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Biomedical subjects

I Ruiz

Publications and source records attributed to I Ruiz.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Experimental gastro-esophageal reflux in rats].

Aiming at developing a model of experimental gastro-esophageal reflux (GER) in the rodent we have tested three surgical procedures (distal esophageal myectomy (EM), esophago-gastrostomy (EG) and end-to-side esophago-jejunostomy (EJ) in three groups of 12 Wistar rats weighting 175 to 225 g. We have used for comparison a control group of unoperated rats. We have checked radiologically and by lower esophageal pH-monitoring that all three procedures induced GER and that this was absent in control animals. Six individuals in each group were sacrificed at the 7th day and the remaining six at the 14th day. At that time blood was drawn and esophageal tissue was collected for histological studies. Animals in the EM group were healthy after operation, had little vomiting and conserved their initial weight. Those in the EG and EJ groups had frequent vomiting, and lost weight. These symptoms were particularly severe in the EJ group. Animals in the control, EM and EG groups had histologically normal esophageal mucosa at the 7th and at the 14th days whereas those in the EJ group had grade 2-3 esophagitis at the 7th and grade 3 esophagitis at the 14th days. Esophageal epithelium in the rat is keratinized and therefore highly resistant to acid GER as attested by its excellent tolerance to reflux in the EM and EG groups. On the contrary, the presence of gastric and pancreatic juices and bile in the refluxate, like in the EJ group, digests the superficial layers of the epithelium and induces severe esophagitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1990

[Primary surgical pathology of the epiploon].

In the last nine years we have operated upon six children (eight males and two females) with primary omental pathology. The age of our patients ranged from five to eleven years with the exception of a newborn prenatally diagnosed of lymphangioma. All the remaining children had abdominal pain and right iliac tenderness for an average of two days. All had leukocytosis and left shift. Vomiting and fever were present only in one instance. In no case the mass was palpated preoperatively. The initial diagnosis was acute appendicitis in all cases. A patient suffered, one year after operation, a second acute clinical picture and the omental mass could be revealed [correction of decealed] preoperatively. At operation there was free intraperitoneal fluid in six instances (three times bloody, two times clear and one purulent). Surgical findings (nine operations) were: three omental segmental infarctions (primary in two cases and secondary to torsion in one), three segmental epiploitis in two patients (one acute, one chronic, one secondary to foreign body), two cystic lesions (one lymphangioma, one hydatic cyst) and one benign tumor (fibromatosis).

Child↗
PubMed1990

[Bacteremia and fungemia in patients with AIDS. Study of 56 episodes].

We report 56 episodes of bacteremia and fungemia in 45 patients (23%) out of overall 193 cases of AIDS. 41% of the isolates were gram-negative bacilli, with a predominance of Salmonella enteritidis (30%), most of them community-acquired. Gram-positive cocci (18 episodes) were hospital-acquired in 61%, with a predominance of Staphylococcus sp (10 cases). Mycobacteria and Cryptococcus neoformans were isolated in 8 patients. 88.8% of our patients with cryptococcosis (8/9) had positive blood cultures. 76% of the episodes (43/56) were community-acquired, with a high incidence of primary bacteremias (59%). 48% of the patients were cured, whereas 27% died from causes related with the bacteremia.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Experimental malformations of the body wall in the chick embryo].

The rapidly growing possibilities of prenatal diagnosis and intrauterine manipulation of the malformed fetus have created the need for animal experimental models as simple and easy to handle as possible. We report on our experience with the induction of body wall defects in the chick embryo. Laparoschisis was produced by evisceration of the bowel through the umbilical stalk and its exposition to the allantoic fluid at the 14th day of incubation. Exomphalos, Cantrell's Pentalogy and Spina Bifida were induced by sterile aspiration of 5 ml of egg albumen at the 24th hour of incubation. All embryos were recovered and studied at the 19th day of incubation. The results can be summarized as follows: ninety-four (51%) of the 184 embryos operated for bowel exteriorization survived and 42 (45%) had intestinal lesions identical to those found in human laparoschisis. Two-hundred ans seventy (45%) of the 602 embryos treated by albumen extraction survived and 197 (73%) had no visible malformations, whereas either exomphalos or Cantrell's pentalogy were found in 37 (14%) and spina bifida was observed in the remaining 36 (13%). All lesions were strikingly similar to the human ones. These models could facilitate research on the above-mentioned malformations without the major difficulties and expenses inherent to fetal research in mammals. The chick embryo, for many decades a favorite model for embryologists, is a tool for fetal research as well and opens some perspectives in this field even for relatively modest laboratories.

Abdominal Muscles↗
PubMed1990

[Laparoscopic findings in liver fascioliasis. Study of 13 cases].

The laparoscopic findings in 13 patients with liver fasciolasis are described. Diagnosis was made in three cases in base of the presence of ova Fasciola Hepatica in the patient's faeces and in 10 cases, because they fulfilled the following conditions: ingestion of fresh watercress, eosinophilic count exceeding 30%, positive serologic tests, eosinophilic granulomas with Charcot-Leyden crystals in liver biopsy and good response to treatment with dihidroemetine or bithionol. Nine cases (68.2%) showed hepatomegaly. In 12 of 13 (92.3%) lesions suggestive of hepatic distomatosis were found. Hepatic nodules of different sizes and shapes could be seen in 10 patients (76.9%), Glisson capsule was involved in five cases (38.4%) and peritoneum in three (23%). The latter was always affected with the liver but, on the other hand, liver capsule was found affected alone in two cases. In our experience, laparoscopy with liver biopsy is an important method for diagnosis of abdominal fasciolasis.

Adult↗
PubMed1989

Utilization of benzodiazepines in Chile during 1982-1986.

The consumption of benzodiazepine drugs (BDZ) in Chile in the period 1982-1986 has been studied by the DDD method. National use was assessed using drug import forms as a source of information, assuming that the total amount imported was manufactured and consumed in the same year. The utilization did not show a constant pattern, being 32.7, 33.6, 50.2, 34.9, and 31.3 DDD 1000 per inhabitants per day in 1982, 1983, 1984, 1985 and 1986, respectively. During the study period, diazepam was the most commonly used agent amongst anxiolytic BDZ, reaching a peak of 27.1 DDD per 1000 inhabitants per day in 1984, and flunitrazepam was the most popular hypnotic, attaining its maximum in 1986 (6.4 DDD per 1000 inhabitants per day). The use of BDZ at community pharmacy level was also evaluated, employing the International Marketing System (IMS) as the source of information. At that level the pattern of utilization showed a constant increase during the study period, being 14.9 and 25.8 DDD/1000 inhabitants/per day in 1982 and 1986, respectively. In community pharmacies the anxiolytic BDZ most often consumed was diazepam (maximum 9.1 DDD per 1000 inhabitants per day in 1985), and the commonest hypnotic was flunitrazepam (peak 6.0 DDD per 1000 inhabitants per day in 1986). National consumption of BDZ appeared higher and more variable than use at the community pharmacy level, but in both there was greater usage of anxiolytic than of hypnotic BDZ, and diazepam and flunitrazepam were the most popular agents.

Anti-Anxiety Agents↗
PubMed1989

Adenosine deaminase in body fluids: a useful diagnostic tool in tuberculosis.

The performance of a colorimetric ADA determination in body fluids other than serum in the diagnosis of tuberculosis was assessed in 1063 patients from whom pleural (600), peritoneal (136), pericardial (77), or cerebrospinal (250) fluids were obtained. In exudative pleuroperitoneal and pericardial effusions, an ADA decision level of 0.71 mu kat/L displayed a sensitivity of 1.00, and was higher than those of histologic (0.83) and bacteriologic (0.62) studies. At this level, ADA reached a specificity of 0.92 and efficiency of 0.94. In cerebrospinal fluid, an ADA catalytic concentration above 0.15 mu kat/L strongly suggests tuberculous meningitis in patients older than 7 years (sensitivity 1.00, specificity 0.99 and efficiency 0.99). ADA results obtained with a UV-method were closely correlated with those of the colorimetric method in pleuroperitoneal effusions (r = 0.989) and in cerebrospinal fluids (r = 0.905). Sample blanks should be processed, otherwise false positive results may be found in non-tuberculous cerebrospinal fluids (5.3%) and pleuroperitoneal effusions (3.8%).

Adenosine Deaminase↗
PubMed1989

[Use of antimicribials at a University Hospital (1983-1987)].

We studied total utilization of antimicrobials from 1983 to 1987 at the Clinical Hospital, University of Chile. The method of defined daily doses suggested by the WHO was used for analysis. The peak value occurred in 1984 (28.3 DDD/1000 patient-days), the lowest in 1987 (19.9). Penicillins were the most frequently used drugs, followed by aminoglycosides and cephalosporins. The latter group was mainly used at the Intensive Care Unit (37.5% of total cephalosporin use) and by the Intermediate Surgical Unit (35.1%). Use of antimicrobials at the Neurology and Dermatology services represented 5.3 and 4.9% of total utilization, respectively (excluding cephalosporins). These methods may be employed for comparisons of antimicrobials use among Chilean hospitals.

Adult↗
PubMed1988

Adenosine deaminase activity in rheumatoid pleural effusion.

The activity of adenosine deaminase was studied in nine cases of rheumatoid pleural effusion, showing an increase in enzyme activity in all. Rheumatoid arthritis seems unique, however, as it cannot be differentiated from pleural tuberculosis on the basis of this test. Selective increase of adenosine deaminase in both conditions is attributed to stimulation of T lymphocytes in the pleural fluid.

Adenosine Deaminase↗
PubMed1987

Disposition kinetics of dibekacin in normal subjects and in patients with renal failure.

Dibekacin pharmacokinetics was studied in ten healthy volunteers and six patients with renal failure presenting Clcr less than 10 ml X min-1 per 1.73 m2 of body surface, given as a slow intravenous bolus to the volunteers and as a 30-minute intravenous infusion to the patients. The antibiotic was assayed in plasma and urine by means of a microbiological method using Bacillus subtilis. A two-compartment kinetic model was used to describe the bi-phasic decline of the plasma concentration thus establishing the different pharmacokinetic parameters. Elimination parameters beta, k10 and total body clearance were markedly diminished in renal patients (p less than 0.001): t1/2 beta was 2.0 h, k10 = 0.016 min-1 and Cl = 0.87 ml X min-1 kg body weight in normal subjects and t1/2 beta = 21.4 h, k10 = 0.0011 min-1 and Cl = 0.131 ml X min-1 per kg in the patients. Other kinetic parameters, as distribution (alpha) and transfer (k12, k21) constants were lower in patients than in volunteers. Also the different terms of volume of distribution of the two-compartment model (V1, Vdss, Vdarea) were significantly higher in patients than in normal subjects (p less than 0.05). A good correlation (r = 0.987) between patients' beta constant and creatinine clearance was found. A similar relationship between serum creatinine levels and disposition half-life was found (r = 0.955). Urinary recovery at 24 h was 89.0% of the dose given to normals and 15.8% of the dose given to patients.

Adult↗
PubMed1987

Influence of the assessment of the severity on the frequency of adverse drug reactions (ADRs).

Sometimes it is difficult to compare data coming from different drug monitoring studies because of differences in methods, training of the monitors and other reasons. Many algorithms have been designed for permitting the objective and reproducible assessment of the causality of ADRs, but there is a lack of this kind of assessment for the severity of ADRs. This work was developed in order to show how important the standardized assessment of the severity of ADRs could be. For that purpose the same drug surveillance data were used for obtaining the frequency, characteristics and predisposing factors of ADRs, first considering all definite and probable ADRs--independently of their severity (study I)--and excluding after those considered as mild (study II). By means of an intensive prospective drug surveillance program, 2,559 patients hospitalized at the Medicine Service of the Clinical Hospital of the University of Chile were surveyed. The found frequencies of ARDs were 34.2% and 20.6% for study I and II, respectively. In both studies gastrointestinal and metabolic systems were the most ADRs-affected systems but some differences on adverse signs and/or symptoms were observed. For example, in study I the three most frequent reactions were hyponatremia, hypochloremia and hypokalemia while in study II the three commonest reactions were hypokalemia, vomiting and hypochloremia. In both studies similar characteristics of beginning and probability of ADRs were found, and the highest part of the reactions was dose-dependent. But when mild reactions were excluded (study II) an increase on the proportion of dose-independent ADRs was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Adverse drug reactions (ADRs) in patients with heart diseases. Comparison between patients without and with heart failure.

Adverse drug reactions (ADRs) may be more frequent in patients who present some diseases. By means of an intensive prospective drug surveillance work, 492 patients with heart diseases, hospitalized at the Department of Medicine of the Clinical Hospital of the University of Chile, were studied in order to determine the frequency and characteristics of ADRs. ADRs were significantly more frequent in patients with heart failure (HF) (30.0%) than in those without HF (22.7%)(p less than 0.05). Patients presenting HF developed more metabolic disturbances than patients not presenting HF (p less than 0.001). Furosemide was the most frequently used drug in both groups, but treatment with it was longer in patients with HF who presented a significantly higher frequency of adverse reactions to this diuretic (p less than 0.05). 89.9% of ADRs in patients without HF and 93.8% of ADRs in those with HF, were dose-related effects. Analyses of some predisposing factors to ADRs, such as age, number of drugs administered, duration of hospitalization, ADR or allergy histories and presence of a renal failure, did not explain differences found between ADRs in patients without and with HF. These findings suggest that heart failure may be a determinant of frequency and characteristics of ADRs.

Acetyldigitoxins↗