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1.
Neuropathol Appl Neurobiol ; 46(5): 422-430, 2020 08.
Article in English | MEDLINE | ID: mdl-31867747

ABSTRACT

AIMS: DNA methylation-based central nervous system (CNS) tumour classification has identified numerous molecularly distinct tumour types, and clinically relevant subgroups among known CNS tumour entities that were previously thought to represent homogeneous diseases. Our study aimed at characterizing a novel, molecularly defined variant of glioneuronal CNS tumour. PATIENTS AND METHODS: DNA methylation profiling was performed using the Infinium MethylationEPIC or 450 k BeadChip arrays (Illumina) and analysed using the 'conumee' package in R computing environment. Additional gene panel sequencing was also performed. Tumour samples were collected at the German Cancer Research Centre (DKFZ) and provided by multinational collaborators. Histological sections were also collected and independently reviewed. RESULTS: Genome-wide DNA methylation data from >25 000 CNS tumours were screened for clusters separated from established DNA methylation classes, revealing a novel group comprising 31 tumours, mainly found in paediatric patients. This DNA methylation-defined variant of low-grade CNS tumours with glioneuronal differentiation displays recurrent monosomy 14, nuclear clusters within a morphology that is otherwise reminiscent of oligodendroglioma and other established entities with clear cell histology, and a lack of genetic alterations commonly observed in other (paediatric) glioneuronal entities. CONCLUSIONS: DNA methylation-based tumour classification is an objective method of assessing tumour origins, which may aid in diagnosis, especially for atypical cases. With increasing sample size, methylation analysis allows for the identification of rare, putative new tumour entities, which are currently not recognized by the WHO classification. Our study revealed the existence of a DNA methylation-defined class of low-grade glioneuronal tumours with recurrent monosomy 14, oligodendroglioma-like features and nuclear clusters.


Subject(s)
Central Nervous System Neoplasms/genetics , Central Nervous System Neoplasms/pathology , Chromosomes, Human, Pair 14/genetics , Glioma/genetics , Glioma/pathology , DNA Methylation , Female , Humans , Male , Monosomy , Neurocytoma/genetics , Neurocytoma/pathology , Oligodendroglioma/genetics , Oligodendroglioma/pathology
2.
BMC Pulm Med ; 19(1): 146, 2019 Aug 13.
Article in English | MEDLINE | ID: mdl-31409396

ABSTRACT

BACKGROUND: Clinical studies demonstrate that ivacaftor (IVA) improves health-related quality of life (HRQoL) in patients aged ≥6 years with cystic fibrosis (CF). The real-world impact of IVA and standard of care (SOC) in groups of patients with G551D and F508del mutations, respectively, was assessed using a survey comprising disease-specific and generic HRQoL measures. METHODS: Patients with CF aged ≥12 years, or aged 6-11 years with caregiver support, with either (1) a G551D mutation and receiving IVA (G551D/IVA) for ≥3 months, or (2) homozygous for F508del and receiving SOC before lumacaftor/IVA availability (F508del/SOC), were eligible to participate in a cross-sectional survey. Demographic and clinical characteristics, and HRQoL measures were compared between patient groups, and multiple regression analyses were conducted. RESULTS: After differences in patient demographic and clinical characteristics were controlled for, significantly better scores were observed in the G551D/IVA group than in the F508del/SOC group on multiple domains of the validated Cystic Fibrosis Questionnaire-Revised and the EuroQol 5-dimensions 5-level questionnaire. CONCLUSIONS: G551D/IVA patients reported better HRQoL than F508del/SOC patients on generic and disease-specific measures in a real-world setting.


Subject(s)
Aminophenols/therapeutic use , Aminopyridines/therapeutic use , Benzodioxoles/therapeutic use , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis/drug therapy , Cystic Fibrosis/genetics , Quinolones/therapeutic use , Child , Cross-Sectional Studies , Drug Combinations , Female , Forced Expiratory Volume , Humans , Internationality , Male , Multivariate Analysis , Mutation , Patient Reported Outcome Measures , Quality of Life , Regression Analysis , Surveys and Questionnaires
3.
Am J Physiol Renal Physiol ; 312(3): F489-F501, 2017 03 01.
Article in English | MEDLINE | ID: mdl-28003191

ABSTRACT

Calcineurin dephosphorylates nuclear factor of activated T cells transcription factors, thereby facilitating T cell-mediated immune responses. Calcineurin inhibitors are instrumental for immunosuppression after organ transplantation but may cause side effects, including hypertension and electrolyte disorders. Kidneys were recently shown to display activation of the furosemide-sensitive Na-K-2Cl cotransporter (NKCC2) of the thick ascending limb and the thiazide-sensitive Na-Cl cotransporter (NCC) of the distal convoluted tubule upon calcineurin inhibition using cyclosporin A (CsA). An involvement of major hormones like angiotensin II or arginine vasopressin (AVP) has been proposed. To resolve this issue, the effects of CsA treatment in normal Wistar rats, AVP-deficient Brattleboro rats, and cultured renal epithelial cells endogenously expressing either NKCC2 or NCC were studied. Acute administration of CsA to Wistar rats rapidly augmented phosphorylation levels of NKCC2, NCC, and their activating kinases suggesting intraepithelial activating effects. Chronic CsA administration caused salt retention and hypertension, along with stimulation of renin and suppression of renal cyclooxygenase 2, pointing to a contribution of endocrine and paracrine mechanisms at long term. In Brattleboro rats, CsA induced activation of NCC, but not NKCC2, and parallel effects were obtained in cultured cells in the absence of AVP. Stimulation of cultured thick ascending limb cells with AVP agonist restored their responsiveness to CsA. Our results suggest that the direct epithelial action of calcineurin inhibition is sufficient for the activation of NCC, whereas its effect on NKCC2 is more complex and requires concomitant stimulation by AVP.


Subject(s)
Calcineurin Inhibitors/toxicity , Cyclosporine/toxicity , Epithelial Cells/drug effects , Immunosuppressive Agents/toxicity , Kidney Tubules, Distal/drug effects , Loop of Henle/drug effects , Solute Carrier Family 12, Member 1/agonists , Animals , Arginine Vasopressin/pharmacology , Cells, Cultured , Cyclooxygenase 2/metabolism , Epithelial Cells/metabolism , Hypertension/chemically induced , Hypertension/metabolism , Hypertension/physiopathology , Kidney Tubules, Distal/metabolism , Kidney Tubules, Distal/physiopathology , Loop of Henle/metabolism , Loop of Henle/physiopathology , Male , Rats, Brattleboro , Rats, Wistar , Renin/metabolism , Solute Carrier Family 12, Member 1/genetics , Solute Carrier Family 12, Member 1/metabolism , Solute Carrier Family 12, Member 3/agonists , Solute Carrier Family 12, Member 3/genetics , Solute Carrier Family 12, Member 3/metabolism , Time Factors , Water-Electrolyte Balance/drug effects
4.
Vet Surg ; 46(3): 417-421, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28158935

ABSTRACT

OBJECTIVE: To compare a 2-layer closure with suture line reversal for a pelvic flexure enterotomy to 1-layer and traditional 2-layer hand sewn closures. STUDY DESIGN: Ex vivo, simple randomized study. SAMPLE POPULATION: Large colon segments from adult horses (n = 18). METHODS: Pelvic flexures were harvested from 18 horses and randomly assigned to 1 of 3 closure techniques (n = 6 per technique). A 10-cm enterotomy was made in each pelvic flexure and closed with the assigned technique. Closure time, luminal diameter via contrast radiographs, and bursting pressure were recorded for each specimen and compared between techniques using 1-way ANOVA with Duncan post hoc test at P < .05. RESULTS: There was a significant difference in closure time (P = .034) with 1-layer closure faster than both the traditional 2-layer closure (P=.024) and the 2-layer closure with suture line reversal (P = .030). There was no significant difference in luminal diameter or bursting pressure between the 3 closure techniques. CONCLUSIONS: Two-layer closure with suture line reversal may be an alternative to traditional 2-layer closure for closure of the pelvic flexure based on ex vivo bursting pressure testing and closure time. A 1-layer simple continuous closure resisted bursting pressure not different to both 2-layer closure techniques. Further in vivo evaluation may be indicated.


Subject(s)
Anastomosis, Surgical/veterinary , Colon/surgery , Enterostomy/veterinary , Suture Techniques/veterinary , Sutures/veterinary , Animals , Biomechanical Phenomena , Horses , Pressure , Suture Techniques/instrumentation
5.
Neuropathol Appl Neurobiol ; 40(3): 327-36, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24127995

ABSTRACT

AIMS: A few case series in adults have described the characteristics of epithelioid glioblastoma (e-GB), one of the rarest variants of this cancer. We evaluated clinical, radiological, histological and molecular characteristics in the largest series to date of paediatric e-GB. METHODS: Review of clinical characteristics and therapy, imaging studies and histology was performed in patients younger than 22 years with e-GB seen at our institution over 15 years. Sequencing of hotspot mutations and fluorescence in situ hybridization of relevant genes were undertaken. RESULTS: Median age at diagnosis of six patients was 7.6 years. Tumours originated in the cerebral cortex (n = 2) or diencephalon (n = 4). Three patients presented with acute, massive haemorrhage and three had leptomeningeal dissemination at diagnosis. Paediatric e-GB had the typical histological characteristics seen in adult tumours. Universal immunoreactivity for INI1 and lack of diverse protein expression were seen in all cases. One tumour had a chromosome 22q loss. Three tumours (50%) harboured a BRAF: p.V600E. One thalamic tumour had an H3F3A p.K27M. All patients received radiation therapy with (n = 3) or without chemotherapy (n = 3). All patients experienced tumour progression with a median survival of 169 days. One patient with nonmetastatic disease had early leptomeningeal progression. Two patients had symptomatic tumour spread outside the central nervous system (CNS) through a ventriculoperitoneal shunt. One additional patient had widespread metastases outside the CNS identified at autopsy. CONCLUSIONS: Paediatric e-GBs are rare cancers with an aggressive behaviour that share histological and genetic characteristics with their adult counterparts. BRAF inhibition is a potential treatment for these tumours.


Subject(s)
Brain Neoplasms/diagnosis , Glioblastoma/diagnosis , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Child , Child, Preschool , Female , Glioblastoma/diagnostic imaging , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Male , Radiography
6.
Life (Basel) ; 14(1)2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38255720

ABSTRACT

Polar bears (Ursus maritimus) face a number of challenges that threaten the survival of the species. Captive breeding represents one essential facet of species conservation, but aspects of the polar bear's reproductive physiology, such as follicle maturation, coitus-induced ovulation, and pseudopregnancy, are poorly characterized and present challenges for enhancing natural reproductive success and the application of advanced reproductive techniques. Due to the absence of a reliable transrectal or transabdominal ultrasound method for ovarian examination in the species, the ovaries of two adult female polar bears were examined laparoscopically to evaluate the feasibility of surgical access to the ovaries, oviduct, and uterus. The minimally invasive procedure was easily and rapidly performed in both bears and all procedures. Direct visual assessment of the ovary was possible after dissection of a fatty bursal sac, which completely enclosed the ovaries. In the second bear, laparoscopic manipulation of the ovary to draw it closer to the body wall enabled transcutaneous ultrasound. Laparoscopy may be a valuable tool to aid in the application of advanced reproductive technologies in polar bears.

7.
Nat Genet ; 12(1): 24-30, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8528245

ABSTRACT

Maintenance of fluid and electrolyte homeostasis is critical for normal neuromuscular function. Bartter's syndrome is an autosomal recessive disease characterized by diverse abnormalities in electrolyte homeostasis including hypokalaemic metabolic alkalosis; Gitelman's syndrome represents the predominant subset of Bartter's patients having hypomagnesemia and hypocalciuria. We now demonstrate complete linkage of Gitelman's syndrome to the locus encoding the renal thiazide-sensitive Na-Cl cotransporter, and identify a wide variety of non-conservative mutations, consistent with loss of function alleles, in affected subjects. These findings demonstrate the molecular basis of Gitelman's syndrome. We speculate that these mutant alleles lead to reduced sodium chloride reabsorption in the more common heterozygotes, potentially protecting against development of hypertension.


Subject(s)
Bartter Syndrome/genetics , Carrier Proteins/genetics , Chlorides/metabolism , Receptors, Drug/genetics , Sodium/metabolism , Symporters , Amino Acid Sequence , Animals , Base Sequence , Biological Transport , Chromosomes, Human, Pair 16 , Cloning, Molecular , DNA Primers/chemistry , Dinucleotide Repeats , Female , Flounder , Genetic Linkage , Humans , Male , Molecular Sequence Data , Pedigree , Point Mutation , Polymorphism, Single-Stranded Conformational , Rats , Sequence Alignment , Sodium Chloride Symporters , Solute Carrier Family 12, Member 3
8.
Article in English | MEDLINE | ID: mdl-36638539

ABSTRACT

Objective: To identify and summarize data that describe the impact of effectively treating major depressive disorder (MDD) on the severity or risk of serious comorbidities.Data Sources: MEDLINE, Embase, PsycINFO, Cochrane Database of Systematic Reviews, and several congresses were searched. Searches included terms related to MDD, randomized controlled trials (RCTs), and physical comorbidities and were restricted to English-language publications. Searches were conducted in November 2019 for the previous 2 years for conference proceedings; no date restriction was applied to the database searches.Study Selection: Included studies were RCTs or meta-analyses that assessed depression therapies. Studies were required to report a statistically significant improvement in depression scores as well as the concurrent impact on comorbidities. A total of 1,997 articles were initially identified for screening.Data Extraction: Two investigators extracted data and assessed study quality.Results: A total of 30 studies, including 24 RCTs (N = 6,333) and 6 meta/pooled analyses of RCTs, were included. Findings in several comorbidity categories were mixed; for example, in half (4 of 8) of the identified studies in people with cardiovascular disease and depression, individuals who received treatment leading to reduced depressive symptoms compared with a control arm also had a significantly decreased incidence of cardiovascular events or significantly improved cardiac disease symptom/severity scores compared with controls. Significant improvements in comorbid disease severity observed alongside improvements in depressive symptoms were also noted in studies of comorbid Parkinson's disease, multiple sclerosis, chronic pain and fibromyalgia, and chronic obstructive pulmonary disease.Conclusions: Effective treatment of MDD may lead to a reduction in the severity of certain serious comorbidities. These results highlight the importance of appropriate and timely treatment of MDD.


Subject(s)
Chronic Pain , Depressive Disorder, Major , Humans , Comorbidity , Depression/complications , Depression/epidemiology , Depression/therapy , Depressive Disorder, Major/complications , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/therapy , Systematic Reviews as Topic
9.
J Clin Psychiatry ; 83(6)2022 10 19.
Article in English | MEDLINE | ID: mdl-36264099

ABSTRACT

Objective: To summarize the breadth of data exploring the relationship between major depressive disorder (MDD) and both the incidence and the disease course of a range of comorbidities.Data Sources: The authors searched MEDLINE, Embase, PsycINFO, Cochrane Database of Systematic Reviews, and several prespecified congresses. Searches included terms related to MDD and several comorbidity categories, restricted to those published in the English language from 2005 onward.Study Selection: Eligibility criteria included observational studies within North America and Europe that examined the covariate-adjusted impact of MDD on the risk and/or severity of comorbidities. A total of 6,811 articles were initially identified for screening.Data Extraction: Two investigators extracted data and assessed study quality.Results: In total, 199 articles were included. Depression was significantly (P < .05) associated with an increased incidence of dementia and Alzheimer's disease as well as cognitive decline in individuals with existing disease; increased incidence and worsening of cardiovascular disease/events (although mixed results were found for stroke); worsening of metabolic syndrome; increased incidence of diabetes, particularly among men, and worsening of existing diabetes; increased incidence of obesity, particularly among women; increased incidence and worsening of certain autoimmune diseases; increased incidence and severity of HIV/AIDS; and increased incidence of drug abuse and severity of both alcohol and drug abuse.Conclusions: The presence of MDD was identified as a risk factor for both the development and the worsening of a range of comorbidities. These results highlight the importance of addressing depression early in its course and the need for integrating mental and general health care.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Depressive Disorder, Major , Female , Humans , Male , Alzheimer Disease/complications , Cognitive Dysfunction/complications , Comorbidity , Depressive Disorder, Major/diagnosis , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/complications
10.
AJNR Am J Neuroradiol ; 42(12): 2245-2250, 2021 12.
Article in English | MEDLINE | ID: mdl-34674998

ABSTRACT

BACKGROUND AND PURPOSE: Posterior fossa type A (PFA) ependymomas have 2 molecular subgroups (PFA-1 and PFA-2) and 9 subtypes. Gene expression profiling suggests that PFA-1 and PFA-2 tumors have distinct developmental origins at different rostrocaudal levels of the brainstem. We, therefore, tested the hypothesis that PFA-1 and PFA-2 ependymomas have different anatomic MR imaging characteristics at presentation. MATERIALS AND METHODS: Two neuroradiologists reviewed the preoperative MR imaging examinations of 122 patients with PFA ependymomas and identified several anatomic characteristics, including extension through the fourth ventricular foramina and encasement of major arteries and tumor type (midfloor, roof, or lateral). Deoxyribonucleic acid methylation profiling assigned ependymomas to PFA-1 or PFA-2. Information on PFA subtype from an earlier study was also available for a subset of tumors. Associations between imaging variables and subgroup or subtype were evaluated. RESULTS: No anatomic imaging variable was significantly associated with the PFA subgroup, but 5 PFA-2c subtype ependymomas in the cohort had a more circumscribed appearance and showed less tendency to extend through the fourth ventricular foramina or encase blood vessels, compared with other PFA subtypes. CONCLUSIONS: PFA-1 and PFA-2 ependymomas did not have different anatomic MR imaging characteristics, and these results do not support the hypothesis that they have distinct anatomic origins. PFA-2c ependymomas appear to have a more anatomically circumscribed MR imaging appearance than the other PFA subtypes; however, this needs to be confirmed in a larger study.


Subject(s)
Ependymoma , Infratentorial Neoplasms , Cohort Studies , Ependymoma/diagnostic imaging , Ependymoma/genetics , Ependymoma/pathology , Humans , Infratentorial Neoplasms/diagnostic imaging , Magnetic Resonance Imaging , Neuroimaging
11.
Stem Cells Transl Med ; 10(11): 1500-1515, 2021 11.
Article in English | MEDLINE | ID: mdl-34387402

ABSTRACT

The paracrine signaling, immunogenic properties and possible applications of mesenchymal stromal cells (MSCs) for cartilage tissue engineering and regenerative medicine therapies have been investigated through numerous in vitro, animal model and clinical studies. The emerging knowledge largely supports the concept of MSCs as signaling and modulatory cells, exerting their influence through trophic and immune mediation rather than as a cell replacement therapy. The virtues of allogeneic cells as a ready-to-use product with well-defined characteristics of cell surface marker expression, proliferative ability, and differentiation capacity are well established. With clinical applications in mind, a greater focus on allogeneic cell sources is evident, and this review summarizes the latest published and upcoming clinical trials focused on cartilage regeneration adopting allogeneic and autologous cell sources. Moreover, we review the current understanding of immune modulatory mechanisms and the role of trophic factors in articular chondrocyte-MSC interactions that offer feasible targets for evaluating MSC activity in vivo within the intra-articular environment. Furthermore, bringing labeling and tracking techniques to the clinical setting, while inherently challenging, will be extremely informative as clinicians and researchers seek to bolster the case for the safety and efficacy of allogeneic MSCs. We therefore review multiple promising approaches for cell tracking and labeling, including both chimerism studies and imaging-based techniques, that have been widely explored in vitro and in animal models. Understanding the distribution and persistence of transplanted MSCs is necessary to fully realize their potential in cartilage regeneration techniques and tissue engineering applications.


Subject(s)
Cartilage, Articular , Hematopoietic Stem Cell Transplantation , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Animals , Cell Differentiation , Chondrogenesis , Mesenchymal Stem Cell Transplantation/methods , Tissue Engineering/methods
13.
J Cyst Fibros ; 18(5): 737-742, 2019 09.
Article in English | MEDLINE | ID: mdl-30587335

ABSTRACT

BACKGROUND: We explored the time-dependent impact of pulmonary exacerbations (PEx) on health-related quality of life (HRQoL) using Cystic Fibrosis Questionnaire-Revised (CFQ-R) data from 2 large cystic fibrosis (CF) trials. METHODS: This exploratory post-hoc analysis evaluated the impact of PEx on CFQ-R domains of functioning in 80 patients with CF (homozygous for F508del-CFTR), aged ≥14 years randomized to placebo in the TRAFFIC and TRANSPORT trials who experienced 1 PEx. RESULTS: Scores on the CFQ-R were significantly lower within 1 week of PEx start in 8 out of 12 domains (Respiratory Symptoms, Physical Functioning, Emotional Functioning, Health Perceptions, Role Functioning, Social Functioning, Eating, and Vitality). Patients whose PEx was treated with hospitalization or intravenous antibiotics had greater reductions in some domains of HRQoL compared with those treated with oral antibiotics. In the immediate weeks post-PEx, improvement was seen on Emotional Functioning, Respiratory Symptoms, and Health Perceptions, while further decline was seen for Eating, Physical Functioning, Role Functioning, Vitality, and Weight. For some measures (Physical Functioning, Vitality), full recovery to pre-PEx levels took several weeks. CONCLUSIONS: Pulmonary exacerbations have significant effects on multiple domains of HRQoL, and recovery across multiple domains post-PEx can take several weeks. These findings provide insight into the impact of PEx on patient HRQoL and recovery post-PEx. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifiers, NCT01807923 and NCT01807949.


Subject(s)
Aminophenols/therapeutic use , Aminopyridines/therapeutic use , Benzodioxoles/therapeutic use , Cystic Fibrosis/drug therapy , Cystic Fibrosis/psychology , Quality of Life , Quinolones/therapeutic use , Recovery of Function , Adolescent , Cystic Fibrosis/complications , Disease Progression , Drug Combinations , Female , Humans , Male , Time Factors , Treatment Outcome
14.
J Am Vet Med Assoc ; 254(4): 508-511, 2019 Feb 15.
Article in English | MEDLINE | ID: mdl-30714863

ABSTRACT

CASE DESCRIPTION A 12-year-old mixed-breed mare (horse 1) and 6-year-old Friesian gelding (horse 2) were examined for chronic lameness associated with the stifle joint. CLINICAL FINDINGS Lameness examination revealed effusion of the right (horse 1) or left (horse 2) femoropatellar and medial femorotibial joints and grade 3/5 (horse 1) or 4/5 (horse 2) lameness. A diagnosis of cranial cruciate ligament (CCL) injury with associated mineralization and avulsion (horse 1) or mineralization alone (horse 2) was facilitated in both horses with a caudomedial-craniolateral oblique radiographic view obtained 45° medial to the caudocranial line, which highlighted the origin of the ligament on the caudoaxial aspect of the lateral femoral condyle within the intercondylar fossa. These lesions were subsequently confirmed via CT. TREATMENT AND OUTCOME Arthroscopy of the medial and lateral femorotibial joints was performed for horse 1 and revealed the osseous fragment associated with the CCL, but the fragment could not be removed. Horse 2 was euthanized while anesthetized following CT owing to the poor prognosis. CONCLUSIONS AND CLINICAL RELEVANCE Radiography is typically the first imaging modality attempted for horses with CCL injury, particularly outside the hospital setting. A 45° caudomedial-craniolateral oblique radiographic view may aid in diagnosis of CCL injury when avulsion or mineralization is present. Although this view is not commonly included in the typical radiographic series for imaging of the stifle joint in horses, it should be considered when CCL injury is suspected.


Subject(s)
Anterior Cruciate Ligament Injuries/veterinary , Anterior Cruciate Ligament/diagnostic imaging , Horse Diseases/diagnostic imaging , Radiography/veterinary , Animals , Anterior Cruciate Ligament/pathology , Anterior Cruciate Ligament Injuries/diagnostic imaging , Anterior Cruciate Ligament Injuries/pathology , Calcification, Physiologic , Female , Horse Diseases/pathology , Horses , Lameness, Animal/diagnostic imaging , Lameness, Animal/etiology , Male , Stifle/diagnostic imaging , Stifle/pathology
15.
J Clin Invest ; 83(1): 113-26, 1989 Jan.
Article in English | MEDLINE | ID: mdl-2910903

ABSTRACT

We studied the effects of dietary NaCl intake on the renal distal tubule by feeding rats high or low NaCl chow or by chronically infusing furosemide. Furosemide-treated animals were offered saline as drinking fluid to replace urinary losses. Effects of naCl intake were evaluated using free-flow micropuncture, in vivo microperfusion, and morphometric techniques. Dietary NaCl restriction did not affect NaCl delivery to the early distal tubule but markedly increased the capacity of the distal convoluted tubule to transport Na and Cl. Chronic furosemide infusion increased NaCl delivery to the early distal tubule and also increased the rates of Na and Cl transport above the rates observed in low NaCl diet rats. When compared with high NaCl intake alone, chronic furosemide infusion with saline ingestion increased the fractional volume of distal convoluted tubule cells by nearly 100%, whereas dietary NaCl restriction had no effect. The results are consistent with the hypotheses that (a) chronic NaCl restriction increases the transport ability of the distal convoluted tubule independent of changes in tubule structure, (b) high rates of ion delivery to the distal nephron cause tubule hypertrophy, and (c) tubule hypertrophy is associated with increases in ion transport capacity. They indicate that the distal tubule adapts functionally and structurally to perturbations in dietary Na and Cl intake.


Subject(s)
Diuretics/pharmacology , Kidney Tubules, Distal/physiology , Kidney Tubules/physiology , Sodium, Dietary/pharmacology , Adaptation, Physiological/drug effects , Animals , Chlorides/pharmacokinetics , Diuretics/administration & dosage , Furosemide/pharmacology , Male , Microscopy, Electron , Rats , Rats, Inbred Strains , Sodium/pharmacokinetics , Sodium Chloride/administration & dosage , Sodium Chloride/pharmacology , Sodium, Dietary/administration & dosage
16.
J Clin Invest ; 98(3): 635-40, 1996 Aug 01.
Article in English | MEDLINE | ID: mdl-8698854

ABSTRACT

Sodium and chloride transport by the macula densa and thick ascending limb of Henle's loop participates importantly in extracellular fluid volume homeostasis, urinary concentration and dilution, control of glomerular filtration, and control of renal hemodynamics. Transepithelial Na and Cl transport across the apical membrane of thick ascending limb (TALH) cells is mediated predominantly by a loop diuretic sensitive Na-K-2Cl cotransport pathway. The corresponding transport protein has recently been cloned. Functional studies suggest that the cotransporter is expressed by macula densa cells as well as by TALH cells. The current studies were designed to identify sites of Na-K-2Cl cotransporter expression along distal nephron in rabbit and rat. Non-isotopic high-resolution in situ hybridization, using an antisense probe for the apical form of the Na-K-2Cl cotransporter identified expression throughout the TALH, from the junction between inner and outer medulla to the transition to distal convoluted tubule. Expression by macula densa cells was confirmed by colocalization using markers specific for macula densa cells. First, Na-K-2Cl cotransporter mRNA was detected in macula densa cells that did not stain with anti-Tamm-Horsfall protein antibodies. Second, Na-K-2Cl cotransporter mRNA was detected in macula densa cells that show positive NADPH-diaphorase reaction, indicating high levels of constitutive nitric oxide synthase activity. In rat, levels of Na-K-2Cl cotransporter mRNA expression were similar in TALH and macula densa cells. In rabbit, expression levels were higher in macula densa cells than in surrounding TALH cells. The present data provide morphological support for a previously established functional concept that Na-K-2Cl cotransport at the TALH is accomplished by the expression of a well-defined cotransporter. At the macula densa, this transporter may establish a crucial link between tubular salt load and glomerular vascular regulation.


Subject(s)
Carrier Proteins/genetics , Chlorides/metabolism , Kidney Tubules, Distal/chemistry , Loop of Henle/chemistry , Potassium/metabolism , RNA, Messenger/analysis , Sodium/metabolism , Animals , Male , Rabbits , Rats , Rats, Sprague-Dawley , Sodium-Potassium-Chloride Symporters
17.
J Clin Invest ; 96(5): 2510-4, 1995 Nov.
Article in English | MEDLINE | ID: mdl-7593642

ABSTRACT

A thiazide-sensitive Na-Cl cotransporter contributes importantly to mammalian salt homeostasis by mediating Na-Cl transport along the renal distal tubule. Although it has been accepted that thiazide-sensitive Na-Cl cotransport occurs predominantly along the distal convoluted tubule in rats and mice, sites of expression in the rabbit have been controversial. A commonly accepted model of rabbit distal nephron transport pathways identifies the connecting tubule, not the distal convoluted tubule, as the predominant site of thiazide-sensitive Na-Cl cotransport. The thiazide-sensitive Na-Cl cotransporter has been cloned recently. The present experiments were designed to localize sites of thiazide-sensitive Na-Cl cotransporter mRNA expression along the rabbit distal nephron. Nonradioactive in situ hybridization with a thiazide-sensitive Na-Cl cotransporter probe was combined with immunocytochemistry with an antibody that recognizes distal convoluted tubule cells and with a Na+/Ca2+ exchanger antibody that recognizes only connecting tubule cells. The results indicate that thiazide-sensitive Na-Cl cotransporter mRNA is highly expressed by cells of the distal convoluted tubule and not by connecting tubule cells. Segments that stain with the Na+/Ca2+ exchanger antibody (connecting tubules) do not demonstrate thiazide-sensitive Na-Cl cotransporter mRNA expression. We conclude that the predominant site of thiazide-sensitive Na-Cl cotransporter mRNA expression in rabbit distal nephron is the distal convoluted tubule and that sites of mRNA expression of electroneutral Na and Cl transport are similar in rabbits, rats, and mice.


Subject(s)
Benzothiadiazines , Carrier Proteins/metabolism , Chlorides/metabolism , Kidney Tubules/metabolism , RNA, Messenger/analysis , Sodium Chloride Symporter Inhibitors/pharmacology , Sodium/metabolism , Symporters , Animals , Diuretics , Male , Rabbits , Sodium Chloride Symporters
18.
Clin Nephrol ; 67(5): 306-17, 2007 May.
Article in English | MEDLINE | ID: mdl-17542340

ABSTRACT

AIM: This study was designed to assess the potential of the continuous erythropoietin receptor activator (C.E.R.A.) to correct anemia at extended administration intervals in erythropoiesis-stimulating agent-naive patients with chronic kidney disease (CKD) not on dialysis and to determine its optimal starting dose. METHODS: Patients were assigned to subcutaneous C.E.R.A. at 3 doses: 0.15, 0.30 and 0.60 microg/kg/wk. During the first 6 weeks, dose adjustments for efficacy were not permitted in order to assess dose response. Within each of the 3 dose groups, patients were randomized to receive C.E.R.A. QW, Q2W or Q3W; the total dose during the first 6 weeks was the same for a particular dose group across the frequency subgroups. During the next 12 weeks, dose was adjusted according to predefined hemoglobin (Hb) criteria. The primary efficacy parameter was change in Hb over 6 weeks, estimated from regression analysis between baseline and the point at which the patient received a dose change or blood transfusion. It therefore provided an estimate of Hb increase based on starting dose. Other endpoints included Hb response rate (proportion of patients with a Hb increase > 1.0 g/dl on 2 consecutive occasions). A 1-year extension period investigated long term tolerability and efficacy. RESULTS: A dose-dependent relationship was noted in the mean change in Hb from baseline over 6 weeks (p < 0.0001), independent of administration schedule (p = 0.9201). There was also a significant relationship between Hb change and median serum C.E.R.A. concentration (p < 0.0001). Erythropoietic responses were sustained in all groups with mean changes from baseline in Hb > 1.2 g/dl observed at doses > or = 0.30 microg/kg/wk. Hb response rate increased with increasing dose: 67, 72 and 90% with C.E.R.A. 0.15, 0.30 and 0.60 microg/kg/wk, respectively. Generally, the median Hb response time was faster with increasing dose (89, 43 and 31 days, respectively). Response was unrelated to administration frequency. Stable Hb concentrations were maintained throughout the 1-year extension period. C.E.R.A. was generally well tolerated, and the most common adverse events were hypertension, urinary tract infection and renal failure. CONCLUSIONS: C.E.R.A. corrected anemia and maintained sustained and stable control of Hb over 1 year. These results suggest that 0.60 microg/kg subcutaneous C.E.R.A. given twice monthly is a suitable starting dose for further investigation in Phase III studies in patients with CKD not on dialysis.


Subject(s)
Anemia/drug therapy , Anemia/etiology , Erythropoietin/administration & dosage , Kidney Failure, Chronic/complications , Polyethylene Glycols/administration & dosage , Renal Dialysis , Adult , Aged , Aged, 80 and over , Analysis of Variance , Area Under Curve , Biomarkers/blood , Dose-Response Relationship, Drug , Erythropoiesis/drug effects , Erythropoietin/adverse effects , Erythropoietin/blood , Female , Ferritins/blood , Ferritins/drug effects , Follow-Up Studies , Hemoglobins/drug effects , Humans , Male , Middle Aged , Polyethylene Glycols/adverse effects , Recombinant Proteins , Regression Analysis , Time Factors , Treatment Outcome
20.
Cancer Res ; 51(12): 3267-73, 1991 Jun 15.
Article in English | MEDLINE | ID: mdl-1645617

ABSTRACT

The modal chromosome number of 13 non-small cell lung carcinomas placed into culture was compared to the DNA index of the tumor tissue as measured by flow cytometry in order to determine whether cytogenetic results from such cultures are representative of the original solid tumor. The modal chromosome number observed in culture, which ranged from 45-146, fell within the range of aneuploidy predicted from the DNA content of the original tissue in all 13 cases. In 7 cases, flow cytometry results showed that the aneuploid G1/G0 population of the tumor tissue (DNA index of 1.5 or higher) represented 11-76% of the cells present, while diploid cells (presumably normal tissue) made up the remainder of the population. In these 7 cases, modal chromosome numbers of 61-92 were found in tumor cells cultured from the tissue. In 3 cases, only a diploid or near-diploid population was found by flow cytometry, consistent with the near-diploid modal chromosome number of cultured cells observed (45-55). In 3 cases, the aneuploid G1/G0 population (DNA index of 1.5, 1.6, and 3.2) of the original tissue represented only a small fraction of the solid tumor (1-5% of cells). Modal chromosome number found in cells cultured from these 3 cases was 64-69, 62-68, and 136-146, which is in close agreement with the aneuploid peak observed in the tissue. Histological analysis of the tumor tissue in two of the latter cases showed large numbers of infiltrating lymphocytes and/or stromal tissue which could have dominated the measurement by flow cytometry. In the third case, tumor cells made up at least 75% of the specimen examined, implying that part of the population in the "diploid" peak contained tumor cells in this specimen. Only the aneuploid population was detected in culture of this tumor. Agreement between flow cytometry and cytogenetics was found in cases in which metaphase spreads were obtained within a few days of culture as well as after several months. These results indicate that highly aneuploid populations are found in many, but not all, non-small cell lung tumors. Although in some cases multiple populations may exist in the tumor which do not all proliferate in vitro, tumor cells which are found in culture of solid lung carcinomas are representative of the original tumor. Flow cytometry findings in the solid tumors confirmed the findings of aneuploidy observed by cytogenetic analysis.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Karyotyping , Lung Neoplasms/genetics , Aneuploidy , Animals , Carcinoma, Non-Small-Cell Lung/pathology , Cell Cycle , Cell Line , Chromosome Banding , DNA, Neoplasm/analysis , Flow Cytometry , Lung Neoplasms/pathology , Mice , Tumor Cells, Cultured/cytology
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