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1.
Ann Oncol ; 31(9): 1223-1230, 2020 09.
Article in English | MEDLINE | ID: mdl-32464281

ABSTRACT

BACKGROUND: Neratinib is an irreversible pan-HER tyrosine kinase inhibitor approved for extended adjuvant treatment in early-stage HER2-positive breast cancer based on the phase III ExteNET study. In that trial, in which no antidiarrheal prophylaxis was mandated, grade 3 diarrhea was observed in 40% of patients and 17% discontinued due to diarrhea. The international, open-label, sequential-cohort, phase II CONTROL study is investigating several strategies to improve tolerability. PATIENTS AND METHODS: Patients who completed trastuzumab-based adjuvant therapy received neratinib 240 mg/day for 1 year plus loperamide prophylaxis (days 1-28 or 1-56). Sequential cohorts evaluated additional budesonide or colestipol prophylaxis (days 1-28) and neratinib dose escalation (DE; ongoing). The primary end point was the incidence of grade ≥3 diarrhea. RESULTS: Final data for loperamide (L; n = 137), budesonide + loperamide (BL; n = 64), colestipol + loperamide (CL; n = 136), and colestipol + as-needed loperamide (CL-PRN; n = 104) cohorts, and interim data for DE (n = 60; completed ≥six cycles or discontinued; median duration 11 months) are available. No grade 4 diarrhea was observed. Grade 3 diarrhea rates were lower than ExteNET in all cohorts and lowest in DE (L 31%, BL 28%, CL 21%, CL-PRN 32%, DE 15%). Median number of grade 3 diarrhea episodes was one; median duration per grade 3 episode was 1.0-2.0 days across cohorts. Most grade 3 diarrhea and diarrhea-related discontinuations occurred in month 1. Diarrhea-related discontinuations were lowest in DE (L 20%, BL 8%, CL 4%, CL-PRN 8%, DE 3%). Decreases in health-related quality of life did not cross the clinically important threshold. CONCLUSIONS: Neratinib tolerability was improved with preemptive prophylaxis or DE, which reduced the rate, severity, and duration of neratinib-associated grade ≥3 diarrhea compared with ExteNET. Lower diarrhea-related treatment discontinuations in multiple cohorts indicate that proactive management can allow patients to stay on neratinib for the recommended time period. CLINICALTRIALS.GOV: NCT02400476.


Subject(s)
Breast Neoplasms , Quinolines , Receptor, ErbB-2 , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/drug therapy , Humans , Quality of Life , Quinolines/therapeutic use , Receptor, ErbB-2/genetics , Trastuzumab/therapeutic use
2.
Sci Rep ; 8(1): 17314, 2018 11 23.
Article in English | MEDLINE | ID: mdl-30470763

ABSTRACT

Mycobacteriosis is an emerging zoonotic disease of domestic cats and timely, accurate diagnosis is currently challenging. To identify differential cytokine/chemokine concentrations in serum/plasma of cats, which could be diagnostic biomarkers of infection we analysed plasma/serum from 116 mycobacteria-infected cats, 16 healthy controls and six cats hospitalised for unrelated reasons was analysed using the Milliplex MAP Feline Cytokine Magnetic Bead multiplex assay. Three cytokines; sFAS, IL-13 and IL-4 were reduced while seven; GM-CSF, IL-2, PDGF-BB, IL-8, KC, RANTES and TNF-α were elevated in mycobacteria-infected cats compared to healthy controls. However, IL-8 and KC concentrations were not significantly different from cats hospitalised for other reasons. Elevations in TNF-α and PDGF-BB may have potential to identify M. bovis and M. microti infected cats specifically while GM-CSF, IL-2 and FLT3L were increased in MTBC infected cats. This study demonstrates potential use of feline tuberculosis as a spontaneously occurring model of this significant human disease. Cytokine profiling has clear diagnostic potential for mycobacteriosis of cats and could be used discriminate tuberculous from non-tuberculous disease to rapidly inform on zoonotic risk. Future work should focus on the in-field utility of these findings to establish diagnostic sensitivity and specificity of these markers.


Subject(s)
Biomarkers/blood , Cat Diseases/diagnosis , Chemokines/blood , Cytokines/blood , Mycobacterium Infections/veterinary , Mycobacterium/isolation & purification , Animals , Cat Diseases/blood , Cat Diseases/microbiology , Cats , Mycobacterium Infections/blood , Mycobacterium Infections/diagnosis , Mycobacterium Infections/microbiology
3.
Diabetes Metab ; 43(3): 240-247, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28131740

ABSTRACT

AIMS: Obstructive sleep apnea syndrome (OSAS) is associated with increased cardiovascular risk and diabetes independent of obesity. We investigated whether adipose tissue dysfunction is exacerbated due to increased tissue hypoxia. METHODS: Adipose tissue (AT) oxygenation was measured with a Clarke-type electrode (pATO2) in 16 men with OSAS before and after 4 months of continuous positive airway pressure therapy (CPAP) and in BMI-matched controls. Oxygenation was simultaneously monitored in arterial blood by pulse oximetry (SaO2); mixed blood in AT microcirculation by reflectance spectroscopy (SATO2) along with blood flow. Markers of hypoxia, adipo- and angiogenesis, inflammation and fibrosis were analysed in AT and serum. RESULTS: OSAS subjects were more insulin resistant. Despite lower arterial SaO2 (95.4±1.3% vs. 97.1±1.6%, P=0.013) in subjects with OSAS, there was no difference in the oxygen content of AT microcirculation (61.6±18.4 vs. 72.2±7.0%, P=0.07) or pATO2 (49.2±7.5 vs. 50.4±14.7mmHg, P=0.83) between groups. Resting AT blood flow was higher in OSAS compared to controls (108.5±22.7 vs. 78.9±24.9au, P<0.005) and strongly associated with inflammation markers IL-6 and MCP-1. AT of OSAS subjects showed increased inflammation (TNFA P=0.049) and fibrosis (COL3A1 P=0.02), a trend of higher HIF1A expression (P=0.06) and reduced adipogenesis (PPARG P=0.006). After CPAP, only expression of the lipid deposition marker LPL increased (30%, P=0.047). CONCLUSIONS: Adipose tissue of awake OSAS subjects appears no more hypoxic than adipose tissue of BMI-matched controls despite daytime hypoxaemia. Increased adipose tissue blood flow may be explained by an increased inflammatory response. We observe features of adipose dysfunction in subjects with OSAS, which attribute to increased cardiometabolic risk associated with this condition.


Subject(s)
Adipose Tissue/physiopathology , Hypoxia/physiopathology , Obesity/physiopathology , Sleep Apnea, Obstructive/physiopathology , Adipose Tissue/metabolism , Aged , Case-Control Studies , Humans , Hypoxia/metabolism , Insulin Resistance , Male , Middle Aged , Obesity/metabolism , Oxygen/analysis , Oxygen/metabolism , Sleep Apnea, Obstructive/metabolism
5.
Diabet Med ; 19 Suppl 4: 73-8, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12121342

ABSTRACT

UNLABELLED: AIMS OF THE AUDIT COMMISSION: The Audit Commission has a statutory duty to promote the best use of public money. It does this through value for money studies, such as that reported in Testing Times[1]. This work has been followed with a review of innovative practice in commissioning. These initiatives aim to support the implementation of the diabetes national service framework. The Audit Commission also appoints external auditors to NHS organizations who assess probity and value for money in the NHS; the latter by applying national studies locally and by carrying out local studies. METHODS: Research for Testing Times consisted of structured visits to nine acute trusts, a telephone survey of 26 health authorities and a postal survey of 1400 people with diabetes and 250 general practitioners. Local audits used a subset of the original research tools. Case studies were identified through a cascade approach to contacts established during Testing Times and through self-nomination. RESULTS: Rising numbers of people with diabetes are placing increasing pressure on hospital services. Some health authorities and primary care organizations have reviewed patterns of service provision in the light of the increasing demands. These reviews show wide variations in patterns of routine care. In addition, there is a widespread lack of data on the delivery of structured care to people with diabetes. People with diabetes report delays in gaining access to services, and insufficient time with staff. There are insufficient arrangements in place for providing information and learning opportunities to support self-management. CONCLUSION: As the number of people with diabetes continues to rise, the potential for providing more care in a primary care setting needs to be explored. This will enable specialist services to focus more effectively on those with the most complex needs.


Subject(s)
Diabetes Mellitus/therapy , Family Practice/standards , Medical Audit , Primary Health Care/standards , Health Care Costs , Humans , State Medicine/standards , United Kingdom
6.
J Psychiatry Neurosci ; 24(4): 338-40, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10516801

ABSTRACT

OBJECTIVE: To determine the incidence of deep venous thrombosis (DVT) in patients with Parkinson disease. DESIGN: Prospective study. SETTING: Outpatient neurology clinic. PATIENTS: Eighty-one patients with Parkinson disease. OUTCOME MEASURES: Duplex ultrasonographic scans consisting of M mode images and compression images, Doppler flow assessment and augmentation of flow assessment. RESULTS: Four patients had leg DVT; in 3 of the patients the thrombi were in calf veins, whereas in 1 patient the thrombosis was in the superficial femoral vein. Of the patients with DVT, 1 (1.23%) had stage 2 Parkinson disease, 1 (1.23%) had stage 2.5, and the other 2 (2.46%) had stage 4. CONCLUSIONS: There was no statistically significant difference in the incidence of DVT among patients who were more severely disabled by Parkinson disease. However, an overall incidence of DVT of 4.9% in a group of asymptomatic patients is clinically meaningful, suggesting that patients with Parkinson disease are at risk for asymptomatic leg DVT.


Subject(s)
Parkinson Disease/complications , Venous Thrombosis/complications , Venous Thrombosis/diagnostic imaging , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Severity of Illness Index , Ultrasonography, Doppler/methods , Venous Thrombosis/epidemiology
7.
J Urol ; 162(3 Pt 1): 832-40, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10458391

ABSTRACT

PURPOSE: Loss of bladder compliance from hypercontractility and fibrosis may represent an injury response to excessive intravesical pressure. Together, interactions between cell and extracellular matrix components regulate cell response to injury and extracellular matrix remodeling. The receptor for hyaluronic acid mediated motility (RHAMM) is a recently described hyaluronic acid binding protein known to influence multiple types of cell extracellular matrix interaction in development, injury and cancer. We evaluate the role of RHAMM in mediating early events in bladder stretch injury. MATERIALS AND METHODS: An acute stretch injury model was used. The rat bladder was injured by hydrodistention inducing gross hematuria. Tissues were analyzed for temporal and spatial expression of RHAMM in the mucosa and detrusor regions by immunostaining, western and reverse transcriptase polymerase chain reaction analyses. The contractile activity of smooth muscle cell primary cultures was analyzed using a gel contraction assay in the presence of peptide fragments known to block RHAMM function. RESULTS: Acute hydrodistention caused immediate and significant injury to the bladder, with fracturing of smooth muscle cell bundles, edema and hemorrhage. RHAMM immunolocalized to the mucosa and detrusor within 2 hours of injury, peaking by 5 to 10 hours. A shift from low molecular weight (55 kD.) to high (120 kD.) receptor isoforms was prominent during the peak expression period noted by immunolocalization. RHAMM messenger ribonucleic acid increased only slightly (40%) by 5 hours after injury. Smooth muscle cell primary cultures actively initiated and maintained the contraction of collagen gels by more than 75% of baseline in vitro. Blocking RHAMM function significantly inhibited the ability to less than 25% of smooth muscle cells to contract the gels in vitro. CONCLUSIONS: Increased expression of RHAMM is an early event precipitated by stretch injury to the bladder. Since extracellular matrix hyaluronic acid is found early in tissue repair responses, its receptor RHAMM may be mediating initial bladder responses to stretch injury, some of which (contraction) may be experimentally blocked in vitro. Since the receptor directly regulates protein kinase signaling which in turn mediates smooth muscle cell contraction and collagen synthesis, further studies of RHAMM function in bladder pathology are warranted.


Subject(s)
Extracellular Matrix Proteins/physiology , Hyaluronan Receptors/physiology , Hyaluronic Acid/physiology , Muscle Contraction/physiology , Muscle, Smooth/cytology , Muscle, Smooth/injuries , Urinary Bladder/physiology , Animals , Cell Division , Cells, Cultured , Female , Muscle, Smooth/physiopathology , Rats , Rats, Sprague-Dawley
8.
Mov Disord ; 12(5): 747-51, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9380059

ABSTRACT

Multicase families are frequently utilized in studies of movement disorders (MDs). We report families with two or more MD cases seen at the Movement Disorder Clinic, Saskatoon (MDCS). In 30% of the MD probands, there was either a history or documentation of at least one secondary MD case in the family. Only those MD cases that were seen at the MDCS were considered in this study. A total of 56 probands and 77 secondary MD cases were seen at the MDCS between 1968 and 1996. In 24 (31.2%) of the secondary cases, the diagnosis was different from that in the proband. In 46 families (82%), only one secondary case was seen, and the diagnosis was concordant with the proband in 71.7%. In the remaining 10 families with two or more secondary cases, the diagnosis was concordant in 64.5% of cases. The largest subgroup was Parkinson's disease (PD)--40 probands and 53 secondary cases. of these secondary cases, 73.6% had PD. The concordance rate was 91% in essential tremor, but only 12.5% if the proband had essential tremor + parkinsonism. Considering that a large proportion of secondary cases have a diagnosis discordant with the proband, we recommend that, whenever possible, MD diagnosis in secondary cases be based on clinical assessment.


Subject(s)
Family Health , Genetic Variation , Movement Disorders/genetics , Age of Onset , Aged , Disease Progression , Female , Humans , Male , Middle Aged , Movement Disorders/drug therapy , Parkinson Disease/drug therapy , Parkinson Disease/genetics , Retrospective Studies , Saskatchewan , Spinocerebellar Degenerations/drug therapy , Spinocerebellar Degenerations/genetics , Supranuclear Palsy, Progressive/drug therapy , Supranuclear Palsy, Progressive/genetics , Tremor/drug therapy , Tremor/genetics
9.
J Pediatr ; 121(6): 980-3, 1992 Dec.
Article in English | MEDLINE | ID: mdl-1447671

ABSTRACT

Four neonates had resolution of peripheral tissue ischemia after the application of 2% nitroglycerin ointment. A dosage of 4 mm nitroglycerin ointment per kilogram of body weight was applied to two patients with ischemia caused by vasospasm from indwelling radial artery catheterization and to two patients with ischemia resulting from dopamine extravasation. No adverse effects were noted except mild episodes of decreased blood pressure in two of the patients.


Subject(s)
Hand/blood supply , Ischemia/drug therapy , Nitroglycerin/administration & dosage , Administration, Topical , Catheters, Indwelling/adverse effects , Dopamine/administration & dosage , Dopamine/adverse effects , Extravasation of Diagnostic and Therapeutic Materials/complications , Humans , Infant , Infant, Newborn , Infant, Premature , Ischemia/etiology , Ointments
10.
Am J Pathol ; 141(6): 1381-96, 1992 Dec.
Article in English | MEDLINE | ID: mdl-1281619

ABSTRACT

Progressive renal fibrosis is considered to be the final common pathway leading to chronic renal insufficiency. In this study, the authors examined some of the cellular and molecular mechanisms regulating the renal accumulation of extracellular matrix (ECM) proteins using rats with puromycin amino-nucleoside (PAN) nephrosis as an acute model system. Puromycin aminonucleoside rats developed reversible nephrotic syndrome accompanied by an interstitial infiltrate of monocytes. The number of interstitial fibroblasts expressing ST4 antigen did not increase. During the first 4 days, steady-state mRNA levels for all genes examined remained at or below control levels. At 1 week, nephrotic syndrome and interstitial inflammation were established, and a period of renal cell proliferation occurred, identified by increased histone mRNA levels and localized by tritiated thymine autoradiography to tubular epithelial cells and occasional interstitial cells. Transforming growth factor-beta (TGF-beta) steady-state mRNA levels were increased eightfold, but returned to control levels by 3 weeks. At week 1, there was a 10- to 20-fold increase in kidney steady-state mRNA levels for genes encoding interstitial matrix proteins collagen I and fibronectin and basement membrane collagen IV. By in situ hybridization, alpha 1(I) procollagen mRNA was localized to interstitial cells. Immunofluorescence microscopy demonstrated focal accumulation of ECM proteins in the tubulointerstitial compartment at 2 and 3 weeks, but by 6 weeks, kidney immunohistology was normal again. Steady-state mRNA levels for the matrix degrading metalloproteinase stromelysin remained at control values, whereas the levels for interstitial collagenase were normal at week 1 and increased twofold to threefold at 2 and 3 weeks. Steady-state mRNA levels for the tissue inhibitor of metalloproteinases (TIMP) increased fivefold at 1 week and returned to baseline values over the next 2 weeks. The results of this study suggest that tubulointerstitial ECM accumulation occurs in rats with acute PAN nephrosis because of the activation of genes encoding several matrix proteins and inhibition of matrix degradation mediated by TIMP. These events are reversed during the phase of recovery from nephrotic syndrome. Increased mRNA levels for TGF-beta, possibly originating from inflammatory interstitial monocytes, are likely to be one of the mediators of the molecular events observed.


Subject(s)
Extracellular Matrix Proteins/metabolism , Extracellular Matrix/metabolism , Kidney/metabolism , Nephrosis/chemically induced , Nephrosis/metabolism , Puromycin Aminonucleoside/adverse effects , Animals , Basement Membrane/chemistry , Basement Membrane/metabolism , Basement Membrane/ultrastructure , Blotting, Northern , Cell Division , Collagen/analysis , Collagen/genetics , Collagen/metabolism , DNA/analysis , DNA/genetics , Disease Models, Animal , Extracellular Matrix/chemistry , Extracellular Matrix/ultrastructure , Extracellular Matrix Proteins/analysis , Extracellular Matrix Proteins/genetics , Female , Fibronectins/analysis , Fibronectins/genetics , Fibronectins/metabolism , Fluorescent Antibody Technique , Gene Expression , In Situ Hybridization , Injections, Intraperitoneal , Kidney/pathology , Kidney/ultrastructure , Metalloendopeptidases/genetics , Metalloendopeptidases/metabolism , Nephrosis/pathology , Puromycin Aminonucleoside/administration & dosage , RNA/analysis , RNA/genetics , RNA, Messenger/analysis , RNA, Messenger/genetics , Rats , Rats, Inbred Lew , Thymidine/metabolism , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/metabolism
12.
Kidney Int ; 40(6): 1020-31, 1991 Dec.
Article in English | MEDLINE | ID: mdl-1762303

ABSTRACT

A cellular and molecular approach was used to gain new insight into the pathogenesis of interstitial fibrosis in chronic purine aminonucleoside nephrosis (PAN) nephrosis. Thirty experimental rats (PAN rats) were given 15 mg/100 g body wt of i.p. PAN at time 0, followed by 4.3 mg/100 g body wt i.p. on days 20, 27 and 34; 25 control rats received i.p. saline at the same time intervals. All rats had a right unilateral nephrectomy within the first four days. Groups of control and PAN rats were killed at 21, 37, 52, 72 and 91 days. Renal sections were studied by immunofluorescence to quantitate interstitial macrophages, T lymphocytes and fibroblasts, and to characterize the deposition of the extracellular matrix (ECM) proteins (collagens I, III and IV, fibronectin and laminin) and the tissue inhibitor of the metalloproteinases (TIMP). Steady state concentrations of mRNA from the whole kidney for these ECM proteins, the metalloproteinases, TIMP, and transforming growth factor beta (TGF-beta 1) were quantitated by Northern blot analysis. Significant increases in the number of interstitial macrophages and T lymphocytes were found in the PAN rat groups compared to that in controls. All ECM proteins examined were quantitatively increased in the tubulo-interstitium of PAN rats. The pattern of distribution of some ECM proteins was also modified in experimental animals. TIMP was increased in the interstitium of PAN rats; at later times, TIMP was most prominent in sclerotic regions of the glomeruli and in tubular protein droplets. Northern blot analysis revealed increased steady-state mRNA levels for components of each of the ECM proteins, no change for the metalloproteinases--stromelysin or collagenase--and a marked increase for TIMP and TGF-beta 1 in PAN animals. The results of this study suggest that the diffuse interstitial fibrosis found in chronic PAN nephrosis results from both increased production of ECM proteins and decreased matrix degradation.


Subject(s)
Nephrosis/etiology , Albuminuria/etiology , Animals , Chronic Disease , Creatinine/blood , Disease Models, Animal , Extracellular Matrix Proteins/genetics , Extracellular Matrix Proteins/metabolism , Female , Fibrosis , Gene Expression , Glycoproteins/genetics , Glycoproteins/metabolism , Macrophages/metabolism , Macrophages/pathology , Metalloendopeptidases/antagonists & inhibitors , Metalloendopeptidases/genetics , Nephrosis/metabolism , Nephrosis/pathology , Puromycin Aminonucleoside , Rats , Rats, Inbred Lew , Tissue Inhibitor of Metalloproteinases , Transforming Growth Factor beta/genetics
13.
Am J Pathol ; 138(5): 1111-23, 1991 May.
Article in English | MEDLINE | ID: mdl-2024704

ABSTRACT

The relationship between tubulointerstitial nephritis and proteinuria was characterized in experimental nephrosis in rats. In one group, proteinuria induced by aminonucleoside of puromycin (PAN) was reduced by using an 8% protein diet and adding the angiotensin I-converting enzyme (ACE) inhibitor enalapril to the drinking water. Two control groups were injected with saline and PAN, respectively, and fed a 27% protein diet. The first group had significantly reduced albuminuria and a definite attenuation of tubular cell injury. There was a strong positive correlation between the number of interstitial macrophages and albuminuria. The beneficial effect was reproduced by dietary-protein restriction alone, whereas ACE inhibition alone had an insignificant effect on the degree of proteinuria. Depletion of circulating T lymphocytes in one group of nephrotic rats eliminated interstitial lymphocytes but did not affect interstitial macrophage influx. Inhibition of the in situ proliferation of resident interstitial macrophages by unilateral kidney irradiation failed to change the intensity of the macrophage infiltration. Treatment of rats with sodium maleate produced proximal tubular cell toxicity but interstitial inflammation did not develop, suggesting that the latter is not a nonspecific response to tubular injury. These studies demonstrate a strong relationship between tubulointerstitial nephritis and the severity of proteinuria in experimental nephrosis.


Subject(s)
Nephritis, Interstitial/complications , Nephrotic Syndrome/complications , Proteinuria/complications , Acute Disease , Administration, Oral , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Animals , Cell Division/drug effects , Dietary Proteins/administration & dosage , Dietary Proteins/therapeutic use , Disease Models, Animal , Enalapril/administration & dosage , Enalapril/therapeutic use , Female , Kidney/drug effects , Kidney/radiation effects , Lymphocyte Depletion , Macrophages/drug effects , Macrophages/radiation effects , Maleates/toxicity , Nephritis, Interstitial/drug therapy , Nephritis, Interstitial/pathology , Nephrotic Syndrome/chemically induced , Nephrotic Syndrome/pathology , Proteinuria/drug therapy , Proteinuria/pathology , Puromycin/adverse effects , Rats , Rats, Inbred Lew
14.
Clin Immunol Immunopathol ; 57(3): 441-58, 1990 Dec.
Article in English | MEDLINE | ID: mdl-2245521

ABSTRACT

Although circulating phagocytic cells are important mediators of glomerular injury, their recruitment mechanisms are not completely understood. In this study, the intraglomerular trafficking of leukocytes was characterized in a rat model of acute glomerular injury induced by nephrotoxic serum (NTS). Polymorphonuclear (PMN) cells infiltrated, then disappeared rapidly, reaching a peak at 2 hr. By 6 hr the PMN migration had almost reversed but small numbers persisted until Day 7. The monocyte influx began almost simultaneously but was of lesser magnitude. However, the number of ED-1+ monocytes increased progressively from 60 min to reach a plateau by Day 2 and persisted to the end of the study (Day 28). Quantitation of intraglomerular Ia+ cells suggested in situ activation of monocytes within the glomeruli. Increased Ia+ cells were first evident on Day 2. By Day 5, 80% of the intraglomerular macrophages were Ia+. Complement depletion with cobra venom factor abrogated early albuminuria, delayed the initial PMN influx, but failed to attenuate monocyte migration. T lymphocytes appeared briefly between 10 min and 2 hr. In vitro proliferation study failed to demonstrate lymphocyte sensitization to glomerular basement membrane (GBM) antigens. A unique population of cells (OX19 OX8+), possibly representing natural killer cells, was present from Day 1 to Day 14. During the secondary wave of proteinuria (autologous phase), all leukocytes had disappeared except for macrophages and a small number of OX19-, OX8+ cells. A complex intraglomerular migration of leukocytes was triggered by the binding of nephrotoxic antibodies to GBM antigens. We speculate that this cascade involves several cell-to-cell interactions necessary for the full expression of glomerular injury.


Subject(s)
Kidney Glomerulus/immunology , Leukocytes/immunology , Nephritis/physiopathology , Animals , Basement Membrane/immunology , Cell Division , Cell Movement , Complement System Proteins/physiology , Concanavalin A/pharmacology , Disease Models, Animal , Fluorescent Antibody Technique , Kidney Cortex/immunology , Kidney Cortex/pathology , Male , Monocytes/physiology , Neutrophils/physiology , Phagocytes/physiology , Proteinuria , Rats , Rats, Inbred Lew
15.
Bull Med Libr Assoc ; 78(4): 412, 1990 Oct.
Article in English | MEDLINE | ID: mdl-16017974
17.
J Gen Physiol ; 73(4): 493-514, 1979 Apr.
Article in English | MEDLINE | ID: mdl-448327

ABSTRACT

Experiments were designed to determine whether band 3, the anion transport protein of the red cell membrane, contains a mobile element that acts as a carrier to move the anions across a permeability barrier. The transport site-specific, nonpenetrating irreversible inhibitor 4,4'-diisothiocyano-2,2'-stilbene disulfonate (DIDS) was found to be effective only when applied extracellularly. It was used to sequester transport sites on the extracellular side of the membrane in intact cells. The membranes were then coverted into inside-out vesicles. The number of anion transport sites available on the cytoplasmic side of the vesicle membranes was then estimated by measuring the binding of N-(-4-azido-2-nitrophenyl)-2-aminoethyl-sulfonate (NAP-taurine), a photoreactive probe. Pretreatment with DIDS from the extracullular side substantially reduced the binding of NAP-taurine at the cytoplasmic side. Since NAP-taurine does not appear to penetrate into the intravesicular (normally extracellular) space, a transmembrane effect is apparently involved. About 70% of the DIDS-sensitive NAP-taurine binding sites are located in band 3, with the remainder largely in a lower molecular weight (band 4) region. A similar pattern of reduction in NAP-taurine binding is produced by high concentrations of Cl-, but this anion has little or no effect in vesicles from cells pretreated with DIDS. Thus the DIDS-modulated sites seem to be capable of binding either NAP-taurine or Cl. It is suggested that band 3 contains a mobile transport element that can be recruited to the extracellular surface by DIDS, thus becoming unavailable to NAP-taurine at the cytoplasmic face of the membrane. The results are consistent with a model of carrier-mediated transport in which the movement of the transport site is associated with a local conformational change in band 3 protein.


Subject(s)
Carrier Proteins/metabolism , Cell Membrane Permeability/drug effects , Erythrocyte Membrane/physiology , Erythrocytes/physiology , Stilbenes/pharmacology , Binding Sites , Chlorides/pharmacology , Erythrocyte Membrane/drug effects , Humans , Nitrobenzenes/metabolism , Protein Conformation , Taurine/analogs & derivatives , Taurine/metabolism
18.
J Gen Physiol ; 72(5): 607-30, 1978 Nov.
Article in English | MEDLINE | ID: mdl-739255

ABSTRACT

In the dark, the photoaffinity reagent, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate (NAP-taurine), acts as a reversible inhibitor of red cell anion exchange when it is present either within the cell or in the external solution. A detailed analysis of the inhibition kinetics, however, reveals substantial differences in the responses to the probe at the two sides of the membrane. On the inside of the cell, NAP-taurine is a relatively low affinity inhibitor of chloride exchange (Ki = 370 microM). Both the effects of chloride on NAP-taurine inhibition and the affinity of NAP-taurine for the system as a substrate are consistent with the concept that internal NAP-taurine competes with chloride for the substrate site of the anion exchange system. External NAP-taurine, on the other hand, is a far more potent inhibitor of chloride exchange (Ki = 20 microM). It acts at a site of considerably lower affinity for chloride than the substrate site, probably the modifier site, at which halide anions are reported to cause a noncompetitive inhibition of chloride transport. NAP-taurine therefore seems to interact preferentially with either the substrate or modifier site of the transport system, depending on the side of the membrane at which it is present. It is suggested that the modifier site is accessible to NAP-taurine only from the outside whereas the transport site may be accessible from either side.


Subject(s)
Cell Membrane Permeability/drug effects , Erythrocyte Membrane/drug effects , Erythrocytes/drug effects , Taurine/analogs & derivatives , Binding Sites , Binding, Competitive , Chlorides/metabolism , Humans , Membrane Potentials , Nitrobenzenes/pharmacology , Nystatin/pharmacology , Stilbenes/pharmacology , Taurine/pharmacology , Water/metabolism
19.
J Gen Physiol ; 72(5): 631-49, 1978 Nov.
Article in English | MEDLINE | ID: mdl-739256

ABSTRACT

Exposure of cells to intense light with the photoactivatable reagent, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate (NAP-taurine), present in the external medium results in irreversible inhibition of chloride or sulfate exchange. This irreversible inhibition seems to result from covalent reaction with the same sites to which NAP-taurine binds reversibly in the dark. As shown in the preceding paper, high chloride concentrations decrease the reversible inhibition by NAP-taurine in the dark, in a manner suggesting that NAP-taurine and chloride compete for the modifier site of the anion transport system. In a similar fashion, high chloride concentrations in the medium during exposure to light cause a decrease in both the irreversible binding of NAP-taurine to the membrane and the inhibition of chloride exchange. Most of the chloride-sensitive irreversibly bound NAP-taurine is found in the 95,000 dalton polypeptide known as band 3 and, after pronase treatment of intact cells, in the 65,000 dalton fragment of this protein produced by proteolytic cleavage. After chymotrypsin treatment of ghosts, the NAP-taurine is localized in the 17,000 dalton transmembrane portion of this fragment. Although the possible involvement of minor labeled proteins cannot be rigorously excluded, the modifier site labeled by external NAP-taurine appears, therefore, to be located in the same portion of the 95,000 dalton polypeptide as is the transport site.


Subject(s)
Cell Membrane Permeability , Erythrocyte Membrane/metabolism , Erythrocytes/metabolism , Membrane Proteins/metabolism , Taurine/analogs & derivatives , Affinity Labels , Binding Sites/drug effects , Chlorides/metabolism , Chlorides/pharmacology , Erythrocyte Membrane/analysis , Erythrocyte Membrane/radiation effects , Humans , Light , Nitrobenzenes/pharmacology , Sulfates/metabolism , Taurine/pharmacology
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