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Biomedical subjects

M Moreno

Publications and source records attributed to M Moreno.

At least 253 records · Page 14Linked to original sources

A heat stable paraoxonase (O,O-diethyl O-p-nitrophenyl phosphate O-p-nitrophenyl hydrolase) from Russell's viper venom.

Fractionation of Russell's viper venom revealed separate phosphohydrolase activities directed against p-nitrophenyl phosphate, bis(p-nitrophenyl) phosphate, p-nitrophenylthymidylic acid, and O,O-diethyl p-nitrophenyl phosphate (paraoxon). On gel fractionation, the first two activities are eluted ahead of the latter. They could be resolved further by phosphocellulose cation exchange chromatography. The hydrolytic activities directed against p-nitrophenylthymidylic acid hydrolyzing component is heat labile, while the paraoxon hydrolyzing component manifests an unusually high degree of heat stability. Gel filtration yields 9600 for the molecular weight of the "paraoxonase". This enzyme, as all known enzymes of this type, requires the presence of a divalent cation. Maximum activity is obtained in the presence of Ca2+. In the presence of Sr2+ the reaction rate is 50% of that of Ca2+; other divalent cations show lower activities. The presence of the enzyme is species specific. Of four species tested, only Russell's viper venom showed significant paraoxonase activity. Enzyme activity is intact following incubation with iodoacetate of p-chloromercuribenzoate. Activity is partially preserved even in the presence of 8 M urea.

4-Nitrophenylphosphatase↗

Mechanical ventilators as vehicles of infection.

Twenty-five patients from the intensive care unit who had been subjected to tracheostomy and require mechanical respiration were studied. Data are presented concerning the bacteriological controls performed on the tracheal exudates, various parts of the ventilators (Engström Model 200 and Bennett PR-2), and the Wright spirometer. The germs found were mainly pseudomonas, enterobacteriaceae germs and bacteria from the acinetobacter group. There was a high incidence of infection in the tracheostomies of these patients. We found a cause and effect relationship between the contaminating bacteria isolated from the cannula and the bacteria isolated from the tracheal exudates in the case of pseudomonas aeruginosa. However, this was not found to be the case where enterobacteriaceae were concerned. Acinetobacter calcoaceticus were isolated almost exclusively in the ventilators. The study calls attention to the need for rigorous disinfection of ventilators to prevent hospital cross infections.

Acinetobacter↗

Chronic experimental infection by Trypanosoma cruzi in Cebus apella monkeys.

Twenty young male Cebus apella monkeys were infected with CA1 Trypanosoma cruzi strain and reinfected with CA1 or Tulahuen T. cruzi strains, with different doses and parasite source. Subpatent parasitemia was usually demonstrated in acute and chronic phases. Patent parasitemia was evident in one monkey in the acute phase and in four of them in the chronic phase after re-inoculations with high doses of CA1 strain. Serological conversion was observed in all monkeys; titers were low, regardless of the methods used to investigate anti-T. cruzi specific antibodies. Higher titers were induced only when re-inoculations were performed with the virulent Tulahuén strain or high doses of CA1 strain. Clinical, electrocardiographic and ajmaline test evaluations did not reveal changes between infected and control monkeys. Histopathologically, cardiac lesions were always characterized by focal or multifocal mononuclear infiltrates and/or isolated fibrosis, as seen during the acute and chronic phases; neither amastigote nests nor active inflammation and fibrogenic processes characteristic of human acute and chronic myocarditis respectively, were observed. These morphological aspects more closely resemble those found in the "indeterminate phase" and contrast with the more diffuse and progressive pattern of the human chagasic chronic myocarditis. All monkeys survived and no mortality was observed.

Animals↗

Botulinum treatment of infantile esotropia with abduction nystagmus.

PURPOSE: To examine the effect of botulinum toxin type A (BTA) on the final correction of esotropia, A and V patterns, overaction of the oblique muscles, and dissociated vertical deviation (DVD) in infantile esotropia with nystagmus in abduction. METHODS: This retrospective study examined 54 patients treated with simultaneous bilateral medial injection of BTA. Subjects were divided into two groups: group 1 (first injection <18 months of age) and group 2 (first injection >18 months of age). RESULTS: Pre-BTA, group 1 patients had an angle of esotropia noticeably higher and fewer A patterns than group 2 patients. Post-BTA, group 2 received significantly fewer injections of BTA than group 1. The magnitude of the A patterns improved. Prior frequency of DVD increased significantly in group 1 (100%): 79% of DVD was decompensated compared with 47% in group 2. Overall success was obtained in 14% and 58% of groups 1 and 2, respectively. CONCLUSION: We do not support BTA treatment in infantile esotropia with nystagmus in abduction prior to age 18 months. After 18 months, the horizontal results are excellent and neither the incidence nor the degree of previous DVD are decompensated, resulting in high success rates for overall deviation and improving anisotropy in A.

Botulinum Toxins, Type A↗

[Trigeminal neuralgia in children as the only manifestation of Chiari I malformation].

OBJECTIVE: The appearance of trigeminal neuralgia in infancy is exceptional. Trigeminal neuralgia as the only manifestation of a Chiari malformation is also infrequent. We present the case of a patient with a Chiari type I malformation in which the only symptom was the presence of trigeminal neuralgia since infancy. We have found no similar cases in the literature. CLINICAL CASE: A 39 year old man with no significant clinical history complained of brief, recurrent episodes of pain in the right maxillary region, compatible with trigeminal neuralgia since the age of eight. The frequency, duration and intensity of these episodes had progressively increased. The only unusual finding on physical examination was a sluggish right corneal reflex. Cranial MR showed descent of the cerebellar tonsils to below the level of the posterior arch of the atlas, together with slight descent of the brainstem. These findings are characteristic of a Chiari type I malformation. The symptoms rapidly disappeared when treatment was started with carbamazepine. CONCLUSION: In exceptional cases, trigeminal neuralgia may present in infancy and be the only manifestation of a Chiari malformation.

Adult↗