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Biomedical subjects

F López

Publications and source records attributed to F López.

At least 55 records · Page 3Linked to original sources
PubMed1999

Epidemiological analysis of sequential Pseudomonas aeruginosa isolates from chronic bronchiectasis patients without cystic fibrosis.

PCR fingerprinting was used for the epidemiological investigation of 64 Pseudomonas aeruginosa isolates collected from 16 chronic bronchiectasis patients without cystic fibrosis: 56% of the patients harbored one clone, 12.5% carried a single major type with minor variants, and 31.5% carried two clones. Only a minority of the acquisitions of antibiotic resistance was related to the acquisition of exogenous strains. Mucoid and nonmucoid sets of isolates did not display any consistent differences in their patterns. The genetic similarity among the clones ranged from 10 to 69%. Cross-infection or common-source exposure did not appear to have occurred.

Bronchiectasis↗
PubMed1999

Changes in the expression of neurohypophyseal prolactins during the estrous cycle and after estrogen treatment.

Estrogens are recognized regulators of the expression of neurohypophyseal hormones and of anterior pituitary prolactin (PRL). Here we have investigated whether the levels of PRL mRNA and of 23 and 14 kDa PRL variants present in the hypothalamo-neurohypophyseal system change during the estrous cycle or in response to estrogen treatment. The reverse transcription polymerase chain reaction (RT-PCR) was performed to examine PRL mRNA expression in isolated paraventricular (PVN) and supraoptic (SON) hypothalamic nuclei. In both nuclei PRL mRNA levels appeared higher in cycling females than in male rats, with the highest level occurring at estrus. This increase may involve estrogen action, since estrogen administration to ovariectomized rats was associated with apparently higher PRL mRNA levels in both the PVN and SON. Expression of the PRL gene at these sites may occur via both transcriptional factor Pit-1-dependent and -independent mechanisms. RT-PCR detected the mRNA for Pit-1 in the PVN but only at estrus. The concentration of the 23 kDa immunoreactive PRL determined in the neurohypophysis was significantly higher during estrus and after estrogen treatment. However, no difference was detected in the levels of the neurohypophyseal 14 kDa PRL-like fragment along the estrous cycle nor after estrogen administration. This lack of parallelism between neurohypophyseal PRLs could relate to an estrogen-induced inhibition of the proteolysis of 23 kDa PRL at this site, since estrogen treatment reduced the activity of neurohypophyseal proteolytic enzymes able to cleave PRL. Altogether our results are consistent with estrogens having a stimulatory effect on PRL gene expression in the hypothalamo-neurohypophyseal system and a concomitant inhibitory action on PRL proteolysis at this site.

Animals↗
PubMed1999

[Predisposition to in vitro oxidation of LDL isolated from hypercholesterolemic patients. Interaction with arterial proteoglycans].

It is very well documented that cholesterol of the atherosclerotic plaques comes from LDL plasma particles and also a positive correlation between LDL plasma level and intensity of atherosclerotic lesions has been shown. Recent findings have revealed a direct relationship among arterial tissue atherogenic response and polyunsaturated fatty acids oxidation. The oxidized fatty acids within the low density lipoproteins makes these particles more atherogenic. In the present study the susceptibility of low density lipoprotein isolated from hypercholesterolemic patients to become oxidatively modified in vitro was investigated. The results show that the predisposition of hypercholesterolemic patients LDL to oxidation is fourfold increased, expressed in TBARS content (p < 0.0001) as compared to control LDL. Furthermore, the interactions of LDL with arterial proteoglycans apparently contribute to the accumulation of apo-B lipoproteins in atherogenesis. The hypercholesterolemic patients LDL shows higher values of proteoglycans-insolubilized LDL than LDL from controls.

Adult↗
PubMed1999

[Colorectal neoplasms. Treatment of obstruction with autoexpanding metal stents].

BACKGROUND: Expandable metal stents can be used as a palliative or pre surgical method to decompress obstructing colonic carcinomas. AIM: To assess the effectiveness of these stents in the treatment of obstructive colonic carcinoma. PATIENTS AND METHODS: Expandable metal stents were placed in nine patients with the diagnosis of colorectal carcinoma and with clinical and radiographic signs of intestinal obstruction. Stents were placed under fluoroscopic guidance in nine patients and with endoscopic help in 2. The indications were palliative treatment in 7 and pre surgical decompression in 2 patients. RESULTS: Stent placement was successful in all patients. One patient presented a self limited rectal bleeding after the procedure. Obstruction was relieved in less than 24 hours after the procedure. CONCLUSION: Expandable metal stent placement is an effective means of relieving intestinal obstruction caused by colorectal carcinoma.

Aged↗
PubMed1998

Effect of butanedione monoxime on the contractility of guinea pig ileum and on the electrophysiological activity of myenteric S-type neurones.

2,3-Butanedione monoxime (BDM) has demonstrated protective effects on isolated cardiac tissues, and on smooth muscle but its mechanism of action is not fully understood. To simultaneously study the effect of BDM on muscle contractility and on neuronal activity, the effect of BDM was tested in the contractile force of myenteric plexus-longitudinal muscle strips and in electrophysiological activity of myenteric S-type neurones of guinea pig ileum. BDM reduces, in a dose-dependent manner, the force of the spontaneous motility and the contractions induced by acetylcholine, bethanechol and electrical stimulation. The same BDM concentrations depolarize the neuronal membrane and reduce the rate of evoked firing. The effect of BDM can be attributed to a direct effect on the smooth muscle and to modifications of the neuronal activity.

Animals↗
PubMed1998

[Invasive fungal infections in patients with blood disorders].

BACKGROUND: Invasive fungal infections (IFI) are severe infectious complications frequently observed in patients with hematological disorders. The aims of this study were to analyse the characteristics of this particular type of infection in a large series of a single institution and to determine the factors associated with the outcome and therapeutic response. PATIENTS AND METHODS: This study reviews the clinical and microbiological features of 155 IFI occurred among 144 patients with hematologic disorders throughout a period of 17 years in a single institution. RESULTS: In 118 cases (82%) the diagnosis was acute leukemia. The main risk factors for developing IFI included a persistent and profound granulocytopenia, the use of broad-spectrum antibacterial agents, indwelling central venous catheters and the damage of normal host barriers following intensive cytotoxic chemotherapy. Candida (65 cases [44%]) and Aspergillus (38 cases [26%]) species were the most common fungal species isolated. An increasing number of IFI were caused by fungi previously considered as contaminants or harmless colonizers. The outcome of IFI was favourable in 78 cases (50%). The most important prognostic factors for the outcome of the IFI were the phase of cytotoxic chemotherapy (p = 0.005), the response of the underlying disease to the cytotoxic chemotherapy (p < 0.00001), and the recovery of neutropenia during the infection course (p < 0.00001). An earlier use of empirical antifungal therapy was also associated with a better outcome. CONCLUSIONS: In spite of earlier treatment and regardless the development of new antifungal agents, the prognosis of IFI in patients with hematological malignancies remains poor. The use of hematopoietic growth factors, through their impact in the duration and severity of neutropenia, may prove valuable the management of IFI in this setting.

Acute Disease↗
PubMed1998

Anal endosonographic evaluation after closed lateral subcutaneous sphincterotomy.

PURPOSE: The present study was undertaken to evaluate anal endosonographic results of the transverse and longitudinal extent of internal anal sphincter division after closed lateral subcutaneous sphincterotomy and its relationship to outcome with respect to anal fissure recurrence and postoperative anal incontinence. METHODS: Ten patients selected for symptomatic anal fissure recurrence (mean follow-up, 10.9 months) and 41 asymptomatic control patients (mean follow-up, 15.5 months) were reviewed by anal endosonography after closed lateral subcutaneous sphincterotomy. Clinical evaluation was focused on anal fissure recurrence and postoperative anal incontinence. The anal endosonographic study involves serial radial images of the distal, proximal, and midanal canal. RESULTS: In 32 patients in whom a complete internal sphincter defect was identified, 31 (75.6 percent) were from the control group and only 1 patient (10 percent) was from the recurrence group (P < 0.001). In 19 patients, an incomplete internal sphincter defect was identified; 10 (24.4 percent) were from the control group (residual median size, 1.8 mm; contralateral, 2.5 mm) and 9 patients (90 percent) were from the recurrence group (P = 0.001; residual median size, 1.4 mm; contralateral, 2.2 mm). Ten patients (19.6 percent) were incontinent for gas and three patients (5.9 percent) for liquid feces, without significant differences between groups. CONCLUSIONS: Anal endosonography is a useful method for evaluating the anatomic effectiveness of closed lateral subcutaneous sphincterotomy. An incomplete sphincterotomy is associated with significant symptomatic anal fissure recurrence.

Adult↗
PubMed1998

Pathologic rupture of the spleen as the initial manifestation in acute lymphoblastic leukemia.

Pathologic splenic rupture is a rare and life-threatening complication of acute leukemia. It is even more uncommon as the initial manifestation, and only a few cases has been reported in the literature. Early recognition of this complication is vital because the prognosis is fatal without immediate treatment by splenectomy. We report the case of a spontaneous spleen rupture irreversibly complicating the onset of acute lymphoblastic leukemia in a 19-year-old man, in spite of splenectomy. In our case abdominal ultrasound was a good, non-invasive diagnostic test. Therefore, we believe that the course of the underlying disease and the physical condition of the patient dramatically influenced the disease evolution.

Abdominal Pain↗
PubMed1997

Disc protrusion in the child. Particular features and comparison with neoplasms.

Lumbar intervertebral disc herniation, although common in adults, is infrequent in the young, and especially in patients under 17 years old. In this work we review clinical data pertaining to two pediatric groups of patients whose main complaint was low back pain and/or sciatica, trying to identify factors that might contribute to their earlier referral and to the differential diagnosis of protruded disc and spinal neoplasm in this population. Group A comprises 17 youngsters diagnosed as having lumbar herniated nucleus pulposus and group B, 16 children with neoplasms of the lower thoracic and lumbosacral regions. Both groups were similar in sex distribution and symptoms of pain and numbness. However, there was a striking difference in age at presentation. No patient in group A was younger than 11 years, while most of those in group B were in their first decade of life (P = 0.018). The classic clinical onset in the children with herniated discs started with low back pain and sciatica, as in the children with neoplasms, although in subgroup B leg pain tended to be bilateral. The usual examination findings in both groups were spinal rigidity and sensory loss, but motor weakness and impaired reflexes were found to be more frequent in the group with spinal growths (P = 0.02). Children with lumbosacral neoplasms also tended to present with atypical symptoms (acute onset, intracranial hypertension, subarachnoid hemorrhage and abdominal pain), while this was the exception in the group with herniated discs. Plain radiographs of the pediatric spine showed that X-ray examination is still a good tool for diagnosing spinal growths compared with their scant utility in disc herniations (P = 0.001). During the survey we were impressed by the children's apparent good tolerance to pain, which is probably due to the lack of the emotional component of pain in adults and explains their delayed referral for neurosurgical consultation. However, all modalities of treatment seemed to be effective in children, chemonucleolysis and surgery being extraordinarily effective in this age group. Accordingly, we see no reason for long-term conservative therapy in children with lumbar and sciatic pain; on the contrary, we believe these patients should be offered earlier neurosurgical treatment.

Adolescent↗
PubMed1997

Iatrogenic intradiploic meningoencephalocele. Case report.

The authors present the case of a 6-year-old girl who developed a right frontal intradiploic meningoencephalocele following an accidental dural tear produced during surgery for craniosynostosis. Although rare, growing skull fractures have been described in at least eight cases following the accidental laceration of the dura mater in the course of craniosynostosis repair. These cases closely resemble those produced by accidental trauma to the growing skull. However, the intradiploic location of a meningoencephalocele following surgery for craniosynostosis has not been documented previously. This patient presented with headache and a frontal tumor of bonelike consistency. Radiographs and computerized tomography scans of the skull revealed an intraosseous cyst, whereas magnetic resonance imaging demonstrated cerebral tissue herniation within the intradiploic tumor. Surgical treatment consisted of duraplasty and cranioplasty, which achieved good functional and cosmetic results. The pathogenesis of this unusual lesion is discussed and compared with the hypotheses advanced for explaining posttraumatic intradiploic cysts.

Child↗
PubMed1996

Determination of DDT and related compounds in blood samples from agricultural workers.

An analytical method combining a solid-phase (C18) clean-up and GC-electron-capture detection using a capillary column, was implemented to determine p,p'-DDT and its metabolites (p,p'-DDD and p,p'-DDE), as well as other organochlorine pesticides in whole blood samples from 30 farmers and 24 non-occupationally exposed workers. The average concentrations for the quantified pesticides, p,p'-DDT, p,p'-DDD and p,p'-DDE, were 0.9, 1.5 and 8.0 micrograms/l whole blood for exposed workers and 0.3, 0.5 and 3.3 micrograms/l for unexposed workers, respectively. GC-MS was used to confirm the identity of the pesticides found. Solid-phase extraction and the protocol used give a cleaner analytical matrix, not only improving sensitivity and resolution, but also allowing analyses with smaller blood samples as compared to other methods.

Agriculture↗
PubMed1996

Disseminated Blastoschizomyces capitatus infection in acute myeloblastic leukaemia. Report of three cases.

Three new cases of Blastoschizomyces capitatus infection occurring in neutropenic patients with acute myeloblastic leukaemia are reported. B. capitatus was isolated from blood cultures in all patients. All three patients were treated with amphotericin B, but only one was cured from the infection. Our study confirms the emergence of B. capitatus as an opportunistic agent of disseminated fungal infection in leukaemic patients.

Adult↗