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Biomedical subjects

C Henríquez

Publications and source records attributed to C Henríquez.

At least 19 recordsLinked to original sources
PubMed2005

Interaction and reactivity of urocanic acid towards peroxyl radicals.

The capacity of urocanic acid to interact with peroxyl radicals has been evaluated in several systems: oxidation in the presence of a free radical source (2,2'-azobis(2-amidinopropane; AAPH), protection of phycocyanin bleaching elicited by peroxyl radicals, and Cu(II)- and AAPH-promoted LDL oxidation. The results indicate that both isomers (cis and trans) are mild peroxyl radical scavengers. For example, trans-urocanic acid is nearly 400 times less efficient than Trolox in the protection of the peroxyl radical promoted bleaching of phycocyanin. Regarding the removal of urocanic acid by peroxyl radicals, nearly 100 muM trans-urocanic acid is required to trap half of the produced radicals under the employed conditions (10 mM AAPH, 37 degrees C). Competitive experiments show that the cis-isomer traps peroxyl radicals 30% less efficiently than the trans-isomer. Given the high concentrations that trans-urocanic acid reaches in skin, its capacity to trap peroxyl radicals could contribute to the protection of the tissue towards ROS-mediated processes. Furthermore, both isomers, and particularly the cis-isomer, protect LDL from Cu(II)-induced oxidation.

Amidines↗
PubMed2003

Severely elevated intrarenal arterial impedance and abnormal venous flow pattern in a normal functioning kidney graft.

Serial Doppler sonographic impedance measurements represent the most common diagnostic method for noninvasive monitoring of kidney grafts. Severely elevated arterial impedance is almost always associated with graft dysfunction. However, we describe in the present work a renal transplant recipient with optimal graft function despite permanently elevated arterial impedance (pulsatility index (PI) ranging from 2.9-3.0, and resistive index (RI) = 1.0 as well as an abnormal venous flow pattern. In contrast, the contralateral graft from the same cadaver donors transplanted into a 17-year-old female patient displayed normal range PI and RI values in conjunction with a normal serum creatinine. Known causes of arterial impedance elevation such as rejection, cyclosporine, urinary obstruction, and external graft compression were excluded. Other extrarenal causes of high impedance, such as aortic insufficiency and reduced aortic compliance, were also excluded. No evidence of impaired venous outflow at the site of the anastomosis of the main renal vein to the iliac vein was found. Those findings support the view that impedance indexes are hemodynamic rather than functional parameters.

Adolescent↗
PubMed2000

Renal Doppler sonographic and histologic findings in post-transplant primary cytomegalovirus disease.

Cytomegalovirus (CMV) infections frequently develop in renal transplant patients. The transplanted kidney may be not only the source of infection but also the target for it. We report a case of primary CMV infection in a seronegative patient who received a graft from a seropositive cadaveric donor. The onset of CMV was clinically apparent on post-transplant day 22. Interestingly, soon after transplantation, the patient developed a long-lasting graft dysfunction episode for which diffuse endothelial-cell swelling was the most relevant finding at biopsy. On sonography, renal graft vascular impedance deteriorated and improved repeatedly during the follow-up period. We postulate that the patient had CMV-induced immunogenic-mediated endothelial-cell injury.

Adult↗
PubMed1997

Renal duplex ultrasonography in the diagnosis and follow-up of a case of accelerated transplant rejection treated with OKT3.

Several studies have discussed the value of ultrasonography in the differential diagnosis of early renal allograft dysfunction. However, much controversy still remains regarding its real usefulness in this clinical setting. Among the causes of early graft dysfunction, accelerated rejection is one of the most serious and leads frequently to early graft loss; early diagnosis and aggressive therapy are essential to prevent irreversible graft damage or even graft rupture. Limited attention has been paid to the evaluation of accelerated rejection treated with monoclonal CD3 antibodies by means of combined B-mode and Doppler ultrasonography. We report one such a case with a favorable outcome.

Graft Rejection↗
PubMed1992

The empty sella: results of treatment in 76 successive cases and high frequency of endocrine and neurological disturbances.

OBJECTIVE: We assessed the frequency of endocrine or neurological disturbances and the results of surgery in patients with empty sella, diagnosed with cisternography and/or computerized tomography scanning. DESIGN AND PATIENTS: Analysis of hospital records of 76 successive patients (73 primary, three secondary empty sella) from a single institution. MEASUREMENTS: Clinical and neuro-ophthalmological evaluation. Serum PRL, GH, TSH, LH, FSH, T4, T3 by radioimmunoassay. Diagnosis of empty sella with cisternography and/or computerized tomography scanning (n = 69), or discovered at surgery (n = 7). RESULTS: Patients with empty sella had: headache (69.7%), visual disturbances (34.2%), cerebrospinal fluid rhinorrhoea (11.8%), endocrine disturbances (51.4%, including hyperprolactinaemia, acromegaly, Cushing's syndrome). A pituitary tumour was discovered in two patients, in seven other ones it was suspected but not found at surgery. Transsphenoidal packing of empty sellas was done in 56 cases, with 7.1% post-operative complications. With surgery there was improvement of headache in 71%, of visual disturbances in 46%. Cerebrospinal fluid rhinorrhoea (discovered at surgery in four other patients) was not resolved by the first operation in six out of 13 patients. In 20 patients without surgery, headache improved in 64.6%. CONCLUSIONS: The empty sella is frequently associated with a variety of neurological and endocrine disturbances, which is contrary to conventional belief. Cerebrospinal fluid rhinorrhoea is not a rare complication and it may be difficult to treat. Some cases of empty sella may be due to partial pituitary apoplexy. Autoimmunity may have existed in other cases. Surgery may be useful in many patients, but a judicious selection is needed because it entails complications and non-operated patients may improve spontaneously.

Adolescent↗
PubMed1992

[Pregnancy in renal transplant recipients. Long-term evaluation of their children].

The course of eight pregnancies in seven renal transplant patients was analyzed. Immunosuppression consisted of Azathioprine and Prednisone. Pregnancy lasted from 32 to 39 weeks and the fetal development corresponded to the gestational age in every case. There were three cases which had complications during the pregnancy. One case had severe arterial hypertension, proteinuria and pedal edema, which was thought to be due to pre-eclampsia. Another patient had cholestatic jaundice and premature fissure of membranes and the third patient also had this last complication. Four patients had vaginal deliveries and in four cesarean section was performed. Renal function did not deteriorate during any of the pregnancies nor during the follow-up period, but the expected increase in creatinine clearance was not found. Clinical evaluation of the children, 4 months to 8 years of age, did not disclose any abnormalities.

Child↗
PubMed1991

[Anomalies of the umbilical cord and its association with fetal malformations].

An evaluation of 1500 perinatal autopsies is presented and the findings of umbilical cord anomalies are related to fetal malformations. The most frequent pathologies of the umbilical cord were one umbilical artery and stenosis of the cord. The author highlights the importance of a thorough examination of the umbilical cord and of the placenta.

Autopsy↗
PubMedDate not supplied

[Goiter and chronic lymphocytic thyroiditis].

Sixty patients with goiter, aged 3 to 16 years, 58 girls, were studied for evidence of chronic lymphocytic thyroiditis (CLT). Thirty eight patients, 63%, presented two or more diagnostic elements of TLC, according to Fisher's criteria, with a high frequency of thyroid function involvement (47.4% had hypothyroidism and 18.4% had hyperthyroidism). The rest of the patients with diffuse goiter (37%) did not meet Fisher's criteria, they were mostly euthyroid (95%) and they were designated "non thyroiditis goiter". All patients with probable CLT had positive antimicrosomal antibodies at relatively high titer (greater than 1 x 600 in 71% of the cases) and 32% of them had both antimicrosomal and antithyroglobulin antibodies. In the "non thyroiditis goiter" group we found 28% of children with positive antimicrosomal antibodies at low titers (1 x 100 and 1 x 400, respectively). In a control group of 28 children of similar ages, without endocrine diseases neither familiar history of thyroid diseases only 3 (11%) cases showed positive antimicrosomal antibodies, always at low serum titers.

Adolescent↗