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Biomedical subjects

M Carrasco

Publications and source records attributed to M Carrasco.

14 recordsLinked to original sources
PubMed1992

[H2 antagonists as inhibitors of cytochrome P-450 in rat liver: in vitro and in vivo effects].

Cytochrome P-50 is a well known participant in the metabolism of xenobiotics as well as an activator or inactivator of hepatotoxic substances and carcinogenic agents. H2 antagonists, cimetidine, famotidine and ranitidine were used to inhibit cytochrome P-450 in rat liver. After 200 mg cimetidine, 85% inhibition of cytochrome P-450 in vitro and 50% in vivo were demonstrated through demethylation of aminopyrine. Inhibition was further confirmed by differential absorption spectra (Type II). The percentage inhibition obtained with famotidine or ranitidine were lower than those obtained with cimetidine. Inhibition of the microsomal oxidative system by cimetidine could lead to decreased production of superoxide radicals and protection against damage induced by toxic agents activated in the liver.

Administration, Oral↗
PubMed1991

[A new case of autochthonous visceral leishmaniasis in Bolivia].

A sixth autochthonous case of visceral leishmaniasis is reported in Bolivia. It is also the fourth case detected in the Yungas Valley (Department of La Paz) confirming the long-term existence of the disease in this area where cases of canine leishmaniasis and natural infestation of the phlebotomine sandfly, Lutzomyia longipalpis, were previously reported.

Antimony Sodium Gluconate↗
PubMed1991

[Empty sella turcica with intrasellar herniation of the optic chiasm].

We here present the case of a patient who starts with a progressive vision loss, observing in the radiologic exam herniation of optic chiasma in a primary empty sella turcica. Based on this case, we have performed a review of this clinical picture and point out the most important aspects in the literature.

Cranial Nerve Diseases↗
PubMed1990

Visual space-time interactions: effects of adapting to spatial frequencies on temporal sensitivity.

To study how adaptation to spatial frequency patterns affects temporal sensitivity in vision, observers were selectively adapted for 4 min to either a high- or a low-spatial-frequency sinusoidal grating (12 and 2 cpd, respectively). Their sensitivities to modulation of a blurred patch at high or low temporal frequencies (12 Hz and 2 Hz, respectively) were measured, before and after the adaptation period, by using the yes/no task of signal detection theory. The data consistently indicated that spatial adaptation differentially affected the observers' sensitivities to temporal signals. Specifically, when the observers were adapted to low spatial frequencies, their sensitivity to low temporal frequencies was reduced; when they were adapted to high spatial frequencies, their sensitivity to high temporal frequencies was increased. These results have implications for the psychophysical measurements of temporal and spatial sensitivity, as well as for the issue of the separability of spatial and temporal properties of individual channels.

Attention↗
PubMed1990

Disseminated histoplasmosis in AIDS. Clinicopathologic features in seven patients from a non-endemic area.

Although the clinical and epidemiologic features of progressive disseminated histoplasmosis (PDH) in the acquired immunodeficiency syndrome (AIDS) have been well described, the pathologic and pulmonary aspects remain to be fully defined. A retrospective review of three patients and a prospective study of four more with PDH and AIDS recently admitted to an inner city hospital in a non-endemic area were used to elucidate these features more fully. All patients were men aged 23 to 46 years, born in endemic areas, who had immigrated to the US seven to 15 years before the onset of their illnesses. Five had been exposed to human immunodeficiency virus (HIV) through intravenous drug use (one was also a homosexual), and two through heterosexual contacts. Respiratory symptoms were evident in five of the seven patients, fever in seven, weight loss in seven, hepatomegaly in four, splenomegaly in three, peripheral adenopathy in three, and gastrointestinal symptoms in three. PDH was the initial or only opportunistic infection in five patients. Bilateral nodular infiltrates (4/7), bilateral interstitial infiltrates (2/7), and mediastinal adenopathy associated with pleural effusion (1/7) were the chest roentgenographic findings. Histoplasma capsulatum was isolated from five of five bronchoalveolar lavages, four of four transbronchial biopsies, one of one endobronchial biopsy, one of one brushing, one of one pleural biopsy, three of three lymph node biopsies, two of two bone marrow biopsies, one of one liver biopsy, and three of four peripheral blood smears. Granuloma formation was seen in only three of 12 biopsies. There were ten or more fungi per monocyte in almost all tissues, some with extracellular forms.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Complications of acute gastroenteritis caused by Salmonella no typhi].

A review was made of the histories of 125 adult patients admitted for acute gastroenteritis (GEA) due to Salmonella no typhi. The complications that appeared in the series are analyzed. A total of 16 patients (12.8%) presented complications: the most common was bacteremia, 3 had renal tubular necrosis, 2 alithiasic cholecystitis that required surgery, 2 toxic megacolon, 2 rectal hemorrhage, 1 erythema nodosum and 1 intestinal perforation. The authors review the features of each complication.

Acute Disease↗
PubMed1987

Spanish activities in prevention and control of hospital infection.

Spanish activities in prevention and control of hospital infection began in an organized manner in 1970. Throughout the decade we worked on the following aspects: promotion of an Infection Control Committee, promotion of a unit for Epidemiological Surveillance for Hospital Infection and design of sanitary control of the hospital environment. Nowadays more than 50% of Social Security Hospitals have a basic structure suitable for following a good surveillance system and only 10% do not perform any control activities. The National Prevalence Survey (1986) provides the following information: 11.2% of hospital acquired infection, 18.1% of community acquired infection. The most frequent location was in the urinary tract (29%). E. coli was the predominant bacteria and 33% of infections were in patients with more than 65 years of age. Today the magnitude of hospital infection is known and we have developed control and preventive programs but the cost efficacy proportion has not been assessed yet.

Cross Infection↗
PubMed1986

A test of the spatial-frequency explanation of the Müller-Lyer illusion.

Previous investigations have shown that the response of spatial-frequency-specific channels in the human visual system is differentially affected by adaptation to gratings of distinct spatial frequencies and/or orientations. A study is reported of the effects of adaptation to vertical or horizontal gratings of a high or a low spatial frequency on the extent of the Brentano form of the Müller-Lyer illusion in human observers. It is shown that the illusion decreases after adaptation to vertical gratings of low spatial frequency, but seems unaffected otherwise. These results are consistent with the notion of visual channels that are spatial-frequency and orientation specific, and support the argument that the Müller-Lyer illusion may be due primarily to lower-spatial-frequency components in the Fourier spectra of the image.

Adaptation, Physiological↗