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Biomedical subjects

M Ballesteros

Publications and source records attributed to M Ballesteros.

48 records · Page 3Linked to original sources
PubMed1991

Influence of hypertonic volume replacement on the microcirculation in cardiac surgery.

We have studied the effects of two types of volume replacement on the microcirculation in an open, controlled study in 45 patients undergoing aorto-coronary bypass grafting whose pulmonary capillary wedge pressure (PCWP) was less than 5 mm Hg. Hypertonic saline prepared in hydroxyethylstarch solution (HS-HES, n = 15) and 6% HES 200/0.5 solution (6% HES; n = 15) were infused randomly before operation in order to double the PCWP. Patients not given an infusion served as controls (n = 15). Skin microcirculatory blood flow was investigated by laser Doppler flow (LDF) measured simultaneously at the forearm and forehead before and after cardiopulmonary bypass (CPB). Less HS-HES (3.8 (SD 0.3) ml kg-1) than 6% HES-solution (9.7 (1.5) ml kg-1) was necessary to double baseline PCWP. There were no differences in heart rate and mean arterial pressure (MAP) between the groups. Cardiac index (CI) increased significantly in both volume groups (HS-HES max. +54%; 6% HES max. +30%). Systemic vascular resistance (SVR) decreased after infusion of HS-HES (-30%) and after 6% HES(-19%) and remained almost unchanged in the control group. Plasma viscosity decreased after infusion of HS-HES and increased slightly in control patients (+4%). In comparison with the 6% HES and particularly with the control group, LDF was significantly greater after infusion of HS-HES (forearm +80%; forehead +28%). LDF during CPB and thereafter was always greater than baseline values in the HS-HES group, whereas after bypass LDF was reduced in the 6% HES (-5%) and particularly in the control patients (-30%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Developmental regulation of insulin-like growth factor-II/mannose 6-phosphate receptor mRNA in the rat.

This study examined levels of insulin-like growth factor-II/mannose 6-phosphate receptor (IGF-II/M6PR) mRNA in tissues of rats at different stages of growth. Northern blot analysis of total RNA from tissues of rats aged 2, 9, 21 and 42 days and from 21 day fetal rats was carried out using a cDNA probe to the IGF-II/M6PR. Northern blots showed this probe hybridized to a single 9kb band in all tissues tested. Highest hybridization signals were detected in fetal and neonatal tissues with levels rapidly decreasing after birth. For all age groups tested the highest signal was obtained with heart followed by muscle, lung, and kidney, with liver and brain showing lower levels of message. These results indicate that IGF-II/M6PR mRNA is developmentally regulated, and suggest a role for the IGF-II/M6PR in fetal and neonatal growth.

Aging↗
PubMed1990

Increased expression of insulin-like growth factor-II/mannose-6-phosphate receptor in regenerating rat liver.

This study examined the effect of two thirds hepatectomy on rat liver insulin-like growth factor-II (IGF-II) receptors and IGF-II receptor messenger RNA (mRNA) levels. IGF-II receptor levels were determined in liver plasma membrane and Golgi/endosome fractions from sham-operated and hepatectomized rats by ligand binding and immunoblotting after electrophoresis. After hepatectomy, IGF-II receptors increased initially in the plasma membrane (within 24 h of surgery) to 4-fold control levels, remained elevated for 72 h, and declined to control levels at 120 h when liver regeneration is near complete. However, Golgi/endosome levels of IGF-II receptors did not increase until 48 h, showing a maximum increase of 3.5-fold at 72 h after surgery and returning to control values at 120 h. The 9-kilobase mRNA for IGF-II receptor, determined by slot blotting with a complementary DNA probe, increased 2.5-fold within 24 h of surgery, attaining a maximum stimulation of 4-fold at 48 h, and then decreasing to normal levels by 120 h. These changes show that, after partial hepatectomy, IGF-II receptors increase rapidly at the cell surface, possibly due to receptor translocation from intracellular pools. This is followed by an increase of IGF-II receptor mRNA and increased receptor synthesis, resulting in an increase in total cellular receptors. These results suggest a role for IGF-II receptors in regenerating liver, perhaps in cell proliferation and/or in tissue remodeling.

Animals↗
PubMed1985

Respiration rate, growth rate and the accumulation of streptomycin in Escherichia coli.

Using chemostat cultures of Escherichia coli it was possible to vary respiration rates while maintaining a constant growth rate. This allowed the effect of variations in respiration rates on the accumulation of streptomycin to be studied in cultures at constant growth rates. At a particular dilution rate cultures exhibited higher respiration rates when phosphate limited growth than when carbon limited growth. A ubiquinone-deficient strain had a lower rate of respiration at a particular dilution rate than a related ubiquinone-sufficient strain. In spite of these differences in respiratory activity, the accumulation of streptomycin was identical in carbon- and in phosphate-limited chemostat cultures of ubiquinone-deficient and ubiquinone-sufficient strains. Moreover, accumulation of streptomycin in an anaerobic chemostat culture occurred at the same rate as that in an aerobic chemostat. There was however a lag of 1.5 h before accumulation commenced in the anaerobic culture, a feature that was not apparent in the aerobic culture. These results indicate that the lower rates of respiration in slow-growing bacteria are not responsible for the decreased accumulation of streptomycin in slow-growing compared to fast-growing cultures. Moreover, it seems unlikely that quinones are involved directly (e.g. as carriers) in streptomycin accumulation, since removal of 90% of cellular ubiquinone, or replacement of ubiquinone with a structural analogue, did not affect accumulation as long as mutant and parent cultures grew at the same rate.

Anaerobiosis↗
PubMedDate not supplied

Dipeptidyl peptidase IV is down-regulated in rat hepatoma cells at the mRNA level.

Dipeptidyl peptidase IV (DPP-IV) is a cell surface ectopeptidase that has been implicated in cell-extracellular matrix interactions, lymphocyte growth and the regulation of biological peptides. Previous studies have shown that immunostaining for DPP-IV and DPP-IV enzyme levels is decreased in hepatoma cells and levels have been correlated with the ability of such cells to adhere in vitro. The aim of this paper was to measure DPP-IV enzyme levels in rat hepatoma cells and to examine whether changes were associated with alterations at the mRNA level. The results indicate a greater than 90% reduction in DPP-IV enzyme levels in two rat hepatoma cell lines, HTC and H35, compared with rat hepatocytes. Enzyme levels of the control enzyme leucine aminopeptidase (LAP) were not decreased. mRNA studies indicated that these changes were associated with similar reductions in rat DPP-IV mRNA. It is concluded that DPP-IV is markedly reduced at the protein, enzyme and mRNA levels in rat hepatoma cells. The significance of these changes is unclear but may lead to decreased extracellular matrix interactions by such cells.

Animals↗
PubMedDate not supplied

Factors associated with attendance in a voluntary nutrition education program.

PURPOSE: This paper examines factors associated with attendance in a National Cancer Institute-funded randomized trial of nutrition education to increase fruit and vegetable consumption among women served by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). SETTING: The study took place at 16 WIC sites in Maryland. SUBJECTS: The participants were 1528 women who were enrolled in WIC or who had children enrolled in WIC, were > or = 18 years of age, and planned to continue enrollment at that WIC site for at least 6 months (68% of eligible women approached agreed to participate). INTERVENTION: Women received personal invitations, letters, and telephone reminders from peer educators encouraging their attendance at three bimonthly nutrition sessions. MEASURES: Demographic data were collected in a baseline survey. Attendance data and telephone and address changes were also collected. The postintervention survey included a question regarding reasons for nonattendance. Focus groups were also held to ascertain reasons for attendance or nonattendance. Chi-square tests of trend and multiple logistic regression, adjusted for within-site correlation, were used in statistical analyses. RESULTS: Fifty-four percent of enrollees attended at least one session. Multiple logistic regression analysis showed increased odds of attending with higher age, breast-feeding, and/or knowledge of the recommendation to eat five or more servings of fruits and vegetables daily. There were decreased odds of attending for pregnant women who already had children. There were nonsignificant trends toward decreased attendance among unmarried women compared with married women and among blacks compared with nonblacks. Reasons given for nonattendance included withdrawal from WIC, moving, conflicting activities, negative feelings about nutrition education, and lack of transportation or child care. CONCLUSIONS: The results suggest that numerous barriers hinder participation in nutrition programs aimed at low-income women. These barriers should be considered by health care professionals when planning intervention programs. Overcoming these barriers presents a major challenge.

Adolescent↗
PubMedDate not supplied

[Current status of clinical nutrition at the network of public hospitals from Castilla y León].

INTRODUCTION: Clinical nutrition is an activity realized in most of Health Centres of France, Canada, Great Britain and USA. The aim of our work was to determine activity and resources of Nutrition Units of Hospitals in the Community of Castilla y León. MATERIAL AND METHODS: A questionnaire was send to all Hospitals of Castilla y León (SACYL); Hospital Universitario Rio Hortega, Hospital Clinico Universitario, Hospital Comarcal de Medina del Campo, Hospital General Yagüe-Divino Vallés (Burgos), Complejo Hospitalario de Le6n, Hospital General de Segovia, Hospital Virgen de Sonsoles de Avila, Hospital Virgen de la Concha de Zamora, Hospital Comarcal de Aranda de Duero, Hospital Comarcal de Miranda, Hospital General de Soria, Hospital Clinico Universitario de Salamanca. RESULTS: Nine Centres responded questionnaire (75%). A total of 5 Hospitals had a Unit of Nutrition (55.6%). The results showed an average of 0.37 +/- 0.55 specialists for each 400 beds, 0.87 +/- 0.63 nurses for each 400 beds and 1.91 +/- 2.3 auxiliaries for each 400 beds, with an average of 0.21 +/- 0.41 specialists for each 100,000 habitants, 0.49 +/- 0.36 nurses for each 100,000 habitants and 1.09 +/- 1.2 auxiliaries for each 100,000 habitants. The activity of these Units is demanded by other Units, with an average of 3.2 +/- 3.4 consultations per day. The main diseases of this activity were 33.3% tumoral pathology, 55.6% surgery and 11.1% neurological pathology. Oral supplements were the first intervention tool. Only 3 Centres had a home artificial nutrition consultation. The main diseases of this activity were post surgical patients (33,3%), tumoral pathology (33,3%), neurological pathology (22%) and inflammatory bowel disease (11%). CONCLUSION: Resources in Units of Nutrition of Castilla y Leon were limited. However, activity in Hospital an in home is equal than other areas. New actions of Local Administration are necessaries to follow recommendations of Council of Europe.

Hospital Units↗
PubMedDate not supplied

[The usefulness of serum creatinine levels in identifying hospital malnutrition].

PURPOSE: to determine the diagnostic accuracy of seric creatinine in the depletion of the somatic compartment and in adult malnutrition. DESIGN: a prospective study. PLACE: a tertiary care centre. PATIENTS: 140 subjects evaluated by the nutritional support group. EXCLUSION CRITERIA: kidney insufficiency, immune-suppression, malignant illness, sepsis and multisystemic organ failure. PROCEDURES: appraisal of the somatic compartment (weight deficiency percentage, arm muscle circumference, cutaneous triceps fold an twenty-four hour creatinuria) and the visceral compartment (series albumin and lymphocyte count). Calculation of derived variables. MAIN RESULTS: 74% of patients had creatinine levels of 0.8 mg% or less and, of them, 79% were malnourished. The diagnostic acuteness of seric creatinine levels of this limit or lower is 73% for somatic compartment deficiency, and 75% for some degree of malnutrition. There is a significant negative correlation between the absolute value of the cutaneous triceps fold and seric creatinine levels. CONCLUSIONS: seric creatinine levels of 0.8 mg% in hospitalized patients suggest a somatic deficiency. The presence of this parameter within these limits makes it highly advisable to carry out a complete nutritional evaluation. However, these values should not be considered an irrefutable indicator of adult malnutrition. Seric creatinine levels analyzed together with the tricipital cutaneous fold values serve to identify depletion of the somatic compartment to the greater detriment of the fat component than the muscular component.

Adult↗