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Biomedical subjects

C Arenas

Publications and source records attributed to C Arenas.

At least 19 recordsLinked to original sources
PubMed2003

Treatment of pulmonary sequestration by video-assisted thoracic surgery (VATS).

Pulmonary sequestration is a rare malformation of the respiratory tract that accounts for 0.15-6.4% of all congenital lung anomalies. Treatment requires resection of the lesion, provided that there is no technical contraindication. The lesion should first be evaluated using video thoracoscopy and then resected whenever possible by video-assisted thoracic surgery (VATS). We report a case of extralobar pulmonary sequestration in a 48-year-old woman. She underwent lobectomy by VATS and achieved an excellent outcome.

Bronchopulmonary Sequestration↗
PubMed2001

[Analysis of a programme of direct referral between primary and specialist care in potential surgery patients].

OBJECTIVE: To describe the results of a programme of direct referral of potential surgery patients between primary and specialist care, designed to lessen waiting-times.Design. Prospective, longitudinal and descriptive study. SETTING: Health Area N. masculine 19 (Valencian Health Service): Surgery Service of Elche Hospital and 6 Health Centres. PARTICIPANTS: Patients with pathologies that do not need special techniques for diagnosis except examination and who have a clear irrefutable indication of surgery without risk factors (ASA I-II).Intervention. The referral protocol consists of: a) diagnosis of pathology and pre-operative study in primary care (PC); b) appointment made by phone for the surgery clinic at the hospital, where diagnosis and pre-operative study are confirmed; c) referral and operation in the unit of non-hospital major surgery (UCMA); d) monitoring post-operation by the home hospitalisation unit (HHU) or preferably by the health centre, and e) check-up at the surgery clinic. Main measurements. The degree of agreement between PC and the specialist, assessment of the pre-operative study, and waiting time. RESULTS: 86 patients were referred (average age, 35; 76% male) by 28 doctors. The most common pathologies were hernia (36%), pilonidal sinus (23.2%) and miscellaneous (32.5%). There was general agreement in diagnosis in 90.7% of cases. 89.5% of patients brought the proper pre-operative study. Mean waiting time between the primary care consultation in the different procedures and the first hospital consultation was 19 days; with 44 more days elapsing till the surgical operation. CONCLUSIONS: This new programme is effective and economic, in that there is < > of patients, waiting time is reduced by over 7 months for pilonidal sinus and by over 2 years for hernia pathology, and the procedure can be used for a large number of patients, as the pathologies involved are very common.

Adolescent↗
PubMed2001

Colonization of America by Drosophila subobscura: heterotic effect of chromosomal arrangements revealed by the persistence of lethal genes.

About 20 years ago Drosophila subobscura, a native Palearctic species, colonized both North and South America. In Palearctic populations lethal genes are not associated in general with particular chromosomal arrangements. In colonizing populations they are not randomly distributed and usually are associated to a different degree with chromosomal arrangements caused by the founder event. The persistence of two lethal genes in the colonizing populations, one completely associated with the O(5) inversion and the other partially associated with the O(3+4+7) arrangement, has been analyzed. In all populations studied (five North American and six South American) the observed frequency of the lethal gene completely associated with the O(5) inversion is higher than expected, the difference being statistically significant in all South American and one North American populations. The observed frequency of the lethal gene partially associated with the O(3+4+7) arrangement is also significantly higher than expected. Taking into account that the O(5) inversion exhibits significant latitudinal clines both in North and South America, an overdominant model favoring the heterokaryotypes seems to be in operation. From this model, a polynomial expression has been developed that allows us to estimate the relative fitness and the coefficient of selection against all karyotypes not carrying the O(5) inversion. The relative fitness of the O(5) heterokaryotypes is higher in South American than in North American populations. Furthermore, the observed frequencies of the lethal genes studied are in general very close to those of the equilibrium. This case is an outstanding demonstration in nature of an heterotic effect of chromosomal segments associated with lethal genes on a large geographic scale.

Animals↗
PubMed2001

A statistical analysis of nucleotide substitutions in the Drosophila Adh region reflects irregularities in molecular clocks.

Substitutions rates are expected to be rather constant when a gene is compared between species. To analyze this feature, Ka/Ks ratios have been studied for Alcohol dehydrogenase (Adh) and Alcohol dehydrogenase duplication (Adh-dup) genes in Drosophila species. Adh Ka/Ks values are lower in intrasubgenus comparisons involving species of the Sophophora group than when these species are compared to the D. immigrans and S. lebanonensis, and this difference does not occur in the Adh-dup comparisons.

Alcohol Dehydrogenase↗
PubMed2000

Colonization of America by Drosophila subobscura: spatial and temporal lethal-gene allelism.

About twenty years ago Drosophila subobscura, a western Palearctic species, colonized both North and South America. Lethal genes in the O chromosome has been subject to much research. Lethal gene allelisms between American populations far away have been studied. These allelisms were not negligible, but all cases were due to the lethal gene completely associated to the O5 chromosomal inversion. Here we analyze the lethal genes in a new American population of D. subobscura (Centralia, Washington), located fairly close to a previously studied population (Bellingham, Washington) and separated in space and time with other American populations (Gilroy I and II in California and Santiago de Chile). The frequencies of lethal and semilethal genes of Centralia were 16.9+/-4.6 and 6.2+/-3.0, respectively. The intrapopulational allelism of Centralia was 0.122+/-0.036. Interpopulational allelisms were studied using the lethal genes from the populations separated in space and time from Centralia. The interpopulational allelisms between Centralia and Gilroy I (California) and between Centralia and Bellingham (Washington) were higher than the intrapopulational allelism (0.155+/-0.032 and 0.153+/-0.024, respectively). In all these cases allelism was due to a complete association between a lethal gene and the O5 chromosomal inversion. Accordingly, no other lethal genes are shared in these populations.

Alleles↗
PubMed1998

[Analysis of the changes observed in the sleep EEG recording of patients with juvenile myoclonic epilepsy].

OBJECTIVE: The initial phases and transitional periods of sleep facilitate electroclinical manifestations of juvenile myoclonic epilepsy (JME). The period at the time of waking is identified in the different phases of sleep by cyclic electrophysiological oscillations, which in turn are synchronous with the spike-and-wave or multiple spike-and-wave activity of the electric crises seen in JME and other epileptic syndromes. This observation supports the theory of an alternating cyclical pattern (ACP) as the trigger of these discharges. PATIENTS AND METHODS: Following classical macrostructural and microstructural patterns of EEG sleep analysis, we investigated electrophysiological behavior in 13 patients diagnosed as having JME, and 5 persons of homogeneous epidemiological characteristics as controls. RESULTS: In our study we observed that both groups had similar macrostructural sleep parameters. However, in patients prone to crises, these were concentrated in the first two hours recorded and showed no differences in sleep-waking transition or ACP of phase I sleep. These were significant when both periods were compared with the remaining NREM sleep. CONCLUSION: We conclude from this study that ACP is the microstructural element of sleep which modulates and permits classification of epileptiform anomalies, mainly in studies at the time of wakening.

Child↗
PubMed1997

[Devic's optic neuromyelitis. Follow-up of the evolution of the medullary lesions using magnetic resonance].

The nosology of Devic's optic neuromyelitis (NMOD) is controversial. Although classically considered to be a variety of multiple sclerosis, there are a number of differentiating characteristics which would permit classification as a separate condition. The evolution of changes in the medulla, as shown by magnetic resonance, is described in a patient with recurrent episodes of myelitis and optic neuritis. In successive exacerbations widening of the medulla was seen, with the appearance of areas of cavitation which later gave rise to atrophy of the medulla. During an 18 year follow-up period the symptoms were only of visual and medullary pathology, on magnetic resonance no other lesions were found in other parts of the central nervous system. The condition corresponded to Devic's optic neuromyelitis (NMOD). Whether it is a variant type of multiple sclerosis or a distinct entity, NMOD shows differentiating characteristics.

Atrophy↗
PubMed1997

[Concurrence of short and long lasting episodes of nocturnal paroxysmal dystonia in an epileptic patient].

We report the case of a patient with nocturnal paroxysmal dystonia (NPD) meeting not only the diagnostic criteria described by Lugaresi et al. in 1981, but also presenting with features suggestive of underlying epilepsy as well as other differences from the diagnostic criteria originally described for NPD, such as short- and long-lasting episodes and poor response to antiepileptic drugs. The case we describe suggests a different entity, one that is unrelated to epilepsy or true NPD.

Adult↗
PubMed1996

[The effect of angioplasty on cerebral vasomotor reactivity in patients with important stenosis of the internal carotid artery].

INTRODUCTION: We present the preliminary results of the effects on percutaneous translumenal angioplasty (PTA) cerebral haemodynamics in thirty patients with important stenosis of the internal carotidal artery. MATERIALS AND METHODS: Using transcranial doppler (TCD) with acetazolamide (ACZ) as a vasodilatory stimulus, we assessed vasomotor reactivity (VR and pulsatility index (Pl) both before and three months after angioplasty. We also carried out single photon emission computerized tomography (SPECT) and cartography and frequency measurement by electroencephalogram (EEG) again both before and after PTA. RESULTS: Of the first twelve patients who completed the study, VR was maintained in nine and PI increased after PTA in seven. In three patients VR was exhausted and in two recovered after PTA. CONCLUSIONS: PTA improved cerebral haemodynamics. Similar more exhaustive studies are needed if revascularization techniques are to be useful in treating patients with this level of stenosis but who are asymptomatic as to the risk of haemodynamic cerebral vasomotor angioplasty.

Acetazolamide↗
PubMed1995

[Sumatriptan and cluster headache].

Double-blind studies have demonstrated the efficacy of sumatriptan for the treatment of cluster headache (CH) but little is known about its use on a daily basis. The open trial reported here analyzed the efficacy, tolerance and appropriateness of subcutaneous administration of sumatriptan; the results are compared with findings for other treatments of CH. Sumatriptan was used in 232 attacks suffered by 16 patients and its effect was very rapid. Pain began to diminish a mean 9 minutes after injection and the most intense had disappeared in less than 15 minutes. All the patients preferred sumatriptan to other treatments. No serious side effects were recorded and the patients were satisfied with subcutaneous injection. Sumatriptan was considered the first choice medication for treatment of CH symptoms, although its high cost is a drawback that had to be taken into account.

Adolescent↗
PubMed1995

[Congenital myopathy with cores and nemaline rods in one family].

We present a mother and 2 children with congenital myopathy whose clinical signs were facial paresis in all three, and mild involvement of the lower extremities in the mother and one son. All three presented skeletal abnormalities, hypertelorism, arched palate, retraction of the Achilles tendon or short neck. Symptoms were not progressive and muscle biopsies showed central cores and nemaline rods in the mother and only nemaline rods in the 2 sons. The mother also suffered carpal tunnel syndrome, as had other members of the family as the result of autosomal dominant inheritance.

Adolescent↗
PubMed1995

[Recessive distal myopathies. Five cases].

We present five patients with distal weakness in the lower extremities with onset in adolescence. Paresis tended to occur in the gastrocnemia in 3 patients and was accompanied by marked elevation of CPK (> 10 times higher than normal). Muscle biopsies showed signs of dystrophy. The clinical picture for these patients was consistent with the diagnosis of recessive distal myopathy (Miyoshi's form). The differential sign in the other 2 cases was greater involvement of the anteroexternal leg muscles and the presence of rimmed vacuoles similar to those characteristic of Nonaka's vacuolar distal myopathy.

Adolescent↗
PubMed1994

Regulation of the rab17 gene promoter in transgenic Arabidopsis wild-type, ABA-deficient and ABA-insensitive mutants.

The abscisic acid-responsive gene rab17 is induced during maize embryo maturation and in vegetative tissues under water stress conditions. To investigate how ABA is involved in the induction of the rab17 gene, we present here a genetic approach to analyse the transcriptional regulation of the 1.3 kb rab17 promoter fragment in transgenic wild-type Arabidopsis and mutants which are deficient (aba) and insensitive (abi1, abi2 and abi3) to ABA. During seed development the rab17 promoter fragment confers similar temporal and spatial regulation on the reporter gene GUS, both in transgenic wild-type and ABA-deficient and ABA-insensitive mutants. The rab17 promoter was only active in embryo and endosperm during late seed development, although the ABA-deficient embryo mutant showed a reduction in the level of GUS activity. During germination rab17 promoter activity decreases, and GUS activity is not enhanced by water stress in transgenic wild-type and mutant plants. In contrast, transcription of the Arabidopsis endogenous rab gene is stimulated by water stress, both in wild-type and ABA-insensitive mutants. Our data suggest that different molecular mechanisms mediate seed-specific expression and ABA water stress induction of the rab17 gene and indicate strong conservation of the seed-specific regulatory mechanism for rab genes in monocot and dicot plants.

Abscisic Acid↗
PubMed1994

[Alien limb behavior associated with Alzheimer's disease].

A 48-year-old female developed apraxia, followed by aphasia and dementia. Clinical examination also showed an alien member sign, supranuclear gaze paresis, myoclonus and rigidity on the right arm. The examination of the frontal lobe biopsy showed typical lesions of Alzheimer's disease as the only neuropathological abnormality. The association of this clinical syndrome with Alzheimer's pathology is unusual.

Alzheimer Disease↗
PubMed1994

[Chronic cluster headache: course and outcome of treatment].

We analyze the results of treatment and the course of disease in 20 patients suffering from chronic cluster headache. Patients were followed for an average of 5 years. Sumatriptan provided the most effective relief of symptoms in those who used that medication. The results of surgical and medical prophylaxes were poor. The disease either remitted or changed to an episodic variety after several months or years in most patients. There is no evidence to suggest that these changes were related to any particular treatment.

Adrenal Cortex Hormones↗