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Biomedical subjects

L Romero

Publications and source records attributed to L Romero.

At least 55 records · Page 3Linked to original sources
PubMed1997

One-leg balance is an important predictor of injurious falls in older persons.

OBJECTIVE: To test the hypothesis that one-leg balance is a significant predictor of falls and injurious falls. DESIGN: Analysis of data from a longitudinal cohort study. SUBJECTS: Healthy, community-living volunteers older than age 60 enrolled in the Albuquerque Falls Study and followed for 3 years (N = 316; mean age 73 years). MAIN OUTCOME MEASURES: Falls and injurious falls detected via reports every other month. INDEPENDENT VARIABLES: Baseline measures of demographics, history, physical examination, Iowa Self Assessment Inventory, balance and gait assessment, and one-leg balance (ability to stand unassisted for 5 seconds on one leg). RESULTS: At baseline, 84.5% of subjects could perform one-leg balance. (Impairment was associated with older age and gait abnormalities.) Over the 3-year follow-up, 71% experienced a fall and 22% an injurious fall. The only independent significant predictor of all falls using logistic regression was age greater than 73. However, impaired one-leg balance was the only significant independent predictor of injurious falls (relative risk: 2.13; 95% CI: 1.04, 4.34; P = .03). CONCLUSION: One-leg balance appears to be a significant and easy-to-administer predictor of injurious falls, but not of all falls. In our study, it was the strongest individual predictor. However, no single factor seems to be accurate enough to be relied on as a sole predictor of fall risk or fall injury risk because so many diverse factors are involved in falling.

Accidental Falls↗
PubMed1996

The 5-HT1A antagonist WAY-100635 selectively potentiates the presynaptic effects of serotonergic antidepressants in rat brain.

The increases in extracellular serotonin (5-hydroxytryptamine; 5-HT) produced by some antidepressent drugs in forebrain are attenuated by the activation of somatodendritic 5-HT1A autoreceptors by the excess 5-HT induced by these agents in the midbrain raphe. Using microdialysis, we have examined the effects of the selective 5-HT1A antagonist WAY-100635 in rats pretreated with the selective 5-HT reuptake inhibitors (SSRIs) citalopram, fluoxetine, fluvoxamine, the tricyclic antidepressants clomipramine and desipramine and the monoamine oxidase inhibitor phenelzine. WAY-100635 markedly potentiated the increases in 5-HT produced by the SSRIs, clomipramine and phenelzine but it did not alter that produced by desipramine. These results indicate that the effects of serotonergic antidepressant drugs (but not those of desipramine, which mainly blocks noradrenaline reuptake) can be potentiated by 5-HT1A autoreceptor blockade.

Animals↗
PubMed1996

Effect of pindolol on the function of pre- and postsynaptic 5-HT1A receptors: in vivo microdialysis and electrophysiological studies in the rat brain.

In microdialysis studies, somatodendritic 5-HT1A receptors in the dorsal raphe nucleus (DRN) were activated by the local infusion of 50 microM citalopram, a selective 5-HT reuptake inhibitor (SSRI). This reduced extracellular 5-HT by about 50% in dorsal striatum, an area receiving 5-HT afferents exclusively from the DRN. (-)Pindolol dose-dependently attenuated this citalopram-induced reduction of striatal extracellular 5-HT. Consistent with its 5-HT reuptake blocking properties, single doses of the SSRI paroxetine (1 and 3 mg/kg IP) and citalopram (1 mg/kg IP) significantly elevated extracellular 5-HT in the dorsal striatum. Pretreatment with (-)pindolol (15 mg/kg IP) potentiated the effect of 3 mg/kg paroxetine and 1 mg/kg citalopram on striatal extracellular 5-HT. A 2-day treatment with 10 mg/kg/day (SC) of paroxetine reduced by 60% the spontaneous activity of 5-HT neurons of the DRN. However, 5-HT neurons displayed normal activity in rats treated with paroxetine and (-)pindolol for 2 days. The inhibitory effect of LSD on 5-HT neuronal firing activity was also markedly attenuated in (-)pindolol-treated rats, indicating that somatodendritic 5-HT1A receptors were blocked by (-)pindolol. To determine whether (-)pindolol also blocked postsynaptic 5-HT1A receptors in hippocampus, 5-HT and the prototypical 5-HT1A agonist 8-OH-DPAT were applied by microiontophoresis onto CA3 pyramidal neurons following the same treatment. (-)Pindolol did not modify the responsiveness of these neurons to 5-HT and 8-OH-DPAT. Taken together, these results indicate that (-)pindolol can potentiate the effects of an SSRI on extracellular 5-HT concentration by preventing the activation of somatodendritic 5-HT1A autoreceptors resulting from the blockade of the 5-HT transporter in the raphe. This presumably leads to enhanced 5-HT neurotransmission because (-)pindolol would not alter the responsiveness of certain postsynaptic 5-HT1A receptors, such as those located on hippocampal CA3 pyramidal neurons. These results provide a neurobiological basis for the reported potentiation of certain antidepressant drugs by pindolol in major depression.

Animals↗
PubMed1996

Acceleration of the effect of selected antidepressant drugs in major depression by 5-HT1A antagonists.

At clinically relevant doses, selective serotonin (5-HT) reuptake inhibitors (SSRIs) and MAO inhibitors (MAOIs) increase the extracellular concentration of 5-HT in the midbrain raphé nuclei, thereby activating inhibitory somatodendritic 5-HT1A autoreceptors. Consequently, the firing activity of 5-HT neurons is reduced and the enhancement of extracellular 5-HT concentration in forebrain is dampened. Overriding this feedback by using antagonists of 5-HT1A autoreceptors permits SSRIs to produce a marked increase of extracellular 5-HT in the forebrain. Hence, combined treatment with an SSRI and a 5-HT1A antagonist increases the extracellular concentration of 5-HT more so than the former drug alone. The treatment of patients with major depression using an SSRI and pindolol, a 5-HT1A/ beta-adrenoceptor antagonist, markedly reduced the latency of the antidepressant response in previously untreated patients and induced a rapid improvement in treatment-resistant patients.

Antidepressive Agents↗
PubMed1996

Associations of fat and muscle masses with bone mineral in elderly men and women.

Associations of fat and muscle masses with bone mineral status were studied in 301 men and women aged > or = 65 y. Bone mineral and soft tissue composition were estimated by using dual-energy X-ray absorptiometry. Univariate correlations suggested that muscle is associated more closely than fat with bone mineral content (BMC) as well as with bone mineral density (BMD) in men. In women, however, correlations of BMC with muscle were only slightly greater than those with fat and correlations with BMD were consistently greater with fat than with muscle. This suggests that correlations of BMC with muscle are influenced by bone and body size, especially in women. A multiple-regression model was developed that adjusts BMC for bone area, knee height, age, and the independent effects of fat and muscle. In men, muscle remained more closely associated with adjusted BMC than with fat. In women, fat mass was associated significantly with BMC but muscle mass was not. The exception was for women taking estrogen, in whom neither fat nor muscle was associated significantly with adjusted BMC. This study suggests that body fatness may be more important than muscle in maintaining bone mineral in elderly women not taking estrogen.

Absorptiometry, Photon↗
PubMed1996

Serum albumin is associated with skeletal muscle in elderly men and women.

Serum albumin concentrations decrease with age and values < 38 g/L are associated with increased morbidity, mortality, and disability in the elderly. It is not clear to what extent the decreases are associated independently with changes in metabolism, dietary intake, physical activity, morbidity, or body composition. We examined associations of serum albumin with age, protein and energy intakes, physical activity, morbidity, and muscle mass in 275 men and women aged 60-95 y. Serum albumin was measured with the bromcresol green procedure. Usual dietary intake and physical activity were quantified through questionnaires. Morbidity was ascertained from medical history, questionnaire, and examination. Muscle mass was estimated from dual-energy X-ray absorptiometry. In multivariate analyses, serum albumin was associated significantly with muscle mass after age, protein intake, physical activity, and comorbidity were controlled for in men and women. This study suggests that decreases with age in serum albumin concentrations are associated with muscle loss (sarcopenia) in the elderly. This association is independent of other factors that may affect muscle mass and albumin concentration. We suggest that the increased risk of disability with low serum albumin concentrations observed in the elderly may actually reflect an association with sarcopenia.

Aged↗
PubMed1996

A novel locus for non-syndromic sensorineural deafness (DFN6) maps to chromosome Xp22.

Non-syndromic X-linked deafness is highly heterogeneous. At least five different clinical forms have been described, but only two loci have been mapped. Here we report a Spanish family affected by a previously undescribed X-linked form of hearing impairment. Deafness is non-syndromic, sensorineural, and progressive. In affected males, the auditory impairment is first detected at school age, affecting mainly the high frequencies. Later it evolves to become severe to profound, involving all frequencies for adulthood. Carrier females manifest a moderate hearing impairment in the high frequencies, with the onset delayed to the fourth decade of life. Deafness was assumed to be X-linked dominant, with incomplete penetrance and variable expressivity in carrier females. The family was genotyped for a set of microsatellite markers evenly spaced at intervals of about 10 cM. We found evidence of linkage to markers in the Xp22 region (maximum lod score of 5.30 at theta = 0.000 for DXS8036 and for DXS8022). The position of the novel deafness locus (DFN6) was refined by haplotype analysis. Mapping of the breakpoints in two critical recombinants allowed us to define an interval for DFN6, delimited by DXS7108 on the distal side and by DXS7105 on the proximal side, and spanning a genetic distance of about 15 cM.

Audiometry, Pure-Tone↗
PubMed1996

Two actions are better than one: avoiding self-inhibition of serotonergic neurones enhances the effects of serotonin uptake inhibitors.

The serotonin (5-HT)-increasing action of 5-HT uptake or monoamine oxidase inhibitors is limited by a negative feedback at somatodendritic level. The excess 5-HT produced by these antidepressant drugs in the interstitial space of the midbrain raphe activates somatodendritic 5-HT1A autoreceptors, thereby attenuating terminal 5-HT release. This effect is maximal in forebrain areas innervated by the dorsal raphe nucleus and can be prevented by the administration of non-selective [(-)pindolol, (-)tertatolol] and selective (WAY-100635) 5-HT1A antagonists. In keeping with these observations, the combined administration of selective serotonin reuptake inhibitors (SSRIs) and 5-HT1A antagonists increase the cortical and striatal extracellular 5-HT concentration more than the former alone. Also, concurrent inhibition of the 5-HT and noradrenaline transporters with 20 mg/kg imipramine increases cortical extracellular 5-HT concentration more than SSRI doses which maximally block the 5-HT transporter. Moreover, the effects of fluoxetine on frontal cortex 5-HT are potentiated by a dose of desipramine that does not modify extracellular 5-HT by itself. Given the relevance of increased serotonergic transmission in the treatment of depression, these experimental data indicate that dual-action antidepressant treatments may be more effective than those which selectively inhibit the 5-HT transporter.

Animals↗
PubMed1996

[Hyponatremia as a complication of laparoscopic hysterectomy. Report of a case].

The case of a 42 years old woman, who had laparoscopic hysterectomy and seven hours after presented with a convulsive crisis and later a coma status, secondary to hyponatremia. Hyponatremia causes, are discussed, as well as its relationship with syndrome of inadequate secretion of antidiuretic hormone, diagnosis, management, prognosis factors and risk.

Adult↗
PubMed1995

[Adenosquamous carcinoma of minor salivary glands. Reporting a case in the tongue].

Adenosquamous carcinoma of the salivary glands is an unusual neoplasm not unanimously included in many classifications of salivary gland malignancies. A case sited in the oral cavity, within the tongue is reported. Clinical and histopathologic features are described together with a discussion about treatment and behaviour. We also include an updated of literature relating to this entity.

Carcinoma, Adenosquamous↗
PubMed1994

Reduction of in vivo striatal 5-hydroxytryptamine release by 8-OH-DPAT after inactivation of Gi/G(o) proteins in dorsal raphe nucleus.

5-HT1A receptor agonists reduce firing-dependent terminal 5-HT synthesis and release by activating somatodendritic 5-HT1A receptors. We have examined the effects of 8-hydroxy-2-(di-n- propylamino)tetralin (8-OH-DPAT, 0.1 mg/kg s.c.) on in vivo striatal 5-HT release in conscious rats with somatodendritic 5-HT1A receptors inactivated by the application of pertussis toxin in the dorsal raphe nucleus. The uncoupling of 5-HT1A receptors from hyperpolarizing potassium channels was demonstrated by the inability of the intra-raphe application of citalopram to reduce striatal release (control animals had a 47% reduction, an effect prevented by previous treatment with the 5-HT1A antagonist (-)-tertatolol). Yet 8-OH-DPAT (0.1 mg/kg s.c.) decreased striatal 5-HT release by 66% (peak effect) in pertussis toxin-treated rats, a value comparable to that found in naive animals (74%). This raises the possibility that other 8-OH-DPAT-sensitive serotonergic receptors different from 5-HT1A autoreceptors may be involved in the control of terminal 5-HT release.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Primary adenocarcinoma of the duodenum: management and survival in 67 patients.

BACKGROUND: Because of the rarity of primary adenocarcinoma of the duodenum, accumulation of natural history data has been difficult. As a result, debate continues over important treatment issues. METHODS: We did a retrospective review of 67 patients with nonampullary adenocarcinoma of the duodenum treated at the University of Texas M.D. Anderson Cancer Center between 1967 and 1991. Presenting symptoms and signs, diagnostic studies, operation performed, surgical pathology, and survival were analyzed. RESULTS: A primary duodenal tumor was demonstrated by upper gastrointestinal radiographs (UGI) in 37 of 42 patients (88%), esophagogastroduodenoscopy (EGD) in 49 of 55 (89%), and computerized tomograms (CT) in 21 of 42 (50%). A curative resection was performed in 36 of the 59 patients who underwent operation (61%); 27 had pancreaticoduodenectomies and nine had wide local excisions. Overall 5-year survival was 29%. The 5-year survival difference between resected and unresected patients was 54% versus 0%, respectively (p < 0.0001). No survival difference was noted between patients who underwent pancreaticoduodenectomy rather than wide local excision. Lymph node metastases were significantly related to the occurrence of distant metastases (p = 0.0034). The 5-year survival for patients with stage I or II tumors was 100% and 52%, respectively, compared to 45% and 0% for stage III and IV (p < 0.0001). CONCLUSIONS: Our data suggest that UGI and EGD are effective for diagnosing duodenal carcinoma. Survival is improved by curative resection and is not compromised by a wide local excision instead of a pancreaticoduodenectomy for lesions of the third and fourth portion. We recommend that adjuvant chemotherapy be considered for stage III disease, because distant failure is the predominant pattern of failure in this group.

Adenocarcinoma↗
PubMed1994

[Laparoscopic hysterectomy. Initial experience].

The results of the first twelve cases of Laparoscopic Assisted Vaginal Hysterectomy, are presented. The indications for hysterectomy were myomatosis, suspicion of adenomyosis and endometriosis. The surgical technique is described in detail in which a combination of bipolar Kleppinger forceps and reusable scissors were employed. There were two intraoperative accidents. One subcutaneous emphysema of the left half of the abdominal wall, thorax, neck, face and upper limb. The second case was a damage to a branch of the left epigastric artery. The average time was 4 hours 31 minutes which includes 9 patients to which another surgical procedure was practiced. There was no significant bleeding in any of the patients. The postoperative complications were 1 hyponatremia that needed the use of an Intensive Care Unit and the other was periumbilical hematoma of 3 cm. of diameter. The patient was discharged on the one to three postoperative day with an average of two days. The average hospital fee was 35% higher than an abdominal hysterectomy. All the surgery were videotaped and later viewed by the patients. It was concluded that the laparoscopic assistance that is offered to the vaginal hysterectomy is particularly advantageous for hysterectomy especially in the cases where absence of genital prolapse, when uni or bilateral Adnexectomy is required, previous past history of abdomino-pelvic surgery, endometriosis and adhesions. This procedure should be included in the armamentarium of the Gynecological Surgeons but only after and appropriate training.

Adenoma↗
PubMed1993

Effects of prolactin on explant cultures of rat ventral prostate: morphological and immunohistochemical study.

Specimens derived from rat ventral prostate were cultured by an explant culture technique using differents concentrations of ovine prolactin. Sacrificed explants embedded on paraffin were sectioned for morphologic and immunocytochemical studies using antibodies against prostatic acid phosphatase, prostatic specific antigen, and wide-spectrum monoclonal keratin. Prolactin significantly stimulated the growth of these cells in the concentration range of 1 x 10(-2) ui/ml, but was inhibitory at a concentration of 1 and 0.1 ui/ml. The 1 x 10(-3) and 1 x 10(-4) ui/ml prolactin concentrations demonstrated the preservation of a glandular epithelium with a columnar shape, similar to the normal appearance of ventral prostate from rats.

Acid Phosphatase↗