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Biomedical subjects

A Rodriguez

Publications and source records attributed to A Rodriguez.

At least 433 records · Page 24Linked to original sources
PubMedDate not supplied

Radiological evaluation of the craniocervical junction in bone dysplasias and other related syndromes.

The craniocervical junction, a vital but anatomically complex region, presents additional interpretative challenges in patients with skeletal dysplasias and other syndromes involving the musculoskeletal apparatus. Our objective was to review the radiological evaluation used in such conditions; to do so, we identified retrospectively all of the occipitocervical studies done during the last 3 years at our institution on patients with skeletal dysplasias and related syndromes. The 28 cases thus found were reviewed and the different diagnostic modalities identified; the diagnostic findings were summarized and classified into osseous and soft tissue abnormalities. The standard criteria for cervical instability and cord compression were compared with measurements reported in our selected cases. The lateral radiograph of the cervical spine was the first diagnostic test, followed by additional flexion-extension views and sagittal spin-echo magnetic resonance imaging; no conclusive diagnostic criteria for occipitoatlantal instability in children with bone dysplasias were identified.

Adolescent↗
PubMedDate not supplied

13C-urea breath test for the diagnosis of Helicobacter pylori infection before treatment: is citric acid necessary?

AIM: 13C-urea breath test is one of the best methods for the diagnosis of Helicobacter pylori infection. Although a citric acid solution is generally used prior to urea intake, the superiority of this strategy has not been sufficiently demonstrated. Thus, our aim was to compare 13C-urea breath test with and without citric acid solution, to evaluate whether 13C-urea breath test can also achieve favourable results when the test meal is omitted. METHODS: 13C-urea breath test with and without citric acid were compared prospectively in 53 subjects without prior Helicobacter pylori eradication therapy prescription. Basal samples and at 15', 30', and 45' after taking 100 mg of 13C-urea were obtained. The gold standard for Helicobacter pylori diagnosis was the 13C-urea breath test result with citric acid at 30', and "Delta Over Baseline" values >5 at that time were considered positive. RESULTS: The prevalence of Helicobacter pylori infection was 68%. Mean Delta Over Baseline values with citric acid at 15', 30' and 45' were: 29.6+/-39, 30.8+/-37 and 24.6+/-27; whereas respective values without citric acid were lower: 14.9+/-22, 12.2+/-17 and 10D+/-13 (p<O. 001 for all comparisons, Wilcoxon test for paired data). Thus, the area under the curve (constructed with Delta Over Baseline values at different times) with citric acid was 85+/- 102, and 37+/-50 without citric acid [p<0.001). Correlation coefficient between Delta Over Baseline values with and without citric acid at 30' was 0.73 (p<0.0001). The percentage of subjects achieving the highest Delta Over Baseline value at 15', 30' and 45' with citric acid was 51%, 30% and 19%, whereas without citric acid it was 51%, 26% and 23% (non-significant differences). The area under receiver operating characteristic curve for 13C-urea breath test without citric acid was: 0.98 at 15', 1 at 30' and 0.97 at 45'. The best cut-off point for 13C-urea breath test without citric acid at 30' was anywhere between 3. 3 and 3.9 (that is, a lower value than that usually considered with citric acid), with 100% (95% confidence interval, 90-100%) sensitivity and 100% [82-100%) specificity CONCLUSIONS: 13C-urea breath test values with citric acid are higher than those obtained without citric acid, although this difference does not imply a diagnostic superiority in untreated patients when considering 13C-urea breath test without citric acid at 30'. Therefore, for the diagnosis of Helicobacter pylori infection in untreated patients, citric acid solution in 13C-urea breath test protocol can be omitted.

Adult↗
PubMedDate not supplied

The conjunctivitis of solar (actinic) prurigo.

Solar (actinic) prurigo (SP) is an abnormal reaction to sunlight that affects mostly the Indian and mestizo populations of America, and is well known in Canada and the United States. It is quite common in Mexico, Central, and South America, although rare in Europe. It usually starts in childhood in both sexes and in about 30-50% of cases involves the oral and ocular mucosa. In this study we present the clinical and histopathologic conjunctival findings in 11 of 105 children with SP. Clinically the most important features were photophobia, some degree of pterygium, and pinguecula, hyperemia, Trantas' dots, hyaline exudate, and follicles. Histopathologically the changes were epithelial, such as epidermoid metaplasia and absence of goblet cells, and stromal changes, which were the most diagnostically relevant. These consisted of lymphocytic inflammatory infiltrates, usually with eosinophils, melanosis, and solar elastosis. We believe this constellation of criteria will be useful for a better characterization of SP.

Adolescent↗
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Fetal androgen exposure inhibits fetal rat lung fibroblast lipid uptake and release.

Fetal lung fibroblasts provide lipid substrate for type II cell surfactant phospholipid synthesis. This process is developmental and glucocorticoid dependent. Previous studies in our laboratory demonstrating sex differences in several aspects of lung maturation suggest that these differences may be due to effects of fetal androgens. Based on these studies, we hypothesized that fetal lung fibroblast triglyceride metabolism is determined by opposing effects of fetal androgens and glucocorticoids. To model the effects of androgens on fetal lung fibroblast triglyceride metabolism, pregnant rats were treated with dihydrotestosterone (DHT) 1 mg/kg/day from the days 15 to 20 of gestation, and changes in triglyceride content of freshly isolated fetal rat lung fibroblasts (FRLF) and rates of uptake and prostaglandin E2 (PGE2)-mediated release by cultured FRLF in response to glucocorticoids in the presence or absence of DHT in vitro were measured. During lung development, the triglyceride content and rate of uptake of female-derived FRLF increased 3.5- and 4.8-fold, respectively, between days 18 and 20 of gestation. From days 19 to 22, male FRLF trigyclyceride content and rate of uptake were lower than the content and uptake by female FRLF. Maternal DHT treatment inhibited the normal developmental increase in fibroblast triglyceride content and rate of uptake between days 19 and 22 by both male and female FRLF. In the absence of maternal DHT, in vitro dexamethasone stimulated triglyceride uptake 3-fold by day 21 in FRLF. This effect was blocked by maternal pretreatment with DHT. Maternal DHT exposure prevented stimulation of triglyceride release by PGE2. Although in vitro dexamethasone stimulated triglyceride release by maternal DHT-exposed fibroblasts, it did not enhance the response to PGE2. These data suggest that in utero exposure to androgens (1) delay the developmental increase in triglyceride content and (2) oppose the effects of glucocorticoid on cultured FRLF triglyceride uptake and PGE2-mediated release.

Animals↗
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MR imaging of traumatic diaphragmatic rupture.

The diagnosis of traumatic rupture of the diaphragm may remain elusive despite a variety of imaging options including CT and sonography. Direct sagittal and coronal magnetic resonance images provided a definitive diagnosis of left diaphragmatic rupture with herniation of colon into the thorax.

Adult↗
PubMedDate not supplied

Fracture of the radial head with associated elbow dislocation: results of treatment using a floating radial head prosthesis.

OBJECTIVES: To assess elbow function, complications, and problems of radial head fractures associated with elbow dislocation receiving surgical treatment with a floating prosthesis. DESIGN: Prospective clinical study. SETTING: University Hospital, Orthopaedic Department, Sart Tilman, Liège, Belgium. PATIENTS: Eleven consecutive adult patients were treated with a floating prosthesis for acute radial head fractures associated with elbow dislocation from January 1994 to September 1996. INTERVENTION: The floating radial head prosthesis (Tornier SA, Saint-Ismier, France) was used in all our patients. The implant is in two parts: a radial head made of high-density polyethylene enclosed in a cobalt-chrome cup, which articulates in a semiconstrained manner with the spherical end of a cemented intramedullary stem. The implants were inserted within the first week following the injury (range 2 to 7 days). Three cases also required internal fixation of the coronoid process of the ulna; in one case plate fixation of an olecranon fracture was also performed. MAIN OUTCOME MEASUREMENTS: Patients were assessed by physical examination, a functional rating index (Morrey et al.), and radiographs. The parameters evaluated were motion, stability, pain, and grip strength. Potential complications such as infection, prosthetic failure, or dislocation were investigated. RESULTS: The minimum follow-up time was two years (mean 32 months, range 24 to 56 months). Four patients were considered to have excellent results, four patients were considered to have good results, two patients had fair results, and one patient had a poor result. There were no cases of infection, prosthetic failure, or dislocation. No patient required prosthetic revision. CONCLUSION: The basic principle of maintaining anatomic and physiologic relationships applies when deciding on treatment for radial head fractures with associated elbow dislocation. The loss of lateral osseous support will render the elbow grossly unstable. We believe that a floating prosthesis may be indicated in Mason Type III radial head fractures associated with elbow dislocation, especially in the presence of associated destabilizing fractures. Well-controlled comparative randomized studies will be needed to delineate the optimal treatment for a given situation.

Adult↗
PubMedDate not supplied

Histophysiological and morphometric studies of the post-natal development of rat vas deferens.

The post-natal growth and differentiation of the vas deferens was studied in rats aged 1-180 d by light, and with transmission electron microscopy in parallel with a radioimmunoassay of serum testosterone. During the first week and the major part of the second week of the post-natal life the vas deferens presented embryological features. Differentiation of the proximal and distal segments of the vas started 12 d after birth. At 25 d, the epithelium of the mucosa in the distal segment already showed some adult histologic characteristics. The weight notably increased between 1 and 45 d and the higher rates of growth of their histologic components occurred until 45 or 60 d, in parallel to testosterone serum levels. These results suggest that growth and differentiation of the vas deferens are androgen-dependent events and precede the end of the first spermatogenic cycle, assuring the viability of spermatozoa that will enter the duct.

Aging↗
PubMedDate not supplied

Review of ocular ultrasonography.

In this paper, the basics, screening technique and major indications of ocular ultrasound are described. This diagnostic technique proved to be an essential tool to examine intraocular structures when opacified ocular media inhibit direct examination and to evaluate retrobulbar structures when exophthalmos is evident.

Animals↗
PubMedDate not supplied

Prenatal diagnosis of X-linked ichthyosis using molecular cytogenetics.

A case is presented in which X-linked ichthyosis was diagnosed prenatally using fluorescence in situ hybridization. Fetal sex was known by second trimester ultrasound in a woman with very low second trimester MSUE3. All of the 15 maternal peripheral blood metaphase spreads examined displayed two hybridization signals on one X chromosome (one in the steroid sulfatase region (Xp22.3) and one in the centromeric region), but only one hybridization signal (in the X centromeric region) on the other X chromosome. Thus, one of the X chromosome had a deletion in the Xp22.3 region, a result which was consistent with carrier status for steroid sulfatase deficiency and X-linked ichthyosis. In the 15 metaphase spreads that were examined from the amniotic fluid sample, the X chromosome displayed one hybridization signal in the control region, but no hybridization signal in the steroid sulfatase region. Thus, the X chromosome of this male fetus had a deletion in the steroid sulfatase region, a result that was consistent and demonstrated postpartum X-linked ichthyosis.

Adult↗
PubMedDate not supplied

Influence of high density lipoprotein on esterified cholesterol stores in macrophages and hepatoma cells.

The ability of high density lipoproteins (HDL) to induce the clearance of cholesteryl esters from cultured cells has been explored. Studies using the J774 mouse macrophage cell line showed that these cells are not stimulated to clear esterified cholesterol upon exposure to HDL. This was observed over a wide range of HDL concentrations (10 to 1000 micrograms/ml HDL protein), and the lack of stimulation was not influenced by a number of factors relating to the preparation of the HDL, such as HDL subfraction, varying extents of lecithin:cholesterol acyltransferase modification, or heparin-Sepharose chromatography to remove particles containing apo E. Neither the method of loading the cells with esterified cholesterol nor the physical state of the lipid droplets affected the inability of HDL to elicit esterified cholesterol clearance. In the presence of the acyl CoA:cholesterol acyltransferase inhibitor, Sandoz 58-035, where a high level of intracellular free cholesterol was generated, efflux of only a small fraction of the excess free cholesterol to HDL was observed. J774 cells were able to clear esterified cholesterol efficiently in the presence of cholesterol-free apolipoprotein HDL/phospholipid particles, indicating that the cells have the capacity to clear esterified cholesterol. Fu5AH hepatoma cells and P388.D1 mouse macrophage cells also failed to clear esterified cholesterol in response to HDL. In contrast, mouse peritoneal macrophages cleared esterified cholesterol efficiently to HDL, indicating that there are fundamental differences between mouse peritoneal macrophages and the other cells types studied in regard to cholesterol metabolism as influenced by HDL.

Animals↗
PubMedDate not supplied

Intracranial venous thrombosis in young women.

Twenty women of child-bearing age with intracranial venous thrombosis are reported. Thirteen developed thrombosis post-partum; 6 while on oral contraceptives. In one patient no cause was found. All diagnoses were confirmed by carotid angiography and in 10 out of 14 patients laboratory data indicated a hypercoagulable state. Coagulation studies were performed in 14 normal puerperal women, matched by age, who served as controls. No statistical differences was found between thrombotic and control groups. Radiologic signs of sino-venous occlusion are reviewed. Conservative treatment with anti-edematous agents, anticonvulsants and antiplatelet aggregants is advocated.

Adolescent↗
PubMedDate not supplied

Outcomes of vitreoretinal surgery for retinal detachment after LASIK for myopia.

PURPOSE: To report and compare outcomes of vitreoretinal surgery for repair of retinal detachment in myopic patients with and without previous laser-assisted in situ keratomileusis (LASIK). METHODS: This is a descriptive retrospective observational study with a control group for comparison that consisted of the analysis of clinical and surgical charts of patients who underwent vitreoretinal procedures for retinal detachment at the Fundación Oftalmologica Nacional between January 1995 and December 2002. The authors identified those myopic patients who had previous history of LASIK and an age- and myopia-matched control group without refractive surgery. RESULTS: The sample contains 24 myopic eyes of 22 patients with previous LASIK and 23 myopic eyes without previous LASIK in the control group, matched by age and myopia. Mean refractive error was -9.4 D before LASIK for the cases group and -11.2 for the control group. Poor preoperative best-corrected visual acuity was present in 71% of cases and 61% of controls (p=0.489). Macula off retinal detachment was found in 17 eyes in both groups. Five eyes required at least two procedures, achieving 91% (20 eyes) reattachments at the end of follow-up in each group. Final best-corrected visual acuity was better than 20/100 in 15 eyes (62.5%) in the LASIK group and 17 eyes (74 %) in the control group (p=0.659). CONCLUSIONS: Retinal detachment in patients with previous myopic LASIK has similar characteristics as in myopic patients without refractive surgery. Current vitreoretinal surgery is of good prognosis as the retina was successfully reattached in most cases in both groups.

Adolescent↗
PubMedDate not supplied

T cell receptor V-segment frequencies in peripheral CD8+ T cells in aging.

Infections are a major cause of illness and death amongst elderly people. Peripheral blood CD8+ T lymphocytes --which play a crucial role in host defence against viral infections--, are divided in subsets based upon the expression of several cell and activation markers. In senescence changes and variations in peripheral CD8+ T lymphocyte compartment have been described, and such a decrease in the CD8+CD45RA+ lymphocytes. In this report the T V alpha and Vbeta cell specificities repertoire usage in aging subjects were studied by the use of seven different monoclonal antibodies specific for defined regions of the TCR. Except for the Vbeta6subfamily, no differences between old and control subjects in frequency of T cells bearing selected V alphabeta epitopes, were observed.

Adolescent↗
PubMedDate not supplied

The accuracy of diagnostic laparoscopy in trauma patients: a prospective, controlled study.

BACKGROUND: Numerous studies advocate the use of diagnostic laparoscopy (DL) for abdominal trauma, but none have documented its ability to diagnose specific injuries. This study tests the hypothesis that DL can accurately identify all significant intra-abdominal injuries in trauma patients. METHODS: Of trauma patients requiring laparotomy for presumed injuries, 47 underwent DL followed by laparotomy. Injuries noted at laparoscopy were compared with those found at laparotomy. RESULTS: Of these, 14 patients had no significant injuries necessitating operative intervention noted at laparoscopy and celiotomy. The remaining 33 patients harbored 93 significant injuries at laparotomy, of which only 57.0% were found by DL. DL possessed poor sensitivity (<50%) for injuries to hollow viscera. Despite DL's poor performance in finding specific injuries, it possessed excellent sensitivity (96.2%), and specificity (100%) for determining the need for therapeutic celiotomy. CONCLUSIONS: DL offers no clear advantage over diagnostic peritoneal lavage and computed tomography in blunt trauma. Its utility lies in assessment of the need for laparotomy in patients with penetrating wounds. Currently, DL cannot consistently identify all abdominal injuries, disqualifying it as a therapeutic tool in abdominal trauma.

Abdominal Injuries↗
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The next generation of managed mental health care.

The rise in mental health claims and the tremendous expansion of psychiatric facilities and services have put payers and providers alike on the defensive. Payers cut benefits, while providers rush to justify even clearly needed care. The venturesome in both camps will be intrigued by General Telephone of California's comprehensive, managed mental health care program, combining the PPO concept with provider risk and strong case management, as described by the authors, Vice Presidents of Preferred Health Care, Ltd.

California↗
PubMedDate not supplied

Analysis of deaths due to injury in Milano: preliminary results.

We reviewed all trauma deaths occurring in the urban area of Milan during one year. Autopsy reports were cross-referenced with pre- and in-hospital records and the Injury Severity Score was calculated by a senior surgeon. Causes of deaths were defined as central nervous system injury (CNS), hemorrhage (HEM), combined central nervous system injury and hemorrhage (CNS + HEM), and burns (BURN). Places of death were considered the scene (DOS), during transportation (DOA), the emergency room (DER), and hospital. Two multidisciplinary commissions reviewed patient reports and deaths were judged non-preventable, possibly preventable or frankly preventable, using the unanimous decision rule. The TRISS method was used to calculate the probability of survival for in-hospital deaths. Overall trauma deaths were 255 with 78.04% blunt and 16.08% penetrating traumas. Burns accounted for 5.88%. CNS and CNS + HEM caused 171 (67.05%) deaths. DOS were 91, DOA 48, DER 34, and in-hospital deaths 33. Victims found dead (49 individuals) were excluded from further analysis. The commissions classified 56.31% of deaths as non-preventable, 32.03% as possibly preventable and 11.65% as frankly preventable. The Injury Severity Score decreased from DOS to in-hospital deaths (p < 0.05). The preventability rate was higher for in-hospital deaths (p < 0.05). The results of this study suggest that the development of a tiered trauma system in Milan is mandatory.

Adult↗