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Biomedical subjects

C Barros

Publications and source records attributed to C Barros.

At least 73 records · Page 4Linked to original sources
PubMed1987

Visceral leishmaniasis in immunocompromised hosts.

Visceral leishmaniasis is infrequently reported in immunocompromised hosts; hence, the clinical manifestations and outcome of the disease in these patients are unknown. In a series of 10 patients with visceral leishmaniasis complicating renal transplantation (three), hematologic neoplasms (two), systemic lupus erythematosus (two), or infection with human immunodeficiency virus (three), typical hallmarks of kalaazar such as enlargement of spleen or hyperglobulinemia were absent in three and six patients, respectively. Extensive visceral involvement was noted by biopsies or autopsies in four patients. Diagnosis was made during evaluation for fever of unknown origin. Myriads of amastigotes were seen in bone marrow smears. Measurement of antibodies against Leishmania donovani was positive in each patient tested. Ultimately, three patients died, and chronic infections refractory to treatment developed in two other patients. Visceral leishmaniasis is a potentially fatal infection in immunocompromised hosts. Current antiparasitic therapy frequently fails to eradicate L. donovani from infected tissues.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Infective aortitis due to Brucella melitensis.

Infective aneurysms caused by Brucella sp. are extremely rare. B. suis and B. abortus have been implicated in a few cases but to our knowledge, B. melitensis has not been reported as a cause of mycotic aneurysm of the abdominal aorta. We here report the first case of this described in the English literature. The patient was successfully treated with resection of the infected aneurysm, placement of an axillo-bifemoral graft, and prolonged antibiotic treatment (doxycycline and streptomycin). Extended antimicrobial therapy and extra-anatomical bypass grafting procedures are advisable in the management of brucella infections of the abdominal aorta.

Aged↗
PubMed1986

Sperm migration through human cervical mucus in women with copper IUD's.

Human cervical mucus from women using Lippes Loop and T-Cu-200 IUDs was used to study sperm migration in vitro using flat capillary tubes. Cervical mucus from women bearing no IUD was used as the control. 100% of the control samples, 83% of the Lippes Loop users, and 88% of the T-Cu-200 users had more than 100 spermatozoa/field of 100x. In 17% and in 11% there were between 40 and 100 spermatozoa/field of 100x in the Lippes Loop and T-Cu-200 users. The presence of copper IUDs does not interfere with sperm migration in vitro through human cervical mucus.

Biology↗
PubMed1984

Selection of morphologically abnormal sperm by human cervical mucus.

The important role of cervical mucus from a reproduction standpoint is the transport and selection of spermatozoa. The study of the fertilizing ability of human spermatozoa by the use of zona-free hamster oocytes has shown that morphologically abnormal sperm can fuse with the zona-free hamster oocyte. The high proportion of morphologically abnormal spermatozoa present in human semen is significantly reduced after sperm migration through cervical mucus. The mucus, while a favorable environment for sperm survival, does not seem to contribute to the occurrence of sperm capacitation and acrosome reaction.

Animals↗
PubMed1982

Preservation of hamster oocytes to assay the fertilizing capacity of human spermatozoa.

Between 70 and 80% of zona-intact hamster ova survived freezing after slow cooling (approximately 0.3 degrees C/min) to -80 degrees C in Medium PB1 containing 1.5 or 2.0 M-DMSO before transfer to -196 degrees C. After slow warming (approximately 8 degrees C/min), there was no difference in survival if the DMSO was diluted out by a slow stepwise or a rapid single addition of medium. When slow cooling was terminated at -40 degrees C by direct transfer to -196 degrees C, up to 75% of the ova survived rapid warming (approximately 500 degrees C/min) and rapid dilution if the medium contained 2.0 M-DMSO. The survival rates were calculated on the basis of the number of thawed ova which retained their normal morphological appearance after a 1 h incubation before removal of the zona pellucida with trypsin. All of these ova were penetrated after incubation with mouse spermatozoa, indicating that the freezing procedure per se does not adversely affect the penetration of frozen-thawed hamster ova by heterologous spermatozoa. There was no difference in the penetration rate of human spermatozoa into frozen (34%) or fresh (42%) oocytes when a Hepes-buffered Tyrode solution containing 30 mg BSA/ml and 2.0 M-DMSO was used as the freezing medium. However, fewer ova frozen in Medium PB1 containing 4 mg BSA/ml and 2.0 M-DMSO were penetrated by human spermatozoa (18%) compared with freshly collected ova (38%). Zona-free ova did not survive the freezing procedure as well as zona-intact ova. The survival of hamster oocytes stored at -196 degrees C offers a convenient means of supplying and transporting these ova for the assessment of the fertilizing capacity of human and other heterologous spermatozoa.

Animals↗
PubMed1980

The collagen of permanently damaged nerves in human leprosy.

The collagen of nerve biopsies from ten leprosy patients was studied by the Picrosirius-polarization method and electron microscopy. It was observed that leprosy promotes a marked increase in nerve collagen content. Despite the changes induced by this disease, the localization of collagen types I and III in the endo-, peri-, and epineurium remains the same as in normal nerves.

Biopsy↗
PubMed1978

Ultrastructure of Octodon degus spermatozoon with special reference to the acrosome.

The ultrastructure of spermatozoa from the cauda epididymidis and vas deferens of Octodon degus-a Chilean hystricomorph rodent-is presented. The head of spermatozoa measured 7.7 micrometer long by 5.9 micrometer wide and the tail was 41 micrometer long. The head was flattened dorso-ventrally and ovate in outline. The acrosome was the most distinctive feature of O. degus spermatozoa. In a frontal view of the head, the rim of the acrosome surrounding the nucleus had the shape of an inverted U. The acrosomal region covering the plane of the flattened head exhibited dome-shaped protrusions. Transverse or sagittal sections of acrosomal protrusions showed that the plasma membrane and outer acrosomal membrane were evaginated, while the inner acrosomal membrane followed the contour of the nucleus. The protrusions were not distributed at random and they were absent in the equatorial segment and in the rim of the acrosome. In frontal views, near the boundary between the acrosome and post-acrosomal region, fine rods about 170 nm long ran obliquely on the caudal part of the equatorial segment. Behind the same boundary, the post-acrosomal region showed a serrated border. Phosphotungstic acid treatment at pH 0.3 produced staining at the surface of the sperm as well as within a superficial layer of the marginal thickening of the acrosome and on the acrosomal protuberances.

Acrosome↗