Biomedical subjects

R H Moore

Publications and source records attributed to R H Moore.

At least 19 recordsLinked to original sources

PubMed2004

Computerized detection of mass lesions in digital breast tomosynthesis images using two- and three dimensional radial gradient index segmentation.

Initial results for a computerized mass lesion detection scheme for digital breast tomosynthesis (DBT) images are presented. The algorithm uses a radial gradient index feature for the initial lesion detection and for segmentation of lesion candidates. A set of features is extracted for each segmented partition. Performance of two- and three dimensional features was compared. For gradient features, the additional dimension provided no improvement in classification performance. For shape features, classification using 3D features was improved compared to the 2D equivalent features. The preliminary overall performance was 76% sensitivity at 11 false positives per exam, estimated based on DBT image data of 21 masses. A larger database will allow for further development and improvement in our computer aided detection scheme.

Breast Neoplasms↗

PubMed2001

Lysosome proteins are redistributed during expression of a GTP-hydrolysis-defective rab5a.

The functioning of the endocytic pathway is influenced by a distinct set of rab GTPases, including rab5a, which regulates homotypic fusion of early endosomes. Expression of a dominant active, GTPase-defective rab5a accelerates endosome fusion, causing the formation of a greatly enlarged endocytic compartment. Here we present evidence that rab5a also regulates trafficking between endosomes and lysosomes and may play a role in lysosome biogenesis. The GTPase defective rab5aQ79L mutant was inducibly expressed as an EGFP fusion in HEK293 cells, and the distribution of lysosome proteins and endocytic markers then assessed by deconvolution fluorescence microscopy. During expression of EGFP-rab5aQ79L, the lysosome proteins LAMP-1, LAMP-2 and cathepsin D were found in dilated EGFP-rab5aQ79L-positive vesicles, which also rapidly labeled with transferrin Texas Red. Exogenous tracers that normally traffic to lysosomes after prolonged chase (dextran Texas Red and DiI-LDL) also accumulated in these vesicles. Dextran Texas Red preloaded into lysosomes localized with subsequently expressed EGFP-rab5a Q79L, suggesting the existence of lysosome to endosome traffic. Cells expressing EGFP-rab5a wt or the dominant negative EGFP-rab5aS34N did not exhibit these abnormalities. Despite the dramatic alterations in lysosome protein distribution caused by expression of EGFP-rab5a Q79L, there was little change in the endocytosis or recycling of a cell-surface receptor (beta2-adrenergic receptor). However, there was a deficiency of dense beta-hexosaminidase-containing lysosomes in cells expressing EGFP-rab5aQ79L, as assessed by Percoll gradient fractionation. These results suggest that expression of a GTPase-defective rab5a affects lysosome biogenesis by alteration of traffic between lysosomes and endosomes.

Cell Line↗

PubMed2000

Localization of the sites mediating desensitization of the beta(2)-adrenergic receptor by the GRK pathway.

The human beta(2)-adrenergic receptor (betaAR) is rapidly desensitized in response to saturating concentrations of agonist by G protein-coupled receptor kinases (GRKs) and cAMP-dependent protein kinase A (PKA) phosphorylation of the betaAR, followed by beta-arrestin binding and receptor internalization. betaAR sites phosphorylated by GRK in vivo have not yet been identified. In this study, we examined the role of the carboxyl terminal serines, 355, 356, and 364, in the GRK-mediated desensitization of the betaAR. Substitution mutants of these serine residues were constructed in which either all three (S355,356,364A), two (S355,356A and S356, 364A), or one of the serines (S356A and S364A) were modified. These mutants were constructed in a betaAR in which the serines of the PKA consensus site were substituted with alanines (designated PKA(-)) to eliminate any PKA contribution to desensitization, and they were stably transfected into human embryonic kidney 293 cells. Treatment of the PKA(-) mutant with 10 microM epinephrine for 5 min caused a 3. 5-fold increase in the EC(50) value and a 42% decrease in the V(max) value for epinephrine stimulation of adenylyl cyclase. Substitution of all three serines completely inhibited the epinephrine-induced shift in the EC(50). Both double mutants, S355,356A and S356,364A, showed a nearly complete loss of the EC(50) shift, whereas the single substitutions, S356A and S364A, caused only a slight decrease in desensitization. None of the mutations altered the epinephrine-induced decrease in V(max,) which seems to be downstream of the receptor. The triple mutation caused a 45% decrease in epinephrine-induced internalization and a 90 to 95% reduction in phosphorylation of the betaAR relative to the PKA(-) (1.9+/- 0.2- and 16.6+/-3.8-fold phosphorylation over basal, respectively). The double mutants caused an intermediate reduction in internalization (20-21%) and phosphorylation (43-52%). None of the serine mutations altered the rate of betaAR recycling. Our data demonstrate that the cluster of serines within the 355 to 364 betaAR domain confer the rapid, GRK-mediated, receptor-level desensitization of the betaAR.

Adenylyl Cyclases↗

PubMed1999

Comparison of microemulsion and conventional formulations of cyclosporine A in preventing acute rejection in de novo kidney transplant patients. The U.K. Neoral Renal Study Group.

BACKGROUND: The microemulsion preconcentrate formulation of cyclosporine A (CsA) (Neoral) exhibits more uniform pharmacokinetics than the conventional formulation (Sandimmun; SIM). This randomized, open-label, U.K. multicenter study compared the efficacy, safety, and tolerability of Neoral and SIM in preventing acute rejection in de novo renal transplant recipients. METHODS: Adult cadaveric kidney recipients (n=293) received Neoral or SIM twice daily for 12 months. Initially identical Neoral and SIM doses were titrated, maintaining trough CsA levels within locally defined therapeutic limits. RESULTS: In the year after transplantation, acute rejection occurred in 34% of the Neoral and 47% of the SIM recipients (P=0.037). In the intent-to-treat population, fewer treatment failures (defined as acute rejection, graft loss, withdrawal, or death) occurred in the Neoral (45%) than the SIM recipients (58%) (P=0.015) and therapeutic CsA levels (> or =250 microg/L) were reached faster with Neoral than SIM (P=0.0017). Antibody treatment of refractory rejection was used slightly less in the Neoral group (Neoral: 10%; SIM: 12%). One-year patient and graft survival rates (excluding deaths with functioning grafts) were 95% and 88%, respectively, for Neoral and 96% and 89% for SIM. Both formulations were well tolerated. No differences were observed between therapies in the nature, frequency, or severity of adverse events. Neoral use was not associated with increased nephrotoxicity or excessive immunosuppression. CONCLUSIONS: Neoral reduced the incidence of acute rejection compared with SIM, without significant increases in adverse events. This was achieved without altering existing SIM protocols and was attributed to improved absorption of CsA from Neoral and less variability in whole blood CsA concentrations.

Acute Disease↗

PubMed1999

Specific changes in beta2-adrenoceptor trafficking kinetics and intracellular sorting during downregulation.

Agonist-activated beta2-adrenoceptors rapidly internalize and then recycle to the cell surface, however chronic agonist eventually causes receptor downregulation. To characterize beta2-adrenoceptor trafficking kinetics and intracellular sorting during downregulation, human embryonic kidney cells expressing epitope-tagged receptors were examined by radioligand binding with (+/-)-[3H]4-(3-tertiarybutylamino-2-hydroxypropoxy)-benzimidazole- 2-on hydrochloride ([3H]CGP12177) and immunofluorescence microscopy. The first-order receptor recycling rate constant declined after 18 h of agonist compared with 15 min (0.05 min(-1) vs. 0.12 min(-1)), thus increasing the intracellular transit time (20.0 min vs. 8.3 min). There was also a reduction in the rate of receptor endocytosis and a decline in the total number of receptors. Although the intracellular receptor fraction did not increase between 15 min and 18 h of agonist, some receptors moved irreversibly into a protease-containing compartment while retaining radioligand binding activity. Our results indicate that beta2-adrenoceptor downregulation is associated principally with an increased intracellular transit time during recycling. This could promote the diversion of receptors into protease-containing compartments, where there is an irreversible commitment to downregulation prior to loss of radioligand binding activity.

Adrenergic beta-Agonists↗

PubMed1999

Rab3D, a small GTPase, is localized on mast cell secretory granules and translocates to the plasma membrane upon exocytosis.

Although mast cell secretion has been intensively studied because of its pivotal role in allergic reactions and its advantages as a physiologic model, the molecular composition of the secretory machine is virtually unknown. In view of the guanine-nucleotide dependency of mast cell exocytosis and the participation of Rab3 proteins in synaptic vesicle release, we hypothesized that a Rab3 isoform regulates mast cell secretion. Fragments of Rab3A, 3B, and 3D were cloned from RBL-2H3 mast cells by reverse transcription- polymerase chain reaction (RT-PCR). Northern blot analysis revealed Rab3D transcripts to be relatively abundant, Rab3B substantially less so, and Rab3A and 3C undetectable. By ribonuclease (RNase) protection assay, Rab3D transcripts were at least 10-fold more abundant than those of other isoforms, and by immunoblot analysis, Rab3D protein was at least 60-fold more abundant than that of Rab3B. Rab3D was more abundant in RBL cells than in brain, but the total mass of Rab3 proteins in RBL cells was 10-fold less than in brain. Rab3D only partly colocalized with secretory granules in RBL cells, but fully colocalized in mature peritoneal mast cells. There was a descending concentration gradient of Rab3D from peripheral to central granules, and no cytoplasmic pool was detectable in resting mast cells. Following exocytotic degranulation, Rab3D translocated to the plasma membrane and remained there for at least 15 min. These studies suggest that Rab3D is a component of the regulated exocytotic machine of mast cells, and identify differences between mast cells and neurons in Rab3 expression and trafficking.

Amino Acid Sequence↗

PubMed1999

Agonist-induced sorting of human beta2-adrenergic receptors to lysosomes during downregulation.

During prolonged exposure to agonist, beta2-adrenergic receptors undergo downregulation, defined by the loss of radioligand binding sites. To determine the cellular basis for beta2-adrenergic receptor downregulation, we examined HEK293 cells stably expressing beta2-adrenergic receptors with an N-terminal epitope tag. Downregulation was blocked by leupeptin, a cysteine protease inhibitor, but not by pepstatin, an inhibitor of aspartate proteases. Immunofluorescence microscopy of cells treated with agonist for 3-6 hours in the presence of leupeptin showed beta2-adrenergic receptors, but not transferrin receptors, localizing with the lysosomal protease cathepsin D, and with lysosomes labeled by uptake of a fluorescent fluid-phase marker. No localization of beta2-adrenergic receptors with lysosomal markers was observed in the absence of leupeptin, most likely due to proteolysis of the epitope. The proton pump inhibitor, bafilomycin A1, significantly inhibited this agonist-induced redistribution of beta2-adrenergic receptors into lysosomes, causing receptors to accumulate in the rab11-positive perinuclear recycling compartment and slowing the rate of beta2-adrenergic receptor recycling. Control experiments showed that leupeptin had no nonspecific effects on the cellular trafficking of either beta2-adrenergic receptors or transferrin receptors. Although cAMP alone caused a small decline in receptor levels without redistributing beta2-adrenergic receptors from the plasma membrane, this effect was additive to that seen with agonist alone, suggesting that agonist-induced beta2-adrenergic receptor downregulation resulted largely from cAMP-independent mechanisms. These results indicate that during agonist-induced downregulation, a significant fraction of beta2-adrenergic receptors are specifically sorted to lysosomes via the endosomal pathway, where receptor degradation by cysteine proteases occurs. These results provide a cellular explanation for the loss of radioligand binding sites that occurs during prolonged exposure to agonist.

Adrenergic beta-2 Receptor Agonists↗

PubMed1998

Salmeterol-induced desensitization, internalization and phosphorylation of the human beta2-adrenoceptor.

1. Partial agonists of the beta2-adrenoceptor which activate adenylyl cyclase are widely used as bronchodilators for the relief of bronchoconstriction accompanying many disease conditions, including bronchial asthma. The bronchodilator salmeterol has both a prolonged duration of action in bronchial tissue and the ability to reassert this activity following the temporary blockade of human beta2-adrenoceptors with antagonist. 2. We have compared the activation and desensitization of human beta2-adrenoceptor stimulation of adenylyl cyclase induced by salmeterol, adrenaline and salbutamol in a human lung epithelial line, BEAS-2B, expressing beta2-adrenoceptor levels of 40-70 fmol mg(-1), and in human embryonic kidney (HEK) 293 cell lines expressing 2-10 pmol mg(-1). The efficacy observed for the stimulation of adenylyl cyclase by salmeterol was only approximately 10% of that observed for adrenaline in BEAS-2B cells expressing low levels of beta2-adrenoceptor, but similar to adrenaline in HEK 293 cells expressing very high levels of receptors. Salmeterol pretreatment of these cells induced a rapid and stable activation of adenylyl cyclase activity which resisted extensive washing and beta2-adrenoceptor antagonist blockade, consistent with binding to a receptor exosite and/or to partitioning into membrane lipid. 3. The desensitization and internalization of beta2-adrenoceptors induced by the partial agonists salmeterol and salbutamol were considerably reduced relative to the action of adrenaline. Consistent with these observations, the initial rate of phosphorylation of the receptor induced by salmeterol and salbutamol was much reduced in comparison to adrenaline. 4. Our data suggest that the reduction in the rapid phase of desensitization of beta2-adrenoceptors after treatment with salmeterol or salbutamol is caused by a decrease in the rate of beta2-adrenoceptor kinase (betaARK) phosphorylation and internalization. In contrast, the rate of cyclic AMP-dependent protein kinase (PKA)-mediated phosphorylation by these partial agonists appears to be similar to adrenaline.

Adenylyl Cyclases↗

PubMed1998

Incidence of end-stage renal disease in medically treated patients with severe bilateral atherosclerotic renovascular disease.

Incidence of end-stage renal disease in medically treated patients with severe bilateral atherosclerotic renovascular disease. Atherosclerotic renovascular disease is an important cause of end-stage renal disease (ESRD). The exact incidence of ESRD and the rate of decline in glomerular filtration rate (GFR) in patients with this condition is unknown. We report the mortality, the rate of decline in renal function, and incidence of ESRD in 51 patients with bilateral atherosclerotic renovascular disease followed-up for a median period of 52 months. None of these patients had undergone any surgical or radiological intervention. Renal function was determined by serial measurements of serum creatinine. Bilateral atherosclerotic renovascular disease was associated with a high mortality rate; the crude mortality rate at 60 months was 45%. Assessment of renal function showed impaired renal function at time of angiography and a nonuniform and variable decline in renal function during the period of observation. The median GFR decreased from 39 mL/min (range, 15 to 80 mL/min) at time of angiography to 31 mL/min (range, 10 to 70 mL/min) and 24 mL/min (range, 10 to 40 mL/min) at 24 and 60 months, respectively (P < 0.05). The calculated mean rate of decline in GFR for all patients was 4 mL/min/yr (range, 1 to 16 mL/min/yr). Over the 5 years, there was a progressive increase in the incidence of ESRD. Of the original 51 patients who underwent angiography, six patients reached ESRD. The crude incidence of ESRD was, therefore, 12%. Patients who reached ESRD were characterized by advanced azotemia at the time of angiography (median GFR, 25 mL/min) and a rapid decline in GFR (8 mL/min) compared with patients who did not reach ESRD during the observation period (median GFR, 43 mL/min and an average rate of decline GFR of 3 mL/min).

Arteriosclerosis↗

PubMed1998

Long-acting inhaled beta2-agonists in asthma therapy.

OBJECTIVE: To review the pharmacology of the long-acting inhaled beta2-agonists, salmeterol and formoterol, summarize results of their clinical trials, evaluate their safety records, and discuss their roles in the treatment of asthma. DATA SOURCES: Preclinical and clinical studies involving salmeterol or formoterol were identified by a MEDLINE search, weekly computerized literature updates, and manual searches. Studies of satisfactory quality were chosen for review. DATA SYNTHESIS: Salmeterol and formoterol are potent and selective beta2-adrenoceptor agonists with durations of action >12 h. Their major differences are that formoterol has a rapid onset of action and is a partial agonist of high intrinsic efficacy, whereas salmeterol has a delayed onset and is a partial agonist of low intrinsic efficacy. Twice daily use of either drug results in improved lung function, reduced symptoms, and a better quality of life. These agents protect against exercise-induced asthma for 12 h and eliminate nighttime awakening in most patients. Limited tolerance develops, especially to their bronchoprotective effects, but their improvement of lung function is sustained. CONCLUSIONS: Regular use of salmeterol or formoterol provides subjective and objective amelioration of asthma in patients experiencing excessive symptoms or physiologic impairment despite the regular administration of low doses of inhaled corticosteroids (equivalent to approximately 500 microg/d of beclomethasone). Intermittent use of either long-acting beta2-agonist can provide prolonged protection against exercise-induced asthma or nighttime symptoms. Patients should be instructed to continue taking inhaled steroids when long-acting beta2-agonists are administered on a regular schedule and to not take long-acting beta2-agonists between regularly scheduled doses. Used properly, they are effective and safe adjunctive agents in the treatment of asthma.

Adrenergic beta-Agonists↗

PubMed1998

Previous breast biopsy for benign disease rarely complicates or alters interpretation on screening mammography.

OBJECTIVE: It has been suggested that breast screening leads to too many biopsies for benign disease that permanently scar the breast and confuse the interpretation of subsequent mammograms. We undertook retrospective and prospective studies to determine how often an excisional biopsy for benign breast disease complicates or alters interpretation of screening mammograms. MATERIALS AND METHODS: Retrospective review of our screening center database yielded 31,025 asymptomatic patients who had routine mammographic screening studies between 1993 and 1996. Of the 58,538 examinations of these patients, 53,510 were of patients who had no history of breast biopsy and 5028 were of patients who had a history of breast biopsy for benign disease. Recall rates were compared between the two groups. In the prospective study, radiologists reviewed the mammograms of 1997 consecutive patients presenting to the screening center, 173 of whom reported a prior breast biopsy for benign disease. The radiologist interpreting the images determined how often evidence of the biopsy site was apparent on the mammogram and how often such changes necessitated additional imaging. RESULTS: In the retrospective study, 3296 (6%) of the 53,510 studies done in patients who did not have a biopsy for benign disease and 360 (7%) of the 5028 studies done in women who had a biopsy for benign disease led to additional imaging. Eight recalls for further imaging (0.16%) among the 5028 studies in women with a prior biopsy for benign disease were related to the biopsy site. In the prospective study, 24 (14%) of the 173 women who had a biopsy for benign disease had mammographic evidence of the biopsy site. Nine (5%) of the 173 women who had previously had a biopsy for benign disease and 86 (5%) of the 1824 patients without a prior biopsy were recalled for additional imaging. No women were recalled because a previous breast biopsy for benign disease led to confusion or diagnostic concern. CONCLUSION: Changes in patients' breasts due to previous excisional biopsies for benign breast disease rarely pose a diagnostic dilemma in the interpretation of routine screening mammograms.

Biopsy↗

PubMed1997

Screening mammography: effect of national guidelines on current physician practice.

PURPOSE: To evaluate the effect of national breast cancer screening guidelines on current physician attitudes toward and practice of screening mammography. MATERIALS AND METHODS: Questionnaire responses from 278 physicians were analyzed. The questionnaire had four sections: general information on physician practice and experience, current use of breast cancer screening, perceptions of screening mammography, and physician awareness of and response to the controversy in breast cancer screening. RESULTS: In women aged 40-49 years, 144 (52%) of 278 physicians performed annual clinical breast examination and screening mammography every 2 years; 57 (21%) favored annual mammography and clinical breast examination. In women aged 50 years and older, 232 (83%) physicians screened patients annually with clinical breast examination and mammography. Two hundred seventeen (78%) physicians were aware of the recommended changes in screening guidelines; 54 (19%) were not aware of the changes. Of those aware of the changes, 56 (26%) changed to the new guidelines, 150 (69%) did not change, and six (3%) modified their practice somewhat. CONCLUSION: Physician practice as regards screening mammography is influenced by national guidelines.

Adult↗

PubMed1997

Should women with implants or a history of treatment for breast cancer be excluded from mammography screening programs?

OBJECTIVE: Our objective was to determine whether it is scientifically justified to require that women with implants or a history of treatment for breast cancer be screened in a diagnostic mammography setting and that they be excluded from mammography screening programs. MATERIALS AND METHODS: The recall rates for women with breast implants or a history of treatment for breast cancer who were screened in a dedicated mammography screening program were compared with those of other women in the screening program. The computerized records for the breast screening program of the Department of Radiology at our institution for January 1, 1990, through December 31, 1995, were reviewed. The recall rates for women who had breast implants and those for women with a history of treatment for breast cancer were compared with the recall rates for the other women who underwent screening. Each recall rate included women who were called back for additional evaluation in addition to those for whom a biopsy was recommended on the basis of the screening study. RESULTS: Of 45,134 screening examinations done during the review period, 43,454 (96%) were for women who had no history of breast cancer or of breast implants; 590 (1%) were for women who had undergone mastectomy; 991 (2%) were for women who had been treated with lumpectomy and irradiation for breast cancer; and 99 (0.2%) were for women with breast implants. Among the 43,454 examinations of women with no history of breast cancer or implants, 3081 examinations (7%) led to interpretations that produced requests for the patient to return for additional evaluation. Thirty-six women who had been treated for breast cancer by mastectomy were recalled (6%). Seventy-five women who had undergone lumpectomy and irradiation for breast cancer were recalled (8%). Five women with breast implants were recalled (5%). Statistically, these rates were not significantly different. CONCLUSION: We find no scientific reason to exclude women who have been treated for breast cancer or who have breast implants from dedicated screening programs.

Breast Implants↗

PubMed1996

UK multicentre study to assess the safety and tolerability of Neoral in stable renal transplant patients. UK Neoral Study Group.

The safety and tolerability of transferring maintained renal transplant patients from Sandimmun to Neoral is being assessed in a multicentre, open-label, single-arm study. A total of 250 patients has been enrolled and results are available from 75 patients up to 12 months post-transfer. A slight trend to higher mean cyclosporin trough levels was seen in this cohort, but trough levels were unchanged in the sub-group receiving > or = 1 dose changes. The mean dose fell by 13%. Creatinine levels showed a slight overall upward trend. Blood pressure and uric acid were unchanged and adverse events were typical of those seen with Sandimmun. Neoral was well-tolerated. Data from the full cohort of 250 patients up to 3 months post-transfer support these findings. These results indicate that transfer from Sandimmun to Neoral is safe and well-tolerated and provides appropriate immunosuppression at a lower average dose than Sandimmun. The Neoral dose should be adjusted promptly, as required, to maintain the target trough level.

Adolescent↗

PubMed1996

Factors influencing plasma lipid profiles including lipoprotein (a) concentrations in renal transplant recipients.

Fasting plasma cholesterol, triglycerides, high-density lipoprotein (HDL) and apoprotein (apo) B were elevated in 214 nondiabetic renal transplant recipients when compared to a reference group. Apo (a) was slightly but not significantly lower in transplant recipients (median 118 mg/dl, range 16-1680 vs 130 mg/dl, 10-1176) and this difference could be predicted from Lp (a) isoform analysis. Cholesterol, triglyceride, apo B and apo (a) concentrations correlated negatively with creatinine clearance but none of these parameters showed a significant association with proteinuria. Patients treated with steroids had higher plasma HDL concentrations than those receiving cyclosporin monotherapy (P < 0.01). The use of diuretics was associated with raised triglycerides (P < 0.001) and cholesterol (P < 0.01) and with reduced HDL (P < 0.01) whilst patients receiving beta-blockers had significantly higher triglycerides (P < 0.01) and lower HDL levels (P < 0.02). In multiple regression analysis, age (P < 0.01), creatinine clearance (P < 0.05) and diuretic therapy (P < 0.005) were independent risk factors for increased cholesterol whilst apo (a) levels correlated negatively with creatinine clearance (P < 0.005). These results suggest that impaired renal function, steroids and non-immunosuppressive drugs contribute to lipid abnormalites in renal transplant recipients.

Adrenergic beta-Antagonists↗

PubMed1996

Reduced dose OKT3 prophylaxis in sensitised kidney recipients.

Prophylactic use of the monoclonal antibody OKT3 has been studied for the prevention of rejection in sensitised renal transplant recipients. Patients receiving a full dose (FD) regimen were compared to a subsequent consecutive group of patients receiving a reduced dose (RD) regimen. The characteristics of the two groups were not significantly different with regard to age, HLA mismatch and panel-reactive antibody (PRA) status. The number of days that OKT3 was given was 12.9 +/- 1.8 for the FD regimen and 11.3 +/- 2.8 for the RD regimen. The total dose of OKT3 given was 64.4 +/- 9 mg (FD) and 38.3 +/- 8.5 mg (RD). Patient survival at 12 months was 8/8 for FD and 17/17 for RD. Graft survival at 12 months was 7/8 for FD and 17/17 for RD. Creatinine at 24 months was 185 +/- 68 and 201 +/- 81 mumol/l for FD and RD, respectively. A reduced dose regimen of OKT3 produced excellent and comparable results to the standard recommended full-dose regimen. The cost per patient was reduced 40% from 5676 pounds for FD to 3344 pounds for RD.

Adult↗

PubMed1996

HLA-DQ gene polymorphism in primary IgA nephropathy in three European populations.

MHC Class II genes may contribute to susceptibility to IgA nephropathy (IgAN). We have previously identified a restriction fragment length polymorphism (RFLP) of the DQB1 region that associated with IgAN in British Caucasoids. However, another group, while demonstrating a DQB1 association, was unable to confirm our finding. MHC molecules are heterodimers consisting of an alpha and beta chain, and thus polymorphism of the DQA1 alpha chain may also be important to disease pathogenesis in IgAN. Therefore, we have determined DQA1 alleles and re-examined DQB1 alleles in British Caucasoids with IgAN using an approach that can differentiate between the common DQ alleles; we have also extended our studies to Caucasoid populations from Northern and Southern Europe, thereby addressing the possibility of variation in genetic susceptibility between populations. DNA was prepared from IgAN patients (British, N = 105; Italian, N = 71; Finnish, N = 48) and healthy controls (British, N = 111; Italian, N = 63; Finnish, N = 41). DQA1 alleles were identified by TaqI RFLP and Southern blotting; alleles that could not be fully resolved by Taq Southern blotting were identified by PCR-RFLP. DQB1 alleles were identified by polymerase chain reaction (PCR) based technique (PCR-RFLP). No consistent association of DQ alleles were found between the populations studied. In British patients a decreased frequency of DQB1*0201 was observed (P = 0.008), in Finnish patients a decreased frequency of DQB1*0602 was observed (P = 0.01), and in Italian patients no association between DQ markers and IgAn was found. These data demonstrate population variation in disease association, but no strong or consistent association in the DQ region.

Alleles↗

PubMed1996

In vitro and in vivo persistence of reticulocytes from donor red cells.

BACKGROUND: Reticulocytes are important in the phenotyping of transfused patients. Reticulocytes can persist in blood units for the shelf life of the unit. STUDY DESIGN AND METHODS: Temperature dependence of reticulocyte persistence was examined in vitro at 4, 24, and 37 degrees C by using thiazole orange staining and flow cytometric analysis. Two-color flow cytometric analysis was used to evaluate the persistence of donor reticulocytes in transfused patients. RESULTS: Flow cytometric analysis using thiazole orange demonstrated that persistence of reticulocytes in units of stored CPDA-1 blood was temperature-dependent. Reticulocytes disappeared over 13 and 6 days at 24 degrees C and 37 degrees C, respectively, but at 4 degrees C the reticulocyte count changed little over 35 days. Two-color flow cytometric analysis of reticulocyte antigens was used to follow donor reticulocytes in 14 transfusion events in nine different patients. Donor reticulocytes persisted through 24 hours in 75 percent of the patients and were detectable at 48 hours in three patients. CONCLUSION: This study demonstrates that reticulocytes persist during refrigerated storage; they are detectable in the circulation of most recipients for the first 24 hours after transfusion and in the circulation of a few recipients after 48 hours. These findings may have relevance for separation techniques based on reticulocyte density in samples drawn shortly after transfusion and for evaluation of reticulocyte counts in patients with hematologic abnormalities.

Blood Donors↗