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J Palacios

Publications and source records attributed to J Palacios.

At least 55 records · Page 3Linked to original sources
PubMed1995

[A retrospective study of delta F508 mutation in 22 patients operated on for meconium ileus].

Meconium ileus is the earliest clinical manifestation of cystic fibrosis. We report 22 neonates with meconium ileus who had clinical evidence of cystic fibrosis. Patients were categorized as simple with inspissated meconium in the ileum with dilated loops proximally or complicated with volvulus or atresia and/or a perforation resulting in meconium peritonitis. Histopathology of the surgically resected specimens of small bowel revealed lesions typical of cystic fibrosis. Genetic studies were performed on all subjects, this study analyzes the usefulness in the detection of delta F508 mutation in formalin-fixed paraffin-embedded tissues obtained from patients with meconium ileus, ten of whom had the delta F508/delta F508 mutation.

Cystic Fibrosis↗
PubMed1995

Differential spatiotemporal expression of E- and P-cadherin during mouse tooth development.

Changes in E- and P-cadherin (E- and P-CD) expression during embryonic mouse first molar development were analyzed by immunohistochemistry. During the induction and morphogenesis stages (bud, cap and early bell stages), E-CD was expressed in the cells of the invaginating epithelial tooth bud and in the cells of the outer enamel epithelium, stellate reticulum and stratum intermedium, suggesting a role for this molecule in the maintenance of enamel organ architecture. On the other hand, P-CD was strongly expressed in the inner enamel epithelium suggesting its participation in the processes of mesenchymal induction. during the cytodifferentiation stage (late bell stage), E-CD was expressed in polarizing preameloblasts, but cadherin expression was restricted to the basal and apical poles of differentiated secretory ameloblasts, where the zonula adherens type of cell-cell junctions is located. The present study demonstrates for the first time the spatiotemporal expression of cadherins during tooth development and suggests differential and specific roles for E-CD and P-CD during the morphogenesis and cytodifferentiation processes of this organ.

Animals↗
PubMed1994

Lethal Pallister-Killian syndrome: phenotypic similarity with Fryns syndrome.

The Pallister-Killian syndrome is a sporadic multiple congenital anomaly syndrome characterized by "coarse" face, profound mental retardation, and epilepsy. Chromosomes of peripheral lymphocytes are usually normal, but tissue cultures show varying degrees of mosaicism for isochromosome 12p. In babies who die neonatally of severe malformations, including diaphragmatic hernia, and who also have a "coarse" face, acral hypoplasia, and other internal anomalies, Fryns syndrome is more likely to be suspected than Pallister-Killian syndrome, especially if karyotyping is unavailable or if peripheral lymphocytes have a normal chromosome constitution. An initial diagnosis of Fryns syndrome had to be modified in 3 successive newborn infants since chromosome analysis or in situ hybridization with a chromosome 12 probe on kidney tissue demonstrated the mosaic aneuploidy characteristic of Pallister-Killian syndrome. These 3 patients confirm that a similar pattern of malformations can be present in both conditions at birth. It consists of "coarse" face, acral hypoplasia, diaphragmatic hernia, and other defects. Newborn infants who present this phenotype, but lack a conclusively normal chromosome test, may not have Fryns syndrome. A diagnosis of Fryns syndrome should be made carefully to avoid the risk of inappropriate genetic counseling.

Abnormalities, Multiple↗
PubMed1994

E-cadherin expression in basal cell carcinoma.

E-cadherin (E-CD) is a calcium-dependent cell-cell adhesion molecule which is expressed in almost all epithelial tissues. E-CD expression is involved in epidermal morphogenesis and is reduced during tumour progression of mouse epidermal carcinogenesis. It has been suggested that E-CD could play a role as an invasion-suppressor molecule. In the present work we have studied the E-CD expression in 31 patients with basal cell carcinoma (BCC) using an immunohistochemical technique with a monoclonal antibody (HECD-1) specific for human E-CD. E-CD expression was preserved in all specimens of superficial and nodular BCC, and was reduced in 10 of 15 infiltrative BCCs. A heterogeneous distribution of cells with different immunostaining intensity was more frequently observed in specimens of infiltrative BCC. These results suggest that E-CD might be related to the growth pattern and the local aggressive behaviour of BCC, and support the idea that E-CD might play a role as an invasion-suppressor molecule in vivo.

Adult↗
PubMed1994

Mechanisms of entrainment of human common flutter studied with multiple endocardial recordings.

BACKGROUND: The mechanisms of common atrial flutter entrainment have not been directly studied in humans. METHODS AND RESULTS: Endocardial mapping in six cases of common flutter showed large right atrial (RA) reentry circuits. Activation was craniocaudal in the anterolateral right atrium and caudocranial in the septum. The inferior vena cava-tricuspid isthmus (IVC-TV) closed the circuit. The high right atrium was paced at progressively shorter cycle lengths (CLs) in all, and the IVC-TV was paced in three cases. We recorded six to eight simultaneous RA electrograms from septum and anterior wall. Transient entrainment was recognized from all sites by capture of all electrograms at two or more paced CLs, with total or partial preservation of baseline flutter sequence and return to baseline after pacing. Antidromic circuit penetration was documented in five cases during high RA pacing and in one with IVC-TV pacing. Short CLs induced orthodromic conduction delays that resulted in a postpacing pause longer than basal flutter CL. ECG fusion with high RA pacing correlated poorly with antidromic septal penetration. This was related to overlap of orthodromic septal activation with anterior wall activation of the following cycle. Pacing disorganized flutter into a brief irregular rapid rhythm in two cases and atrial fibrillation in one case. In two cases, complete antidromic septal penetration led to sudden flutter interruption, and in another case it led to circuit inversion. CONCLUSIONS: Direct recordings confirm orthodromic and antidromic penetration of flutter circuits by high and low RA pacing. Short CLs modify the circuit. Disorganization is the most common mode of flutter interruption.

Aged↗
PubMed1994

Hormonal receptors, cell proliferation fraction (Ki-67) and c-erbB-2 amplification in breast cancer. Relationship between differentiation degree and axillary lymph node metastases.

In view of the limitations of conventional prognostic factors such as differentiation degree, metastatic lymph nodes, hormonal receptors and others, especially when early lesions are found, additional new markers have been studied, such as gene amplification and cell proliferation index, in order to choose the appropriate treatment. Primary breast carcinoma tumors from 97 patients were examined for differentiation degree, metastatic lymph nodes, hormonal receptors, c-erbB-2 amplification and cell proliferation index (Ki-67). A negative relationship with hormonal receptors and c-erbB-2 amplification, Ki-67 and differentiation degree was found, whereas the relationship between c-erbB-2, Ki-67 and differentiation degree was positive. No relationship was found between these factors and metastatic lymph nodes. The concurrence of high cell proliferation index, c-erbB-2 amplification and negative hormonal receptor presence would indicate a subpopulation with a high risk of recurrence. But a larger survival study is necessary to correlate these factors with clinical outcome.

Adult↗
PubMed1994

Detection of delta F508 cystic fibrosis mutation by polymerase chain reaction from old paraffin-embedded tissues: a retrospective autopsy study.

This study analyzes the usefulness of the polymerase chain reaction technique in the detection of delta F508 mutation in 11- to 25-yr-old formalin-fixed paraffin-embedded tissues obtained from the autopsy of 38 cystic fibrosis patients (nine with meconium ileus). Two different pairs of oligonucleotide primers were used: C16 B/C16 D that amplify 98 and/or 95 bp and FQ1/FQ2 that amplify 50 and/or 47 bp. After two independent rounds of polymerase chain reactions with the two sets of primers, amplification products were obtained in 67.5% of the cases when using C16 B/C16 D primers and in all cases when using FQ1/FQ2 primers. Fifty percent of the chromosomes analyzed in the 29 patients without meconium ileus had the delta F508 mutation, which was present in 13 heterozygous and 8 homozygous patients. The remaining eight cystic fibrosis patients did not carry that mutation. These results are similar to those reported in cystic fibrosis patients from Spain. In the meconium ileus group, we found a higher than expected proportion of delta F508 mutation; all patients showed the delta F508 mutation in at least one chromosome, seven patients (77.8%) being homozygous and two (22.2%) heterozygous. Present results indicate that delta F508 mutation can be detected by polymerase chain reaction in old paraffin-embedded tissues when appropriate primers are used.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1993

Severe axial anomalies in the oculo-auriculo-vertebral (Goldenhar) complex.

We have studied 4 infants with oculo-auriculo-vertebral (OAV) complex or Goldenhar "syndrome" who also had severe axial anomalies, including multiple vertebral segmentation errors affecting the thoracic and the lumbar spine. One of them presented a previously unreported pattern of vertebral and rib anomalies similar to spondylocostal dysostosis. Three patients had twins, and all 4 patients had other associated non-skeletal malformations which affected the midline, i.e., cleft lip and palate, esophageal atresia with tracheoesophageal fistula, and ventricular septal defect. The broad extent of the axial anomalies, the association with midline defects and twinning, and the combination in the same patient of two distinct conditions support the concept that OAV complex is a polytopic developmental field defect arising during blastogenesis.

Abnormalities, Multiple↗
PubMed1993

Decrease in thyrocalcitonin-containing cells and analysis of other congenital anomalies in 11 patients with DiGeorge anomaly.

Experimental studies have demonstrated that the DiGeorge anomaly is due to cranial neural crest abnormalities. In the present study, the quantitation of thyrocalcitonin immunoreactive cells (C-cells) has been used to evaluate whether cells derived from the cranial neural crest are or are not present in normal proportions in patients with this anomaly. Thyroid sections from 11 such patients and 11 control patients were studied immunohistochemically at autopsy in order to determine the number and distribution of thyrocalcitonin-containing cells. Patients with DiGeorge anomaly showed thymic and parathyroid aplasia/hypoplasia and cardiovascular defects, such as type B interrupted aortic arch, truncus arteriosus and tetralogy of Fallot. Other associated defects were alobar holoprosencephaly and meningocele (previously unreported defects in this anomaly), arhinencephaly, renal cystic dysplasia, ureterohydronephrosis, esophageal atresia with tracheoesophageal fistula, and cleft lip and palate. The volume density of C-cells (1.187%) and the mean number of C-cells per follicle (1.42) was significantly lower in patients with DiGeorge anomaly than in control patients (3.475% and 2.367, respectively). These results indicate a decrease in cells derived from the neural crest in patients with DiGeorge anomaly, and support the hypothesis of a neural crest disturbance as the pathogenetic factor responsible for this anomaly.

Calcitonin↗
PubMed1993

Decrease in calcitonin-containing cells in truncus arteriosus.

Experimental studies in chick embryos have demonstrated that truncus arteriosus (TA), a form of conotruncal cardiac defect, is due to abnormalities in the cranial neural crest. However, no data are available to support this hypothesis in humans with isolated TA. In the present study, the assessment of calcitonin immunoreactive cells (C-cells) has been employed to evaluate whether or not the proportion of thyroid cells derived from the cranial neural crest is normal in patients with isolated TA. Thyroid sections from 15 such patients in which no other extracardiac malformations were neither clinically nor pathologically found, and from 11 control age-matched patients were studied immunohistochemically at autopsy in order to determine the number and distribution of calcitonin-containing cells. The volume density of C-cells (0.888%) and the number of C-cells per follicle (0.991) was significantly lower in patients with TA than in control patients (3.475%, and 2.367, respectively). The decrease of neural crest-derived cells in the thyroid of patients with "isolated" TA documents more extent abnormalities than clinically suspected and supports the hypothesis of neural crest disturbance as the pathogenetic factor responsible for this heart malformation.

Calcitonin↗
PubMed1993

Immunohistochemistry of the human ductus epididymis.

Our objective was to characterize epithelial cells, lamina propria, and sites of estrogen coupling in the caput, corpus, and cauda regions of the human epididymis using antibodies to cytokeratin types; epithelial membrane antigen; laminin; type IV collagen; vimentin; desmin-, and estradiol-receptor-related protein; and immuno-histochemical techniques. Principal cells immunostain by both AE1/AE3 antibodies (keratins 1-8, 10, 13-15, and 19) and anti-pan-keratin antibodies (keratin 5, 6, and 8). Immunoreactions to both anti-keratin antibodies increase from the caput to the cauda epididymis. The principal cells only immunostained by anti-keratin 19 antibodies in the cauda and showed no reaction to keratins 10 and 11. Basal cells and apical cells immunoreact to anti-AE1/AE3, antipankeratin, and antikeratin 19 antibodies, but not to antikeratin 10 and 11 antibodies, in all three epididymal regions. The principal cells immunoreact with epithelial membrane antigen antibodies in the stereocilia and subjacent cytoplasm. This immunostaining decreased from the caput to the cauda. Antivimentin antibodies stained the apical cytoplasm of principal cells and limited areas of both principal cells and basal cells. This immunoreaction decreased from the caput to cauda. Apical cells immunostained in the three regions. Immunoreaction to ER-D5 was moderate in the principal cells, basal cells, apical cells, and muscular coat cells in the cauda. The apical cells immunostained in the three regions. Antilaminin antibodies stained the epithelial basement membrane in the three regions. Type IV collagen was detected in the basement membrane as well as around the muscular coat cells in the three regions. Immunoreaction to desmin was intense in the muscular coat cells in the three regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Signet-ring stromal tumor of the ovary: a histochemical, immunohistochemical and ultrastructural study.

We report a signet-ring stromal tumour found in the ovary of a 50-year-old woman. The solid tumour was composed of spindle and round cells which stained with vimentin and some round cells were vacuolated and had the appearance of signet-ring cells. The vacuoles were negative with periodic acid-Schiff, with and without diastase digestion, with alcian blue, Sudan III, alpha-1-antitrypsin and alpha-fetoprotein stains. Ultrastructurally, they were membrane bound and contained scantly flocculent material. Some neoplastic cells contained intracytoplasmic eosinophilic globules which were positive with alpha-1-antitrypsin. Signet-ring stromal tumour is a benign, morphologically distinctive type of ovarian stromal tumour, which may present problems in differential diagnosis with other stromal and non stromal ovarian neoplasms.

Adenocarcinoma, Mucinous↗
PubMed1993

Enzymohistochemical and immunohistochemical study of the human efferent ducts.

An enzymohistochemical and immunohistochemical study of the efferent ducts was performed in normal adult men. The epithelium consists of two types of columnar cells: principal cells (PCs) and ciliated cells (CCs), and is surrounded by a lamina propria (LP) with cells arranged circularly (LPCs). Enzymohistochemical study revealed more intense activity of succinic dehydrogenase, NADP, and ATPase in the CCs than in the PCs. The LPCs also showed an intense reaction for NADP and ATPase. Acid phosphatase activity was only intense in the apical cytoplasm of PCs. Immunohistochemical study revealed that antibodies to oestradiol receptor-related protein (ER-D5) immunostained the PCs and CCs intensely and the LPCs weakly. AE1/AE3 antibodies (which stain keratins nos. 1-8 and 14, 15 and 19) immunostained the PCs intensely, but was negative in both CCs and LPCs. Antibodies to keratin Ks.4.62 (which stain keratin no. 19) immunostained PCs and CCs but not LPCs. Epithelial membrane antigen antibodies (EMA) immunostained the adluminal surface and apical cytoplasm of PCs. Anti-vimentin antibodies immunostained the cytoplasm of PCs and CCs weakly as well as isolated cells in the LP. Antibodies to desmin immunostained most LPCs. Antibodies to collagen IV immunostained the basal lamina and many extracellular spaces in the LP, mainly around the LPCs. The differences between the enzymohistochemical and immunohistochemical patterns of the efferent ducts and those of the epididymis may help to explain functional differences along the epididymis.

Adult↗
PubMed1993

Structure functional expression and spatial distribution of a cloned cDNA encoding a rat 5-HT1D-like receptor.

Using polymerase chain reaction (PCR) a complementary DNA (cDNA) encoding a 5-hydroxytryptamine (5-HT) receptor was isolated from rat forebrain. The amplified cDNA specifies an open reading frame of 374 amino acids comprising seven putative transmembrane regions. Expression of the cloned cDNA in human embryonic kidney cells (HEK 293) was used to establish the pharmacological profile of the encoded receptor polypeptide. Membranes containing the cloned receptor showed high affinity binding of [3H]-5-HT. Competition binding experiments with a variety of serotonin receptor ligands displayed a rank order of affinities corresponding to a 5-HT1D subtype: 5-CT > 5-HT = metergoline > CGS 12066 > methysergide > sumatriptan > mianserin = (-)alpha-Me-5-HT = yohimbine > 8-OH-DPAT > or = rauwolscine > spiperone > DOI > propranolol > or = 2-Me-5-HT > or = ICS 205930. Ketanserin and ritanserin displaced [3H]-5-HT-binding in a biphasic manner. In situ hybridization revealed highest expression of the corresponding mRNA in the pyramidal layer of the olfactory tubercle and the nucleus caudatus and accumbens.

Amino Acid Sequence↗
PubMed1993

Immunohistochemical and semiquantitative study of the apical mitochondria-rich cells of the human prepubertal and adult epididymis.

An immunohistochemical and semiquantitative study of the apical mitochondria-rich cells (AMRC) in the caput, corpus and cauda of the human epididymis from the fetal period to adulthood was performed on autopsy specimens from normal males without testicular or associated pathology. The immunohistochemical pattern of AMRC differed from that of the principal cells (PC). AMRC showed a more intense immunoreaction to several keratin types (AE1 and AE3 keratin complexes, and keratins 18 and 19) and to oestradiol-related protein receptors than did PC. In addition, immunostaining with antibodies to epithelial membrane antigen was intense in PC and weak in AMRC. Two immunohistochemical types of basal cells were observed: one was similar to the AMRC and the other to PC. PC and AMRC were already present in fetuses of 24-27 wk gestation. Basal cells were only occasionally observed at this age, but became much more numerous in the 28-33 wk fetuses. No changes in the immunohistochemical patterns of any of these cell types were found during infancy and adulthood. The numbers of PC per unit length of basement membrane were very similar in the 3 epididymal regions and at all ages studied. In all age groups, the number of AMRC decreased from caput to cauda epididymis. In the caput and corpus, the number of AMRC rose during the fetal period and the first 6 months after birth and thereafter decreased progressively during infancy and adulthood.

Adult↗
PubMed1993

Correlation of E-cadherin expression with differentiation grade and histological type in breast carcinoma.

Recently, a correlation has been suggested between a loss of E-cadherin (E-CD) and increased invasiveness of neoplastic cells. In this study, E-CD expression in breast cancer was investigated using an affinity-purified antibody (ECCD-2) in an immunoenzymatic (avidin-biotin-alkaline phosphatase) test. Intensity and extension of E-CD immunoreactivity were evaluated in 61 breast carcinomas and correlated with their histological type and grade, nodal involvement, and hormonal receptor status. Histological types were infiltrating ductal carcinoma of no special type (n = 54) and infiltrating lobular carcinoma (n = 7). All infiltrating ductal carcinomas of no special type except two grade 3 carcinomas showed positive immunoreactivity that was variable among different cases. Grade 1 breast carcinomas (n = 10) showed greater immunoreactivity than grade 2 (n = 25) and grade 3 (n = 19) carcinomas. E-CD immunoreactivity correlated positively with the degree of tubular formation and inversely with the mitoses number. None of the infiltrating lobular carcinomas expressed E-CD in their infiltrating cells, whereas they showed only weak immunostains in areas of atypical lobular hyperplasia and lobular carcinoma in situ. These results indicate that E-CD expression correlates with histological type and grade in breast carcinomas.

Breast Neoplasms↗
PubMed1992

Nucleotide sequence and organization of an H2-uptake gene cluster from Rhizobium leguminosarum bv. viciae containing a rubredoxin-like gene and four additional open reading frames.

The nucleotide sequence of a 3.2 kb region following the hydrogenase structural operon (hupSLCDEF) in the H2-uptake gene cluster from Rhizobium leguminosarum by viciae strain 128C53 has been determined. Five closely linked genes encoding products of 16.3 (HupG), 30.5 (HupH), 8.0 (HupI), 18.4 (HupJ) and 38.7 (HupK) kDa were identified 166 bp downstream from hupF. Transposon insertions into hupG, hupH, hupJ and hupK suppress the H2-oxidizing capability of the wild-type strain. The amino acid sequence deduced from hupI contains two Cys-X-X-Cys motifs, characteristic of rubredoxins, separated by 29 amino acid residues showing strong sequence homology with other bacterial rubredoxins. The amino acid-derived sequence from hupG and hupH showed homology to products from genes hyaE and hyaF of the operon encoding hydrogenase 1 from Escherichia coli, and hupJ and hupK were related to open reading frames identified in Rhodobacter capsulatus and Azotobacter vinelandii hydrogenase gene clusters. An involvement of the hupGHIJK gene cluster in redox reactions related to hydrogenase synthesis or activity is predicted on the basis of the function as electron carrier attributed to rubredoxin.

Amino Acid Sequence↗