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Biomedical subjects

J R Salazar

Publications and source records attributed to J R Salazar.

13 recordsLinked to original sources
PubMed2001

Plant-growth inhibitory activity of cedrelanolide from Cedrela salvadorensis.

The effect of cedrelanolide, the most abundant limonoid isolated from Cedrela salvadorensis (Meliaceae), was assayed as a plant-growth inhibitory compound against monocotyledonous and dicotyledonous seeds. This compound inhibited germination, seed respiration, and seedling dry weights of some plant species (Lolium multiflorum, var. Hercules, Triticum vulgare, var. Salamanca, Physalis ixocarpa, and Trifolium alexandrinum). Our results indicate that cedrelanolide interferes with monocot preemergence properties, mainly energy metabolism of the seeds at the level of respiration. In addition, the compound inhibits photophosphorylation, H+ uptake, and noncyclic electron flow. This behavior might be responsible for its plant-growth inhibitory properties and its possible role as an allelopathic agent.

Fabaceae↗
PubMed1997

Intraarticular dexamethasone in advanced chronic synovitis in hemophilia.

From 1988 to 1966, 34 patients with advanced chronic hemophilic synovitis (25 Grade III and nine Grade IV) were treated with intraarticular injections of long acting dexamethasone (sodium phosphate of dexamethasone plus acetate of dexamethasone) in cycles of three injections with 3-week intervals between each injection with 6-month rest intervals between cycles for as many as three cycles, depending on the evolution of each case. All patients had chronic severe synovitis, axial deformity, muscular atrophy, and diminution of range of movement. There were 31 knees, two ankles, and two shoulders. Subjective and objective evaluations were done grouping the results in good, fair, and poor according to grade of patient satisfaction, presence of synovitis and pain, range of movement, and limitation of activities of daily living. In the subjective results there were 19 good results, 12 fair results, and four poor results, and in the objective evaluation there were 22 good results, nine fair results, and four poor results at an average followup of 1.5 years. The use of intraarticular dexamethasone as an alternative in the short to medium term for treatment of advanced chronic hemophilic synovitis with pain and limitation of function before doing an invasive surgical treatment is proposed.

Activities of Daily Living↗
PubMed1987

[Acute pancreatitis. Neurovascular and microcirculatory changes. Pathogenic and therapeutic study].

A group of 159 dogs divided in 8 sub-groups were studied, in regard to pancreatitis, the purpose of the study was to investigate the participation of the automatic nervous system in the course of acute pancreatitis. The procedures and the results were as follows: 1. Pancreatitis was induced in two forms: a) Injection of gallbladder bile, from the same animal to the pancreatic duct. b) Blind duodenal loop with exclusion of the distal duodenum through the pylorus. In both cases acute pancreatitis was obtained. Fat necrosis was predominant in type a, and hemorrhagic lesions in type b. 2. The anesthetic block of the celiac plexus controlled the pain and shock. The animals were in good general conditions but there were no changes in the pathological process of the pancreas. The same results were noted in surgical resections of splanchnic trunks. 3. When the surgical resections of splanchnic nerves was followed by a waiting period of 20 days from the production of pancreatitis there were no changes in the gland. 5. Vagotomy previous to pancreatitis does not have protector effects in the induction of pancreatitis. 6. Continuous perfusion of E.V. novocaine was of extreme utility. The animals remained without pain and the process remained stable when it was given in the initial face of edema. 7. The enzyme inhibitor (Trasylol) given in the first 24 hs. does not prove to be valuable. Due to the fermentative derangement the condition of the animals was better maintained in relation to the comparative animals.

Acute Disease↗
PubMed1983

Fetal scalp temperature during labor and its relation to acid-base balance and condition of the newborn.

Fetal scalp temperature and fetal-maternal temperature gradient were studied during well-established labor in a group of 97 patients using a technique that ensured at the same time the adhesion and the thermal insulation of the probe. In 78 infants with a one-minute Apgar score of 7 or above, a positive gradient of 0.2C was maintained throughout labor between the warmer fetal scalp temperature (37.3C) and the maternal rectal temperature. Periodic drops of temperature related to the uterine contractions occurred in only 43% of the cases. In a group of ten infants with a one-minute Apgar score of 6 or below, the fetal-maternal gradient was significantly different from this schema. There was an inversion of the gradient, the fetal scalp temperature becoming cooler (36.9C) than the maternal rectal temperature. The gradient was -0.2C at the beginning of the study and -0.5C 20 minutes before delivery. Periodic drops of temperature with uterine contractions were constant. In dead fetuses, fetal scalp temperature was much below that of the mother and this difference increased steadily until delivery. A good relationship was found between fetal-maternal gradient and the pH of the umbilical artery blood sampled at birth. When the mean gradient was 0.2C +/- 1 SD, pH averaged 7.27; in the group below 1 SD, mean pH was 7.19 (P less than .01).

Acid-Base Equilibrium↗
PubMedDate not supplied

Insect growth regulatory activity of some extracts and compounds from Parthenium argentatum on fall armyworm Spodoptera frugiperda.

The methanolic extract from aerial parts of Parthenium argentatum, afforded argentatin A and B. These compounds were evaluated for their effect on the fall armyworm (Spodoptera frugiperda). Toosendanin, a commercial insecticide derived from Melia azedarach was used as positive control. When tested for activity, using neonate larvae into the no-choice artificial diet bioassays, argentatin A, argentatin B and methanol extract caused significant growth inhibitory activity with GC50 of 17.8, 36.1 and 6.4 ppm at 7 days, respectively, and increased the development time of surviving larvae in a concentration-dependent manner with RGI values of 0.40, 0.60 and 0.26, at 25.0, 25.0 and 5.0 ppm, respectively. In addition, it was possible to observe in most of the treated groups a significant delay in the time of pupation, adult emergence and deformities. Acute toxicity against adults of S. frugiperda was also found, MeOH extract had the most potent activity with LD50 value of 3.10 ppm. In addition, MeOH extract and argentatin A caused acetylcholinesterase inhibition of 93.7% and 90.0%, at 5.0 and 50.0 ppm, respectively; whereas argentatin B had only slight inhibitory activity. Therefore, the MeOH extract was identified as insecticidal extract from P. argentatum with activity at concentrations above 15.0 ppm.

Acetylcholinesterase↗
PubMedDate not supplied

Acetylcholinesterase and insect growth inhibitory activities of Gutierrezia microcephala on fall armyworm Spodoptera frugiperda J.E. Smith.

From the aerial parts of Gutierrezia microcephala (Asteraceae), four oxyflavones were isolated, namely 5,7,2'-trihydroxy-3,6,8,4',5'-pentamethoxyflavone (1); 5,7,4'-trihydroxy-3,6,8-trimethoxyflavone (2); 5,7,2',4'-tetrahydroxy-3,6,8,5'-tetramethoxyflavone (3); 5,2'-dihydroxy-3,6,7,8,4',5'-hexamethoxyflavone (4), and an ent-clerodane, bacchabolivic acid (5). Compounds 1-5, the synthetic methyl ester (6), n-hexane and MeOH extracts were evaluated against the fall armyworm (Spodoptera frugiperda). Gedunin, a known insect growth regulator isolated from Cedrela spp. was used as a positive control. When tested for activity on neonate larvae into the no-choice artificial diet bioassay, flavone (1), clerodane (5), its methyl ester (6), MeOH and n-hexane extracts caused significant larval mortality with MC50 of 3.9, 10.7, 3.46, 7.95 and 7.5 ppm at 7 days, respectively, as well as growth reduction. They also increased the development time of surviving larvae and a significant delay in time to pupation and adult emergence. Acute toxicity against adults of S. frugiperda was also found, 5, 6, gedunin and n-hexane extract had the most potent activity with LD50 value of 6.59, 15.05, 10.78, and 12.79 ppm, respectively. In addition, MeOH, n-hexane extracts, 5, 6 and gedunin caused acetylcholinesterase inhibition with 93.7, 100, 90.2, 62.0 and 100% at 50.0 ppm, respectively; whereas 1-4 exhibited only moderate inhibitory activity. Compounds 1, 5 and 6 showed inhibitory activities comparable with gedunin. These compounds could be responsible of the insect growth inhibitory activity of this plant.

Acetylcholinesterase↗