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Biomedical subjects

A Calderón

Publications and source records attributed to A Calderón.

At least 19 recordsLinked to original sources
PubMed2006

Lercanidipine is an effective and well tolerated antihypertensive drug regardless the cardiovascular risk profile: The LAURA study.

To determine whether the antihypertensive effectiveness of lercanidipine was independent of the different cardiovascular risk levels. Patients with treated or untreated mild-to-moderate essential hypertension were included in a multicentre, prospective, non-comparative, open-label study. Patients received lercanidipine (10 mg/day, uptitrated to 20 mg/day) during 6 months. A total of 3175 patients, age 63 +/- 10 years, 51% women, were included. The cardiovascular risk was low in 237 patients, medium in 1396, high in 722, and very high in 820. At baseline, blood pressure (BP) was 159.5 +/- 11.7/95.2 +/- 7.4 mmHg. BP was progressively higher according to increase in cardiovascular risk. After 6 months of treatment, BP was 136.0 +/- 9.7/79.7 +/- 6.8 mmHg. The decrease in systolic BP and diastolic BP at each follow-up visit compared with baseline was statistically significant both in the intergroup and intragroup comparisons (p < 0.001). Mean decreases of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were -18.5/-13.8 mmHg in the low risk group, -23/-15.2 mmHg in the medium risk group, -24.4/-16.1 mmHg in the high risk group, and -27.4/-17.4 mmHg in the very high risk group. Most frequent side effects were oedema (5.1%), headache (3.3%), flushes (2.5%), and asthenia (1%). Only 1.7% of patients discontinued antihypertensive medication because of adverse events. Tolerability of lercanidipine was independent of the cardiovascular risk group. Lercanidipine was effective and well-tolerated in patients with mild-to-moderate hypertension in the daily practice. The effectiveness and safety of the drug were independent of the degree of cardiovascular risk.

Aged↗
PubMed2003

Photoacoustic determination of iron in corn meal.

We report here on the use of the photoacoustic technique for the determination of low concentrations of total iron in corn meal samples. The determination of this element in food is of considerable interest because several foods are currently enriched with it at proper levels in order to increase the resistance of people, after consumation, to several diseases, such as anemia. The proposed technique is based on an open photoacoustic cell configuration in conjunction with a suitable colorimetric method. We applied it to a measurement of the total iron concentration in corn meal samples. The results agree very well with those obtained using a conventional spectrophotometric method, showing the possibilities of new experimental methodologies based on photothermal methods to perform this kind of study, with the advantage of a higher sensitivity and increment of the range of appreciable absorbance.

Acoustics↗
PubMed1999

Magnetic resonance study of the pancreatic duct.

AIM: to prospectively determine the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) in the evaluation of the normal and diseased pancreatic duct. METHODS: patients seen during a 6-month period with a diagnosis of biliary tract or pancreatic disease underwent endoscopic retrograde cholangiopancreatography (ERCP) after a previous MRCP. The pancreatic duct was evaluated with both techniques in 37 patients. RESULTS: the pancreatic duct appeared normal in ERCP in 27 patients, and also appeared normal in MRCP in 25 of these patients (specificity 93%). ERCP showed moderate-severe pancreatic duct dilation in 8 patients, in whom the same diagnosis was reached with MRCP (sensitivity 100%). The causes of dilation were chronic pancreatitis (2 patients), pancreatic cancer (3 patients) and ampullary tumor (2 patients); in 1 patient the findings with both techniques were suggestive of neoplasm of the head of the pancreas or focal chronic pancreatitis. Pancreas divisum was diagnosed in 2 patients by both methods, and the predominant dorsal duct as well as the ventral duct were visualized by MRCP. CONCLUSIONS: MRCP is an accurate technique for evaluating the normal or diseased pancreatic duct, and for determining the underlying disease.

Aged↗
PubMed1996

Hartmannella vermiformis isolated from the cerebrospinal fluid of a young male patient with meningoencephalitis and bronchopneumonia.

Meningoencephalitis and bronchopneumonia were documented in a patient from Peubla, Mexico. The patient began with symptoms and signs of a common flu and 12 days after the onset of his disease he was admitted to the hospital presenting symptoms and signs of meningoencephalitis. The clinical course evolved into an endocraneal hypertension syndrome with bronchopneumonia, coma and death. Wide-spectrum antibiotics, immunosuppressive and anti-tuberculosis therapy were unsuccessfully administered. Important antecedents were degree I malnutrition and repeated contact with polluted water. Post-mortem autopsy was not performed. Gram-positive cocci were isolated from the spinal fluid 2 days after admission, and then active amebae were isolated from three different samples of the spinal fluid at days 16, 18 and 19 after admission. Such samples were concentrated and inoculated onto specific culture media. Identification of amebae was based on their morphology and biochemistry. All amebae were Hartmannella vermiformis. Amebae were apparently not the cause of the disease and might be considered as an opportunistic colonizer which may have caused the evolution of the disease to become worse.

Acid Phosphatase↗
PubMed1994

Prospective epidemiological study of invasive Haemophilus influenzae disease in adults.

The incidence and characteristics of invasive Haemophilus influenzae disease were studied in 43 adult patients admitted to the acute care hospitals in El Vallés County (Barcelona, Spain) between January 1987 and June 1992. The annual incidence of Haemophilus influenzae disease was 1.2 per 100,000 inhabitants. Pneumonia occurred in 24 patients, meningitis in five, intraabdominal infections in three, obstetric infections in two, epiglottitis in two and cellulitis in one. In six patients the source of infection was unknown. Ten (23%) of the infections were hospital acquired. Underlying conditions were diagnosed in 30 (70%) patients. Nontypeable Haemophilus influenzae strains predominated in all adult age groups. Sixty-one percent of type b and 34% of nontypeable strains were ampicillin resistant (p = 0.08). Multiple antibiotic resistance was also high among type b (53%) and nontypeable (18%) strains. The mortality rate was significantly higher in patients with pneumonia, bacteremia from an unidentified focus or shock at presentation.

Adolescent↗
PubMed1993

Pathogenic and free-living amoebae isolated from swimming pools and physiotherapy tubs in Mexico.

A protozoological survey was done to isolate free-living amoebae from swimming pools and physiotherapy tubs in Mexico City. Amoebae were isolated by culture in nonnutritive agar medium combined with Escherichia coli. Identification of the isolates was done by morphology using specialized taxonomic keys and by isoelectric focusing of total proteins and isoenzymes in agarose. Pathogenicity of the isolates was determined in 3-week-old mice by intracerebral and intranasal inoculations. Statistical tools were used to determine the existence of significant differences on the incidence and diversity of the isolates in relation to the two types of water bodies analyzed. Water and environmental temperatures, pH, and chloride concentrations were determined at each sampling site. Twenty-nine amoebic strains from eight genera were isolated. Most frequently found were specimens of the genera (Acanthamoeba (with four pathogenic strains), Vahlkampfia, Hartmannella, and Naegleria. Amoebae were isolated more frequently in spring and summer, and could not be recovered from pools with chloride levels of 5.31 mg/ml or more. This survey demonstrates that chloride concentrations commonly used in recreative pools and therapy tubs are not sufficient to eliminate viable cysts of most free-living amoebae. Significantly higher numbers of isolates were retrieved from the pools than from the tubs.

Amebiasis↗
PubMed1993

[The analgesic and anti-inflammatory effects of Drymonia serrulata (Jacq.) Mart].

The authors experimentally demonstrated that an aqueous fraction of Drymonia serrulata (Jacq.) Mart. has peripheral, but not central, analgesic activity, and that it also has a dose-dependent anti-inflammatory activity at 24 and 96 hours. The experimental results indicate that the etnomedical use of this plant by the Guaymi Indians may have some scientific validity

Animals↗
PubMed1988

Sleep patterns in a chelonian reptile (Gopherus flavomarginatus).

Individuals of Gopherus flavomarginatus, previously adapted to experimental conditions were chronically implanted for polygraphic recordings. Four different states of vigilance were observed:. Active wakefulness, quiet wakefulness, quiet sleep and active sleep. EEG was polymorphic and irregular showing a decreasing tendency in frequency and amplitude when passing from wakefulness to quiet sleep. Heart rate decreased with sleep but it was slightly higher during active sleep than quiet sleep. Motor automatisms were present during active sleep being sometimes accompanied by ocular movements. This sleep always appeared after long periods of quiet sleep. Its average duration from animal to animal varied between 9.15 and 13.62 sec. Reaction threshold increased during sleep. The conclusion is that Gopherus flavomarginatus shows two phases of sleep similar to slow and paradoxical sleep in mammals.

Animals↗
PubMed1988

Sleep patterns in the bird Aratinga canicularis.

Behavioral and electrophysiological features of sleep and wakefulness were studied in chronically implanted adult parakeets, Aratinga canicularis. Four states of vigilance were observed: (1) Wakefulness. It is divided into active and passive. During this state there are generalized motor manifestations which are more frequent and intense in active wakefulness. Cerebral activity is fast and of low amplitude. (2) Drowsiness. Motor activity is notably lower. Blinkings become progressively less frequent. Electroencephalographic patterns are constituted by waves of variable amplitude and frequency. It constitutes 40.7% of the nychthemeral cycle. (3) Slow Wave Sleep (SWS). Animals remain immobile with eyes closed and eye movements are at their lowest frequency. Cerebral activity is slow and of high amplitude. It constitutes 14.7% of the nychthemeral cycle. No sleep spindles are present. (4) Paradoxical sleep (PS). The bird's head tends to drop due to additional muscular relaxation; its eyes remain closed but there are bursts of ocular movements. The EEG is similar to that of wakefulness. This state lasts 7.14 sec on average and occupies 1.98% of the nychthemeral cycle. It is always preceded by SWS. The absence of sleep spindles could be due to the differences in cerebral development compared with mammals.

Animals↗
PubMed1985

Isolation and identification of Rickettsia rickettsii from the rabbit tick (Haemaphysalis leporispalustris) in the Atlantic zone of Costa Rica.

During the ecological studies done in Costa Rica on Rocky Mountain spotted fever, we have been able to isolate 2 strains of rickettsiae from the rabbit tick Haemaphysalis leporispalustris, indistinguishable from R. rickettsii isolated from humans in our country. Moreover, serological evidence of this agent was demonstrated in convalescent guinea pigs and in the sera of the wild rabbit (Sylvilagus braziliensis).

Animals↗
PubMed1982

Detection of signs of estrus in the charolais cow and its Brahman cross under continuous observation.

In order to study the characteristic signs of an induced estrus in beef cattle maintained in the tropics, 31 animals, 16 pure Charolais and 15 Charolais/Brahman cross, were continuously observed during the first 100 hours following prostaglandin injection. The animals were pastured in a field of approximately 3 hectares. A highly significant relationship (P < 0.01) seemed to exist between behavioural tendencies and the interval following the onset of estrus. Behaviour included butting, attempts to mount, smelling of genitalia (active) and allowing to be mounted and have genitalia smelled (passive). No consistant pattern of sexual activity could be established since some animals were more active than others. Mounts were observed to occur between 6 and 9 in the morning (33%), 9 and 12 at night (16%) and midnight and three in the morning (13%). Differences existed between the Charolais and the Brahman cross with respect to the number of mounts (P < 0.05) and in the response to an induced estrus (P < 0.05). No correlation was found between grazing habits and sexual activity, the former expressed as the number of animals standing up during each hour.

Journal Article↗
PubMed1982

Rotavirus viral RNA electrophoresis in hospitalized infants with diarrhea in Santiago, Chile.

Viral RNA electrophoresis technique was used to detect rotavirus in 226 children under 2 years of age with acute diarrhea, admitted to the Roberto del Río Hospital in Santiago, Chile, during the period of June 1979 through May 1980. A group of 50 children included in the aforementioned sample, admitted in winter, was compared with a control group of 25 infants without digestive pathology. In these groups, rotavirus was detected in 20 out of 50 children with diarrhea (40%) but not in the controls (0%). A positive diagnosis of rotavirus was found in 66 out of the total of 226 patients (29.2%); its monthly distribution ranged between a maximum of 83.3% (June) and a minimum of 11.1% (October).

Chile↗