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Biomedical subjects

E Gonzalez

Publications and source records attributed to E Gonzalez.

At least 73 records · Page 4Linked to original sources
PubMed1998

Genealogy of the CCR5 locus and chemokine system gene variants associated with altered rates of HIV-1 disease progression.

Allelic variants for the HIV-1 co-receptors chemokine receptor 5 (CCR5) and CCR2, as well as the ligand for the co-receptor CXCR4, stromal-derived factor (SDF-1), have been associated with a delay in disease progression. We began this study to test whether polymorphisms in the CCR5 regulatory regions influence the course of HIV-1 disease, as well as to examine the role of the previously identified allelic variants in 1,090 HIV-1 infected individuals. Here we describe the evolutionary relationships between the phenotypically important CCR5 alleles, define precisely the CCR5 regulatory sequences that are linked to the CCR5-delta32 and CCR2-641 polymorphisms, and identify genotypes associated with altered rates of HIV-1 disease progression. The disease-retarding effects of the CCR2-641 allele were found in African Americans but not in Caucasians, and the SDF1-3'A/3'A genotype was associated with an accelerated progression to death. In contrast, the CCR5-delta32 allele and a CCR5 promoter mutation with which it is tightly linked were associated with limited disease-retarding effects. Collectively, these findings draw attention to a complex array of genetic determinants in the HIV-host interplay.

Adolescent↗
PubMed1998

Determination of metal ions in algal solution samples by capillary electrophoresis.

Trace metals determination in aqueous samples can be readily accomplished by capillary electrophoresis (CE) via indirect absorbance detection. A method for the separation of metal ions is presented and applied to the determination of seven metals in algal solution samples. 2-Hydroxyisobutyric acid background electrolyte (BGE) containing UV CAT-1 (an ultraviolet-absorbing amine) is used to perform capillary ion analysis. Acetic acid is used to adjust the pH value of BGE to 4.4. All ions can be separated in less than 15 min. All peaks are well separated and baseline resolved (i.e., no peaks overlapped). This work presents the applicability of CE to the quantitative analysis of algal solution samples and shows the adsorption process of seven metals in solution (Mn, Cd, Cr, Ni, Zn, Pb, Cu) to Chlorella vulgaris. The innovation of the application of CE in the determination of metals bound by Chlorella vulgaris is shown to be an improvement of the pH over what has been published previously. The detection limit is in the range of 13 (Mn) to 102 (Pb) ppb with electrokinetic injection mode (15 kV, 7 s). Reproducibility was 1.4% for the migration time, better than 5% for peak area for four of the metal ions (Cr, Mn, Cd, and Cu), and lower than 5% for the other three (Ni, Zn, and Pb). Calibration curves are linear for most ions in the 10(-7)-10(-5)M range (correlation coefficient r2 = 0.9933-0.9986) using electrokinetic injection mode.

Cations↗
PubMed1998

Surgical and nonsurgical management of primary and metastatic liver tumors.

The medical records of 267 patients who had liver tumors, primary and metastatic, from 1988 to 1995 were retrospectively reviewed. Two hundred thirteen patients (80%) had metastatic disease, and 54 patients (20%) had primary liver disease. Their clinical manifestations and laboratory values were evaluated as factors predictive of diagnosis and survival. There was a significant increase in the occurrence of upper abdominal pain, weight loss, extrahepatic symptoms due to the metastatic origin, and hepatomegaly. Metastases from colorectal primary lesions were synchronous in 34 patients and metachronous in 31 patients. Stomach, lung, and pancreatic primaries were more commonly synchronous. Breast metastases were more commonly metachronous. Elevated serum glutamic-oxaloecetic transaminase and alkaline phosphatase and decreased albumin were the most common liver test abnormalities at diagnosis. Carcinoembryonic antigen values were elevated in the majority of colon cancer patients. Eighty-one percent of patients with primary liver cancer had elevated levels of alpha-fetoprotein, 40 per cent were seropositive for hepatitis B, and 23 per cent were seropositive for hepatitis C. Seventy-nine patients (30%) underwent surgery for their cancer, 37 (47%) had resections, 38 (48%) were unresectable, and 4 (5%) underwent liver transplantation. The patients who underwent surgery had a 32 per cent 5-year survival rate compared to a 0 per cent 5-year survival in the patients who did not have surgery (p = 0.0001). The patients who had resections had a better survival rate than those deemed unresectable at surgery (62% versus 0% at 5-years with p = 0.0008). The perioperative morbidity rate was 16 per cent, with lobectomies having the best rate and trisegmentectomies having the worst. Perioperative mortality rate was zero for all liver resections. Hepatic resection and, in selected patients, liver transplantation are the only two available therapeutic modalities that produce long-term survival with a possible cure in patients with primary and metastatic liver tumor.

Adolescent↗
PubMed1997

Assessment of continuous cold blood cardioplegia in coronary artery bypass grafting.

BACKGROUND: A method of cold blood cardioplegia (CBCP) delivered continuously and in a retrograde manner was compared with methods differing only by their rate (intermittent) or way (antegrade) of administration. METHODS: This study comprises 298 consecutive patients undergoing isolated coronary artery bypass grafting procedures performed by the same surgeon from 1992 to 1995. Three-vessel disease characterized 58.8% of the cases, and the left ventricular ejection fraction was less than 0.40 in 22.8%. In group I (n = 100), CBCP was administered in an antegrade and intermittent fashion; in group II (n = 87), CBCP was given in a retrograde and intermittent manner; in group III (n = 111), CBCP delivery was retrograde and continuous. RESULTS: The incidence of major cardiac adverse outcome (death or need for intraaortic balloon counterpulsation) was 7.0% in group I, 8.0% in group II, and 0.9% in group III (p = 0.040). Repeated-measures analysis of hemodynamic indices showed a marked superiority of continuous retrograde compared with antegrade intermittent blood cardioplegia regarding left ventricular stroke work index (p < 10(-4)) and compared with both methods of intermittent CBCP regarding right ventricular stroke work index (p < 10(-5)). CONCLUSIONS: The use of continuous CBCP resulted in a significant reduction in major cardiac events, better left ventricular performance, and a marked improvement of right ventricular function in comparison with similar solutions of blood cardioplegia administered intermittently, independent of their way of delivery.

Aged↗
PubMed1997

Influence of epoxyeicosatrienoic acids on uterine function.

In spite of the large quantities of epoxyeicosatrienoic acids (EEts) released by reproductive tissues, their function has not yet been determined. In order to analyze the influence of epoxygenase products on isolated uterine function, Clotrimazole, a cytochrome P450 inhibitor was used. The drug decreased isolated rat uterine isometric developed tension (IDT) and frequency (FC). 14,15 EEt induced a contractile response when added at 10(11) M, 8,9 EEt and 11,12 EEt produced an increment of IDT when added to 10(-7) M and 5,6 EEt did not modify IDT values. A contractile stimulatory effect was observed when 14,15 EEt (10(-7) M) was added to a tissue bath preparation containing Clotrimazole (20 microM). On the other hand, uterine contractile response to 14,15 EEt addition was partially abolished by indomethacin (10(-6) M), a well known cyclooxygenase inhibitor. Uterine response to 5,6; 8,9 and 11,12 EEts was not modified by indomethacin. This is the first evidence of 14-15 EEt uterotonic properties, possibly exerted in part through the cyclooxygenase pathway.

8,11,14-Eicosatrienoic Acid↗
PubMed1997

The 80-kD fibronectin fragment increases the production of fibronectin and tumour necrosis factor-alpha (TNF-alpha) in cultured mesangial cells.

The presence of fibronectin (FN) fragments has been demonstrated in several inflammatory processes, and they have been implicated in the recruitment of mononuclear cells. However, the interaction of these FN fragments with resident cells has hardly been studied. We have hypothesized that the 80-kD FN fragment, which includes the RGD cell binding domain of FN, could contribute to the pathogenesis of glomerular damage through the interaction with mesangial cells (MC) via alpha5beta1 integrin. Since an increase in the glomerular deposit of matrix components, particularly FN, is frequently observed in progressive glomerulonephritis, we studied whether its synthesis is modulated by the 80-kD FN fragment and the native FN molecule. While the 80-kD FN fragment stimulated FN in a dose-dependent manner, both at the mRNA and protein level, the whole FN molecule exerted a dual effect. High doses produced FN inhibition, while low doses elicited a certain increase. This stimulation was abrogated by the presence of Sam-1, a MoAb against the alpha-subunit of the alpha5beta1 integrin. Since cytokines play a fundamental role in glomerular injury, we studied the production of TNF-alpha, one of the most powerful mediators of inflammation. TNF-alpha synthesis was induced by the 80-kD FN fragment, in a dose-dependent manner, but not by native FN. When MC were incubated with the 29- and 31-kD FN fragments, which lack the RGD cell binding domain, TNF-alpha secretion was not detected. These results strongly suggest that in cultured MC, the 80-kD FN fragment induces the synthesis of matrix proteins such as FN, and cytokines such as TNF-alpha, via alpha5beta1 integrin. This mechanism could contribute to the perpetuation of renal injury.

Animals↗
PubMed1997

Treatment of nevus spilus with the Q-switched ruby laser.

BACKGROUND: Q-switched lasers have shown to be effective in the removal of unwanted cutaneous pigmentation. Benign cutaneous pigmented lesions represent a heterogeneous group. Nevus spilus is a relatively uncommon pigmented lesion characterized by dark, hyperpigmented dots scattered over a tan-colored macule. OBJECTIVE: A cohort of patients with nevus spilus was studied to determine the effects of Q-switched ruby and Q-switched Nd:YAG laser treatment on clearance of pigment and to evaluate potential side effects. METHODS: Six patients with nevus spilus were treated with the Q-switched ruby laser (QSR). In addition, three lesions received a test treatment with the Q-switched Nd:YAG (QSYAG) laser at 532 or 1064 nm. The results of treatment were documented during follow up visits. RESULTS: Most lesions showed a near-complete or complete response to laser treatment. In one case partial hyperpigmentation occurred after treatment and in one case no follow-up could be obtained. In the three cases that received both QSR and QSYAG laser treatment, the QSR laser was shown to be the most effective in removing pigment. CONCLUSION: Nevus spilus can be treated effectively with the Q-switched ruby laser.

Adolescent↗
PubMed1997

The substitution of digital images for dermatologic physical examination.

OBJECTIVE: To investigate the diagnostic accuracy of clinicians viewing a patient's history and static digital image set compared with clinicians who conducted office-based physical examinations of the same patients. DESIGN: Observational study. SETTING AND PATIENTS: One hundred sixteen adult patients presenting with dermatologic symptoms in a university-based practice who consented to have their skin conditions documented with a still digital camera according to a standardized protocol. MAIN OUTCOME MEASURES: Concordance between office-based dermatologists' diagnoses and 2 remote clinicians' diagnoses using still digital images (resolution, 92 dots per inch) and identical medical history data to render diagnoses. RESULTS: When photographic quality was high and office-based clinician certainty was high, remote clinicians were in agreement more than 75% of the time. Office-based and remote clinicians were in agreement 61% to 64% of the time for all cases. No specific disease category appeared to be more or less amenable to diagnosis based on still digital imagery. The diagnostic certainty of the office-based clinician (reported from 0-10) had the most impact on agreement. When cases with office-based clinician certainty of no more than 7 were compared with cases with certainty of at least 9, agreement increased 54% for remote clinician 1 and 111% for remote clinician 2. As an isolated variable, photographic quality had a modest impact on agreement. CONCLUSIONS: Still digital images can substitute for the dermatologic physical examination in up to 83% of cases. This study provides validation of the store-and-forward concept of telemedicine as applied to dermatology. These results serve as the foundation for field testing of the concept in primary care settings.

Adolescent↗
PubMed1997

Malignant paraganglioma of the prostate: case report, depiction by meta-iodobenzylguanidine scintigraphy and review of the literature.

OBJECTIVE: To describe the 123-I-MIBG scintigraphic, CT, MRI, operative and pathological findings in a case of malignant prostatic paraganglioma and to review the literature on this very rare tumor. EXPERIMENTAL DESIGN: Clinical imaging and pathological correlation of data in a referred patient. SETTING: Regional referral center and tertiary referral academic medical center. PATIENT: 17 year old man presenting with painless hematuria and a large prostatic mass. Interventions and measures. Renal ultrasound, transrectal ultrasound, ultrasound guided prostatic biopsy, pelvic CT and MRI, planar and SPECT 123-I-MIBG scintigraphy, and surgical exploration. RESULTS: The patient had a significant hydronephrosis of the left kidney and marked enlargement (120 ml) of the prostate gland by ultrasound. Ultrasound guided biopsies of the prostate and a left pelvic lymph node revealed a neuroendocrine tumor staining positive for chromogranin. CT and MRI revealed a large tumor of the prostate invading the seminal vesicles, bladder and rectum with extensive pelvic lymph node spread. The primary tumor and one of the nodes were shown to be 123-I-MIBG avid confirming the neuroendocrine nature of the tumor. The lesion was unresponsive to chemotherapy and unresectable at surgical exploration. CONCLUSIONS: To date there have only been 5 reports of prostatic paragangliomas. To our knowledge this is the first to have been studied by MIBG scintigraphy and like most paragangliomas it was MIBG-avid.

3-Iodobenzylguanidine↗
PubMed1997

Chronic hepatitis C with normal aminotransferase levels: a clinical histologic study.

OBJECTIVE: To define chronic hepatitis C virus (HCV) infection among patients with persistently normal aminotransferase levels (PNAL). DESIGN: Retrospective chart review of all patients encountered during 1-yr with positive hepatitis C antibody (anti-C100-3 ELISA), no alternative cause for their liver disease and PNAL for 6 or more consecutive months prebiopsy. Blinded review of liver histology. SETTING: Outpatient hepatology clinics of two academic centers. PATIENTS: Fifty patients with PNAL among 303 with hepatitis C. MEASUREMENTS: Epidemiologic profiles, reasons for seroscreening and confirmatory analyses were tabulated. Histology was reviewed and grading of inflammatory activity and stage of fibrosis was determined by protocol. RESULTS: Among 50 patients with PNAL, 35 (70%) were female, 34 (68%) had parenterally acquired HCV, 44 (88%) abstained (> 2 yr) from ethanol, all were HIV-negative and none pharmacologically immunosuppressed. HCV infection was uniformly confirmed by RIBA II or HCV-RNA assay. The mean level of HCV-RNA by quantitative PCR was 3.79 x 10(5) copies/ml (range, 500 to 1.8 x 10(6) copies/ ml) and by B-DNA, 53 x 10(5) copies/ml (range, 3.5-230 x 10(5) copies/ml). Traditional histoevaluation yielded chronic hepatitis ("active", n = 15; "persistent", n = 25), cirrhosis (n = 7), and normal histology (n = 3). Blinded protocol review of histology (inflammatory grade/fibrotic stage) revealed 0/0 (n = 4), 1/0 (n = 6), 2/0 (n = 17), 2/1 (n = 3), 2/4 (n = 1), 3/0 (n = 2), 3/1 (n = 6), 3/2 (n = 2), and 3/3 (n = 9). CONCLUSIONS: In chronic HCV infection, active inflammation, fibrosis, and variable circulating HCV-RNA levels may coexist with PNAL, particularly among female nondrinkers. Asymptomatic carriers with normal histology comprise 6 to 8% of chronic hepatitis C with PNAL. Management guidelines for this group of patients need to be developed.

Adult↗
PubMed1996

Intervertebral discitis in children: a review of 12 cases.

Twelve children with lumbar discitis were reviewed. The average age at diagnosis was 2.5 years. Seven were girls, and the follow-up varied between 2 and 10 years (average 5 years). The clinical signs were general irritability, abdominal or hip pain and refusal to walk or to sit. The erythrosedimentation rate was elevated in all but two. Radiographic narrowing of the disc space was seen in seven patients. Needle disc aspiration was done in five cases with two being positive for Staphylococcus aureus. Blood culture was positive in one case. Magnetic resonance imaging helped to diagnose the condition in three. Treatment consisted of bed rest and immobilisation of the spine; intravenous antibiotics were given to nine children. The natural course of the disease was benign in all our twelve cases.

Anti-Bacterial Agents↗
PubMed1996

A modulation of glutamate-induced phosphoinositide breakdown by intracellular pH changes.

The influence of intracellular pH (pHi) changes on the formation of inositol phosphate metabolites (IPs) produced by glutamatergic stimulation was studied in 8-day-old rat brain synaptoneurosomes. For this purpose pHi was measured using 2',7'-bis-(2-carboxyl)-5,6-carboxyfluorescein (BCECF) fluorimetric assay in parallel with the basal and receptor-mediated formations of inositol monophosphate (IP1) and inositol bisphosphate (IP2). We found that glutamate (1 mM), which induces a transient acidification (delta pH = -0.05), produces an identical accumulation of IP1 and IP2. K+ (30 mM), which provokes an alkalinization of the internal medium (delta pH = +0.22), mainly leads to the formation of IP1 metabolites. Paired combinations of glutamate with 1, 5 and 10 mM NH4+ finally result in an alkalinization of the intrasynaptoneurosomal medium. These combinations produce a strong decrease of the IP2 level concomitant with an increase of the IP1 formation, compared to the levels of IP1 and IP2 evoked by glutamate alone. The total amount of IPs (IP1 + IP2) produced by these combinations is not different from that obtained with glutamate alone. Paired combinations of carbachol with NH4+ produce an identical alkalinization to that produced by NH4+ alone. These combinations produce an increased IP1 accumulation, while the IP2 formation is slightly decreased. When the internal medium is acidified by diminishing the external concentration of Na+, the ratio IP1/IP2 produced after metabotropic glutamate receptor (mGluR) activation is shifted to lower values, while it is not affected for the muscarinic stimulation. These data suggest that the mGluR-associated pathway in synaptoneurosomes is sensitive to pHi shifts, while the muscarinic receptor-associated pathway is less altered when pHi is manipulated. It may be proposed that pH-sensitive inositol phosphate dephosphorylating systems, i.e. phosphatases, are associated with mGluRs in this preparation.

Animals↗
PubMed1996

Testicular microlithiasis as a predictor of intratubular germ cell neoplasia.

Sonographically detected testicular microlithiasis is an uncommon condition, which in recent years has been demonstrated with increased prevalence in patients with testicular tumors. We report a case of a 31-year-old man with left testicular carcinoma and right intratubular germ cell neoplasia diagnosed by biopsy of the right testis at the time of left radical orchiectomy. In this case, preoperative ultrasound revealed right testicular microlithiasis, signaling the presence of intratubular germ cell neoplasia. We propose ultrasound as a noninvasive tool for selecting patients for testicular biopsy.

Adult↗
PubMed1996

Laser treatment of tattoos in darkly pigmented patients: efficacy and side effects.

BACKGROUND: Many modalities for the treatment of tattoos and pigmented lesions produce a greater risk of complications in Fitzpatrick types V and VI skin because of an increased incidence of adverse pigmentary changes and keloidal scarring. In fair-skinned persons Q-switched lasers have proved effective in removing pigmented lesions and tattoos without scarring. OBJECTIVE: This study was conducted to determine the efficacy and effects of Q-switched lasers on a small series of darkly pigmented patients with tattoos. METHODS: Four patients of Ethiopian origin with facial and neck tribal tattoos were treated with both the Q-switched ruby and Nd:YAG lasers. One black woman with a multicolored tattoo on the mid chest was treated with the Q-switched ruby laser. RESULTS: Clearing of all lesions was seen. The treatments did not result in scarring or permanent pigment changes other than the ones intended. CONCLUSION: Our results indicate that in darkly pigmented patients, Q-switched laser treatment of tattoos can be performed successfully. The longer wavelength Q-switched Nd:YAG laser is recommended when removing tattoos in darker complected persons. A test treatment is advised before treatment of large skin areas.

Adult↗
PubMed1996

Ontogenetic development of proline intestinal transport in the domestic fowl.

1. The proline disappearance from the jejunal and ileal lumen of chickens aged from 1 day to 15 weeks were studied using a perfusion method "in vivo". 2. A decrease in proline transport was observed from younger to older animals. The 2 intestinal segments showed different behaviours, the 1-day and 1-week-old animals showed the same value in the jejunum, whereas in the ileum a progressive decrease in proline transport was observed from the first week of life. 3. The differences observed in the 2 segments could be attributed to the different rates of growth of the jejunum and ileum with age; the jejunum showed a peak of growth in the second week of life whereas the ileum showed a peak of growth in the first week. Proline transport in the jejunum decreased until the fifth week and remained constant thereafter.

Aging↗
PubMed1996

Comparative study of propofol versus midazolam in the sedation of critically ill patients: results of a prospective, randomized, multicenter trial.

OBJECTIVES: To compare the effectiveness, characteristics, duration of action, hemodynamic and biochemical effects, and side effects of propofol and midazolam used for continuous intravenous sedation of ventilated critically ill patients. DESIGN: Multicenter, prospective, randomized, nonblinded study. SETTING: Nine Spanish general intensive care units (ICUs). PATIENTS: Ninety-eight patients admitted to the ICU who were mechanically ventilated and required sedation for a minimum of 48 hrs. INTERVENTIONS: Propofol or midazolam was used for induction and maintenance of continuous intravenous sedation for a maximum of 5 days. The effectiveness of those two regimens was assessed according to their effects on ventilatory management and the presence of agitation. MEASUREMENTS AND MAIN RESULTS: In 93% of the patients studied, there was a medical cause necessitating mechanical ventilation. The mean (+/-SD) duration of sedation was 81 +/- 25 hrs and 88 +/- 27 hrs for the propofol and midazolam groups, respectively. The induction dose was 2.24 +/- 0.43 mg/kg over 318 +/- 363 secs for propofol, and 0.22 +/-0.07 mg/kg over 33 +/-29 secs for midazolam. The maintenance dose was 2.8 +/-1.1 mg/kg/hr for propofol and 0.14 +/- 0.10 mg/kg/hr for midazolam. There was no difference regarding the opiate and muscle relaxant requirements between the two groups. Sedation with propofol was more effective in achieving patient-ventilator synchrony than that with midazolam after the first hour of treatment (p < .01). Patients sedated with propofol awoke more rapidly and with less variability that those patients sedated with midazolam (23 +/- 16 mins vs. 137 +/- 185 mins, respectively, p < .05), particularly in those patients requiring deep sedation (27 +/- 16 mins vs. 237 +/- 222 mins, respectively, p < .01). No hemodynamic or biochemical changes were detected in any of the treatment groups. During induction, five patients in the propofol group and two patients in the midazolam group had hypotension. CONCLUSIONS: In this population of critically ill patients, propofol is an effective and safe alternative for sedation, with some advantages, such as short duration of action and high effectiveness over the conventional regimen with benzodiazepines and opiates.

Adolescent↗