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C Atkins

Publications and source records attributed to C Atkins.

At least 19 recordsLinked to original sources
PubMed1999

Enhanced replication of M-tropic HIV-1 strains in Herpesvirus saimiri immortalised T-cells which express CCR5.

A better characterisation of mononuclear cell-tropic (M-tropic) HIV-1 is central to disease control as these viruses predominate in disease transmission. M-tropic viruses do not replicate in conventional T-cell lines, and virus titres obtained in peripheral blood mononuclear cells (PBMC) are low. Human T-lymphocytes which have been immortalised by Herpesvirus saimiri strain C488 (HVS T-cells) are highly permissive to the replication of T-cell tropic strains of HIV. This study aimed to determine if HVS T-cells support replication of M-tropic HIV isolates that have not been adapted to conventional T-cell lines. A panel of PBMC low passage/primary field isolates and their molecular clones was used. Results show that infection in HVS T-cells was longer lived than in PBMC. In terms of peak virus titre and duration of productive infection, the two HVS T-cell lines studied were superior to PBMC, and one supported enhanced replication of all M-tropic isolates. This is important for generating M-tropic virus pools of sufficient titre for further biological studies such as virus neutralisation, co receptor usage and testing of antivirals. Phenotypic analysis showed that HVS T-cells are CD4+-activated memory cells expressing both CXCR-4 and CCR5 co receptors. Thus, HVS immortalisation appears to select for the T-cell subset targeted by HIV-1 in vivo.

CD4-Positive T-Lymphocytes↗
PubMed1999

Multipotential progenitors of the mammalian enteric nervous system capable of colonising aganglionic bowel in organ culture.

The enteric nervous system of vertebrates is derived from neural crest cells that invade the gut wall and generate a highly organised network of enteric ganglia. Among the genes that play an important role in ENS development is c-Ret, mutations of which result in failure of formation of enteric ganglia (intestinal aganglionosis). To further understand the development of the mammalian ENS in general and the mechanism of action of the RET RTK in particular, we have developed and used an organotypic culture system of mouse fetal gut. At the stage of culture initiation, the gut is partially populated by undifferentiated ENS progenitors, but culture for several days results in extensive neuronal and glial differentiation. Using this organ culture system, we have compared the development of the ENS in wild-type and RET-deficient gut and showed that the aganglionic phenotype observed in vivo is consistently reproduced under the in vitro culture conditions. Microinjection of RET+ cells isolated from E11.5 mouse bowel into wild-type or RET-deficient aganglionic gut in organ culture, results in extensive repopulation of their wall by exogenously derived neurons and glia. Finally, using a similar approach, we demonstrate that single RET+ cells introduced into the wall of wild-type gut generate both cell lineages of the ENS, i.e. neurons and glia. Our data show the NC-derived RET+ population of fetal gut in mammalian embryos consists of multipotential progenitors capable of colonising efficiently both wild-type and RET-deficient aganglionic bowel in organ culture.

Animals↗
PubMed1998

Skills training for pregnancy and AIDS prevention in Anglo and Latino youth.

PURPOSE: This study tested social skills training (SST), didactic training (DT), and no training (NT) on adolescents' social skills for resisting peer pressure to engage in acquired immunodeficiency syndrome (AIDS) and pregnancy risk behavior. METHODS: A total of 307 Latino and Anglo youth ages 13-18 years were assigned at random to receive 18 h of SST, 18 h of DT, or NT. RESULTS: Significantly (p < 0.05) greater increases in assertiveness followed SST compared to DT or NT for three trained skills: condom negotiation, asking a friend about their sex/drug history, and discussing a friend's risk of AIDS. Untrained negotiation skills (e.g., purchasing a condom) did not increase significantly. SST did not result in increased assertiveness for refusal skills. DT increased knowledge of AIDS significantly more than SST; both DT and SST increased knowledge significantly more than NT. CONCLUSIONS: Social skills training can increase assertiveness for certain negotiation skills that may decrease risk of AIDS for Latino, Anglo, and male and female adolescents. Both DT and SST can increase knowledge of AIDS prevention. Differences between experimental groups were supported by differences between trained and untrained skills within the SST condition, adding to discriminant validity.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Glomerular filtration rate in children following renal transplantation.

Most studies evaluating renal function post-renal transplantation in children have used serum creatinine (S(Cr)) or estimates of its clearance (C(SCH)). When renal function is impaired both S(Cr) and the C(SCH) overestimate glomerular filtration rate (GFR), especially during cyclosporine therapy. This study measured GFR in 64 children (age range: 4-19 years) with stable renal function who received renal allografts at the Childrens Medical Center of Dallas, 31 from live related donors (LRD) and 33 from cadaveric donors (CAD). 125I-iothalamate clearance (C(IO)) was used as the reference standard for measuring GFR. Data from 100 C(IO) studies, were analyzed and results reported as mean +/- S.E.M. C(IO) performed during the first year after renal transplantation in 23 children who received allografts from LRD was 72.4+/-5.5 ml/min per 1.73 m2 compared to 50.4+/-7.4 ml/min per 1.73 m2 in 18 children who received allografts from CAD (p<0.05). Beyond the first year post-renal transplantation there was no difference in C(IO) between LRD and CAD allografts. When S(Cr) was compared to C(IO), the relationship was nonlinear. C(IO) was also compared to the simultaneous estimation of creatinine clearance by C(SCH). The overestimation of GFR by C(SCH) was inversely proportional to the level of renal function. When renal function was normal or mildly reduced (C(IO) > 50 ml/min per 1.73 m2), C(SCH) closely approximated C(IO). When renal function was moderately to severely curtailed (C(IO) < or = 50 ml/min per 1.73 m2), C(SCH) overestimated C(IO) by 43.6+/-5.6%. The study concludes that in children with renal transplant: 1) C(IO) is higher in allografts from LRD compared to CAD kidneys only in the first 12 months following renal transplantation; 2) S(Cr) is a poor predictor of C(IO); and 3) C(SCH) consistently overestimates GFR children following renal transplantation unless renal function is normal or only mildly decreased.

Adolescent↗
PubMed1997

A re-evaluation of the effects of X-linked immunodeficiency (xid) mutation on B cell differentiation and function in the mouse.

CBA/N (xid) mice have a point mutation in Bruton's tyrosine kinase (btk), which results in their failure to respond to T-independent type 2 (TI-2) antigens, and to several B cell mitogens [most notably anti-immunoglobulin (Ig)] in vitro. They have reduced numbers of peripheral (B2) B cells, which are regarded as being phenotypically and functionally immature. We show here that adult CBA/N mice in fact have two distinct B cell populations: some 60% of the cells are CD23+ HSAlo sIgDhi and hence resemble recirculating, follicular (RF) B cells from normal mice, except that they are sIgMhi. The remaining 40% of xid B cells are CD23- HSAhi sIgD-/lo and resemble immature transitional (TR) B cells. TR B cells from xid mice do not synthesize DNA when cultured with lipopolysaccharide (LPS), whereas those from normal mice do so. Only the RF cells from either xid or normal mice proliferate in response to ligation of CD40. In neonatal normal mice the emergence of mitogen responsiveness followed the chronological sequence LPS-->anti-CD40-->anti-Ig approximately anti-CD38. The same developmental sequence was seen with B cells from xid mice (for LPS and anti-CD40), but it occurred at a significantly slower tempo and this correlated with the later appearance of RF-type cells. TR xid B cells express very low levels of bcl-2 and we conclude that these cells resemble very immature (bone marrow) B cells, rather than normal transitional cells. We, therefore, propose that the xid mutation imposes a multistage brake on B cell differentiation in the mouse. The available data suggest that btk is required for the positive selection of B cells throughout their differentiation in the periphery. This in turn implies that low level signaling via surface Ig is needed throughout this process in order for peripheral B cells to become functionally mature.

Animals↗
PubMed1997

Herpesvirus saimiri-immortalized human T-cells support long-term, high titred replication of human immunodeficiency virus types 1 and 2.

Herpesvirus saimiri strain C488 transforms human CD4+ T-lymphocytes to continuous interleukin-2-dependent growth. Unlike human T-cell lines derived from tumours or those transformed by human T-lymphotropic virus 1, herpesvirus saimiri-immortalized T-cells (HVS T-cells) retain many functions of primary activated T-lymphocytes. We have characterized the course of human immunodeficiency virus types 1 and 2 (HIV-1/-2) infection in three HVS T-cell lines. Our results confirm that HVS T-cells are highly permissive to both HIV-1/-2 prototype viruses and to poorly replicating HIV-2 strains of restricted cell tropism. However, the infection was persistently productive for up to 5 months. The down-regulation of surface CD4 molecules was delayed and virus yields significantly exceeded those obtained in T-cell lines.

CD4 Antigens↗
PubMed1996

Antigen-driven shedding of L-selectin from human gamma delta T cells.

Activation of lymphocytes leads to the modulation of a number of surface molecules. We have investigated the expression of one such molecule. L-selectin, following activation of gamma delta T cells with Mycobacterium tuberculosis. L-selectin is modulated during lymphocyte entry into lymph nodes; this modulation reflects the recirculation and homing potential of lymphocytes. We find that stimulation of gamma delta T cells by M. tuberculosis antigens results in shedding of L-selectin from gamma delta T cells. Re-expression of L-selectin occurs on removal of antigen suggesting that the regulation of expression is controlled by the presence or absence of antigen. The gamma delta T-cell receptor (TCR)-positive, L-selectin negative population of peripheral blood lymphocytes appears to be resting cells, as assessed by forward- and light-scatter analysis. We further find that gamma delta T cells isolated from a site of infection, the pleural fluid of a tuberculosis patient, are L-selectin negative, and that L-selectin is re-expressed following culture of the pleural fluid gamma delta T cells in the absence of antigen. These results demonstrate that, in addition to stimulation with polyclonal mitogens, antigen stimulation can also promote the surface shedding of L-selectin and that gamma delta T cells have the potential to home to sites of infection supporting their role in the immunological defence against infectious micro-organisms.

Antigens, Bacterial↗
PubMed1993

Developmental changes in the molecular forms of acetylcholinesterase during the life cycle of the lamprey Petromyzon marinus.

1. We have determined the molecular forms of acetylcholinesterase (AChE) present in the skeletal muscle of the lamprey during the adult parasitic stage of its life cycle. AChE was found primarily in the globular G4 form, as well as in the asymmetric forms A4, A8 and A12. 2. We compare the complement of molecular forms present in skeletal muscle during the larval, parasitic, and spawning stages of the lamprey life cycle. The larval form, the ammocoete, contains elevated amounts of G1 and G2. However, the most striking change that we observed was in the proportion of asymmetric forms of AChE present: 5% in the ammocoete, 28% in the parasite and 9% in the spawner. 3. We speculate that these differences may be related to the physiological states of the lamprey during the various stages of its life cycle.

Acetylcholinesterase↗
PubMed1993

Glomerular filtration rates in persons evaluated as living-related donors--are our standards too high?

We have retrospectively analyzed the glomerular filtration rate by 125-I iothalamate clearance and creatinine clearance in a group of 661 persons evaluated as potential kidney donors. The average GFR in this population is lower than that reported in previous studies and ranges from 102 +/- 15 and 114 +/- 17 ml/min for males and females age 21-30 to 84 +/- 13 and 79 +/- 15 ml/min for males and females age 51-60. Furthermore, there has been a gradual decrease in GFR in this population from 1970 to 1990 in both the entire population and in those under the age of 40. The cause of this drop is not apparent. These data can be utilized to determine the appropriateness of a potential donor for donation, and may indicate that our current standards are too high.

Adult↗
PubMed1992

Individual performance review--meeting staff needs.

One of the main components of job satisfaction is the recognition of one's achievements. It can be argued that nursing has been slow to recognise the positive effects of honest feedback on individual performance. Individual Performance Review (IPR) or staff appraisal is one way of providing that feedback.

Employee Performance Appraisal↗
PubMed1991

Pregnancy, STDS, and AIDS prevention: evaluation of New Image Teen Theatre.

New Image Teen Theatre combines peer education and theatre in an informative and entertaining package. This study was undertaken to assess the effectiveness of New Image Teen Theatre on altering teenagers' attitudes, knowledge, and intentions regarding sexual behavior. A total of 143 adolescents between the ages of 13 and 19 viewed the performance. The performance focused on the prevention of pregnancy, AIDS, and STDs and included content aimed at increasing communication. Teen participants completed pretest and posttest questionnaires. Almost half of the adolescents reported having engaged in sexual intercourse. About one third of the sexually active reported never using birth control, and only 21% reported consistent use of condoms. These results confirm adolescents' risk for pregnancy, STDs, and AIDS in particular. Following the performance, the teens reported significantly more willingness to discuss sexual issues with others, significantly greater intention to use birth control (for sexually active teens), and demonstrated significantly greater sexual knowledge. Furthermore, they indicated that they had experienced more positive emotions than negative emotions while viewing the production. Results suggest that theatre education may set the stage for more comprehensive interventions designed to prevent pregnancy, STDs, and AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

The clinical nurse anesthetist as diagnostic sleuth.

Two cases are presented where observations made during anesthetic management led to appropriate diagnoses that otherwise might not have occurred in a timely fashion. In the first case, an early diagnosis of myasthenia gravis was facilitated; while in the second case, an improbable response led to rethinking of the initial diagnosis. The role of the nurse anesthetist in being alert to the consequences of unusual clinical and theoretical responses on behalf of the patient is depicted.

Adult↗
PubMed1989

Prevention of tobacco use among adolescents in public schools in San Diego County, U.S.A.

Project S.H.O.U.T. (which stands for "Students Helping Others Understand Tobacco") is a tobacco-use prevention project funded by the United States National Cancer Institute for preventing the use of cigarettes and smokeless tobacco (snuff and chewing tobacco) in public schools in San Diego County, California. Based on principles of behavior modification, Project S.H.O.U.T. teaches students how to anticipate and overcome negative peer pressure to use tobacco and reinforces them for having done so. Preliminary results indicate that the prevalence of tobacco use among students receiving peer pressure resistance skills training was somewhat but not statistically significantly lower than the control group after one year of intervention. In addition, students in a third lottery condition, who were reinforced for simply not using tobacco, showed lower prevalence rates compared to controls. Additional support for the efficacy of the intervention program was provided by the refusal skills assessment test, which indicated that students exposed to the intervention were able to refuse tobacco offers more effectively than the control students. Our results indicate that tobacco use prevention experts should do more than provide decision-making and behavioral skills for resisting tobacco use, but should also reinforce the non-use of tobacco.

Adolescent↗
PubMed1988

Structure-activity profile of a series of novel triazoloquinazoline adenosine antagonists.

During a search for benzodiazepine receptor modulators, a highly potent adenosine antagonist (CGS 15943) was discovered. The compound was defined as a resonance-stabilized hybrid of the canonical structures 9-chloro-2-(2-furyl)[1,2,4]triazolo[1,5-c]quinazolin-5-amine (2a) and 9-chloro-2-(2-furyl)-5,6-dihydro[1,2,4]triazolo[1,5-c]-quinazolin- 5-imine (2b). Spectroscopic evidence and chemical reactivity in polar media favor the amine form 2a as the major contributor of the two canonical structures. The synthesis of 2 and some of its analogues and the structure-activity relationships in four biological test systems are described. Replacement of the 9-chloro group by hydrogen, hydroxyl, or methoxyl gave compounds with comparable binding potency at the A1 and A2 receptors but much less activity as antagonists of 2-chloroadenosine in guinea pig tracheal strips. Alkylation of the 5-amino group caused, in general, a loss of binding activity, particularly at the A2 receptor, as well as complete loss of activity in the tracheal model. Modification of the 2-furyl group caused a pronounced loss of activity in all of the test systems.

Adenosine↗
PubMed1988

Rheumatic disease in the Nuu-Chah-Nulth native Indians of the Pacific Northwest.

The Nuu-Chah-Nulth are a tribe of 2,300 Pacific Northwest native Indians. A retrospective study has identified 157 requiring referral to rheumatologists over 15 years. Rheumatoid arthritis (RA) was found in 23, systemic lupus erythematosus (SLE) in 8, sacroiliitis 5, and Reiter's syndrome 1. Overlap syndromes with combinations of RA, SLE, scleroderma and polymyositis were seen in 9. Other rheumatic disorders included osteoarthritis 10, soft tissue rheumatism 14, and musculoskeletal complaints of known etiology (trauma, infection, neoplasm) 12. The remaining 75 patients suffered from periodic weather dependent joint swelling (52) or polyarthralgia (23) which were sometimes accompanied by features of systemic connective tissue disease. These findings are compared with rheumatic disease in other North American Indians.

Antibodies, Antinuclear↗
PubMed1987

Best of both worlds.

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Appointments and Schedules↗