Search PubMed⌕ Search

Biomedical subjects

C Hernandez

Publications and source records attributed to C Hernandez.

At least 91 records · Page 5Linked to original sources
PubMed1988

Bronchoconstriction elicited by isocapnic hyperpnea in guinea pigs.

We demonstrated spontaneous self-limited bronchoconstriction after eucapnic dry gas hyperpnea in 22 anesthetized, mechanically ventilated guinea pigs pretreated with propranolol (1 mg/kg iv). Eucapnic hyperpnea "challenges" of room temperature dry or humidified gas (5% CO2-95% O2) were performed by mechanically ventilating animals (150 breaths/min, 3-6 ml tidal volume) for 5 min. During a "recovery" period after hyperpnea, animals were returned to standard ventilation conditions (6 ml/kg, 60 breaths/min, 50% O2 in air, fully saturated at room temperature). After dry gas hyperpnea (5 ml, 150 breaths/min), respiratory system resistance (Rrs) increased in the recovery period by 7.7-fold and dynamic compliance (Cdyn) decreased by 79.7%; changes were maximal at approximately 3 min posthyperpnea and spontaneously returned to base line in 10-40 min. This response was markedly attenuated by humidification of inspired air. Four consecutive identical dry air challenges resulted in similar posthyperpnea responses in four animals. Increasing the minute ventilation during hyperpnea (by varying tidal volume from 3 to 6 ml) caused increased bronchoconstriction in a dose-dependent fashion in six animals. Neither vagotomy nor atropine altered the airway response to dry gas hyperpnea. We conclude that dry gas hyperpnea in anesthetized guinea pigs results in a bronchoconstrictor response that shares five similar features with hyperpnea-induced bronchoconstriction in human asthma: 1) time course of onset and spontaneous resolution, 2) diminution with humidification of inspired gas, 3) reproducibility on consecutive identical challenges, 4) stimulus-response relationship with minute ventilation during hyperpnea, and 5) independence of parasympathetic neurotransmission.

Airway Resistance↗
PubMed1986

Qualitative assessment of uteroplacental blood flow: early screening test for high-risk pregnancies.

A pulsed Doppler apparatus was used to assess the blood flow velocity profiles in uterine vessels (arcuate arteries) at 16 to 18 weeks' gestation to determine if complications associated with impaired trophoblastic invasion of the placental bed (ie, pregnancy-induced hypertension, intrauterine growth retardation, and fetal asphyxia) could be predicted by this measurement. Thirty-one of 126 consecutive pregnancies developed one or more of the above complications. The sensitivity was 68% and the specificity 69%; the predictive value of a positive test was 42% and that of a negative test 87%. These results seem to represent an improvement over existing predictive techniques. Early identification of such a high-risk group might allow more discerning use of antenatal resources and may lead to new therapeutic measures.

Blood Flow Velocity↗
PubMed1985

Antibodies to vimentin intermediate filaments in sera from patients with SLE and RA: quantitation by solid phase radioimmunoassay.

A solid phase radioimmunoassay was used to quantify levels of antibodies to vimentin intermediate filaments (VIF) of the cytoskeleton in sera from patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Significantly higher levels of these antibodies were found in 52% of the SLE sera studied, compared to 6% in RA sera and 10% of sera from healthy controls. These antibodies include IgG and IgM classes of immunoglobulins. Our results show that high levels of anti-VIF antibodies are more prevalent in SLE sera, whereas no significant differences are found between sera from patients with RA and healthy controls.

Adult↗
PubMed1983

Comparative electrophysiological evaluation of atrial activation and sinoatrial node function following Senning and Mustard procedures: an experimental study.

We compared several electrophysiological variables before and after Mustard and Senning procedures in 14 mongrel dogs and made the following three observations. First, after the Senning operation, the atrial activation in the areas of the anterior and middle internodal tracts is undamaged. After the Mustard procedure, however, conduction through the interatrial septum is practically abolished. Both techniques damage the area of the posterior internodal tract. On the whole, there is greater dispersion of atrial epicardial mapping with the Senning operation. Second, several degrees of depression in the sinus node automatism and intraatrial conduction were observed with both techniques. Third, atrioventricular block in various degrees was observed only after the Mustard procedure. The atrioventricular dissociation observed after the Senning operation was dependent on sinus pacemaker dysfunction only. We think that from the electrophysiological point of view, the Senning procedure is a valid alternative for repair of transposition of the great arteries.

Animals↗
PubMed1982

[Diagnosis of secondary tumors of the pancreas. Analysis of 13 cases].

The Authors report their experience of 13 cases of metastatic carcinoma of the pancreas, diagnosed over 350 pancreatic cancers examined by digestive angiography (4%). The rarity of this localization is emphasized and is affirmed that any organ may cause pancreatic metastasis (liver, bile ducts, oesofagus) although the kidney and the lung are more frequently the original sites. The pancreatic metastases were of different types but the multilocalized or the total forms don't prevail over the single ones. The angiographic modifications induced by these secondary lesions are evident but not characteristic and diagnosis only of pancreatic tumor can be evocated. Therefore digestive angiography is of high diagnostic value in this cases, although histologic examination is necessary to define the metastatic nature of these lesions.

Angiography↗
PubMed1982

[Angioplasty of the arteries of the extremities. Early and mid-term results (up to 3 years) in 492 cases].

Results of iliac, femoral and/or iliac artery percutaneous transluminal angioplasty (P.T.A.) in 492 cases are presented, and the latest technical improvements in the procedure reviewed. Short and medium-term results in iliac artery stenoses were excellent (98 and 96% respectively), obstructions in this region not being treated. The advantage of P.T.A. over surgery is the lack of exposure of patients to the risk of circulatory insufficiency. Very good results were obtained in stenosis of the distal femoral artery, the method being much less effective in cases of long thrombosis. The essential indications are all types of stenosis of limb arteries, while contraindications can be summarized as iliac artery obstructions (because of possible severe retroperitoneal hematomas) and massive atheromatous calcifications. Aortic and graft stenoses are particular indications. Complications are mainly hematomas and thromboses, but these can be reduced in incidence by increasing experience of radiologists in the use of P.T.A. and by improved selection of patients. Progress will also depend on improved control of anticoagulant and thrombolytic treatments. The question is raised as to the need to treat early claudication due to femoral artery stenosis following detection by the Doppler effect test. The essential argument in favor of P.T.A. is the simplicity and safety of the method to the compared reconstructive surgery, a method involving too high a risk.

Aged↗
PubMed1982

[Intraluminal angioplasty in the treatment of femoro-popliteal atheromatous lesions. Apropos of 57 cases].

Close cooperation between radiologist and surgeon is essential to prevent major complications of intra-luminal angioplasty, an only mildly aggressive revascularization procedure. Though evolution of an arteritis of the lower limbs can be halted by relief of the stenosis in some cases, the problem remains as to whether this technique is justified at the stage of claudication, even severe. The wider indications for dilatation at the iliac in relation to the femoropopliteal levels in this most recent series reported, testify this tendency.

Aged↗
PubMed1981

Hitchcock's birds, or the increased rate of exposure to histoplasma from blackbird roost sites.

A statewide survey of populations in proximity to blackbird roost sites to determine exposure to histoplasmosis from such sites has demonstrated that a site harboring Histoplasma capsulatum, even though undisturbed, adds significantly to the exposure rate of proximal populations. Disturbance of such a site increases the exposure rate dramatically with or without concurrent clinical cases of histoplasmosis.

Adult↗
PubMed1980

Survey of knowledge among primary health care workers in diabetes.

The knowledge of diabetes mellitus held by allied health professionals in Kentucky and the short-term and long-term effectiveness of a symposium in altering this knowledge was studied. The groups investigated consisted of: 136 primary health workers (nurses, dieticians, health educators, and other health professionals) surveyed before and after the 12-hour symposium (group 1); 37 of these primary health professionals studied again one year after the first symposium (group 2); and 26 nurses who work at a university hospital, and who did not attend the symposium (group 3). Before training, all groups performed similarly on this survey. Group 1 scored 58.5 +/- 0.2% correct, group 2, 56.9 +/- 3.1% correct, and group 3, 52.7 +/- 5.0% correct. Performance did not correlate with educational level, job description, or geographic location within Kentucky. There was a negative correlation between performance and age for group 1 (r = -0.3494, P < .001). Follow-up studies immediately after the symposium showed that a significant improvement occurred in the performance of group 1 and group 2 on this knowledge survey (correct score +/- SEM = 82.5 +/- 0.3%, and 81.7 +/- 2.4% respectively, P < .005) compared to pretraining scores. A repeat survey of group 2 one year later showed a significant deterioration of knowledge (P < .05), but not to pretraining levels (mean correct score = 69.2 +/- 3.4% at one year versus 56.9 +/- 3.1% before training, P < .02). These results suggest that more emphasis on professional education in diabetes and study of effective methods for providing this education is required.

Adult↗