Publications by authors named "SCHAFFER M"

A simple rapid method was developed for counting Escherichia coli in sea water using a membrane filter procedure. Following filtration the membrane filter was incubated on mFC agar medium for 24 +/- 2 h at 44.5 +/- 0.

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Although the pulmonary circulation in infants with advanced bronchopulmonary dysplasia (BPD) is characterized by abnormal structure and vasoreactivity, metabolic lung functions have not been studied in these infants. To test the hypothesis that patients with severe BPD may have abnormal metabolic lung function, we assessed the pulmonary vascular extraction of circulating norepinephrine in six children with BPD during cardiac catheterization. Plasma norepinephrine levels were measured from simultaneously drawn mixed venous (main pulmonary artery) and left atrium or femoral artery samples.

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The experience at the University of Colorado with the St. Jude Medical cardiac valve was reviewed to determine the feasibility of placing this prosthesis in children and the role of anticoagulation. A St.

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Supine exercise equilibrium radionuclide right ventriculography was performed in 13 children (8-18 years) with hypercholesterolemia. Phase analysis was used to construct right ventricular regions of interest, and a peri-right ventricular region was used for background correction. Right ventricular ejection fraction at rest and exercise was 50.

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We have identified a class of spinach plastid tRNA genes which do not require 5' upstream promoter elements for their expression in a chloroplast transcription system. The 5' DNA sequences flanking the trnR1 and trnS1 coding regions have little or no homology to previously characterized chloroplast promoter sequences. The deletion of the 5' DNA sequences from these genes to positions close to the start of the coding regions has little effect on their transcription in vitro.

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Aortoventriculoplasty was performed in 16 children between July, 1980, and July, 1984. Indications for the procedure were 1) aortic stenosis or insufficiency, or both, necessitating replacement of an aortic valve whose anulus would not accept a 19 mm diameter valve, (2) replacement of a small valve prosthesis, or (3) recurrent tunnel subaortic stenosis. Patients were 5 months to 17 years old at operation, 14 had previous repairs, and four had prior aortic valve replacement.

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Pseudomonas aeruginosa elaborates a number of extracellular products which have been shown to play a role in the pathogenesis of disease caused by this organism. In this study, we showed that the host environment markedly affects the levels of exoproducts produced. We compared the phenotypes of a number of P.

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Structures of the second adipokinetic hormones (AKH II's) from three locust species have been assigned by fast atom bombardment mass spectrometry. The AKH II hormone is identical in two Schistocerca species, S. nitans and S.

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A newborn with critical aortic stenosis and anular hypoplasia was treated with an aortic valvotomy using inflow occlusion. Five months later, important valvular insufficiency and residual stenosis necessitated aortic valve replacement. An aortoventriculoplasty using a 19 mm St.

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Staphylococcus aureus counts from swimming pool water were determined by the membrane filtration technique. Water samples were passed through a membrane filter and then put on Baird-Parker media. After incubation, the filters were transferred to nutrient agar, and incubated at 37 degrees C, for 3 h.

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With the recent advances in pediatric cardiology and cardiovascular surgery, assessment of ventricular function in single ventricle complexes is becoming increasingly important. The serial assessment of ventricular function helps our understanding of the natural and unnatural history in these patients. Equilibrium radionuclide ventriculography is safe, easy to perform, and well-suited to the serial assessment of ventricular function.

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M-Mode echocardiography was performed in 22 normal children and 22 children with ventricular septal defects. Left ventricular and left atrial chamber dimensions and wall thicknesses were measured in all patients. Utilizing these data, indices of left ventricular function were derived: shortening fraction, velocity of fiber shortening, peak diastolic fiber lengthening, end-systolic wall stress, radius thickness ratio, and ventricular mass.

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An adolescent female with occult cystic medial necrosis died following spontaneous aortic rupture. A large saccular aortic aneurysm that had ruptured into the pericardial space was demonstrated by two-dimensional echocardiography and confirmed at surgery. Echocardiographic screening of the patient's family members revealed a 13-year-old brother with unsuspected aortic root dilatation.

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A 44-year-old man was found unconscious beneath an elevated rapid transit right-of-way. On admission to the emergency room, the patient was comatose in metabolic acidosis with high anion and osmolal gaps. The serum methanol was 583 mg/dL.

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The following is a list of generalizations that arise from considering the present state of knowledge concerning the functions of invertebrate peptides. Some of these clearly also apply to vertebrates. Invertebrate peptides can be classified into structurally related groups.

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Amino acid sequences have been assigned to two cockroach neuropeptides (greater than Glu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, M I, and greater than Glu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, M II) by application of fast atom bombardment mass spectrometry, including high resolution and linked scan (metastable) studies. The peptides show considerable homology with two other invertebrate neuropeptides, adipokinetic hormone (AKH, from a locust) and red pigment concentrating hormone (RPCH, from a prawn), whose fast atom bombardment spectra were also studied. M I and M II are thus members of a family of structurally-related invertebrate neuropeptides.

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We report a fatal case of drug toxicity associated with torsade de pointes following an overdose of the tetracyclic antidepressant, maprotiline (Ludiomil). Tissue and plasma levels were obtained at autopsy and are noted. In addition, the cardiovascular effects, pharmacokinetics, and toxicity of maprotiline are reviewed and compared with that of tricyclic antidepressants.

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Qualitative phase analysis of radionuclide angiocardiograms has been applied in pediatric nuclear cardiology. The technique involves the static and dynamic display of phase images. Qualitative phase analysis is valuable in two major images: (a) delineating borders of adjacent cardiac chambers such as the AV valve planes and the borders of the right ventricular outflow tract, for accurate selection of regions of interest, and (b) identifying and evaluating patterns of asynchronous contraction.

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In the case presented here of a 2-month-old boy with symptoms of upper respiratory infection, the physical examination, chest X-ray film and electrocardiogram led us to suspect congestive heart failure caused by either a primary or infectious cardiomyopathy or by a structural left ventricular outflow tract obstruction. The echocardiographic findings were the first evidence to suggest the presence of an intracardiac tumor. A cardiac computerized axial tomography scan supported the findings.

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The neuropeptide proctolin acts as a neuromuscular co-transmitter in insect skeletal muscle. As a prelude to determining whether other peptides may function in a similar way, we are attempting to isolate and characterize the chemical nature of new myoactive neuropeptides in insects. We examined the corpus cardiacum, a major insect neurosecretory structure of the American cockroach (Periplaneta americana), using a skeletal muscle bioassay and high pressure liquid chromatography fractionation and identified two myoactive factors, MI and MII.

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