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Biomedical subjects

M Carulla

Publications and source records attributed to M Carulla.

13 recordsLinked to original sources
PubMed2004

Mechanisms of reduced susceptibility to amoxycillin-clavulanic acid in Escherichia coli strains from the health region of Tortosa (Catalonia, Spain).

This study investigated the mechanisms involved in reduced susceptibility to amoxycillin-clavulanic acid and the prevalence of enzymes compatible with inhibitor-resistant TEM (IRT) beta-lactamases produced by Escherichia coli isolates from patients in north-eastern Spain. The resistance mechanisms of 158 strains showing resistance or intermediate resistance to amoxycillin-clavulanic acid among 1122 ampicillin-resistant clinical isolates of E. coli were assessed on the basis of their beta-lactam resistance phenotypes. beta-Lactamases produced by strains showing resistant phenotypes suggestive of inhibitor-resistant penicillinase production were characterised by their isoelectric point. Specific activity and the concentration of clavulanic acid required to inhibit beta-lactamase activity by 50% (IC50) were determined in strains harbouring enzymes that focused at pI 5.2 or 5.4 in order to achieve presumptive identification of IRT beta-lactamases. Resistance phenotypes were consistent with overproduction of TEM-1, TEM-2 or SHV-1 beta-lactamases in 56 strains, with AmpC cephalosporinase hyperproduction in 46 strains, and with production of inhibitor-resistant penicillinases in 49 strains. Of the latter isolates, 17 produced moderately high or high levels of enzymes co-focusing with TEM-1, 17 produced enzymes co-focusing with OXA-1 (n = 12) or with PSE-1 (n = 5), either alone or in association with TEM-1, while only 15 produced enzymes with a phenotype characteristic of IRT beta-lactamases. It was concluded that resistance to amoxycillin-clavulanic acid in E. coli isolates from this area was mainly associated with presumptive overproduction of TEM-1, TEM-2 or SHV-1 beta-lactamases (46%) or of AmpC cephalosporinase (29%), while the occurrence of enzymes categorised as IRT beta-lactamases was unusual (9.5%).

Amoxicillin-Potassium Clavulanate Combination↗
PubMed1999

Period length of the light-dark cycle influences the growth rate and food intake in mice.

The adaptation of the endogenous rhythm of an organism to external cycles may be critical for the development of physiological processes in which energy is expended. We sought to determine whether growth rate depends on the degree of tuning between the external cycle and the manifestation of the circadian rhythms. To do so, we studied the growth rate and the food intake of mice (seven groups of 20 animals each) kept under symmetric LD cycles with different periods (T) of 21, 22, 23, 24, 25, 26, and 27 h, respectively, for 80 days. The mice were then kept in constant darkness for a further 80 days. Throughout the experiment, motor activity was recorded every 15 min for each mouse by means of an actimeter that used crossed infrared beams. Several variables related to the circadian motor activity rhythm were calculated, and correlated with body weight, food intake, and the efficiency of food for growth (food efficiency) calculated as: 100 x body weight increase/ amount of food intake. Results show that these three variables seem to be influenced by the number of circadian cycles that the animal has experienced, but also, and more significantly, by the degree to which the alpha phase of the individual rhythm and the dark phase of the external cycle coincide. Therefore, circadian rhythms would seem to affect the physiological processes that regulate growth and energy expenditure.

Animals↗
PubMed1995

Transforming growth factor-alpha immunoreactivity in the developing and adult brain.

Transforming growth factor-alpha immunoreactivity is examined in the developing and adult brain of cats and rats, and in the adult human brain in cryostat sections immediately processed free-floating with a well-characterized monoclonal antibody which does not cross-react with epidermal growth factor. Transforming growth factor-alpha immunoreactivity is observed in neurons of the cerebral neocortex, subiculum, hippocampus, striatum, thalamus, amygdala, basal forebrain, mesencephalon, cerebellar cortex, dentate nucleus and brainstem during development and in adulthood. The intensity of the immunoreaction directly correlates with the size of the cytoplasm. Diffuse transforming growth factor-alpha immunoreactivity also occurs in the white matter of the cerebrum, cerebellum and brainstem in the kitten, but not in the adult cat. In addition to neurons, numbers of glial cells in the cerebellar white matter, brainstem and cerebral hemispheres during development, and a few glial cells in the cerebellar cortex, diencephalon, cerebral cortex and white matter in adults are strongly transforming growth factor-alpha immunoreactive. These results support the concept that transforming growth factor-alpha is widely distributed in the brain of mammals, localizes in both neurons and glial cells, and is development dependent. These findings also suggest that transforming growth factor-alpha may play a role in the developing and adult central nervous system.

Adult↗
PubMed1989

Sensorineural high-frequency hearing loss after drill-generated acoustic trauma in tympanoplasty.

Tympanoplasty can cause a sensorineural hearing loss by a mechanism of acoustic trauma. Although this lesion appears to be relatively infrequent in clinical practice, we believe that its low apparent incidence is caused when clinicians fail to assess the auditory frequencies above 8000 Hz. Twenty-four patients with normal bone-conduction audiometric thresholds scheduled for tympanoplasty were assessed with an electro-stimulation, bone-conduction high-frequency audiometer which can measure hearing frequencies up to 20 kHz before and after surgery. A measurable hearing loss was found in the upper limits of the audible frequencies in 9 patients (37.5%), and was considered important in 4 of them (16.7%). This hearing loss was recorded above the upper frequency limit of conventional audiometers. The findings in this study indicate that drilling of the temporal bone can impair the hearing level in the high frequencies in a significant number of patients. High-frequency audiometry is a very sensitive tool to assess any damage caused to the inner ear by surgical procedures carried out in the middle ear and temporal bone.

Adolescent↗
PubMed1989

[The intensity of tinnitus].

The AA. intend to find a significant relationship between the subjective intensity of the tinnitus experienced by 47 patients, as assessed by themselves from a 7-point scale, and the objective intensity evaluated by audiometric matching of the noise. The relationship among the subjective intensity, the frequency of tinnitus and the hearing loss at the same frequency of the tinnitus aurium has also been studied. A statistically significative relationship between these parameters could not be possible find out. So they think necessary to find some others means to assess the intensity of the tinnitus.

Adult↗
PubMed1988

Necrotizing external otitis treated with ciprofloxacin. A case report.

Necrotizing (malignant) external otitis is a severe infection caused by Pseudomonas aeruginosa which occurs mainly in elderly diabetics or in immuno-depressed patients (Chandler, 1968). The management of this condition requires the association between an aminoglycoside antibiotic and an antipseudomonal beta-lactamic, given parenterally during a 4 to 6 week period. Sometimes it is necessary to continue the therapy for months until there is no evidence of residual disease (Strauss et al., 1982). Ciprofloxacin is a quinolone with antipseudomonal activity which can be taken orally, and it is a useful alternative to the current treatment. The authors report a case of necrotizing external otitis which was successfully treated with ciprofloxacin.

Aged↗
PubMed1988

Sudden hearing loss in an adolescent following a single dose of cisplatin.

Progressive hearing loss after cisplatin therapy is relatively frequent, specially in older patients, but it is less common in children and in acute form. The case of a 17-year-old patient with an intracranial tumor who suffered sudden deafness after a single course of cisplatin is presented. This patient had a previously documented very good hearing up to 20 kHz. Although it has been suggested that children with irradiated brain tumors may have an increased susceptibility to cisplatin-induced hearing loss, in this case the patient had not been subjected to radiotherapy.

Adolescent↗
PubMed1988

High-frequency audiometric changes after stapedectomy.

It is possible that, when the labyrinth is opened in stapedectomy, some form of alteration may occur within it, even if it is not detected postoperatively by routine audiometry. Injuries against the inner ear usually impair the hearing at the highest frequencies. We can assess bone-conduction hearing up to 20 kHz by means of a high-frequency audiometer. Twenty-five patients were examined with conventional and high-frequency audiometry (HFA) before and after successful stapedectomy. Conventional audiometry showed a good postoperative improvement in the low and middle frequencies. HFA showed a lowering of the auditory thresholds above 8 kHz in 20 patients (83.4%), which was not evident with conventional audiometry because it occurred above its upper frequency limit. HFA is a very valuable means of assessing the results of ear surgery, and can be used to compare different surgical techniques.

Adult↗
PubMedDate not supplied

Entrainment of the rat motor activity rhythm: effects of the light-dark cycle and physical exercise.

The circadian system is believed to be composed of a population of oscillators that couple together and generate a single rhythm. If this coupling is not strong enough, the circadian system can be dissociated into two or more groups of oscillators, and this is manifested in a dissociation of the overt rhythm into at least two circadian components. This study aims to examine the influence of factors, such as the difference in impact between T and tau, light intensity, and access to a running wheel, on the distribution of motor activity throughout the light-dark (LD) cycle and the dissociation of the rhythm. Rats were submitted to LD cycles of 23 h (T23) or 25 h. For each such cycle, half the rats were submitted to high light intensity and the other half to low light intensity. For each of these conditions, half the rats were kept in small cages, and the other half were in cages with a running wheel. Rats were maintained first under LD cycles and afterwards under constant darkness (DD). Motor activity was recorded throughout the whole experiment by means of activity meters with infrared beams. Results show that the distribution of motor activity throughout the cycle and the after effects observed in the rhythm under DD depended on light intensity and access to the wheel. Moreover, under T23, some rats showed two simultaneous circadian components whose manifestation also depended on the experimental conditions. The results indicate that the strength of circadian entrainment to LD cycles in the rat depends on three factors: the period length of the LD cycle, light intensity used during the light phase, and access to a running wheel.

Animals↗
PubMedDate not supplied

[Tinnitus in the diagnosis and prognosis of ototoxicity].

The prognostic value of tinnitus about the occurrence of hypoacusia in a patient undergoing an ototoxic treatment is not know. Ninety-five patients treated with cisplatinum, a cocleotoxic drug, have been studied to evaluate the percentage of patients with tinnitus, to assess the characteristics of these tinnitus and to know if there is a relationship between its occurrence and the degree of hearing loss that appears after treatment. Thirty-six patients (37.9%) had tinnitus, and there was not a statistically significant relationship between this symptom and the hearing loss. Therefore, tinnitus cannot be used as a prognostic factor for hypoacusia in patients undergoing treatment with cisplatinum.

Cisplatin↗