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Biomedical subjects

M Ackerman

Publications and source records attributed to M Ackerman.

At least 19 recordsLinked to original sources

Ngi and Internet2: accelerating the creation of tomorrow's internet.

Internet2 is a consortium of leading U.S. universities working in partnership with industry and the U.S. government's Next Generation Internet (NGI) initiative to develop a faster, more reliable Internet for research and education including enhanced, high-performance networking services and the advanced applications that are enabled by those services [1]. By facilitating and coordinating the development, deployment, operation, and technology transfer of advanced, network-based applications and network services, Internet2 and NGI are working together to fundamentally change the way scientists, engineers, clinicians, and others work together. [http://www.internet2.edu] The NGI Program has three tracks: research, network testbeds, and applications. The aim of the research track is to promote experimentation with the next generation of network technologies. The network testbed track aims to develop next generation network testbeds to connect universities and federal research institutions at speeds that are sufficient to demonstrate new technologies and support future research. The aim of the applications track is to demonstrate new applications, enabled by the NGI networks, to meet important national goals and missions [2]. [http://www.ngi.gov/] The Internet2/NGI backbone networks, Abilene and vBNS (very high performance Backbone Network Service), provide the basis of collaboration and development for a new breed of advanced medical applications. Academic medical centers leverage the resources available throughout the Internet2 high-performance networking community for high-capacity broadband and selectable quality of service to make effective use of national repositories. The Internet2 Health Sciences Initiative enables a new generation of emerging medical applications whose architecture and development have been restricted by or are beyond the constraints of traditional Internet environments. These initiatives facilitate a variety of activities to foster the development and deployment of emerging applications that meet the requirements of clinical practice, medical and related biological research, education, and medical awareness throughout the public sector. Medical applications that work with high performance networks and supercomputing capabilities offer exciting new solutions for the medical industry. Internet2 and NGI,strive to combine the expertise of their constituents to establish a distributed knowledge system for achieving innovation in research, teaching, learning, and clinical care.

Internet↗

A kinase/phosphatase system involving the protooncogene Lck is necessary for inducible modulation of Sob 1 during T cell activation.

The phosphotyrosine containing protein Sob 1 regulates inducibility of a DNA binding complex (Band A) at the SRE of c-fos during T cell activation. In the present study, Sob 1 was regulated by activation of T cells through the T cell antigen receptor. Inhibition of protein tyrosine kinases (PTK) inactivated Sob 1 function and allowed the Band A DNA-protein complex to form. Inhibition of protein tyrosine phosphatases (PTP) caused constitutive activation of Sob 1 function and prevented induction of Band A at the SRE. Thus, Sob 1 is regulated by a constitutive PTP/PTK system. J.CaM 1 cells that lack a functional form of the PTK Lck are unable to induce Band A through the T cell antigen receptor. J.CaM 1 cells reconstituted with Lck seem to induce Band A normally. Thus, functional Lck is required for regulation of Sob 1.

Base Sequence↗

Importance of learned resourcefulness to weight loss and early success during maintenance: preliminary evidence.

The present study examined the importance of learned resourcefulness skills as measured by Rosenbaum's Self-Control Schedule (SCS) (Behav Ther 1980; 11: 109-121) to weight loss following a self-control program. Twenty-two women signed up for the 5-week self-control program. Participants' weight was recorded at the first and final session of the program, and at a 4-week follow-up. Results indicated that low resourceful women were more likely to drop out of the self-control program than high resourceful women. Although both the high and low resourceful women who completed the program lost the same amount of weight, only the high resourceful subjects continued to lose weight at follow-up. In contrast, the low resourceful women regained lost weight. Results point to the importance of learned resourcefulness for maintenance of weight loss following a self-control weight program.

Adult↗

New mammalian chloride channel identified by expression cloning.

Ion channels selectively permeable to chloride ions regulate cell functions as diverse as excitability and control of cell volume. Using expression cloning techniques, a complementary DNA from an epithelial cell line has been isolated, sequenced and its putative structure examined by site-directed mutagenesis. This cDNA, encoding a 235-amino-acid protein, gave rise to a chloride-selective outward current when expressed in Xenopus oocytes. The expressed, outwardly rectifying chloride current was calcium-insensitive and was blocked by nucleotides applied to the cell surface. Mutation of a putative nucleotide-binding site resulted in loss of nucleotide block but incurred dependence on extracellular calcium concentration. The unusual sequence of this putative channel protein suggests a new class of ion channels not related to other previously cloned chloride channels.

Amino Acid Sequence↗

Dopamine D1 receptor stimulation of cyclic AMP accumulation in COS-1 cells.

Dopamine is shown to stimulate cAMP accumulation in COS-1 cells via endogenously expressed dopamine D1 receptors. A dissociation of dopamine and beta-adrenoceptor responses is demonstrated by the use of selective antagonists and different desensitization patterns following exposure of the cells to dopamine or the beta-adrenoceptor agonist, isoproterenol. The dopamine response in COS-1 cells exhibits a pharmacological profile similar to that found in dopamine D1 tissues such as rat striatum and fish retina. The presence of DARPP-32 (dopamine- and cAMP-regulated phosphoprotein, Mr 32,000) immunoreactivity in COS-1 cells is shown by Western blotting and is consistent with the endogenous expression of a dopamine D1 receptor in these cells. It is concluded that a dopamine D1 receptor is expressed in COS-1 cells and the implications of this are discussed.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

A68930: a potent agonist selective for the dopamine D1 receptor.

A68930, (1R,3S)-1-aminomethyl-5,6-dihydroxy-3-phenylisochroman HCl, is a potent (EC50 = 2.5 nM), partial (intrinsic activity = 66% of dopamine) agonist in the fish retina dopamine-sensitive adenylate cyclase model of the D1 dopamine receptor. In the rat caudate-putamen model of the D1 dopamine receptor, A68930 is a potent (EC50 = 2.1 nM) full agonist. In contrast, A68930 is a much weaker (EC50 = 3920 nM) full agonist in a biochemical model of the dopamine D2 receptor. The orientation of the 3-phenyl substituent in the molecule is critical for the affinity and selectivity of the molecule towards the dopamine D1 receptor. A68930 also displays weak alpha 2-agonist activity but the molecule is virtually inactive at the alpha 1- and beta-adrenoceptors. When tested in rats bearing a unilateral 6-OHDA lesion of the nigro-neostriatal neurons, A68930 elicits prolonged (greater than 20 h) contralateral turning that is antagonized by dopamine D1 receptor selective doses of SCH 23390 but not by D2 receptor selective doses of haloperidol. In this lesioned rat model, A68930 increases 2-deoxyglucose accumulation in the lesioned substantia nigra, pars reticulata. When tested in normal rats, A68930 elicits hyperactivity and, at higher doses, produces a forelimb clonus.

Adenylyl Cyclases↗

AuthorBase: a database of authoring systems software.

A working prototype database of authoring system software was developed as part of a study of authoring software conducted by the National Library of Medicine. The database and development issues ranging from the scope of the database to what information to document are described. The protype demonstrates that records of reasonable integrity can be derived from vendor supplied information as long as users understand the database is only an initial starting point in searching for authoring software and a resource for becoming generally familiar with the technology.

Authorship↗

A-69024: a non-benzazepine antagonist with selectivity for the dopamine D-1 receptor.

A-69024 HBr, 1-(2-bromo-4,5-dimethoxybenzyl)-7-hydroxy-6-methoxy-2-methyl-1,2,3,4- tetrahydroisoquinoline hydrobromide, is a selective antagonist of the dopamine D-1 receptor. A-69024 HBr shows an apparent affinity toward the D-1 receptor (identified using [125I]SCH 23390) of 12.6 (4.15-38.3) nM (mean (90% CL), n = 3); the apparent affinity toward the D-2 receptor (identified using [3H]spiroperidol is 1 290 (1,200-1,380) nM (n = 3); using [125I]lysergic acid diethylamine to identify the 5-HT1C receptor gives apparent affinity of 17,800 (9,700-32,600) nM (n = 3). In assays of adenylate cyclase activity, A-69024 HBr antagonizes the D-1 receptor with a calculated affinity of 43.9 (17.5-110) nM (n = 5), while the molecule antagonizes the D-2 receptor with a calculated affinity greater than 400 nM. Behavioral studies demonstrate that A-69024 HBr (5 mg/kg s.c.) is able to block both amphetamine-induced locomotor activity and apomorphine-induced stereotypy. Furthermore, A-69024 HBr blocks SF&F 38393-, but not quinpirole-, induced rotation in rats having unilateral 6-hydroxydopamine lesions of the substantia nigra. When administered at behaviorally effective doses. A-69024 HBr neither increases the concentration of serum prolactin nor potentiates dihydroxyphenylalanine (DOPA) accumulation in the caudate-putamen of rats pretreated with the DOPA decarboxylase inhibitor NSD 1015. Because A-69024 is a dopamine receptor antagonist discriminating between the D-1 and D-2 receptors, it may be a useful research tool.

Adenylyl Cyclases↗

Beta-adrenergic blockade in children.

Beta-adrenergic blockers are often used in children to treat a variety of cardiovascular and noncardiovascular medical problems. The clinical experiences with beta-blockers in neonates, children, and adolescents are discussed in this comprehensive review.

Adolescent↗

Perception of expiratory flow by asthmatics and non-asthmatics during rest and exercise.

Perception of respiratory function may be an important factor in self-management of asthma. Previous research has suggested that asthmatics may not accurately perceive pulmonary functioning. The perception of normal and asthmatic individuals was assessed using a magnitude production procedure in a series of three studies, proceeding from normal individuals during rest, then submaximal exercise, to a comparison of normal and asthmatic adolescents during rest and submaximal exercise. At rest there were no differences between males and females, adults and adolescents, or asthmatics and non-asthmatics. However, there were significant differences in perception between rest and exercise for all groups. These findings suggest that a breakdown in perception does not occur during submaximal exercise in patients with asthma.

Adolescent↗

Asthma and bacterial sinusitis in children.

Signs, symptoms, and radiographic abnormalities of sinusitis are frequent in children with asthma; it is not known whether sinus inflammation is associated with bacterial infection or other mechanisms. Eight asthmatic patients with exacerbation of asthma despite bronchodilator therapy were studied after maxillary sinusitis was confirmed by radiographs. All had cough, wheezing, nasal stuffiness, rhinorrhea and were afebrile. Four patients had headaches, and two had facial pain. Maxillary sinus aspirates were obtained, and bacterial cultures were positive in five: Branhamella catarrhalis (2), nontypeable Hemophilus influenzae (2), Streptococcus pneumoniae (1). Nose and throat cultures did not correlate with sinus cultures. All patients received bronchodilators, and four of eight patients received steroids. All were treated for 14 to 28 days with antibiotics during which seven of the eight patients improved clinically including all with positive sinus cultures. Asthma-symptoms diary scores were kept by five; all demonstrated improvement. Pulmonary-function tests improved in five of seven patients after the antibiotic and asthma therapy including the four patients with positive cultures. Sinus radiographs cleared in three, improved in three, and were unchanged in two patients after antibiotic therapy.

Anti-Bacterial Agents↗

Hypogammaglobulinemia with sarcoidlike granulomas.

A 12-year-old girl had sarcoidlike syndrome and hypogammaglobulinemia. Pancytopenia and hepatosplenomegaly were noted at age 4 years. Histopathologic study showed typical sarcoidlike granulomas. Chronic lung disease, along with recurrent infections, developed. Immunologic studies revealed common variable hypogammaglobulinemia, abnormal cellular immune functions, and decreased C4 levels. An immunoregulatory defect is suggested as the pathogenesis of this immunodeficiency syndrome, with multisystem sarcoidlike granulomas, hypersplenism, pulmonary disease, and abnormal cellular and humoral immunity.

Agammaglobulinemia↗

Analysis of the prognosis of minimal and occult breast cancers.

Of 296 occult breast cancers diagnosed at Kaiser-Permanente Medical Center, Los Angeles, in the last ten years, 80 were classified as minimal and 167 as nonminimal. Minimal cancers were intraductal, lobular in situ, or invasive and 0.5 cm or less in diameter. In the occult-minimal group, no woman had axillary node metastases, and there were no recurrences. In the occult-nonminimal group, 26% of the patients had axillary nodal involvement, with a recurrence rate of 13% and a mortality of 11.6%. Occult breast cancers differed significantly between minimal and nonminimal tumors in both treatment and prognosis. Nonminimal cancers should be treated as any palpable carcinoma. More conservative approaches could be considered for the minimal group, but prospective controlled studies should be done to determine the long-term risks of such treatment.

Breast Neoplasms↗