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Biomedical subjects

A Mateos

Publications and source records attributed to A Mateos.

At least 37 records · Page 2Linked to original sources
PubMed1996

Use of polymerase chain reaction in the diagnosis of tuberculosis in cats and dogs.

Samples from four dogs and four cats suspected of having tuberculosis were processed for histopathology, bacterial culture and polymerase chain reaction (PCR). A simple, rapid method for the extraction of DNA from tissue samples was used in two PCR assays designed to confirm the diagnosis of tuberculosis. The PCR assays detected all the culture-positive samples from these animals and no false positive results were obtained. The PCR technique was successful for the direct detection of organisms from the Mycobacterium tuberculosis complex and reduced the time needed for a diagnosis to two days.

Animals↗
PubMed1996

Spacer oligonucleotide typing of Mycobacterium bovis strains from cattle and other animals: a tool for studying epidemiology of tuberculosis.

The spacer oligonucleotide typing (spoligotyping) method was evaluated for its ability to differentiate Mycobacterium bovis strains. This method detects the presence or absence of spacers of the direct repeat locus of the M. bovis genome. The spacers in the direct repeat locus are amplified by PCR and are detected by hybridization of the biotin-labelled PCR product with a membrane containing oligonucleotides derived from spacer sequences that have previously been bound to a membrane. One hundred eighty-two M. bovis isolates from domestic animals (cattle, goat, sheep, and cats) and wild animals (deer and wild boar) were spoligotyped, and the results were compared with those obtained by IS6110 restriction fragment length polymorphism analysis. Two rather homogeneous clusters of isolates containing 20 and 4 types, respectively, were identified by spoligotyping. The first cluster included isolates from cattle, cats, and feral animals. By spoligotyping, isolates from the Spanish wild boar and deer had the same pattern as some bovine isolates, suggesting transmission between these animals and cattle and highlighting the importance of the study of these reservoirs. The second cluster included all the caprine and ovine isolates. Within each cluster, the patterns of the different strains differed only slightly, suggesting that the spoligotypes may be characteristic of strains from particular animal species. Spoligotyping proved to be useful for studying the epidemiology of bovine M. bovis isolates, especially of those isolates containing only a single copy of IS6110. In view of our results, we suggest fingerprinting all M. bovis strains by the spoligotyping method initially and then by IS6110 restriction fragment length polymorphism typing of the strains belonging to the most common spoligotypes.

Animals↗
PubMed1995

Effect of ethanol consumption on adult rat liver mitochondrial populations analyzed by flow cytometry.

In the present study, the effects of administering ethanol to adult male rats on the distribution of the low fluorescence population (LFP) and high fluorescence population (HFP), and the rhodamine-123 fluorescence intensity of these groups of mitochondria are analyzed by flow cytometry. Our results show that ethanol administration to adult male rats induces a redistribution of the HFP and LFP mitochondrial populations leading to an increase of the less functional HFP mitochondria. In addition, ethanol induced an increase in the mean intensity of green fluorescence of the HFP that is probably related to an increased number of rhodamine-123 binding sites per mitochondria resulting from mitochondria enlargement.

Alcoholism↗
PubMed1995

Simple and rapid detection of Mycobacterium tuberculosis complex organisms in bovine tissue samples by PCR.

Mycobacterium bovis is a slowly growing microorganism, and confirmation of the diagnosis by conventional culture is a lengthy process. A simple, rapid method for the extraction of DNA from bovine tissue samples was developed and used in a PCR designed for the diagnosis of tuberculosis. Tissues from 81 cattle from tuberculosis-infected herds (group 1) and 19 cattle from tuberculosis-free herds (group 2) were tested in this PCR, and the results were compared with those of conventional culture. The PCR assay detected 71.4% of the culture-positive animals from group 1. Tissue from all animals in group 2 were negative in the PCR assay and by culture. The described method could be used as a rapid screening technique which would be complementary to culture of tissue specimens for the routine diagnosis of bovine tuberculosis. The PCR technique is much faster than culture and reduces the time for diagnosis from several months to 2 days. It also provides for the detection of M. bovis when rapidly growing Mycobacterium spp. are present in the sample and may be able to detect the presence of M. bovis in samples even when organisms have become nonviable.

Animals↗
PubMed1991

Different media and methodologies for the detection of aflatoxin production by Aspergillus flavus strains isolated from trout feed.

We have studied the aflatoxin producing capacity of 41 Aspergillus flavus strains isolated from the mycoflora present of natural media (wheat, rice and mixed feed) synthetic medium (Aflatoxin Producing Ability Medium) and semisynthetic media (Coconut Agar Medium and Glucose Yeast Extract Agar) were compared. Aflatoxins were analysed on days 4 and 8 post-inoculation under an incubation temperature of 28 degrees C. A total of 30 strains (75.7%) were producers on natural media as detected by Thin Layer Chromatography: 23 strains on wheat, 27 on rice and 12 on mixed feed. The results by qualitative fluorescence tests on synthetic and semisynthetic media were: 3 strains positive on Coconut Agar Medium (CAM) 1 on Glucose Yeast Extract Agar (GY + Agar) and none on Aflatoxin Producing Ability Medium (APA).

Aflatoxins↗
PubMed1991

Colovesical fistula secondary to vesical gangrene in a diabetic patient.

We present a case of colovesical fistula secondary to vesical gangrene. Precipitating factors were diabetes and vesical distension caused by the obstruction of an indwelling catheter. This complication is an exceptional outcome in gangrenous cystitis and it requires emergency surgical treatment.

Aged↗
PubMed1989

Time-dependent effects of alcohol on the hypothalamic-hypophyseal-testicular function in the rat.

Adult male rats were followed throughout ethanol administration, in order to examine the time-dependent effects of ethanol on the hypothalamic-pituitary-gonadal axis. The results indicate that there is an increase in plasma prolactin levels together with a reduction in basal plasma luteinizing hormone (LH) levels, which are evident from the beginning of the intoxication period. An exaggerated response of LH to luteinizing hormone-releasing hormone was also evident from 2nd week on, in ethanol-treated rats. Basal and human chorionic gonadotropin-stimulated plasma testosterone levels were decreased in alcohol-treated as compared to control rats, at all time points studied. In addition, plasma estradiol levels were increased in ethanol-fed rats. These data suggest a direct suppressive effect of ethanol on LH release in the beginning of the intoxication period. Subsequent elevations of plasma estradiol and prolactin levels may have contributed to the maintenance of hypogonadism at the end of the intoxication period.

Animals↗
PubMed1989

[Infected cyst of the seminal vesicle associated with malformation of the upper urinary tract and contralateral vesiculitis. Embryonal and clinical aspects].

Congenital cyst of the seminal vesicle is a rare anomaly related with developmental anomaly of the mesonephric duct that is frequently associated with unilateral malformation of the upper urinary tract. New imaging techniques (ultrasound, CT, MRI) have allowed us to rediscover and study seminal vesicle disorders and its adjacent area. These techniques have afforded a better definition of cyst characteristics, its contents and anatomic relations, thus permitting more effective surgical treatment.

Adult↗
PubMed1989

[Transitional infiltrating carcinoma of the bladder. Local recurrence and metastases. Analysis of 175 cases treated with radical cystectomy].

Although much has been written on transitional cell carcinoma of the bladder, little has been reported on its metastasis. We reviewed the records of 175 patients, 4 of whom died postoperatively. All patients had been followed until their death and the surviving patients recently evaluated. Sixteen patients were lost after a long follow-up. Most of the metastases were diagnosed within 18 months after the cystectomy. Sixty-one percent of the patients presented bony metastases. The risk of metastasis is greater for sessile tumors, and increases with the degree of vesical wall infiltration, anaplasia and lymph node involvement. Evidence of lymph node involvement is not necessary for metastasis to exist. There were significantly fewer patients who died with metastasis in the patient group that did not receive preoperative radiotherapy in comparison with the other two patient groups. Of the 11 patients who revealed no evidence of tumor in the surgical specimen, 2 metastasized, indicating that metastasis was present prior to cystectomy. Treatment with cytostatic agents is the only effective therapy against distant metastasis. In our view, all patients with a tumor invading perivesical fat or who present lymph node involvement, regardless of tumor stage, should receive chemotherapy after cystectomy as early as patient condition permits.

Carcinoma, Transitional Cell↗
PubMed1988

Possible role of prolactin in the induction of hypogonadism by chronic alcohol treatment in the male rat.

Treatment of adult male rats with ethanol for a period of six weeks resulted in a numerical but not significant increase in plasma prolactin levels together with a reduction in plasma luteinizing hormone (LH) levels. Although basal plasma testosterone (T) levels were not affected in ethanol-treated animals, testicular weight was reduced and seminiferous tubules exhibited signs of atrophy. The responses of LH to luteinizing hormone releasing hormone (LHRH) and T to hCG were significantly impaired in ethanol-treated rats (p less than 0.01). Treatment with bromocriptine (1 mg/kg body weight/day), resulted in the expected decrease in plasma levels of prolactin and an increase in basal plasma LH levels to the levels found in control groups. Basal plasma T levels were not affected by bromocriptine. However, both plasma LH responses to LHRH and plasma T responses to hCG were significantly improved by bromocriptine treatment in alcoholic rats and became similar to the responses measured in control animals. The results suggest that bromocriptine-induced suppression of prolactin release has a beneficial effect on ethanol-induced hypogonadism.

Alcoholism↗
PubMed1987

[Effect of chronic consumption of alcohol on the hypothalamo-pituitary-testicular axis in the rat].

An experimental model of chronic alcohol abuse is developed, in order to study the hypothalamic-pituitary testicular axis in the rat. For this purpose basal plasma prolactin, gonadotropins, testosterone and estradiol have been measured. Also these hormones were studied after LHRH or hCG stimulation. This experimental model allows us to study the role of alcohol in hypogonadism induction. Chronic alcohol administration resulted in an inconstant decrease in plasma testosterone levels and very diminished response of it to hCG. Along with these modifications, there was an increase in basal plasma estrogen levels, as has been shown in the human. The decrease in plasma LH levels in alcoholic rats together with a normal response to LHRH suggest a toxic role of alcohol at higher levels than the pituitary. The existence of a hyperprolactinemic state under chronic alcohol ingestion is confirmed. The decrease in plasma prolactin levels after LHRH administration suggests that prolactin and gonadotropin secretion are very closely related.

Alcohol Drinking↗
PubMed1981

Dynamic properties of cockroach cercal "threadlike" hair sensilla.

Input--output (I--O) relationships were studied in cercal "thread-hair" sensilla (THS) on Periplaneta americana L. by recording from individual axons of THS while displacing the corresponding hair with a galvanometric device. Sinusoidal analysis was attempted and pulse- and ramplike displacements were then tested. The effects of stimulus orientation were also investigated. THS were spontaneously active and purely phasic and did not respond to sustained displacements. With small sinusoidal displacements (less than 30 degrees) they behaved as a linear, second-order lead system sensitive to velocity. With larger amplitudes, however, they exhibited prominent nonlinear features with minimal consequences of displacements at the extremes. Responses to other waveforms indicated second-order response components. THS were directionally sensitive. Phasic behavior and the nonlinearities may be due to mechanical properties at the base of the hair. The spike-firing threshold may also contribute. Resting activity appears to be due to neuronal factors since it was not abolished by preventing hair movements. Transducer operations were simulated in a digital computer.

Animals↗