein to naked DNA is independent of Cbfbeta whereas Cbfalpha2A binding to nucleosomal DNA was enhanced by Cbfbeta. In contrast, the Cbfalpha2B interaction with either naked or nucleosomal DNA was strongly dependent on heterodimerization with the Cbfbeta subunit. Additionally, our results demonstrate that both Cbfalpha2A alone and Cbfalpha2B complexed with Cbfbeta can interact with nucleosomal DNA only if there is a degree of flexibility in the positioning of the histone octamer on the DNA fragment and exposure of the CBFalpha site. This situation was achieved with a DNA segment of 182 bp from the rat OC promoter that preferentially positions mononucleosomes upstream of the CBFalpha binding site and leaves this element partially exposed. Taken together, these results suggest that nucleosomal translational positioning is a major determinant of the binding of CBFalpha factors to nucleosomal DNA.