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1.
Allergy ; 73(9): 1871-1880, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29688579

ABSTRACT

BACKGROUND: Effective inhibition of plasma kallikrein may have significant benefits for patients with hereditary angioedema due to deficiency of C1 inhibitor (C1-INH-HAE) by reducing the frequency of angioedema attacks. Avoralstat is a small molecule inhibitor of plasma kallikrein. This study (OPuS-2) evaluated the efficacy and safety of prophylactic avoralstat 300 or 500 mg compared with placebo. METHODS: OPuS-2 was a Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group study. Subjects were administered avoralstat 300 mg, avoralstat 500 mg, or placebo orally 3 times per day for 12 weeks. The primary efficacy endpoint was the angioedema attack rate based on adjudicator-confirmed attacks. RESULTS: A total of 110 subjects were randomized and dosed. The least squares (LS) mean attack rates per week were 0.589, 0.675, and 0.593 for subjects receiving avoralstat 500 mg, avoralstat 300 mg, and placebo, respectively. Overall, 1 subject in each of the avoralstat groups and no subjects in the placebo group were attack-free during the 84-day treatment period. The LS mean duration of all confirmed attacks was 25.4, 29.4, and 31.4 hours for the avoralstat 500 mg, avoralstat 300 mg, and placebo groups, respectively. Using the Angioedema Quality of Life Questionnaire (AE-QoL), improved QoL was observed for the avoralstat 500 mg group compared with placebo. Avoralstat was generally safe and well tolerated. CONCLUSIONS: Although this study did not demonstrate efficacy of avoralstat in preventing angioedema attacks in C1-INH-HAE, it provided evidence of shortened angioedema episodes and improved QoL in the avoralstat 500 mg treatment group compared with placebo.


Subject(s)
Angioedemas, Hereditary/prevention & control , Enzyme Inhibitors/therapeutic use , Plasma Kallikrein/antagonists & inhibitors , Administration, Oral , Adult , Angioedemas, Hereditary/diagnosis , Angioedemas, Hereditary/drug therapy , Disease Progression , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/adverse effects , Enzyme Inhibitors/pharmacokinetics , Female , Humans , Male , Middle Aged , Quality of Life , Recurrence , Treatment Outcome
2.
Allergy ; 71(12): 1676-1683, 2016 12.
Article in English | MEDLINE | ID: mdl-27154593

ABSTRACT

BACKGROUND: Avoralstat is a potent small-molecule oral plasma kallikrein inhibitor under development for treatment of hereditary angioedema (HAE). This first-in-human study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of avoralstat. METHODS: This double-blind, placebo-controlled, ascending-dose cohort trial evaluated avoralstat single doses of 50, 125, 250, 500, and 1000 mg and multiple doses up to 2400 mg daily (100, 200, 400, and 800 mg every 8 h [q8 h] up to 7 days). RESULTS: Avoralstat (n = 71) was generally well tolerated with no signals for a safety concern; there were no serious adverse events (AEs) or discontinuations due to AEs, and compared to placebo (n = 18), no notable difference in AEs. Four moderate severity AEs were reported in two subjects; syncope after a single 250 mg dose (one subject) and abdominal pain, back pain, and eczema after multiple doses of 800 mg avoralstat (one subject). For multiple-dose cohorts, the incidence of gastrointestinal AEs was highest at the 2400 mg/day dose. Elimination of avoralstat was bi-exponential with a terminal half-life of 12-31 h. Inhibition of plasma kallikrein was observed at all doses, and the degree of inhibition was highly correlated with avoralstat concentrations (R = 0.93). Mean avoralstat concentrations at doses ≥400 mg q8 h met or exceeded plasma kallikrein EC50 values throughout the dosing interval. CONCLUSION: Avoralstat was well tolerated, and drug exposure was sufficient to meet target levels for inhibition of plasma kallikrein. Based on these results, the 400 mg q8 h dose was selected for further evaluation in patients with HAE.


Subject(s)
Angioedemas, Hereditary/drug therapy , Plasma Kallikrein/antagonists & inhibitors , Protease Inhibitors/administration & dosage , Protease Inhibitors/pharmacokinetics , Administration, Oral , Adolescent , Adult , Drug Administration Schedule , Drug Monitoring , Female , Humans , Male , Middle Aged , Protease Inhibitors/adverse effects , Time Factors , Treatment Outcome , Young Adult
3.
JMIR Mhealth Uhealth ; 4(1): e5, 2016 Jan 20.
Article in English | MEDLINE | ID: mdl-26792225

ABSTRACT

BACKGROUND: Despite the recent explosion of the mobile health (mHealth) industry and consumer acquisition of mHealth tools such as wearable sensors and applications (apps), limited information is known about how this technology can sustain health behavior change and be integrated into health care. OBJECTIVE: The objective of the study was to understand potential users' views of mHealth technology, the role this technology may have in promoting individual activity goals aimed at improving health, and the value of integrating mHealth technology with traditional health care. METHODS: Four focus groups were conducted with adults interested in sharing their views on how mHealth technology could support wellness programs and improve health. Participants (n=30) were enrolled from an employee population at an academic health institution. Qualitative thematic analysis was used to code transcripts and identify overarching themes. RESULTS: Our findings suggest that tracking health data alone may result in heightened awareness of daily activity, yet may not be sufficient to sustain use of mHealth technology and apps, which often have low reuse rates. Participants suggested that context, meaning, and health care partnerships need to be incorporated to engage and retain users. In addition to these findings, drivers for mHealth technology previously identified in the literature, including integration and control of health data were confirmed in this study. CONCLUSIONS: This study explores ways that mHealth technologies may be used to not only track data, but to encourage sustained engagement to achieve individual health goals. Implications of these findings include recommendations for mHealth technology design and health care partnership models to sustain motivation and engagement, allowing individuals to achieve meaningful behavior change.

4.
J Mech Behav Biomed Mater ; 8: 58-70, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22402154

ABSTRACT

Several challenges persist when attempting to utilize decellularized tissue as a scaffold for vascular tissue engineering. Namely: poor cell infiltration/migration, excessive culture times associated with repopulating the scaffolds, and the achievement of a quiescent medial layer. In an attempt to create an optimum vascular scaffold, we customized the properties of decellularized porcine carotid arteries by: (i) creating cavities within the medial layer to allow direct injection of cells, and (ii) controlling the amount of collagen digestion to increase the porosity. Histological examination of our customized scaffold revealed a highly porous tissue structure containing consistent medial cavities running longitudinally through the porous scaffold wall. Mechanical testing of the customized scaffold showed that our minimal localized disruption to the ECM does not have a detrimental effect on the bulk mechanical response of the tissue. The results demonstrate that an increased stiffness and reduced distensibility occurs after decellularization when compared to the native tissue, however post scaffold customization we can revert the scaffold tensile properties back to that of the native tissue. This most noteworthy result occurs in the elastin dominant phase of the tensile response of the scaffold, indicating that no disruption has occurred to the elastin network by our decellularization and customization techniques. Additionally, the bulk seeding potential of the customized scaffold was demonstrated by direct injection of human smooth muscle cells through the medial cavities. The optimum cell dispersion was observed in the highest porosity scaffold, with large cell numbers retained within the medial layer after 24 h static culture. In summary, this study presents a novel customized decellularized vascular scaffold that has the capability of bulk seeding the media, and in tandem to this method, the porosity of the scaffold has been increased without compromising the mechanical integrity.


Subject(s)
Carotid Arteries/cytology , Mechanical Phenomena , Tissue Engineering/methods , Tissue Scaffolds , Animals , Biomechanical Phenomena , Carotid Arteries/metabolism , Collagen/metabolism , Humans , Materials Testing , Swine , Time Factors , Tissue Culture Techniques , Vascular Grafting
5.
Clin Pharmacol Ther ; 89(2): 172-4, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21252934

ABSTRACT

The 2009 H1N1 influenza pandemic prompted the US Food and Drug Administration (FDA) to issue an emergency use authorization (EUA) for the intravenous antiviral peramivir, an unapproved neuraminidase inhibitor (NAI) currently under development. Peramivir use was limited to patients for whom other NAI therapy had failed or in whom oral or inhalational drug absorption was believed to be unreliable. This introduced a patient selection bias that precluded safety and efficacy assessment. Despite the challenges and risks, there was a compelling public health need for an intravenous agent during the 2009 H1N1 pandemic.


Subject(s)
Antiviral Agents/therapeutic use , Cyclopentanes/therapeutic use , Drug Approval , Drug Industry , Emergency Medical Services , Guanidines/therapeutic use , Influenza A Virus, H1N1 Subtype/drug effects , Influenza, Human/drug therapy , Acids, Carbocyclic , Cyclopentanes/adverse effects , Guanidines/adverse effects , Humans , United States , United States Food and Drug Administration
6.
Ann R Coll Surg Engl ; 92(4): W38, 2010 May.
Article in English | MEDLINE | ID: mdl-20501009

ABSTRACT

A case report of spontaneous omental bleeding attributed to a combination of vigorous abdominal exercise and antiplatelet agents. This case serves to high-light the bleeding risks associated with antiplatelet therapy.


Subject(s)
Exercise , Hematoma/etiology , Omentum , Peritoneal Diseases/etiology , Platelet Aggregation Inhibitors/adverse effects , Hematoma/diagnostic imaging , Humans , Male , Middle Aged , Omentum/diagnostic imaging , Peritoneal Diseases/diagnostic imaging , Tomography, X-Ray Computed
7.
Colorectal Dis ; 11(5): 513-5, 2009 Jun.
Article in English | MEDLINE | ID: mdl-18637926

ABSTRACT

Abstract Objective Currently priority for colonoscopy is given to diagnostic and therapeutic procedures. Surveillance colonoscopies place a significant demand on the service. These are held on a separate waiting list in our institution, which is currently several years behind. The purpose of this study was to apply the BSG guidelines to this waiting list in our institution in order to ascertain whether patients are appropriately listed. Method This was a retrospective review. The patients on the waiting list whose procedures were due in 2004 and 2005 formed the study group. Information on demographics, previous colonoscopies, and indication was taken from the case notes. Results were analysed using Microsoft Excel. Results A total of 172 patients were overdue their colonoscopies. If the BSG guidelines were strictly adhered to, 49% of these patients were inappropriately listed. If applied less rigidly, 42% of patients should not have been on the list. The reasons for removal from the list were as follows: Thirty-nine patients were older than the upper age limit, 23 had had clear colonoscopies after adenomatous polyp follow up, four were listed for diverticular disease follow up, four for metaplastic polyps, one for constipation and one for per rectum (PR) bleed follow up. Conclusion With strict application of the BSG guidelines to a surveillance colonoscopy waiting list, 49% of the patients on the list do not need the procedure. It is recommended that consultant led education and control of the waiting list be used to reduce unnecessary investigations.


Subject(s)
Colonoscopy , Guideline Adherence , Waiting Lists , Adult , Age Factors , Aged , Aged, 80 and over , Colonoscopy/methods , Colonoscopy/standards , Gastroenterology , Humans , Middle Aged , Practice Guidelines as Topic , Retrospective Studies , Societies, Medical , Time Factors , United Kingdom
8.
HPB (Oxford) ; 9(3): 225-8, 2007.
Article in English | MEDLINE | ID: mdl-18333227

ABSTRACT

AIMS: To determine the prevalence of bactibilia in patients undergoing cholecystectomy and to relate the presence or absence of organisms to the preoperative and postoperative course. PATIENTS AND METHODS: Patients undergoing cholecystectomy under the care of a single consultant surgeon during a continuous 5-year period were identified from a prospectively maintained departmental database. Symptoms, clinical signs, findings of investigations, details of treatment and postoperative care were noted. Risk factors for bactibilia (acute cholecystitis, common duct stones, emergency surgery, intraoperative findings and age > 70 years) were documented. Patients were divided according to the presence (B + ) or absence (B-) of bacteria on culture of their bile. RESULTS: In all, 128/180 (70%) of cholecystectomies had full data available for analysis. Bacteria were identified in the bile of 20 (15.6%) patients (B+ group). The B+ group was significantly older at 63.78+/-9.7 versus 61.62+/-13.9 (p<0.05) and contained significantly fewer females than the B- group (p<0.05). All 20 patients (100%) in the B+ group had > or = 1 risk factor, while these factors were present in only 29/108 (30.3%) of patients in the B- group (p<0.05). The overall incidence of infective complications was 20% in the B+ group compared with 0.9% in the B- group (p<0.05) and the bile-related infections were higher in the B+ group (p<0.05). CONCLUSIONS: The study demonstrated that while patients with complicated gallstone disease frequently exhibit bactibilia, patients with uncomplicated cholelithiasis have aseptic bile. The findings would suggest that prophylactic antibiotics should be limited to patients with risk factors for bactibilia.

9.
Hernia ; 8(2): 166-8, 2004 May.
Article in English | MEDLINE | ID: mdl-14735327

ABSTRACT

BACKGROUND: Numerous complications have been described following the implantation of synthetic meshes during hernia repair; one of the rarest, with only three reported cases, is giant mature fibrous cyst formation. Our clinical experience with this complication has led us to believe that it may be more common than previously thought. METHODS: Surgical operation notes and pathology archives were reviewed for the period January 1998-January 2002 to determine the prevalence of mature cyst formation following mesh repair of hernias. RESULTS: Out of 1100 hernia repair operations involving the use of synthetic meshes in our institution during the period of study, five developed histologically confirmed mature fibrous cysts giving a prevalence of 0.45% for this complication. CONCLUSION: The formation of a giant mature cyst following mesh repair of hernias is an underreported complication.


Subject(s)
Abdominal Wall , Cysts/etiology , Hernia, Ventral/etiology , Hernia, Ventral/surgery , Postoperative Complications , Surgical Mesh/adverse effects , Abdominal Wall/surgery , Adult , Aged , Aged, 80 and over , Cysts/diagnosis , Cysts/surgery , Female , Humans , Male , Middle Aged , Obesity/complications
11.
BJU Int ; 88(3): 251-4, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11488740

ABSTRACT

OBJECTIVE: To evaluate the justification for operative intervention in patients undergoing surgery for benign scrotal pathology, and to assess the associated morbidity. PATIENTS AND METHODS: Consecutive patients in two surgical firms who underwent surgery for benign intrascrotal pathology over a 5-year period were studied retrospectively. RESULTS: In all, 102 patients were included in the study (mean age 51.6 years, range 16-86). Most patients had either epididymal cysts (59) or hydroceles (31) or a combination of the two (eight). Some patients (37) underwent ultrasonography before surgery. The indications for surgery were deemed to be strong in 25% of patients but weak or absent in the remainder. Complications occurred in 31 patients, being minor in 18, but significant in 13, resulting in four re-admissions to hospital. There was no significant difference in the complication rate between those patients with strong indications for surgery (37%) and those with weak indications (28%). CONCLUSIONS: Surgery for benign intrascrotal pathology is frequently undertaken for weak clinical indications and carries significant associated morbidity. This could be avoided in many cases by simple reassurance. Judicious use of ultrasonography is advised. A policy of selective surgical intervention is strongly advocated.


Subject(s)
Genital Diseases, Male/pathology , Scrotum/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Cysts/diagnostic imaging , Cysts/pathology , Cysts/surgery , Follow-Up Studies , Genital Diseases, Male/diagnostic imaging , Genital Diseases, Male/surgery , Humans , Length of Stay , Male , Middle Aged , Scrotum/pathology , Spermatocele/diagnostic imaging , Spermatocele/pathology , Spermatocele/surgery , Ultrasonography , Varicocele/diagnostic imaging , Varicocele/pathology , Varicocele/surgery
12.
Blood ; 98(5): 1339-45, 2001 Sep 01.
Article in English | MEDLINE | ID: mdl-11520780

ABSTRACT

The recombinant thrombopoietins have been shown to be effective stimulators of platelet production in cancer patients. It was therefore of interest to determine if one of these, pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), could be used to increase platelet counts and consequently platelet yields from apheresis in healthy platelet donors. In a blinded, 2-cycle, crossover study, 59 platelet donors were randomized to receive a single subcutaneous injection of PEG-rHuMGDF (1 microg/kg or 3 microg/kg) or placebo and 15 days later undergo platelet apheresis. Donors treated with placebo had a median peak platelet count after PEG-rHuMGDF injection of 248 x 10(9)/L compared with 366 x 10(9)/L in donors treated with 1 microg/kg PEG-rHuMGDF and 602 x 10(9)/L in donors treated with 3 microg/kg PEG-rHuMGDF. The median maximum percentage that platelet counts increased from baseline was 10% in donors who received placebo compared with 70% in donors who received 1 microg/kg and 167% in donors who received 3 microg/kg PEG-rHuMGDF. There was a direct relationship between the platelet yield and the preapheresis platelet count: Placebo-treated donors provided 3.8 x 10(11) (range 1.3 x 10(11)-7.9 x 10(11)) platelets compared with 5.6 x 10(11) (range 2.6 x 10(11)-12.5 x 10(11)) or 11.0 x 10(11) (range 7.1 x 10(11)-18.3 x 10(11)) in donors treated with 1 microg/kg or 3 microg/kg PEG-rHuMGDF, respectively. Substandard collections (<3 x 10(11) platelets) were obtained from 26%, 4%, and 0% of the placebo, 1 microg/kg, and 3 microg/kg donors, respectively. No serious adverse events were reported; nor were there events that met the criteria for dose-limiting toxicity. Thrombopoietin therapy can increase platelet counts in healthy donors to provide a median 3-fold more apheresis platelets compared with untreated donors.


Subject(s)
Blood Donors , Platelet Count , Plateletpheresis , Polyethylene Glycols/pharmacology , Recombinant Proteins/pharmacology , Thrombopoietin/pharmacology , Adult , Cross-Over Studies , Dose-Response Relationship, Drug , Female , Headache/chemically induced , Humans , Injections, Subcutaneous , Male , Middle Aged , Platelet Function Tests , Polyethylene Glycols/administration & dosage , Polyethylene Glycols/adverse effects , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , Safety , Thrombopoietin/administration & dosage , Thrombopoietin/adverse effects
13.
Genetics ; 159(4): 1717-26, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11779809

ABSTRACT

Negative interference describes a situation where two genetic regions have more double crossovers than would be expected considering the crossover rate of each region. We detected negative crossover interference while attempting to genetically map translocation breakpoints in maize. In an attempt to find precedent examples we determined there was negative interference among previously published translocation breakpoint mapping data in maize. It appears that negative interference was greater when the combined map length of the adjacent regions was smaller. Even positive interference appears to have been reduced when the combined lengths of adjacent regions were below 40 cM. Both phenomena can be explained by a reduction in crossovers near the breakpoints or, more specifically, by a failure of regions near breakpoints to become competent for crossovers. A mathematical explanation is provided.


Subject(s)
Crossing Over, Genetic , Heterozygote , Translocation, Genetic , Zea mays/genetics , Chromosome Mapping , Crosses, Genetic , Homozygote , Models, Genetic , Models, Theoretical
14.
Plant Physiol ; 124(1): 355-68, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10982449

ABSTRACT

Phytic acid (myo-inositol-1, 2, 3, 4, 5, 6-hexakisphosphate or Ins P(6)) typically represents approximately 75% to 80% of maize (Zea mays) seed total P. Here we describe the origin, inheritance, and seed phenotype of two non-lethal maize low phytic acid mutants, lpa1-1 and lpa2-1. The loci map to two sites on chromosome 1S. Seed phytic acid P is reduced in these mutants by 50% to 66% but seed total P is unaltered. The decrease in phytic acid P in mature lpa1-1 seeds is accompanied by a corresponding increase in inorganic phosphate (P(i)). In mature lpa2-1 seed it is accompanied by increases in P(i) and at least three other myo-inositol (Ins) phosphates (and/or their respective enantiomers): D-Ins(1,2,4,5,6) P(5); D-Ins (1,4,5,6) P(4); and D-Ins(1,2,6) P(3). In both cases the sum of seed P(i) and Ins phosphates (including phytic acid) is constant and similar to that observed in normal seeds. In both mutants P chemistry appears to be perturbed throughout seed development. Homozygosity for either mutant results in a seed dry weight loss, ranging from 4% to 23%. These results indicate that phytic acid metabolism during seed development is not solely responsible for P homeostasis and indicate that the phytic acid concentration typical of a normal maize seed is not essential to seed function.


Subject(s)
Phytic Acid/metabolism , Seeds/physiology , Zea mays/physiology , Electrophoresis/methods , Inositol Phosphates/chemistry , Inositol Phosphates/metabolism , Magnetic Resonance Spectroscopy , Mutation , Phenotype , Phosphates/isolation & purification , Phosphates/metabolism , Physical Chromosome Mapping , Phytic Acid/biosynthesis , Seeds/growth & development , Stereoisomerism , Zea mays/genetics , Zea mays/growth & development
15.
Oncologist ; 5(2): 162-8, 2000.
Article in English | MEDLINE | ID: mdl-10794807

ABSTRACT

Prostate cancer has become the most common cancer among American men and is second only to lung cancer as a cause of male cancer-related death. Several treatment options exist for different stages of prostate cancer including observation, prostatectomy, radiation therapy, chemotherapy, and hormone therapy. Hormone therapy has evolved from the use of estrogens to gonadotropin-releasing hormone (GnRH) agonists and recently, investigational GnRH antagonists. GnRH receptor agonists such as leuprolide, bruserelin and goserelin have been used for the treatment of prostate cancer. These agonists eventually cause the inhibition of lutenizing hormone production, which in turn causes a suppression of testosterone and dihydrotestosterone, on which continued growth of prostate cancer cells depend. Several comparative studies of leuprorelin administered as daily injections or monthly depot injections have been reported. Disease progression was prevented in more than 72% of men administered daily leuprorelin, and in 82% to 89% of those receiving monthly depots. Another synthetic GnRH analog, goserelin, has been studied in a similar population of men with daily injections producing partial responses in 60% to 80% of men with previously untreated prostate cancer. Abarelix, a peptide antagonist of GnRH receptor, is also being studied for the treatment of prostate cancer. The discovery and development of GnRH antagonists may provide an important advance for patients with prostate cancer. Clearly the studies described herein, as well as many others, outline an exciting era of research to define the optimal use of hormonal therapy in prostate cancer.


Subject(s)
Antineoplastic Agents, Hormonal/therapeutic use , Gonadotropin-Releasing Hormone/antagonists & inhibitors , Prostatic Neoplasms/therapy , Testosterone/pharmacology , Antineoplastic Agents, Hormonal/pharmacology , Buserelin/pharmacology , Buserelin/therapeutic use , Goserelin/pharmacology , Goserelin/therapeutic use , Humans , Leuprolide/pharmacology , Leuprolide/therapeutic use , Male , Prostatic Neoplasms/physiopathology
16.
Eur J Surg Oncol ; 26(1): 95-8, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10718188

ABSTRACT

Port-site metastasis following laparoscopic cholecystectomy with unsuspected gallbladder carcinoma is a serious problem. We reviewed 45 such cases reported in the English literature to date, and add another case which occurred in a 72-year-old female 13 months after a laparoscopic cholecystectomy for gallstones, who also had an unapparent gallbladder carcinoma. Pre-operative diagnosis of gallbladder carcinoma is possible in less than 10% of cases, with a high index of suspicion. If detected during laparoscopy early conversion to open procedure is recommended. If diagnosed later, however, to contemplate further radical operation depending on histopathology would be unwise as a universal approach, because of increased associated morbidity and mortality. The prospect of cure is also very unrealistic in this condition.


Subject(s)
Adenocarcinoma/secondary , Cholecystectomy, Laparoscopic/adverse effects , Cholelithiasis/complications , Gallbladder Neoplasms/pathology , Skin Neoplasms/secondary , Aged , Cholelithiasis/surgery , Fatal Outcome , Female , Gallbladder Neoplasms/complications , Humans , Neoplasm Seeding
17.
Dev Genes Evol ; 210(6): 300-10, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11180835

ABSTRACT

Using confocal laser scanning microscopy we have characterized early and intermediate stages of maize wild-type embryogenesis and compared to mutant development of four different embryo-specific mutations, emb*-8518, emb*-8521, emb*-8537, and emb*-8542. Confocal laser scanning microscopy is well suited to study embryo development in maize in a nondisruptive manner from shortly after fertilization to late stages in embryogenesis. The analysis of the mutant morphology indicated that two of the recessive mutations, emb*-8518 and emb*-8521, cause an early developmental arrest in the proembryo/early transition stage: mutant embryos are unable to enter the morphogenetic phase of embryogenesis. In contrast, homozygous emb*-8537, and emb*-8542 embryos progress at least to the coleoptilar stage and sometimes establish a functional shoot meristem that can determine leaf primordia. The morphological characterization of mutants was confirmed by analysis of the expression pattern of three different marker genes: Lipid transfer protein 2, Zea mays Outer Cell Layer 1, and Knotted 1. Our data indicate that both emb*-8518 and emb*-8521 mutant embryos are impaired in restriction of ZmOCL1 transcripts to the embryonic protoderm and therefore fail to establish a normal radial organization. In contrast, emb*-8537 and emb*-8542 embryos exhibit the wild-type pattern and proceed in development to the formation of a shoot apical meristem and the establishment of bilateral symmetry.


Subject(s)
Mutation , Seeds/growth & development , Zea mays/genetics , Base Sequence , DNA Primers , Homozygote , Phenotype , Seeds/metabolism
18.
Blood ; 95(8): 2514-22, 2000 Apr 15.
Article in English | MEDLINE | ID: mdl-10753829

ABSTRACT

The effects of thrombopoietic stimulation on megakaryocytopoiesis, platelet production, and platelet viability and function were examined in normal volunteers randomized to receive single bolus subcutaneous injections of 3 microg/kg pegylated recombinant megakaryocyte growth and development factor (PEG-rHuMGDF) or placebo in a 3:1 ratio. PEG-rHuMGDF transiently doubled circulating platelet counts, from 237 +/- 41 x 10(3)/microL to 522 +/- 90 x 10(3)/microL (P <.0001), peaking on day 12. Baseline and day-12 samples showed no differences in responsiveness of platelets to adenosine diphosphate or thrombin receptor agonist peptide (P >.4 in all cases); expression of platelet ligand-induced binding sites or annexin V binding sites (P >.6 in both cases); or density of platelet TPO-receptors (P >.5). Platelet counts normalized by day 28. The life span of autologous (111)In-labeled platelets increased from 205 +/- 18 hours (baseline) to 226 +/- 22 hours (P <.01) on day 8. Platelet life span decreased from 226 +/- 22 hours (day 8) to 178 +/- 53 hours (P <.05) on day 18. The theoretical basis for senescent changes in mean platelet life span was illustrated by biomathematical modeling. Platelet turnover increased from 43.9 +/- 11.9 x 10(3) platelets/microL/d (baseline) to 101 +/- 27.6 x 10(3) platelets/microL/d (P =.0009), and marrow megakaryocyte mass expanded from 37.4 +/- 18.5 fL/kg to 62 +/- 17 x 10(10) fL/kg (P =. 015). Although PEG-rHuMGDF initially increased megakaryocyte volume and ploidy, subsequently ploidy showed a transient reciprocal decrease when the platelet counts exceeded placebo values. In healthy human volunteers PEG-rHuMGDF transiently increases megakaryocytopoiesis 2-fold. Additionally, peripheral platelets expand correspondingly and exhibit normal function and viability during the ensuing 10 days. The induced perturbation in steady state thrombopoiesis resolves by 4 weeks. (Blood. 2000;95:2514-2522)


Subject(s)
Blood Platelets/drug effects , Blood Platelets/physiology , Polyethylene Glycols/pharmacology , Thrombopoietin/pharmacology , Blood Platelets/cytology , Cell Differentiation/drug effects , Hematopoiesis/drug effects , Humans , Platelet Activation/drug effects , Platelet Count/drug effects , Recombinant Proteins/pharmacology
19.
Genetics ; 153(2): 933-41, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10511568

ABSTRACT

In angiosperm ovules and anthers, the hypodermal cell layer provides the progenitors of meiocytes. We have previously reported that the multiple archesporial cells1 (mac1) mutation identifies a gene that plays an important role in the switch of the hypodermal cells from the vegetative pathway to the meiotic (sporogenous) pathway in maize ovules. Here we report that the mac1 mutation alters the developmental fate of the hypodermal cells of the maize anther. In a normal anther a hypodermal cell divides periclinally with the inner cell giving rise to the sporogenous archesporial cells while the outer cell, together with adjacent cells, forms the primary parietal layer. The cells of the parietal layer then undergo two cycles of periclinal divisions to give rise to three wall layers. In mac1 anthers the primary parietal layer usually fails to divide periclinally so that the three wall layers do not form, while the archesporial cells divide excessively and most fail to form microsporocytes. The centrally located mutant microsporocytes are abnormal in appearance and in callose distribution and they fail to proceed through meiosis. These failures in development and function appear to reflect the failure of mac1 gene function in the hypodermal cells and their cellular progeny.


Subject(s)
Genes, Plant , Zea mays/growth & development , Zea mays/genetics , Heterozygote , Mutation , Reproduction , Seeds/physiology , Zea mays/cytology
20.
J Clin Oncol ; 17(1): 82-92, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10458221

ABSTRACT

PURPOSE: To determine the safety and efficacy of multiple cycles of dose-intensive, nonablative chemotherapy in women with poor-prognosis breast cancer. PATIENTS AND METHODS: Women with stage II breast cancer and 10 or more involved nodes or four or more involved nodes and estrogen receptor-negative tumors and women with stage III disease received three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2, with progenitor cell and filgrastim support every 28 days (n = 79) or 21 days (n = 20). Patients were reviewed at least twice yearly thereafter. Twenty-six patients had bone marrow and apheresis collections assessed for the presence of micrometastatic tumor cells. RESULTS: Ninety-nine women (median age, 43 years; range, 24 to 60 years) were treated. Ninety-two completed all three cycles of chemotherapy. The major toxicity was severe, reversible myelosuppression that was more prolonged with successive cycles, and this did not differ between patients given treatment every 28 days and those treated every 21 days. Febrile neutropenia occurred in 176 (61%) of 287 cycles. Severe mucositis (grade 3 or 4) occurred in 23% of cycles but tended to be short-lived and was reversible. The cardiac ejection fraction fell by a median of 4% during treatment, and three patients developed evidence of cardiac failure after chemotherapy. Two patients (2%) died of acute toxicity. Three of 26 patients had evidence of circulating micrometastatic tumor cells. The actuarial distant disease-free and overall survival rates at 60-month follow-up were 64% (95% confidence interval [CI], 53% to 75%) and 67% (95% CI, 56% to 78%), respectively. CONCLUSION: Multiple cycles of dose-intensive, nonablative chemotherapy is a feasible and safe approach. Disease control and survival are similar to those in other studies of myeloablative chemotherapy in poor-prognosis breast cancer. The regimen is being evaluated in a randomized trial of the International Breast Cancer Study Group.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Granulocyte Colony-Stimulating Factor/therapeutic use , Hematopoietic Stem Cell Mobilization , Hematopoietic Stem Cell Transplantation , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Breast Neoplasms/therapy , Combined Modality Therapy , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Epirubicin/administration & dosage , Epirubicin/adverse effects , Female , Filgrastim , Follow-Up Studies , Humans , Middle Aged , Neoplastic Cells, Circulating , Prognosis , Recombinant Proteins , Survival Rate
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