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R Real

Publications and source records attributed to R Real.

7 recordsLinked to original sources
PubMed2004

Response of the haematocrit to body condition changes in Northern Bald Ibis Geronticus eremita.

We study the usefulness of the haematocrit as a predictor of body condition in birds, using a captive population of the endangered species Northern Bald Ibis (Geronticus eremita). This population is 14% of the worldwide captive population, which is far greater than the known free-living population. The haematocrit, body mass and body condition index responded in the same sense to two different nutritional periods, and there was a statistically significant relationship between changes in condition index and haematocrit of individual birds between the two periods. We discuss the relationship of these parameters with subcutaneous fat and muscle mass, and analyse the individuals' nutritional status in each of the periods studied. The conclusion was that the haematocrit is sensitive to variations in body condition since it responds to mass-loss processes corresponding to phases of mobilization of fat reserves, a situation prior to the mobilization of muscle proteins when there is a manifest deterioration of the individual's aspect.

Adipose Tissue↗
PubMed2001

Impaired hyperpolarization in regenerated endothelium after balloon catheter injury.

Ca(2+)-activated K(+) (K(Ca)) channels control endothelial Ca(2+) homeostasis and the formation of vasodilators. After angioplasty, dysfunction of the regenerated endothelium leads to abnormal vasoregulation. In this study, we tested the expression and function of K(Ca) channels in regenerated endothelium at 6 weeks after balloon catheter injury of rat carotid arteries (CAs) by using single-cell reverse transcription-polymerase chain reaction, patch-clamp techniques, and analysis of vasoreactivity. In single regenerated endothelial cells (ECs), the percentage of ECs expressing the K(Ca) genes, rSK3 (12+/-8%) and rIK1 (22+/-9%), was significantly lower compared with the percentage of native ECs expressing these genes (rSK3 58+/-8%, rIK1 64+/-10%). In patch-clamp experiments, K(Ca) currents and acetylcholine-induced hyperpolarization were markedly reduced in regenerated ECs (shift of membrane potential -6+/-3 mV) compared with those in native ECs (shift of membrane potential -21+/-5 mV). In pressure myograph experiments, acetylcholine-induced dilation was impaired in reendothelialized CAs compared with normal CAs. Intraluminal application of the K(Ca) blocker apamin and charybdotoxin inhibited dilation by 30% in normal CAs but was without effect in reendothelialized CAs. Intraluminal application of 1-ethyl-2-benzimidazolinone (100 micromol/L), an opener of K(Ca) channels, evoked dilation by 29% in normal CAs but had no effect in reendothelialized CAs. In conclusion, the impaired expression of K(Ca) channels in regenerated endothelium results in defective hyperpolarization and impaired dilation. Thus, the impaired K(Ca) channel function contributes to functional alterations of regenerated endothelium after angioplasty.

Acetylcholine↗
PubMed2001

Transcriptional mechanism of protein kinase C-induced isoform-specific expression of the gene for endothelin-converting enzyme-1 in human endothelial cells.

Isoform-specific expression of endothelin-converting enzyme (ECE)-1, the major big endothelin-processing enzyme, is controlled by alternative promoters. Signaling pathways and transcriptional mechanisms of ECE-1 mRNA expression are largely unknown. To investigate ECE-1 isoform expression after protein kinase C (PKC) activation, we used phorbol 12-myristate 13-acetate (PMA) to stimulate primary cultured human umbilical vein endothelial cells and the related EA.hy926 cell line. ECE-1a mRNA was up-regulated (approximately 3-fold), whereas mRNA of alternative isoforms (b, c, and d) was unchanged, which was confirmed on the protein level. PMA effects on mRNA expression were suppressed by the PKC inhibitors H-7 and Calphostin C. Because increased ECE-1a expression was preceded by induction of the transcription factor Ets-1, we performed gel shift assays and demonstrated specific DNA/protein interactions involving the ETS binding motif GGAA. Luciferase reporter assays showed that PMA induced ECE-1a promoter activity about 2.5-fold in EA.hy926 cells. Similarly, coexpression of Ets-1 protein resulted in a dose-dependent increase in ECE-1a promoter activity (more than 8-fold). Using gel shift assays and mutation analysis, we identified two tandemly arranged Ets-1 binding sites (EBS) at -638 and -658, respectively, that are involved in transcriptional activation of the ECE-1a promoter by PMA or Ets-1. Moreover, we also found evidence for binding of a transcriptional repressor to EBS -638. The inhibitor of mitogen-activated protein kinase kinase, PD98059, inhibited PMA effects on ECE-1a mRNA expression and promoter activity, respectively. Our results provide the first detailed analysis of signaling pathways and transcriptional mechanisms involved in isoform-specific ECE-1 gene expression.

Antibodies↗
PubMed2000

Coronary artery anomalies and aortic valve morphology in the Syrian hamster.

In the Syrian hamster, anomalies in the origin of the left coronary artery are significantly associated with the bicuspid condition of the aortic valve. In this species, bicuspid aortic valves are expressions of a trait, the variation of which takes the form of a phenotypic continuum, ranging from a tricuspid aortic valve with no commissural fusion to a bicuspid aortic valve with the aortic sinuses located in ventrodorsal orientation and devoid of any raphe. The intermediate stages of the continuum are represented by tricuspid aortic valves with a more or less extensive fusion of the ventral commissure and bicuspid aortic valves with a more or less developed raphe located in the ventral aortic sinus. The present study was designed to decide whether there is a gap between tricuspid and bicuspid aortic valves regarding the incidence of coronary artery anomalies, or whether this incidence varies according to the different tricuspid and bicuspid morphotypes of the continuum. The study was carried out in Syrian hamsters belonging to a single inbred family with a high incidence of tricuspid aortic valves with fusion of the ventral commissure, bicuspid aortic valves, and anomalies in the origin of the left coronary artery, i.e. single right coronary artery ostium in aorta, anomalous origin of the left coronary artery from the pulmonary artery, and anomalous origin of the left coronary artery from the dorsal aortic sinus. The specimens were examined by means of a stereomicroscope and, in several cases, scanning electron microscopy was also used. The relationships between anomalous coronary artery patterns and aortic valve morphologies were tested using a logistic regression model. The results obtained indicate that there is no discontinuity between tricuspid and bicuspid aortic valves regarding the incidence of coronary artery anomalies. The probability of occurrence of anomalous coronary artery patterns increases continuously according to the deviation degree of the aortic valve from its normal (tricuspid) design. The present findings suggest that in the Syrian hamster, the morphogenetic mechanisms involved in the formation of congenital anomalous aortic valves and anomalies in the origin of the left coronary artery, respectively, are strongly related from an aetiological viewpoint.

Animals↗
PubMed1987

Sudden hearing loss and acquired immunodeficiency syndrome.

We have presented a case of a male homosexual with documented acquired immune deficiency syndrome in whom sudden sensorineural hearing loss developed after a series of opportunistic infections and before a massive intracerebral hemorrhage. Two major possible causes of his hearing loss are (1) actual involvement of spiral ganglion or acoustic division of the eighth cranial nerve by HTLV III virus, or (2) cryptococcal meningitis. He ultimately died after a series of neurological complications developed. These complications, which are common in patients with AIDS, include progressive dementia, obtundation, and coma. As the number of patients with AIDS in our society increases over the next 5 years, it will become more important for the otolaryngologist to recognize the complications of this disease that involve the ear, nose, throat, head, and neck. Sudden sensorineural hearing loss is one of these complications. The acquired immune deficiency syndrome, at this point, might best be treated by an approach of preventive medicine. However, such an approach would have far-reaching social and political implications--perhaps more so than in other venereally spread diseases. In the interim, the otolaryngologist-head and neck specialist is required to recognize AIDS as it manifests itself in the head and neck. In this case, sudden-onset sensorineural hearing loss was the otolaryngologic presentation of the AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1972

General surgical pre-admission clinic.

Ninety-nine patients from a non-urgent general surgical waiting list were randomly selected for either direct admission to a hospital bed or review at a preadmission clinic. A considerable reduction in subsequent bed occupancy was shown in the latter group. The findings suggest that more detailed review of patients in the outpatient department would result in the more efficient use of hospital facilities.

Appointments and Schedules↗