Biomedical subjects

A Rodriguez

Publications and source records attributed to A Rodriguez.

At least 325 records · Page 18Linked to original sources

PubMed1988

Clinical significance of radionuclide angiographically-determined abnormalities following acute blunt chest trauma.

Abnormalities of right and left ventricular ejection fraction and segmental wall motion may be detected by radionuclide angiography (RNA) following blunt chest trauma. Of 111 patients with blunt chest trauma who were admitted to a large regional shock trauma center and underwent combined first-pass and equilibrium gated RNA, abnormalities were present in 40 (36%). These abnormalities were confined to the right ventricle in 33 patients. There was a positive association between RNA abnormalities and the presence of right bundle branch block (10 of 40, p less than 0.05) and a negative association between RNA abnormalities and the finding of rib fractures (6 of 40, p less than 0.05). The in-hospital death rate of these patients was low (3 of 40 patients with an abnormal RNA and 2 of 71 patients with a normal RNA). Follow-up RNA was performed at 10 +/- 4 days in 26 of the 40 patients with initially abnormal scans, and 22 (85%) of the 26 had reverted to normal. Thus although RNA abnormalities appear common following blunt chest trauma, among patients who survive for more than 24 hours and who undergo subsequent RNA, the complication rate is low despite an abnormal scan. We conclude that routine RNA adds little to clinical management following acute blunt chest trauma.

Adult↗

PubMed1988

Management of major tracheobronchial ruptures in patients with multiple system trauma.

Major tracheobronchial injury presents special problems in the context of multiple system trauma. A 14-year review of a clinical experience revealed eight patients who had operative repair of major bronchial or intrathoracic tracheal injuries. The diagnosis was suspected by subcutaneous emphysema, and especially by persistent pneumothorax or a significant air leak. Bronchoscopy confirmed the diagnosis in all patients before thoracotomy. All eight patients had multiple system injuries. All five with abdominal injuries were hypotensive at admission and underwent celiotomy before thoracotomy. The decision to perform thoracotomy or celiotomy first in patients with major tracheobronchial injuries and concomitant abdominal trauma must be individualized. If both injuries are recognized simultaneously and the patient is hemodynamically unstable but has adequate oxygenation and ventilation, the celiotomy can be performed first. On the contrary, if oxygenation and ventilation are the most threatening problems in a hemodynamically stable patient despite evidence of hemoperitoneum, the bronchial repair should have priority.

Adolescent↗

PubMed1988

IgG4 in human colostrum and human milk: continued local production or selective transport from serum.

Colostrum, mature milk, and paired plasma samples were obtained from 10 postpartum women who had not been previously studied. The geometric mean concentration of IgG4 in colostrum (3.3 micrograms/ml) was similar to the mean concentration in mature milk (3.0 micrograms/ml). The arithmetic mean for the percent of IgG = IgG4 was 10.3 +/- 3.3% for colostrum, 10.3 +/- 3.1% for mature milk, 2.6 +/- 0.3% for early plasma, and 1.7 +/- 0.3% for later plasma. Local mammary production of immunoglobulin was determined by subtracting the estimated serum contribution from the measured concentration in colostrum or milk. Evidence for local mammary production of IgG4 was found in 5 of 10 colostrum samples and 8 of 10 mature milk samples. These observations indicate that the previously observed selective enrichment of IgG4 in colostrum is also true for mature milk. These are the first studies suggesting continued local production of any immunoglobulin other than IgA in mature human breast milk.

Colostrum↗

PubMed1988

Adipose tissue glyceride synthesis in patients with hyperapobetalipoproteinemia.

Adipose tissue was obtained at thoracotomy in five control patients with valvular heart disease, all of whom were free of coronary artery disease and all of whom were normolipidemic with normal low density lipoprotein apolipoprotein B levels, and eight patients with coronary artery disease, all of whom had hyperapobetalipoproteinemia. In both groups, the rates at which linoleic acid and palmitic acid were incorporated into diglyceride and triglyceride were determined in vitro. The data indicate that fatty acid incorporation into adipose tissue glycerides was twice as rapid in controls as in patients with hyperapobetalipoproteinemia. By contrast there was no difference between the groups in the rate of net lipolysis of adipocyte glyceride. The data at hand do not establish the mechanism responsible for the difference in synthesis between normal subjects and patients with hyperapobetalipoproteinemia, but this may explain the delayed chylomicron triglyceride clearance previously observed in the disorder.

Adipose Tissue↗

PubMed1988

Morphology of the lumbar vertebral canal.

In a series of 215 anteroposterior X-ray films, a study was made of the horizontal distance between the pedicles of each lumbar vertebra, first of all sequentially, describing the morphology adopted by the lateral limits of the canal, and secondly determining the absolute value for each level separately and in relation to the variables of sex and age. The absolute value of this distance at each level is related to the thickness of the pedicles and the width of the vertebral bodies of L3 and L4. The values obtained were tested with the appropriate statistics in each case.

Adult↗

PubMed1988

Mediastinal tumors presenting as spontaneous hemothorax, simulating aortic dissection.

The usual causes of hemomediastinum and hemothorax include chest trauma, rupture of an aortic aneurysm or aortic dissection. We report two patients who presented with a clinical picture of aortic dissection. In both patients, the chest radiograph revealed anterior mediastinal masses. Aortic dissection could not be excluded on the basis of the chest radiograph, and additional investigation by thoracic aortography was performed. The tumors had undergone spontaneous bleeding into the mediastinum and the pleural space, presumably causing the patients pain. The interesting and unusual causes of spontaneous hemomediastinum and hemothorax are reviewed.

Adult↗

PubMed1988

A randomized trial of tamponade or sclerotherapy as immediate treatment for bleeding esophageal varices.

Sengstaken-Blakemore tamponade is used for the initial control of bleeding esophageal varices (BEV), although it is known to be potentially dangerous. Sclerotherapy has been shown to be effective in the treatment of BEV. This trial has been designed to evaluate comparatively the effectiveness of both procedures in the initial control of the hemorrhage. Forty-three patients with BEV were included in the trial. Twenty patients (group SB) were treated by tamponade. Twenty-three patients (group ST) were treated by sclerotherapy by means of a simple technique. During the first 24 hours, hemostasis was obtained in 16 of the SB patients and in all 23 of the ST patients (p less than 0.05). At seven days, nine SB patients and 19 ST patients were free of hemorrhagic relapse (p less than 0.05). By stratifying in relation to hepatic failure, the difference was greater (p less than 0.005) if patients with Child's A classification were excluded. It is concluded that sclerotherapy should be undertaken in almost every instance at the same moment that diagnosis is made, bypassing the intermediate step of tamponade.

Balloon Occlusion↗

PubMed1988

Recovery from potentially lethal damage and recruitment time of noncycling clonogenic cells in 9L confluent monolayers and spheroids.

Cells that have been grown as multicell tumor spheroids exhibit radioresistance compared to the same cells grown in monolayers. Comparison of potentially lethal damage (PLD) repair and its kinetics was made between 9L cells grown as spheroids and confluent monolayers. Survival curves of cells plated immediately after irradiation showed the typical radioresistance associated with spheroid culture compared to plateau-phase monolayers. The dose-modification factor for spheroid cell survival is 1.44. Postirradiation incubations in normal phosphate-buffered saline (PBS), conditioned media, or 0.5 M NaCl in PBS reduced the differences in radiosensitivity between the two culture conditions. Postirradiation treatment in PBS or conditioned medium promoted repair of potentially lethal damage, and 0.5 M NaCl prevented the removal of PLD and allowed the fixation of damage resulting in lower survival. Survival of spheroid and monolayer cells after hypertonic NaCl treatment was identical. NaCl treatment reduced Do more than it did the shoulder (Dq) of the survival curve. PLD repair kinetics measured after postirradiation incubation in PBS followed by hypertonic NaCl treatment was the same for spheroids and for plateau-phase monolayers. The kinetics of PLD repair indicates a biphasic phenomenon. There is an initial fast component with a repair half-time of 7.9 min and a slow component with a repair half-time of 56.6 min. Most of the damage (59%) is repaired slowly. Since the repair capacity and kinetics are the same for spheroids and monolayers, the radioresistance of spheroids cannot be explained on this basis. Evidence indicates that the time to return from a Go (noncycling G1 cells) state to a proliferative state (recruitment) for cells from confluent monolayers and from spheroids after dissociation by protease treatment may be the most important determinant of the degree of PLD repair that occurs. Growth curves and flow cytometry cell cycle analysis indicate that spheroid cells have a lag period for reentry into a proliferative state. Since plating efficiency remains high and unchanging during this period, one cannot account for the delay on the basis of the existence of a large fraction of Go cells which are not potentially clonogenic. The cell cycle progression begins in 6-8 h for monolayer cells and in 14-15 h for spheroids. It is hypothesized that the slower reentry of spheroid cells into a cycling phase allows more time for repair than for the rapidly proliferating monolayer cells.

Animals↗

PubMed1987

Low density lipoprotein (LDL) inhibits histamine release from human mast cells.

We examined the effect of low density lipoprotein (LDL) on histamine release from purified human lung mast cells. LDL inhibited anti-IgE- induced histamine release in a dose-dependent manner, with 100 micrograms/ml LDL-protein inhibiting histamine release by 53 +/- 8% (mean +/- SEM); half-maximal inhibition occurred at 40-80 micrograms/ml. LDL also inhibited calcium ionophore A23187-induced histamine release in a dose-dependent manner, with 1 mg/ml of LDL inhibiting histamine release by 83 +/- 9%; half maximal inhibition occurred at 220-280 micrograms/ml. Inhibition by LDL was time-dependent: half-maximal inhibition of anti-IgE- induced histamine release by LDL occurred at 30-50 minutes of incubation. The inhibitory effect of LDL was independent of buffer calcium concentrations (0-5 mM) or temperature (0-37 degrees C). These data are consistent with a newly defined immunoregulatory role for LDL.

Calcimycin↗

PubMed1987

Complications of clear lens extraction in axial myopia.

Clear lens extraction is a refractive surgery used to compensate axial myopia. Formerly, intracapsular lens extraction was performed, but the present surgical method is extracapsular lens extraction or phacoemulsification. Clear lens extraction is becoming controversial because of the danger of complications. We retrospectively reviewed the postoperative complications in 33 eyes of 20 patients who underwent clear lens extraction at other institutions between 1966 and 1984. Twelve patients (60%) had motility disturbances. Eight (24%) of 33 eyes suffered secondary glaucoma; ten (30%), retinal detachment; 12 (36%), lens remnants in the pupillary space; and six (18%), blindness caused by clear lens extraction or by additional surgery performed by us while attempting to improve a poor prognosis. Clear lens extraction appears to be contraindicated in the young, in those with axial diameters greater than 29 mm, and in those presenting with peripheral chorioretinal degeneration. Moreover, clear lens extraction does not avoid the progression of myopia at the posterior segment. We suggest the use of safer, noninvasive, reversible alternatives.

Adult↗

PubMed1987

Effect of theophylline on ion transport in the lizard colon.

1. The effect of theophylline on ion transport was examined using an in vitro short-circuited preparation of lizard colon. 2. Theophylline increased short circuit current (Isc) and transmural potential difference (PD). This increase caused by theophylline was accompanied by a small increase in transmural conductance (Gt). 3. Theophylline did not inhibit the absorption of Na+ but reversed Cl- absorption to secretion. This latter effect was due to an increase of the serosal-to-mucosal flux of Cl-. 4. Ion substitution experiments revealed that the effect of theophylline was Na+- and HCO3(-)-dependent and that these ions were required in the bathing solution. 5. These results with lizard colon are compared with those reported for mammalian colon and the mechanism of theophylline-induced Cl- secretion in these epithelia is discussed.

Animals↗

PubMed1987

Intestinal glucose and galactose transport in the cultured gilthead bream (Sparus aurata).

1. Electrical parameters and transepithelial glucose and galactose transport were determined in vitro across anterior and posterior intestine of the culture fish Sparus aurata. 2. Electrical potential difference (PD) and short-circuit current (Isc) were serosa-positive in anterior intestine, while they were serosa-negative or near zero in posterior intestine. 3. Tissue conductance (Gt) was higher in posterior than in anterior intestine. In both parts it was decreased when the Na ion was omitted in mucosal and serosal reservoirs. 4. Addition of glucose or galactose to the mucosal side of intestine caused an increase in PD and Isc in posterior intestine but did not significantly change PD and Isc in anterior intestine. 5. Isotopic flux of glucose and galactose measurements in short-circuit conditions showed a net active glucose and galactose absorption in posterior intestine, while in anterior intestine active transport of glucose or galactose was not observed. 6. The net transport of glucose and galactose in posterior intestine was decreased to zero in the absence of Na in mucosal and serosal reservoirs or in the presence of ouabain (1 mM) in serosal solution.

Animals↗

PubMed1987

Skin flap neovascularization by means of a vasodilator.

The viability of vascularized flaps depends mainly on good microsurgical technique, although several factors can affect the final outcome. There are few studies of neovascularization at the recipient site and its significant role in late vascular occlusion. In this study, the rat abdominal skin flap based on circulation through the epigastric vessels was used, to study a drug with vasodilator effects (isoxsuprine) and its relation to flap neovascularization. By ligating the epigastric artery from one to five days after raising the flap, good results in flap viability were statistically significant when isoxsuprine was used. At two, three, and four day arterial occlusion after flap elevation, faster and more neovascularization occurred with isoxsuprine, when compared to control groups. The study strongly suggest that isoxsuprine hastens neovascularization time in the rat model.

Animals↗

PubMed1987

Effect of fasting on amino acid metabolism by lactating mammary gland: studies in women and rats.

Concentrations of free amino acids were measured in human milk and arterial blood from lactating women after an overnight fast or after a controlled breakfast. The concentrations of many free amino acids in milk (except L-tyrosine, L-aspartate, L-asparagine, L-glutamate and L-glutamine) were lower after an overnight fast than after breakfast. Similarly, the arterial concentrations of amino acids were lower except for L-asparagine, L-alanine, L-tyrosine and L-phenylalanine. Net uptake of amino acids by the mammary gland of the lactating rat was significantly lower after starvation for 6 or 24 h than in the fed state because the arteriovenous differences of amino acids and the blood flow were significantly lowered. Starvation produced a significant decrease of 2-amino-[1-14C]isobutyric acid uptake by isolated acini from lactating rat. These results show that short-term starvation decreases the amino acid supply and transport in mammary gland as well as the free amino acid concentration in milk.

Amino Acids↗

PubMed1987

Blunt thoracic trauma. Analysis of 515 patients.

A retrospective analysis of 515 cases of blunt chest trauma is presented. The overall thoracic morbidity rate was 36% and mortality rate was 15.5%. Atelectasis was the most common complication. Severe chest trauma can be present in the absence of rib or other thoracic bony fractures. Emergency thoracotomies for resuscitation of the patient with blunt chest trauma with absent vital signs proved unsuccessful in 39 of 39 patients. A high index of suspicion for blunt chest injury occurring in blunt trauma, coupled with an aggressive diagnostic and therapeutic approach, remains the cornerstone of treatment to minimize the morbidity and mortality of such injuries.

Adolescent↗

PubMed1987

Spontaneous pulmonary torsion.

A patient with systemic manifestations of sepsis after above-knee amputation developed massive left pulmonary atelectasis and pneumonia. These persisted despite repeated bronchoscopies. At thoracotomy, 180 degrees torsion of the left lung was found. The patient improved temporarily but died later of sepsis, probably related to severe hip osteomyelitis.

Aged↗

PubMed1987

Role of CT in excluding major arterial injury after blunt thoracic trauma.

The role of CT in the diagnosis of major vascular rupture following blunt decelerating chest trauma is controversial. Its value in excluding major arterial injury has not yet been determined. During a 12-month period we obtained dynamic enhanced thoracic CT studies in 20 patients with blunt decelerating thoracic trauma who had abnormal or equivocal mediastinal contours on chest radiographs. In all cases diagnosis was confirmed by either digital subtraction (18 patients) or conventional thoracic angiography (two patients). CT scans showed evidence of direct aortic injury in three patients and evidence of mediastinal hematoma in five others. Four of these eight patients had major arterial injury verified angiographically and at surgery. In two patients the CT scan was considered equivocal; both patients had normal thoracic angiograms. CT excluded direct vascular injury or mediastinal hematoma in 10 patients. All 10 had normal thoracic angiograms. This preliminary study suggests that, in patients sustaining blunt decelerating thoracic trauma, thoracic CT may be more valuable than chest radiography in excluding major vascular injury and, in some cases, may reduce the need for thoracic angiography.

Adolescent↗

PubMed1987

Prospective study of scheduled withdrawal from nortriptyline in children and adolescents.

Thirty 6- to 16-year-old subjects were gradually tapered from their maintenance dose of nortriptyline while being monitored for withdrawal effects. Five subjects had brief gastrointestinal distress that did not require the administration of an extra dose. The results of this open study suggest that scheduled tapering of nortriptyline will preclude withdrawal symptoms in most pediatric patients.

Adolescent↗