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Biomedical subjects

M Jaime

Publications and source records attributed to M Jaime.

24 records · Page 2Linked to original sources

Biomodulation of Fluorouracil in colorectal cancer.

5-Fluorouracil (5-FU) remains the agent of choice for the treatment of colorectal cancer. Research has focused on the biomodulation of 5-FU in order to attempt to improve the cytotoxity and therapeutic effectiveness of this drug in the treatment of advanced colorectal cancer. Modulation of 5-FU by methotrexate (MTX), trimetrexate (TMTX), interferon-alpha (IFN-alpha), leucovorin (LV), or N-(phosphonacetyl)-L-asparte acid (PALA) has produced higher response rates than those observed with 5-FU alone. Methotrexate may improve the durability of response to or survival with 5-FU, but with inferior results compared with those in trials of 5-FU and leucovorin. Trimetrexate produces a number of responses, and further phase III trials are in progress to confirm the results of promising phase II trials with this drug. IFN-alpha has shown therapeutic efficiency when combined with 5-FU alone or with 5-FU and leucovorin, but latest studies with these combinations have shown increased toxicity. Initial single-institution phase I trials with 5-FU and PALA reported promising responses, but the latter responses with PALA were not substantiated in randomized multicenter trials. Leucovorin enhances the cytotoxic activity of 5-FU in vitro and in vivo, and several clinical trials have shown improved response rates and possible trends in improved survival when such therapy is compared with the use of 5-FU as a single-agent. More recent randomized trials have focused their attention on determining the optimal dose and schedule with this combination for producing a better clinical response with minimal toxicity. Schedules using infusional 5-FU appear to be the most active regimens when 5-FU is used as a single agent, as demonstrated by recent randomized trials. The Southwest Oncology Group (SWOG) and the Eastern Cooperative Oncology Group (ECOG) have performed separate randomized trials and have shown that the optimal regimens employ infusional 5-FU as a single agent, and that these are the least toxic regimens, perhaps more effective, and associated with a better quality of life. Future studies will focus on infusional regimens involving either short-term, high-dose protracted or long-term, low-dose protracted infusion of 5-FU, since these regimens have shown the most favorable toxicity spectrum and produced the longest survival times. Future research will also focus on the evaluation of various methods of delivery of 5-FU, including oral administration of the drug in combination with compounds that can modify its catabolism.

Antimetabolites, Antineoplastic↗

Screening for ampicillin resistant Hemophilus influenzae and penicillin resistant Streptococcus Pneumoniae in healthy carriers.

800 samples of pharyngeal exudate were taken from healthy children and 28 healthy intrafamilial contacts of children with meningitis caused by H. influenzae type b. H. influenzae type be was isolated in 8.7 per cent of nursery children, H. influenzae type e in 0.12 per cent and non typifiable H. influenzae in 5.8 per cent. On intrafamilial contacts, 32 per cent had H. influenzae type b and non typifiable in 3.5 per cent. Percent age of ampicillin resistant H. influenzae type b was 14 per cent. No strains were found resistant to chloramphenicol. S. pneumoniae was isolated in 37 per cent of pharyngeal exudate samples. 25.5 per cent of strains tested were penicillin sensitive; 74.5 per cent has a decrease sensitivity. Based on these results we consider chloramphenicol to the the first drug of choice for treatment of severe H. influenzae infections and penicillin for S. pneumoniae infections recommending in the latter higher doses when dealing with central nervous system infections.

Ampicillin↗

New nuclear functions for calmodulin.

The data reported here summarize a series of results which reveal new functions for nuclear calmodulin (CaM). The addition of CaM inhibitors to cultures of proliferating NRK cells blocked the activity of the cyclin-dependent protein kinases 4 (cdk4) and 2 (cdk2), which are enzymes implicated in the progression of G1 and in the onset of DNA replication, respectively. CaM modulates the activity of cdk4 by regulating the nuclear location of both cdk4 and cyclin D, its associated regulatory subunit. By using CaM-affinity chromatography, we have recently identified two new nuclear CaM-binding proteins: (i) the protein La/SSB, which is an autoantigen implicated in several autoimmune diseases such as lupus erythematosus and Sjögren's syndrome (since La/SSB participates in the process of transcription mediated by RNA polymerase III, CaM could be involved in the regulation of this process); and (ii) the protein SAP145, a member of the spliceosome-associated proteins (SAPs) which is a subunit of the splicing factor SF3(b). This finding suggests the involvement of CaM in pre-mRNA splicing. Finally, a screening for new CaM-binding proteins in the fission yeast performed by using the phage display analysis, revealed that several nucleolar-ribosomal proteins associate to CaM, suggesting that CaM modulates ribosomal assembly and/or function.

Animals↗

[Haemophilus influenzae sensitivity to ampicillin and chloramphenicol in children in Mexico City].

The sensitivity to chloramphenicol and ampicillin of 127 strains of H. influenzae was tested. One hundred and one strains were obtained from the pharyngeal exudate of 828 healthy carriers under 5 years of age and 26 from the spinal fluid of children with meningoencephalitis. Sixty per cent of isolations corresponded to type b; 40 per cent were non typical and we only identified one type e. All H. influenzae obtained from spinal fluid corresponded to type b. The frequency of healthy carriers was greater in intrafamily contacts of children with H. influenza meningoencephalitis (p less than 0.01). Percentages of resistance to ampicillin varied between 6 and 23% for the different groups; we found no statistical difference among them (p less than 0.2). The prevalence of H. influenza resistant to ampicillin in the population studied was 1.2% for type b strains and 0.2% for non typical bacteria. Fourteen per cent of penicillin resistant type b strains were identified; all 127 isolations were to chloramphenicol; therefore, we recommend this drug instead of ampicillin for the treatment of H. influenza infections, with the exception of acute otitis media.

Ampicillin↗

[Repercussions of nursing activities on the intracranial pressure in patients with intracranial hypertension of traumatic or non-traumatic origin].

We study, in a prospective and randomized way, the influence existing between nursing maneuvers (suctioning, bathing and turning) and Intracranial Pressure (ICP) in patients diagnosed of Intracranial Hypertension Syndrome (ICHT). The study includes 22 patients admitted in Intensive Care at Hospital Universitario San Carlos (HUSC), during one year. All the patients had ICHT of traumatic or non traumatic origin. ICP was monitorized in every one through an intraventricular catheter and was over 20 Hg mm at admission or during 24 first hours of evolution. Doubt to the repercussion that the ICP values have on clinical evolutions we conclude that the nurse has to respond in an efficient, early and autonomous way in order to avoid uncontrolled elevation of ICP values during habitual management of patient.

Aged↗