Early gas stripping as the origin of the darkest galaxies in the Universe.

The known galaxies most dominated by dark matter (Draco, Ursa Minor and Andromeda IX) are satellites of the Milky Way and the Andromeda galaxies. They are members of a class of faint galaxies, devoid of gas, known as dwarf spheroidals, and have by far the highest ratio of dark to luminous matter. None of the models proposed to unravel their origin can simultaneously explain their exceptional dark matter content and their proximity to a much larger galaxy. Here we report simulations showing that the progenitors of these galaxies were probably gas-dominated dwarf galaxies that became satellites of a larger galaxy earlier than the other dwarf spheroidals. We find that a combination of tidal shocks and ram pressure swept away the entire gas content of such progenitors about ten billion years ago because heating by the cosmic ultraviolet background kept the gas loosely bound: a tiny stellar component embedded in a relatively massive dark halo survived until today. All luminous galaxies should be surrounded by a few extremely dark-matter-dominated dwarf spheroidal satellites, and these should have the shortest orbital periods among dwarf spheroidals because they were accreted early.

TheNational Commission on Nurse Anesthesia Education 10 years later--Part 1: The commission years (1989-1994).

The significant decrease in the number of anesthesia providers during the late 1980s prompted American Association of Nurse Anesthetists (AANA) leaders to establish the National Commission on Nurse Anesthesia Education (NCNAE). The NCNAE was charged with scrutinizing all aspects of nurse anesthesia educational programs and developing strategies to reverse the critical shortage of nurse anesthetists. The tactics outlined by the commissioners were implemented, and they resulted in an increase of annual nurse anesthesia program graduates. Although there has been continued realization of NCNAE strategies, 10 years later the critical shortage of CRNAs has resurfaced. This 2-part article describes the commission years, the years that followed, and the current status of Certified Registered Nurse Anesthetist (CRNA) manpower.

The National Commission on Nurse Anesthesia Education 10 years later--Part 2: Years following the commission (1994 to present).

In 1989, the National Commission on Nurse Anesthesia Education was implemented to reverse a severe shortage of CRNAs. The Commission, charged with scrutinizing all aspects of nurse anesthesia educational programs, developed 8 goals with corresponding strategies that were used by the Commission Implementation Task Force to actualize its charge. These goals and strategies contributed to an increase of annual graduates from nurse anesthesia programs and the development of 10 new programs. These activities were documented in Part 1 of this article, which appeared in the October 2001 AANA Journal. Following completion of the 3-year project, the Council on Accreditation of Nurse Anesthesia Educational Programs (COA) and the AANA Education Committee began carrying out the final recommendations made by the Commission. Part 2 addresses the accomplishments of the Education Committee and COA in implementing the recommendations of the Commission, discusses current status of educational programs and CRNA manpower, and identifies roles for both educators and practitioners in protecting the future of the profession.

Prospective analysis of complications 30 days after outpatient colonoscopy.

BACKGROUND: Our objective was to (1) determine whether more complications are reported by patients 30 days after outpatient colonoscopy than are discussed at our monthly morbidity and mortality conferences, (2) identify complications resulting in visits to the emergency department or physician's office or leading to hospitalization, and (3) assess which factors put patients at highest risk. A secondary goal was to determine the rate of work lost after outpatient colonoscopy. METHODS: Trained interviewers performed standardized telephone interviews of consecutive outpatients undergoing colonoscopy at Georgetown University Hospital over a 1-year period. RESULTS: One thousand one hundred ninety-six patients were contacted 30 days after outpatient colonoscopy and participated in our study. Twenty patients had complications that required a visit to an emergency department or physician. Ninety percent of these cases (18) were detected at 30 days, but 15% (3) were discussed at morbidity and mortality conferences. All seven complications that necessitated hospitalization were identified at 30 days, but only two were discussed at our morbidity and mortality conference. The most common complications reported by patients were abdominal discomfort (5.4%) and rectal bleeding (2.1%). CONCLUSION: More complications are detected by means of contacting patients 30 days after outpatient colonoscopy than are discussed at our morbidity and mortality conferences.

Dopamine agonist-mediated rotation in rats with unilateral nigrostriatal lesions is not dependent on net inhibitions of rate in basal ganglia output nuclei.

Current models of basal ganglia function predict that dopamine agonist-induced motor activation is mediated by decreases in basal ganglia output. This study examines the relationship between dopamine agonist effects on firing rate in basal ganglia output nuclei and rotational behavior in rats with nigrostriatal lesions. Extracellular single-unit activity ipsilateral to the lesion was recorded in awake, locally-anesthetized rats. Separate rats were used for behavioral experiments. Low i.v. doses of D1 agonists (SKF 38393, SKF 81297, SKF 82958) were effective in producing rotation, yet did not change average firing rate in the substantia nigra pars reticulata or entopeduncular nucleus. At these doses, firing rate effects differed from neuron to neuron, and included increases, decreases, and no change. Higher i.v. doses of D1 agonists were effective in causing both rotation and a net decrease in rate of substantia nigra pars reticulata neurons. A low s.c. dose of the D1/D2 agonist apomorphine (0.05 mg/kg) produced both rotation and a robust average decrease in firing rate in the substantia nigra pars reticulata, yet the onset of the net firing rate decrease (at 13-16 min) was greatly delayed compared to the onset of rotation (at 3 min). Immunostaining for the immediate-early gene Fos indicated that a low i.v. dose of SKF 38393 (that produced rotation but not a net decrease in firing rate in basal ganglia output nuclei) induced Fos-like immunoreactivity in the striatum and subthalamic nucleus, suggesting an activation of both inhibitory and excitatory afferents to the substantia nigra and entopeduncular nucleus. In addition, D1 agonist-induced Fos expression in the striatum and subthalamic nucleus was equivalent in freely-moving and awake, locally-anesthetized rats. The results show that decreases in firing rate in basal ganglia output nuclei are not necessary for dopamine agonist-induced motor activation. Motor-activating actions of dopamine agonists may be mediated by firing rate decreases in a small subpopulation of output nucleus neurons, or may be mediated by other features of firing activity besides rate in these nuclei such as oscillatory firing pattern or interneuronal firing synchrony. Also, the results suggest that dopamine receptors in both the striatum and at extrastriatal sites (especially the subthalamic nucleus) are likely to be involved in dopamine agonist influences on firing rates in the substantia nigra pars reticulata and entopeduncular nucleus.

Prospective analysis of complications 30 days after outpatient upper endoscopy.

OBJECTIVE: The aim of this study was to compare complication rates reported by patients 30 days after outpatient upper endoscopy with those discussed at our monthly morbidity and mortality conference. We also intended to establish which complications were reported most frequently 30 days after upper endoscopy, and which patients or procedures involved the highest risk. METHODS: Trained interviewers performed standardized telephone interviews on consecutive outpatients undergoing upper endoscopy over a 1-yr period. Patients were queried regarding potential events related to their upper endoscopy in the 30 days subsequent, including symptoms, emergency room (ER) and/or physician visits, and hospitalizations. The indications, findings, and therapies were reviewed from endoscopic reports. RESULTS: A total of 473 patients were contacted 30 days after outpatient upper endoscopy and agreed to participate in our study. The most common complications reported by patients at 30 days were sore throat (9.5%) and abdominal discomfort (5.3%). Twelve patients (2.5%) required an ER/physician visit and five patients (1.1%) required hospitalization. The minority of both ER/physician visits (16.7%) and hospitalizations (40%) were discussed at our monthly morbidity and mortality conferences. CONCLUSIONS: More complications were reported by patients 30 days after outpatient upper endoscopy than were discussed at our monthly morbidity and mortality conferences. The most frequent complications reported by patients were sore throat and abdominal pain. The minority of ER/physician visits and hospitalizations were discussed at our morbidity and mortality conferences.

Successful meropenem therapy of a brain abscess and meningitis arising from acute purulent otomastoiditis: case report.

We describe a case of a 25-year-old female with an acute left otomastoiditis, accompanied by a left temporal extradural abscess with moderate perifocal edema and meningitis. Intravenous meropenem (2 g 8-hourly) and intravenous methylprednisolone (40 mg once daily) were commenced empirically. Teicoplanin (400 mg once daily intravenously) was added after 5 days when culture results were available. Teicoplanin was discontinued on day 25 but meropenem and methylprednisolone were continued for a further 15 days, after which the abscess completely resolved without sequelae. No treatment-induced adverse effects or seizures were observed. Thus, in selected patients, antibacterials (in conjunction with a corticosteroid) may be successfully used without surgery to treat brain abscesses and in such circumstances meropenem is a useful option for empiric therapy.

The response of subthalamic nucleus neurons to dopamine receptor stimulation in a rodent model of Parkinson's disease.

Overactivity in the subthalamic nucleus (STN) is believed to contribute to the pathophysiology of Parkinson's disease. It is hypothesized that dopamine receptor agonists reduce neuronal output from the STN. The present study tests this hypothesis by using in vivo extracellular single unit recording techniques to measure neuronal activity in the STN of rats with 6-hydroxydopamine-induced lesions of the nigrostriatal pathway (a model of Parkinson's disease). As predicted, firing rates of STN neurons in lesioned rats were tonically elevated under basal conditions and were decreased by the nonselective dopamine receptor agonists apomorphine and L-3, 4-dihydroxyphenylalanine (L-DOPA). STN firing rates were also decreased by the D2 receptor agonist quinpirole when administered after the D1 receptor agonist (+/-)- 1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol (SKF 38393). Results of the present study challenge the prediction that dopaminergic agonists reduce STN activity predominantly through actions at striatal dopamine D2 receptors. Firing rates of STN neurons were not altered by selective stimulation of D2 receptors and were increased by selective stimulation of D1 receptors. Moreover, there was a striking difference between the responses of the STN to D1/D2 receptor stimulation in the lesioned and intact rat; apomorphine inhibited STN firing in the lesioned rat and increased STN firing in the intact rat. These findings support the premise that therapeutic efficacy in the treatment of Parkinson's disease is associated with a decrease in the activity of the STN, but challenge assumptions about the roles of D1 and D2 receptors in the regulation of neuronal activity of the STN in both the intact and dopamine-depleted states.

[Clarithromycin in pediatric age. Personal experience]. / La claritromicina nell'età pediatrica. Esperienza personale.

The authors report their experience on the use of oral suspension of Clarithromycin in respiratory infections in the pediatric age. Thirty-three patients affected by various infectious pathologies of the respiratory tract, treated with oral Clarithromycin at the dosage of 15 mg/kg/day, were studied. The therapeutic outcome was very encouraging, the drug well tolerated and without side effects.

Nurse anesthesiology faculty: what is your commitment?

Faculty workload determination formulas are a means by which program directors can justify their time and that of other faculty. This article is written to assist faculty in this necessary yet time-consuming endeavor. A table of calculations (time/activity ratio) for determination of committed hours, examples of actual workload determination, and a worksheet are provided.

Human amoebiasis: the interaction of lymphocyte surface-bound immune complexes and PMNs impairs T cell proliferative responses to E. histolytica mitogen.

In some of the sera from patients with amoebiasis circulating immune complexes are present which are thought to interact with lymphoid cells, enabling them to elicit a burst of oxygen consumption in PMNs. The intensity of chemiluminescence is related to the presence of C3+ and Fc IgG+ cells in the lymphoid cell suspensions employed. The generation and release of highly reactive oxygen derivatives from PMNs impair T lymphocyte proliferative responses to the E. histolytica mitogen. The Authors suggest that one of the mechanisms by which circulating immune complexes present in the sera of patients with amoebiasis may interfere with T cell-mediated immune responses, is through their binding to the surface of the C3+, Fc IgG+ cells with subsequent stimulation of the PMN oxidative metabolism.

Methisoprinol and corticosteroids: immunopharmacokinetic assessment.

Methisoprinol is an antiviral drug with immunopotentiating properties. The aim of this study was to assess the immunopharmacokinetic profile of the drug alone or administered in conjunction with corticosteroids. The plasma of patients who had been given a single dose of methisoprinol, prednisolone or both was collected before the infusion and at different time intervals thereafter. The plasma samples were tested for immunosuppressive or immunopotentiating activity in a mixed lymphocyte culture (MLC). The test was modified to increase sensitivity and decrease variability. The administration of methisoprinol resulted in increased responses up to three hours after the infusion. The simultaneous administration of both drugs resulted in an even more marked inhibition of MLCs as compared with corticosteroids alone.