Prehospital consideration of sildenafil-nitrate interactions.

Objective: To determine whether paramedics and on-line physicians screen patients for use of sildenafil citrate (Viagra) prior to prehospital administration of nitrates.

Methods: A prospective, observational study was performed over a one-month period in three EMS systems. Consecutive radio communications between on-line physicians and paramedics concerning male patients with cardiac complaints were monitored.

Molecular modeling of the three-dimensional architecture of the RNA component of yeast RNase MRP.

RNase mitochondrial RNA processing (MRP) is a ribonucleoprotein endoribonuclease that is involved in RNA processing events in both the nucleus and the mitochondria. The MRP RNA is both structurally and evolutionarily related to RNase P, the ribonucleoprotein endoribonuclease that processes the 5'-end of tRNAs. Previous analysis of the RNase MRP RNA by phylogenetic analysis and chemical modification has revealed strikingly conserved secondary structural elements in all characterized RNase MRP RNAs.

Mutagenesis of SNM1, which encodes a protein component of the yeast RNase MRP, reveals a role for this ribonucleoprotein endoribonuclease in plasmid segregation.

RNase MRP is a ribonucleoprotein endoribonuclease that has been shown to have roles in both mitochondrial DNA replication and nuclear 5.8S rRNA processing. SNM1 encodes an essential 22.

Mice lacking cytosolic copper/zinc superoxide dismutase display a distinctive motor axonopathy.

Objective: To characterize the motor neuron dysfunction in two models by performing physiologic and morphometric studies.

Background: Mutations in the gene encoding cytosolic superoxide dismutase 1 (SOD1) account for 25% of familial ALS (FALS). Transgenes with these mutations produce a pattern of lower motor neuron degeneration similar to that seen in patients with FALS.

Fibroma of tendon sheath of the infrapatellar fat pad.

We report on a 13-year-old boy who was found to have a fibroma of the tendon sheath associated with the patellar tendon and within Hoffa's fat pad of the knee. This benign tumor has never been described in this location previously. The MRI characteristics are correlated with the histologic findings.

Who has screening mammography? Results from the 1994-1995 National Population Health Survey.

Objective: To determine the characteristics of Canadian women aged 35 to 49 who receive screening mammograms not recommended by the Canadian Task Force on the Periodic Health Examination.

Design: Secondary data analysis of the 1994-1995 National Population Health Survey.

Setting: Patients' homes.

Nicotine's effect on hypothalamic neurotransmitters and appetite regulation.

Background: Tobacco smoking reduces appetite and body weight. Cessation of smoking leads to hyperphagia and weight gain. Food intake is a function of meal number (MN) and meal size (MZ) (i.

A naturalistic study of risperidone maintenance treatment of outpatients with severe mental illness.

In a naturalistic study of the effectiveness of atypical antipsychotics for the long-term outpatient treatment of persons with severe and persistent mental illness, 19 patients began taking risperidone and were prospectively evaluated. Nine patients dropped out of risperidone treatment before three months; four of them later responded to clozapine. The ten patients who completed the study on risperidone were less severely ill at baseline.

Activin A and TGF-beta stimulate phosphorylation of focal adhesion proteins and cytoskeletal reorganization in rat aortic smooth muscle cells.

Activin A and Transforming Growth Factor-beta (TGF-beta) are members of a common family of cytokines that bind to and stimulate serine/threonine kinase receptors. Activin A and TGF-beta are important during embryonic development exerting both positive and negative effects on cell growth. In the adult organism, they function in processes such as tissue repair, cellular proliferation, and differentiation.

Antisense oligonucleotide-induced inhibition of adrenocorticotropic hormone release from cultured human corticotrophs.

Object: Available therapies for Cushing's disease are often inadequate or involve the risk of significant morbidity. Accordingly, the need arises for the development of novel treatments, especially for cases caused by corticotroph hyperplasia, a condition difficult to treat using standard therapies. In this study, the authors investigated the use of phosphorothioate antisense oligonucleotides as a potential treatment for Cushing's disease.

Reentry and fibrillation in the mouse heart. A challenge to the critical mass hypothesis.

The idea that fibrillation is only possible in hearts exceeding a critical size was introduced by W. Garrey >80 years ago and has since been generally accepted. In ventricular tissue, this critical size was originally estimated to be 400 mm(2).

ETS transcription factors regulate an enhancer activity in the third intron of TNF-alpha.

We describe an enhancer site in the third intron of tumor necrosis factor alpha (TNF-alpha). A reporter construct containing the 5'-flanking region of the mouse TNF-alpha gene displayed weak activity when transfected into RAW264.7 macrophage-like cells.

Bilateral ovarian stromal hyperplasia concealing a nonhilar, pure stromal-Leydig cell tumor. A case report.

Background: Of ovarian stromal tumors containing Leydig cells, nonhilar, pure stromal-Leydig cell tumor is rare.

Case: An obese, diabetic, borderline hypertensive 41-year-old woman with a five-year history of oligomenorrhea and amenorrhea presented with complaints of masculinization. Physical examination revealed hirsutism and an enlarged clitoris.

Cranial bone grafting in maxillofacial trauma and reconstruction.

Although manipulation of cranial bone has a long history, the use of cranial bone for reconstruction of craniomaxillofacial defects has only become popular in the last 15 years. Many refinements in harvesting and placement techniques have occurred over that time period. Cranial bone is valued for craniofacial skeletal reconstruction because of the proximity of the donor site to the recipient site, reasonable resistance to resorbtion, suitable geometry, and ability to be rigidly fixated.

Videomicroscopy provides accurate in vivo assessment of pulmonary microvascular reactivity in rabbits.

When defining the mechanism of hypoxic pulmonary vasoconstriction (HPV), investigators have employed ex vivo preparations because of the belief that accurate, quantitative assessment of pulmonary microvessels could not be obtained in vivo. We hypothesize that accurate, quantitative assessment of pulmonary microvascular reactivity can be performed using a simple, in vivo preparation. Our aim was to provide this quantitative assessment in a defined animal model, and to confirm that the chosen preparation could discriminate changes in microvascular reactivity as influenced by endogenous mediators.

Respiratory syncytical virus-induced chemokine expression in the lower airways: eosinophil recruitment and degranulation.

Characterization of chemokine expression patterns in virus-infected epithelial cells provides important clues to the pathophysiology of such infections. The aim of this study was to determine the chemokine response pattern of respiratory epithelium when infected with respiratory syncytial virus (RSV). Macrophage inflammatory protein-1-alpha (MIP-1-alpha), interleukin-8 (IL-8), and RANTES concentrations were measured from RSV-infected HEp-2, MRC-5, and WI-38 cell culture supernatants daily following infection.

Soluble tumor necrosis factor receptor prevents post-pump syndrome.

Post-pump syndrome is an acute lung injury following cardiopulmonary bypass (CPB) which is indistinguishable from the adult respiratory distress syndrome (ARDS). Tumor necrosis factor (TNF) is central to the inflammatory process and is capable of triggering the entire pathophysiologic response leading to ARDS. We hypothesized that treatment with a soluble TNF receptor-binding protein (TNFbp) would reduce the increase in serum TNF and prevent acute lung injury in our sequential insult model of ARDS following CPB.

Enteroviral meningoencephalitis as a complication of X-linked hyper IgM syndrome.

We describe 5 children from 2 families with mutations in the CD40 ligand (CD40L) gene leading to absent expression of CD40L on activated CD4 cells. All subjects presented with interstitial pneumonia with low serum IgG and normal serum IgM. One child had normal and one child had elevated serum IgA.

Secretagogues cause ubiquitination and down-regulation of inositol 1, 4,5-trisphosphate receptors in rat pancreatic acinar cells.

Background & Aims: The action of several exocrine pancreas secretagogues depends on the second messenger inositol 1,4, 5-trisphosphate (IP3), which, via endoplasmic reticulum-located IP3 receptors, mobilizes intracellular Ca2+ stores. Signaling pathways like this one are regulated at multiple loci. To determine whether IP3 receptors are one of these loci, we measured IP3 receptor concentration, distribution, and modification in secretagogue-stimulated rat pancreatic acinar cells.

Respiratory syncytial virus infection: immune response, immunopathogenesis, and treatment.

Respiratory syncytial virus (RSV) is the single most important cause of lower respiratory tract infection during infancy and early childhood. Once RSV infection is established, the host immune response includes the production of virus-neutralizing antibodies and T-cell-specific immunity. The humoral immune response normally results in the development of anti-RSV neutralizing-antibody titers, but these are often suboptimal during an infant's initial infection.

Assaults by patients on psychiatric residents: a survey and training recommendations.

Objective: A survey was conducted to determine the frequency and severity of assaults on psychiatric residents and the level of training they receive in the management of violent patients.

Methods: In early 1997 a survey was randomly distributed to 2,553 psychiatric residents, who represented half of all psychiatric residents in the United States. The survey asked about experiences of assaults and training received in management of violent patients.

The long-term effects of pregnancy and bromocriptine treatment on prolactinomas--the value of radiologic studies.

Objective: To evaluate the long-term effects of pregnancy and bromocriptine treatment on prolactin-secreting pituitary tumors in women undergoing infertility treatment for prolactinomas.

Methods: The records of 17 patients with prolactinomas were reviewed. Data regarding age, prepregnancy baseline and postpartum serum prolactin levels, and radiologic studies including CT or MRI were assessed.

Hyperparathyroidism and pregnancy.

Background: Hyperparathyroidism during pregnancy can carry significant morbidity to both mother and fetus. Surgery is the definitive treatment of choice although medical management is occasionally warranted. This report looks at 6 cases of hyperparathyroidism during pregnancy and reviews the morbidity and mortality of this entity.

Methamphetamine overdose: experience with six cases.

We describe experience with 6 cases of methamphetamine overdose. Because of its low cost, easy availability and longer duration of action compared to cocaine, methamphetamine has become the drug of choice in various communities. Marked change in mental status was observed in all of our patients.