Torque-mixing magnetic resonance spectroscopy.

A universal, torque-mixing method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by magnetic induction, the transverse component of a precessing dipole moment can be measured in sensitive broadband spectroscopy, here using a resonant mechanical torque sensor. Unlike induction, the torque amplitude allows equilibrium magnetic properties to be monitored simultaneously with the spin dynamics. Comprehensive electron spin resonance spectra of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature reveal assisted switching between magnetization states and mode-dependent spin resonance interactions with nanoscale surface imperfections. The rich detail allows analysis of even complex three-dimensional spin textures. The flexibility of microelectromechanical and optomechanical devices combined with broad generality and capabilities of torque-mixing magnetic resonance spectroscopy offers great opportunities for development of integrated devices.

Quantitative magneto-mechanical detection and control of the Barkhausen effect.

Quantitative characterization of intrinsic and artificial defects in ferromagnetic structures is critical to future magnetic storage based on vortices or domain walls moving through nanostructured devices. Using torsional magnetometry, we observe finite size modifications to the Barkhausen effect in the limiting case of a single vortex core interacting with individual pointlike pinning sites in a magnetic thin film. The Barkhausen effect in this limit becomes a quantitative two-dimensional nanoscale probe of local energetics in the film. Tailoring the pinning potential using single-point focused ion beam implantation demonstrates control of the effect and points the way to integrated magneto-mechanical devices incorporating quantum pinning effects.

Angiotensin-converting enzyme activity by canine pulmonary microvascular and central pulmonary artery endothelial cells exposed to hypoxia.

To compare the amount of angiotensin-converting enzyme (ACE) activity in pulmonary artery endothelial cells from different sites and to examine the effect of severe hypoxia (less than 1% of O(2) in 5% CO(2) and 95% N(2)) on the ACE activity expressed by these cells, endothelial cells were harvested and cultured from canine main pulmonary artery by scraping the luminal surface of the artery and from canine pulmonary artery microvessels by infusing chilled buffer with microcarrier beads and 0.02% ethylenediamine tetraacetic acid (EDTA). ACE activity in cell lysates and culture medium was evaluated by fluorometric assay with hippuryl-L-histidyl-L-leucine as a substrate. ACE activity in cell lysates and postculture medium of pulmonary microvascular endothelial cells (PMVEC) was higher than in cell lysates and culture medium of central pulmonary artery endothelial cells (PAEC). However, hypoxia suppressed cellular ACE activity in both PAEC and PMVEC. The degree of suppression of ACE activity by hypoxia, which was determined as (ACE activity in normoxia - ACE activity in hypoxia)/ACE activity in normoxia x 100(%), was larger in PMVEC than in PAEC. The pulmonary microvasculature may be a greater source of ACE than central pulmonary artery, and the ACE activity of pulmonary microvascular endothelial cells seem to be sensitive to hypoxia, although the small diameter of the vessels improves conditions for interaction of blood-borne substance with endothelial enzymes.

Periosteal chondroma of the cuboid presenting in a 7-year-old-boy.

This case report discusses the finding of a periosteal (juxtacortical) chondroma of the cuboid in a 7-year-old male. While this lesion is well recognized in the tubular bones of adults, this case is unusual due to the child's age, the site of the lesion (cuboid), and the difficulty in establishing the diagnosis due to the cellular atypia. The child was treated with marginal resection and curettage with no evidence of local recurrence on follow-up. A review of the literature is also included in the discussion.

Isolation of endothelial cells and their progenitor cells from human peripheral blood.

PURPOSE: We have developed techniques to isolate endothelial cell (EC) progenitors from human peripheral and umbilical cord blood. METHODS: Human adult peripheral and umbilical cord blood monocytes were isolated by centrifugation, and progenitor cells were separated with the use of magnetic polystyrene beads that were coated with a monoclonal antibody specific for the CD34 cell-membrane antigen. Cells were propagated in selective media, and developing cultures were immunostained for CD31, CD34, factor VIII, and vascular endothelial growth factor cell receptors. ECs that developed were transfected with a gene for prourokinase and used to line ePTFE grafts, which were evaluated in vitro in a pulsatile flow system. RESULTS: Umbilical cord monocyte cultures demonstrated colonies that resembled ECs at approximately 2 weeks, with growth being best supported by EC growth media plus 20% calf serum with iron. Immunostaining of colonies was positive for CD31 and factor VIII. After 18 days in culture, CD34(+) cells from adult peripheral blood were noted, which had the typical cobblestone appearance of ECs and immunostained positively for CD31 and factor VIII-related antigens. Cultures of umbilical cord-derived cells and adult peripheral blood-derived cells developed complex line formations within 1 week in culture that stained positively for vascular endothelial growth factor receptor-2. Urokinase-transfected ECs were shown to overexpress urokinase. Prosthetic grafts lined with transfected cells showed 87.33% +/- 4.97% cell adherence after 2 hours in a pulsatile flow system at clinically relevant shear stress. CONCLUSION: We conclude that endothelial progenitor cells can be isolated from human adult peripheral and umbilical cord blood and developed into EC cultures as a source of cells for vascular graft seeding and gene therapy.

Squamous cell carcinoma arising in a ciliated hepatic foregut cyst.

Ciliated hepatic foregut cysts are rare congenital lesions derived from the embryologic foregut. They are considered benign, and a review of 64 published cases revealed no instances of malignant transformation. We report a case of squamous cell carcinoma arising in a ciliated hepatic foregut cyst in a 51-year-old man. The tumor was found during a routine cholecystectomy and involved the adjacent mesentery and duodenal wall. There was histologic evidence of perineural and perivascular involvement. Despite an en bloc resection of the tumor and contiguous areas of gross involvement, the patient died 2 months later. Although aspiration of cyst contents is an accepted treatment for asymptomatic lesions, this case suggests that most ciliated hepatic foregut cysts should be excised, especially when radiologic studies yield equivocal results.

Ciliated hepatic foregut cyst: a study of six cases and review of the literature.

Ciliated hepatic foregut cyst (CHFC) is a rare, benign, solitary cyst consisting of ciliated pseudostratified columnar epithelium, subepithelial connective tissue, a smooth muscle layer, and an outer fibrous capsule. We studied six previously unreported cases of CHFC and 50 cases from the literature. The literature search revealed that Friedreich first described the lesion in 1857 and hypothesized its congenital origin. The cyst generally is found incidentally on radiologic imaging or during surgical exploration, although one case presented with portal vein compression. It occurs more frequently in men and is found most commonly in the medial segment of the left hepatic lobe, unlike most other solitary cysts that show a female predominance and greater occurrence in the right hepatic lobe. Two of the 56 cases were multilocular. There has been an increase in the number of reports of CHFC during the past 15 years. This may reflect the increased availability and use of various radiologic imaging modalities. A large number of cases have been reported in the Japanese population, but the significance of this is unclear. CHFC should be considered in the differential diagnosis of other solitary liver cysts, including simple cysts, hepatobiliary cystadenomas, and parasitic cysts.

Spontaneous partial expectoration of an endobronchial carcinoid.

Typical pulmonary carcinoid tumors often present as proximal endobronchial masses discovered during the evaluation of cough and/or hemoptysis. We present a case of a carcinoid tumor that presented with spontaneous partial expectoration. A review of the literature revealed 16 cases of expectoration of fragments from various primary and metastatic tumors. Our case appears to be the first report of the expectoration of a carcinoid tumor.

Mixed-type autoimmune hemolytic anemia following fludarabine treatment in a patient with chronic lymphocytic leukemia/small cell lymphoma.

BACKGROUND AND OBJECTIVES: Mixed-type autoimmune hemolytic anemia (AIHA) is a rare complication of chronic lymphocytic leukemia (CLL). We report a patient with small lymphocytic lymphoma (phenotypic CLL) who developed symptomatic anemia 3 weeks after her fifth cycle of fludarabine, a T cell immunosuppressant. MATERIALS AND METHODS: An antibody screen and panel, direct antiglobulin test, rapid acid eluate, rabbit erythrocyte stroma (RESt) adsorption, and autoadsorption were performed. RESULTS: Warm and cold autoantibodies were detected. prompt treatment with corticosteroids and minimal blood transfusions led to marked improvement. CONCLUSION: Normally, T cells suppress polyclonal lymphocytes that produce autoantibodies. Suppression of T cells in this patient, in addition to the underlying disease process, may explain this mixed-type AIHA, the first reported case to occur following fludarabine treatment.

Occupant generated carbon dioxide as a measure of dilution ventilation efficiency.

The time rate of decay of occupant generated carbon dioxide after workers have left a work area can be used in indoor air quality screening. Tests in a dilution chamber proved the goodness-of-fit of a limited exponential decay model. Correlation coefficients for the log-linear plots of the chamber tests approached unity as did the ratios of actual airflow to calculated flow. The model was used to estimate the number of air changes per unit time at the point of sample collection. Multiplying the number of air changes per minute by the room volume gave the effective ventilation rate. Dividing the actual quantity of air entering the space by the effective quantity provided a measure of ventilation effectiveness, i.e., a measure of mixing. The number of room air changes measured by carbon dioxide decay was positively correlated with the evaluator's qualitative assessment of the ventilation effectiveness in several offices and laboratories.

The safety of manipulative treatment: review of the literature from 1925 to 1993.

Many osteopathic medical students and physicians have an inherent fear of injuring patients when they perform osteopathic manipulative treatment (OMT). Based on the estimated several hundred million treatments performed each year in the United States as well as a review of the literature over the past six decades, only 185 reports of injury were found. However, besides good training in these techniques, the key to the safety of OMT is the taking of a thorough patient history and performing a thorough physical examination before the application of any manipulative procedure.

Determination of normal human fetal immunoglobulin M levels.

Immunoglobulin M (IgM) levels were measured in 198 cord blood samples from 192 apparently normal pregnancies from 24 weeks of gestation to term. Simple linear regression analysis yielded a standard curve for IgM development during pregnancy showing a 0.5 mg/dl increase in IgM per week of gestation. This curve allows the comparison of fetal IgM levels from pregnancies considered to be at risk for intrauterine infection.

Atrial myocytes cultured from explanted human adult myocardium demonstrate DNA replication.

The current theory of myocardial development holds that after a limited number of divisions, the myocardiocytes of the developing heart are irreversibly withdrawn from the generation cycle. It is, therefore, considered impossible to grow adult human myocardiocytes in culture, making it necessary for studies of cardiac muscle in culture to be carried out using animal or fetal human models. Recently, we developed a method for isolating, culturing, and characterizing myocardiocytes derived from explanted adult human atrial myocardium. A highly pure fraction (93%) of one of four morphologically discrete cell populations was separated using selective attachment techniques. These cells possessed features consistent with those seen in animal and fetal myocardiocytes. Using immunoperoxidase stains, these cells stained positive for actin, myoglobin, and atrial natriuretic peptide, proving the cells are myocardial muscle cells. Electron microscopy showed numerous bundles of myofibrils with interspersed dense Z-bodies and pleomorphic mitochondria. Bromo-deoxyuridine incorporation confirmed that the cells were replicating their DNA. Thus, cell morphology, immunoperoxidase stains, electron microscopy, and cell proliferation testing showed these cells to be myocardiocytes undergoing DNA replication and mitosis. We must now reconsider our current thinking about myocardial development and investigate what factors contribute to the inhibition of myocardial cell proliferation after injury in vivo.

Effect of papaverine on endothelial cell harvest from canine external jugular veins.

Endothelial cell seeding procedures have been developed to line prosthetic bypass grafts used in peripheral vascular disease; however, because of current inefficient cell harvest techniques a high ratio of vein-to-graft area is necessary. This study was done to determine if the use of papaverine, a smooth muscle cell relaxant, would affect the number or viability of endothelial cells harvested from canine external jugular veins. Using a 0.12 mg/ml solution of papaverine in tissue culture medium to bathe the veins during dissection and excision, the viable cell yield was 2.20 +/- 1.16 (cells x 10(4)/cm2). A control group of veins using standard dissection technique gave a yield of 0.97 +/- 0.40 (p = 0.025). A second group of veins dissected while bathed in tissue culture medium alone gave a yield of 1.82 +/- 0.75, compared to a yield of 2.73 +/- 0.45 for papaverine harvested veins (p = 0.009). Percent cell viability was not significantly different for any of the groups: 73, 70, and 76% for papaverine, control and media only veins, respectively. The papaverine-harvested cells and those harvested with medium alone grew to 95% confluence in tissue culture in 9.8 +/- 1.1 and 9.9 +/- 0.9 days, respectively. Compared to conventional surgical techniques, use of papaverine more than doubled the endothelial cell yield from excised vein segments without adversely affecting viability or rate of growth in cell culture.

Transcervical chorionic villus sampling and amniocentesis: a comparison of reliability, culture findings, and fetal outcome.

We evaluated the reliability, culture findings, and fetal outcome after transcervical chorionic villus sampling or amniocentesis in a group of 860 patients. All procedures were performed for the indication of advanced maternal age with consistent procedure and laboratory techniques. Successful procedures were completed in 97.7% (420/430) of patients in the chorionic villus sampling group, compared with 99.5% (428/430) in the amniocentesis group (p less than 0.01). Success was more frequent with only one attempt in the amniocentesis group (427/428) versus 354 of 420 in the chorionic villus sampling group (p less than 0.001). Culture failure was more common after chorionic villus sampling (p less than 0.001). Pregnancy loss rates through 28 weeks' gestation and the entire gestation were not significantly different. The prevalence of preterm delivery did not vary between groups, but birth weights of infants in the chorionic villus sampling group were significantly greater. In summary, the present investigation supports previous findings that chorionic villus sampling is a safe alternative to amniocentesis and is not associated with long-term pregnancy complications.

Bilateral renal agenesis and Mullerian anomalies in a 47,XXX fetus.

Congenital absence of the kidneys (bilateral renal agenesis, BRA) is a genetically heterogeneous condition, and all modes of inheritance have been suggested as causes. The finding of a 47,XXX chromosome constitution in a fetus with BRA and developmental arrest of the mesonephric and paramesonephric systems raises the possibility that X chromosome trisomy also may cause the urogenital adysplasia sequence.

A comparative curricular review project.

This article describes a curriculum review project at the Texas College of Osteopathic Medicine. The authors used the Core Curriculum in Osteopathic Education as a standard of comparison of the comprehensiveness of the college's instruction in osteopathic philosophy, principles, and practices and to clarify any differences between the Core Curriculum document and the college curriculum. The process involved a course-by-course search by student physicians and was reviewed by course faculty. Results revealed that the college's coverage was very similar to that proffered by the Core Curriculum. However, there were areas of instructional redundancy, questions of sequencing, and a few topics not addressed within the college curriculum. Thereafter, the faculty consolidated several courses, which produced a net savings of weekly contact hours and allowed further curricular change. Particular attention was given to the manner in which the other courses were scheduled, and, in turn, the consistency and stability of the entire first year was improved significantly.

Methods for the detection of a specific Mycobacterium leprae antigen in the urine of leprosy patients.

Two methods for detecting the phenolic glycolipid, PGL-1, a Mycobacterium leprae-specific molecule, in the urine of leprosy patients are described. Both methods rely on the 100-fold preconcentration of the urine, which can be accomplished by a single-step ultrafiltration procedure. The equivalent of approximately 2.5 micrograms of PGL-1/ml was detected in the urine of LL patients with an inhibition ELISA. The second method, a direct dot-blot assay on nitrocellulose paper, was much simpler and more sensitive. As little as 3 ng of antigen was detected by the dot-blot technique. PGL-1 was detected in the urine of LL patients.