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Biomedical subjects

R Trevino

Publications and source records attributed to R Trevino.

15 recordsLinked to original sources
PubMed2001

Human transferrin G277S mutation: a risk factor for iron deficiency anaemia.

Numerous polymorphisms of the transferrin gene result in a range of electrophoretic variants. We show that one of these mutations has a functional consequence. A G-->A mutation at cDNA nucleotide 829 (G277S) was associated with a reduction in total iron binding capacity (TIBC). In menstruating white women, the G277S genotype was a risk factor for iron deficiency anaemia: iron deficiency anaemia was present in 27% of homozygous G277S/G277S women, 10% of G277G/G277S heterozygous women and 5% of homozygous wild-type G277G/G277G women.

Adult↗
PubMed2000

Molecular characterization of a case of atransferrinemia.

Hereditary atransferrinemia is a rare but instructive disorder that has previously been reported in only 8 patients in 6 families. It is characterized by microcytic anemia and by iron loading, and can be treated effectively by plasma infusions. We now report the first case known in the United States. We determined the sequences flanking the exons of the human transferrin gene and sequenced all of the exons and some of the flanking regions of the patient's DNA and that of her parents. The patient's DNA revealed a 10-base pair (bp) deletion, followed by a 9-bp insertion of a duplicated sequence. There was also a G-->C transversion at complementary DNA (cDNA) nt 1429, predicting that a proline was substituted for the alanine in amino acid position 477 (Ala 477 Pro). The latter mutation occurs at an evolutionarily highly conserved site; 704 control alleles were screened and this point mutation was not found. Each of the patient's transferrin genes contains one mutation, ie, the patient is a compound heterozygote for these mutations, because one was found in each of her parents. In addition to these mutations, which we regard to be causative in the patient's atransferrinemia, a silent polymorphism at cDNA 1572 G-->C was found in exon 13 as well as 2 previously unreported polymorphisms at IVS8 + 62 c-->t and IVS14-4 c-->a. The mutation in nt 1572 and that in intron 8 were common in the general population; the intron 14 mutation is rare.

Adult↗
PubMed1999

Rectal-scalp temperature difference predicts brain death in children.

When brain death in children occurs, commonly the scalp feels cold despite a normal core temperature. This phenomenon might reflect absent cerebral blood flow and metabolic activity. The authors, therefore, measured rectal-scalp temperature differences in critically ill comatose children to test the hypothesis that a particular temperature difference may correlate with clinical brain death. In a prospective cohort study set in a pediatric intensive care unit, rectal-scalp, rectal-abdomen, and rectal-mastoid temperatures in critically ill comatose children older than 18 months of age were measured before and during brain death evaluations. Twelve children were enrolled. Clinical criteria for brain death were met by seven patients, and five patients survived. All of the seven children who died had rectal-scalp temperature differences greater than 4 degrees C (mean = 6.7, range = 6.0-7.4) at the time of clinical brain death. No survivor had a rectal-scalp temperature difference of 4 degrees C at any time (mean = 3.4, range = 2.9-3.9). Rectal-scalp temperature differences of those who died and those who survived were significantly different at the P < 0.005 level. Rectal-abdomen and rectal-mastoid temperature differences did not correlate with clinical brain death or rectal-scalp temperature difference. In this preliminary study a rectal-scalp temperature difference of greater than 4 degrees C correlates with clinical criteria for brain death in children.

Biomarkers↗
PubMed1998

Idiopathic recurrent branch retinal arterial occlusion in a young adult.

A case of bilateral, idiopathic, and recurrent branch retinal arterial occlusions occurring in an otherwise healthy 36-year-old woman is presented. The diagnosis of idiopathic recurrent branch retinal arterial occlusion was made after extensive medical investigations failed to find a cause for the occlusions. The differential diagnosis of retinal arterial occlusion in the young is discussed.

Adult↗
PubMed1995

Chiasmal syndrome.

BACKGROUND: Chiasmal syndrome is the constellation of signs and symptoms that are associated with lesions of the optic chiasm. Pituitary adenoma is its single most common cause. METHODS: A MEDLINE search of the biomedical literature was conducted to uncover papers on topics related to chiasmal syndrome published since 1989. RESULTS: The MEDLINE search retrieved a total of 163 citations. Each citation was screened for relevance. Copies of each relevant paper were obtained and their references were examined for any publications that the original search may have missed and for older publications that continue to be of importance. CONCLUSIONS: This review article discusses the etiology, diagnosis, and management of chiasmal syndrome.

Adenoma↗
PubMed1994

Nosocomial infections in the pediatric intensive care unit.

Pediatric intensive care units have contributed considerably to the management of children with severe diseases and life-threatening conditions. The use of mechanical ventilation, invasive monitoring, and indwelling catheters increase the risk for nosocomial infection. Improving infection control practices and surveillance can significantly reduce the incidence of nosocomial infections.

Bacteremia↗
PubMed1991

A radiographic study of condyle position at various depths of cut in dry skulls with axially corrected lateral tomograms.

Fifty dry skulls were evaluated by means of submental vertex radiographs and axially corrected tomograms. The condyles were classified into four groups according to anterior surface and shape as viewed on the submentovertex radiograph. Thirty condyles were classified as having a flat anterior surface, 27 as convex, 19 as concave, and 24 as triangular. The analysis of variance for the depth of cut demonstrated (1) no statistically significant difference between the condyle/fossa relationship at the various depths of cut for the convex, flat, and triangular condyles and (2) a statistically significant difference between the condyle/fossa relationship of the concave condyles. The difference was significant at the p = 0.107 level for the anterior joint space (A), and at the p = 0.0671 level for the posterior joint space (B). The analysis of variance, in regard to the subject variable, demonstrated a statistically significant difference at the p = 0.0001 level for all condyles.

Analysis of Variance↗
PubMed1986

Difference in acid-base state between venous and arterial blood during cardiopulmonary resuscitation.

We investigated the acid-base condition of arterial and mixed venous blood during cardiopulmonary resuscitation in 16 critically ill patients who had arterial and pulmonary arterial catheters in place at the time of cardiac arrest. During cardiopulmonary resuscitation, the arterial blood pH averaged 7.41, whereas the average mixed venous blood pH was 7.15 (P less than 0.001). The mean arterial partial pressure of carbon dioxide (PCO2) was 32 mm Hg, whereas the mixed venous PCO2 was 74 mm Hg (P less than 0.001). In a subgroup of 13 patients in whom blood gases were measured before, as well as during, cardiac arrest, arterial pH, PCO2, and bicarbonate were not significantly changed during arrest. However, mixed venous blood demonstrated striking decreases in pH (P less than 0.001) and increases in PCO2 (P less than 0.004). We conclude that mixed venous blood most accurately reflects the acid-base state during cardiopulmonary resuscitation, especially the rapid increase in PCO2. Arterial blood does not reflect the marked reduction in mixed venous (and therefore tissue) pH, and thus arterial blood gases may fail as appropriate guides for acid-base management in this emergency.

Acid-Base Equilibrium↗
PubMed1985

Echocardiographic observations during cardiopulmonary resuscitation: a preliminary report.

Echocardiographic studies were conducted during CPR to establish whether blood flow through the heart was passive or whether cardiac compression accounted for forward blood flow. M-mode and two-dimensional echocardiographic studies were performed on anesthetized minipigs during external CPR and open-chest cardiac massage. With external compression, mitral valve closure was observed during compression systole and valve opening during compression diastole. The aortic valve opened during compression systole and closed during compression diastole. Identical observations were made during open-chest cardiac compression. Left ventricular area was computed during compression systole. A 24% reduction in the area of the left ventricle during precordial compression confirmed left ventricular ejection of blood. Saline tracer was injected into the right and left ventricles. Echocardiographic observation of the tracer demonstrated forward blood flow across the pulmonic and aortic outflow tracts during compression. There was minimal valvular regurgitation. These findings support the concept of cardiac compression as a mechanism for forward blood flow during open- and closed-chest CPR.

Animals↗
PubMed1984

Incidence of retained placenta following induction of parturition with corticoids or prostaglandins.

Three trials involving 214 cows were conducted to 1) compare the timing of events during normal parturition with parturition induced with a corticoid or a prostaglandin; 2) determine if synchrony could be improved by injection of steroids either concurrently or after injection of a corticoid or a prostaglandin; 3) determine if the incidence of retained placenta could be reduced; and 4) explore methods of treating retained placenta. The timing of events following induction of parturition was compared with that following a normal parturition in 76 heifers. The time from onset of labor to appearance of the placenta, abdominal press, appearance of feet and expulsion of the fetus did not differ between normal and induced parturition. The time from onset of labor to calf standing was increased from 2.3 +/- 2.0 hours in normal parturition to 5.8 +/- 5.5 hours in cows receiving 10 mg of flumethazone (P<0.05). The interval from onset of labor to calf nursing also tended to be longer (P>0.05<0.01). All control cows expelled fetal membranes by 48 hours after onset of labor, but the proportion expelled by the treatment groups varied from 24 to 76%. None of the treatments used in this study significantly increased placental expulsion over that noted when flumethazone or prostaglandins were used alone. No difference in placental expulsion time was noted in cows douched with nolvasan or injected with 30 cc oxytetracycline. None of the treatments used in the three trials reported in this study improved synchrony of parturition over that noted in the cows receiving only an injection of flumethazone or prostaglandins.

Journal Article↗