Search PubMed⌕ Search

Biomedical subjects

C Cruz

Publications and source records attributed to C Cruz.

At least 109 records · Page 6Linked to original sources

Evaluation of MicroScan rapid gram-positive panels for detection of oxacillin-resistant staphylococci.

The ability of MicroScan rapid panels (Baxter MicroScan, West Sacramento, Calif.) to detect oxacillin resistance in 92 clinical isolates of Staphylococcus aureus and 103 coagulase-negative staphylococci was evaluated by comparing results with those of MicroScan 24-h MIC panels and, to resolve discrepancies, oxacillin agar screening. Both panels were interpreted by the MicroScan WalkAway-96 system. Rapid panels detected 96.7% of resistant S. aureus isolates and 72% of resistant coagulase-negative staphylococci, 22 of which did not grow in the panels.

Coagulase↗

Copper and zinc metabolism in aminonucleoside-induced nephrotic syndrome.

Copper (Cu) and zinc (Zn) were measured in urine, serum and tissues from rats with nephrotic syndrome (NS) induced with a single subcutaneous dose of puromycin aminonucleoside (PAN; 15 mg/100 g BW). Control animals were pair-fed. Urine was collected daily, and the rats were sacrificed on day 10. PAN-nephrotic rats had proteinuria (days 3-10), high urinary Cu (days 1, 2, 4-10) and Zn (days 3-10) excretion. On day 10, nephrotic rats had: (a) albuminuria, hypoalbuminemia, hypoproteinemia, high urine and low serum levels of ceruloplasmin; (b) low Cu and Zn serum levels; (c) high clearance and fractional excretion of Cu and Zn, and (d) low kidney and liver Cu content and essentially normal tissue Zn levels. The alterations in Cu metabolism were more intense than those in Zn metabolism. Urine Cu and Zn showed a positive correlation with urine total protein on days 3-10 which suggests that high urinary excretion of Cu and Zn may be due to the excretion of its carrier proteins. In conclusion, these rats did not show a typical Zn deficiency but a clear decrease in Cu in the liver and kidney.

Animals↗

Abnormalities of coagulation in experimental nephrotic syndrome.

The human nephrotic syndrome is accompanied by important alterations of the coagulation system related proteins. The purpose of the present study was to examine the activity of coagulation- and fibrinolysis-related proteins in plasma and urine of control and puromycin aminonucleoside injected rats on days 2 (prenephrotic stage) and 10 (nephrotic stage). We measured the prothrombin time (PT), the activated partial thromboplastin time (aPTT), and the activities of (1) the coagulation factors (CFs) I, II, V, and VII-XII; (2) the inhibitor of coagulation antithrombin III (ATIII), and (3) the component of the fibrinolytic system alpha 2-antiplasmin (alpha 2-APL). PT and aPTT and the activities of CF, ATIII, and alpha 2-APL were not measurable in the urine of control and puromycin amino-nucleoside injected rats on day 2. On this same day, plasma ATIII and CF VIII decreased. On day 10 (1) PT and aPTT decreased in plasma and were not measurable in urine; (2), plasma CFs I, II, V, VII, VIII, X, and XI increased; (3), plasma ATIII decreased; (4), plasma CFs IX and XII and alpha 2-APL did not change, and (5) ATIII and CFs II, VII, VIII, IX, X, XI, and XII, but not CFs I and V and alpha 2-APL, appeared in urine on day 10. ATIII deficiency was secondary probably to the urinary losses; however, the plasma activity of CFs II, VII, VIII, X, and XI increased and that of CFs IX and XII remained unchanged in spite of their urinary losses which suggests that other mechanisms such as deranged catabolism and altered hepatic synthesis may be involved.(ABSTRACT TRUNCATED AT 250 WORDS)

Albuminuria↗

[Teaching of health economics in Mexico: 5-year experience].

Teaching strategies for a new specialty constitute a challenge to ensure the rapid development of human resources for the purpose of supporting these activities. In the health economics field a plan was applied for coping with the needs of teaching activities in the field. The activities developed in the plan are presented in this paper, included under the following items: A. Theoretical organization of the contents of the subject. B. Organization of contents according to the students' needs. C. Support given to teachers. D. The whole strategy also includes: academic interchange, technical advisory services, dissemination of results through meetings, publications and academic organizations. E. Median term agenda: Human resources; Financial resources; Teaching strategies; Interaction between health services and decision makers; and Collaborative network.

Curriculum↗

Consequences of the North American Free Trade Agreement for health services: a perspective from Mexico.

OBJECTIVES: The purposes of the study were to assess the potential impact of the North American Free Trade Agreement (NAFTA) on medical care in Mexico and to identify internal measures Mexico could take to increase the benefits and minimize the risks of free trade. METHODS: The dual nature of the health sector is examined; the Mexican, Canadian, and US health care systems are compared; and modes and consequences of international exchange of health services are analyzed. RESULTS: Four issues require immediate attention: accreditation of health care facilities, licensing and certification of professionals, technology assessment, and financial equity. CONCLUSIONS: NAFTA offers opportunities for positive developments in Mexico, provided risks can be anticipated and preventive measures can be taken to avoid negative impacts on the health system. Medical services, like other elements of the Mexican economy, must be modernized to respond to the demands of global competition. The Mexican National Academy of Medicine has recommended to the Mexican government (1) internal strengthening of the Mexican health care system to improve its ability to respond to the new conditions created by NAFTA and (2) a gradual process to facilitate equitable and mutually beneficial interactions among the three countries.

Canada↗

Role of the renin-angiotensin system in arterial hypertension secondary to acute unilateral urinary obstruction.

Acute unilateral ureteral obstruction (AUUO) has been associated to a blood pressure increase, presumably secondary to activation of the renin-angiotensin system (RAS), since the obstructed kidney increases renin secretion (Ref. 8). In an attempt to delineate the role of the RAS in this hypertensive model, we acutely obstructed the ureter in two groups of dogs that previous to the obstruction received either placebo (G I, n = 8) or 50 mg of captopril, an angiotensin-converting enzyme inhibitor (G II, n = 9). Animals that received placebo showed a consistent increase in mean arterial pressure (MAP), 128 +/- 4 vs. 144 +/- 4 mm Hg (p < 0.001); those that received captopril did not show such a tendency: 135 +/- 7 vs. 135 +/- 7 mm Hg. In further studies, three groups of animals were included: group III (G III, n = 4), identical to G I except that plasma renin activity (PRA) and aldosterone (ALDO) were measured; Group IV (G IV, n = 5), identical to G II except that they received 50 mg of indomethacin, 60 min before captopril; and group V (G V, n = 6), which was sham operated and measured for PRA and ALDO.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗

Naphtyl methyl imidazoline (NMI) membranes interactions: NMR study and evaluation of possible radioprotective consequences.

The interactions of the radioprotective molecule Naphtyl methyl imidazoline (NMI) with membranes have been studied using biophysical and biochemical methods. 1H, 2H and 31P-NMR methods showed a strong interaction with the deep part of the layer of model membranes inducing the formation of a new membrane compartment. These properties are not involved in the radioprotection effect of NMI which is more probably due to its vasoconstrictive properties.

Humans↗

High dosage vitamin E effect on oxidative status and serum lipids distribution in streptozotocin-induced diabetic rats.

This study was performed to determine whether vitamin E supplementation in streptozotocin-induced diabetic rats treated by insulin could reduce serum oxidation markers (malondialdehyde: MDA, Schiff bases, anti-protein-MDA adduct antibodies) and modulate lipid changes. After 10 weeks, diabetes induced in rats a significant increase in Schiff bases (P < 0.006) and anti-protein-MDA adduct antibodies (P < 0.01). These alterations were accompanied by a significant rise in serum free fatty acids (225%), triglycerides (35%), and phospholipids (30%) and changes in fatty acid distribution in these fractions and in cholesterol esters. Vitamin E supplementation in diabetic rats reduced Schiff bases and anti-protein-MDA adduct antibodies and tended to restore the fatty acid profile close to control rats without decreasing quantitatively serum lipids enhanced by diabetes. Concerning fatty acids, vitamin E chiefly reduced stearic acid (C18:0) in free fatty acids, cholesterol esters, and phospholipids and cancelled the decrease in low molecular triglycerides observed in diabetic rats. Furthermore, vitamin E maintained the ratio of monounsaturated and polyunsaturated fatty acids, particularly with respect to oleic acid (C18:1), dihomo-gamma-linolenic acid (C20:3 n-6), eicosapentaenoic (C20:5 n-3), and docosapentaenoic acid (C22:5 n-3), in serum phospholipids. These changes observed in vitamin E supplemented rats, compared to vitamin E-untreated diabetic rats, could favor prevention of accelerated atherogenesis. Particularly, the decrease of serum peroxides and enhancement in phospholipid fatty acids (C20:3 n-6, C20:5 n-3, and C22:5 n-3) could induce the preferential formation of prostaglandins (PGE1, PGI2, PGI3) which are protective in cardiovascular diseases.

Animals↗

The galea frontalis myofascial flap in anterior fossa CSF leaks.

We report the clinical use of galea frontalis myofascial flaps in the treatment of anterior fossa cerebrospinal fluid leaks after trauma. This flap provides an adequately sized and vascularised barrier between the cranial and nasal cavities through which the cells of the inflammatory response reach the target area. This technique was used in 9 cases with complete success; in 5 out of 9 patients, repair of an anterior cranial base bone defect was also performed with split calvarial bone grafts, harvested from the frontal craniotomy bone. In all patients, neither recurrence of the CSF leakage nor postoperative meningitis or its recurrence were observed.

Adult↗

Effect of a short-term captopril treatment on serum and tissue angiotensin I-converting enzyme activity from four mammalian species. Differences using diamide in the in vitro assay.

1. Angiotensin I-converting enzyme (ACE) activity was determined in serum and nine tissues from control and captopril-treated rats, mice, guinea pigs and rabbits. 2. ACE activity was determined with and without sample pretreatment with diamide (total and basal activity, respectively). 3. A very different pattern of response to captopril was observed among the different species. 4. There was no relationship between serum ACE activity and the response to captopril. 5. There were important differences in the determinations of total or basal ACE activities. 6. Endogenous ACE inhibitors were found in some tissues from mouse and rabbit.

Animals↗

Effect of chloride and diamide on serum angiotensin I-converting enzyme activity from eight mammalian species.

1. The effect of chloride on serum angiotensin I-converting enzyme (ACE) activity was characterized in eight mammalian species: dog, guinea pig, hamster, human, mouse, rabbit, rat, and sheep. 2. Optimum chloride concentrations varied from 300 mM for rabbit to 1700 mM for hamster. 3. The increments with these optimum concentrations with respect to 100 mM chloride concentration were from 1.4-fold in rabbit to 7.9-fold in hamster and dog. 4. There was no correlation between serum chloride concentration or serum ACE activity and optimum chloride concentration. 5. Serum ACE increased only in humans with diamide pretreatment suggesting the presence of endogenous inhibitors.

Animals↗

Circulating levels of active, total and inactive renin (prorenin), angiotensin I and angiotensinogen in carbon tetrachloride-treated rats.

1. Plasma renin activity (PRA), plasma angiotensin I concentration (ANG I), plasma angiotensinogen concentration (PAC) and the plasma levels of active, total and inactive renin (prorenin) were measured in rats with carbon tetrachloride (CCl4)-induced acute renal failure. Rats were treated with a single oral dose of CCl4 (2.5 mL/kg) and killed 1, 2, 3 and 7 days later. 2. On days 1-3 PRA, ANG I and PAC decreased and increased on day 7. Active renin fell on days 2 and 3, total renin (trypsin treatment) augmented on day 1 and diminished on day 3, prorenin and per cent prorenin increased on days 1 and 2. Angiotensin I concentration paralleled PRA and PAC. The CCl4-induced decrease in PRA was secondary to the fall in active renin and in PAC. Total renin augmented as a consequence of the elevation of prorenin. Renal function, evaluated by serum urea, serum creatinine and creatinine clearance, decreased on days 1 and 2 when PRA was low and plasma prorenin was high. 3. These data do not support the involvement of the circulating active renin-angiotensin system (RAS) in the pathophysiology of acute renal failure induced by CCl4, however, increased prorenin levels were associated with the decrease in renal function.

Acute Kidney Injury↗

Electrophoretic analysis of serum and urinary proteins in rats with aminonucleoside-induced nephrotic syndrome.

Albumin; and alpha 1-, alpha 2-, beta-, and gamma-globulins were estimated by cellulose acetate electrophoresis in the serum and urine from rats with nephrotic syndrome (NS), 2, 4, 6, 8, 10, 12, 16, 20, and 30 days after a single injection of puromycin aminonucleoside (PAN). It was found that: (a) total serum protein level decreased on days 4-16, and total urine protein excretion rose on days 6-16; (b) serum albumin level fell on days 4-16, and urine albumin excretion increased on days 6-16; (c) serum alpha 1-globulin level rose on days 8-30, and urine alpha 1-globulin excretion increased on days 8-16; (d) serum alpha 2-globulin level remained essentially unchanged, and urine alpha 2-globulin excretion rose on days 4-10; (e) serum beta-globulin level decreased on days 4-20, and urine beta-globulin excretion increased on days 6-16, (f) serum gamma-globulin level diminished on days 6, 8, and 12, and urine gamma-globulin excretion rose on days 6-10. All serum protein fractions were excreted in the urine of nephrotic rats; these findings suggest that proteinuria is nonselective. The differences observed in the serum protein profiles, even when all protein fractions were lost in the urine, suggest an independent regulation of each protein fraction in PAN-nephrotic rats. In addition, the electrophoretic profile of serum proteins in PAN-nephrotic rats is different from previously reported patterns in human nephrosis and in rats with an acute-phase response.

Animals↗

Angiotensin I-converting enzyme activity in rats with carbon tetrachloride-induced acute renal failure.

The angiotensin I-converting enzyme (ACE) activity was measured in urine, serum, and tissues from rats with carbon tetrachloride (CCl4)-induced acute renal failure on days 1, 2, 3, and 7 after CCl4 administration. Serum ACE increased on days 1 to 3. Heart, lung, small intestine, brain, and testis ACE decreased, whereas kidney and liver ACE remained unchanged. Urine ACE activity increased from day 1 to day 3. Our data suggest that the increase in serum ACE may be secondary to the ACE release from the damaged tissues, and that the urine ACE increase may be due to the kidney proximal tubule damage. This work supports the contention that an increase in urine ACE may be an indicator of damage to the proximal tubule.

Acute Kidney Injury↗

[Medical equipment companies and their ties with technology development centers in Mexico].

The purpose of this study was to determine the characteristics of the companies that produce, distribute, and service medical equipment in Mexico and the factors related to whether or not they had established ties with research and technology development centers. The data analyzed came from a survey of such companies carried out in Mexico City and environs in 1989. The information was updated in 1991. Multivariate analyses were carried out in order to identify the characteristics of companies that had established ties or wished to do so and the areas of interest of those companies. Of 208 companies surveyed, only 23% had ties with research centers. The companies that had such ties or were interested in establishing them tended to invest in research and to have made plans for expansion. The establishment of ties appeared to be a two-way process, with positive consequences for the companies involved, the research centers, and the health sector. It was concluded that it would be advantageous to design programs to promote ties with companies having the characteristics mentioned.

Equipment and Supplies↗

Indirect measures of total body water may confound precise assessment of peritoneal dialysis adequacy.

Urea kinetic modeling (UKM) has yet to be optimized as a practical tool for assessing adequacy of therapy in continuous ambulatory peritoneal dialysis (CAPD) patients. Watson equation (WV) and 58% body weight (58%WT) estimates of total body water (TBW) are indirect measures likely to yield imprecise estimates of Kt/V. Bioelectrical impedance (BEI) measures body composition as a function of electrical conductance, minimizing fat contribution to TBW. TBW values were highest when measured as 58% WT and lowest when calculated from WV. These differences were most striking in patients with overweight body habitus. BEI-derived TBW correlated best with UKM values. The relationship between BEI-derived and anthropometrically derived TBW was best in patients of normal habitus. Kt/V values were highest when calculated from WV-derived volumes and significantly differed from Kt/V values calculated from BEI-derived and 58%WT volumes. When segregated by habitus, however, only in overweight patients was this pattern of clinical significance. Serial body weight, lean body mass, and TBW remained stable in patients of normal habitus. Overweight patients increased weight by 5%, lean mass by 2%, and TBW by 5%, 3%, and 2% when measured by 58%WT, WV, and BEI respectively. BEI measures of TBW exclude fat mass and thus strengthen the use of Kt/V for assessing dialysis adequacy in CAPD patients of all body weights.

Adult↗