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Biomedical subjects

C Cruz

Publications and source records attributed to C Cruz.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Single-pass continuous flow peritoneal dialysis using two catheters.

With a renewed interest in continuous flow peritoneal dialysis (CFPD), our standard practice of implanting a second catheter in those patients facing access failure provided us the opportunity to perform acute studies on CFPD in these patients, since it temporarily provided us with two catheters. Four patients were studied, with a total of five studies performed. A standard protocol was followed utilizing 1.5% dextrose solution, a 2 L fill, an inflow rate of 200 ml/min with a proportionate outflow for a 4-hour session. A full drain was performed at the end of the study. Our results provided us with a mean effective peritoneal clearance for urea (KpeU) and creatinine (KpeCr) of 40 ml/min and 28 ml/min, respectively, and a mean ultrafiltration rate (Qf) of 13.4 ml/min. Our average mass transfer coefficient (MTC) for urea was 40 ml/min, consistent with kinetic modeling and historical data. The Kpe, MTC, and Qf achieved are significantly higher than other investigators, which could possibly be explained by those obtained by two separate catheters resulting in adequate mixing of the dialysate. These clinical results provide a solid foundation for the future development of this PD modality.

Catheterization↗
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Training military medics as civilian prehospital care providers in Southern Sudan.

OBJECTIVE: To describe and evaluate a training program to teach civilian prehospital care to military medics in the Sudan People's Liberation Army (SPLA). METHODS: Forty-one SPLA military personnel with variable prior medical experience participated in the course. Pre- and postintervention tests were used to evaluate participant knowledge and skill level, and test results were compared using paired t-tests. RESULTS: An intensive 40-hour course consisting of didactic teaching sessions, small-group discussions, and practical skill stations was completed during November 1997. Thirty-seven participants successfully completed the program. Four medics with significant prior experience were trained as teaching assistants. The pretest scores for the other 33 participants ranged from 25.0% to 75.0% (SD 12.4). The posttest scores ranged from 25.0% to 87.5% (SD 15.2), with a mean improvement in test scores of 35.0% (p < 0.0005). The most striking improvements were noted in the knowledge of subjects related to wound care, hemorrhage, and head trauma. CONCLUSIONS: A field medic training program in Southern Sudan was conducted utilizing an interactive training curriculum. This program may serve as an educational model to teach prehospital care principles in other areas of international conflict.

Emergency Medical Technicians↗
PubMedDate not supplied

Ascites fluid of nephrotic rats: sodium dodecyl sulphate-polyacrylamide gel electrophoresis protein pattern and the renin-angiotensin system.

1. The concentration of renin and angiotensinogen (Ao) and the activity of angiotensin I-converting enzyme (ACE) was measured in the ascites fluid of nephrotic rats obtained 8 days after puromycin aminonucleoside (PAN) injection. 2. Ascites fluid, serum and urine proteins of these rats were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). 3. Renin, Ao and ACE were found in the ascites fluid and the percentage of the ratio ascites fluid/(plasma or serum) ranged from 5.9 to 9.9%. The electrophoretic analysis revealed that the ascites fluid contained low (Mr < 66 kDa) and high (Mr < 66 kDa) molecular weight proteins. Albumin and six proteins higher than 66 kDa were present both in the ascites fluid and in serum from nephrotic rats. 4. Data from the study suggest that some proteins in the ascites fluid, including renin, Ao and ACE, come from the plasma. It is possible that the loss of renin, Ao and ACE to the ascites fluid may be playing a role in the metabolic alterations of these three proteins in PAN-nephrotic rats.

Angiotensinogen↗
PubMedDate not supplied

[The "package" and nursing (critical analysis of a death scene)].

This is a descriptive study based upon an experience related by a group of nursing students in their senior year at a public university in the city of Rio de Janeiro. As part of a course content in Methodological Perspectives in Nursing II, based on problem solving, the authors analysed a death scene which occurred during practical training, in a large public general hospital, in order to describe how nursing staff deal with such an event. The main goal of the study was to provide thought provoking material from different points of view--cultural, religious and ethical--concerning the subject of death and the professional nursing ethics code. The authors concluded that the such a theme must be discussed in the academic environment, but not only from a technical point of view, for the process of human interaction which is established during health assistance demands the provision of nursing care to the patient during his entire lifespan, of which death is the last stage.

Attitude to Death↗
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Role of angiotensin II in the antinatriuresis that follows acute volume depletion.

The aim of this study was to examine the contribution of the renin angiotensin system to the antinatriuresis that follows acute volume depletion. Four groups of six dogs each were studied. The first group was exposed to saline expansion (8% body weight) (SE). The second group was exposed to acute volume depletion (2% body weight) followed in one hour by saline expansion (AVD). The third and fourth groups were similar but in dogs treated with high doses of captopril (SE + C and AVD + C). Dogs were anesthetized with phenobarbital. Control measurements were made for 30 minutes before and 60 minutes during saline expansion. Glomerular filtration rate (inulin), renal blood flow (para-aminohippuric acid) and mean arterial pressure were similar in the four groups during the experiment. The increase in fractional sodium excretion from the control period to the end of saline expansion was in the SE group from 0.6 +/- 0.2 to 6.4 +/- 1% and in the SE + C group from 1.1 +/- 0.3 to 8.5 +/- 1.3%. In contrast, in the AVD group it only rose from 0.8 +/- 0.2 to 3.5 +/- 0.7% and in the AVD + C group from 1.3 +/- 0.4 to 4.1 +/- 0.6%. Therefore, the increment in sodium excretion during saline expansion was significantly lower in dogs exposed to acute volume depletion, independent of the treatment with captopril. The blunted natriuresis cannot be explained by differences in GFR, RBF or MAP. These results suggest that renin angiotensin system is not the responsible agent of the sodium retention that follows acute volume depletion.

Acute Disease↗
PubMedDate not supplied

[Supply of medical equipment in Mexico].

This article covers the report on Supply of Medical Equipment in Mexico, presented during the Second National Congress of Public Health. The results are part of an investigation that dealt with the general conditions that currently prevail in the production and distribution of medical equipment. The information was obtained by means of a survey applied to 208 companies that comprised the sample study. The facts indicate that of the companies that correspond to this industrial sector in Mexico, 3.8 per cent are manufacturers, 69.7 per cent distributors, 19.2 per cent manufacturer-distributors, and the remaining 7.2 per cent correspond to corrective and preventive maintenance. Also, these companies pose serious problems of external dependence with regard to production costs and the commercialization of products. Furthermore, it became evident that there is a substantial need for financial support to optimally satisfy the demands of various institutions in the country's health sector.

Equipment and Supplies↗
PubMedDate not supplied

[Investigation in medical technology: support for cooperation among countries].

This paper discusses the results of the research work on medical technology in several countries by research teams whose goals are to prompt the exchange of information and support practical cooperation. Emphasis is placed on the work developed by the Pan American Health Organization, which has supported 45 research proposals on medical technology and stimulated the association of academic groups, national institutions and international agencies. The authors also describe the research activities of the team devoted to medical technology research at the National Institute of Public Health in Mexico.

Health Promotion↗
PubMedDate not supplied

[Manifestations of paralytic ileus in infants hospitalized for acute diarrheal syndrome].

In order to assess and characterize adynamic ileus (AI) complicating acute diarrhoea (AD) in infants, 802 consecutive admissions were studied. Diagnosis was suspected in 23 patients with abdominal distension and confirmed by radiological study in 16 whose age range was 14 ds to 6 mo. Of these late patients, 9/16 were malnourished. Age was less than, but nutritional status similar to that of all patients admitted with ADD. Vomiting (14/16), silent or almost silent abdomen (10/16), protracted course of diarrhoea (9/16) and increased gastric content (6/16) were the most common clinical findings in addition to abdominal distension and X Ray films suggestive of AI (inclusion criteria). Lack of constipation was a relevant finding. Treatment included temporal discontinuance of oral feedings, intravenous fluids administration, nasogastric and rectal tube and antibiotics. Lethality rate was 4/16. Duration of AI was an average of 2 days in survivors and 4 days in the remainder infants. It is concluded that AI is an infrequent complication of AD (0.19% of cases), which should be suspected in infants less that 6 mo old with diarrhoea and abdominal distension.

Acute Disease↗
PubMedDate not supplied

Pathophysiology of experimental nephrotic syndrome induced by puromycin aminonucleoside in rats. I. The role of proteinuria, hypoproteinemia, and renin-angiotensin-aldosterone system on sodium retention.

The pathophysiology of the nephrotic syndrome (NS), characterized by protenuria, edema, sodium retention and hyperlipidemia, is not clear. We studied the role of some systemic factors on sodium retention in an experimental model of NS. NS was induced in rats by a single subcutaneous injection of puromycin aminonucleoside (PA) (15 mg/100 g); control animals received vehicle. All rats were kept in metabolic cages for 24 days (3 days before and 21 days after PA-injection). Urine was collected daily. Blood samples were obtained every day until day 10, and then every other day up to the end of the study. The rats showed the following alterations after PA injection: a) a rise in serum angiotensin converting enzyme activity (ACEA) and plasma aldosterone (PAldo) at day 1; b) a rise in urinary aldosterone (UAaldoV), azotemia and sodium retention at day 2; c) massive proteinuria (UProt) and decrease in plasma angiotensinogen concentration (PAC) at day 4; d) increases in plasma renin activity (PRA), plasma renin concentration (PRC) and serum creatinine as well as hypoproteinemia, hypercholesterolemia, hypertriglyceridemia, ascitis and edema at day 5; e) increase in urine volume at day 6. PAldo became normal at day 7; urine sodium (UNaV), PRA and PRC at day 8; UAldoV at day 9; serum urea and ACEA at day 10; urinary volume at day 11; PAC, serum total protein and creatinine at day 12. The edema disappeared at day 11. UProt, hypercholesterolemia and hypertriglyceridemia persisted, though they decreased substantially by the end of the study (day 21). Light microscopy studies revealed normal glomerular morphology, but electron microscopy showed fusion of podocytes before proteinuria. These data suggest that: a) sodium retention was not a consequence of proteinuria or hypoproteinemia; b) sodium retention seems non-related to renin secretion, but may be partially mediated by a fall in glomerular filtration rate or by an increased tubular resabsorption secondary to other factors; c) the increase in PAldo, UAldoV and ACEA are non-related to renin secretion: all occurred before PRA rose; d) water retention, increase in PRA and PRC, hypercholesterolemia and hypertriglyceridemia are secondary to the hypoproteinemia.

Animals↗
PubMedDate not supplied

Pathophysiology of experimental nephrotic syndrome induced by puromycin aminonucleoside in rats. II. In vitro release of renin, angiotensinogen and aldosterone.

In vitro release of renin, angiotensinogen and aldosterone was studied in control (CT) and nephrotic rats. Nephrotic syndrome (NS) was induced by a single injection of puromycin aminonucleoside (PA). The in vitro systems used were: renal cortical slices (RCS), liver slices (LS) and adrenal glands, all incubated in Krebs-Ringer buffer. Renal renin content (RRC) and isoproterenol-induced renin secretion (RS) also were studied. RS, RRC and angiotensinogen release were measured indirectly by radioimmunoassay (RIA) of angiotensin I (ANG I); aldosterone was estimated by direct RIA. Basal RS was not modified in NS: 385 +/- 196 (CT) vs 344 +/- 149 ng ANG I/mg protein/h (NS), p greater than 0.05. Isoproterenol increased RS significantly in both CT and NS groups: 535 +/- (CT) and 685 +/- 231 ng ANG I/mg protein/h (NS) (p less than 0.05 vs. basal RS). RRC was similar in both groups: 2.17 +/- 0.62 (CT) vs 2.05 +/- 0.49 micrograms ANG I/mg protein/h (NS), p greater than 0.05. Angiotensinogen release from LS increased in nephrotic rats from 10 +/- 3.2 (CT) to 12 +/- 1.9 pmoles angiotensinogen I/mg tissue/2h (NS), p less than 0.05. Aldosterone release increased markedly from adrenal glands of rats with NS (1649 +/- 1111 pg aldosterone/mg tissue/h) with respect to control rats (257 +/- 85), p less than 0.05 In vitro studies were performed six days after PA-injection, when nephrotic rats had ascitis, edema, proteinuria, hypoproteinemia, hypercholesterolemia, hypertriglyceridemia, low sodium and aldosterone excretion, low levels of plasma angiotensinogen and high levels of plasma renin and aldosterone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMedDate not supplied

Pathophysiology of experimental nephrotic syndrome induced by puromicyn aminonucleoside in rats. III. Effect of captopril, an angiotensin converting enzyme inhibitor, on proteinuria and sodium retention.

The effect of the converting enzyme inhibitor (CEI) (captopril, 50 mg/kg/day) on proteinuria (UProt), urinary aldosterone (UAldoV), plasma renin activity (PRA), plasma renin concentration (PRC), plasma angiotensinogen concentration (PAC), urinary sodium (UNaV), serum total protein, and body weight was studied for 21 days in an experimental nephrotic syndrome (NS) model induced in rats by a single injection (15 mg/100g) of puromycin aminonucleoside (PA). The effect of captopril on control rats without NS was also characterized. In control rats, captopril increased PRC and PRA, and decreased PAC; it had no effect on UNaV, UAldoV, UProt, total serum protein and body weight. In rats with NS, captopril had no effect on sodium retention, hypoproteinemia, and UProt; it abolished the increased UaldoV and favored weight loss. Captopril also rose PRA and PRC, and decreased PAC in PA-nephrotic rats; these changes were similar to those produced by captopril in control rats. The mortality rate was higher in nephrotic rats treated with captopril (37%) than in untreated nephrotic rats (13%). It is concluded that captopril has no beneficial effects on the course on NS induced by PA during the first 21 days, and supports the contention that sodium retention is not related to the renin-angiotensin-aldosterone system activity in these rats.

Animals↗
PubMedDate not supplied

Non-productive or thalassemic-like heavy-chain gene rearrangement in a K-chain CLL clone.

Information obtained from the study of immunoglobulin (Ig) gene rearrangement in different types of lymphoproliferative disorders has led to the suggestion that Ig gene activation obeys a precise hierarchy in which heavy-chain gene rearrangement procedes light-chain gene recombination. However no information is available on the mechanism(s) controlling this sequential activation. We report here a case of CLL which suggests that the expression of the heavy-chain genes is not necessary for light-chain gene rearrangement, or that very low amounts of heavy-chain mRNA and/or heavy chains are sufficient to activate k-chain genes.

Aged↗
PubMedDate not supplied

[Intracellular messengers in the regulation of renin secretion].

The intracellular messengers that seem to be involved in renin secretion (RS) from juxtaglomerular cells (JG) are calcium (Ca), cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Unlike the majority of secretory systems, an increase in intracellular Ca concentration and calmodulin and protein kinase C activation inhibit RS. The intracellular Ca concentration in JG cells can be modified if: 1) the normal mechanisms of Ca extrusion of these cells is altered; 2) the calcium output is blocked by lanthanum; 3) the function of the voltage-sensitive Ca-channels is modified; 4) uptake or liberation of Ca from endoplasmic reticulum is modified; 5) plasmatic membrane is bypassed with calcium ionophores such as A 23187. 6) JG cells are stimulated by hormones that increase Ca and activate protein kinase C such as angiotensin II, vasopressin or alpha-1 adrenergic agonists; 7) extracellular Ca concentration increases or decreases. RS is stimulated by dibutyryl cAMP, cAMP phosphodiesterase inhibitors and by hormones and agents that activate adenylate cyclase (beta adrenergic agonists, bradykinin, histamine, forskolin and ethylcarboxamide adenosine). On the contrary, RS is inhibited by hormones and agents that inhibit adenylate cyclase such as: alpha-2 adrenergic agonists, neuropeptide Y, angiotensin II and cyclohexyladenosine. Pertussis toxin increases basal RS, blocks the inhibition by agents and hormones which inhibit adenylate cyclase and potentiate the stimulation produced by beta-adrenergic agonists. In JG cells, atrial natriuretic peptide inhibits RS, increases cGMP and decreases cAMP. The increase in cGMP correlates well with the inhibition of RS.

Calcium↗
PubMedDate not supplied

The peritoneoscopic implantation of a polyurethane percutaneous access device for peritoneal dialysis. Preliminary experience.

The short-term experience with peritoneoscopic implantation of eight Dermaport devices is discussed. These eight devices were implanted using local anesthesia and utilizing a modification of the Y-TEC method of catheter implantation. Excellent immediate function was observed universally allowing catheter use for dialysis and good skin-device interface; however dialysate leakage occurred within 2 to 4 weeks in four patients. Lack of permanent bonding between the catheter and the adjustable proximal cuff, resulting in suboptimal or slow ingrowth of tissue around it, appears to be the cause of this phenomenon.

Adult↗