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C Ferrer

Publications and source records attributed to C Ferrer.

At least 37 records · Page 2Linked to original sources
PubMed1999

Ultrastructural and biochemical analysis of epidermal xanthophores and dermal chromatophores of the teleost Sparus aurata.

We have studied the pigmentary system of the teleost Sparus aurata skin by electron microscopy and chromatographic analysis. Under electron microscopy, we found the dermis to contain the three major types of recognized chromatophores: melanophores, xanthophores and iridophores. Melanophores were more abundant in the dorsal region, whereas the iridophores were more abundant in the ventral region. The most important discovery was that of epidermal xanthophores. Epidermal xanthophores were the only chromatophores in the epidermis, something only found in S aurata and in a teleost species living in the Antartic sea. In contrast, the biochemical analysis did not establish any special characteristics: we found pteridine and flavin pigments located mostly in the pigmented dorsal region. Riboflavin and pterin were two of the most abundant coloured pigment types, but other colourless pigments such as xanthopterin and isoxanthopterin were also detected.

Animals↗
PubMed1999

Relevance of aromatic residues in transmembrane segments V to VII for binding of peptide and nonpeptide antagonists to the human tachykinin NK(2) receptor.

We used membranes from Chinese hamster ovary cells stably transfected with the human tachykinin NK(2) receptor, either wild-type or mutated, at four aromatic residues (His(198), Tyr(266), Phe(270), Tyr(289)) located in transmembrane segments V to VII, to assess the role of these residues in the binding of natural tachykinins and peptide and nonpeptide antagonists. Three radioligands, the agonist [(125)I]neurokinin A (NKA), the peptide antagonist [(3)H]MEN 11420, and the nonpeptide antagonist [(3)H]SR 48968 bound to the wild-type receptor with high affinity (K(d) = 2.4 nM, 0.3 nM, and 4.0 nM, respectively). Four of the six mutant receptors tested retained high affinity for at least one of the radioligands. H(198)A mutation abrogated the binding of NKA but not that of MEN 11420 or SR 48968 (K(d) = 4.8 and 11.5 nM, respectively); Y(266)F mutation abrogated the binding of MEN 11420 but not that of NKA or SR 48968 (K(d) = 2.8 nM and 1.2 nM, respectively); F(270)A mutation abrogated the binding of both NKA and MEN 11420 but not that of SR 48968 (K(d) = 1.6 nM); Y(289)F mutation abrogated the binding of SR 48968 but not that of NKA and MEN 11420 (K(d) = 2.0 and 2.9 nM, respectively). Y(266)A and Y(289)A mutations abrogated the binding of all radioligands. Among the unlabeled antagonists, the affinity of the nonpeptide GR 159897, at variance with SR 48968, resulted heavily compromised by H(198)A and Y(266)F mutations; the peptide antagonists R396 and MEN 10376 essentially followed the binding profile of NKA, but R396 showed markedly increased affinity for the Y(289)F mutant receptor. Taken together, these results indicate that different, partially overlapping sets of sites may be involved in the binding of agonists and diverse antagonists to the human tachykinin NK(2) receptor.

Animals↗
PubMed1998

The melanogenic system of Xenopus laevis.

Melanin pigments in lower vertebrates are often found in locations other than the skin, thus forming an extracutaneous pigmentary system of unknown function. The cellular and biochemical structure of this system is still poorly characterized. This paper deals with the ultrastructural and biochemical features of the melanogenic system of Xenopus laevis. Melanin containing cells were identified in the dorsal and ventral skin, and in the lung, spleen, liver and connective tissue surrounding blood vessels. The pigment cells in the skin and the lungs appeared to be typical melanocytes. The spleen contained isolated melanocyte-like cells, but most of the pigment cells present in this organ were associated with melanomacrophage centers. Conversely, the liver appeared devoid of melanocytes and only displayed melanomacrophage centers. Tyrosinase activity was found in all pigment-containing organs except the liver. All organs containing tyrosinase activity also displayed melanin formation potential from L-tyrosine. Therefore, tyrosine hydroxylase and melanin formation activities could be detected only in those organs containing typical melanocytes but not in locations such as the liver, where only melanomacrophages centers were found.

Animals↗
PubMed1997

Giant-cell chondrodysplasia in a male infant with clinical and radiological findings resembling the Piepkorn type of lethal osteochondrodysplasia.

We report on a patient whose clinical, radiologic, and histopathologic findings are compatible with the Piepkorn type of lethal short-limb osteochondrodysplasia, but who also showed multinucleated giant chondrocytes in cartilage. Multinucleated giant cells are an unusual finding in osteochondrodysplasias, having been reported in atelosteogenesis type I and boomerang dysplasia. This uncommon histopathologic finding and the clinical and radiographic findings strongly support the diagnosis of boomerang dysplasia in the present patient. Our patient supports the previously suggested existence of an entity including atelosteogenesis and boomerang dysplasia. If this is so, the current patient and that described by Piepkorn et al. [1977: Teratology 16:345-350] could represent the most severe clinical expression of that condition.

Cartilage↗
PubMed1997

Osmotically induced response in representatives of halophilic prokaryotes: the bacterium Halomonas elongata and the archaeon Haloferax volcanii.

Haloferax volcanii and Halomonas elongata have been selected as representatives of halophilic Archaea and Bacteria, respectively, to analyze the responses to various osmolarities at the protein synthesis level. We have identified a set of high-salt-related proteins (39, 24, 20, and 15.5 kDa in H. elongata; 70, 68, 48, and 16 kDa in H. volcanii) whose synthesis rates increased with increasing salinities. A different set of proteins (60, 42, 15, and 6 kDa for H. elongata; 63, 44, 34, 18, 17, and 6 kDa for H. volcanii), some unique for low salinities, was induced under low-salt conditions. For both organisms, and especially for the haloarchaeon, adaptation to low-salt conditions involved a stronger and more specific response than adaptation to high-salt conditions, indicating that unique mechanisms may have evolved for low-salinity adaptation. In the case of H. volcanii, proteins with a typical transient response to osmotic shock, induced by both hypo- and hyperosmotic conditions, probably corresponding to described heat shock proteins and showing the characteristics of general stress proteins, have also been identified. Cell recovery after a shift to low salinities was immediate in both organisms. In contrast, adaptation to higher salinities in both cases involved a lag period during which growth and general protein synthesis were halted, although the high-salt-related proteins were induced rapidly. In H. volcanii, this lag period corresponded exactly to the time needed for cells to accumulate adequate intracellular potassium concentrations, while extrusion of potassium after the down-shift was immediate. Thus, reaching osmotic balance must be the main limiting factor for recovery of cell functions after the variation in salinity.

Adaptation, Physiological↗
PubMed1997

[Anatomic features of the middle ear in the gerbil. Scanning electronic microscopic study].

The surgical anatomy of the middle ear was studied in 20 adult gerbils (Meriones unguiculatus) by microdissection and scanning electron microscopy. The most significant finding was a well pneumatized tympanic bulla, which facilitated the identification of useful anatomical landmarks for middle and inner ear dissection. The typical features of middle ear structures in the gerbil are described.

Animals↗
PubMed1997

[Evaluation of impaction on bone nail and bone plate of the pertrochanteric fracture].

PURPOSE OF THE STUDY: Impaction in pertrochanteric fracture sites is a well known phenomenon; the screw-plate system is designed to stabilise the fracture. Although easier to use, the risk with the nail-plate system is postoperative penetration of the nail into the joint. The present study was conducted to determine the exact conditions of the impaction, and to identify possible ways to improve the nail-plate system. MATERIAL-METHOD: The study included 129 cases of pertrochanteric fracture, excluding sub-trochanteric fractures. All fractures were fixed with a 130 degrees angulated nail-plate. In all cases, consolidation was uneventful after 8 to a 12 weeks. The anatomical type of fracture, i.e. stable or unstable, was determined according to the size of the intermediary fragment, including the trochanter minor. The displacement was measured as the difference between the length of the nail and the length of the femoral head and neck measured along the axis of the femoral neck. The parameters examined were: fracture stability degree, bony mineralisation (Singh Index), nail length, femoral neck, length nail position in the femoral head, and above all, fracture reduction. All these parameters were computerised and compared using Stat View statistics software. RESULTS: Impaction was observed in 43 per cent of cases. Among these, 25 per cent were rated as slight (1 to 5 mm), 18 per cent as moderate (over 5 mm) and 9 per cent as marked (10 to 25 mm). Impaction was associated with demineralisation of the bone tissue (p = 0.001). The anatomical classification of the fracture was not a determining factor (p = 0.19), as marked displacements were also recorded in stable fractures. A posterior and inferior position of the intramedullary nail in the femoral head is one of displacement determining factors (p = 0.004, two-sided 1 test). Valgus over-correction is the most important factor, especially when it is associated with bony demineralisation (p = 0.02) and an inadequately centred intramedullary pin (p = 0.02). Shorter the femoral neck, and shorter the nail, greater was the frequency of nail articular penetration. DISCUSSION: The risk of articular penetration therefore reaches 15 per cent in petrochanteric fractures repaired with a nail plate, set at an angle of 130 degrees. A short neck, a cervicodiaphyseal angle superior to 140 degrees, and demineralisation are the three determining parameters. Stable or unstable fracture has in fact little effect on displacement incidence, and therefore does not, on its own, warrant the use of a prosthesis in comminuted fractures. The authors compared their results to literature on progressive sliding system: the incidence of complications associated with this type of fracture treatment is identical, but the determining parameters are different. CONCLUSION: The study shows that the nail-plate is efficient and provides simple and solid fracture fixation. However, this osteosynthesis material needs to be modified in order to improve its fixation in the femoral head.

Adult↗
PubMed1996

Expression and characterization of a mouse/human chimeric antibody specific for EGF receptor.

Murine antibodies which recognize the epidermal growth factor receptor (EGF-r) are good candidates for therapy and diagnosis of tumors overexpressing this receptor. Here we report the isolation of the variable regions from a murine monoclonal antibody anti-EGF-r (Mint5), the procedure to obtain the mouse/human chimeric antibody (chMint5) and its expression in COS, NS0 and CHO cells. The approach followed to construct chMint5 is based on the use of consensus primers specific for the ends of the variable regions. The sequence imposed by the primers did not affect the targeting potential of the antibody. In fact, the affinity of the chimeric antibody for EGF-r was nearly the same as that of the parental murine antibody. Based on previous in vitro and in vivo animal studies. Mint5 was shown to be a good candidate for the targeting of EGF-r overexpressing tumours. chMint5 is expected to be less immunogenic than murine antibody and therefore, could be useful for human treatment.

Amino Acid Sequence↗
PubMed1996

The effects of interleukin-1 receptor antagonist protein (IRAP) infusion following spinal cord transection in rats.

A laminectomy was performed at the T5-T6 vertebral level in adult, male, Sprague-Dawley rats and the spinal cord transected with a scalpel. A group of sham animals was subjected to the same surgery without the transection step. A group of unhandled control rats was also included. A subgroup of transected animals received a subcutaneous osmotic minipump that dispensed IL-1 receptor antagonist protein (IRAP) at the transection site for 7 consecutive days. Another transected subgroup received a minipump that infused the vehicle only. IRAP-treated rats displayed a significant reduction in body temperature (p < 0.05) compared with vehicle-treated rats. The IRAP-treated rats were also less active when assessed for locomotor behavior using an HVS computerized tracking system (p < 0.01). IRAP treatment had no effect on serum corticosterone, beta-endorphin levels, Con A, PHA, or LPS-induced splenocyte mitogenesis when compared with vehicle-treated animals. However, half of the IRAP-treated animals exhibited a substantive reduction in the number of reactive astrocytes near the transection site, suggesting a possible effect of IRAP on astrocyte activation.

Animals↗
PubMed1996

Differentially transcribed regions of Haloferax volcanii genome depending on the medium salinity.

To identify genomic regions involved in osmoregulation in the extremely halophilic archaeon Haloferax volcanii, we used a technique which involves hybridization of cDNAs obtained at different salinities against a cosmid library of the organism. Both low and high salt concentrations trigger differential expression; however, adaptation to low salinities seems to elicit a wider response. The presence of a large domain within the largest of the megaplasmids with a strong response to low salt concentrations is noteworthy.

Blotting, Northern↗
PubMed1996

[Skin lesions in epidemic Kaposi's sarcoma (AIDS): local control assessment and esthetic results of a schedule of superficial radiotherapy].

This prospective study was undertaken to evaluate the clinical response of 51 cutaneous lesions of epidemic Kaposi sarcoma in patients with AIDS (EKS/AIDS), obtained with the use of a scheme of superficial radiotherapy (3 Gy/fraction, three fractions weekly up to a total dose of 30 Gy). The mean follow-up time was 9.3 months and the mean time to progression of EKS/AIDS disease was 7-8 months. The initial clinical parameters (pain, size, edema, and esthetics) of each cutaneous lesion were compared with those obtained after one week, one month and three months of therapy. An objective pain improvement was observed in 72% of early lesions and with statistic significance (after one week p = 0.003). After one month of therapy a decrease in lesion size, edema, and esthetic improvement was observed in 78%, 71% and 77%, respectively. Although the evolution and prognosis of EKS/AIDS remains unchanged, it indeed provided palliation, with improvement of local control and esthetics, which together with the simplicity of its application and absence of untoward effects render this radiotherapy technique a very useful indication.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Long stretches of short tandem repeats are present in the largest replicons of the Archaea Haloferax mediterranei and Haloferax volcanii and could be involved in replicon partitioning.

We report the presence of long stretches of tandem repeats in the genome of the halophilic Archaea Haloferax mediterranei and Haloferax volcanii. A 30 bp sequence with dyad symmetry (including 5 bp inverted repeats) was repeated in tandem, interspersed with 33-39 bp unique sequences. This structure extends for long stretches--1.4 kb at one location in H. mediterranei chromosome and about 3 kb in the H. volcanii chromosome. The tandem repeats (designated TREPs) show a similar distribution in both organisms, appearing once or twice in the H. volcanii and H. mediterranei chromosomes, and once in the largest, probably essential megaplasmid of each organism but not in the smaller replicons. Sequencing of the structures in both H. volcanii replicons revealed an extremely high sequence conservation in both replicons within the species, as well as in the different organisms. Homologous sequences have also been found in other more distantly related halophilic members of the Archaea. Transformation of H. volcanii with a recombinant plasmid containing a 1.1 kb fragment of the TREPs produced significant alterations in the host cells, particularly in terms of cell viability. The introduction of extra copies of TREPs within the vector significantly alters the distribution of the genome among the daughter cells, as observed by DAPI staining. Although the precise biological role cannot be completely ascertained, all the data conform with the tandem repeats being involved in replicon partitioning in halobacteria.

Base Sequence↗
PubMed1995

Melanocytes in the stria vascularis and vestibular labyrinth of the Mongolian gerbil (Meriones unguiculatus).

Inner ear melanocytes are mainly present in the cochlea, vestibular organ, and endolymphatic sac, but their exact biological function has not been determined. In this investigation, we study the pigment cells in the membranous labyrinth of the gerbil. The inner ear melanocytes of M. unguiculatus show an irregular dendritic shape with cytoplasmic processes. These cells are disposed following the distribution of strial marginal and vestibular dark cells that have an important metabolic activity. Gerbil inner ear melanocytes are characterized by the presence of melanosomes, which are homogeneously dense organelles, of variable size and shape, that are surrounded by a membrane. In these cells, the Golgi apparatus plays a important role in melanin synthesis. When melanocytes were incubated in L-DOPA solution, the vesicles and cisterns of the Golgi apparatus exhibited a positive tyrosinase reaction. An interesting observation is the relation between melanocytes and inner ear capillaries. Sometimes, near to sensory vestibular areas, the melanocytes were in contact with Schwann cells and with myelinated fibres of vestibular nerve. The ultrastructural findings of this investigation are consistent with the hypothesis that melanocytes may have functional significance in the inner ear.

Animals↗
PubMed1995

Cutaneous phaeohyphomycosis caused by Alternaria longipes in an immunosuppressed patient.

Alternaria longipes was reported as the agent of a cutaneous infection in a patient with a neoplastic disease. The fungus has not been reported previously as causing disease in humans. It was distinguished by its rather small conidia with smooth or slightly verruculose walls and a pale brown beak which rarely extended into a secondary conidiophore. In vitro inhibitory activities of amphotericin B, ketoconazole, itraconazole, and miconazole were shown.

Alternaria↗
PubMed1995

Right-sided bacterial endocarditis due to Flavobacterium odoratum in a patient on chronic hemodialysis.

Bacterial endocarditis, particularly involving the left side, has been shown to occur in patients in regular hemodialysis. We report a case of right-sided endocarditis characterized by a very torpid evolution. Although the diagnosis was suspected early in the course, confirmation was obtained 2 months after the onset. Flavobacterium odoratum was identified in the fourth month of evolution and only after multiple blood cultures had been obtained. We believe the very low infectivity of F. odoratum and its very slow growth in culture media prevented an early diagnosis.

Endocarditis, Bacterial↗
PubMed1994

Stereotactic radiosurgery of deeply seated low grade gliomas.

The authors report the results of a series of 16 cases of low-grade gliomas in whom radiosurgery was performed. This series started in 1977. All the tumours received a single radiosurgical session (with a mean dose of 21.7 Gy, 5-10 mm. collimator; one patient received two sessions and in another patient two different targets were irradiated in the same session). Prior to radiosurgery, six patients received conventional external fractionated radiotherapy, with two lateral fields of up to 10 x 10 cm. and a mean dose of 55.1 Gy and another six patients with tumours less than 5 cm. in diameter, received stereotactic radiotherapy using four fields of up to 5 x 5 cm. and a mean dose of 53.1 Gy. In both cases, conventional fractionation was used, giving a dose of 1.8 to 2 Gy/day. The tumour disappeared in 8 cases (50%) and shunk or ceased its growth in 5 additional cases (31%). In 3 cases of brainstem gliomas in which the clinical condition was previously very poor there was no evolutional change and the patients eventually died. We conclude that radiosurgery is effective in the treatment of deeply seated low-grade gliomas, where it may become the treatment of choice in the absence of other more definitive choices.

Adolescent↗
PubMed1994

[Infection by the human immunodeficiency virus in the elderly. Presentation of 13 cases].

The aim of this paper is to describe the clinical characteristics of the infection by the human immunodeficiency virus (HIV) in 13 aged patients with more than 60 years of age. In all the cases, the first clinical manifestation causing the visit to the doctor was an opportunistic infection with criteria of acquired immunodeficiency syndrome (AIDS), standing out the low CD4 rate in all the patients, a delay in the diagnosis and a short survival.

Aged↗