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M R Jackson

Publications and source records attributed to M R Jackson.

At least 37 records · Page 2Linked to original sources
PubMed1999

TCR-Mediated internalization of peptide-MHC complexes acquired by T cells.

Peptide-major histocompatibility complex protein complexes (pMHCs) on antigen-presenting cells (APCs) are central to T cell activation. Within minutes of peptide-specific T cells interacting with APCs, pMHCs on APCs formed clusters at the site of T cell contact. Thereafter, these clusters were acquired by T cells and internalized through T cell receptor-mediated endocytosis. During this process, T cells became sensitive to peptide-specific lysis by neighboring T cells (fratricide). This form of immunoregulation could explain the "exhaustion" of T cell responses that is induced by high viral loads and may serve to down-regulate immune responses.

Animals↗
PubMed1999

The pharmacological and functional characteristics of the serotonin 5-HT(3A) receptor are specifically modified by a 5-HT(3B) receptor subunit.

While homomers containing 5-HT(3A) subunits form functional ligand-gated serotonin (5-HT) receptors in heterologous expression systems (Jackson, M. B., and Yakel, J. L. (1995) Annu. Rev. Physiol. 57, 447-468; Lambert, J. J., Peters, J. A., and Hope, A. G. (1995) in Ligand-Voltage-Gated Ion Channels (North, R., ed) pp. 177-211, CRC Press, Inc., Boca Raton, FL), it has been proposed that native receptors may exist as heteromers (Fletcher, S., and Barnes, N. M. (1998) Trends Pharmacol. Sci. 19, 212-215). We report the cloning of a subunit 5-HT(3B) with approximately 44% amino acid identity to 5-HT(3A) that specifically modified 5-HT(3A) receptor kinetics, voltage dependence, and pharmacology. Co-expression of 5-HT(3B) with 5-HT(3A) modified the duration of 5-HT(3) receptor agonist-induced responses, linearized the current-voltage relationship, increased agonist and antagonist affinity, and reduced cooperativity between subunits. Reverse transcriptase-polymerase chain reaction in situ hybridization revealed co-localization of both 5-HT(3B) and 5-HT(3A) in a population of neurons in the amygdala, telencephalon, and entorhinal cortex. Furthermore, 5-HT(3A) and 5-HT(3B) mRNAs were expressed in spleen and intestine. Our data suggest that 5-HT(3B) might contribute to tissue-specific functional changes in 5-HT(3)-mediated signaling and/or modulation.

Amygdala↗
PubMed1999

Transferrin receptor is negatively modulated by the hemochromatosis protein HFE: implications for cellular iron homeostasis.

Hereditary hemochromatosis is a common autosomal recessive disorder of iron metabolism. Recent demonstration of an association between transferrin receptor (TfR) and HFE, a major histocompatibility complex class I-like molecule that has been implicated to play a role in hereditary hemochromatosis, further strengthens the notion that HFE is involved in iron metabolism. Herein we show that TfR is required for and controls the assembly and the intracellular transport and surface expression of HFE. Because surface-expressed HFE and TfR remain firmly associated physically, only the fraction of TfR that is associated with HFE during biosynthesis is affected functionally. Moreover, we show that HFE binding reduces the number of functional transferrin binding sites and impairs TfR internalization, thus reducing the uptake of transferrin-bound iron. Thus, iron homeostasis is indirectly regulated by HFE, a negative modulator of TfR.

Amino Acid Sequence↗
PubMed1999

Intercellular adhesion molecule-1 inhibits interleukin 4 production by naive T cells.

The type of cytokines produced during T cell responses determines susceptibility or resistance to many pathogens and influences the development of autoimmunity and allergy. To define the role of individual accessory molecules in cytokine production during primary immune responses, Drosophila cell lines expressing murine major histocompatibility complex class II molecules with defined combinations of accessory molecules were used to present peptide antigen to naive T cell receptor transgenic T cells. Significantly, expression of B7.1 or B7.2 without additional accessory molecules led to very high production of interleukin (IL)-4, which contrasted with minimal IL-4 production elicited by conventional antigen presenting cells (APC). However, coexpression of ICAM-1 and B7 on Drosophila APC induced little IL-4, suggesting an inhibitory role for intercellular adhesion molecule-1 (ICAM-1). In support of this idea, stimulation of T cell receptor transgenic T cells with peptide presented by splenic APC devoid of ICAM-1 (from ICAM-1-deficient mice) led to high IL-4 production. Thus, the level of IL-4 production by naive CD4(+) T cells during typical primary responses appears to be controlled, at least in part, by T-APC interactions involving ICAM-1.

Animals↗
PubMed1999

Complex aortofemoral prosthetic infections: the role of autogenous superficial femoropopliteal vein reconstruction.

BACKGROUND: With increasing experience, we have encountered patients with complex aortofemoral prosthetic infections in whom extra-anatomic bypass (EAB) is not an option. HYPOTHESIS: Autogenous superficial femoropopliteal vein (SFPV) aortic reconstruction provides a limb-saving and lifesaving alternative with acceptable morbidity and mortality. DESIGN: Retrospective review. SETTING: University-based county, private, and Veterans Affairs hospitals. PATIENTS: Seventeen patients with infected aortofemoral bypasses in whom conventional EAB was impossible because of infection of previously placed EAB, massive groin and/or thigh sepsis, or both. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: Multiple previous operations were common (mean, 4 per patient) and included EAB (n = 11), replacement aortofemoral bypass (n = 4), prosthetic femoropopliteal bypass (n = 7), and thoracobifemoral bypass (n = 1); all bypasses became infected. Overall, 11 patients had sepsis at the time of presentation. Of the patients with massive groin infection, 7 had extensive deep infections involving most of the proximal thighs or retroperitoneum, 4 had enterocutaneous fistulae, and 2 had necrotizing fasciitis of the lower abdomen and thigh. Polymicrobial infections were common (n = 9). Four patients (24%) died in the perioperative period, 8 (47%) suffered major complications, and 4 (24%) underwent major amputations. Mortality in this group of patients was 3 times that of all other patients undergoing autogenous SFPV aortic reconstruction for prosthetic infection (8%). Amputation rates were also increased (24% vs 6%). The mean+/-SD follow-up time is 23+/-21 months. All patients maintained patent SFPV reconstructions. CONCLUSIONS: In the setting of complex aortofemoral prosthetic infections, autogenous SFPV aortic reconstruction is a useful option for patients in whom EAB is impossible and limb loss and/or death would be inevitable without revascularization.

Adult↗
PubMed1999

Adoptive immunotherapy prevents prostate cancer in a transgenic animal model.

Cancer-related mortality can be decreased by prevention, early detection and improved therapies. Although animal models should be used to evaluate the success of cancer therapies, their usefulness is controversial. Many cancer therapies that have cured tumors in mice have not met with similar success when attempted in humans. Current animal models rely mainly on inoculating cell lines into animals, a method that does not reproduce the natural development of the tumor, both for the kinetics of induction and the anatomical site concerned. In this study, we have used an SV40 T-antigen-transgenic mouse model of prostate cancer in which the tumor spontaneously develops orthotopically with a disease progression that closely resembles the progression of human prostate cancer. We have used this model to test the suitability of adoptive cellular immunotherapy. Transfer of naive cells obtained from a T-antigen-negative congenic animal had significant but partial effects: it prevented development of malignant tumors, leaving just minor foci of residual tumor and/or hyperplasia. Adoptive transfer of memory lymphocytes specific for T-antigen, which is a prostatic self antigen in this model, prevented tumor development and progression without affecting the morphology and function of involved tissues. Treated animals were able to breed, and their survival was greatly increased. These results strongly suggest that adoptive immunotherapy should be successful in treating early stages of human prostate cancer.

Adenocarcinoma↗
PubMed1999

The progressive nature of peripheral arterial disease in young adults: a prospective analysis of white men referred to a vascular surgery service.

OBJECTIVE: The onset of symptomatic peripheral arterial disease at a young age (premature PAD) has been associated with rapid progression, bypass graft failure, and amputation. This study was performed to document the incidence of these complications and to determine the risk factors for poor outcome in patients with premature PAD. METHODS: This study was designed as a prospective longitudinal analysis, with patients who were ambulatory or hospitalized at a single vascular referral institution. The subjects were 51 white men with onset of PAD symptoms before the age of 45 years (mean age of onset, 41 +/- 0.5 years) and represented consecutive patients who were seen at the vascular surgery service during a 4-year period. Thirty of the study subjects (58%) were recruited during the first 2 years. The main outcome measures were number and type of lower extremity revascularization procedures or amputations that were necessitated during the follow-up period. RESULTS: During a mean follow-up period of 73 +/- 6 months, 15 patients (29%) had PAD that remained stable without interventions and 15 (29%) had PAD that remained stable for a mean of 76 +/- 13 months after a single intervention. Twenty-one patients (41%) required multiple operations or major amputations. In a comparison of the 30 PAD patients whose conditions were stable with or without a single intervention with the 21 PAD patients who required multiple interventions (REDO), there were no differences in smoking, hypertension, diabetes, or dyslipidemias. The REDO group had a younger mean age at the onset of symptoms (39 +/- 1 years vs 43 +/- 2 years; P <.001). At entry, the REDO patients had a higher prevalence of infrainguinal or multilevel disease (57% vs 20%; P =.03), a lower mean ankle brachial index (0. 44 +/- 0.04 vs 0.56 +/- 0.03; P =.02), and more frequent tissue loss (24% vs 0; P =.005). The REDO patients had a higher mean lipoprotein (a) level than did the patients with stable conditions (51 +/- 11 mg/dL vs 27 +/- 5 mg/dL; P =.03), but there were no significant differences in the mean plasma homocysteine levels (19 +/- 2 micromol/L vs 16 +/- 1 micromol/L) or in the proportion of patients with hypercoagulable states (33% vs 30%). The only predictive variables that were selected with stepwise logistic regression analysis were age at onset (P <.002; odds ratio, 1.4; 95% confidence interval, 1.11 to 1.81) and ankle brachial index of less than 0.5 (P <.008; odds ratio, 6.4; 95% confidence interval, 1.5 to 27.3). CONCLUSION: Although 60% of the white men with premature PAD who were referred to a vascular surgery service had conditions that appeared to remain stable, these data show that approximately 40% of the patients will require multiple interventions because of disease progression or bypass graft failure. Clinical indicators, not serum markers, are predictors of poor outcome in patients with premature PAD. The results of this study suggest that patients with onset of PAD before the age of 43 years who have objective evidence of advanced disease are predisposed to multiple interventions.

Adult↗
PubMed1999

Hemostatic efficacy of fibrin sealant (human) on expanded poly-tetrafluoroethylene carotid patch angioplasty: a randomized clinical trial.

PURPOSE: The efficacy of solvent-detergent-treated fibrin sealant (human [FSH]) for controlling anastomotic bleeding from expanded polytetrafluoroethylene (ePTFE) patch angioplasty during carotid endarterectomy was evaluated, and FSH was compared with thrombin-soaked gelatin sponge (Gelfoam; TSG). METHODS: The study was of a randomized, open-label, single-site, single-treatment, parallel design that took place in a referral center with hospitalized patients. Forty-seven adult patients (33 men, 14 women) underwent elective carotid endarterectomy. Patients were randomized to receive either FSH (N = 24) or TSG (N = 23). FSH was obtained as an investigational new drug. FSH was applied as a liquid by means of a dual-syringe technique. Heparin anticoagulation, patch thickness, and suture type were standardized. Two different needle sizes were used (CV-6, PT-13: N = 21 [FSH: N = 10, TSG: N = 11]; CV-6, PT-9: N = 26 [FSH: N = 14, TSG: N = 13]). The FSH or TSG was applied to the ePTFE patch, and then blood flow was restored through the carotid artery. Degree of anticoagulation was assessed by anti-factor Xa activity. The time from restoration of carotid blood flow until achieving hemostasis was recorded. The blood loss from patch suture hole bleeding was measured. Completion intraoperative duplex ultrasound scanning was performed in all cases. Heparin was reversed with protamine sulfate. The primary end point was successful hemostasis within 15 minutes of restoration of carotid blood flow. The secondary end points were the amount of blood loss caused by suture line bleeding and the time to achieve hemostasis. RESULTS: There was no difference in the number of patients with complete hemostasis at 15 minutes (TSG, 13 of 23; FSH, 12 of 24; P =.77). The measured blood loss was 99.0 +/- 119.9 (SD) mL for TSG, and 105.0 +/- 107.9 mL for FSH (P =.86). The time to hemostasis was the same for both groups (TSG, 16.5 +/- 16.5 minutes; FSH, 16.6 +/- 14.2 minutes; P =.97). Within both treatment groups, the use of larger needles (PT-13) was associated with greater blood loss (FSH, 169.7 +/- 124.2 mL; TSG, 172.7 +/- 151.5 mL) than was the use of smaller needles (PT-9; FSH, 58.8 +/- 66.3 mL; TSG, 34.1 +/- 25.6 mL; P =.036, P =.001, respectively). There were no postoperative strokes or bleeding complications in either group. No abnormalities were shown in either group by means of completion carotid duplex ultrasound scanning. CONCLUSION: FSH was equivalent, but not superior to, TSG in achieving hemostasis during carotid endarterectomy performed with ePTFE patch angioplasty. Adhesion properties of FSH to ePTFE are possibly different than those to native tissue and warrant additional investigation.

Adult↗
PubMed1999

A randomized trial of intraoperative autotransfusion during aortic surgery.

PURPOSE: The net benefit of routine intraoperative autotransfusion (IAT) in patients undergoing elective infrarenal aortic surgery was studied. METHODS: One hundred patients undergoing abdominal aortic aneurysm (AAA) repair (n = 50) or aortofemoral bypass (AFB) for occlusive disease (n = 50) were randomized to IAT and control groups. This experience accounted for 58% of patients undergoing aortic surgery during the 16-month study period. RESULTS: IAT and control groups were balanced for preoperative demographics, disease (50:50 split of AFB:AAA in each group), and risk factors. There were no significant differences between patients randomized to IAT and control patients in estimated blood loss (EBL), allogeneic blood transfusion (units administered intraoperatively, postoperatively, and total), proportion of patients not receiving allogeneic blood (34% of patients randomized to IAT and 28% of control patients), postoperative hemoglobin/hematocrit levels, and complications. IAT did not reduce allogeneic blood transfusion among all patients undergoing aortic surgery nor in any subgroups that might be more likely to benefit, such as those undergoing AAA repair, those with 1000 mL or more EBL, and those receiving larger volumes of IAT-processed blood. CONCLUSION: We could find no net benefit of IAT in patients undergoing elective, infrarenal aortic surgery.

Aged↗
PubMed1999

Venous morbidity after superficial femoral-popliteal vein harvest.

PURPOSE: The superficial femoral-popliteal vein (SFPV) is a reliable conduit for aortoiliac, infrainguinal, and venous reconstructions. In this prospective study, we characterized the anatomic and physiologic changes in SFPV harvest limbs and their relationship to the development of late venous complications. METHODS: Since 1990, we have studied 61 patients after harvest of 86 SFPVs at 6-month intervals with clinical examinations, lower-extremity venous duplex, and venous function tests. The CEAP system was used as a means of categorizing clinical changes. RESULTS: Mean (+/- SEM) follow-up was 37 +/- 3 months. Less than one third of harvest limbs had edema without skin changes (C3). No patient had major chronic venous changes (C4 to C6) or venous claudication. There were no significant differences in limb measurements between harvest and non-harvest limbs, except in a subgroup of patients with unilateral harvest in which there was a small but significant (P =.046) increase in harvest limb thigh and calf circumference, compared with the opposite non-harvest limb. These clinical results were not affected by the presence or absence of an intact greater saphenous vein (GSV). Large, direct collaterals (4 to 6 mm in diameter) between the popliteal vein stump and profunda femoris vein (PFV) were seen by means of duplex ultrasonography in 29 harvest limbs (34%). The remainder appeared to have smaller, less direct collaterals to the PFV. Mild venous reflux with rapid cuff deflation was present at the popliteal or posterior tibial vein in nine of 79 harvest limbs (11%). Six of these nine limbs (67%) with reflux were clinical class C3, compared with only 19 of the 70 limbs without reflux (27%; P =.02). Ambulatory venous pressure (AVP) with exercise was significantly increased in harvest limbs (60 +/- 4.7 mm Hg), compared with non-harvest limbs (47.8 +/- 5.2 mm Hg; P =.049). The AVP recovery time of harvest limbs (14.0 +/- 1.0 seconds) was reduced, compared with non-harvest limbs (23.5 +/- 4.5 seconds; P =.02). AVPs (exercise) remained stable or decreased in six of 10 harvest limbs measured serially. Venous refill time in harvest limbs (15.1 +/- 1.1 seconds) was shortened, compared with non-harvest limbs (22.3 +/- 2. 1 seconds)(P =.002). Venous outflow obstruction measured by means of plethysmography was present in 93% of harvest limbs, compared with 36% of non-harvest limbs (P =.001). CONCLUSION: SFPV harvest results in minimal mid-term to late-term lower-extremity venous morbidity despite outflow obstruction. The most likely mechanisms preserving clinical status include the low incidence of mild reflux, the presence of collateral venous channels, and the lack of progression in abnormal harvest limb physiology. The absence of the ipsilateral GSV does not adversely affect clinical outcome.

Adolescent↗
PubMed1999

Fibrin sealant in preclinical and clinical studies.

Fibrin sealant, now commercially available in the United States, is a virally inactivated preparation of highly purified human fibrinogen and human thrombin that includes aprotinin to reduce fibrinolysis. Although the product is relatively expensive, cost can be justified when the sealant is used to produce localized hemostasis in surgery in which bleeding cannot be controlled by sutures. Fibrin sealant can also be justified as an alternative to factor concentrates in patients with coagulopathies who have a localized site of bleeding. Newer formulations of fibrinogen and thrombin in a freeze-dried form applied as a bandage may be useful in immediate, on-site treatment of trauma victims in either a civilian or military setting.

Animals↗
PubMed1999

DNA microarrays of the complex human cytomegalovirus genome: profiling kinetic class with drug sensitivity of viral gene expression.

We describe, for the first time, the generation of a viral DNA chip for simultaneous expression measurements of nearly all known open reading frames (ORFs) in the largest member of the herpesvirus family, human cytomegalovirus (HCMV). In this study, an HCMV chip was fabricated and used to characterize the temporal class of viral gene expression. The viral chip is composed of microarrays of viral DNA prepared by robotic deposition of oligonucleotides on glass for ORFs in the HCMV genome. Viral gene expression was monitored by hybridization to the oligonucleotide microarrays with fluorescently labelled cDNAs prepared from mock-infected or infected human foreskin fibroblast cells. By using cycloheximide and ganciclovir to block de novo viral protein synthesis and viral DNA replication, respectively, the kinetic classes of array elements were classified. The expression profiles of known ORFs and many previously uncharacterized ORFs provided a temporal map of immediate-early (alpha), early (beta), early-late (gamma1), and late (gamma2) genes in the entire genome of HCMV. Sequence compositional analysis of the 5' noncoding DNA sequences of the temporal classes, performed by using algorithms that automatically search for defined and recurring motifs in unaligned sequences, indicated the presence of potential regulatory motifs for beta, gamma1, and gamma2 genes. In summary, these fabricated microarrays of viral DNA allow rapid and parallel analysis of gene expression at the whole viral genome level. The viral chip approach coupled with global biochemical and genetic strategies should greatly speed the functional analysis of established as well as newly discovered large viral genomes.

Base Sequence↗
PubMed1999

Physiologic responses of cross-linked hemoglobin in endotoxin-treated rats.

Purified human cross-linked hemoglobin (alpha alpha Hb) as well as recombinant human hemoglobin is undergoing clinical trials in the setting of acute blood loss and perioperative hemodilution. We have previously demonstrated that in rabbits with circulating plasma Hb, such as alpha alpha Hb, infusion of endotoxin (LPS) impairs myocardial contractility which results in hypotension, tissue hypoperfusion and increased mortality. The untoward cardiovascular effects occurring after the combined infusion of LPS and alpha alpha Hb in this model are similar to those reported for other agents that inhibit nitric oxide (NO) availability. To determine if the deleterious effects of alpha alpha Hb and LPS were species specific, we performed similar studies in rats. Anesthetized Sprague-Dawley rats received LPS (4 mg/kg or 40 mg/kg) alone or in combination with alpha alpha Hb (0.7 g/kg). Mean arterial blood pressures (MAP) increased in the group that received alpha alpha Hb alone (105 +/- 8 to 120 +/- 7 mm Hg, p = 0.2) and a decrease was noted in the groups that received low dose LPS (4 mg/kg, p = 0.5) and high dose LPS (40 mg/kg, p = 0.016). MAP in rats treated with the LPS at either dose combined with alpha alpha Hb remained unchanged. Levels of urine nitrite, which was measured as a surrogate marker for plasma NO, were significantly decreased at 2 hr in groups that received the combination of alpha alpha Hb and LPS at 4 mg/kg (p = 0.022) and 40 mg/kg (p = 0.003). No significant decrease was observed in animals treated only with alpha alpha Hb (p = 0.21) or LPS (4 mg/kg; p = 0.78 and 40 mg/kg; p = 0.65). Survival was evaluated during 72 hr in animals that were infused with high dose LPS (40 mg/kg) alone or in combination with alpha alpha Hb and then allowed to recover. The survival of rats treated with LPS alone or the combination was 29% at the end of 24 hr and was 100% for rats receiving only alpha alpha Hb. The data suggest that the toxicity of alpha alpha Hb appears to be a species specific phenomenon.

Anesthesia↗
PubMed1999

Cloning and functional expression of the human histamine H3 receptor.

Histamine regulates neurotransmitter release in the central and peripheral nervous systems through H3 presynaptic receptors. The existence of the histamine H3 receptor was demonstrated pharmacologically 15 years ago, yet despite intensive efforts, its molecular identity has remained elusive. As part of a directed effort to discover novel G protein-coupled receptors through homology searching of expressed sequence tag databases, we identified a partial clone (GPCR97) that had significant homology to biogenic amine receptors. The GPCR97 clone was used to probe a human thalamus library, which resulted in the isolation of a full-length clone encoding a putative G protein-coupled receptor. Homology analysis showed the highest similarity to M2 muscarinic acetylcholine receptors and overall low homology to all other biogenic amine receptors. Transfection of GPCR97 into a variety of cell lines conferred an ability to inhibit forskolin-stimulated cAMP formation in response to histamine, but not to acetylcholine or any other biogenic amine. Subsequent analysis revealed a pharmacological profile practically indistinguishable from that for the histamine H3 receptor. In situ hybridization in rat brain revealed high levels of mRNA in all neuronal systems (such as the cerebral cortex, the thalamus, and the caudate nucleus) previously associated with H3 receptor function. Its widespread and abundant neuronal expression in the brain highlights the significance of histamine as a general neurotransmitter modulator. The availability of the human H3 receptor cDNA should greatly aid in the development of chemical and biological reagents, allowing a greater appreciation of the role of histamine in brain function.

Adenylyl Cyclase Inhibitors↗
PubMed1998

Requirements for stimulating naive CD8+ T cells via signal 1 alone.

In the absence of costimulation, TCR recognition of peptide/MHC complexes is generally considered to be nonimmunogenic. In agreement with this view, naive TCR transgenic CD8+ cells failed to respond to specific peptides presented by MHC class I (Ld) molecules bound to mouse RBC. However, peptide/Ld complexes presented by cell-sized beads or bound to plastic led to overt proliferative responses in the absence of added cytokines. Significantly, equivalent strong proliferative responses occurred when mouse RBC were fixed with glutaraldehyde before Ld coupling. The implication therefore is that the intensity of signaling via the TCR is a reflection of the mobility of the ligand being recognized; TCR signaling is weak when the ligand can move laterally on the cell membrane but strong when the ligand is immobilized.

Animals↗
PubMed1998

Rab2 protein enhances coatomer recruitment to pre-Golgi intermediates.

The Rab2 protein is a resident of pre-Golgi intermediates and required for vesicular transport in the early secretory pathway. We have previously shown that a peptide corresponding to the amino terminus of Rab2 (residues 2-14) arrests protein traffic prior to a rate-limiting event in VSV-G movement through pre-Golgi structures (Tisdale, E. J., and Balch, W. E. (1996) J. Biol. Chem. 271, 29372-29379). To determine the mechanism by which this peptide inhibits transport, we investigated the effect of the Rab2 peptide on the distribution of the beta-COP subunit of coatomer because COPI partially localizes to pre-Golgi intermediates. We found that the peptide caused a dramatic change in the distribution of pre-Golgi intermediates containing beta-COP. A quantitative binding assay was employed to measure recruitment of beta-COP to membrane when incubated with the Rab2 (13-mer). Peptide-treated microsomes showed a 25-70% increase in the level of membrane-associated beta-COP. The enhanced recruitment of coatomer to membrane was specific to the Rab2 (13-mer) and required guanosine 5'-3-O-(thio)triphosphate, ADP ribosylation factor, and protein kinase C-like activity. The ability to enhance beta-COP membrane binding was not limited to the peptide. Similarly, the addition of recombinant Rab2 protein to the assay promoted beta-COP membrane association. Our results suggest that the Rab2 peptide causes the persistent recruitment of COPI to pre-Golgi intermediates which ultimately arrests protein transport due to the inability of membranes to uncoat.

Amino Acid Sequence↗
PubMed1998

Priorities in the development of alternative methodologies in the pharmaceutical industry.

Promotion of animal welfare is an underlying and laudable goal for toxicologists and there is good reason to adopt practical, focused, investigative approaches towards this aim. Pharmaceutical regulatory toxicology can be subdivided into the areas of systemic (target organ), reproductive, genetic and topical toxicology, as well as immunotoxicology and oncology. These areas can be assessed for prioritisation as to where adoption of measures to promote any or all of the 3 Rs (reduction, replacement, refinement) would lead to the most tangible benefit for animals. These measures can range, for example, from replacement of animal experimentation with alternative in vitro techniques, to adoption of regulatory protocols that reduce the number of animals required. This paper is confined to consideration of in vitro technology in terms of reducing/replacing laboratory animal use, and a suggested list of criteria for prioritisation is potential for:- Regulatory acceptability Reducing development cost Reducing animal numbers Promoting welfare aspects Elucidating toxic mechanisms Usefulness in compound selection Advancing the science of toxicology Clear messages emerge from such an analysis which could influence prioritisation of the application of in vitro toxicology from the standpoints of animal welfare, feasibility and resources.

Animal Testing Alternatives↗