[Anatomopathologic diagnosis of Alzheimer's disease].
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Alzheimer Disease↗
Biomedical subjects
A Moreno
Publications and source records attributed to A Moreno.
Regulation of heme-controlled eukaryotic polypeptide chain initiation factor 2 alpha-subunit kinase of reticulocyte lysates.
We have obtained highly purified preparations of the heme-controlled eukaryotic initiation factor 2 alpha-subunit (eIF-2 alpha) kinase (HCI) from rabbit reticulocyte lysates containing five different polypeptides. One of these is a 87-kDa (p87) phosphopeptide which appears to show an autokinase activity. The controlled digestion with trypsin of HCI preparations leads to the suggestion that phosphorylation of p87 is not needed for kinase activity and, furthermore, that another 89-kDa polypeptide could be the kinase catalytic subunit. In agreement with this, monoclonal antibodies directed against p87 do not interfere with eIF-2 alpha kinase activity. Moreover, the anti-p87 antibodies and those directed against the mammalian 90-kDa heat shock protein recognize the same p87 polypeptide from rabbit reticulocyte lysates. Upon incubation of the HCI preparation with hemin (5-10 microM), the eIF-2 alpha kinase is converted into an inactive form and appears to become associated with related peptides forming high molecular weight complexes which can be reversibly activated by 2-mercaptoethanol. The maintenance of the integrity of the porphyrin ring is absolutely required for kinase inactivation and although the presence of metal ion is not essential, the iron and cobalt metalloporphyrins are more effective than protoporphyrin IX. The formation of the inactive form of HCI by hemin is prevented by either N-ethylmaleimide, monoclonal antibodies directed against p87, or phosphorylation of p87. The data strongly suggest that hemin regulates eIF-2 alpha kinase activity by promoting formation of the inactive dimer HCI.p87 via disulfide bonds and direct binding of hemin. A model of HCI regulation is discussed.
Animals↗
Class IV alcohol dehydrogenase (the gastric enzyme). Structural analysis of human sigma sigma-ADH reveals class IV to be variable and confirms the presence of a fifth mammalian alcohol dehydrogenase class.
Human gastric alcohol dehydrogenase (sigma sigma-ADH) was submitted to peptide analysis at picomole scale. A total of 72 positions were determined in the protein chain, providing information on three aspects of alcohol dehydrogenase structures in general. First, the data establish the presence of a unique class of the enzyme, now confirmed as class IV, expressed in gastric tissue and separate from another novel class, now termed class V. Second, the class IV gastric enzyme has active site relationships compatible with an ethanol-active, zinc-containing alcohol dehydrogenase. Third, this enzyme class is of the variable type, like that for the 'variable', classical liver alcohol dehydrogenase of class I, and in contrast to that for the 'constant' class III enzyme. Known human alcohol dehydrogenase structures now prove the presence of at least seven human genes for the enzyme and nine for the whole protein family.
Alcohol Dehydrogenase↗
[Cryptococcosis: presentation of 26 cases].
BACKGROUND: Cryptococcosis is more frequently observed since the appearance of the acquired immunodeficiency syndrome (AIDS). AIDS has modified the clinical and evolutive forms of the disease. This study reviews the changes produced in the infection from the context of AIDS. METHODS: The present is a retrospective study (1985-1990) including patients presenting: 1) a positive latex agglutination test (serum or spinal fluid) or 2) a Sabouraud culture positive for cryptococcus. Clinical histories were revised collecting clinical, radiologic, analytic, therapeutic and evolutive data. RESULTS: Twenty-six patients (21 males) were included in the study. Twenty patients had the human immunodeficiency virus. The clinical picture was: 22 cases with cryptococcal meningitis (13 with hematogenous participation), 3 with pulmonary cryptococcosis and one with disseminated cryptococcosis without meningeal involvement. The patients with AIDS had: greater frequency of positive hemocultures, higher serologic titers and fewer with the meningeal syndrome. The number of T4 lymphocytes was lower than 150 elements/ml in AIDS patients. In 17 patients treatment with amphotericin B and 5-fluorocytosine was administered, 5 received amphotericin B and two fluconazole and two did not receive the above since they had not been diagnosed alive. There were 6 deaths and 10 relapses in 6 AIDS patients and none in the remaining patients. CONCLUSIONS: The incidence of cryptococcosis has increased as a consequence of AIDS. In these patients the disease occurs in advanced stages of immunodeficiency and frequently in disseminated, severe and paucisymptomatic forms. Treatment is usually effective although a maintenance therapy is required to avoid relapse.
Acquired Immunodeficiency Syndrome↗
Cytoprotective effect of somatostatin in a rat model of hepatic ischemic reperfusion.
To evaluate the possible cytoprotective effect of somatostatin in hepatic ischemic reperfusion injury we used 75 adult male Wistar rats randomly separated into four groups. The rats in group 1 underwent sham operations, and those in group 2 underwent resection of the median and left lateral lobes. The rats in group 3 underwent a 90-min period of ischemia of the right lateral lobe, which we induced by temporarily occluding the right portal vein and the hepatic artery. On restoration of flow to the right lateral lobe, the median and left lateral lobes (about 80% of total liver mass) were excised (and later assayed for thymidine kinase basal activity). The rats in group 4 were given the same treatment as group 3 rats except that a saline solution of somatostatin was infused at a rate of 2 micrograms/min starting at laparotomy and lasting 24 hr. The rats in groups 1, 2 and 3 were infused with saline. Rats in groups 2, 3 and 4 were randomly assigned to two subgroups; one of these subgroups was observed until spontaneous death, and rats in the other group were killed 24 hr after the procedure for obtaining peripheral blood and liver samples. Somatostatin infusion improved the animals' survival rates from 0% (group 3) to 60% (group 4) (p < 0.05) and decreased bilirubin levels (0.78 +/- 0.17 mg/dl, n = 15 [group 4] vs. 1.69 +/- 0.04 mg/dl, n = 15 [group 3]; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Analysis of Variance↗
Persistence of hepatitis B virus DNA after reduction of viral replication in serum and liver.
Liver and serum samples from 67 children with hepatitis B chronic infection, whether or not treated with recombinant interferon, were analyzed for the presence of hepatitis B virus DNA. After follow-up, 44/67 (66%) still had serum and liver viral DNA; 23/67 (34%) were negative for serum hepatitis B virus DNA. Of the 23 children in the latter group, liver biopsy was available in 21 and viral DNA was not detected by Southern-blot in 20. In the remaining patient, viral DNA was in an episomal nonreplicative form. Polymerase chain reaction was performed in the 21 serum samples negative for viral DNA by conventional techniques and in the 21 liver samples (20 negative for hepatitis B virus DNA and 1 with episomal nonreplicative form). All liver samples resulted in a positive reaction to viral DNA by this technique. Serum viral DNA by polymerase chain reaction was detected in 15/21 (71%) of these patients. The mean of alanine aminotransferase values was similar in patients with or without hepatitis B virus DNA in serum by polymerase chain reaction. In summary, in the majority of the patients who respond to the therapy, there is a persistence of viral replication detected by polymerase chain reaction. This fact explains the persistence of serum HBsAg in these patients. However, more studies are necessary to determine the meaning of the presence of hepatitis B virus DNA that is only detectable by polymerase chain reaction.
Adolescent↗
The first field trials of the chemically synthesized malaria vaccine SPf66: safety, immunogenicity and protectivity.
This paper reports the results of the first field study performed to assess the safety, immunogenicity and protectivity of the synthetic malaria vaccine SPf66 directed against the asexual blood stages of Plasmodium falciparum. Clinical and laboratory tests were performed on all volunteers prior to and after each immunization, demonstrating that no detectable alteration was induced by the immunization process. The vaccines were grouped as high, intermediate or low responders according to their antibody titres directed against the SPf66 molecule. Two of the 185 (1.08%) SPf66-vaccinated and nine of the 214 (4.20%) placebo-vaccinated volunteers developed P. falciparum malaria. The efficacy of the vaccine was calculated as 82.3% against P. falciparum and 60.6% against Plasmodium vivax.
Amino Acid Sequence↗
Dermatofibroma with spreading satellitosis.
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Adolescent↗
Disseminated candidiasis in addicts who use brown heroin: report of 83 cases and review.
From November 1983 to April 1990, disseminated candidiasis was diagnosed in 83 heroin addicts at our institution. All patients had consumed brown heroin diluted in fresh lemon juice. Sixty-two (75%) had skin lesions, 41 (49%) had ocular lesions, and 35 (42%) had one or several costochondral tumors. Candida albicans was grown in culture or histopathologically identified in 34 cases (41%). The patients who had only cutaneous lesions were treated with ketoconazole, and they were all cured. The patients with ocular involvement received systemic amphotericin B with or without oral flucytosine; 29 of these patients developed varying degrees of vision loss. The method of treatment of costochondral tumors was not uniform; in 14 cases the lesions were resected. The one patient who died developed endocarditis involving the aortic valve. Cases of pleuropulmonary involvement, spondylitis, and large-joint arthritis have also been described among the 300 cases reported in the reviewed literature. This is a new syndrome of candidal infection in drug addicts who use brown heroin; ocular lesions are the most harmful manifestation, and loss of vision is the major sequela.
Adolescent↗
Safety and immunogenicity of the synthetic malaria vaccine SPf66 in a large field trial.
In the first field trial with synthetic malaria vaccine SPf66 in a large population naturally exposed to malaria, 9957 persons greater than 1 year old and residing on the Colombian Pacific coast received three doses of the vaccine. To evaluate vaccine safety, clinical observations were made 30 min and 48 h after each immunization. There were no adverse reactions in 95.7% of cases. In the 4.3% of cases with adverse reactions, local induration and erythema were the most frequent. In a randomly selected group of vaccinees, anti-SPf66 antibody titers were measured after the third dose: 93% of the vaccinees raised antibodies to SPf66. Among these, 55% had titers greater than 1:1600. These results demonstrate the safety and immunogenicity of the SPf66 vaccine in a large field trial.
Adolescent↗
Acetaminophen overdose as a suicidal gesture: a survey of adolescents' knowledge of its potential for toxicity.
Acetaminophen is a popular nonprescription analgesic that is often taken in overdose by adolescents during suicidal gestures. The authors hypothesized that most adolescents are naive about the toxic and lethal potential of acetaminophen in overdose. A one-page, 12-item questionnaire was administered to 169 high school students to evaluate their perceptions and knowledge in this area. Whereas only 22% of the sample underestimated the dose of acetaminophen necessary to cause harm, 40.5% underestimated the potential lethality of acetaminophen in overdose. Moreover, 17% of the sample did not believe one could ingest enough acetaminophen to cause death. The lack of knowledge about acetaminophen's potential dangerousness, its widespread availability, and an absence of early symptoms of hepatotoxicity make this medication highly dangerous to those adolescents who take it in overdose during parasuicidal behavior.
Acetaminophen↗
Septic arthritis of spinal apophyseal joint. Report of two cases and review of the literature.
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Arthritis, Infectious↗
Distribution of Alzheimer's disease amyloid protein precursor in normal human and rat nervous system.
Alzheimer's disease and cerebral amyloid angiopathies (CAA) are clinically heterogeneous diseases, but pathogenically related by the deposition of beta A4-amyloid in the brain in the form of neuritic plaques and/or vascular infiltrates. Antibodies directed against the N-terminal region of the predicted sequence of the beta A4 amyloid protein precursor (APP) were used to investigate the cellular distribution of this protein in the brain of normal humans and rats. We found a widespread presence of APP throughout the nervous tissue, including neurons, blood vessels, meningeal membranes, choroid plexus and ependymal cells. The highest APP immunoreactivity in both species was found in neuronal cell bodies and their processes, and around blood vessels. These findings may account for the clinical, pathological and aetiological differences found among the beta A4-amyloidosis.
Adult↗
Determination of the immunization schedule for field trials with the synthetic malaria vaccine SPf 66.
The synthetic malaria vaccine SPf 66 has been shown to be safe, immunogenic and effective in trials performed with controlled groups naturally and experimentally exposed to the disease. In order to continue the trials in open populations, it was necessary to standardize the vaccination characteristics. We have performed four field trials with soldier volunteers with the aim, among others, of defining the number of doses required, the intervals between applications, the protein concentration, and the adjuvant to be used. In these trials, the vaccinated individuals' immune responses were evaluated by assaying anti-SPf 66 antibody titres, in vitro growth inhibition of the P. falciparum parasite, and the vaccinees' capacity to recognize P. falciparum native proteins. From these results we conclude that the best vaccination schedule, for adults, is three doses administered subcutaneously on days 0, 30 and 180, each containing 2 mg of the synthetic polymerized petide SPf 66 adsorbed to alum hydroxide.
Adjuvants, Immunologic↗
Angiotropic malignant melanoma. Report of two cases.
Two cases of malignant melanoma are described that showed focal perineural invasion and exhibited striking tropism for small and medium-sized vessels, primarily veins. The melanoma cells proliferated within the vessel walls, expanding and replacing the muscle layer but sparing the endothelia. Intravascular invasion was not seen. Immunohistochemical studies confirmed the pattern of growth within vessel walls and the integrity of their endothelia. In one of the cases, similar vascular tropism was encountered in a capsular vein from a regional lymph node. We propose the term "angiotropic malignant melanoma" for this phenomenon and suggest that angiotropism may be a rare mechanism for melanoma spread and progression.
Actins↗
Resistance of Peptostreptococcus spp. to macrolides and lincosamides: inducible and constitutive phenotypes.
The activities of erythromycin and clindamycin against 350 Peptostreptococcus strains were studied during a 5-year period (1986 to 1991). In 5.1% of the Peptostreptococcus strains, which presented dissociated resistance (clindamycin MIC, less than or equal to 1 microgram/ml; erythromycin MIC, greater than 8 micrograms/ml), evidence of inducible macrolide-lincosamide resistance was shown. A total of 17.7% of the strains presented a constitutive phenotype; the clindamycin and erythromycin MICs for these strains were greater than 8 micrograms/ml.
Clindamycin↗
Evidence of the occurrence of calcitonin cells in the ultimobranchial follicle of the rat postnatal thyroid.
A study on thyroid glands of Wistar rats of ages ranging from 1 to 120 days was carried out. The glands were serially sectioned and stained for calcitonin using the peroxidase antiperoxidase method. All the thyroids contained ultimobranchial follicles (UBF) located partially embedded among the usual follicles but in a 5-day-old rat this structure showed an unusual position in the interstitium of connective tissue between the cartilage of the trachea and the thyroid gland. We have observed in the wall of that UBF the presence not only of resting C cells but also mitotic figures of C cells. Furthermore, on the opposite side of the same UBF an active area of formation of thyroid follicles was found. These observations provided the first evidence of the contribution of the UBF in the formation of C cells during the postnatal life of the rat. Furthermore, it is suggested that some C cells may share a common origin with ultimobranchially derived follicular cells.
Aging↗
Mitotic activity of the endocrine cells in rat thyroid glands during postnatal life.
This paper presents the results of investigations into the mitotic rates of thyroid endocrine cells in normal postnatal rats, aged 1-120 days. Our study revealed considerable age-dependent shifts in the mean mitotic activity of follicular cells and C-cells. The maximum indices of endocrine cell renewal were reached during the first 10 days of life, decreasing gradually and significantly until 25 days. At 1 month, there was a significant recuperation of the division rate for both cell types, which declined in the adult rat. These results mean that the proliferation of C-cells and follicular cells is inversely proportional to age. The preferential zone of localization of mitoses of both cell types is the central region of the thyroid lobe. The present paper provides new evidence for the postnatal origin of C-cells and follicular cells from the preexisting endocrine cells.
Aging↗