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K Hanson

Publications and source records attributed to K Hanson.

At least 37 records · Page 2Linked to original sources
PubMed1997

Attenuation of phytochrome A and B signaling pathways by the Arabidopsis circadian clock.

In higher plants, environmental cues such as light signals are integrated with circadian clock signals to control precisely the daily rhythms observed for many biological functions. We have used a fusion of the promoter of a chlorophyll a/b binding protein gene, CAB2, with firefly luciferase (cab2::luc) to monitor the detailed kinetics of transcription in response to photoreceptor activation in Arabidopsis. Using this marker in phototransduction and circadian-dysfunctional mutants, we studied how signals from phytochrome and the circadian clock are integrated for the regulation of CAB2 transcription. Results from these mutant studies demonstrate that similar expression features, namely, the acute and circadian responses, are present in both etiolated and green seedlings and that the acute and circadian responses are genetically separable. We also demonstrate that persistent Pfr signaling occurs in red light-pulsed etiolated seedlings, which suggests that the circadian clock antagonizes Pfr-mediated signal transduction. Based on these genetic studies, we propose a model for the regulation of CAB2 transcription in which individual photoreceptors and phototransduction components have been assigned to specific pathways for the regulation of discrete kinetic components of the CAB2 expression pattern.

Arabidopsis↗
PubMed1996

Inhibition of cyclic 3'-5'-guanosine monophosphate-specific phosphodiesterase selectively vasodilates the pulmonary circulation in chronically hypoxic rats.

While it is known that nitric oxide (NO) is an important modulator of tone in the hypertensive pulmonary circulation, the roles of cyclic 3'-5'-guanosine monophosphate (cGMP) and cGMP-phosphodiesterase (PDE) are uncertain. We found that isolated lung perfusate levels of cGMP were over ninefold elevated in hypertensive vs. normotensive control rats. 98-100% of lung cGMP hydrolytic activity was cGMP-specific PDE5, with no significant decrease in PDE activity in hypertensive lungs, suggesting that the elevation in cGMP was due to accelerated production rather than reduced degradation. In pulmonary hypertensive rat lungs, in vitro, cGMP-PDE inhibition by E4021[1-(6-chloro-4-(3,4-methylbenzyl) amino-quinazolin-2-yl)piperdine-4-carboxylate], increased perfusate cGMP threefold, reduced hypoxic vasoconstriction by 58 +/- 2%, and reduced baseline pulmonary artery pressure by 37 +/- 5%. In conscious, pulmonary hypertensive rats, intravenous administration of E4021 reduced hypoxic vasoconstriction by 68 +/- 8%, pulmonary artery pressure by 12.6 +/- 3.7% and total pulmonary resistance by 13.1 +/- 6.4%, with no significant effect on cardiac output, systemic pressure, and resistance. Comparison of E4021 to inhaled nitric oxide demonstrated that cGMP-PDE inhibition was as selective and as effective as inhaled NO.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1996

"Doin' politics": linking policy and politics in nursing.

Policies affecting nursing are set within the larger environment of the health policy sector. That sector is characterized by increasing size, complexity, and goal displacement. All three characteristics have served to expand the resource base for this sector despite fiscal constraints on such growth. The environment of policy making shapes both the substance of policy change and the strategies for political adoption. Without understanding the dynamics of the policy environment, efforts by nursing leaders to enhance their growing political sophistication and to articulate nursing interests with maximum effectiveness will be compromised.

Decision Making, Organizational↗
PubMed1995

Identification of the porcine intestinal accessory factor that enables DNA sequence recognition by vitamin D receptor.

The nuclear accessory protein in porcine intestinal nuclear extracts that activates the binding of the vitamin D receptor to its vitamin D response elements has been highly purified. It contains a protein that binds 9-cis-[3H]retinoic acid, was detected on immunoblots with an anti-retinoid X receptor (RXR) peptide antibody, and supports the binding of retinoic acid receptor gamma to the retinoic acid receptor beta gene response element. Most important, the two specific complexes formed by porcine nuclear extract with the vitamin D response elements from either the osteocalcin gene or the rat 24-hydroxylase gene are shifted to a larger complex by both an anti-vitamin D receptor antibody and an anti-RXR antibody, leaving no doubt that in vivo the nuclear accessory factor for the vitamin D receptor in the intestine is an RXR protein.

Animals↗
PubMed1995

The impact of infectious diseases on the health of U.S. troops deployed to the Persian Gulf during operations Desert Shield and Desert Storm.

An assessment was conducted of the impact of infectious diseases on the 697,000 U.S. troops deployed to the Persian Gulf during 1990-1991 in Operations Desert Shield and Desert Storm. The incidence of nonbattle injuries, including infectious diseases, during this conflict was lower than during previous wars involving U.S. military personnel. The major reported causes of morbidity were generally mild cases of acute diarrheal and upper respiratory disease. The most unexpected outcome was the lack of arboviral infections, particularly sandfly fever, and the occurrence among U.S. troops of 12 cases of visceral leishmaniasis due to Leishmania tropica. The fact that infectious diseases were not a major cause of lost manpower, in sharp contrast to the experience among military personnel in World War II, can be attributed to a combination of factors: the presence of a comprehensive infrastructure of medical care, extensive preventive medicine efforts, and several fortuitous circumstances. Beneficial conditions that may not be present in future conflicts in this region include isolation of most combat troops to barren desert locations during the cooler, winter months, which provided the least favorable conditions for transmission of arthropod-borne diseases.

Animals↗
PubMed1994

Methodological issues in the administration of multiple doses of smoked cocaine-base in humans.

Many methodological issues exist in human laboratory research with smoked cocaine-base that include safety, precision of dose delivery of smoked cocaine, and the lack of an adequate placebo. All of these issues are particularly apparent with studies involving multiple doses of cocaine. Addressing these concerns is important in conducting parametric studies that require examining dose-response effects. The purposes of this study were to determine: 1) the safest interval between doses to deliver smoked cocaine; 2) the accuracy or reproducibility of administering precise and multiple doses of cocaine; 3) the potential for using a control dose of cocaine; and 4) the influence of multiple doses on these parameters. Six black males were given 10 doses of either 5 or 35 mg of cocaine-base at 15-, 30-, and 45-min intervals. The dependent measures included physiological, subjective, and performance responses. These measures were taken prior to dosing and at specific time intervals after each dose of smoked cocaine. The results showed: 1) dosing at 30-min intervals allowed sufficient time for recovery of blood pressure and heart rate to permit up to 10 doses to be safely administered; 2) reproducible blood cocaine levels were obtained with repeated dosing using a heated wire-coil device; 3) significant differences were observed between the 5- and 35-mg dose with 5 mg being a low enough dose to produce minimal effects; 4) acute tolerance was evidenced with multiple doses of cocaine for most of the measures; and 5) considerable between- and within-subject variability was observed in the pattern of responses to cocaine.

Administration, Inhalation↗
PubMed1994

Transition to retirement: gender differences.

The present investigation consisted of two studies which attempted: 1) to assess the replicability of the investigation by Wapner and Hornstein [1] and Hornstein and Wapner [2,3] that uncovered four distinct modes of experiencing the transition to retirement, and 2) to advance that work by focusing on gender differences. The preliminary study, based on analyses of twenty-four case studies reported by Wapner and Hornstein suggested it would be profitable to study gender differences in a more systematic manner [1]. Toward this end, the major study involved construction of four appropriate instruments which were administered to ninety-four (48 women, 46 men) recent retirees. The four retirement categories (I. Transition to Old Age; II. New Beginning; III. Continuation; IV. Imposed Disruption) described in those investigations was replicated. Moreover, striking gender differences emerged. Theoretical and practical implications of the study were explored.

Adaptation, Psychological↗
PubMed1993

Evidence for unusual stability of ADP-ribosyl linkage to membrane proteins of a murine leukemic cell line.

A set of membrane proteins from murine myelomonocytic leukemia cell line WEHI-3BD+ was found to be ADP-ribosylated. Both this ADP-ribosylation reaction and granulocytic differentiation in response to recombinant G-CSF were inhibited approximately 50% by 2 mM benzamide, suggesting a correlation between these two processes. The stability of the ADP-ribosyl linkage was examined under a series of chemical release conditions and was found to resemble none of the known ADP-ribosyl-amino acid linkages. This chemical modification may represent a new class of mono(ADP-ribosyl) modifications of proteins.

Adenosine Diphosphate Ribose↗
PubMed1993

Ca2+ and endonuclease activation in radiation-induced lymphoid cell death.

Exposure of lymphoid cells to X-irradiation caused an increase in cytosolic Ca2+ ([Ca2+]i) in rat thymocytes but not in rat splenocytes. The Ca2+ elevation in rat thymocytes was transitory and by 2 h postirradiation, when the chromatin degradation began to be appreciable, the [Ca2+]i had returned to control level. Inhibitors of RNA and protein syntheses prevented the radiation-induced [Ca2+]i rise in thymocytes. Pretreatment of both cell types with Ca2+ chelators also prevented DNA fragmentation, chromatin condensation, and cell death caused by X-irradiation. These data suggest that Ca2+ plays an important role in the perpetuation of apoptosis in both thymocytes and splenocytes although a Ca2+ elevation, which may serve as a signal in thymocytes, does not appear to be required to initiate radiation-induced DNA fragmentation in splenocytes.

Animals↗
PubMed1993

Community financing of health care in Africa: an evaluation of the Bamako initiative.

The Bamako Initiative, a controversial attempt to strengthen Primary Health Care using community financing and community participation and management was launched at a meeting of African Ministers of Health in 1987. This evaluation focuses particularly on the community financing aspects of the Initiative. Previous experiences of community financing highlight particular lessons for the development of the Initiative and issues likely to be encountered in implementation attempts. Four country case studies of the Initiative at its early stages of implementation (in June, July and August 1991) were conducted in Burundi, Guinea, Kenya, and Nigeria. Similar activities in Uganda were also studied. These were short studies of one month each and utilised methods of rapid evaluation. The studies aimed to direct implementers quickly to issues requiring attention rather than to reach overall conclusions regarding the success of the Initiative which would be premature at this stage. Price structures used by the Initiative need to consider the access of marginalised groups more than is the case at present. In addition, there is a need to ensure against over-prescription and commercialisation and to ensure that incentives for utilising most appropriate levels of care are maintained. The evidence suggests that most people do find amounts of money to pay for health services which are large in relation to their income. This is probably a tribute to extensive community support mechanisms. Nevertheless, it highlights the plight of those who fall through this safety net for whom even charges for very basic care may be prohibitive. On the other hand, it appears that in most cases, the Initiative's activities provide a service which is cheaper when all costs to the household are taken into account, than was available before. The quality of services included in the Initiative's activities in the five countries was highly variable. Success in raising substantial revenues has also been mixed. In some countries however, substantial funds have been generated and used to achieve real improvements in health services. Overall, the experiences of the five countries appear to have been highly dependent on a number of 'environmental' characteristics: a tradition or not of 'free' services; the adequacy of current resource availability and that immediately preceding the introduction of the Initiative; the existing stage and nature of decentralisation within the country; and the competition the Initiative's activities face with alternatives.

Burundi↗
PubMed1992

Esophageal pseudodiverticulosis: two new cases in children.

Esophageal intramural pseudodiverticulosis (EIPD) is an uncommon entity in which distended esophageal mucous glands form flask-like outpouchings from the esophagus. Its relationship with esophagitis, gastroesophageal reflux, and benign stricture suggests that it is a consequence of inflammation.

Child↗
PubMed1992

Familial risk factors to oppositional defiant disorder and conduct disorder: parental psychopathology and maternal parenting.

In a sample of 177 clinic-referred children aged 7-13, an association was found between a diagnosis of conduct disorder (CD) and several aspects of family functioning: maternal parenting (supervision and persistence in discipline) and parental adjustment (paternal antisocial personality disorder and paternal substance abuse). Children with oppositional defiant disorder (ODD) were intermediate to families of children with CD and clinic control children on all variables, but differed from control children only in having a higher rate of paternal substance abuse and paternal antisocial personality disorder (APD). When both parental APD and deviant maternal parenting were entered into 2 x 2 logit-model analyses predicting CD, only parental APD was significantly associated with CD, and no interactions between parental adjustment and maternal parenting were found. The importance of these findings for understanding the etiology of CD and for disentangling correlated risk factors in future studies is discussed.

Antisocial Personality Disorder↗
PubMed1992

AIDS: what does economics have to offer?

AIDS is rapidly becoming a major health problem in developing countries. Limited empirical information is available about the impact of AIDS on the household, the community, the health sector and the broader economy. Special problems exist in estimating the direct economic costs of AIDS in developing countries, including large out-of-pocket expenditures on health care and shortages of drugs and supplies; the difficulties of valuing resources used in caring for people with AIDS; and the lack of treatment alternatives. The calculation of indirect costs is complicated by difficulties in calculating the value of non-market production and international comparisons of the value of healthy life years lost may be erroneous, due to the higher level of average wages in developed countries. Existing evidence on the impact of AIDS at the household, community, sectoral and macroeconomic level is reviewed. Special attention is given to the impact of AIDS on the health sector and the resource allocation decisions which are made at this level. A policy-relevant research strategy would include addressing the particular information needs of the health sector, as well as studies which can help to inform government policy to mitigate the impact of AIDS at the household, community, sectoral and macroeconomic levels.

Acquired Immunodeficiency Syndrome↗