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K Moore

Publications and source records attributed to K Moore.

At least 73 records · Page 4Linked to original sources
PubMed2000

The high oleate trait in the cultivated peanut [Arachis hypogaea L]. II. Molecular basis and genetics of the trait.

A peanut variety with high oleate content has previously been described. When this high oleate variety was used in breeding crosses, the F2 segregation ratio of high oleate to normal oleate progeny was 3:1 or 15:1 depending on the normal oleate varieties used in the crosses. These data suggested that the high oleate trait is controlled by two recessive genes, and some peanut varieties differ from the high oleate variety by mutations in one gene, while others differ by mutations in two genes. The objective of this study was to understand the molecular nature of the high oleate trait and the various segregation patterns. In the previous paper in this issue, we reported that the level of transcripts expressed by one (ahFAD2B) of two homoeologous genes for oleoyl-PC desaturases in cultivated peanut is significantly reduced in high oleate varieties. In this report, we examined gene expression by RT-PCR/restriction digestion in a cross that shows a one-gene segregation pattern for the high oleate trait. Our data showed that the severely reduced level of ahFAD2B transcript correlates absolutely with the high oleate phenotype in this cross, suggesting that the single gene difference is correlated with the ahFAD2B transcript level. When we tested the enzyme activity of the proteins encoded by ahFAD2A and ahFAD2B by expression of the cloned sequences in yeast, only the ahFAD2B gene product showed significant oleoyl-PC desaturase activity. These data, combined with the observation that ahFAD2A shows a change (D150N) in a residue that is absolutely conserved among other desaturases, raised the possibility that the ahFAD2A in these normal and high oleate lines is a mutant allele. In support of this hypothesis, we found that another ahFAD2A allele in a normal oleate peanut line does not have the D150N change. This peanut line displays a two-gene-segregation pattern for the high oleate trait. In conclusion, our results suggest that a mutation in ahFAD2A and a significant reduction in levels of the ahFAD2B transcript together cause the high oleate phenotype in peanut varieties, and that one expressed gene encoding a functional enzyme appears to be sufficient for the normal oleate phenotype.

Alleles↗
PubMed2000

The high oleate trait in the cultivated peanut [Arachis hypogaea L.]. I. Isolation and characterization of two genes encoding microsomal oleoyl-PC desaturases.

Plant oils rich in oleate are considered superior products compared to oils rich in polyunsaturated fatty acids. Peanut (Arachis hypogaea L.) is one of the major oilseed crops, and high oleate mutant varieties with as much as 85% oleate have been reported. We examined the possibility that this mutant phenotype resulted from reduction in the activity or the transcript level of microsomal oleoyl-PC desaturase. Two independently generated high oleate mutants, M2-225 and 8-2122, and their partially isogenic lines with a normal oleate phenotype were used in this study. Two cDNA sequences coding for microsomal oleoyl-PC desaturases, ahFAD2A and ahFAD2B, have been isolated from the developing peanut seed with a normal oleate phenotype. Cultivated peanut is an allotetraploid, and sequence comparisons with the genes from the putative diploid progenitor species suggested that ahFAD2A and ahFAD2B are non-allelic, but homeologous genes originating from two different diploid species. Northern analysis showed that the transcripts of oleoyl-PC desaturases are highly abundant in both normal and high oleate peanut seeds in the second stage of development. Differential digestion of the RT-PCR products revealed a restriction site polymorphism between ahFAD2A and ahFAD2B, and allowed us to examine the level of transcript expressed from each gene. The results indicate that ahFAD2A is expressed in both normal and high oleate peanut seeds, but the steady state level of the ahFAD2B transcript is severely reduced in the high oleate peanut varieties. These data suggested that the reduction in ahFAD2B transcript level in the developing seeds is correlated with the high oleate trait.

Amino Acid Sequence↗
PubMed2000

Access to emergency contraception.

OBJECTIVE: To evaluate access to emergency contraception among women seeking help from clinicians who registered to be listed on the Emergency Contraception Hotline (1-888-NOT-2-LATE, ie, 1-888-668-2528) and the Emergency Contraception Website (not-2-late.com). METHODS: Two college-educated investigators posing as women who had a condom break the previous night called 200 providers to seek help. RESULTS: Only 76% of attempts resulted in an appointment or telephone prescription from a hotline provider within 72 hours, 14% were failures, and 11% resulted in referrals to other providers not listed on the hotline or website. CONCLUSION: Even under ideal conditions, access to emergency contraception is currently constrained. Although emergency contraception could reduce significantly the incidence of unintended pregnancy and the consequent need for abortion, its potential will not be realized unless women have better access to clinicians who can prescribe emergency contraceptive pills.

Contraceptives, Oral, Combined↗
PubMed2000

Alginates from wound dressings activate human macrophages to secrete tumour necrosis factor-alpha.

Alginates are used to manufacture a number of wound dressings. Clinical observations indicate that they may initiate or accelerate healing of chronic wounds after treatment of underlying pathology. Wound granulation tissue contains large numbers of macrophages and they are thought to regulate the healing process. As purified alginates have been demonstrated to activate macrophages this study was initiated to determine whether alginates present within wound dressings may interact with wound macrophages. Alginate fibres taken from four commercially available dressings were co-cultured with the human histiocytic lymphoma cell line U937 following its differentiation with PMA. Activation was assessed by measurement of TNFalpha production. Two of the dressings, Seasorb and Tegagen, had a minimal effect whilst Sorbsan at 1 mg/ml induced 302 + 19 pg/ml TNFalpha. This effect was inhibited by polymyxin B indicating that activation was due to endotoxin contamination. Kaltostat induced production of 839 + 36 pg/ml TNFalpha. This effect was induced both by polymyxin inhibitable endotoxin and a direct interaction with the alginate fibres. These data indicate that some alginate containing dressings have the potential to activate macrophages within the chronic wound bed and generate a pro-inflammatory signal which may initiate a resolving inflammation characteristic of healing wounds.

Alginates↗
PubMed2000

Langerin, a novel C-type lectin specific to Langerhans cells, is an endocytic receptor that induces the formation of Birbeck granules.

We have identified a type II Ca2+-dependent lectin displaying mannose-binding specificity, exclusively expressed by Langerhans cells (LC), and named Langerin. LC are uniquely characterized by Birbeck granules (BG), which are organelles consisting of superimposed and zippered membranes. Here, we have shown that Langerin is constitutively associated with BG and that antibody to Langerin is internalized into these structures. Remarkably, transfection of Langerin cDNA into fibroblasts created a compact network of membrane structures with typical features of BG. Langerin is thus a potent inducer of membrane superimposition and zippering leading to BG formation. Our data suggest that induction of BG is a consequence of the antigen-capture function of Langerin, allowing routing into these organelles and providing access to a nonclassical antigen-processing pathway.

Amino Acid Sequence↗
PubMed2000

Review article: pharmacological treatment of the hepatorenal syndrome in cirrhotic patients.

Renal failure is common in patients who are dying from end-stage cirrhosis, developing in 40-80% of all patients. Where there is no anatomical or pathological cause for the renal failure, it is termed the hepatorenal syndrome. When the hepatorenal syndrome develops, it will only recover when there is some degree of improvement in liver function. Thus for most patients this will occur only after liver transplantation, although the transplantation mortality is increased in this group. Hepatorenal syndrome is a common complication of alcoholic hepatitis, and this group is unusual in that with time and abstinence, significant recovery of liver function may occur. There is therefore a need for supportive therapy to allow time for some recovery of liver function in patients with alcoholic hepatitis and hepatorenal syndrome. Similarly, patients may need support whilst waiting for liver transplantation. This article reviews the pathophysiology and treatment of hepatorenal syndrome.

Disease Progression↗
PubMed2000

The role of lymphocytes in human dermal wound healing.

BACKGROUND: Animal experimental data indicate a requirement for functionally active T lymphocytes to allow optimal healing of dermal wounds. Little evidence exists to confirm that this is the case in humans. Lymphocyte involvement in regulation of healing is probably mediated by release of secreted cytokines/growth factors, and we hypothesize that the cytokine profile requirement will be modulated as healing progresses. OBJECTIVES: As this is likely to be reflected in lymphocyte subset changes over the course of normal healing, we investigated the immunophenotype of lymphocyte subpopulations during wound healing. METHODS: Sequential biopsies were taken over 42 days from the margin of 12 wounds healing by secondary intention after pilonidal sinus excision. Serial biopsy sections were analysed by immunohistochemistry using lymphocyte-specific monoclonal antibodies, and lymphocytes were counted microscopically. RESULTS: Within 42 days, the mean decrease in wound volume was 87.5%. This was accompanied by significant changes in the wound margin lymphocyte population. Total numbers (mean +/- SEM) of T lymphocytes decreased from 36.8 +/- 9.8 cells per field at inclusion in the study to 25.9 +/- 3.0 immediately prior to wound closure, with a concomitant increase in B lymphocytes from 1 +/- 0.4 to 9.5 +/- 3.6 cells per field. The CD4/CD8 T-lymphocyte ratio fell from an initial level of 3.6 +/- 0.3 to 2.1 +/- 0.3 (mean +/- SEM) prior to closure. CONCLUSIONS: These data indicate that human wound-associated lymphocyte populations are modulated during healing; the increase in numbers of CD8+ T-suppressor lymphocytes is in accordance with previous animal data, indicating a role for these cells in downregulating healing as the wound closes. This study also documents an associated increase in B lymphocytes and healing of human wounds, with an as yet undefined role.

Antibodies, Monoclonal↗
PubMed2000

Enhanced albuminuric response to atrial natriuretic peptide in normoalbuminuric patients with Type 1 diabetes mellitus--a pilot study.

AIMS: To ascertain whether intravenous infusion of atrial natriuretic peptide (ANP) can induce microalbuminuria in patients with Type 1 diabetes mellitus (DM), as already demonstrated in patients with microalbuminuria, and to compare the albuminuric response to ANP infusion in Type 1 DM and a matched group of healthy non-diabetic controls. METHODS: Eight normoalbuminuric DM patients participated in a three limb, randomized, double-blind, placebo-controlled study. Subjects were kept euglycaemic by insulin infusion, and subsequently water-loaded (20 ml/kg orally plus urinary losses). When in steady state, a 30-min infusion of either placebo, ANP 0.025 mg x kg(-1).min(-1) or ANP 0.05 mg x kg(-1) x min(-1) was administered intravenously. Urine was collected every 15 min for 90 min for the estimation of albumin-creatinine ratio (ACR). In addition, eight nondiabetic volunteers received a single infusion of ANP 0.025 mg x kg(-1) x min(-1). RESULTS: ACR was unaltered by placebo in DM subjects (1.4 +/- 0.7-1.7 +/- 1.1 mg/mmol, mean +/- SD, ANOVA, P > 0.9), and by low dose ANP in controls (1.4 +/- 0.9-2.6 +/- 1.9 mg/mmol, P = 0.4). ACR increased with low dose ANP (1.3 +/- 0.5-14.6 +/- 13.6 mg/mmol, P = 0.02), and high dose ANP (1.3 +/- 0.7-26.4 +/- 31 mg/mmol, P = 0.01) in DM subjects. The ACR response to low dose ANP was greater in the DM than control subjects (P = 0.02). CONCLUSIONS: ANP increases urine albumin excretion rate in normoalbuminuric Type 1 DM patients, and this effect is more pronounced than in healthy volunteers.

Adult↗
PubMed2000

A chemiluminescense-based assay for S-nitrosoalbumin and other plasma S-nitrosothiols.

The lack of a simple assay for the quantification of S-nitrosothiols in complex biological matrices has hampered our understanding of their contribution to normal physiology and pathophysiological states. In this paper we describe an assay based upon the release of nitric oxide by reaction with a mixture consisting of Cu(I), iodine and iodide with subsequent quantification by chemiluminescense. With this method we can detect levels of S-nitrosothiols down to 5 nM in plasma. Following alkylation of free thiols with N-ethylmaleimide, and removal of nitrite with acidified sulfanilamide, we were able to measure known amounts of S-nitrosoalbumin added to plasma or whole blood, with an inter-assay variation for plasma S-nitrosothiols of approximately 4%. Further studies showed that the mean concentration of circulating S-nitrosothiols in venous plasma of healthy human volunteers was 28+/-7 nM.

Adult↗
PubMed2000

Crystallization of engineered Thermus flavus 5S rRNA under earth and microgravity conditions.

Thermus flavus 5S rRNA with a molecular weight of about 40 kDa was modified at the 5' and 3' ends. Crystals were obtained under earth and microgravity conditions. The best crystals were obtained during NASA space mission STS 94. For the first time, it was possible to collect a complete data set from 5S rRNA crystals to 7.8 A resolution and to assign the space group as R32, with unit-cell parameters a = b = 110.3, c = 387.6 A, alpha = beta = 90, gamma = 120 degrees.

Base Sequence↗
PubMed2000

Investigating the bacterial barrier properties of four contemporary wound dressings.

The ability of four wound dressings (CombiDERM, Allevyn Hydrocellular, Tegaderm and Tielle) to resist penetration of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis and Pseudomonas aeruginosa was investigated in vitro using a dedicated test apparatus. With the exception of Tielle, each dressing prevented bacterial transmission over an 11-day challenge period. When both the wound contact surface and the external surface of Tielle were directly challenged with a bacterial suspension, penetration of the dressing was observed within three to five days. The breakdown of its outer membrane could explain the inability of Tielle to maintain a barrier to the passage of the test bacteria used in this wound model. On the basis of these data, CombiDERM, Allevyn Hydrocellular and Tegaderm dressings may facilitate infection control by acting as a physical barrier to the transmission of potentially pathogenic and antibiotic-resistant wound bacteria. However, further research is urgently required to determine whether or not the same results are observed in clinical practice.

Bacterial Infections↗
PubMed2000

Causes and effects of the chronic inflammation in venous leg ulcers.

The pathogenesis of venous leg ulcers is multifactorial. In this review article new physiological, molecular and cellular abnormalities in venous ulcers related to the chronic inflammation are presented and discussed. Venous hypertension causes disturbed microcirculation and pathological changes of the capillaries, which eventually locks the condition in a self-amplifying, detrimental cascade with persistent elevated levels and activities of pro-inflammatory cytokines and proteases preventing progress into a healing phase. As a consequence fibroblasts senescence and become less responsive to growth factors the older the ulcers become. Current data imply there is no deficiency but rather an unfavorable distribution of growth factors in venous ulcers. An imbalance in proteolytic enzymes and their endogenous inhibitors is a common finding in chronic venous leg ulcers. Variation in disease severity and concomitant ailments in this heterogeneous patient group may explain the contradictory results in the literature. Thus, to advance the areas of research further, longitudinal studies involving larger number of patients are required to identify the major pathogenic factors.

Chronic Disease↗
PubMed2000

Telemedicine improved diabetic management.

Effective control of diabetes is known to delay or prevent the end-organ complications of this disease. Can telemedicine improve a patient's ability to self-manage diabetes? Twenty-eight patients entered a study comparing home telemedicine consultation with standard outpatient care. A nurse case manager contacted the telemedicine group once a week under the direction of a primary care physician, who contacted the telemedicine group once a month. Laboratory studies and total body weight were measured at the beginning and at the end of the 3-month study. The hemoglobin A1c (HbA1c) and total body weight improved significantly in the intervention (telemedicine) group, as shown by a 16% reduction in mean HbA1c level (from 9.5 to 8.2%) and a 4% mean weight reduction (from 214.3 to 206.7 pounds). Based on our experience, we present a functionally based telemedicine classification system to improve the application of electronic medicine in future studies.

Adult↗
PubMed2000

A multi-state outbreak of tuberculosis among members of a highly mobile social network: implications for tuberculosis elimination.

SETTING: Baltimore, Maryland. OBJECTIVE: To describe a tuberculosis (TB) outbreak among a highly mobile population and the efforts required to control it. DESIGN: Epidemiologic outbreak investigation. RESULTS: Between June 1998 and January 2000, 20 TB outbreak cases were identified, of which 18 were culture-confirmed. Seventeen isolates of Mycobacterium tuberculosis had an identical 11-band DNA fingerprint; another isolate had one additional band and was considered a match. Two cases were diagnosed in New York City; another patient lived primarily in Atlanta, but was diagnosed in Baltimore. Persons in the outbreak were predominantly young (median age 24 years), black, male, infected with the human immunodeficiency virus (HIV), and gay, transvestite or transsexual. Activities common among many TB cases included attending two nightclubs, membership in one of three social 'Houses', attending balls or pageants in East Coast cities, marijuana use, and prostitution. Community outreach, extended contact tracing, DNA fingerprinting, directly-observed therapy, and expanded use of preventive therapy were utilized to assess and control the outbreak. During the outbreak period the Baltimore City TB rate declined by 10%. However, additional public health personnel were required to control the outbreak, resulting in a 17% increase in TB clinic staff. CONCLUSION: As TB rates decline, remaining cases are likely to occur in difficult-to-reach populations. Increased resources per case of TB treated will be required to eliminate TB.

AIDS-Related Opportunistic Infections↗
PubMed1999

Quantification of the major urinary metabolite of 15-F2t-isoprostane (8-iso-PGF2alpha) by a stable isotope dilution mass spectrometric assay.

The isoprostanes (IsoPs) are a series of novel prostaglandin (PG)-like compounds generated from the free radical-catalyzed peroxidation of arachidonic acid. The first series of IsoPs characterized contained F-type prostane rings analogous to PGF2alpha. One F-ring IsoP, 15-F2t-IsoP (8-iso-PGF2alpha) has been shown to be formed in abundance in vivo and to exert potent biological activity. As a means to assess the endogenous production of this compound, we developed a method to quantify the major urinary metabolite of 15-F2t-IsoP, 2,3-dinor-5,6-dihydro-15-F2t-IsoP (2,3-dinor-5, 6-dihydro-8-iso-PGF2alpha), by gas chromotography/negative ion chemical ionization mass spectrometry. This metabolite was chemically synthesized and converted to an 18O2-labeled derivative for use as an internal standard. After purification, the compound was analyzed as a pentafluorobenzyl ester trimethylsilyl ether. Precision of the assay is +/-4% and accuracy is 97%. The lower limit of sensitivity is approximately 20 pg. Levels of the urinary excretion of this metabolite in 10 normal adults were found to be 0. 39 +/- 0.18 ng/mg creatinine (mean +/- 2 SD). Substantial elevations in the urinary excretion of the metabolite were found in situations in which IsoP generation is increased and antioxidants effectively suppressed metabolite excretion. Levels of 2,3-dinor-5, 6-dihydro-15-F2t-IsoP were not affected by cyclooxygenase inhibitors. Thus, this assay provides a sensitive and accurate method to assess endogenous production of 15-F2t-IsoP as a means to explore the pathophysiological role of this compound in human disease.

Adult↗
PubMed1999

Lipoic acid prevents development of the hyperdynamic circulation in anesthetized rats with biliary cirrhosis.

Chronic bile duct ligation is associated with the development of oxidant injury, biliary cirrhosis, portal hypertension, and a hyperdynamic circulation. We have previously demonstrated that the hyperdynamic circulation in the partial portal vein-ligated rat can be prevented by the administration of N-acetylcysteine. To extend these findings, we have examined the effect of lipoic acid, a thiol-containing antioxidant, on hemodynamics, oxidative stress, and nitric oxide (NO) production in bile duct-ligated (BDL) cirrhotic rats. Lipoic acid was given continuously in drinking water to normal and BDL rats; control rats received ordinary drinking water, and animals were studied at 24 days following surgery. Lipoic acid prevented the development of the hyperdynamic circulation (cardiac index [CI]: 15.7 +/- 2.0 vs. 29.5 +/- 2.1 mL x min-1 x 100 g-1; P <. 05) and significantly attenuated the rise in portal pressure (PP) (12.7 +/- 0.8 vs. 15.2 +/- 0.5 mm Hg; P <.05). Hepatic nitric oxide synthase (NOS) activity and plasma nitrite/nitrate concentration increased significantly following bile duct ligation, and both of these were prevented by lipoic acid. Lipoic acid had no effect on the biochemical or histological parameters of liver function in the cirrhotic group. We conclude that lipoic acid prevents the development of the hyperdynamic circulation in the rat model of biliary cirrhosis, and that this is associated with decreased synthesis of NO.

Animals↗