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Biomedical subjects

S Romero

Publications and source records attributed to S Romero.

At least 73 records · Page 4Linked to original sources
PubMed1990

Behavior of rabbit dental tissues in heterospecific association with embryonic quail ectoderm.

The behavior of dental tissues from the rabbit, Oryctolagus cuniculus, in association with epithelium from the quail, Coturnix coturnix japonica, has been examined. Adult and embryo rabbits were employed in this study. Dental papillae from teeth at the cap stage from rabbit embryos and dental pulp from adult rabbits were isolated surgically and recombined with skin ectoderm from 72-hour-old quail embryos. The recombined tissues were cultured for 48 hours on semi-solid medium and subsequently removed and placed on chorio-allantoic membranes of 7-day-old chick embryos. Control cultures (dental pulp, dental papillae, and quail ectoderm) showed regression, atrophy, or differentiation according to the phenotype of the tissue. After 8 days in explant culture, heterologous recombinants composed of dental papillae and flank skin ectoderm from quail embryos developed differentiated chimeric tooth structures. It was unclear whether or not enamel was being secreted. The fact that the interactions between the enamel epithelium and the dental papillae are reciprocal is well known. The differentiation of odontoblasts can only occur in the presence of an enamel organ. Thus, the quail epithelium must have been induced to become an enamel organ, the lack of enamel proteins notwithstanding. Apical pulp and root pulp from adult rabbits plus quail ectoderm showed a high degree of regression and atrophy. At around 15 days of gestation, the rabbit dental papillae at the cap stage have already acquired odontogenic potential. By contrast, under the same experimental conditions, the dental pulp from continuous-growth teeth from adult rabbits did not show odontogenic potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Long-term treatment with Madopar HBS in parkinsonians with fluctuations.

1. Of 22 parkinsonians with fluctuations under long-dating dopatherapy in whom standard Madopar was substituted by the HBS form, 16 who performed the trial longer than 1 year were particularly studied to evaluate some parameters of this long-term follow-up (30-36 months). 2. The outstanding beneficial effects were an enhancement of the antiparkinsonian response, improvement or disappearance of motor oscillations, longer "on" periods, less severe "off" periods, and a more sustained nocturnal antiparkinsonian effect with a reduction of dystonias and pain at night and decreased or absent early morning parkinsonism. 3. The decrease or disappearance of dystonia was observed since the early stages of the trial and can be explained by the more sustained dopaminergic effect. 4. Surprisingly, dyskinesias also decreased in spite of the higher dopaminergic effect. The avoidance of sharp and repeated plasmatic peaks and the lower levels of L-dopa under HBS could explain this phenomenon. 5. The negative aspects of Madopar HBS are a lower bioavailability that means a dosage increase and a longer latency for the therapeutic response in the morning. 6. The dosage increase went up by 80% to 100% in relation to standard Madopar during the long-term treatment. 7. As Madopar HBS is a sustained release preparation, we had to increase the initially reduced the number of intakes, again in order to obtain better results. In the most severe cases with poor or absent response, benefits were achieved only when administering the HBS intake every hour.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Rabbit's middle ear as a practical model for the initiation in otosurgery].

The rabbit's head is a practical model which make easy at beginning the practical for the knowledge and the use of specific instruments in ear surgery, as well as the handling of the microscope. The raw material is cheap and its obtention is easy. The grip of the rabbit's temporal bone facilitates a lot preparation of the human temporal bone, nowadays harder to get. In our Laboratory of otologic dissection the first resident's contact with the ear surgery, since years, is through the rabbit's head. The experience so gained by young specialists is excellent.

Animals↗
PubMed1989

[Diagnostic usefulness of neurospecific enolase determination in pleural fluid].

To investigate the diagnostic usefulness of the measurement of neurospecific enolase (NSE) in pleural fluid 116 consecutive patients with pleural effusion were prospectively evaluated. In 95 of them, carcinoembryonic antigen (CEA) was also measured for comparative purposes. The habit of smoking did not apparently influence the NSE levels. In the 43 malignant effusions the mean value of NSE (25.0 +/- 27.4) was significantly higher (p less than 0.001) than in benign effusions (8.7 +/- 7.1). The values above 12 ng/ml had a sensitivity of 51% for malignancy, with a specificity of only 74%. The specific sensitivity of NSE was lower than that of CEA; neither individually nor as a whole these markers modified the diagnostic yield of cytology (67%). The mean value of NSE in tuberculous pleural effusions (14.4 +/- 8.3), different from that found in malignancies (p less than 0.05), was significantly higher (p less than 0.001) than that found in other benign diseases (6.2 +/- 4.7). The results of this study demonstrate the nonspecific character of an increased level of NSE, and the low diagnostic yield of this enzyme as a pleural tumour marker.

Adolescent↗
PubMed1989

Combination of selegiline and controlled release levodopa in the treatment of fluctuations of clinical disability in parkinsonian patients.

Thirteen parkinsonians with a long duration of the disease and long-term dopa therapy, seven of them showing severe on-off oscillations and 6 an "end-of-dose impairment", were treated with a controlled release (HBS) preparation of L-DOPA/benserazide for more than 3 years. Thereafter, selegiline was added in a progressively increasing dosage up to a maximum of 10 mg/day during 4 months, with the aim of a) further improving the long-term results and b) reducing the doses of the new formula of L-DOPA. A significant decrease of early morning parkinsonism and reduction of motor disability throughout the day were observed; "wearing-off" cases showed better results compared with those presenting "on-off" oscillations. A mean reduction of 20% in the doses of levodopa was achieved. Likewise, a mild reduction of dyskinesias and a mild-moderate enhancement of dystonias were recorded. Only one patient did not tolerate selegiline and two others received lower doses due to side-effects. Selegiline was capable of enhancing the antiparkinsonian effect of the new formula of L-DOPA, while allowing a reduction of the doses administered. It must also be emphasized that such improvement was achieved in complicated patients, most of whom showed some deterioration of response in the late stages of long-term sustained-release levodopa treatment.

Adult↗
PubMed1988

A combined regimen of subcutaneous lisuride and oral Madopar HBS in Parkinson's disease.

At the first stage of a pilot study involving 14 parkinsonians with motor fluctuations, treatment with standard Madopar was substituted by a sustained-release form, Madopar HBS, which attenuated fluctuations in patients with end-of-dose impairment, but achieved only moderate improvement in patients with on-off phenomena. In a second phase of the trial, 4 parkinsonians exhibiting the most severe fluctuations of mobility and the poorest response to Madopar HBS (Hydrodynamically Balanced System) were selected for treatment with a combined regimen utilizing subcutaneous lisuride infusions as the additional component. The sequence of the trial was as follows: 1. standard Madopar, 2. Madopar HBS, 3. standard Madopar combined with lisuride infusions and 4. Madopar HBS combined with lisuride infusions. Steady improvement was observed along the lines of this schedule, but the best results were obtained when Madopar HBS was combined with lisuride infusions. Subsequently motor fluctuations were less marked or disappeared, early-morning Parkinson symptoms decreased and dystonia was not recorded any longer. Even better results could be accomplished in an extended trial attempting to establish the best dosage ratio of the combination, possibly admitting increased dosage. The tolerance of the combined regimen was excellent, except in one patient who transiently exhibited delusions and postural hypotension. The combination of sustained-release Madopar and continuous infusions of the dopaminergic agonist lisuride seems to prove a more physiological and effective regimen for the treatment of severe motor fluctuations.

Administration, Oral↗
PubMed1988

Characterization of an unclassified microaerophilic bacterium associated with gastroenteritis.

Four isolates of an unclassified microaerophilic bacterium resembling Campylobacter species were characterized by growth requirements, microscopic examination, biochemical characteristics, antimicrobial susceptibility tests, and protein profile analysis. The unclassified isolates were differentiated from Campylobacter jejuni, Campylobacter coli, Campylobacter fetus subsp. fetus, Campylobacter laridis, Campylobacter pylori, and an ovine isolate. The bacterium was fusiform shaped with a corrugated surface due to the presence of periplasmic fibers and had multiple bipolar flagella. Biochemically, the bacterium was separated from the Campylobacter controls by its negative catalase reaction, negative nitrate reduction, and no growth in 1% glycine. It was also resistant to ampicillin. Protein profile analysis demonstrated nine major protein bands present in the unclassified isolates that were absent in the Campylobacter controls. The bacterium also differed from the ovine isolate by its negative catalase reaction, rapid urea hydrolysis, and susceptibility to clindamycin, erythromycin, and tetracycline. Our results showed that the unclassified bacterium was distinct from the recognized Campylobacter species.

Animals↗
PubMed1988

Case report of an unclassified microaerophilic bacterium associated with gastroenteritis.

An unusual microaerophilic gram-negative bacterium was isolated from the stools of two individuals presenting with chronic diarrhea. This bacterium resembled Campylobacter species by colonial morphology and biochemical reactions. However, microscopic examination revealed a fusiform rod with a corrugated surface, rather than a spiral rod. This is the first reported isolation of this bacterium from humans.

Adult↗
PubMed1988

Rapid method for the differentiation of gram-positive and gram-negative bacteria on membrane filters.

Microfiltration has become a popular procedure for the concentration and enumeration of bacteria. We developed a rapid and sensitive method for the differentiation of gram-positive and gram-negative bacteria, utilizing a polycarbonate membrane filter, crystal violet, iodine, 95% ethanol, and 6% carbol fuchsin, that can be completed in 60 to 90 s. Gram reactions of 49 species belonging to 30 genera of bacteria were correctly determined by the filter-Gram stain. The sensitivities of the filter-Gram stain and conventional slide-Gram stain were compared by testing dilutions of Escherichia coli, Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae suspensions in the presence and absence of whole human blood. The filter-Gram stain was approximately 100-fold more sensitive than the slide-Gram stain. The filter-Gram stain detected 2 to 100 bacteria, whereas the slide-Gram stain failed to detect less than 1,000 bacteria. The sensitivities of the methods were not significantly altered by the addition of whole human blood to the dilutions of bacteria tested. The filter-Gram stain could be a useful tool for the examination of body fluids with very low numbers of bacteria.

Blood↗
PubMed1987

Substitution of standard Madopar by Madopar HBS in parkinsonians with fluctuations.

Fourteen parkinsonian patients, 10 of them showing severe and long-standing 'on-off' effects and 4 'end-of-dose impairment', received Madopar HBS instead of standard Madopar. At the end of the dosage adaptation phase (9 weeks) most patients improved; in patients with 'on-off' phenomenon, parkinsonism became less severe, on periods were longer, and fluctuations decrease; end-of-dose impairment resolved in 4 patients. However, a longer delay in the onset of the therapeutic effect was observed after the first daily drug intake in those patients still showing severe early-morning parkinsonism. With Madopar HBS, L-dopa dosage was increased by 116%. In spite of a greater dopaminergic effect, dyskinesias were reduced, and dystonias became less marked or even disappeared.

Aged↗
PubMed1986

Parkinsonism, tardive dyskinesia, akathisia, and depression induced by flunarizine.

12 subjects, 8 women and 4 men, presented with extrapyramidal motor signs and psychic depression after treatment with flunarizine for between 3 weeks and 15 months. One woman presented with severe symptoms and 20 months after stopping flunarizine she still had dyskinesia and akathisia. The other patients showed partial or complete improvement after withdrawal of the drug.

Aged↗
PubMed1984

Visual evoked potentials and brain stem auditory potentials in Friedreich's ataxia--a longitudinal study.

Six patients with Friedreich's ataxia, 4 males and 2 females, their ages ranging from 13 to 33 years, were studied. The early manifestations started between age 7 and 13 with an evolution time between 6 and 20 years. Serial visual and brain stem auditory evoked potential recordings were made. A progressive increase in latency, reduction in amplitude and in latency inter-ocular difference of P100 were observed. The pattern of the reversal checker-board visual evoked potential was preserved. A disorganized BAEP pattern, a well defined potential I, a very small potential V and a delay in the interpeak latency were constant findings. The assumption is made of a progressive involvement of both visual and central auditory pathways. Pathophysiological mechanisms are discussed.

Adolescent↗
PubMed1982

[Clinical trial of tiapride in patients with dyskinesia (author's transl)].

Twenty-five patients with various forms of dyskinesia were given tiapride for three months. Maximal dosage was 900 mg per day. A double-blind trial of tiapride versus placebo showed significantly better results in the group given tiapride. The forms of dyskinesia which responded best to tiapride were the following: iatrogenic dyskinesia, tics (Gilles de la Tourette syndrome), and chronic chorea (Huntington disease). Patients with complex dyskinesia resulting from neonatal encephalopathy or vascular disease were not improved. The protocol used in l-dopa-induced dyskinesia is described. Changes in dyskinesia and "on-off" effect following variations in tiapride and l-dopa dosage are detailed. An unequivocal, although minor, tiapride-induced parkinson syndrome was recorded in a few patients. No instances of tiapride-induced dyskinesia or akathisia were seen. The other side-effects were either psychic (depression, drowsiness, agitation) or endocrinologic (menstrual disorders, overeating, galactorrhea).

Adolescent↗