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Biomedical subjects

E Cruz

Publications and source records attributed to E Cruz.

At least 55 records · Page 3Linked to original sources
PubMed1990

Measurement of arterial pressure after cardiopulmonary bypass with long radial artery catheters.

Radial arterial pressure can significantly underestimate central aortic pressure in the postcardiopulmonary bypass (post-CPB) period. At the study institution, routine monitoring of perioperative arterial pressure in adult patients undergoing cardiac surgery is performed with a long radial artery catheter with the distal end positioned in the subclavian artery. In 68 patients presenting for elective cardiac surgery, both a conventional short radial artery catheter and a contralateral long radial artery catheter were placed. Analysis of radial and subclavian arterial pressures post-CPB in the first 47 patients showed average maximum differences of 7 mm Hg systolic and 4 mm Hg mean. In 15% of patients, the differences were clinically significant (greater than 20 mm Hg systolic and/or greater than 14 mm Hg mean). In 28 patients, central aortic pressure was measured post-CPB, and subclavian artery pressure was found to be an excellent estimator of central aortic pressure. There were no significant complications related to using long radial artery catheters in the 68 patients who were followed prospectively. Monitoring subclavian arterial pressure by percutaneous insertion of a long radial artery catheter provides a reliable estimation of central aortic pressure, even in patients with significant radial artery-to-central aortic pressure gradients post-CPB.

Adult↗
PubMed1989

Dietary myo-inositol effect on sugar cataractogenesis.

The lens myo-inositol (MI) content is known to be depleted during initial cataractogenesis in both streptozocin (STZ)-induced diabetic and 50% galactose-maintained rats. The objective of this study is to establish whether dietary MI supplementation protects lens transparency, MI content and individual fiber cell ultrastructure is both model systems of sugar cataract. In the diabetic study, after induction with STZ, rats were immediately placed on normal chow supplemented with 2% MI for 14 weeks while additional age-matched control and diabetic rats remained untreated. Within 14 weeks, untreated diabetic rat lenses were totally opaque with undetectable MI content; MI was undetectable by 1 month. These opaque lenses were devoid of fiber cells and exhibited only acellular, amorphous cortical regions between 0 and 500 microns from the capsule. In contrast, 14-week, MI-treated diabetic rat lenses exhibited only cortical vacuolation indicative of initial cataractogenesis; MI content was 0.41 +/- 0.26 mumol/g wet weight of lens. Scanning electron micrographs indicated a granulated, acellular region subadjacent to the capsule and confirmed the presence of cortical fiber cells, approximately 100 microns from the capsule. In 50% galactose-maintained rats, daily administration of MI for 1 month was unable to prevent total opacification or reverse initial cataractogenesis indicating that in rapidly progressing galactose cataracts, MI was unable to protect lens transparency, MI content and cortical fiber ultrastructure. The combined results suggest that MI may exert a protective effect on the slowly developing diabetic cataract. Of the 2 models, the time course and polyol content in STZ diabetic lenses more closely correlate to the human diabetic lens which has a low activity of aldose reductase; therefore, it is possible that MI may exert a protective effect in human diabetic cataract.

Animals↗
PubMed1988

Reversal of proteinuria by sorbinil, an aldose reductase inhibitor in spontaneously diabetic (BB) rats.

Sorbinil, an aldose reductase inhibitor, was examined as a therapeutic agent to arrest and/or reverse proteinuria in 'type 1' insulin-dependent BB rats having spontaneous diabetes mellitus. Prior to sorbinil treatment, diabetic rats exhibited hyperglycemia and increased urinary excretion of urobilinogen, glucose and protein. To assess proteinuria, 24-hour urine samples were analyzed for both total protein and individual components between 30,000 and 100,000 daltons. Daily oral administration of sorbinil (20 mg/kg body weight) was initiated and the aforementioned parameters reevaluated after 1, 2 and 4 months. Results indicated that after 1 month of sorbinil treatment, urobilinogen was normalized in all diabetic BB rats (n = 12), whereas urinary protein excretion was either diminished (67%) or remained constant (16%), despite persistence of hyperglycemia and glycosuria. These therapeutic effects were sustained after 2 months of sorbinil treatment. After 4 months, protein excretion was normalized (6.56 +/- 3.34 mg/24 h), despite persistence of hyperglycemia and glycosuria (n = 12); in marked contrast, 6 untreated rats continued to exhibit proteinuria (17.76 +/- 2.59 mg/day). Sorbinil diminished albumin and a series of urinary proteins between 30,000 and 100,000 daltons, suggesting that sorbinil may represent a therapeutic approach to manage diabetic nephropathy as indicated by diminution of proteinuria.

Aldehyde Reductase↗
PubMed1988

Proteinuria associated with hypertension and diabetes mellitus.

Proteinuria, a complication of both diabetes mellitus and hypertension, was compared in 2 genetically induced models: insulin-dependent diabetic BB rat (BB), and Okamoto-Aoki spontaneously hypertensive Wistar rats (SHR). Both disease states were clearly distinguished from each other and their respective age-matched controls by analysis of 24-hour urine samples for glucose, urobilinogen, bilirubin and total protein. Then individual protein components between 15,000 and 120,000 daltons were separated by molecular weight and quantitated by laser densitometric analysis. The results indicated that insulin-dependent diabetic BB rats excreted urine having elevation of glucose (100-250 mg/dl), bilirubin (0.05 +/- 0.03 mg/dl) and urobilinogen (6.6 +/- 3.8 Ehrlich units/dl) in contrast to all age-matched SHR and normotensive Wistar-Kyoto (WKY) and nondiabetic controls, which excreted urine having normal urobilinogen and no detectable glucose or bilirubin. Both SHR and insulin-dependent BB rats exhibited proteinuria, urinary protein excretion being increased approximately 4-5 times that of their age-matched controls. BB rats excreted 18.80 +/- 2.62 mg protein/day attributed to an increase in albumin and an entire array of proteins between 30,000 and 120,000 daltons not present in controls which primarily excreted proteins below 20,000 daltons. In the SHR, proteinuria did not include an array of proteins; the increase in excreted protein (39.20 +/- 16 mg/day) was primarily attributed to albumin and another protein having a higher molecular weight. The SHR urinary proteins were similar to proteins excreted by streptozocin-induced, noninsulin-dependent diabetic rats treated with the aldose reductase inhibitor sorbinil. If hypertension is associated with diabetic nephropathy, our preclinical results suggest that coadministration of sorbinil with antihypertensive therapy may promote a positive synergistic effect further diminishing proteinuria.

Animals↗
PubMed1988

Weekly cuirass ventilation improves blood gases and inspiratory muscle strength in patients with chronic air-flow limitation and hypercarbia.

We studied the effects of an 8-h, once-a-week schedule of cuirass ventilation (CV) in 5 patients with advanced chronic air-flow limitation and chronic hypercarbia (PaCO2, 58.6 +/- 10.1 mm Hg; mean +/- SD). Repeated measurements of arterial blood gases, maximal inspiratory mouth pressure (P1max), 12-min walking distance, and respiratory cycle were performed during a 1-month run-in period. Quality of life and transdiaphragmatic pressure were measured once. All patients completed the planned 4-month study. Four of them were ventilated for longer periods because CV could not be discontinued at the end of the study. PaCO2 showed a significant fall starting during the first month; PaO2 significantly increased from the second month, whereas P1max significantly rose from the third month on. Maximal transdiaphragmatic pressure increased in the 2 patients with abnormal baseline values. The fall in PaCO2 was associated with an increase in tidal volume because of a longer inspiratory time. Significant improvements in quality of life and in the 12-min walking distance were observed. We conclude that weekly CV improves blood gases, inspiratory muscle strength, and clinical conditions of patients with chronic air-flow limitation and chronic hypercarbia, probably because of correction of chronic inspiratory muscle fatigue.

Blood Gas Analysis↗
PubMed1986

Diminished proteinuria in diabetes mellitus by sorbinil, an aldose reductase inhibitor.

Proteinuria was diminished by concomitant oral administration of sorbinil, an aldose reductase inhibitor to streptozotocin-induced diabetic rats. Animals were placed in one of three groups: control, diabetic, sorbinil-treated diabetic. For a period of 10 weeks, 24-hour urine samples were analyzed weekly for volume, glucose, ketone, total protein (Pesce-Strande) and individual protein components having molecular weights between 15,000 and 120,000 daltons. The latter were examined by polyacrylamide gel electrophoresis and quantitated by laser densitometric analysis. Results indicated that controls excreted albumin (68,000 daltons) and low-molecular weight proteins between 15,000 and 20,000 daltons. Throughout the 10-week period of diabetes, there was a 7- to 12-fold increase in total urinary protein excreted in 24 h. Diabetic-induced proteinuria primarily resulted from excretion of newly detected proteins having molecular weights of 30,000-100,000 daltons and an increase amount of albumin. Sorbinil treatment prevented approximately 70% of the increase in total protein excretion despite persistent hyperglycemia, glycosuria and ketonuria. Laser densitometric analysis indicated that the aldose reductase inhibitor decreased by 70% the excretion of newly detected proteins and albumin while maintaining the 15,000- to 20,000-dalton proteins. These results suggest that the polyol pathway is implicated in diabetic-induced proteinuria and inhibition of aldose reductase may represent a therapeutic approach for management of diabetic nephropathy.

Aldehyde Reductase↗
PubMed1986

Inspiratory muscle function in unilateral diaphragmatic paralysis.

Pulmonary function has been extensively studied in unilateral diaphragmatic paralysis (UDP), but there is scarce information regarding inspiratory muscle function in this condition. We therefore studied inspiratory muscle function in 8 patients with UDP (Group 1: age 48.3 +/- 2.1 yr of age, means +/- SD) as well as in 7 patients with UDP and concomitant cardiopulmonary disease (Group 2: 60.6 +/- 13 yr of age). Twelve young normal subjects were also studied (32.3 +/- 7.7 yr of age). Maximal static transdiaphragmatic and inspiratory mouth pressure were measured at FRC. Gastric (Pga), esophageal (Pes), and transdiaphragmatic (Pdi) pressure swings were measured during quiet breathing. There was no difference in inspiratory muscle function in left-sided versus right-sided UDP. Paradoxical gastric pressure swings were observed in 4 patients from Group 1 and in 5 from Group 2. In 2 patients from Group 1 and 1 from Group 2, Pga did not change during quiet breathing. In the remaining 3 patients, Pga swings were similar to those observed in the normal subjects. Maximal Pdi was reduced in half of the patients from Group 1 and in all of the patients from Group 2. Maximal inspiratory pressure was below normal values in 2 patients from Group 1 and in all patients from Group 2. We conclude that unilateral diaphragmatic paralysis is associated with an abnormal pattern of use of respiratory muscles during quiet breathing, characterized by the use of intercostal and accessory inspiratory muscle or compensatory use of abdominal expiratory muscles. Inspiratory muscle strength was impaired in some of the patients, and it worsened when cardiopulmonary disease was present.

Adult↗
PubMed1986

Gastrointestinal complications in critically ill patients: the intensivists' overview.

The critical care environment may be characterized by invasive monitoring, vasoactive drugs, and major interventions which may have adverse effects on gastrointestinal function. Furthermore, conditions such as heart failure or sepsis may compromise oxygen delivery to gastrointestinal organs. Life threatening illness from a variety of causes may produce endoscopically evident gastritis or ulceration in up to 100% of patients, and clinically evident bleeding in 20%. Clinical studies suggest that antacids or H2 receptor blockers may reduce the frequency of this complication. Other conditions are associated with a spectrum of hepatic dysfunction ranging from the cholestatic jaundice of reactive hepatopathy during sepsis to centrilobular necrosis and hepatitis of shock liver. Additionally, many drugs used in the critical care setting may adversely affect mesenteric oxygen delivery and result in ischemia or infarction of the bowel. An increased awareness and understanding of these and other gastrointestinal complications in critically ill patients will, it is hoped, lead to earlier detection and better therapy than is now available.

Animals↗
PubMed1985

Reversal of stage-I sugar cataract by Sorbinil, an aldose reductase inhibitor.

Aldose reductase is implicated in the pathogenesis of sugar cataracts; therefore, inhibition of this enzyme subsequent to cataractogenesis may represent a therapeutic approach for the restoration of lens physiology despite the persistence of diabetes or galactosemia. In the present study, the effect of aldose reductase inhibition subsequent to stage-I cataract formation was investigated in the galactose-maintained rat. Our results indicated that despite continuation of galactose feeding the aldose reductase inhibitor, Sorbinil, a spirohydantoin, arrested further progression and promoted a reparative process. Quantitative analysis of scanning electron micrographs indicated that the afflicted lens regions were contained and their cellular components stabilized with regard to fiber hydration and interdigitation. The reparative process involved: decrease in lens dulcitol, gradual recovery of fiber thickness and partial restoration of lens myo-inositol content. At this stage of cataractogenesis, despite continuance of galactose feeding, the effects of Sorbinil treatment were comparable to the reparative process achieved by restoration of a normal diet.

Aldehyde Reductase↗
PubMed1985

Synergism of sorbinil and normal diet on reversal of stage-II sugar cataract.

Sorbinil, an aldose reductase inhibitor, in combination with diet normalization, arrested stage-II galactose cataract and restored lens transparency. During the reversal process, determination of lens dry weight, dulcitol and myo-inositol content as well as individual fiber cell ultrastructure offered a comprehensive index of lens integrity. In this study, young rats received a 50% galactose diet for 10 days to produce a stage-II sugar cataract. Then they were placed on one of the following diets: 50% galactose and Sorbinil (20 mg/kg); 50% galactose; normal diet, normal diet and Sorbinil (20 mg/kg). From each group, equal numbers were sacrificed at 5, 10 and 20 days. Although differences were obtained after 5 and 10 days, the 20-day reversal period provided the most significant findings. Only the combination of Sorbinil and normal diet restored lens transparency, normalized lens myo-inositol content and dry weight and partially restored fiber cell integrity as evidenced by diminished granulation and increased fiber synthesis. Neither Sorbinil treatment during galactose administration nor normal diet alone were sufficient to protect against further cataractogenesis, thus indicating a synergistic effect of Sorbinil in combination with normal diet.

Aldehyde Reductase↗
PubMed1985

Inspiratory muscle function in patients with severe kyphoscoliosis.

In 9 patients with severe kyphoscoliosis we studied inspiratory muscle function by measuring transdiaphragmatic pressure (Pdi) and its components: gastric (Pga) and esophageal (Pes) pressures during quiet breathing. Maximal Pdi and maximal inspiratory mouth pressure (Pimax) were also measured. The results showed that Pimax and Pdimax were significantly lower in patients than in normal subjects. During quiet breathing, all patients had positive swings in Pga, indicating an active contraction of the diaphragm, but Pes was significantly more negative, suggesting the recruitment of intercostal and accessory inspiratory muscles. We did not find significant correlations between Pimax, Pdimax, delta Pga/delta Pes, FVC, PaO2, or PaCO2 and the degree of spinal deformity. The FVC tended to correlate with Pimax (r = 0.63) and with Pdimax (r = 0.53). The Pdi correlated with PaO2 (r = 0.66) and with PaCO2 (r = -0.76; p less than 0.05). A significant correlation was also observed between Pimax and PaO2 (r = 0.785; p less than 0.05) and between Pimax and PaCO2 (r = -0.86; p less than 0.01). We conclude that impairment of inspiratory muscle function is related to the development of ventilatory failure in kyphoscoliosis.

Adult↗
PubMed1985

Reversal of diabetic cataract by sorbinil, an aldose reductase inhibitor.

Aldose reductase is implicated in the pathogenesis of diabetic cataracts; therefore, inhibition of this enzyme subsequent to cataractogenesis may represent a therapeutic approach for restoration of lens physiology. In the present study, the effect of aldose reductase inhibition subsequent to stage I cataract formation was investigated in the streptozocin-induced diabetic rat. Our results indicated that the aldose reductase inhibitor sorbinil, a spirohydantoin, arrested further progression and promoted a reparative process despite continuation of hyperglycemia and elevated lens glucose. Quantitative analysis of scanning electron micrographs indicated that the afflicted lens regions were contained and their cellular components stabilized with regard to fiber hydration and interdigitation. The reparative process included: normalization of lens sorbitol, gradual recovery of existing fiber contour and interdigitation, production of new fibers, and partial restoration of lens myo-inositol content.

Aldehyde Reductase↗