Biomedical subjects

J M Ruiz

Publications and source records attributed to J M Ruiz.

At least 37 records · Page 2Linked to original sources

PubMed1998

[Ambulatory blood pressure monitoring in the aged. The EPICARDIAN study. The EPICARDIAN Work Group].

OBJECTIVE: To determine reference values for ambulatory blood pressure in a random sample of Spanish elderly population, and their correlations with office blood pressure measurements. METHODS: A representative random sample was obtained, stratified by sex and age, of 1,227 elderly subjects aged > 65 years, residents in an urban district, Barrio de Salamanca, or Madrid, Spain. In a random subsample (n = 420), two different blood pressure measurement approaches were performed: Office blood pressure and twenty-four hour ambulatory blood pressure (spacelabs 90207) were recorded, and two periods were defined: awake and sleeping, on the basis of the daily activities. Hypertension was defined if the average of casual blood pressure was > or = 140/90 mmHg or if there was current use of antihypertensive drugs. RESULTS: Among the 420 participants, 333 ambulatory blood pressure monitorings were performed, 301 with valid registers, of whom 105 were receiving antihypertensive drug treatment. Office, 24 hour, awake and sleeping pressures averaged 147/84 mmHg, 128/72 mmHg, 132/77 mmHg and 122/66 mmHg respectively. Differences between whole sample and no treated group were not significant (p = 0.2), nor between the whole sample and the treated group (p = 0.7). Office blood pressure was markedly higher than 24 hour and awake averages (20 and 15 mmHg for systolic and 12 and 7 mmHg for diastolic, respectively). The differences between clinic and awake average blood pressures were significantly higher in females (p = 0.001) and increased, in both genders, as age (p = 0.001) and clinic blood pressure values (p < 0.000) increased. Correlation coefficients between office and the average awake period of the ambulatory blood pressures were of 0.60 and 0.48 for systolic and diastolic respectively. The ambulatory blood pressure value equivalent to 140/90 mmHg when obtained by causal measurement, was 15 mmHg lower when considering the 24 h average, or 10 mmHg lower when the awake averages. CONCLUSION: Ambulatory systolic and diastolic blood pressure values in the elderly are markedly lower than office values, specially in the case of systolic blood pressure. Differences in results between the two methods increase with age and with clinic blood pressure values, and are bigger in females. The cut-off point for ambulatory blood pressure monitoring equivalent to 140/90 mmHg in the casual measurement is of 125/75 mmHg for the 24 hour average and of 130/80 mmHg for awake average.

Age Factors↗

PubMed1997

[Immunocompromised travelers].

More and more immunocompromised people travel abroad especially in tropical countries where infectious risks are high. Before leaving, these subjects must consult their general practitioner who will determine their fitness in function of type of immunodeficiency, travel destination, availability of medical care at the destination, and possibility of medical evacuation. Counseling should also be provided concerning the precautions necessary to avoid the hazards of exposure to fecal material, venereal disease, insect bites, and sun. Antimalarial drug prophylaxis is the same as for uncompromised subjects. Advising immunocompromised subjects about vaccinations is difficult since there is no consensus on the subject. Administration of inert vaccines is usually recommended but their effectiveness is often diminished and harmful effects have been observed in HIV-infected subjects. Administration of live vaccines is always contraindicated in severely immunocompromised subjects but some live vaccines can be used in moderately immunocompromised subjects. The guidelines for vaccination differ depending on the underlying cause of immunodeficiency: congenital defects, cancer, hemopathy, treatment with immunosuppressors or corticosteroids (transplant patients and patients with systemic disease), HIV-infection, or spleen dysfunction. If there is a high risk of contracting a disease for which vaccination is contraindicated, drug prophylaxis or administration of immunoglobulins can be an alternative. If not, travel should either be postponed or the destination should be changed.

Counseling↗

PubMed1996

A dose-finding study of lanreotide (a somatostatin analog) in patients with colorectal carcinoma.

BACKGROUND: Laboratory data suggest that insulin-like growth factor-1 (IGF-1) may stimulate the growth of different human tumors. At least in acromegalic patients, somatostatin (SMS) analogs, such as lanreotide, suppress the serum levels of growth hormone (GH) and IGF-1. METHODS: To evaluate the tolerability and biologic activity of different doses of lanreotide in patients with advanced colorectal carcinoma, consecutive groups of 3 patients each were subcutaneous treated with lanreotide at doses of 1, 2, 3, 4, 5, or 6 mg three times a day for 2 months. In the event of Grade 3 side effects, 3 additional patients were treated with the same dose before the next dose escalation. Serum samples were obtained on Days 0, 15, 30, and 60 for serum GH, IGF-1, and lanreotide assessment. RESULTS: Twenty-four patients were enrolled and all were evaluable. Except for the 3 and 6 mg doses, for which the observation of a Grade 3 side effect required that an additional three patients be treated, it was sufficient to treat 3 patients at each dose. The overall incidence of side effects was as follows: changes in bowel habits, 83%; abdominal cramps, 79%; diarrhea, 17%; vomiting, 17%; nausea, 21%; steatorrhea, 78%; hyperglycemia, 35%; laboratory hypothyroidism, 39%; gallstones, 13%; and weight loss, 17%. No evidence of an increase in the incidence, intensity, or duration of side effects was observed with dose escalation. Serum IGF-1 levels were as follows: Day 15: 63%, 60%, and 67% of the baseline values for the low (1-2 mg), intermediate (3-4 mg), and high (5-6 mg) dose groups, respectively; Day 30: 63%, 59%, and 51%, respectively; and Day 60: 73%, 69%, and 47%, respectively. Serum lanreotide levels declined during treatment in all of the dose groups (90 ng/mL on Day 15, and 35 ng/mL on Day 60 for the 5-6 mg group; 10 ng/mL on Day 15, and 1.5 ng/mL on Day 60 for the 1-2 mg group). No antitumor activity or tumor marker reduction was observed. CONCLUSIONS: No increase in toxicity was observed when subcutaneous lanreotide doses were escalated to 6 mg three times a day for 2 months. The highest doses seemed to maintain reduced serum IGF-1 levels; with the lowest doses, a "rebound" in serum IGF-1 levels was observed during treatment. Nevertheless, intermittent subcutaneous injections do not ensure constant serum drug concentrations over time.

Adult↗

PubMed1996

Effects of cold ischemia time on the graft after orthotopic liver transplantation. A bile cytological study.

We conducted a daily analysis of bile cellularity in 16 orthotopic liver transplant patients fitted with a T-tube, and correlated the cytological parameters (number of cells per slide, and percentage of difference cell types) with the duration of cold ischemia time (CIT). Two groups were established: one comprised patients whose CIT was less than 7 hr (CIT averaged 345 min) and the other comprised patients with a CIT of more than 7 hr (CIT averaged 505 min). The control group consisted of 15 patients who had received cholecystectomy for biliary lithiasis and were fitted with a T-tube. All 3 groups showed the highest cell density on the 1st postoperative day (control: 53.3 +/- 15.5 cells/slide; short ischemia: 70 +/0 21.4 cells/slide; long ischemia: 158.8 +/- 53.2 cells/slide), which steadily ischemia group showed a higher cell density than did the control group for the first 2 days, although this was not significant. The long ischemia group showed the highest cell density, although only significantly for the first 2 days when compared with the controls, and basically at the expense of a increase in ductal epithelial cells. Our results show that prolonged cold ischemia causes an increase in bile cell density at the expense of ductal epithelial cells: the longer the preservation time, the greater the increase.

Adolescent↗

PubMed1996

Three decades of tributyltin in the coastal environment with emphasis on Arcachon Bay, France.

This account briefly reviews the fate, bioconcentration and effects of tributyltin (TBT) three decades after its introduction into the coastal environment. Data on TBT-related events that occurred in Arcachon Bay (gastropod imposex, oyster recruitment failure, oyster shell malformations, concentrations in water and sediments) are revised and reinterpreted. Historically, TBT concentrations in the waters of the open bay seldom exceeded 1 ng Sn l(-1) in the 1960s, likely surpassed the range of 100 ng Sn l(-1) from 1977 to 1981 (years when no oyster spat were collected and the local shellfish industry collapsed), and decreased to about 1 ng Sn l(-1) in the late 1980s and early 1990s following legislation in January 1982 banning TBT use. TBT pollution is discussed in relation to the green tides that have developed in Arcachon Bay since 1982.

Journal Article↗

PubMed1995

Antioxidant therapy in the treatment of experimental acute corneal inflammation.

To ascertain the effectiveness of topical antioxidant therapy on acute corneal inflammation, we have studied the effectiveness of topical treatment with a saline solution and with antioxidants such as 0.2% superoxide dismutase and 0.5% dimethylthiourea (DMTU) in a controlled experimental study. The evolution of the inflammatory process was evaluated by a multimodel approach, including computer-assisted planimetry of the corneal ulcer and infiltrate, ultrasonic pachymetry, luminol-amplified chemiluminescence and the study of corneal transparency by direct spectral spectrophotometry transmittance. The experimental model was a corneal ulcer created by a 60-second application of 1 N sodium hydroxide. Topical treatment with DMTU was shown to significantly improve all parameters tested, while superoxide dismutase reduced only the corneal ulcers. Antioxidant topical therapy with DMTU was shown to be efficient in reducing the inflammatory reaction that occurs during acute corneal inflammation. This suggests that antioxidant therapy could be considered as a complementary treatment in the pharmacological modulation of acute corneal inflammation.

Acute Disease↗

PubMed1994

Pharmacokinetic and pharmacodynamic properties of a long-acting formulation of the new somatostatin analogue, lanreotide, in normal healthy volunteers.

1. The aims of the study were to assess the pharmacokinetic parameters and the hormonal effects of the slow-release formulation of the somatostatin analogue (SR-L) in normal male volunteers. 2. Eight healthy males were studied. For the determination of basal values blood was sampled before the injection of vehicle and then every other hour for 8 h in order to measure plasma GH, prolactin (PRL), TSH, free thyroxin (fT4), insulin and glucagon levels. Plasma insulin-like growth factor 1 (IGF-1) levels were measured on a single sample. On day 1 of the study, 30 mg SR-L was administered intramuscularly. Blood was drawn just before injection and then every other hour for a period of 8 h. Thereafter, blood was sampled three times a week for 3 weeks in order to measure lanreotide, IGF-1, TSH, fT4 and PRL concentrations. Plasma GH was determined on days 6 and 11 of the study. 3. Plasma lanreotide concentrations rose to 38.3 +/- 4.1 ng ml-1 2 h following injection. The levels then progressively decreased, remaining above 1.5 ng ml-1 until day 11 and reaching 0.92 +/- 0.28 ng ml-1 2 weeks after injection. The apparent plasma half-life and mean residence time were 4.52 +/- 0.50 and 5.48 +/- 0.51 days respectively. 4. By comparison with the control day, plasma insulin concentrations only decreased 2 h following injection, whereas plasma glucagon did not change at any time. 5. Plasma TSH concentrations were significantly (P < 0.01) reduced from 2 h to day 4 following SR-L injection.2+ '

Abdominal Pain↗

PubMed1994

Topical treatment of experimental acute corneal inflammation by dexamethasone and nonsteroidal drugs.

In this study, we have correlated the relative effectiveness of nonsteroidal anti-inflammatory drugs versus corticosteroids in the topical treatment of acute corneal inflammation. The authors have studied the effect of 1 drop every 6 h of flurbiprofen 0.03%, indomethacin 1%, diclofenac 0.1% and dexamethasone 0.1% in an experimental model of corneal alkali burn. The objective parameters used to evaluate the corneal inflammatory response were Luminol-enhanced chemiluminescence, ultrasonic pachymetry and computer-assisted analysis of the area of the corneal ulceration. Indomethacin 1% showed statistically significant effects on the improvement of all the parameters tested in the study. No such effect was demonstrated for flurbiprofen 0.03% or diclofenac 0.1%. We can conclude that indomethacin 1% is an effective drug in the treatment of experimental acute corneal alkali-burn inflammation.

Acute Disease↗

PubMed1993

Vagal system involvement in changes in small bowel motility during restraint stress: an experimental study in the dog.

Changes in small intestinal motility were studied during restraint stress in fasting animals and after food; the involvement of the vagal system in the pathophysiology of these changes was assessed. Small intestinal motility was recorded in 40 dogs using electromyography with monopolar electrodes and manometry with submucosal microballoons. Twenty animals underwent bilateral truncal vagotomy. Stress increased intestinal motility (percentage of slow waves followed by action potentials in 1 min), both in fasting conditions (P < 0.001) and post-prandially (P < 0.001). It also completely abolished the migrating motor complex-interdigestive myoelectric complex periodicity characteristic of the normal fasting pattern. In dogs subjected to vagotomy, restraint stress increased motility during fasting (P < 0.001) but decreased it after feeding (P < 0.01). Restraint stress thus increases small intestinal motility, both during fasting and after food. The vagal system is partially involved in this hypermotility response.

Animals↗

PubMed1993

Protective properties of viscoelastic substances (sodium hyaluronate and 2% hydroxymethylcellulose) against experimental free radical damage to the corneal endothelium.

Hydrogen peroxide (H2O2) has potent oxidant properties due to the action of free radicals (OH.) induced from its degradation. The free radicals specie derived from H2O2 are extremely toxic to the corneal endothelium and quickly induce corneal edema. In the present work, in order to ascertain the endothelial cell protection from viscoelastic substances, we have studied experimental corneal endothelial cell damage caused in the rabbit eye after intracameral injection of different H2O2 concentrations, with and without previous filling and washing out of two widely used viscoelastic substances from the anterior chamber such as 1% sodium hyaluronate (Healon) and hydroxypropylmethylcellulose (HPMC). We observed a dose-dependent endothelial damage in the controls. The experimental groups protected with Healon or HPMC showed statistically fewer corneal endothelial cell lesions than the control group (p < 0.001) for all of the concentrations used. Healon showed superior protective properties than HPMC at higher H2O2 concentrations (100 mM). However, HPMC was superior with 1 and 10 mM peroxide. From this experimental evidence, we conclude that Healon and HPMC are effective as protectors against the corneal endothelial lesions caused by free radicals. This finding may explain some of the beneficial effects of these viscoelastic substances.

Animals↗

PubMed1993

Lipid peroxidation in the iris and its protection by means of viscoelastic substances (sodium hyaluronate and hydroxypropylmethylcellulose).

Free radicals, especially the hydroxyl radical (OH.), are known to be toxic for several ocular structures including the cornea, lens, iris and retina through the initiation of lipid peroxidation of cell membranes. The oxidative damage to the iris epithelial-cell membranes, induced by the injection of hydrogen peroxide (H2O2) at different concentrations into the anterior chamber of the rabbit eye, was studied by means of the measurement of lipid peroxidation products. Thiobarbituric acid reactive (TBAR) products were significantly increased compared with normal control iris after the intracameral injection of H2O2 at concentrations of 0.1 (p < 0.02), 10 and 100 mM (p < 0.001). Viscoelastic substances, widely used in anterior ocular surgery, sodium hyaluronate (Healon) and hydroxypropylmethylcellulose, show a protective effect against rabbit iris lipid peroxidation. A statistically significant (p < 0.001) inhibition of the release of TBAR products occurred in both experimental groups that received an injection of these substances prior to a H2O2 injection. This is the first report of lipid peroxidation of the iris and the 'antioxidant'-protective effect of viscoelastic substances. This new technical approach could be used as a test of efficacy of the protective effect of viscoelastic substances.

Animals↗

PubMed1993

Pharmacokinetics and efficacy of a long-acting formulation of the new somatostatin analog BIM 23014 in patients with acromegaly.

The treatment of acromegalics with somatostatin analogs requires continuous sc infusion using pumps or several sc injections daily. Long-acting formulations (BIM-LA) of BIM 23014 (BIM) using delayed microcapsules may provide a more convenient form of therapy. Fourteen acromegalics whose GH secretion had not been normalized by transphenoidal surgery followed, in 10 cases, by pituitary radiotherapy (performed at least 2 yr before the study) were studied. Eight of these patients participated in an initial study of the pharmacokinetics of BIM-LA, after which a 6-month efficacy study was undertaken. The 8 patients in the pharmacokinetic study had an initial blood sample collected for measurements of plasma GH and insulin-like growth factor-I (IGF-I) levels before the im injection of 30 mg BIM-LA, and blood samples were subsequently taken 2, 4, 6, and 8 h after injection and then twice a week for a month. Plasma IGF-I levels were measured on days 4, 14, 20, and 30 after the injection. Assays of plasma GH, IGF-I, and BIM levels were performed by RIAs. The results showed that plasma GH levels were markedly reduced from 26.0 +/- 2.0 to 2.5 +/- 0.2 micrograms/L 2 h after BIM-LA injection and remained lower than 5 micrograms/mL for the 11 following days. Plasma GH levels increased to 5.5 +/- 1.2 micrograms/L on day 14 and returned to basal values 23 days after injection. Similarly, plasma IGF-I decreased from an initial level of 656 +/- 43 to 324 +/- 23 ng/mL on day 4 and remained close to the normal range for the following 10 days. Plasma BIM levels reached a peak 2 h after the injection (7.2 +/- 2.3 ng/mL) and remained higher than or close to 1 ng/mL until the 14th day after injection. This initial study showed that a single injection of 30 mg BIM-LA effectively suppressed GH and IGF-I secretion for at least 14 days, in accordance with the kinetics of the drug in plasma. Based on the results of this initial study, 30 mg BIM-LA were injected twice monthly for 6 months in all 14 patients. All of the subjects had a basal evaluation before treatment with BIM-LA and were then subjected to assessment of clinical, pituitary, and hormonal parameters. Patients were evaluated after 3 and 6 months of treatment on the same basis as that previously used when starting the BIM-LA therapy. Plasma BIM levels were measured monthly. Clinical signs of acromegaly improved during the treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Acromegaly↗

PubMed1992

[Consistency of the histologic diagnosis of Lauren's classification of gastric cancer].

BACKGROUND: Lauren's classification of gastric cancer is usually followed in epidemiological studies thus requiring evaluation of its reproducibility. This classification defines 2 principal histological types: intestinal and diffuse with different proportions in high and low risk areas possibly being associated to different causal factors. METHODS: The concordance diagnosis in an aleatory sample of 81 gastric carcinomas stratified according to the participation of 14 hospitals in an epidemiological study of 354 cases and 354 controls was analyzed. The initial diagnosis carried out was compared by more than 20 pathologists with the reclassification diagnosis by consensus of 2 pathologists by the proportion of agreement or concordance observed in the kappa index. Keeping the final reclassification by consensus as a reference, sensitivity, specificity and predictive values were also calculated. RESULTS: The proportion of concordance observed was of 78% for the intestinal and 90% for the diffuse with a kappa index of 0.55 and 0.74, respectively. Sensitivity for the intestinal type was of 88% and for the diffuse 81% with specificity being of 67% in the intestinal and 93% in the diffuse. CONCLUSIONS: Subjectivity in the interpretation of certain parameters necessary for histological diagnosis may be reduced by the elaboration of protocols in which the principal histological criteria to follow are detailed. Nonetheless, the distinction made between the two principal types, intestinal and diffuse, is valid enough to be used in multicenter epidemiological studies and in comparative studies.

Case-Control Studies↗

PubMed1992

[Perioperative blood transfusion and prognosis in colorectal cancer. Analysis of a series].

The relationship between survival after surgical resection of colorectal carcinoma, and perioperative blood transfusion was studied retrospectively. "Curative" surgery was performed in 164 cases of colorectal cancer--stages B and C--, 72 of them received red-cell concentrates perioperatively. Multiple regression analysis did not show any deleterious effect of blood transfusion on the survival of the surgically treated patients (P = 0.941). The volume of the blood derivative received neither seems to influence their outlook. As it was expected a higher rate of transfusion occurred among rectal cancer patients. Mechanisms and factors involved in this controverted issue are discussed and literature is widely reviewed.

Actuarial Analysis↗

PubMed1992

[Role of the vagal system in changes in small intestinal motility induced by psychological stress. Experimental study on dogs].

The objectives of the present study were: 1) to describe the modifications in motility of the small intestine in response to situations of psychic stress during fasting and postprandial periods. 2) To analyse the possible involvement of the vagal system in these modifications. For this we used a total of 40 dogs. The motility of the small intestine was recorded using electromyography techniques (monopolar electrodes) and manometric techniques (submucous microballons). The stress stimulus consisted in the complete body immobilization of the animal in plaster. We show that stress induced a significant increase in the intestinal motility index (percentage of show waves followed by the action potential) in the three locations of the intestine studied (duodenum, angle of Treitz and proximal part of the jejunum) during the fasting (p less than 0.001) and postprandial periods (p less than 0.001). Finally, we demonstrate that vagotomy prevents the effect of hypermotility causes by the psychic stress. We can conclude that psychic stress does indeed modify the normal motility of the small intestine, both in the fasting and postprandial periods, and the vagus is implicated in this hypermotility response.

Animals↗

PubMed1990

Influence of average molecular weights of poly(DL-lactic acid-co-glycolic acid) copolymers 50/50 on phase separation and in vitro drug release from microspheres.

The phase separation of fractionated poly(DL-lactic acid-co-glycolic acid) copolymers 50/50 was determined by silicone oil addition. Polymer fractionation by preparative size exclusion chromatography afforded five different microsphere batches. Average molecular weight determined the existence, width, and displacement of the "stability window" inside the phase diagrams, and also microsphere characteristics such as core loading and amount released over 6 hr. Further, the gyration and hydrodynamic radii were measured by light scattering. It is concluded that the polymer-solvent affinity is largely modified by the variation of average molecular weights owing to different levels of solubility. The lower the average molecular weight is, the better methylene chloride serves as a solvent for the coating material. However, a paradoxical effect due to an increase in free carboxyl and hydroxyl groups is noticed for polymers of 18,130 and 31,030 SEC (size exclusion chromatography) Mw. For microencapsulation, polymers having an intermediate molecular weight (47,250) were the most appropriate in terms of core loading and release purposes.

Drug Compounding↗

PubMed1990

[Electrocoagulation in cancer of the rectum].

Twenty-six patients were treated by electrocoagulation of rectal adenocarcinoma between 1975 and 1985 at Santa Cruz y San Pablo Hospital, out of a total of 410 patients operated on for cancer, that is, 6.34% of the total number of cases. Eight cases were excluded from this review because of insufficient data. Indications for electrocoagulation were as follows: contraindication of radical surgery due to a severe underlying disease or old age, patient refusal to undergo surgery or colostomy, as a palliative measure in extremely advanced neoplastic disease, and lastly, in cases where local excision was contraindicated (because of tumor size, the lesion not being removable or being affixed to the muscular plane). The overall survival rate among patients treated with intent to cure was 54.5%. We also present the indications and contraindications of this surgical technique.

Adenocarcinoma↗

PubMed1990

[Evaluation of an immunoenzyme technique for the diagnosis of syphilis].

A comparative study of an enzyme immunoassay (EIA Captia Syphilis Mercia), FTA-Abs and VDRL to detect anti-Treponema pallidum antibodies was carried out in overall 290 subjects: 113 had a diagnosis of syphilis (40 primary and 73 secondary) and 117 were controls (40 with nonsyphilitic ulcers, 52 with falsely positive VDRL and 85 healthy subjects). The overall correlations between EIA Captia and FTA and with VDRL were 92% and 72%, respectively. The sensitivity of the method was 82%, with 98% specificity.

Antibodies, Bacterial↗