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1.
Glob Chang Biol ; 30(6): e17364, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38864329

ABSTRACT

Thermal regimes of aquatic ecosystems are predicted to change as climate warming progresses over the next century, with high-latitude and high-elevation regions predicted to be particularly impacted. Here, we have modelled alpine stream water temperatures from air temperature data and used future predicted air temperature trajectories (representative concentration pathway [rcp] 4.5 and 8.5) to predict future water temperatures. Modelled stream water temperatures have been used to calculate cumulative degree days (CDDs) under current and future climate conditions. These calculations show that degree days will accumulate more rapidly under the future climate scenarios, and with a stronger effect for higher CDD values (e.g., rcp 4.5: 18-28 days earlier [CDD = 500]; 42-55 days earlier [CDD = 2000]). Changes to the time to achieve specific CDDs may have profound and unexpected consequences for alpine ecosystems. Our calculations show that while the effect of increased CDDs may be relatively small for organisms that emerge in spring-summer, the effects for organisms emerging in late summer-autumn may be substantial. For these organisms, the air temperatures experienced upon emergence could reach 9°C (rcp 4.5) or 12°C (rcp 8.5) higher than under current climate conditions, likely impacting on the metabolism of adults, the availability of resources, including food and suitable oviposition habitat, and reproductive success. Given that the movement of aquatic fauna to the terrestrial environment represents an important flux of energy and nutrients, differential changes in the time periods to achieve CDDs for aquatic and terrestrial fauna may de-couple existing predator-prey interactions.


Subject(s)
Climate Change , Rivers , Temperature , Animals , Aquatic Organisms/physiology , Seasons , Ecosystem , Climate Models
2.
Ann Oncol ; 30(5): 804-814, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30838379

ABSTRACT

BACKGROUND: The advent of effective adjuvant therapies for patients with resected melanoma has highlighted the need to stratify patients based on risk of relapse given the cost and toxicities associated with treatment. Here we assessed circulating tumor DNA (ctDNA) to predict and monitor relapse in resected stage III melanoma. PATIENTS AND METHODS: Somatic mutations were identified in 99/133 (74%) patients through tumor tissue sequencing. Personalized droplet digital PCR (ddPCR) assays were used to detect known mutations in 315 prospectively collected plasma samples from mutation-positive patients. External validation was performed in a prospective independent cohort (n = 29). RESULTS: ctDNA was detected in 37 of 99 (37%) individuals. In 81 patients who did not receive adjuvant therapy, 90% of patients with ctDNA detected at baseline and 100% of patients with ctDNA detected at the postoperative timepoint relapsed at a median follow up of 20 months. ctDNA detection predicted patients at high risk of relapse at baseline [relapse-free survival (RFS) hazard ratio (HR) 2.9; 95% confidence interval (CI) 1.5-5.6; P = 0.002] and postoperatively (HR 10; 95% CI 4.3-24; P < 0.001). ctDNA detection at baseline [HR 2.9; 95% CI 1.3-5.7; P = 0.003 and postoperatively (HR 11; 95% CI 4.3-27; P < 0.001] was also associated with inferior distant metastasis-free survival (DMFS). These findings were validated in the independent cohort. ctDNA detection remained an independent predictor of RFS and DMFS in multivariate analyses after adjustment for disease stage and BRAF mutation status. CONCLUSION: Baseline and postoperative ctDNA detection in two independent prospective cohorts identified stage III melanoma patients at highest risk of relapse and has potential to inform adjuvant therapy decisions.


Subject(s)
Circulating Tumor DNA/blood , Melanoma/blood , Neoplasm Recurrence, Local/blood , Skin Neoplasms/blood , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , Circulating Tumor DNA/genetics , Female , GTP Phosphohydrolases/genetics , Humans , Male , Melanoma/genetics , Melanoma/pathology , Membrane Proteins/genetics , Middle Aged , Mutation , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/genetics , Neoplasm Staging , Prognosis , Prospective Studies , Proto-Oncogene Proteins B-raf/genetics , Skin Neoplasms/genetics , Skin Neoplasms/pathology , Survival Rate , Young Adult , Melanoma, Cutaneous Malignant
3.
Ann Oncol ; 29(7): 1569-1574, 2018 07 01.
Article in English | MEDLINE | ID: mdl-29659679

ABSTRACT

Background: As early detection of recurrent melanoma maximizes treatment options, patients usually undergo post-operative imaging surveillance, increasingly with FDG-PET/CT (PET). To assess this, we evaluated stage 3 melanoma patients who underwent prospectively applied and sub-stage-specific schedules of PET surveillance. Patients and methods: From 2009, patients with stage 3 melanoma routinely underwent PET +/- MRI brain scans via defined schedules based on sub-stage-specific relapse probabilities. Data were collected regarding patient characteristics and outcomes. Contingency analyses were carried out of imaging outcomes. Results: One hundred and seventy patients (stage 3A: 34; 3B: 93; 3C: 43) underwent radiological surveillance. Relapses were identified in 65 (38%) patients, of which 45 (69%) were asymptomatic. False-positive imaging findings occurred in 7%, and 6% had treatable second (non-melanoma) malignancies. Positive predictive values (PPV) of individual scans were 56%-83%. Negative scans had predictive values of 89%-96% for true non-recurrence [negative predictive values (NPV)] until the next scan. A negative PET at 18 months had NPVs of 80%-84% for true non-recurrence at any time in the 47-month (median) follow-up period. Sensitivity and specificity of the overall approach of sub-stage-specific PET surveillance were 70% and 87%, respectively. Of relapsed patients, 33 (52%) underwent potentially curative resection and 10 (16%) remained disease-free after 24 months (median). Conclusions: Application of sub-stage-specific PET in stage 3 melanoma enables asymptomatic detection of most recurrences, has high NPVs that may provide patient reassurance, and is associated with a high rate of detection of resectable and potentially curable disease at relapse.


Subject(s)
Fluorodeoxyglucose F18 , Image Processing, Computer-Assisted/methods , Melanoma/pathology , Neoplasm Recurrence, Local/pathology , Positron Emission Tomography Computed Tomography/methods , Follow-Up Studies , Humans , Melanoma/diagnostic imaging , Melanoma/surgery , Neoplasm Recurrence, Local/diagnostic imaging , Neoplasm Recurrence, Local/surgery , Population Surveillance , Postoperative Period , Prognosis , Radiopharmaceuticals
4.
Oncogene ; 35(48): 6235-6245, 2016 12 01.
Article in English | MEDLINE | ID: mdl-27641331

ABSTRACT

Restoration of tumor suppression is an attractive onco-therapeutic approach. It is particularly relevant when a tumor suppressor is excessively degraded by an overactive oncogenic E3 ligase. We previously discovered that the E6-associated protein (E6AP; as classified in the human papilloma virus context) is an E3 ligase that has an important role in the cellular stress response, and it directly targets the tumor-suppressor promyelocytic leukemia protein (PML) for proteasomal degradation. In this study, we have examined the role of the E6AP-PML axis in prostate cancer (PC). We show that knockdown (KD) of E6AP expression attenuates growth of PC cell lines in vitro. We validated this finding in vivo using cell line xenografts, patient-derived xenografts and mouse genetics. We found that KD of E6AP attenuates cancer cell growth by promoting cellular senescence in vivo, which correlates with restoration of tumor suppression by PML. In addition, we show that KD of E6AP sensitizes cells to radiation-induced death. Overall, our findings demonstrate a role for E6AP in the promotion of PC and support E6AP targeting as a novel approach for PC treatment, either alone or in combination with radiation.


Subject(s)
Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Ubiquitin-Protein Ligases/genetics , Animals , Cell Cycle/genetics , Cell Line, Tumor , Cell Proliferation , Cell Survival/genetics , Cellular Senescence/genetics , Disease Models, Animal , Down-Regulation , Gene Expression , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Heterografts , Humans , Male , Mice , Prognosis , Promyelocytic Leukemia Protein/genetics , Promyelocytic Leukemia Protein/metabolism , Prostatic Neoplasms/mortality , RNA, Small Interfering/genetics , Stress, Physiological , Tumor Burden
6.
Zootaxa ; 3972(4): 451-81, 2015 Jun 13.
Article in English | MEDLINE | ID: mdl-26249505

ABSTRACT

The caddisfly genus Caenota Mosely 1953 (in Mosely & Kimmins 1953) currently contains 5 species known from eastern Australia. Caenota is distinguished from other Calocidae genera by having adult males with greatly expanded maxillary palpi and a large membranous process associated with the antennal scape. Of the 5 described species, the larvae of only 1 is known. Here, we describe 2 new species, Caenota cudonis sp. nov. and C. equustagna sp. nov., from adult, larval, and pupal material. Also, we describe for the first time the larva of C. nemorosa Neboiss. These descriptions increase the number of Caenota species to 7 and the number of associated and described larvae to 4. This paper also provides descriptions of features associated with the adult head capsule of all described species of Caenota. Each of the known species is considered, with illustrations and re-descriptions of these features given.


Subject(s)
Insecta/anatomy & histology , Insecta/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Ecosystem , Female , Insecta/growth & development , Larva/anatomy & histology , Larva/classification , Larva/growth & development , Male , Organ Size
7.
J Contam Hydrol ; 122(1-4): 53-62, 2011 Mar 25.
Article in English | MEDLINE | ID: mdl-21186066

ABSTRACT

The fate of nine trace organic compounds was evaluated during a 12month large-scale laboratory column experiment. The columns were packed with aquifer sediment and evaluated under natural aerobic and artificial anaerobic geochemical conditions, to assess the potential for natural attenuation of these compounds during aquifer passage associated with managed aquifer recharge (MAR). The nine trace organic compounds were bisphenol A (BPA), 17ß-estradiol (E2), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), carbamazepine, oxazepam, iohexol and iodipamide. In the low organic carbon content Spearwood sediment, all trace organics were non-retarded with retardation coefficients between 1.0 and 1.2, indicating that these compounds would travel at near groundwater velocities within the aquifer. The natural aerobic geochemical conditions provided a suitable environment for the rapid degradation for BPA, E2, iohexol (half life <1day). Lag-times for the start of degradation of these compounds ranged from <15 to 30days. While iodipamide was persistent under aerobic conditions, artificial reductive geochemical conditions promoted via the addition of ethanol, resulted in rapid degradation (half life <1days). Pharmaceuticals (carbamazepine and oxazepam) and disinfection by-products (NDMA and NMOR) did not degrade under either aerobic or anaerobic aquifer geochemical conditions (half life >50days). Field-based validation experiments with carbamazepine and oxazepam also showed no degradation. If persistent trace organics are present in recycled waters at concentrations in excess of their intended use, natural attenuation during aquifer passage alone may not result in extracted water meeting regulatory requirements. Additional pre treatment of the recycled water would therefore be required.


Subject(s)
Organic Chemicals/isolation & purification , Water Pollutants, Chemical/isolation & purification , Water Supply/analysis , Geologic Sediments/chemistry
8.
Water Res ; 44(5): 1471-81, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19939429

ABSTRACT

Water quality changes associated with the passage of aerobic reverse osmosis (RO) treated recycled water through a deep anaerobic pyritic aquifer system was evaluated in sediment-filled laboratory columns as part of a managed aquifer recharge (MAR) strategy. The fate of nine recycled water trace organic compounds along with potential negative water quality changes such as the release of metal(loid)s were investigated in large-scale columns over a period of 12 months. The anaerobic geochemical conditions provided a suitable environment for denitrification, and rapid (half-life <1-25 days) degradation of the endocrine disrupting compounds (bisphenol A, 17beta-estradiol, 17alpha-ethynylestradiol), and iodipamide. However, pharmaceuticals (carbamazepine and oxazepam), disinfection by-products (N-nitrosodimethylamine, N-nitrosomorpholine) and iohexol did not degrade rapidly (half-life > 100 days). High retardation coefficients (R) determined for many of the trace organics (R 13 to 67) would increase aquifer residence time and be beneficial for many of the slow degrading compounds. However, for the trace organics with low R values (1.1-2.6) and slow degradation rates (half-life > 100 days), such as N-nitrosodimethylamine, N-nitrosomorpholine and iohexol, substantial biodegradation during aquifer passage may not occur and additional investigations are required. Only minor transient increases in some metal(loid) concentrations were observed, as a result of either pyrite oxidation, mineral dissolution or pH induced metal desorption, followed by metal re-sorption downgradient in the oxygen depleted zone.


Subject(s)
Conservation of Natural Resources , Metals/isolation & purification , Organic Chemicals/isolation & purification , Water Pollutants, Chemical/isolation & purification , Water Supply/analysis , Adsorption , Anaerobiosis , Anions/analysis , Bromides/isolation & purification , Cations/analysis , Geologic Sediments/chemistry , Hydrogen-Ion Concentration , Manganese/isolation & purification , Nitrates/analysis , Oxygen/isolation & purification
9.
Article in English | MEDLINE | ID: mdl-19022771

ABSTRACT

Reconstitution assays have shown that mouse mammary stem cells reside within the mature mammary gland in vivo. Single cells could be prospectively isolated and shown to regenerate an entire mammary gland that exhibited full developmental capacity. The more recent identification of luminal progenitor populations has indicated that the mammary epithelium is organized in a hierarchical manner. Further definition of epithelial cell types in both mouse and human mammary glands will provide insight into the "cells of origin" in the different subtypes of breast cancer, as well as the nature of cancer-propagating cells. Here, we review the known characteristics of mammary stem and progenitor cells, their steroid receptor status, and the pathways that have thus far been implicated in regulating their self-renewal and differentiation.


Subject(s)
Mammary Glands, Animal/cytology , Stem Cells/cytology , Animals , Antigens, CD/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Differentiation , Cell Proliferation , Cell Separation , Epithelial Cells/cytology , Epithelial Cells/metabolism , Estrogen Receptor alpha/metabolism , Female , Humans , Mammary Glands, Animal/metabolism , Mammary Glands, Human/cytology , Mammary Glands, Human/metabolism , Mice , Models, Biological , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Receptors, Progesterone/metabolism , Stem Cells/metabolism
10.
Intern Med J ; 34(11): 615-20, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15546455

ABSTRACT

AIMS: To examine the level of agreement among observers regarding changes between serial images of bone metastases. METHODS: Thirty-five pairs of bone X-rays and 30 pairs of bone scans were selected from the files of patients with breast cancer involving the skeleton. All images in a pair were of the same site and had been taken at least 12 weeks apart. Thirteen radiologists and 14 nuclear medicine physicians examined the X-ray and bone scan pairs, respectively. Each assessed whether the changes between sequential films represented improvement, stability or worsening. Inter-observer agreement was analysed using the kappa statistic (kappa). RESULTS: There was only fair overall agreement among radiologists regarding changes between X-rays (kappa = 0.23), but there was substantial agreement among nuclear medicine physicians for bone scan assessments (kappa = 0.62). Neither the experience of the observers nor the time between images had a significant effect on agreement. For X-rays, agreement was poorer if the response category was 'improvement' and if the type of bone lesion was mixed lytic/sclerotic. CONCLUSIONS: Evaluation of serial X-rays is unreliable for determining the response of bone metastases. Scintigraphic evaluation has a higher internal validity for the determination of response, but it should not be used in isolation from other clinical data.


Subject(s)
Bone Neoplasms/secondary , Bone and Bones/diagnostic imaging , Breast Neoplasms/pathology , Aged , Bone Neoplasms/diagnostic imaging , Breast Neoplasms/diagnostic imaging , Female , Humans , Middle Aged , Observer Variation , Positron-Emission Tomography , Radiography/methods , Reproducibility of Results , X-Rays
11.
J Agric Food Chem ; 49(11): 5244-50, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11714311

ABSTRACT

A total of 570 lyophilised Brassica root and shoot tissue samples were hydrolyzed, and the liberated isothiocyanates (ITCs) were analyzed by gas chromatography-flame photometric detection (GC-FPD). Glucosinolates (GSLs) were extracted from samples of the same tissues and analyzed by high-performance liquid chromatography (HPLC). The concentrations of six GSLs/ITCs (2-propenyl, 3-butyl, 4-pentenyl, benzyl, 4-methylthiobutyl, and 2-phenylethyl) as determined by the two techniques were compared. In 79% of the samples, the concentration of GSLs in the tissues was greater than that of the ITCs released on hydrolysis. Several possible reasons for the difference are proposed, including the effect of tissue storage time, hydrolysis of GSLs may be less efficient than the GSL extraction procedure, or some of the ITCs formed reacted with plant proteins and amino acids in the sample and were therefore not detected in the extract. GSL concentration in plant tissues is used to estimate the biofumigation potential of the plant tissue, whereas the actual biofumigation effect is thought to be due to the ITCs formed by hydrolysis of the plant-based GSLs. The variation between ITC and GSL values therefore has implications for the assessment of the biofumigation potential of the plant tissue.


Subject(s)
Brassica/metabolism , Glucosinolates/metabolism , Isothiocyanates/metabolism , Chromatography, Gas , Chromatography, High Pressure Liquid , Hydrolysis , Pest Control, Biological
12.
Bull Entomol Res ; 90(4): 349-55, 2000 Aug.
Article in English | MEDLINE | ID: mdl-11020793

ABSTRACT

First instars of the soil-inhabiting whitefringed weevil, Naupactus leucoloma (Boheman), are a particularly good bioassay model for assessing volatile soil fumigants and biofumigants. Eggs are readily obtained and can be stored for long periods with larvae hatched on demand and the first instar is non-feeding, surviving without food or shelter. Longevity varies with temperature, but readily accommodates the period required to conduct bioassays without appreciable mortality of untreated controls. In vitro bioassays of pure methyl isothiocyanate, the active ingredient from metham sodium soil fumigant, and the less volatile 2-phenylethyl isothiocyanate, sensitively detected differences in toxicity and effects of temperature. Bioassay of volatiles emitted from hydrolysed tissue of various isothiocyanate-producing Brassica plants revealed widely varying toxicity effects, indicating that bioassays with N. leucoloma are a sensitive and relevant indicator of the potential of different plants for biofumigation of soil-borne pest organisms.


Subject(s)
Coleoptera , Isothiocyanates , Animals , Biological Assay , Longevity
13.
S Afr Med J ; 89(11): 1182-8, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10599300

ABSTRACT

OBJECTIVE: To evaluate a recently developed low-dose, large-field, direct digital X-ray scanning system for medical use. METHOD: Radiation dose, image quality, diagnostic capability and clinical utility of the unit were compared with those of conventional radiography. RESULTS: Radiation doses ranged from 3% to 5% of conventional radiographic values, and a mean of 1 line-pair per millimetre could be detected. Ease of use, anatomical coverage and tolerance to patient motion were advantages. However, image quality was inferior to that of conventional radiographs, with limited fine detail visibility and penetration. Only 67 of 156 (42.9%) pathological features seen on conventional radiographs were detected, including 13 of 41 fractures (31.7%) and 11 of 18 pneumothoraces (61.1%). CONCLUSION: Although image quality and diagnostic performance were not ideal, potential roles in triage, foreign body detection and possibly screening were promising. Radiographic factors may have affected sensitivity. This machine demonstrated useful attributes that may, with improvement, be beneficial in the imaging of trauma and other patients.


Subject(s)
Radiographic Image Enhancement/instrumentation , Adolescent , Adult , Aged , Child , Child, Preschool , Equipment Design/standards , Evaluation Studies as Topic , Humans , Infant , Infant, Newborn , Middle Aged , Radiation Dosage , Radiographic Image Enhancement/standards , Radiography, Abdominal/methods , Radiography, Abdominal/standards , Radiography, Thoracic/methods , Radiography, Thoracic/standards , Wounds, Gunshot/diagnostic imaging , Wounds, Stab/diagnostic imaging
14.
Curr Eye Res ; 18(2): 91-103, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10223652

ABSTRACT

PURPOSE: To determine the ocular pharmacokinetics of cyclosporin A after topical ophthalmic administration. METHODS: Radiolabled cyclosporin A in either a castor oil-in-water emulsion or a corn oil ointment was applied to the eyes of beagle dogs or albino rabbits using the following paradigms: (i) single doses of 0.2% emulsion to rabbits and dogs, (ii) single doses of 0.05%, 0.2%, or 0.4% emulsion to rabbits, (iii) multiple doses of 0.2% emulsion to dogs, (iv) single and multiple doses of 0.2% ointment to rabbits. The distribution of cyclosporin A was determined by measuring the distribution of radioactivity. RESULTS: After a single dose, cyclosporin A was rapidly absorbed into the conjunctiva (Cmax: dogs, 1490 ng/g; rabbits, 1340 ng/g) and cornea (Cmax: dogs, 311 ng/g; rabbits, 955 ng/g). High concentrations (>300 ng/g) could be detected in the cornea up to 96 hours post-dose. Lower concentrations were found in the intraocular tissues, and systemic absorption was minimal. After multiple doses, there was some accumulation in the cornea, lens, lacrimal gland, and iris-cilliary body, but limited accumulation in the conjunctiva and sclera. Ocular tissue concentrations of cyclosporin A increased with increasing dose concentration; proportionally in lacrimal gland and intraocular tissues; less than proportionally in conjunctiva and cornea. The pharmacokinetic profile of the cyclosporin A corn oil ointment was similar to that of the emulsion. CONCLUSIONS: Topical ophthalmic cyclosporin A penetrated into extraocular tissues at concentrations adequate for local immunomodulation while penetration into intraocular tissues was much less and absorption into the blood was minimal.


Subject(s)
Cyclosporine/pharmacokinetics , Eye/metabolism , Absorption , Administration, Topical , Animals , Ciliary Body/metabolism , Conjunctiva/metabolism , Cornea/metabolism , Cyclosporine/administration & dosage , Dogs , Dose-Response Relationship, Drug , Emulsions , Female , Iris/metabolism , Lacrimal Apparatus/metabolism , Lens, Crystalline/metabolism , Male , Ophthalmic Solutions/administration & dosage , Ophthalmic Solutions/pharmacokinetics , Rabbits , Sclera/metabolism , Tissue Distribution
15.
Aust N Z J Ment Health Nurs ; 8(4): 176-86, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10855092

ABSTRACT

Twenty key workers in a government agency evaluated the effectiveness of their interventions with culturally diverse clients. The sample comprised 73 clients, from 18 language groups. Forty per cent reported not having enough to do during the day and seventy-three per cent were visited regularly by their key workers. Ninety-two per cent were social security recipients. Though eighty-five per cent of key worker respondents perceived that the major needs of their clients were being met, twenty-one per cent felt they had insufficient contact with clients. The cultural appropriateness of interventions and client's accessibility to services were not confirmed in anecdotal comments.


Subject(s)
Attitude of Health Personnel , Case Management/organization & administration , Communication Barriers , Community Mental Health Services/organization & administration , Cultural Diversity , Ethnicity/statistics & numerical data , Needs Assessment/organization & administration , Public Health Practice , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , South Australia , Surveys and Questionnaires
17.
J Pharm Sci ; 85(4): 415-8, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8901080

ABSTRACT

This study was designed to examine the effect of benzalkonium chloride/ethylenediaminetetraacetic acid (BAK/EDTA) on the ocular bioavailability (Focular) of ketorolac tromethamine after ocular instillation to normal and de-epithelialized corneas of rabbits both in vitro and in vivo. The in vitro Focular of the formulations was measured in flow-through perfusion chambers. For in vivo studies, a 35 microL dose of 0.5% ketorolac tromethamine with or without BAK/EDTA was instilled into rabbit eyes with intact or de-epithelialized corneas. At 0.5, 1, 2, 4, 6, and 8 h postdose, rabbits were euthanized, and the corneas and aqueous humor were collected from both eyes. The ketorolac concentrations from both in vivo and in vitro samples were quantified by reversed-phase high-performance liquid chromatography. The in vitro study results indicated that BAK/EDTA statistically significantly increased the Focular of ketorolac through de-epithelialized corneas but not through intact corneas. The in vivo study results showed that BAK/EDTA had no effect on the Focular of ketorolac in rabbits with intact corneas, based on the values of the area under the aqueous humor concentration versus time curves (AUC0-6h) of ketorolac. As expected, de-epithelialization of the corneas produced a faster and greater ocular absorption of ketorolac as evidenced by the smaller Tmax and larger AUC values compared to those for the intact corneas in vivo. However, BAK/EDTA decreased the ocular absorption of ketorolac in rabbits with de-epithelialized corneas. The half-lives (t 1/2) of ketorolac in corneal tissue and aqueous humor were longer in rabbits with intact corneas than those in rabbits with de-epithelialized corneas. In conclusion, the in vivo Focular of ketorolac was not altered by BAK/EDTA in rabbits with intact corneas, but it was decreased by BAK/EDTA in rabbits with de-epithelialized corneas. Therefore, the formulation with ketorolac alone may be better as a post-operative ocular analgesic.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Benzalkonium Compounds/pharmacology , Cornea/drug effects , Edetic Acid/pharmacology , Tolmetin/analogs & derivatives , Tromethamine/analogs & derivatives , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Biological Availability , Cornea/metabolism , Drug Carriers , Endothelium/drug effects , Endothelium/metabolism , Female , Half-Life , Ketorolac Tromethamine , Ophthalmic Solutions , Rabbits , Tolmetin/administration & dosage , Tolmetin/pharmacokinetics , Tromethamine/administration & dosage , Tromethamine/pharmacokinetics
18.
Drug Metab Dispos ; 23(7): 708-12, 1995 Jul.
Article in English | MEDLINE | ID: mdl-7587958

ABSTRACT

Brimonidine is a potent ocular hypotensive drug. The ocular pharmacokinetics of 14C-brimonidine in albino and pigmented rabbits were compared after ocular instillation of a 35-microliters drop of a 0.5% 14C-brimonidine solution. Ocular drug and metabolite concentrations were measured as total radioactivity and by a selective HPLC method. Rapid ocular absorption resulted in peak drug concentrations in aqueous humor of 2.16 +/- 0.75 micrograms/ml (mean +/- SD) and 1.52 +/- 0.38 micrograms/ml at 0.67 hr postdosing in albino and pigmented rabbits, respectively. Drug elimination from aqueous humor was rapid initially with a half-life of 1 hr in rabbits, followed by a slower decline phase in pigmented rabbits. Radioactivity concentration in iris-ciliary body of albino rabbit reached a peak of 5.04 micrograms-eq/g at 40 minutes and declined to 0.10 micrograms-eq/g at 6 hr postdosing with a half-life of 1 hr. The radioactivity concentrations in pigmented iris-ciliary body rose to a peak of 20.1 micrograms-eq/g at 1.5 hr and stayed relatively steady for at least 4 hr before declining slowly to 0.43 micrograms-eq/g 90 days postdose. The terminal half-life of brimonidine in pigmented iris-ciliary body was 160 hr. Three metabolites were detected in the conjuctiva and iris-ciliary body, and brimonidine was the major drug-related substance in aqueous humor and iris-ciliary body. The results indicate that brimonidine is absorbed rapidly into rabbit eyes, metabolized in ocular tissues, and has significant affinity for melanin-containing tissues.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Adrenergic alpha-Agonists/pharmacokinetics , Eye/metabolism , Quinoxalines/pharmacokinetics , Adrenergic alpha-Agonists/blood , Adrenergic alpha-Agonists/metabolism , Albinism, Oculocutaneous/metabolism , Animals , Brimonidine Tartrate , Carbon Radioisotopes , Chromatography, High Pressure Liquid , Female , Ophthalmic Solutions , Pigment Epithelium of Eye/metabolism , Quinoxalines/blood , Quinoxalines/metabolism , Rabbits
19.
J Ocul Pharmacol Ther ; 11(4): 489-502, 1995.
Article in English | MEDLINE | ID: mdl-8574812

ABSTRACT

The potential effects of anti-glaucoma drugs, such as levobunolol and timolol, on blood flow in the posterior segment of the eye are of great interest in terms of changes in optic nerve head perfusion and prevention of visual field loss. These effects are related to the rate and extent of their absorption into the site of action. In this study, the concentrations of timolol and levobunolol in the aqueous humor, iris-ciliary body, vitreous humor, choroid-retina, and optic nerve were compared following instillation of a single drop of 0.5% ophthalmic solutions into albino rabbit eyes. Tissue drug and metabolite concentrations were measured by liquid chromatography-mass spectrometry. Dihydrobunolol (DHB) is an equipotent metabolite of levobunolol. In the anterior segment of the eye, levobunolol plus DHB concentrations were higher than timolol concentrations in aqueous humor and were comparable to those of timolol in iris-ciliary body. However, in the choroid-retina and optic nerve, timolol concentrations were greater than those of levobunolol plus DHB. Overall, the study demonstrates comparable concentrations of levobunolol and timolol in the anterior section of the eye. The low availability of levobunolol in the posterior segment as compared to timolol may be a key advantage for levobunolol in producing less adverse effect on blood flow in the choroid-retina and optic nerve.


Subject(s)
Adrenergic beta-Antagonists/pharmacokinetics , Eye/metabolism , Levobunolol/pharmacokinetics , Optic Nerve/metabolism , Timolol/pharmacokinetics , Absorption , Animals , Aqueous Humor/metabolism , Biological Availability , Choroid/metabolism , Ciliary Body/metabolism , Female , Gas Chromatography-Mass Spectrometry , Half-Life , Iris/metabolism , Levobunolol/analogs & derivatives , Ophthalmic Solutions , Rabbits , Retina/metabolism , Tissue Distribution , Vitreous Body/metabolism
20.
Mod Pathol ; 5(6): 603-6, 1992 Nov.
Article in English | MEDLINE | ID: mdl-1369793

ABSTRACT

Malignant transformation of human cells is associated with morphological and biochemical alterations. We have studied the distribution and pattern of staining of HMFG2 (human milk fat globulin) in normal breast, benign breast lesions, and 137 primary and metastatic breast carcinomas. Immunohistochemical staining was performed with an antibody to HMFG2 using the indirect peroxidase technique. Three patterns of staining were noted: 1) secretion and luminal staining (in normal breast, most benign breast lesions and some breast carcinomas); 2) plasma membrane staining (in breast carcinomas); 3) intracytoplasmic staining (in breast carcinomas). Immunoelectron microscopy was also performed on normal breast, infiltrating duct, and lobular carcinomas. Immunoelectron microscopy showed localization of the gold particles on the electron dense granules of the HMFG2 protein. These were localized along the surface of the extracytoplasmic lumina in normal breast ducts/acini and breast carcinomas, whereas localization was also noted within the intracytoplasmic lumina in cancer cells only. These results show that there is altered localization of milk fat globulin in breast cancer cells associated with membrane internalization and formation of intracytoplasmic lumina. This contributes to the understanding of the phenotypic alterations associated with malignant transformation in breast cancer.


Subject(s)
Breast Neoplasms/metabolism , Carcinoma/metabolism , Membrane Glycoproteins/metabolism , Mucins/metabolism , Subcellular Fractions/metabolism , Breast Diseases/metabolism , Breast Diseases/pathology , Breast Neoplasms/pathology , Carcinoma/pathology , Humans , Immunohistochemistry , Microscopy, Electron , Microscopy, Immunoelectron , Mucin-1 , Neoplasm Proteins/metabolism , Reference Values
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