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F Diaz

Publications and source records attributed to F Diaz.

At least 37 records · Page 2Linked to original sources
PubMed1999

Synthesis and hypolipidaemic evaluation of a series of alpha-asarone analogues related to clofibrate in mice.

A series of alpha-asarone analogues related to clofibrate, containing an acetic acid group at C-2 of the aromatic ring, has been prepared as the acids or as the ethyl and methyl esters. The corresponding alcohols were also synthesized by reduction of the ethyl esters. The compounds were examined in hyperlipidaemic male mice to evaluate their ability to modify serum lipoprotein cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides after oral administration of 40 and 80 mg kg(-1) for 6 days. Except for methyl 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetate at either dose, these clofibrate-related phenoxyacetic acid derivatives were found to have significant hypocholesterolaemic activity. Levels of low-density lipoprotein cholesterol and triglycerides were significantly reduced and those of high-density lipoprotein cholesterol were elevated. 2-Methoxy-5-nitro-4-(2-propenyl)phenoxyacetic acid was active at both doses in all the tests. Clofibrate (150 mg kg(-1)) was more potent at reducing low-density lipoprotein cholesterol. No activity was detected for the alcohol derivatives. These preliminary results suggest that this class of compound might have more promise as potential hypolipidaemic agents than other alpha-asarone derivatives. Further investigation and characterization should be performed to determine the mode of action of these agents on lipid metabolism.

Allylbenzene Derivatives↗
PubMed1998

Interactive image-guided surgical resection of intracranial arteriovenous malformations.

Surgical excision is the only treatment method that immediately prevents increased morbidity or mortality as a result of hemorrhage from arteriovenous malformations (AVMs). For those lesions located deep within the cerebral hemispheres or near eloquent areas, conventional surgical resection may be associated with an unacceptable degree of morbidity and mortality. Herein we report our experience in the resection of these lesions using interactive image guidance. There were five women and five men in the patient group. Their age ranged from 16 to 73 years (mean = 41). Clinical presentation included hemorrhage (n = 7), headaches (n = 2), and seizures (n = 1). All lesions were classified using the Spetzler-Martin grading system as follows: grade I (n = 4), grade II (n = 5), and grade III (n = 1). The locations of the lesions were supratentorial (9) and infratentorial (1). Surgical planning was carried out using the Neurological Surgery Planning System software developed at Wayne State University. An infrared-based system was used to locate and define the lesion intraoperatively. For those lesions located near or within eloquent areas, an awake craniotomy with functional mapping was carried out. Clinical follow-up ranged from 3 to 62 months (mean = 34). Complete surgical excision was achieved in all patients, which was demonstrated postoperatively by digital substraction angiography. The preoperative neurological status remained unchanged in seven patients and improved in three. There was no associated morbidity and mortality with this technique. Image-guided surgical resection of arteriovenous malformations represents a valuable technique, especially in small deep-seated lesions and in those near eloquent areas.

Adolescent↗
PubMed1998

Aspects of dysphoria and symptoms of schizophrenia.

BACKGROUND: In the past it has been postulated that dysphoric emotions may be related to positive and/or negative symptoms in schizophrenia. The results of several recent studies have suggested that composite dysphoria indices are more strongly related to positive than negative symptoms. In the current study we use part correlation techniques to examine the possible unique contributions of two aspects of dysphoria--depression and anxiety--to three syndromes of symptoms (reality distortion, disorganization and psychomotor poverty) within schizophrenia. METHODS: Data were obtained from 60 patients with a DSM-III-R diagnosis of schizophrenia. Symptoms of schizophrenia were assessed using the SAPS and SANS and dysphoria was assessed using both self-report (BDI and BAI) and observer ratings (HRSD and HARS). Assessment of schizophrenia symptoms and ratings of depression and anxiety were completed by different observers. In addition, drug induced extrapyramidal side effects were rated. RESULTS: Part correlations showed that unique aspects of anxiety (particularly physiological arousal) were correlated with reality distortion while unique aspects of depression (including psychomotor slowing and loss of social interest) were related to psychomotor poverty. At least part of the latter relationship may be due to extrapyramidal side effects of neuroleptic medication. CONCLUSIONS: Although there is considerable overlap between anxiety and depression, it appears that the unique arousing or activating aspects of anxiety are related to the experience of reality distortion symptoms in schizophrenia and the unique slowing and withdrawal aspects of depression are particularly related to psychomotor poverty. Possible reasons for these relationships are discussed.

Adult↗
PubMed1998

Interactive image guided surgery of the pineal region.

A wide variety of lesions occur in the pineal region. Of these, only 25% may benefit from surgical resection, being benign or radioresistant in nature. In the remaining 75% (malignant or radiosensitive), a conservative approach is preferred. Surgical resection of lesions arising from the pineal region has been associated with high morbidity and mortality, due to the complex microanatomy of this area. Recently computer-assisted surgery has emerged as an ideal method to safely approach many intracranial lesions. In the present study we discuss our experience in interactive image-guided surgical management of pineal mass lesions, in terms of patient selection, methodology, and surgical morbidity and mortality. From July 1992 to December 1996, 15 patients underwent interactive image guided surgical procedures. There were eight men and seven women. Age ranged from 5 to 79 years (mean 30). Preoperatively all patients underwent neuroimaging studies that included computed tomography and magnetic resonance imaging under stereotactic conditions. Surgical planning was carried out using the Neurological Surgical Planning System software developed at Wayne State University. In patients with a preoperative diagnosis of a malignant or radiosensitive lesion (n = 10), an interactive image-guided stereotactic biopsy was considered, whereas for those with benign or radioresistant lesions (n = 5) surgical excision using an infrared based system was carried out. Histological diagnosis was obtained in all patients. There was no morbidity and mortality associated with computer-assisted procedures for biopsies the diagnostic yield was 100%. For patients that underwent interactive image-guided surgery, gross total removal was accomplished in 3 and in 1 patient a subtotal resection greater than 90% was achieved. Interactive image-guided biopsy represents a safe and accurate method in the diagnosis of malignant and/or radiosensitive pineal lesions. Using this technique surgeons can simulate preoperatively the surgical trajectory, thus avoiding damage to critical and vascular structures. For patients with benign or radioresistant lesions, computer-assisted surgical excision is recommended.

Adolescent↗
PubMed1997

Sarcoidosis.

Explore the source record for details and available documents.

Arthritis↗
PubMed1997

Interactive image-guided resection of cerebral cavernous malformations.

Between July 1992, and February 1997, 15 patients with cavernous malformations underwent interactive image-guided resection of their lesions. There were eight women and seven men in the group, ranging in age from 6 years to 62 years (mean 34 years). Clinical presentations included seizures (n = 7), headache (n = 4), and hemorrhage (n = 4). Prior conventional subtotal resection had been performed in one patient, and a history of prior hemorrhage was found for two patients. Diagnosis was made using magnetic resonance imaging and digital substraction angiography. Locations of the lesions were temporal (n = 9), frontal (n = 3), thalamus (n = 1), basal ganglia (n = 1), and pons (n = 1). Size ranged from 9 to 20 mm (mean 12 mm). For those lesions located near or within eloquent areas (n = 7), an awake craniotomy with functional cortical and subcortical mapping was performed. An infrared system was used intraoperatively to confirm the location and the extent of the resection of these lesions in real time. In 1996 we started using a robotic microscope to aid in localization and resection. Clinical follow-up ranged from 2 to 54 months (mean 27 months). In all 15 patients, complete surgical resection was achieved as demonstrated by postoperative magnetic resonance imaging studies. Two patients had postoperative transient neurological deficits (13.3%) that cleared over a 6-month period. One of them had a lesion in the pons, with multiple cranial nerve deficits postoperatively that gradually improved. There was no associated mortality. Histological diagnosis was consistent with cavernous angioma in all cases. Clinical follow-up revealed that 13 patients experienced complete recovery from preoperative symptoms and two patients with seizures showed marked improvement. We conclude that interactive image-guided surgery for deep-seated cavernous malformations represents a very accurate and safe approach.

Adolescent↗
PubMed1997

Use of buccal fat pad to repair intraoral defects: review of 30 cases.

The buccal fat pad has been frequently used for the closure of oro-antral and oro-nasal communications. There are a few studies in the literature reporting its use in defects secondary to tumoral resections. In this paper we consider both the anatomical basis and the surgical technique. We also review 30 cases, used for the repair of 15 defects due to tumoral resections, 8 to maxillary cysts, 6 to communications and 1 secondary to a postraumatic defect. It has been successful in 28 of the 29 patients, with a complete epithelization of the flap, even in 4 cases with partial necrosis of the pad. It is an acceptable type of reconstruction, versatile and of a simple surgical technique. However, its use is limited to small or medium defects, being sometimes scarce.

Adenoma, Pleomorphic↗
PubMed1997

Neutral and acid mucins and eosinophil and argyrophil crystalloids in carcinoma and atypical adenomatous hyperplasia of the prostate.

Neutral and acid mucins and eosinophil and argyrophil crystalloids were studied in the glandular intraluminal contents of 130 prostatic carcinomas (PCa) and 22 atypical adenomatous hyperplasias (AAH). Specimens were studied in the usual extension for diagnostic purposes and considered positive when minimal amounts of mucin or any crystalloid were present. Some amount of altered secretion was seen in 110 PCa (84.6%) and in 17 AAH (77.3%); the similarity of the figures speaks for the close relationship of these lesions. The relative incidences in PCa/AAH were 61.5%/77.3% for neutral mucin, 80%/54.5% for acid mucin (p < 0.01), 25.4%/50% for eosinophil crystalloids (p < 0.02), 44.6%/9.1% for argyrophil crystalloids (p < 0.01) and 57%/36% for a compound secretion. The incidence of eosinophil crystalloids was greater in AAH and inversely proportional to the Gleason grade in PCa. The incidence of acid mucins and argyrophil crystalloids was higher in PCa and directly proportional to the tumour grade in all but the poorly differentiated ones. It is therefore suggested that AAH positive for acid mucins or argyrophil crystalloids be classified in the high grade AAH group.

Aged↗
PubMed1997

Urethral cultures in female patients with a spinal cord injury.

Quantitative cultures of the urethral meatus were obtained from women with SCI undergoing intermittent catheterization. When compared with the urethral cultures of a group of female subjects, women with SCI had a greater number of isolates of Klebsiella pneumonia and Pseudomonas aeruginosa in the urethral flora. However there was not a significantly greater number of isolates or log numbers of E. coli or Enterococcus sp. in the urethral flora. The E. coli and Enterococcus sp. isolated from the urine were not isolated from the urethra of female patients with SCI in one third of the patients. This poor correlation between the simultaneous urethral and urine cultures of female subjects with SCI may reflect colonization of the urine with organisms that were unable to adhere to the mucosa and colonize the urethra. To what extent these organisms colonize or are temporary residents may be important in the pathogenicity of the infection.

Adult↗
PubMed1997

Interactive image guidance in skull base surgery using an opto-electronic device.

The applicability of an image guidance frameless system based on an opto-electronic sensor device in skull base surgery was explored in this study. Five embalmed heads with external fiducial markers placed in noncoplanar points were scanned (CT scan) and different skull base approaches were reproduced in these specimens. The opto-electronic system is comprised of an infrared camera, a local rigid body, and a 24-light-emitting diode probe attached to different surgical instruments. DOS-based calibration and transformation software and Unix-based surgical planning software were also used. The anatomic landmarks identified during the dissection were matched with the corresponding points derived from computed tomographic (CT) scans. This information allowed the surgeon to develop a three-dimensional representation of the surgical field and to anticipate the next anatomic structure encountered during the dissection. This infrared device operated in real time, is not affected by external factors with regard to its accuracy, and does not interfere with standard neurosurgical techniques. This frameless system is helpful in minimizing the risk of morbidity and provides an accurate guide during the approach, as well as unobstructed access to the surgical field.

Journal Article↗
PubMed1997

Chronic atrophic gastritis: early diagnosis in a population where Helicobacter pylori infection is frequent.

Chronic atrophic gastritis (CAG) is a premalignant condition characterized by loss of gastric antral deep glands. The histologic changes in antral gastric biopsy specimens from 54 Peruvian patients with dyspepsia were studied to detail the development and characteristics of CAG. Ninety-six percent of the biopsies revealed severe superficial mucosal inflammation and 89% showed deep inflammation. Moderate or severe CAG was present in 36 (67%) of the 54 patients. In the early stages of CAG, a glandular lymphoid adherence lesion was noted in 17 (31%) of the 54 biopsy specimens. This lesion consisted of lymphocytes adherent to the antral deep gland cells and was associated with glandular epithelium alterations. The late stage was characterized by small glands, remnants of glands, and gland replacement with a fibrocellular infiltrate or intestinal metaplasia. We propose that the development of CAG probably proceeds via a stereotyped sequence, with an early deep inflammatory component that may trigger local gland destruction and eventual permanent loss.

Adolescent↗
PubMed1997

Radiosurgical treatment of meningiomas.

From January 1992 to November 1996, 17 patients with the diagnosis of intracranial meningioma underwent radiosurgical treatment. Of these, 7 patients were treated using a Linac-based system (group 1), and 10 using the Leksell Gamma Knife unit (group 2). The follow-up ranged between 12 and 48 (median 33) months for group 1 and between 1 and 11 (median 5) months for group 2, consisting of clinical and MRI assessments every 3 months during the first year, and every 6 months thereafter. There were 14 women and 3 men. The mean age was 42 years. Prior to radiosurgery, 15 patients underwent surgical procedures. Histological diagnosis was consistent with benign meningioma, except in 2 patients (malignant meningioma). In 15 patients with benign meningiomas there was no evidence of tumor growth as demonstrated by clinical and radiological evaluation, in 2 patients with a malignant histological type there was tumor progression.

Adult↗
PubMed1997

The effect of urethral introducer tip catheters on the incidence of urinary tract infection outcomes in spinal cord injured patients.

PURPOSE: We attempted to determine whether an introducer tip catheter reduces urinary tract infection in spinal cord injured patients on intermittent catheterization. MATERIALS AND METHODS: The introducer tip catheter bypasses the colonized 1.5 cm. of the distal urethra. Enrolled patients were prospectively entered into the study in alternate groups depending on whether they reflex voided: group 1--on intermittent catheterization with the introducer tip catheter but not voiding spontaneously or wearing an external urinary catheter, group 2--same as group 1 but using a nonintroducer tip catheter; group 3--on intermittent catheterization with the introducer tip catheter, voiding by reflex and wearing an external urinary catheter, and group 4--same as group 3 but using a nonintroducer tip catheter. RESULTS: Statistical significance was shown when comparing patients using versus not using the introducer tip catheter regardless of whether an external urinary catheter was worn (p = 0.0121). A greater difference was noted between patients using and not using the introducer tip catheter in the intermittent catheterization only group (p = 0.0093). CONCLUSIONS: The introducer tip catheter decreased urinary tract infections in hospitalized men with spinal cord injury on intermittent catheterization.

Adolescent↗
PubMed1996

A study of the interrelationship between and comparative interrater reliability of the SAPS, SANS and PANSS.

We assessed the comparative interrater reliability of the SANS/SAPS and PANSS as measures of symptomatology in schizophrenia and also examined the interrelationship between scores on these instruments. Two experienced raters used these Scales to assess positive and negative symptoms in a group of 85 patients with a DSM III-R diagnosis of schizophrenia. Ratings were based on structured clinical interviews, review of case notes and consultation with staff familiar with the patients. Comparable levels of interrater reliability were found for each system of measuring symptomatology, but levels of interrater reliability were on the whole lower than have been reported in the past. There were high correlations between overall indices of positive and negative symptomatology derived from the two measurement systems.

Adult↗
PubMed1996

Interaction of internal Ba2+ with a cloned Ca(2+)-dependent K+ (hslo) channel from smooth muscle.

We have studied potassium currents through a cloned Ca(2+)-dependent K+ channel (hslo) from human myometrium. Currents were recorded in inside-out macropatches from membranes of Xenopus laevis oocytes. In particular, the inactivation-like process that these channels show at high positive potentials was assessed in order to explore its molecular nature. This current inhibition conferred a bell shape to the current-voltage curves. The kinetic and voltage dependence of this process suggested the possibility of a Ba2+ block. There were the following similarities between the inactivation process observed at zero-added Ba2+ and the internal Ba2+ block of hslo channels: (a) in the steady state, the voltage dependence of the current inhibition observed at zero-added Ba2+ was the same as the voltage dependence of the Ba2+ block; (b) the time constant for recovery from current decay at zero-added Ba2+ was the same as the time constant for current recovery from Ba2+ blockade; and (c) current decay was largely suppressed in both cases by adding a Ba2+ chelator [(+)-18-crown-6-tetracarboxylic acid] to the internal solution. In our experimental conditions, we determined that the Kd for the complex chelator-Ba2+ is 1.6 x 10(-10) M. We conclude that the current decay observed at zero-added Ba2+ to the internal solution is due to contaminant Ba2+ present in our solutions (approximately 70 nM) and not to an intrinsic gating process. The Ba2+ blocking reaction in hslo channels is bimolecular. Ba2+ binds to a site (Kd = 0.36 +/- 0.05 mM at zero applied voltage) that senses 92 +/- 25% of the potential drop from the internal membrane surface.

Animals↗
PubMed1996

Renal infarction in a severely hypertensive patient with lupus erythematosus and antiphospholipid antibodies.

Systemic lupus erythematosus (SLE) patients, specially those with antiphospholipid antibodies, have a high incidence of arterial and venous thrombotic manifestations. However, renal infarction has been rarely reported in these patients. The case of a young female with renal infarction, diagnosed by renal arteriography and scintigraphy, and arterial hypertension (AH) is described. In subsequent years she also suffered several cerebrovascular accidents with important neurological sequelae. No evidence of systemic disease was observed at this time. Fourteen years after the renal infarction a diagnosis of SLE was established. Despite therapy with prednisone, acetylsalicylic acid, azathioprine and antihypertensive drugs the progression of the neurological disease led to death. The sudden appearance of severe AH in a young woman with a renal infarction should alert the clinician about a possible underlying renal artery thrombosis in association with SLE and antiphospholipid antibodies.

Adult↗
PubMed1996

Vascular malformations of the brain. Surgical management using interactive image guidance.

This article describes the use of interactive image guidance in the surgical management of vascular malformations (VMs). Indications include VMs located in or around eloquent brain regions such as speech and motor sensory areas. The image guidance provides a three-dimensional view of the actual vascular malformations through computer simulation and an accurate means of determining its position in relation to adjacent brain structures (anatomic localization).

Adolescent↗