Cesium salt of tungstophosphoric acid/mesoporous (zirconia-silica) composite for highly efficient synthesis of 7-hydroxy-4-methyl coumarin and removal of methylene blue.

The removal of harmful organic dyes from aqueous solutions has drawn the attention of scientists because of the substantial threat they pose to society's worldwide health. Hence, it is crucial to design an adsorbent that is both very effective in removing dyes and has the benefit of being inexpensive. In the present work, Cs salts of tungstophosphoric acid (CPW) supported mesoporous Zr-mSiO2 (mZS) with varying extents of Cs ions have been prepared by a two-step impregnation technique. Accordingly, a lowering in the surface acidity modes was observed after Cs exchanged protons of H3W12O40 and formed salts immobilized on the mZS support. After exchanging the protons with Cs ions, the characterization results revealed that the primary Keggin structure was unaltered. Moreover, the Cs exchanged catalysts had higher surface area than the parent H3W12O40/mZS, suggesting that Cs reacts with H3W12O40 molecules to create new primary particles with smaller sizes possessing inter-crystallite centers with a higher dispersion degree. With an increase in Cs content and thus a decrease in the acid strength and surface acid density, the methylene blue (MB) monolayer adsorption capacities on CPW/mZS catalysts were increased and reached an uptake capacity of 359.9 mg g-1 for Cs3PW12O40/mZS (3.0CPW/mZS). The catalytic formation of 7-hydroxy-4-methyl coumarin was also studied at optimum conditions and it is found that the catalytic activity is influenced by the amount of exchangeable Cs with PW on the mZrS support, which is in turn influenced by the catalyst acidity. The catalyst kept approximately the initial catalytic activity even after the fifth cycle.

Cell confluency is as efficient as serum starvation for inducing arrest in the G0/G1 phase of the cell cycle in granulosa and fibroblast cells of cattle.

The cell cycle stage of donor cells is an important factor influencing developmental ability of nuclear transfer embryos. In the present experiment, cumulus and fibroblast cells of cattle were subjected to flow cytometric cell cycle analysis before being used in somatic cloning experiments. The following experimental groups were analyzed for each cell type: (1) actively dividing cells, (2) cells confluent for 4 days, (3) cells starved for 1, 2, 3 or 5 days. Using the propidium iodide flow cytometric assay, there were no significant differences (P > or = 0.05) in the percentage of cells in G0/G1 regardless of origin and type of cell, after confluency or serum starvation. Differences with the growing cells were found (P < or = 0.01). To determine what subset of cells in G0/G1 were in the G0 subphase of the cell cycle, an immunofluorescence analysis was conducted using monoclonal anti-PCNA antibodies in a FACS assay. There were not statistically significant differences in the percentage of cells that enter G0, between confluent and any starved group for either type of cells. Bovine fibroblast cells, confluent or serum starved for 3 days, were used in nuclear transfer experiments. A slight trend for a more desirable fusion rate in starved cells was detected, and embryo cleavage was greater in starved cells, however, in vitro development to blastocysts was similar between groups. Data indicate that prolonged culture of cells in the absence of serum does not imply a shift in the percentage of cells that enter G0/G1 or G0 alone, and that confluency is sufficient to induce quiescence. This finding can be beneficial in nuclear transfer programs, because there are negative effects such as apoptosis, associated with serum starvation.

Effect of cryopreservation on fusion efficiency and in vitro development into blastocysts of bovine cell lines used in somatic cell cloning.

The outcome of the process of cloning by nuclear transfer depends on multiple factors that affect its efficiency. Donor cells should be carefully selected for their use in somatic nuclear transfer, and the protocols used for keeping frozen cell banks are of cardinal importance. Here we studied the effect of two protocols for freezing donor cells on fusion rate and development into blastocysts. Our hypothesis is that freezing affects cell membranes in a way that interferes with the fusion process upon cloning but without hampering normal cell development in vitro. We found that freezing cell lines without controlling the cooling rate gives lower yields in the fusion step and in the final development into blastocysts, compared with cells frozen with a controlled cooling rate of approximately 1 degrees C/min. Transmission electron microscopy of the cells subjected to different freezing procedures showed major damage to the cells frozen with a non-controlled protocol. We conclude that freezing of donor cells for cloning is a critical step in the procedure and should be monitored carefully using a method that allows for a step-wise, controlled cooling rate.

Assessing the new general competencies for resident education: a model from an emergency medicine program.

The Accreditation Council for Graduate Medical Education (ACGME) has promoted six areas that should be addressed during graduate medical training, or "general competencies" (GCs). According to the ACGME, these GCs should be reflected in the educational processes of all residency programs. In promulgating these competencies, however, the ACGME has not provided examples of core content, methods of implementation, or methods of evaluation. The authors propose a practical method for modifying an existing evaluation format, providing a template other programs could use in assessing residents' acquisition of the knowledge, skills, and attitudes reflected in the GCs.

Adenosine-induced ventricular fibrillation.

The use of adenosine has been suggested as a diagnostic tool in the evaluation of wide ORS complex tachycardia. However, adenosine shortens the antegrade refractoriness of accessory atrioventricular connections and may cause acceleration of the ventricular rate during atrial fibrillation. We observed ventricular fibrillation in 2 patients who presented to the emergency department with pre-excited atrial fibrillation and were given 12 mg of adenosine.

Training tomorrow's clinicians today--managed care essentials: a process for curriculum development.

OBJECTIVE: To develop a managed care curriculum for primary care residents. DESIGN: This article outlines a 4-stage curriculum development process focusing on concepts of managed care organization and finance. The stages consist of: (1) identifying the curriculum development work group and framing the scope of the curriculum, (2) identifying stakeholder buy-in and expectations, (3) choosing curricular topics and delivery mechanisms, and (4) outlining the evaluation process. Key elements of building a curriculum development team, content objectives of the curriculum, the rationale for using problem-based learning, and finally, lessons learned from the partnership among the stakeholders are reviewed. RESULTS: The curriculum was delivered to an entering group of postgraduate-year 1 primary care residents. Attitudes among residents toward managed care remained relatively negative and stable over the yearlong curriculum, especially over issues relating to finance, quality of care, control and autonomy of practitioners, time spent with patients, and managed care's impact on the doctor-patient relationship. Residents' baseline knowledge of core concepts about managed care organization and finance improved during the year that the curriculum was delivered. Satisfaction with a problem-based learning approach was high. CONCLUSION: Problem-based learning, using real-life clinical examples, is a successful approach to resident instruction about managed care.

Transgenic rabbits for the production of biologically-active recombinant proteins in the milk.

The use of live bioreactors for the expression of human genes in the mammary gland of transgenic animals is one of the most cost-effective ways for the production of valuable recombinant therapeutic proteins. Among the transgenic species used so far, rabbits are good candidates for the expression of tens to hundreds of grams of complex proteins in the milk during lactation. The lactating mammary gland of rabbits has proven to be effective in the processing of complex proteins. In this work. the potential use of rabbits as bioreactors is discussed based on our results and the published data.

Safety Evaluation of Transgenic Tilapia with Accelerated Growth.

Recent advances in modern marine biotechnology have permitted the generation of new strains of economically important fish species through the transfer of growth hormone genes. These transgenic fish strains show improved growth performance and therefore constitute a better alternative for aquaculture programs. Recently, we have obtained a transgenic tilapia line with accelerated growth. However, before introducing this line into Cuban aquaculture, environmental and food safety assessment was required by national authorities. Experiments were performed to evaluate the behavior of transgenic tilapia in comparison to wild tilapia as a way to assess the environmental impact of introducing transgenic tilapia into Cuban aquaculture. Studies were also conducted to evaluate, according to the principle of substantial equivalence, the safety of consuming transgenic tilapia as food. Behavior studies showed that transgenic tilapia had a lower feeding motivation and dominance status than controls. Food safety assessment indicated that tilapia growth hormone has no biological activity when administered to nonhuman primates. Furthermore, no effects were detected in human healthy volunteers after the consumption of transgenic tilapia. These results showed, at least under the conditions found in Cuba, no environmental implications for the introduction of this transgenic tilapia line and the safety in the consumption of tiGH-transgenic tilapia as an alternative feeding source for humans. These results support the culture and consumption of these transgenic tilapia.

A mutant streptokinase lacking the C-terminal 42 amino acids is less immunogenic.

Streptokinase (SK) is the most widely used compound for the treatment of myocardial infarction and the least expensive thrombolytic agent, but a drawback to its use is the widespread presence of anti-SK antibodies (Abs). Clinical failure of the activation of the fibrinolytic system by SK has been reported due to the presence of a high titer of anti-SK neutralizing Abs. Patients receiving SK therapy develop high anti-SK antibody titers, which might provoke severe allergic reactions. These Abs are sufficient to neutralize a standard dose of SK up to four years after initial SK administration. This is a clinical problem because of the increasing number of patients who have been treated once with SK for acute myocardial infarction (AMI) and are likely to require plasminogen activator treatment in the future. In previous in vitro studies, we have shown that a deletion mutant (mut-C42), lacking the 42 C-terminal residues, was significantly less antigenic when compared with the native molecule (SKC-2). In this study, 14 monkeys were subjected to treatment with SKC-2 and mut-C42 in order to compare their humoral response by determining SK neutralizing activity in monkey's sera. All monkeys developed anti-SKC-2 Ab titers, but in the case where treatment induced Abs directed against the C-terminus of SKC-2, neutralizing activity against the native protein was significantly higher than that developed against mutant SK mut-C42.

Dual approval of a residency program: ten years' experience and implications for postdoctoral training.

In 1985, the American Osteopathic Association (AOA) changed its educational policies to permit osteopathic postdoctoral programs in settings that were accredited by the Accreditation Council for Graduate Medical Education (ACGME). In response to this policy change, an existing ACGME-accredited emergency medicine residency was modified to create a combined osteopathic/allopathic residency program that meets the educational requirements of both the AOA and the ACGME. Our 10-year experience with this combined osteopathic/allopathic emergency medicine residency is described in terms of program development, governance structure involving key stakeholders, faculty distribution--equal numbers of allopathic and osteopathic faculty, and educational outcome of the total number of residents graduated (93 graduates, with 33 osteopathic physicians and 60 allopathic physicians). Lessons learned from the 10 years' experience of this combined residency program, as well as current issues, are explained. The future potential of such dual-approved programs on the supply of residency positions is discussed from the viewpoint of osteopathic postdoctoral education.

QT dispersion may be a useful adjunct for detection of myocardial infarction in the chest pain center.

BACKGROUND: QT dispersion has been proposed as a noninvasive measurement of the degree of inhomogeneity in myocardial repolarization. Increased QT dispersion has been reported after myocardial infarction. We hypothesized that increased QT dispersion may be a useful adjunct for risk stratification in patients being evaluated in a chest pain center. METHODS AND RESULTS: Patients were admitted to the chest pain center for evaluation of chest pain. Exclusion criteria included (1) systolic blood pressure <90 mm Hg, (2) ischemia or infarction on the initial electrocardiograph (ECG), (3) elevated creatine kinase or MB fraction, and (4) chest pain associated with cocaine use. Serial creatine kinase and MB levels and ECGs were obtained at 0, 6, and 9 hours. Patients were monitored for (1) creatine kinase and MB rise, (2) ECG changes for infarction, (3) ST-segment changes, and (4) rest angina. A negative evaluation at the chest pain center led to an exercise stress test. Patients with a positive exercise stress test were admitted for further evaluation and patients with a negative exercise stress test result were discharged home. Patients were divided into 3 groups. Group 1 consisted of patients who were found to have an acute myocardial infarction (AMI), group 2 consisted of patients with prior history of coronary artery disease but no evidence of AMI, and group 3 consisted of patients without prior coronary artery disease or AMI. QT dispersion was measured on the initial ECG in all patients. A total of 586 patients were evaluated. Group 1 consisted of 13 patients with mean QT dispersion of 44.6+/-18.5 ms, group 2 consisted of 267 patients with a mean QT dispersion of 10.0+/-13.8 ms, and group 3 consisted of 303 patients with a mean QT dispersion of 10.5+/-10.0 ms. Analysis of variance showed a significantly higher QT dispersion in patients who had AMI compared with other patients with chest pain (P< .001). CONCLUSIONS: QT dispersion can be a useful diagnostic adjunct for detection of AMI in patients with chest pain with a normal ECG and normal cardiac enzymes.

Emergency management of acute myocardial infarction. Focus on pharmacologic therapy.

Treatment of acute myocardial infarction has evolved significantly in the past two decades. Reperfusion therapies of thrombolysis and percutaneous angioplasty are major advances that can be employed to save infarcting myocardium and reduce mortality. When reperfusion therapy is combined with the use of aspirin, beta-blockade, heparin, and nitroglycerin, the emergency management of the patient with myocardial infarction can be completed. Outcomes in patients are determined by what happens in the first few minutes to hours after onset, and any delay in diagnosis or treatment may have significant consequences. This article reviews intervention and treatment strategies for acute myocardial infarction.

Evaluation of syncope in the emergency department.

Although most cases of syncope are benign, an adequate evaluation, which begins in the emergency department, is required to exclude life-threatening disorders. In addition, life-threatening disorders such as QT prolongation as well as confounding alternative diagnoses (e.g., seizure disorder) are also discussed.

[The nutritional-viral etiology of epidemic neuropathy. The Group for the Study of Epidemic Neuropathy]. / Etiología nutro-viral de la neuropatía epidémica. Grupo para el estudio de la neuropatía epidémica.

Viral sequences of the cerebrospinal fluid were amplified by using oligonucleotides that are homologous to region 5' of the Enteroviruses. The results showed a great variability in the amplified sequences, suggesting the presence of enteroviral quasispecies with altered biological properties in the stressed individuals that may play an important role in the neurological damage.

Clinical practice guidelines: a review.

The development of clinical practice guidelines has spread from utilization review agencies to physician specialty societies, federal agencies, managed care organizations, and academic health centers as their usefulness in accomplishing the goals of healthcare reform become clear. The author reviews the mounting evidence that variation in the practice of medicine suggests that patients in some areas are not receiving all needed services, while others are receiving unnecessary services. He explores the implications of practice guidelines for improving the quality of care while controlling cost. Practice guidelines are defined and distinguished from medical review criteria. The author explores the challenges in governance, funding, and guideline development and communication that will have to be overcome to establish the credibility of practice guidelines. Finally, he addresses the opportunities for the osteopathic medical profession to establish its uniqueness in this setting.

Ultrastructural and immunocytochemical characteristics of hepatocytes from hepatitis B virus infected chimpanzees.

Liver tissue samples from four chimpanzees submitted to viral challenge in order to test a recombinant anti-hepatitis B virus vaccine, were studied by electron microscopy. The vaccinated monkeys showed no evidences of acute viral hepatitis (AVH), demonstrating the protection against an infective viral dose; on the contrary, the non-vaccinated chimps developed signs of AVH in hepatocytes such as: different size and shape, slight dilatation of the rough endoplasmic reticulum, disappearance of the mitochondrial crests, broadening of the normal space between the membranes of the nuclear coating and presence of laminar bodies and cytoplasmic vacuoles. Furthermore, the presence of the hepatitis B virus surface (HBV) antigen was confirmed in non-vaccinated monkeys using immunocytochemical techniques. Transmission electron microscopy and immunocytochemical analysis corroborated the protective effect of the recombinant vaccine against the HBV in the vaccinated animals.

'Blueprint' for creating classroom facilities in teaching hospitals.

Classroom facilities in teaching hospitals have evolved from simple rooms with blackboards to sophisticated amphitheaters with high-tech audiovisual equipment. This article presents a "blueprint," which was used in an osteopathic hospital, to renovate existing space into classrooms that are conducive to learning.

Traumatic rupture of right mainstem bronchus in a child.

We report a case of a 7-year-old boy who sustained a ruptured right mainstem bronchus in a motor vehicle accident. The clinical presentation, pathophysiology, and diagnosis of tracheobronchial injuries secondary to nonpenetrating thoracic trauma are discussed.