Biomedical subjects
Publications and source records attributed to C Escalante.
Fatigue is a commonly reported and observed symptom among patients at the University of Texas M.D. Anderson Cancer Center. Caring for patients with this debilitating symptom is a major challenge. The nurse practitioner in the Fatigue Clinic has a special role in the management of these patients.
BACKGROUND: Vertical banded gastroplasty (VBG) has been found to result in significant reduction in body mass index (BMI) during the first postoperative year. We investigated the impact of some intrinsic and extrinsic factors on long-term BMI evolution in morbidly obese patients who underwent VBG, with the aim of establishing a long-term weight-loss prognosis. METHODS: 67 consecutive morbidly obese patients who underwent VBG were followed for 2 years; of these, 34 were followed 3 more years, for a total follow-up of 5 years. BMI was monitored and correlated with demographic (preoperative BMI, obese relatives, age and gender) and lifestyle variables (physical activity, habitual dietary transgression and occupational status). RESULTS: Global BMI fell from 47.5 at the time of the intervention to 32.1 when patients were examined 12 months after surgery. From the second year, an upward trend was observed, and at 5 years, mean BMI was above 35, considered in the high-risk range. Modifiable variables affecting lifestyle have shown significantly favorable effects on BMI evolution. Among intrinsic variables, BMI before surgery and obese parents also affect long-term evolution. CONCLUSION: Different variables should be considered in order to establish a long-term weight-loss prognosis for each patient, thus making it possible to act more specifically on modifiable variables.
These guidelines propose a treatment algorithm in which patients are evaluated regularly for fatigue, using a brief screening instrument, and are treated as indicated by their fatigue level. The algorithm's goal is to identify and treat all patients with fatigue that causes distress or interferes with daily activities or functioning. Management of fatigue begins with primary oncology team members who perform the initial screening and either provide basic education and counseling or expand the initial screening to a more focused evaluation for moderate or higher levels of fatigue. At this point the patient is assessed for the five primary factors known to be associated with fatigue: pain, emotional distress, sleep disturbance, anemia, and hypothyroidism. If any of these conditions are present, it should be treated according to practice guidelines, and the patient's fatigue should be reevaluated regularly. If none of the primary factors is present or the fatigue is unresolved, a more comprehensive assessment is indicated--with referral to other care providers as appropriate. The comprehensive assessment should include a thorough review of systems, review of medications, assessment of comorbidities, nutritional/metabolic evaluation, and assessment of activity level. Management of fatigue is cause-specific when conditions known to cause fatigue can be identified and treated. When specific causes, such as infection, fluid and electrolyte imbalances, or cardiac dysfunction, cannot be identified and corrected, nonpharmacologic and pharmacologic treatment of the fatigue should be considered. Nonpharmacologic interventions may include a moderate exercise program to improve functional capacity and activity tolerance, restorative therapies to decrease cognitive alterations and improve mood state, and nutritional and sleep interventions for patients with disturbances in eating or sleeping. Pharmacologic therapy may include drugs such as antidepressants for depression or erythropoietin for anemia. A few clinical reports of the use of corticosteroids and psychostimulants suggest the need for further research on these agents as a potential treatment modalities in managing fatigue. Basic to these interventions, the effective management of cancer-related fatigue involves an informed and supportive oncology care team that assesses patients' fatigue levels regularly and systematically and incorporates education and counseling regarding strategies for coping with fatigue (Johnson, 1999), as well as using institutional fatigue management experts for referral of patients with unresolved fatigue.
We present a case of tuberculous meningitis in a patient with acute myelogenous leukemia. The patient was in complete remission; he had persistent lymphopenia and CD4+ T lymphocytopenia. Diagnosis was complicated by the chronic and subacute nature of symptoms; some originally thought to be secondary to depression and chemotherapy related toxicity. Treatment was further complicated by the unusual phenomenon of paradoxical progression of disease while on appropriate therapy. This case illustrates the importance of consideration of mycobacteriosis in the differential diagnosis of chronic unexplained fever complicating treatment for acute leukemia. The natural history and essential aspects of diagnosis and treatment of CNS tuberculosis are reviewed. The clinical significance of unexplained CD4+ T lymphocytopenia and chronic lymphopenia in patients with leukemia is also discussed.
PURPOSE: To evaluate the efficacy of a sodium fluoride (NaF)/silica/xylitol dentifrice compared with that of a positive control NaF/silica dentifrice on caries increments in school children over a 3-year period in an area without an optimal level of fluoride in the drinking water (mean level <0.1 ppm). MATERIALS AND METHODS: A 3-year, double-blind clinical caries study was conducted in 2,630 children initially aged 8-10 years at 17 schools in the San Jose, Costa Rica metropolitan area. Clinical dental examinations were performed at participating schools utilizing portable dental equipment. Caries evaluations employed conventional tactile/visual methodology consisting of artificial light, dental mirrors and single-edge #23 explorers. Children accepted into the study were stratified by age and sex into two balanced groups within each school, and randomly assigned to use either a positive control dentifrice containing 0.243% NaF/silica or a test dentifrice containing 0.234% NaF/silica/10% xylitol. Children were instructed to brush with the assigned dentifrice twice daily. Caries evaluations were conducted at baseline, 2 years, and 3 years. RESULTS: After 3 years, subjects using the 0.234% NaF/silica/10% xylitol dentifrice had statistically significantly reduced decayed/filled surfaces (DFS; -12.3% reduction; P < or = 0.001) and decayed/filled buccal and lingual surfaces (DFS-BL; -10.5% reduction; P < or = 0/01).
Mammalian aspartyl-tRNA synthetase (DRS) occurs in a multi-enzyme complex of aminoacyl-tRNA synthetases, while DRS exists as free soluble enzymes in bacteria and yeast. The properties of human DRS transient expressed in COS cells were examined. After transfection of COS cells with the recombinant plasmids pSVL-63 that contained hDRS cDNA coding and non-coding sequences, and pSV-hDRS where the non-coding sequences were deleted, DRS in the transfected COS cells significantly increased compared to mock transfected cells. COS cells transfected with pSV-hDRS delta 32 that contained N-terminal 32 residue-coding sequence deleted hDRS cDNA showed no increase in DRS activity. Northern blot analysis showed that concentrations of corresponding mRNAs of hDRS and hDRS delta 32 were greatly enhanced in transfected cells. The increases in the level of the transcripts were much higher than those of the corresponding proteins. Gel filtration analysis showed that hDRS in pSV-hDRS transfected cells expressed as a low molecular weight form of hDRS and pSV-hDRS delta 32 transfected cells did not. Epitope tagging and indirect immunofluorescence microscopy was used to localize hDRS. Both hDRSmyc and hDRS delta 32myc were localized in the cytoplasm and showed diffused patterns. These results showed that hDRS has little tendency to aggregate in vivo and suggested that the N-terminal extension in hDRS was not involved in the expression and sub-cellular localization of hDRS, but may play a role in the maintenance of enzymatic activity of hDRS in COS cells.
BACKGROUND: Hospitalization and intravenous (IV) broad-spectrum antibiotics are the standard of care for all febrile neutropenic patients with cancer. Recent work suggests that a low-risk population exists who might benefit from an alternate approach. METHODS: A prospective randomized clinical trial was performed comparing oral ciprofloxacin 750 mg plus clindamycin 600 mg every 8 hours with IV aztreonam 2 g plus clindamycin 600 mg every 8 hours for the empiric outpatient treatment of febrile episodes in low-risk neutropenic patients with cancer. RESULTS: The oral regimen cured 35 of 40 episodes (88% response rate), whereas the IV regimen cured 41 of 43 episodes (95% response rate, P = 0.19). Although the cost of the oral regimen was significantly less than that of the IV regimen (P < 0.0001), it was associated with significant renal toxicity (P < 0.05), which led to early termination of the study. Overall, combining its safety and efficacy, the IV regimen was superior (P = 0.03). CONCLUSIONS: This prospective study suggested that outpatient antibiotic therapy for febrile episodes in low-risk neutropenic patients with cancer is safe and effective. Better oral regimens are needed.
Mammalian aspartyl-tRNA synthetase occurs in the multienzyme complex of aminoacyl-tRNA synthetases, while bacterial and yeast aspartyl-tRNA synthetases exist as free soluble enzymes. Cloning and sequencing of mammalian aspartyl-tRNA synthetase revealed a newly evolved N-terminal 32-amino-acid sequence, which contains a putative amphiphilic helix (Jacobo-Molina, A., Peterson, R., and Yang, D. C. H. (1989) J. Biol. Chem. 264, 16608-16612). Human aspartyl-tRNA synthetase (hDRS) and an N-terminal 32-residue truncated form of human aspartyl-tRNA synthetase (hDRS delta 32) were expressed in Escherichia coli under the control of the inducible tac promoter as glutathione-S-transferase (GST) fusion proteins linked through a thrombin cleavage site. The GST-hDRS fusion protein and the GST-hDRS delta 32 were purified by affinity chromatography on glutathione-agarose and were fully active in aspartylation of mammalian tRNA. After cleavage of GST from the fusion proteins by thrombin, hDRS and hDRS delta 32 were purified by affinity chromatography on tRNA-Sepharose. Both hDRS and hDRS delta 32 were present as a mixture of monomeric and dimeric forms. GST-hDRS formed high molecular weight aggregates while GST-hDRS delta 32 was a dimeric protein. Both hDRS and hDRS delta 32 bound to hydrophobic interaction gels such as aminohexyl-agarose. In the absence of propylene glycol, hDRS bound to amino-hexyl-agarose weaker than hDRS delta 32, but, in the presence of 50% propylene glycol, hDRS bound tighter than hDRS delta 32. Both hDRS and hDRS delta 32 were fully active in aspartylation of mammalian tRNA and ATP-PPi exchange. In comparison to the N-terminal truncated form, the full-length enzyme showed greater thermal stability and ATP-PPi exchange activity but lower aminoacylation activity. The catalytic constant of hDRS delta 32 for aminoacylation of tRNA was 2-fold higher than that of hDRS. The Michaelis-Menten constants for aspartic acid and tRNAAsp were 302 microM and 13 nM for hDRS, and 29 microM and 130 nM for hDRS delta 32, respectively. These results suggest that the newly evolved N-terminal peptide in hDRS may modulate the enzymatic activity, the stability, and the chromatographic behavior of hDRS. The structure and function of the N-terminal peptide in aspartyl-tRNA synthetase and in the synthetase complex will be discussed.
Hypertensive crisis is an acute emergency requiring aggressive management. Its incidence has decreased in recent years but still is prevalent in the medical community. From review of past and present treatment regimens, the following recommendations can be considered. (1) In the treatment of malignant hypertension with associated CHF, sodium nitroprusside is still an excellent agent. It has a rapid onset of action and blood pressure can be easily titrated. Nitroglycerin is also another agent that can be used in this situation. (2) In the treatment of malignant hypertension with associated aortic dissection, trimethophan camsylate is the preferred agent. An alternative choice is the combination of nitroprusside and labetalol. (3) In the treatment of malignant hypertension with associated myocardial ischemia, an excellent choice is nitroglycerin. Labetalol also should be considered in this situation. (4) In the treatment of hypertension during pregnancy, hydralazine is still a good choice. Labetalol has also been shown to be efficacious. (5) In the treatment of malignant hypertension with associated cerebral ischemia, the following drugs should be considered: nitroprusside, nitroglycerin, and labetalol. The most important attribute of these agents is that they are nonsedating and rapid in onset. (6) In the treatment of postoperative hypertension the choices best suited are labetalol, enalapril, nitroprusside, and nitroglycerin. These agents are rapid in onset and all can be administered intravenously.