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Biomedical subjects

C Carvalho

Publications and source records attributed to C Carvalho.

At least 19 recordsLinked to original sources
PubMed2001

Chemoreduction for retinoblastoma may prevent intracranial neuroblastic malignancy (trilateral retinoblastoma).

OBJECTIVE: To evaluate whether neoadjuvant intravenous chemotherapy (chemoreduction) for retinoblastoma reduces the risk for associated intracranial neuroblastic tumor (trilateral retinoblastoma). DESIGN: Retrospective consecutive case series. PARTICIPANTS: Two hundred fourteen consecutive children with newly diagnosed retinoblastoma treated at a major ocular oncology center from January 1, 1995, to July 1, 1999. MAIN OUTCOME MEASURE: Development of associated intracranial neuroblastic tumor (trilateral retinoblastoma). RESULTS: During the 54-month study period, 142 patients (66%) received chemoreduction (consisting of vincristine sulfate, etoposide phosphate, and carboplatin therapy) as part of their treatment strategy (chemoreduction group), whereas 72 (34%) were treated with nonchemoreduction methods (nonchemoreduction group). In the chemoreduction group, no associated intracranial neuroblastic tumor developed during the mean 47-month follow-up. Based on a recent meta-analysis of the prevalence of trilateral retinoblastoma, we would have expected the intracranial tumor to develop in 5 to 15 patients with hereditary retinoblastoma. This lack of associated trilateral retinoblastoma in the chemoreduction group was significantly less than expected using binomial distribution (P<.001). In the nonchemoreduction group, associated intracranial tumor (pinealoblastoma) developed in 1 patient, a finding consistent with the expected frequency. CONCLUSION: Chemoreduction protects against the highly fatal associated intracranial neuroblastic tumor (trilateral retinoblastoma). This observation is especially important in children with bilateral or familial retinoblastoma who are at greatest risk for this brain tumor.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Conjunctival lymphoid tumors: clinical analysis of 117 cases and relationship to systemic lymphoma.

OBJECTIVE: To investigate the clinical features of conjunctival lymphoid tumors and factors predictive of systemic lymphoma. DESIGN: Retrospective, observational case series. SETTING: Clinical practice of ocular oncology. PARTICIPANTS: The participants included 117 consecutive patients with lymphoid tumors of the conjunctiva treated at the Oncology Service of Wills Eye Hospital between 1974 and 1999. MAIN OUTCOME MEASURE: The main outcome measure was the development of systemic lymphoma. Cox proportional regression models were used to calculate the risk of eventual systemic lymphoma. Kaplan-Meier survival estimates were used to analyze the development of systemic lymphoma as a function of time. RESULTS: There were 55 males (47%) and 62 females (53%); 110 patients (94%) were white and 7 patients (6%) were African AMERICAN: The mean age at ocular presentation was 61 years, and the conjunctival lymphoid infiltrate was unilateral in 72 patients (62%) and bilateral in 45 patients (38%). In 8 patients (7%), initial unilateral conjunctival disease evolved into bilateral involvement over a mean of 32 months. Additional sites of ocular involvement were found in 27 patients (23%) and included lymphoid tumor in the eyelid in 3 cases, orbit in 18, choroid in 5, and vitreous in 1. Systemic lymphoma was known to exist before ocular diagnosis in 16 patients; (14%; for a mean of 51 months) and was found subsequent to ocular diagnosis in 20 patients (17; at a mean of 21 months). Therefore, of 117 patients with conjunctival lymphoid infiltration, 36 (31%) had or eventually developed systemic lymphoma, and 81 (69%) did not manifest systemic lymphoma during the mean follow-up of 38 months. Of the 64 patients with unilateral conjunctival involvement, 11 (17%) manifested systemic lymphoma, and of the 53 patients with bilateral involvement, 25 (47%) manifested systemic lymphoma. By univariate analysis, the clinical factors at date first seen predictive of the presence or development of systemic lymphoma included location of the tumor at an extralimbal site (fornix or midbulbar conjunctiva; P = 0.02) and increasing number of conjunctival tumors (P = 0.02). Using Kaplan-Meier life table analysis of those 101 patients who had conjunctival lymphoid tumor(s) and no evident systemic lymphoma at presentation, systemic lymphoma was eventually discovered in 7% of patients at 1 year, 12% at 2 years, 15% at 5 years, and 28% at 10 years. Overall, only one patient (<1%) died of systemic lymphoma, at 28 months after the diagnosis of the ocular disease. CONCLUSIONS: Lymphoid tumors of the conjunctiva are associated with systemic lymphoma in 31% of patients. Systemic lymphoma is found more often in those patients with forniceal or midbulbar conjunctival involvement and in those with multiple conjunctival tumors. Long-term systemic follow-up is advised, because related systemic lymphoma can manifest many years later.

Adult↗
PubMed2001

Left ventricular mass and function in young obese women.

OBJECTIVE: Obesity is associated with a high mortality rate due to cardiovascular disease. Left ventricular (LV) hypertrophy has been described in relation to obesity. The aim of this study was to evaluate echocardiographically the LV mass and function in young obese women as compared to lean women with similar characteristics. DESIGN: Prospective study. SUBJECTS: Eighty-two young women (< or =40 y), with obesity degree varying from I to III (BMI from 30 to 50 kg/m2) were compared to eighty young lean women. All of them were normotensive, none had cardiovascular complaints or any previous history of pulmonary disease, and none were taking any medication. The LV mass was calculated by the Devereux and Reichek formula. RESULTS: The LV mass was strongly increased in all obese groups (P<0.00003 to 0.000005) compared to lean subjects. LV mass adjusted indexes for height, BMI or volume were also increased compared to lean subjects and when adjusted for weight it was decreased. However when comparing LV mass/body surface area index this difference was not statistically significant. The linear regression analysis showed a strong association between the degree of obesity and LV mass, (r=0.52, P<0.001). Systolic and diastolic function in obese patients were similar to lean subjects, except for a lower E/A ratio in the obese group (P=0.005). CONCLUSION: In asymptomatic young obese women, there are some echocardiographic findings suggesting early cardiac involvement that seems to be related to the degree of obesity.

Adult↗
PubMed2001

Cancer metastatic to the orbit: the 2000 Robert M. Curts Lecture.

PURPOSE: To report the demographics and clinical features of a large series of patients with orbital metastasis. METHODS: Retrospective chart review on 100 consecutive patients and a literature review on orbital metastasis. RESULTS: Of 100 patients, the primary tumor site was breast in 53 (53%), prostate gland in 12 (12%), lung in 8 (8%), skin (melanoma) in 6 (6%), kidney in 5 (5%), gastrointestinal tract in 5 (5%), choroid (melanoma) in 2 (2%), parotid gland in 1 (1%), and adrenal gland (neuroblastoma) in 1 (1%). Of patients in whom a detailed history was available, there was no history of cancer at the time of presentation in 19%. In 10%, the primary tumor remained undetected despite systemic evaluation. There were 36 male patients and 64 female patients whose mean age at diagnosis was 62 years (median 60 years, range 5 to 91 years). Both the right and left orbits were affected equally, and 4 cases (4%) were bilateral. The most frequent clinical findings were limited ocular motility (54%), proptosis (50%), and palpable mass (43%). The diagnoses were established by history, systemic survey, imaging studies, and biopsy. Treatment included chemotherapy, hormone therapy, irradiation, surgical excision, or observation, depending on clinical circumstances. Among patients with sufficient follow-up, 95% died of metastasis, with overall mean survival of 15 months (median 15 months; range 3 to 96 months) after orbital diagnosis. CONCLUSIONS: The most common primary cancers that metastasize to the orbit are breast, prostate gland, and lung cancer. In 19%, there is no history of cancer when the patient presents with ophthalmic symptoms and in 10% the primary site remains obscure despite systemic evaluation. The systemic prognosis is generally poor.

Adolescent↗
PubMed2001

Endoscopic vitreoretinal surgery for complicated proliferative diabetic retinopathy.

PURPOSE: To evaluate the indication for endoscopic vitreoretinal surgery in proliferative diabetic retinopathy (PDR). METHODS: Chart review of consecutive cases of vitreoretinal surgery for PDR performed by one of the authors (Y.L.F.) over a 2-year period. RESULTS: Endoscopic vitreoretinal surgery was performed in 8 of 41 (19.5%) eyes. The surgical indications were small pupil (3), hyphema (3), pseudophakia with fibrotic posterior capsule (1), and pars plana neovascularization with anterior tractional retinal detachment (6). CONCLUSION: Endoscopic vitreoretinal surgery, by enhancing the visualization of the retroirideal space, is a useful technique in PDR with opaque ocular media and/or neovascularization of the pars plana and ciliary body.

Adult↗
PubMed2001

Retinal angiomatous proliferation in age-related macular degeneration.

BACKGROUND: It is known that choroidal neovascularization (CNV) in age-related macular degeneration (ARMD) may erode through the retinal pigment epithelium, infiltrate the neurosensory retina, and communicate with the retinal circulation in what has been referred to as a retinal-choroidal anastomosis (RCA). This is extremely common in the end stage of disciform disease. In recent years, the reverse also seems to be possible, as angiomatous proliferation originates from the retina and extends posteriorly into the subretinal space, eventually communicating in some cases with choroidal new vessels. This form of neovascular ARMD, termed retinal angiomatous proliferation (RAP) in this article, can be confused with CNV. PURPOSE: The purpose of this article is 1) to review the clinical and angiographic characteristics of a series of patients with RAP and 2) to propose a theoretical sequence of events that accounts for the neovascularized process. METHODS: In this retrospective clinical and angiographic analysis, 143 eyes with RAP (108 patients) were reviewed and classified based on their vasogenic nature and course. Clinical biomicroscopic examination, fluorescein angiography, and indocyanine green angiography were used to evaluate patients. RESULTS: The results of this series suggest that angiomatous proliferation within the retina is the first manifestation of the vasogenic process in this form of neovascular ARMD. Dilated retinal vessels and pre-, intra-, and subretinal hemorrhages and exudate evolve, surrounding the angiomatous proliferation as the process extends into the deep retina and subretinal space. One or more dilated compensatory retinal vessels perfuse and drain the neovascularization, sometimes forming a retinal-retinal anastomosis. Fluorescein angiography in these patients usually revealed indistinct staining simulating occult CNV. Indocyanine green angiography was useful to make an accurate diagnosis in most cases. It revealed a focal area of intense hyperfluorescence corresponding to the neovascularization ("hot spot") and other characteristic findings. Based on understanding of the nature and progression of the neovascularized process, patients with RAP were classified into three vasogenic stages. Stage I involved proliferation of intraretinal capillaries originating from the deep retinal complex (intraretinal neovascularization [IRN]). Stage II was determined by growth of the retinal vessels into the subretinal space (subretinal neovascularization [SRN]). Stage III occurred when CNV could clearly be determined clinically or angiographically. A vascularized pigment epithelial detachment and RCA were inconsistent features of this stage. CONCLUSIONS: Retinal angiomatous proliferation appears to be a distinct subgroup of neovascular ARMD. It may present in one of three vasogenic stages: IRN, SRN, or CNV. Whereas ICG angiography is helpful in diagnosing RAP and in documenting the stage of the neovascularized process, it is frequently difficult to determine the precise nature and location of the new vessel formation. It is important for clinicians to recognize the vasogenic potential and the associated manifestations of this peculiar form of neovascular ARMD so that a proper diagnosis can be made, and when possible, an appropriate management administered.

Aged↗
PubMed2000

Combination of clinical factors predictive of growth of small choroidal melanocytic tumors.

OBJECTIVE: To better define the effect of individual risk factors and combinations thereof on the growth of small choroidal melanocytic tumors. DESIGN: Retrospective analysis. SETTING: Clinical practice of ocular oncology. PATIENTS: The study included 1287 patients with small suspicious choroidal melanocytic tumors, measuring 3 mm or less in thickness, managed with observation. RESULTS: On multivariate analysis, the clinical risk factors predictive of growth of small choroidal melanocytic tumors include tumor thickness greater than 2.0 mm, posterior tumor margin touching the disc, visual symptoms, orange pigment, and subretinal fluid. Tumor growth was detected in 4% of those patients with no risk factors. Growth was detected in approximately 36% of patients with 1 risk factor, 45% of patients with 2 risk factors, 50% of patients with 3 risk factors, 51% of patients with 4 risk factors, and 56% of patients with all 5 risk factors. The combination of risk factors offering the greatest risk for growth was tumor thickness greater than 2.0 mm, tumor margin touching disc, and subretinal fluid that was associated with tumor growth in 63% of the affected patients. The relative risk for growth was 1.9 for 1 factor, 3.8 for 2 factors, 7.4 for 3 factors, 14.1 for 4 factors, and 27.1 for all 5 risk factors combined. CONCLUSIONS: Five risk factors for growth of small choroidal melanocytic tumors have been identified. The combinations of various factors increase the risk for tumor growth from 4% if no factors are present to more than 50% if 3 or more risk factors are present. These factors may be important when counseling patients with small suspicious choroidal melanocytic tumors.

Choroid Neoplasms↗
PubMed2000

Selective expansion of intraepithelial lymphocytes expressing the HLA-E-specific natural killer receptor CD94 in celiac disease.

BACKGROUND & AIMS: Celiac disease is a gluten-induced enteropathy characterized by the presence of gliadin-specific CD4(+) T cells in the lamina propria and by a prominent intraepithelial T-cell infiltration of unknown mechanism. The aim of this study was to characterize the subset(s) of intraepithelial lymphocytes (IELs) expanding during active celiac disease to provide insights into the mechanisms involved in their expansion. METHODS: Flow-cytometric analysis of isolated IELs and/or immunohistochemical staining of frozen sections were performed in 51 celiac patients and 50 controls with a panel of monoclonal antibodies against T-cell and natural killer (NK) receptors. In addition, in vitro studies were performed to identify candidate stimuli for NK receptor expression. RESULTS: In normal intestine, different proportions of IELs, which were mainly T cells, expressed the NK receptors CD94/NKG2, NKR-P1A, KIR2D/3D, NKp46, Pen5, or CD56. During the active phase of celiac disease, the frequency of CD94(+) IELs, which were mostly alphabeta T cells, was conspicuously increased over controls. In contrast, the expression of other NK markers was not modified. Furthermore, expression of CD94 could be selectively induced in vitro by T-cell receptor activation and/or interleukin 15, a cytokine produced by intestinal epithelial cells. CONCLUSIONS: The gut epithelium favors the development of T cells that express NK receptors. In active celiac disease, there is a specific and selective increase of IELs expressing CD94, the HLA-E-specific NK receptor that may be related to T-cell receptor activation and/or interleukin 15 secretion.

Adult↗
PubMed1999

Comparison of left ventricular mass and function in obese versus nonobese women <40 years of age.

We evaluated, through Doppler echocardiography, left ventricular (LV) mass and function in 82 obese young women (aged <40 years) who were asymptomatic, without any cardiovascular or pulmonary disease compared with a lean control group matched by age and height. LV mass, LV mass/height, and LV mass/volume were increased in obese women, and a lower LV E- and A-wave velocity ratio was noted, suggesting early cardiac involvement.

Adult↗
PubMed1999

A rat model presenting eosinophilia in the airways, lung eosinophil activation, and pulmonary hyperreactivity.

The aim of this study was to examine antigen-induced lung cell migration, eosinophil activation, and pulmonary reactivity of Wistar rats exposed to a new sensitization technique. The animals were sensitized with a single subcutaneous implant of a fragment of heat coagulated hen egg white and challenged 21 days later with an intratracheal injection of heat-aggregated ovalbumin (EWI). For comparison, another group of rats were sensitized by an intraperitoneal injection of ovalbumin in alum as adjuvant, with one booster on day 14 and challenge on day 21 post immunization (OVA/AL). Twenty-four hours after antigen challenge, the EWI group presented a higher number of eosinophils in the bronchoalveolar lavage (BAL) (4.85 +/- 1.43 x 10(6)) than the OVA/AL group (0.2 +/- 0.06 x 10(6)) or the control group, where the level of eosinophils were essentially undetectable. Levels of eosinophil peroxidase activity were increased in the cell-free BAL and homogenates of lung tissue in the EWI group (12.10 +/- 2.97 mg/mL and 36.14 +/- 7.21 ng/mg, respectively), but not in the OVA/AL group (4.83 +/- 1.4 ng/mL and 11.95 +/- 2.54 ng/mg, respectively), as compared with controls (5.16 +/- 1.65 ng/mL and 12.13 +/- 1.74 ng/mg, respectively). Thromboxane B2 levels were also increased in the BAL of EWI group (2.89 +/- 0.54 ng/mL) but not the OVA/AL group (1.13 +/- 0.23 ng/mL) as compared with controls (1.14 +/- 0.19 ng/mL). In contrast, the levels of prostaglandin E2 in the BAL were increased in both groups (456.4 +/- 11.8 pg/mL in the EWI group and 303.5 +/- 31.7 pg/mL in the OVA/AL group) as compared with controls (205.7 +/- 29.7 ng/mL). Moreover, only the EWI group developed increased pulmonary reactivity to serotonin (around two-fold), 24 hours after antigen challenge. The extent of lung eosinophil migration and activation and the pulmonary hyperreactivity induced by this novel sensitization procedure without adjuvants represents a significant improvement over existing experimental models of asthma.

Animals↗
PubMed1999

Practice patterns of international and U.S. medical graduate psychiatrists.

OBJECTIVE: The practice patterns of international medical graduate (IMG) and U.S. medical graduate (USMG) psychiatrists were compared. METHOD: Using data from the 1996 National Survey of Psychiatric Practice, the authors compared IMGs and USMGs in terms of demographic characteristics, practice settings, patients' clinical characteristics, and sources of reimbursement. RESULTS: The IMGs surveyed tended to be older than USMGs, included a higher proportion of women, and were more racially heterogeneous. They worked longer hours, worked more frequently in the public sector, and treated a higher proportion of patients with psychotic disorders. The IMGs also received a higher percentage of their income than USMGs from Medicaid and Medicare, whereas the reverse was true of self-payment. Most of these differences remained significant after psychiatrist's age, gender, race, board certification, and work setting were controlled for. CONCLUSIONS: IMG and USMG psychiatrists have different practice patterns. Policies that substantially decrease the number of IMG psychiatrists may adversely affect the availability of psychiatrists to treat minorities and other underserved populations.

Adult↗
PubMed1999

[Cardiac involvement in metabolic diseases].

OBJECTIVE: To evaluate cardiac involvement in children with metabolic disease in the out patient clinic of the Pediatric Cardiology Unit of Maria Pia Children's Hospital and their follow-up. MATERIAL AND METHODS: Twenty-nine medical records belonging to out patients with metabolic disease in consultation at our unit were reviewed. The following data from each record was analyzed: sex, metabolic disease diagnosis, age and motive for referral to a pediatric cardiology unit, cardiology diagnosis, therapy and evolution. RESULTS: Seventeen patients were boys and 12 girls. The average age of referral was 7.2 years (SD 4.8). The motives for referral were: screening for heart disease, 16; heart murmur, 7; congestive heart failure, 3; heart murmur and fatigue, 2; poor weight gain, 1. The following metabolic diagnoses were made: lysosomal diseases, 21; mitochondrial citopathies, 5; disorder of beta-oxidation of fatty acids, 2; carbohydrate deficient glycoprotein syndrome (CDG syndrome), 1. The cardiologic evaluation was normal in ten patients (4 with lysosomal disease, 4 with mitochondrial citopathy, one disorder of beta-oxidation of fatty acids, the CDG syndrome). Mitral and aortic valve lesions predominated in lysosomal diseases (12/21); myocardial involvement alone was present in two patients, and both myocardial and valvular lesions were present in three. Dilated cardiomyopathy was the presented manifestation in two patients-one with mitochondrial citopathy and one with a disorder of beta-oxidation of fatty acids. Three patients died and 26 remain out-patients. One patient was submitted to valve surgery. The average duration of follow-up was 21 months (SD 24). COMMENTS: Lysosomal diseases were the most representative in our patients, as described in the literature. Heart valve disease was the most frequent alteration. Indication for heart valve surgery is dependent on systemic involvement of the primary disease. All children with a metabolic disease with eventual heart involvement should be evaluated periodically by a cardiology unit. On the other hand, it is mandatory to screen a cardiomyopathy of unknown cause for a metabolic disease. The authors draw attention to the importance of infectious endocarditis prophylaxis in this group of patients.

Ambulatory Care Facilities↗
PubMed1998

Effect of exercise-induced ischemia on QT interval dispersion.

An increased spatial dispersion of ventricular repolarization duration (QT dispersion) is associated with an increased vulnerability to arrhythmias. This study was designed to examine the effect of exercise on QT dispersion in ischemic heart disease (IHD). QT dispersion, corrected QT dispersion, and percentage change in uncorrected and corrected QT dispersion between rest and peak exercise were examined in 14 members of a control group, 17 patients with IHD, and 14 patients with IHD who were receiving beta-blockers (IHD-B). All subjects had undergone a standard Bruce protocol exercise test, and QT intervals were measured at rest and peak exercise with a digitizing tablet interfaced to a personal computer. QT dispersion at rest was markedly increased in the IHD group compared with that in the control and IHD-B groups, respectively (corrected QT dispersion in milliseconds), 74 +/- 7, 40 +/- 4, 49 +/- 5, p < 0.03). The corrected QT dispersion at peak exercise was greater in the IHD group compared with that in the control group (57 +/- 5 vs 26 +/- 3 msec, p < 0.03). The percentage change in QT dispersion with exercise was significantly higher in the IHD group (52% +/- 5%) compared with that in both the control group (28% +/- 4%, p < 0.002) and the IHD-B group (30% +/- 3%, p < 0.01). A larger mean QT dispersion at peak exercise and an increased percentage change in QT dispersion with exercise may help explain the increased susceptibility of the IHD group for arrhythmias. The cardioprotective action of beta-blockers may be explained by their blunting effect on exercise-related changes in QT dispersion.

Adrenergic beta-Antagonists↗
PubMed1997

Ontogeny of the L-type voltage sensitive calcium channels in chick embryo retinospheroids.

The L-type voltage sensitive calcium channels (VSCC) of chick embryo retinospheroids were characterized during the development in vitro. Functionally, the activity of VSCC was characterized by continuously monitoring the changes in the intracellular free Ca2+ concentration (delta[Ca2+]i) with indo-1, in response to 30 mM KCl. The contribution of the L-type VSCC was evaluated using the L-type VSCC antagonist, nitrendipine. We also characterized the binding of [3H]nitrendipine to retinospheroid membranes during development, and determined the Kd and Bmax values. We observed that the changes in [Ca2+]i in response to 30 mM KCl increased from 159.46 +/- 6.62 nM at 0 days in vitro (DIV) retinospheroids to 704.4 +/- 59.9 nM at 14 DIV retinospheroids. Nitrendipine (2 microM) blocked the delta[Ca2+]i response by approximately 67% in all ages tested. No significant difference in the Kd values for the nitrendipine binding was observed during in vitro development of the retinospheroids. However, the Bmax increased from 27.99 +/- 1.95 fmol/mg protein in 0 DIV retinospheroids to 131.09 +/- 14.24 fmol/mg protein in 14 DIV retinospheroids, supporting the delta[Ca2+]i results. The results presented suggest that the increase in [Ca2+]i during development was due to an increase in the number of L-type channels. Therefore, the expression of L-type VSCC is developmentally regulated during retinogenesis in vitro and accompanies neuronal maturation, probably regulating the Ca2+ input crucial to the onset of important intracellular Ca2+-dependent functions.

Animals↗
PubMed1997

Management of bronchopleural fistula with a variable-resistance valve and a single ventilator.

Independent lung ventilation with two ventilators is sometimes used in the management of bronchopleural fistula (BPF). We describe a patient in whom gas flow through a large BPF was initially reduced, and subsequently eliminated, during differential lung ventilation using a single ventilator and a variable-resistance valve attached to one lumen of a bifurcated endotracheal tube.

Bronchial Fistula↗
PubMed1996

The topography of chromosomes and genes in the nucleus.

At present several lines of evidence indicate that the nucleus is functionally compartmentalized into discrete structures with defined properties. For instance, it is well established that the molecular machines involved in replication, transcription, and RNA processing assemble into morphological entities but it remains unclear whether these correspond to autonomous "organelles" or rather represent temporary accumulations of either active factors recruited onto DNA templates or inactive factors stored in the vicinity of genes. According to the latter view, the spatial distribution of genes during interphase should play a major role in the subnuclear organization of nonchromatin components such as replication, transcription, and processing factors, and in this article we discuss current ideas on the functional compartmentalization of chromosomes and genes within the nucleus.

Binding Sites↗