Implementation of extreme ultraviolet spectroscopy on a sheared-flow-stabilized Z pinch.

A diagnostic for extreme ultraviolet spectroscopy was fielded on the sheared-flow-stabilized (SFS) fusion Z-pinch experiment (FuZE-Q) for the first time. The spectrometer collected time-gated plasma emission spectra in the 5-40 nm wavelength (30-250 eV) range for impurity identification, radiative power studies, and for plasma temperature and density measurements. The unique implementation of the diagnostic included fast (10 ns risetime) pulsed high voltage electronics and a multi-stage differential pumping system that allowed the vacuum-coupled spectrometer to collect three independently timed spectra per FuZE-Q shot while also protecting sensitive internal components. Analysis of line emission identifies oxygen (N-, C-, B-, Be-, Li-, and He-like O), peaking in intensity shortly after maximum current (>500 kA). This work provides a foundation for future high energy spectroscopy experiments on SFS Z-pinch devices.

Potential population growth and harmful effects on humans from bed bug populations exposed to different feeding regimes.

Effects of host availability and feeding period on bed bugs, Cimex lectularius (L.) (Hemiptera: Cimicidae), were measured. Population growth and the potential harmful effect of bed bug populations on human hosts were modelled. Bloodmeal sizes were affected by both feeding length and frequency, with >2-fold difference between insects fed daily or weekly. Blood consumption increased >2-fold between bed bugs fed occasionally and often, and 1.5-fold between occasional and daily feeding. Bed bugs fed more often than once a week, potentially every 2-4 days. Egg production was associated with nutrition, being strongly correlated with blood consumption in the previous week. Bed bug populations can grow under different feeding regimes and are hard to control with <80% mortality. Bed bugs can survive and grow even in locations with a limited blood supply, where bed bug persistence may be important for the continual spread of populations. Persistence in non-traditional locations and a potential association with human pathogens increase the health risks of bed bugs. Potential blood loss as a result of a bed bug can have serious consequences because uncontrolled populations can reach harmful levels in 3-8 months. The reproduction potential of bed bug populations suggests serious consequences to human health and the need for efficacious control measures.

Preputial urinary diversion to treat urine soaking during urination in a dog.

A young dog was presented with a history of adopting an unusual posture to urinate, resulting in urine soaking of the ventral abdomen and caudal forelimbs. The dog was initially treated surgically with cranial advancement of the prepuce, which did not resolve the problem. Further surgery was then successfully carried out to create a more caudal preputial orifice, which angled the penis ventrally when extruded, directing urine away from the body. At follow-up clinical examination, the dog was clinically normal.

Phosphorylcholine-based polymer coatings for stent drug delivery.

Phosphorylcholine-based polymers have been used commercially to improve the biocompatibility of coronary stents. In this study, one particular polymer is assessed for its suitability as a drug delivery vehicle. Membranes of the material are characterized in terms of water content and molecular weight cut-off, and the presence of hydrophilic and hydrophobic domains investigated by use of the hydrophobic probe pyrene. The in vitro loading and elution of a variety of drugs was assessed using stents coated with the polymer. The rate of a drug's release was shown not to be simply a function of its water solubility, but rather more closely related to the drug oil/water partition coefficient. This finding was explained in terms of the more hydrophobic drugs partitioning into, and interacting with, the hydrophobic domains of the polymer coating. The suitability of the coated stent as a drug delivery vehicle was assessed in vivo using a radiolabeled analog of one of the more rapidly eluting drugs, angiopeptin. Autoradiography showed that the drug was released locally to the wall of the stented artery, and could be detected up to 28 days after implantation.

Breast carcinoma detection in women age 35 years and younger: mammography and diagnosis by fine-needle aspiration cytology.

BACKGROUND: Delays in breast carcinoma diagnosis may occur in young women due to a low index of suspicion. Fine-needle aspiration (FNA) is an ideal method for evaluating breast lesions in younger women. Mammographic and FNA findings, including nuclear grade, were studied to determine both the utility of FNA and the presence of unique cytologic features in women age < or = 35 years with breast carcinoma. METHODS: The cytopathology files were searched from 1984 to 1996 for FNA in women age < or = 35 years with breast carcinoma. The cytologic, mammographic, and clinical findings were reviewed in the 68 FNAs identified. A nuclear grade was assigned to each FNA. RESULTS: Thirteen patients were age < 30 years and 55 were age 31-35 years (range, 22-35 years; average, 31 years). The clinical and mammographic findings were carcinoma in 45 patients (66%) and fibroadenoma/benign in 23 patients (34%). FNA diagnoses were malignant/suspicious (86%), atypical (12%), and negative (1.4%). In 23 patients with unsuspected carcinoma, the FNA diagnosed or suggested malignancy in 22 of 23 patients (96%). The cytologic findings on review were variable. Many FNAs were cellular, with enlarged nuclei and prominent nucleoli. The FNAs predominantly were nuclear Grade 2 (47%) and 3 (47%); only 4 tumors were nuclear Grade 1 (6%). CONCLUSIONS: By detecting breast carcinoma in 23 patients with unsuspected carcinoma, this study demonstrates how breast FNA in young women can help avoid delays in diagnosis. The cytologic findings are striking for an increased incidence of high grade tumors.

The cost-effectiveness of fine-needle aspiration cytology and 14-gauge core needle biopsy compared with open surgical biopsy in the diagnosis of breast carcinoma.

BACKGROUND: Judicious utilization of fine-needle aspiration cytology (FNAC) and 14-gauge core needle biopsy (CB) theoretically should result in greater accuracy in breast carcinoma diagnosis and fewer unnecessary open surgical biopsies (OSBs), thus lowering health care costs. METHODS: In 1995 in Rochester, New York, the ratio of open surgical breast biopsies per each verified breast carcinoma (OSB/Ca) in a freestanding breast clinic (EWBC) was compared with the OSB/Ca ratio of all physicians in the remainder of the city. The EWBC differs from all other diagnostic facilities in Rochester in that it routinely performs FNAC and CB. RESULTS: The EWBC recommended 462 OSBs resulting in 310 verified carcinomas, for a OSB/Ca ratio of 1.5. The physicians in the remainder of the city recommended 2036 OSBs resulting in 513 verified carcinomas, for a OSB/Ca ratio of 4.0. If the EWBC OSB/Ca ratio had been identical to the remainder of the city, the number of extra OSBs recommended by the clinic would have been 778, resulting in an additional cost of $1,712,082. When the added cost of the 2594 FNACs ($256,285) and 403 CBs ($252,278) performed by the clinic was subtracted from the $1,712,082, the freestanding breast clinic cost savings was $1,203,519. The lymph node metastasis rate of 19% for the breast carcinomas diagnosed in clinic patients was identical to that of the women with breast carcinoma in the remainder of the city. CONCLUSIONS: Utilization of FNAC and CB allows radiologists to lower their OSB/Ca ratio without sacrificing early detection. In this study, these less expensive procedures result in lowered medical costs for the health care system.

Considerations for toxicology studies of respiratory drug products.

The standard approaches for the preclinical development of chronically administered drugs also apply to most respiratory drugs. Modifications from the standard preclinical development plan, however, may be necessary if the drug is administered intranasally or by inhalation. Administration by these routes may result in airway toxicity and the intended patient population is often particularly susceptible. Current and former representatives of the Division of Pulmonary Drug Products (CDER, U.S. FDA) present this article to describe general principles of preclinical development for respiratory drug indications. The article addresses drugs intended for administration by the intranasal or inhalation routes. The article describes the types of studies recommended, considers the initial human dose, and discusses dose-escalation strategies in clinical trials. Other areas of special concern with intranasal or inhalation administration include immunotoxicity, reproductive toxicity, types of dosing apparatus, excipients and extractables, and formulation changes. The approaches described in this article are intended as general information and should be adapted to the scientific considerations and circumstances of a particular drug under development.

Phosphorylcholine coating of ePTFE grafts reduces neointimal hyperplasia in canine model.

This study attempts to prevent neointimal hyperplasia by coating the graft luminal surface with a derivative of phosphorylcholine (PC), thereby providing a biocompatible surface with the assumption of limiting pannus tissue ingrowth from the graft anastomoses. Bilateral carotid artery bypass grafts were placed in six dogs using expanded polytetrafluoroethylene (ePTFE). In each animal, one carotid arterial-arterial conduit was constructed using a graft having a PC coating over the entire luminal surface of the graft. On the contralateral side, uncoated graft served as a control. The processed specimens were analyzed for graft neointimal area and neointimal thickness. Cell proliferation was assessed by staining for bromodeoxyuridine (BrdU) incorporation. All grafts were patent except one control graft that was occluded at 4 weeks. There was a significant reduction in the anastomotic graft neointimal area between the treated and control groups (0.27 +/- 0.17 mm2 versus 0.53 +/- 0.13 mm2, respectively; p = 0.008). Furthermore, the BrdU labeling index in the graft neointimal tissues was significantly smaller (p < 0.001) in the treated group (2.64 +/- 0.77%) as compared with the control group (5.07 +/- 0.83%). These data demonstrate that PC coating of ePTFE significantly reduces graft neointimal hyperplasia and cell proliferation in a canine carotid artery bypass model. The application of PC within the ePTFE graft effectively blocks tissue ingrowth from the adjacent native vessel, thereby preserving the anastomosis luminal diameter.

Factors affecting activation and fertilization of human oocytes following intracytoplasmic injection.

Intracytoplasmic sperm injection (ICSI) has dramatically altered the treatment of severe male factor infertility, resulting in improved fertilization and pregnancy rates. The purpose of this study was to investigate oocyte activation and fertilization in aged human oocytes following ICSI. Non-viable spermatozoa were injected into 24 h old human oocytes in the presence and absence of calcium and were assessed for evidence of activation and fertilization 16-19 h after the injection procedure. Sham injections were also carried out to assess the effect of the injection procedure itself and the presence of calcium in the injection medium on oocyte activation. Non-viable spermatozoa injected in the presence of 1.78 mM calcium were capable of normally fertilizing aged human oocytes and the resulting zygotes underwent cleavage. None of the oocytes injected with non-viable spermatozoa in the absence of calcium were fertilized normally, although the rates of activation following all treatments were similar.

Evaluation of a simple method for measuring the cellular DNA content of mouse oocytes and embryos, human fibroblasts and parthenogenetically activated human oocytes using a computerised image analysis system (Seescan).

We report the use of a simple, reproducible, photocytometric method for measuring nuclear DNA content of DAPI-stained cells, using a computerised image analysis system: Seescan. As this technique is non-destructive and uses very short exposure to ultraviolet light, it can be used for either fixed or vital material. After correcting for any background cytoplasmic staining, the intensity of nuclear stain was measured by the Seescan and compared with that of control cells of known ploidy. Fixed material was found to stain more intensely than live material initially, but demonstrated a rapid loss of nuclear intensity over the first 90 min following removal from DAPI, after which the level plateaued. In contrast, live cells showed no change in nuclear intensity with time. The system was validated by measuring the DNA content of carefully timed mouse blastomeres, human fetal lung fibroblasts and parthenogenetically activated human oocytes. The results obtained were appropriate for the developmental stage or phenotypic appearance of each of the cell types measured.

The early development and DNA content of activated human oocytes and parthenogenetic human embryos.

A total of 297 human oocytes that had failed to fertilize during in-vitro fertilization (IVF) cycles were exposed to the calcium ionophore A23187 to induce parthenogenetic activation. Of these oocytes, 192 (65%) activated, the majority (63%) exhibiting a single pronucleus and extruding a second polar body. The appearance of two pronuclei (18%) was generally associated with a failure to extrude the second polar body. Oocytes obtained from patients who were > or = 35 years had a significantly reduced activation rate (53%). The timing of developmental events, such as extrusion of the second polar body, appearance and disappearance of pronuclei and the first two cleavage divisions, is broadly similar to that seen in fertilized oocytes. However, the developmental potential of human parthenogenetic embryos was reduced, as the majority of those allowed to continue in culture arrested between the 2-cell and 8-cell stages. Measurements of cellular DNA content using a computerized image analysis system showed that activated oocytes with one pronucleus had a DNA content compatible with a haploid number of chromosomes, while those with two pronuclei were diploid. The ability of parthenogenetically activated oocytes to replicate their DNA was also demonstrated.

Emergency medicine educational objectives for the undifferentiated physician.

The term undifferentiated physician is applied to those physicians who have not received or are not receiving formal postgraduate training in emergency medicine. Many community and university hospitals offer an "emergency medicine" experience to this group of physicians, but most do not follow a defined curriculum. This set of educational objectives was developed under the auspices of the Canadian Association of Emergency Physicians (CAEP). The objectives are based on an instructional design model known as a Systems Approach Model, which is an objective-based model. The objectives are intended for the undifferentiated physician whose practice will include emergency department (ED) work. The objectives are based on a 2-month rotation in the ED under the supervision of an attending physician who has either College of Family Physicians of Canada or Royal College of Physicians and Surgeons of Canada certification in emergency medicine. The purpose of these objectives is to provide guidelines for a uniform framework for the basic emergency medicine education of these undifferentiated physicians.

Regulatory considerations for oligonucleotide drugs: updated recommendations for pharmacology and toxicology studies.

This article describes pharmacology and toxicity studies for oligonucleotide drugs that are recommended for inclusion in the initial Investigational New Drug Application (IND), a first request to use an investigational drug in clinical trials. Recent observations of non-sequence-dependent cardiovascular toxicity and deaths in monkeys following intravenous infusions of phosphorothioates have raised a potential safety concern for oligonucleotide drugs. This concern should be considered by drug sponsors in designing pre-IND nonclinical development programs and Phase I clinical protocols. Pre-IND conduct of pharmacodynamic cardiovascular screening is highly recommended for defining safe clinical dosing regimens for phosphorothioate (and, possibly, other charged-backbone) oligomers. Additionally, drug sponsors are encouraged to (1) conduct research into-the mechanisms responsible for this dose-limiting toxicity, (2) institute liberal publication policies for research conducted under industrial sponsorship, and (3) communicate with reviewing divisions at FDA for updated guidance in this field when planning pre-IND safety studies. Recommendations for nonclinical studies during development of oligonucleotides will be modified as new information regarding the biological properties of oligonucleotides becomes available.

Regulatory aspects of modifications to innovator bronchodilator metered dose inhalers and development of generic substitutes.

Regulatory requirements for modifications to an approved innovator metered dose inhaler (pressurized MDI; USP nomenclature: inhalation aerosol) and for development of a new generic product are discussed. Although many of the requirements apply generally to MDI's, they are discussed with specific reference to albuterol. Changes to the container and closure system may impact on the dosimetry of the redesigned product, as well as upon toxicologic and chemistry, manufacturing and controls (CMC) concerns. Changes to the formulation, including the use of alternate propellants, may raise issues requiring both clinical and in vivo performance evaluation. In view of the level of interest of a number of firms in approval requirements for generic Albuterol Inhalation Aerosol products, the article discusses in considerable detail the CMC and bioequivalence requirements for a generic product. Similarities in the CMC requirements for innovator and generic products are evident. Three comparative in vivo bioequivalence tests, particle size distribution, spray pattern and plume geometry, and unit spray content, established by the Division of Bioequivalence are discussed. Similarities and differences in the in vivo requirements for innovator and generic products are evident. Differences are the result of U.S. statute, which requires safety and efficacy testing for a product approved under a new drug application (NDA), but documentation of bioequivalence for a product approved under an abbreviated new drug application (ANDA). The advantages and disadvantages of three pharmacodynamic study designs which have potential usefulness for documentation of in vivo bioequivalence are discussed.

Conversion of paroxysmal supraventricular tachycardia in a child with a slow verapamil infusion: case report and literature review.

The investigators present the case of a 12-month-old female with Down's syndrome and an endocardial cushion defect who presented acutely ill in paroxysmal supraventricular tachycardia (PSVT). Unsuccessful vagal maneuvers were followed by a slow intravenous infusion of verapamil, during which the rhythm converted. The discussion which follows highlights the many issues to be addressed in the acute management of pediatric PSVT including the varied presentations, underlying etiologies, differential diagnosis, electrocardiographic findings, electrophysiologic mechanisms, and prognosis. The literature review concludes with a discussion of the many different therapies available for pediatric PSVT including vagal maneuvers, cardioversion, overdrive pacing, and pharmacologic therapies. In particular, the relative merits of verapamil and adenosine are discussed.

Further studies of the role of transforming growth factor-beta in human B cell function.

This study was designed to address three specific questions in human B cells. First, to determine whether transforming growth factor-beta (TGF-beta)2 has similar biologic effects on B cell function as does TGF-beta 1. Second, to test the hypothesis that TGF-beta 1 is an autocrine growth and differentiation inhibitor. Finally, because multiple receptor species for TGF-beta have been identified on other cell types, to determine by chemical cross-linking and competitive binding studies the nature of the TGF-beta 1 R present on normal and transformed B cells. Exogenous TGF-beta 2 was found to be functionally similar to TGF-beta 1 in its inhibition of factor dependent normal B cell proliferation and Ig secretion. When an antibody, specific for the active form of TGF-beta 1, was added in conjunction with IL-2 to previously stimulated B cell cultures, there was a 14.4 +/- 4.2% increase in B cell proliferation, a 22 +/- 6% increase in IgG production, and a 33 +/- 8.6% increase in IgM production when compared to control cultures. Chemical cross-linking of 125I-TGF-beta 1 to normal B cell membranes identified two major cross-linked species of 65 and 90 kDa. A fivefold excess of unlabeled TGF-beta 1 competitively inhibited the detection of both of these bands while a 50-fold excess of unlabeled TGF-beta 2 did not inhibit the 90-kDa band and only partially inhibited (60%) of the 65-kDa band. Chemical cross-linking of 125I-TGF-beta 1 to transformed B cell membranes identified only a single band of 60 kDa. Scatchard plot analysis of 125I-TGF-beta 1 binding to normal B cells that was competitively inhibited with increasing concentrations of unlabeled TGF-beta 1 revealed both high and low affinity binding sites whereas analysis of 125I-TGF-beta 1 binding in the presence of increasing concentrations of unlabeled TGF-beta 2 revealed only low affinity sites. These findings demonstrate that TGF-beta 2 is as effective as TGF-beta 1 in inhibiting human B cell function, that small amounts of active TGF-beta 1 are present endogenously in in vitro cultures which partially inhibit B cell function, that two major TGF-beta 1 R cross-linked complexes of 65 and 90 kDa are present on normal B cells, and that transformation of B cells may be accompanied by changes in the TGF-beta 1 R.

Antagonistic effects of phorbol esters on lymphocyte activation. Evidence that protein kinase C provides an early signal associated with lytic function.

There is increasing evidence that protein kinase C plays a role in the transduction of an activation signal in lymphocytes. The bulk of this evidence is based on pharmacological experiments involving the tumor promoter phorbol myristate acetate (PMA) as a protein kinase C agonist. However, in cytotoxic T lymphocytes, PMA has been shown to both stimulate and inhibit lytic function. By examining the effects of a series of phorbol esters on protein kinase C activity in lymphocytes, we will demonstrate that these antagonistic effects of PMA on cytotoxic T lymphocyte function are related to multiple effects of PMA on protein kinase C activity.

Incorporation of 5,8,11,14-eicosatetraynoic acid (ETYA) into cell lipids: competition with arachidonic acid for esterification.

5,8,11,14-eicosatetraynoic acid (ETYA), a widely used inhibitor of cyclooxygenase and lipoxygenase, inhibited the incorporation of 14C-arachidonic acid into cell lipids of the murine thymoma EL4 whereas oleic acid had no effect. Inhibition appeared to result from the ability of ETYA to compete with arachidonic acid for esterification enzymes and to be itself incorporated into cell lipids. The positional specificity for ETYA incorporation was similar to that of arachidonic acid. ETYA, but not oleic acid competed with arachidonate for activation by a selective arachidonoyl CoA synthetase in lymphocytes. This may explain in part the apparent specificity of effects seen on incorporation into whole cells. In addition ETYA, unlike other arachidonate analogs tested previously, caused significant inhibition of the nonselective acyl CoA synthetase in lymphocytes. These results are discussed with respect to the use of ETYA to examine the role of intrinsic arachidonic acid metabolism in cellular processes.

Inhibition of cytotoxic T lymphocyte-mediated lysis by ETYA: effect independent of arachidonic acid metabolism.

Cytotoxic T lymphocyte (CTL)-mediated lysis of target cells was inhibited by 5,8,11,14-eicosatetraynoic acid (ETYA) and other inhibitors of the lipoxygenase pathway at concentrations that inhibited arachidonic acid metabolism in mixed lymphocyte cultures. Inhibition was reversible and selective for the "lethal hit" stage in the CTL-target interaction. Studies to define CTL-specific arachidonic acid metabolites demonstrated that cloned CTL populations have little or no capacity to metabolize arachidonic acid. Therefore, inhibitor actions appear to be independent of the effects on CTL arachidonic acid metabolism. Alternative explanations for inhibitory effects are discussed.

Characterization of an arachidonic acid-selective acyl-CoA synthetase from murine T lymphocytes.

Evidence is presented that the murine thymoma EL4 and cytotoxic T lymphocyte clones possess two distinct long-chain fatty acyl-CoA synthetase activities. One enzyme shows activity toward a broad spectrum of fatty acid substrates, similar to the long-chain fatty acyl-CoA synthetase from rat liver. The other enzyme is selective for arachidonic acid and related fatty acids. Fatty acid competition studies using EL4 microsomes demonstrate that [14C]palmitoyl-CoA synthesis (Km = 13 +/- 1 microM, Vmax = 7 +/- 1 nmol/mg per min) is inhibited by unlabeled palmitate, oleate, linoleate or linolenate (Ki = 15-25 microM) and weakly by arachidonate (Ki greater than 100 microM). Similar inhibition is observed for the activation of [14C]oleate (Km = 31 +/- 3 microM, Vmax = 6 +/- 2 nmol/mg per min). On the other hand, [14C]arachidonyl-CoA synthetase (Km = 15 +/- 3 microM, Vmax = 13 +/- 2 nmol/mg per min) is inhibited by unlabeled arachidonic acid (Ki = 20 microM) but not by unlabeled palmitate, oleate, linoleate and linolenate. The description of arachidonoyl-CoA synthetase in cytotoxic T lymphocyte clones represents the first example of a cell with little or no capacity to synthesize arachidonic acid metabolites, yet which possesses a selective esterification mechanism for the fatty acid. Studies on the specificity of the arachidonic acid-selective acyl-CoA synthetase utilized arachidonic acid metabolites and structurally related fatty acids and yielded two points of interest: (1) metabolism of arachidonic acid to monohydroxy fatty acids (HETEs) resulted in compounds with significantly decreased ability to be activated by the arachidonate-selective acyl-CoA synthetase; (2) arachidonate was a much better substrate than was 5,8,11-eicosatrienoic acid (Km = 41 microM), the fatty acid which accumulates during essential fatty acid deficiency. The possible role of an arachidonic acid-selective acyl-CoA synthetase in lymphocyte activation and as a homeostatic mechanism during essential fatty acid deficiency is discussed.