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Biomedical subjects

H Ponce

Publications and source records attributed to H Ponce.

8 recordsLinked to original sources
PubMed2001

Galphimia glauca organic fraction antagonizes LTD(4)-induced contraction in guinea pig airways.

Galphimia glauca is used for the treatment of asthma and allergies in Latin American traditional medicine. The ethylacetate fraction from its aerial parts was assayed for bronchoconstriction induced by antigen and several agonists in guinea pig tracheae. The organic fraction significantly inhibited the contractile response to ovalbumin in tracheae from sensitized guinea pigs, and significantly and selectively inhibited the bronchoconstriction induced by leukotriene D(4) (LTD(4)). The relative potency of the ethylacetate fraction of G. glauca to produce a concentration-dependent rightward shift of LTD(4) concentration-response curve was similar to that reported for SK&F 104353, a well-known competitive LTD(4)-antagonist.

Animals↗
PubMed2000

Seizures induced by penicillin microinjections in the mesencephalic tegmentum.

The location and extension of a convulsive area in the brain stem in cats was determined through penicillin microinjections (0.5-1.0 microl) of a concentrated sodium penicillin solution (500 IU/microl), stereotactically oriented to multiple structures, in fully awake animals, partially restrained through a rod fixation system that avoided pain, allowed the observation of clinical seizures and simultaneous recording of EEG, EMG and multiple unit activity (MUA) from the injected site and the motor cortex (Cx). Clinical and EEG seizure patterns in relation to the injected sites and penicillin doses were studied in another group of animals using doses from 12.5 IU/0.1 microl to 125 IU/1.0 microl. The time relationship between muscular clonus, EEG spikes and MUA at the injected site and Cx were analyzed. The only area in which penicillin induced seizures was the mesencephalic tegmentum (MT). The amount of penicillin but not the stereotactic coordinates determined the seizure type. MT EEG and MUA paroxysms anticipated clinical seizure and Cx EEG spikes. When Cx EEG appeared, they were accompanied by an increase in MUA beginning in the Cx and EMG, followed by significant increase in MT MUA. The sequence of events suggest that MT seizure activity propagates via alternative pathways not involving direct reticulospinal or pyramidal tract pathways.

Animals↗
PubMed1996

The benefits of psychiatric hospitalization for older nursing home residents.

OBJECTIVE: To examine the demographic characteristics and treatment outcomes of nursing home residents admitted to a geropsychiatric inpatient unit. DESIGN: A retrospective cohort design based on an ongoing data base effort. SETTING: The geropsychiatric inpatient unit of the Houston Veterans Affairs Medical Center Hospital. PARTICIPANTS: All admissions to the unit from nursing homes during an 18-month period. MEASUREMENTS: Mini-Mental State Examination, Brief Psychiatric Rating Scale, Hamilton Rating Scale for Depression, Cohen-Mansfield Agitation Inventory, Rating Scale for Side Effects, and Global Assessment of Functioning were administered on admission and discharge. RESULTS: Paired t tests comparing change scores revealed significant decreases in general psychiatric symptoms (P < .001), depression (P < .001), and agitation (P < .001); significant improvement in global functioning (P < .001); with no significant changes in cognitive status (P = .485) or side effects (P = .120). When the patients were subgrouped according to reasons for admission, paired t tests revealed decreases in violence (CMAI Factor 1; P = .000), psychosis (BPRS thought disorder scale; P = .000 and hostility subscale; P < .008), and depression (HAM-D; P = .002). Four patients were discharged to less restrictive environments, all with chronic mental illnesses. CONCLUSION: Inpatient psychiatric hospitalization significantly benefits nursing home residents with and without dementia who are admitted for severe behavior problems.

Aged↗
PubMed1995

Vasorelaxant effect of the analgesic clonixin on rat aorta.

1. A novel vasorelaxant effect of clonixinate of L-lysine (Clx), analgesic and anti-inflammatory, was studied in rat aortic rings. 2. Clx completely relaxed aortic rings contracted by KCl 70 mM and together with its analog flunixin exhibited lesser potency but equal efficacy than verapamil. In comparison, indomethacin, which is a more potent cyclo-oxygenase inhibitor relaxed only about 40% of the maximal contraction of aortic rings. 3. Furthermore, Clx antagonized Ca2+ dependent aortic contraction and BAY K-8644 induced aortic contraction suggesting its calcium antagonist character. 4. From these results it can be concluded that the hypotensive effect seen in rats in vivo after Clx i.v. injection arises because of vasodilatory effect of Clx and gives further support to the proposal that the pharmacological mechanism of action of Clx should be calcium antagonism.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1984

Antagonistic effects of taurine and 4-aminopyridine on guinea pig ileum.

The effects of 4-aminopyridine (4-AP) and of taurine on the guinea pig ileum were examined. Four-AP increases the basal activity from 1.3 to 6.45 cm2/min. This effect is atropine-sensitive and calcium-dependent. Taurine counteracts the effects of 4-AP on muscle contracture in a concentration-dependent manner. In muscles preincubated with 20 mM taurine, the effect of 4-AP decreased about 65%. Taurine added at the time of maximal effect of 4-AP reduced the muscle contracture induced by the drug to the basal levels. Glycine and beta-alanine did not influence the contracture induced by 4-AP, whereas 25 mM gamma-aminobutyric acid (GABA) reduced it by 30%. Taurine reduced the basal muscle activity by 50% but did not affect the contracture induced by exogenously applied acetylcholine.

4-Aminopyridine↗