Biomedical subjects
Publications and source records attributed to A Rodriguez.
A soil-inhabiting Fusarium proliferatum strain was capable of transforming or degrading nonlabeled and (sup14)C-labeled industrial, natural, and synthetic lignin. The mineralization rate per day (expressed as the percentage of added radioactivity recovered as to (sup14)CO(inf2)) was maximal during primary metabolism.
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Juvenile X linked retinoschisis (RS) is a bilateral vitreoretinal dystrophy that develops early in life. Previous linkage studies have localised the RS gene to Xp22.1-p22.3 between DXS207 and AFM 291Wf5, which represents a genetic distance of approximately 3.7 cM. In an effort to facilitate the eventual cloning of the RS gene, we have analysed a large Colombian family, using 10 microsatellite markers that have been mapped to the region Xp22.1-p22.3. A total of 93 members, including 19 affected and eight unaffected males, two affected females, and six obligate carrier females were analysed. Close linkage was observed between the disease locus and DXS999 (Zmax = 2.27, theta max = 0.05), DXS987 (Zmax = 2.61, theta max = 0.1), DXS443 (Zmax = 4.23, theta max = 0.1), and DXS274 (Zmax = 3.49, theta max = 0.05) markers. Recombination with the RS locus was found for all marker loci except DXS197, DXS43, and DXS1195. These results place the RS locus within an interval of approximately 2 cM between the flanking markers DXS1053 and DXS999, approximately 1.7 cM closer than the previously reported boundary. The results also further confirm the lack of genetic heterogeneity of RS.
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A psycho-social study was performed in 19 Colombian families with 40 affected individuals with Usher syndrome, identified through our national screening program for this disease in Colombia. The study was aimed to understand their needs, kind of familial inter-relationships, and social and familial implications of the patients' double sensorial limitation, in order to provide enough information to support the importance of early diagnosis, appropriate genetic counseling, and the establishment of adequate educational and rehabilitation programs in Colombia.
Non-infectious virus-like particles of SIVsmB7 that expresses env and gag gene products but are defective in pol and vpx/vpr were assessed for their ability to induce protective immunity against infection with pathogenic SIVsmE660 in rhesus macaques. Animals were immunized in three groups: group A was primed with cell-associated SIVsmB7 and boosted with cell-free SIVsmB7; group B was primed with cell-free SIVsmB7 and boosted with cell-free SIVsmB7 conjugated to iron oxide microbeads; group C was primed with cell-free SIVsmB7 mixed with Titer Max adjuvant and boosted with cell-free SIVsmB7 mixed with SAF-M adjuvant followed by secondary boosting with cell-free SIVsmB7 conjugated to microbeads. Animals were challenged intravenously with 20 animal infectious doses of SIVsmE660 grown in rhesus peripheral blood mononuclear cells 3 weeks after final boosting. All animals became infected as evidenced by quantitative virus cultivation. Sera from immunized animals contained low-titer antibodies by ELISA and low or undetectable neutralizing antibodies on the day of challenge but strong anamnestic antibody responses were observed following challenge. Interestingly, 2 of 3 animals in group A showed evidence of transient viremia and more stable CD4 counts following challenge as compared to the other immunized animals and to non-immunized controls. Thus, immunization with cell-associated SIVsmB7 did not provide sterilizing immunity against challenge with a highly pathogenic SIV strain but might have caused virus clearance later in infection.
OBJECTIVES: This study sought to determine whether the response to amrinone in patients with severe baseline left ventricular dysfunction can predict improvement in left ventricular ejection fraction after coronary artery bypass graft surgery. BACKGROUND: Previous studies have suggested that the inotropic response to dobutamine can identify viable myocardium in the setting of chronic coronary disease and left ventricular dysfunction. However, increased oxygen demand stimulated by dobutamine can lead to superimposition of ischemia on the hibernating state, potentially confounding interpretation of results. Amrinone is an inotropic agent that does not critically augment myocardial oxygen demand and may be useful for identification of hibernating myocardium in the chronically ischemic state. METHODS: Forty-four consecutive patients with coronary artery disease and left ventricular ejection fraction < 40% referred for coronary artery bypass graft surgery underwent amrinone stimulation (1 mg/kg body weight). Left ventricular ejection fraction was determined before amrinone stimulation, 20 min after infusion and 21 days after bypass surgery. RESULTS: Baseline ejection fraction was 28 +/- 7% (mean +/- SD). Ejection fraction increased to 35 +/- 5% after amrinone stimulation (p < 0.0001) and to 33 +/- 6% after bypass surgery (p < 0.0001). Postbypass ejection fraction was significantly correlated with postamrinone ejection fraction (r = 0.65, p < 0.0001). Furthermore, the change in ejection fraction from baseline to after bypass surgery was highly correlated with the change in ejection fraction after amrinone stimulation (r = 0.75, p < 0.0001). Of 13 patients with an increase in ejection fraction > or = 10% after amrinone, all 13 had an increase of at least 8% and 11 (85%) of 13 had an increase > or = 10% after bypass surgery. In contrast, of 31 patients with an increase in ejection fraction < 10% after amrinone, only 2 (6%) had an increase > or = 10% (p < 0.0001) and 28 (90%) of 31 had an increase < 5% after bypass surgery. CONCLUSIONS: Augmentation of myocardial contraction by amrinone in patients with chronic coronary artery disease and severe baseline left ventricular dysfunction predicts improvement in left ventricular ejection fraction after coronary artery bypass graft surgery.
The growth stimulatory effects of interleukin-3 (IL-3) on normal hematopoietic progenitor cells are well established, and clinical trials using IL-3 after bone marrow transplantation for various malignancies including lymphomas are frequently conducted. Although the IL-3 receptor is expressed on the surfaces of follicular small cleaved-cell lymphoma (FSCCL) cells, the in vivo effects of IL-3 on FSCCL have not been studied previously. Because our preclinical data suggested that IL-3 may have dose-dependent inhibitory effects on FSCCL cells in vitro, we treated eight FSCCL patients with high-dose IL-3 in an outpatient setting. Each patient received 1 mg/m2 of IL-3 subcutaneously daily for 14 days followed by 7 days without IL-3. After three courses (9 weeks), the patients were evaluated for clinical responses. One patient had a minor response, and four had no responses. Three patients who had progressive disease before IL-3 treatment continued to have progressive disease. In two patients with bone marrow involvement with lymphoma, IL-3 had no effect on FSCCL cells. One patient with peripheral blood involvement with FSCCL cells that expressed IL-3 receptors had temporary growth arrest of the circulating malignant cells. IL-3 significantly increased the absolute neutrophil count in seven patients (87%) but had little effect on the number of normal circulating B cells. There was an increase in the number of circulating natural killer cells and CD8+ cells in four patients. Treatment was very well tolerated; no life-threatening toxicities were observed. The most common toxicities were injected conjunctivae (100%), fever (100%), fatigue (87%), and skin rash (75%). Most of the side effects subsided with the continued use of IL-3. These preliminary results suggest that high-dose IL-3 does not stimulate the growth of FSCCL cells in vivo and, in some instances, may cause growth inhibition.
Tellinid clams Macoma balthica were sampled every 2 months for 2.5 years at two locations from the Westerschelde estuary (The Netherlands) and submitted to in vitro short-term exposure to Cd, Cu and Zn. Total and heat-stable cytosolic metal concentrations have been measured before and after exposure to study the effects of the sampling season on metal uptake by the bivalve. We observed much higher uptakes of Cd and, to a lesser extent, Cu in winter than in summer, while Zn appears to be constantly regulated. These phenomena are amplified in the cytosol, especially for Cd, a non-essential element, for which the concentrations after exposure can reach 3.5-4 microg x g-1 (dry wt.) in winter, but only a maximum of 0.5 microg x g-1 in summer, all natural values being between 0.01 and 0.1 microg x g-1 on average. The contents (microg) of the various elements, either at the total or at the cytosolic level, are not constant, hence showing that the seasonal body weight fluctuation of the clams (dilution or concentration effect) is not the only parameter responsible for the metal uptake variability. Furthermore, we have shown that the proportion of cytosolic metal is not constant, but increases with the absolute cytosolic concentration up to 35-40%. Therefore, the cytosolic phase of the cells plays a growing role in Cd, Cu and Zn storage as long as their total concentration increases.
OBJECTIVE: To analyze the referral patterns and diagnosis of uveitis during the past decade in a large tertiary eye center. DESIGN: The records of 1237 patients with uveitis referred to the Immunology Service of the Massachusetts Eye and Ear Infirmary from 1982 to 1992 were classified and analyzed. Data regarding sex, race, nationality, referral site, ages at presentation and onset of uveitis, ocular involvement, clinical characteristics, ocular condition, and systemic disease associations were obtained. RESULTS: The mean age at onset of uveitis was 37.2 years; the male-to-female ratio was 1:1.4. Most patients were white (85.8%), born in the United States (83.1%), and referred from within New England (84.7%). Anterior uveitis was most common (51.6%), followed by posterior uveitis (19.4%), panuveitis (16.0%), and intermediate uveitis (13.0%). Chronic (58.3%), nongranulomatous (77.7%), and noninfectious (83.1%) were the most frequent types of uveitis. The most common entities included idiopathic (34.9%), seronegative spondyloarthropathies (10.4%), sarcoidosis (9.6%), juvenile rheumatoid arthritis (5.6%), systemic lupus erythematosus (4.8%), Behçet's disease (2.5%), and the acquired immunodeficiency syndrome (2.4%). CONCLUSION: The appearance of new uveitic entities, such as the acute retinal necrosis syndrome, multifocal choroiditis and panuveitis, birdshot retinochoroidopathy, and acquired immunodeficiency syndrome-related uveitis, and the reemergence of the classic infectious causes of uveitis, tuberculosis and syphilis, have changed the way we approach the diagnosis and management of posterior and panuveitis at the Massachusetts Eye and Ear Infirmary.
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We measured class-specific antibodies to the mycobacterial hsp70 protein in 67 patients with diabetes mellitus (27 type 1 and 40 type 2) with or without vascular complications. Using ELISA, the levels of IgG and IgM antibodies in the sera of diabetic patients did not significantly differ either from those of healthy control subjects or between both types of diabetes, regardless of gender, disease duration, HbA1 level, or type of vascular complication. In patients with type 2 diabetes, the mean serum IgA levels were significantly higher than those in their matched controls [274(71) mg/dl vs 208(88) mg/dl; P < 0.01]. In this group of patients, the IgA antibody titer was significantly correlated to the serum IgA level (r = 0.334; P < 0.01). Serological autoimmunity (IgG or IgM type) to hsp70 protein is common in both the normal and the diabetic population. The increased IgA levels and anti-hsp70 IgA titers in the sera of diabetics suggest a possible role of IgA in the pathogenesis of the vascular complications of diabetes mellitus.
In a prospective study of bacteremia caused by organisms of the Streptococcus milleri group a total of 32 adult patients were observed over a seven-year period. These patients accounted for 1.6% of all patients diagnosed as having significant bacteremia and 17% of all cases of streptococcal (nonpneumococcal) bacteremia diagnosed during the study period. Only five patients had polymicrobic bacteremia. In 31 cases, a presumed origin of infection was identified, generally oral or gastrointestinal disease. There were only six cases of nosocomial acquisition. The most common presenting symptom was prolonged fever. The following forms of presentation were documented: bacteremia with local suppurative infection (56%), bacteremia without local suppurative infection (25%), and endocarditis (19%). An associated focus of infection was found in the abdominal cavity in 20 cases (62%). The mortality rate was 12.5%. All isolates were susceptible to penicillin. Caution is necessary in interpreting a blood culture positive for Streptococcus milleri group organisms, since, unlike other viridans streptococci, they are rarely contaminants. For this reason patients with suppurative processes and/or digestive tract disease must be carefully investigated.
OBJECTIVE: To evaluate the association between maternal weight gain patterns, based on pregravid body mass index (BMI) and birth weight outcome in twins, and to make specific recommendations for maternal weight gain during twin gestation. METHODS: One hundred eighty-nine twin pregnancies were reviewed retrospectively. Weekly rates of maternal weight gain before 20 weeks, from 20 weeks to delivery, and for total gestation were calculated. Thresholds of weekly maternal weight gain were determined for underweight and normal-weight women. RESULTS: In underweight women, a higher weekly rate of gain before 20 weeks was associated with the birth of both twins weighing at least 2500 g (1.13 versus 0.70 lb/week, P = .017), when compared with mothers of at least one twin weighing less than 2500 g. A higher rate of weight gain from 20 weeks to delivery was associated with the delivery of twins weighing at least 2500 g in both underweight (1.92 versus 1.29 lb/week, P = .031) and normal weight (1.63 versus 1.29 lb/week, P = .046) women. No significant differences in weight gain patterns were found between overweight women delivering twins weighing less than 2500 g or at least 2500 g. A weekly rate of gain from 20 weeks' gestation to delivery of at least 1.75 lb/week in underweight women and at least 1.50 lb/week in normal-weight women was associated with the birth of both twins weighing at least 2500 g. After controlling for other potential determinants of birth weight, the threshold of 1.75 lb/week in underweight women showed a trend toward significance as an independent predictor of both twins weighing at least 2500 g (P = .06). CONCLUSION: Certain maternal weight gain patterns during twin pregnancy are associated with the birth of each twin weighing at least 2500 g. As with singletons, recommendations for maternal weight gain during twin pregnancy can be based on pregravid BMI.
OBJECTIVES: The purpose of this study was to report the 3-year follow-up results of the ERACI trial (Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Artery Bypass Surgery in Multivessel Disease). BACKGROUND: Although coronary angioplasty has been used with increased frequency in patients with multivessel coronary artery disease, its value, compared with bypass graft surgery, has not been established. Thus, controlled, randomized clinical trials such as the ERACI are needed. METHODS: In this trial 127 patients who had multivessel coronary artery disease and clinical indication of myocardial revascularization were randomized to undergo coronary angioplasty (n = 63) or bypass surgery (n = 64). The primary end point of this study was event-free survival (survival with freedom from myocardial infarction, angina and new revascularization procedures) for both groups of patients at 1, 3 and 5 years of follow-up. RESULTS: Freedom from combined cardiac events (death, Q-wave myocardial infarction, angina and repeat revascularization procedures) was significantly greater for the bypass surgery group than the coronary angioplasty group (77% vs. 47%; p < 0.001). There were no differences in overall (4.7% vs. 9.5%; p = 0.5) and cardiac (4.7% vs. 4.7%; p = 1) mortality or in the frequency of myocardial infarction (7.8% vs. 7.8%; p = 0.8) between the two groups. However, patients who had bypass surgery were more frequently free of angina (79% vs. 57%; p < 0.001) and required fewer additional reinterventions (6.3% vs. 37%; p < 0.001) than patients who had coronary angioplasty. CONCLUSIONS: 1) Freedom from combined cardiac events at 3-year follow-up was greater in patients who had bypass surgery than in those who had coronary angioplasty. 2) The coronary angioplasty group had a higher incidence of recurrence of angina and the need for repeat revascularization procedures. 3) Cumulative cost at 3-year follow-up was greater for the bypass surgery group than for the coronary angioplasty group.
The above discussion brings together a vast body of data that together proclaim with fervent clarity: Traumatic injuries are expensive. The expense is paid in productive lives lost, in permanent disability, in pain and suffering, and in health care resources consumed. As local and regional trauma systems struggle for development and survival, competition for the health care dollar casts in the additional necessity of providing the service of trauma care with maximum efficiency. Despite the variety of cost-efficiency measures described above, a majority of trauma centers continue to operate "in the red." Such cannot continue indefinitely. Fiscal responsibility dictates that health care institutions must balance budgets in order to maintain operations. Four primary strategies for cost containment appear from the above discussion: 1. Improve reimbursement rates from trauma patients. 2. Increase outside funding from government sources. 3. Improve cost efficiency of diagnostic and therapeutic procedures used in trauma patient management. 4. Increase efforts aimed at primary prevention of intentional and unintentional injuries. In the final analysis, most authors agree that the last strategy offers the best hope. As stated in their article, "The Economic Impact of Injuries," Harlan and colleagues conclude that "the most effective medical and cost reduction strategy would be prevention." The same article goes on to detail how greater funding for research into optimal prevention modalities could reap societal and economic benefits far beyond the value of the initial outlay. Yet such research funding continues to be inadequate. For every dollar spent on medical care of cancer patients, nine cents is directed to research. For every dollar spent on trauma care, less than a penny is spent on research. Until the public recognizes the terrible toll trauma extracts in lives, livelihood, and money wasted and until it realizes the pre-eminent importance of prevention, care of the trauma patient cannot truly achieve cost efficiency.
Duodenal trauma, with early diagnosis and prompt treatment, can be managed effectively by simple surgical techniques. Severe duodenal injuries and those associated with major destruction of adjacent structures (the pancreaticobiliary complex or abdominal vessels) require a more thoughtful strategy that incorporates a careful consideration of the physiologic stability of the patient and the extent of local destruction. Figure 8 summarizes these concepts in an algorithm.