Cystitis: Inflammation of the URINARY BLADDER, either from bacterial or non-bacterial causes. Cystitis is usually associated with painful urination (dysuria), increased frequency, urgency, and suprapubic pain.Lung Diseases, Interstitial: A diverse group of lung diseases that affect the lung parenchyma. They are characterized by an initial inflammation of PULMONARY ALVEOLI that extends to the interstitium and beyond leading to diffuse PULMONARY FIBROSIS. Interstitial lung diseases are classified by their etiology (known or unknown causes), and radiological-pathological features.Urinary Bladder: A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.Cystitis, Interstitial: A condition with recurring discomfort or pain in the URINARY BLADDER and the surrounding pelvic region without an identifiable disease. Severity of pain in interstitial cystitis varies greatly and often is accompanied by increased urination frequency and urgency.Urinary Bladder Diseases: Pathological processes of the URINARY BLADDER.Interstitial Cells of Cajal: c-Kit positive cells related to SMOOTH MUSCLE CELLS that are intercalated between the autonomic nerves and the effector smooth muscle cells of the GASTROINTESTINAL TRACT. Different phenotypic classes play roles as pacemakers, mediators of neural inputs, and mechanosensors.Cystoscopy: Endoscopic examination, therapy or surgery of the urinary bladder.Pelvic Pain: Pain in the pelvic region of genital and non-genital origin and of organic or psychogenic etiology. Frequent causes of pain are distension or contraction of hollow viscera, rapid stretching of the capsule of a solid organ, chemical irritation, tissue ischemia, and neuritis secondary to inflammatory, neoplastic, or fibrotic processes in adjacent organs. (Kase, Weingold & Gershenson: Principles and Practice of Clinical Gynecology, 2d ed, pp479-508)Urothelium: The epithelial lining of the URINARY TRACT.Pentosan Sulfuric Polyester: A sulfated pentosyl polysaccharide with heparin-like properties.Extracellular Fluid: The fluid of the body that is outside of CELLS. It is the external environment for the cells.BK Virus: A species of POLYOMAVIRUS apparently infecting over 90% of children but not clearly associated with any clinical illness in childhood. The virus remains latent in the body throughout life and can be reactivated under certain circumstances.Pyelonephritis: Inflammation of the KIDNEY involving the renal parenchyma (the NEPHRONS); KIDNEY PELVIS; and KIDNEY CALICES. It is characterized by ABDOMINAL PAIN; FEVER; NAUSEA; VOMITING; and occasionally DIARRHEA.Hematuria: Presence of blood in the urine.Administration, Intravesical: The instillation or other administration of drugs into the bladder, usually to treat local disease, including neoplasms.Polyomavirus Infections: Infections with POLYOMAVIRUS, which are often cultured from the urine of kidney transplant patients. Excretion of BK VIRUS is associated with ureteral strictures and CYSTITIS, and that of JC VIRUS with progressive multifocal leukoencephalopathy (LEUKOENCEPHALOPATHY, PROGRESSIVE MULTIFOCAL).Urine: Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the URETHRA.Hemorrhage: Bleeding or escape of blood from a vessel.Urinary Tract Infections: Inflammatory responses of the epithelium of the URINARY TRACT to microbial invasions. They are often bacterial infections with associated BACTERIURIA and PYURIA.Vulvodynia: Complex pain syndrome with unknown etiology, characterized by constant or intermittent generalized vulva pain (Generalized vulvodynia) or localized burning sensations in the VESTIBULE area when pressure is applied (Vestibulodynia, or Vulvar Vestibulitis Syndrome). Typically, vulvar tissue with vulvodynia appears normal without infection or skin disease. Vulvodynia impacts negatively on a woman's quality of life as it interferes with sexual and daily activities.Idiopathic Interstitial Pneumonias: A group of interstitial lung diseases with no known etiology. There are several entities with varying patterns of inflammation and fibrosis. They are classified by their distinct clinical-radiological-pathological features and prognosis. They include IDIOPATHIC PULMONARY FIBROSIS; CRYPTOGENIC ORGANIZING PNEUMONIA; and others.Pulmonary Fibrosis: A process in which normal lung tissues are progressively replaced by FIBROBLASTS and COLLAGEN causing an irreversible loss of the ability to transfer oxygen into the bloodstream via PULMONARY ALVEOLI. Patients show progressive DYSPNEA finally resulting in death.Anti-Infective Agents, Urinary: Substances capable of killing agents causing urinary tract infections or of preventing them from spreading.Urinary Bladder, Overactive: Symptom of overactive detrusor muscle of the URINARY BLADDER that contracts with abnormally high frequency and urgency. Overactive bladder is characterized by the frequent feeling of needing to urinate during the day, during the night, or both. URINARY INCONTINENCE may or may not be present.Mesna: A sulfhydryl compound used to prevent urothelial toxicity by inactivating metabolites from ANTINEOPLASTIC AGENTS, such as IFOSFAMIDE or CYCLOPHOSPHAMIDE.Cyclophosphamide: Precursor of an alkylating nitrogen mustard antineoplastic and immunosuppressive agent that must be activated in the LIVER to form the active aldophosphamide. It has been used in the treatment of LYMPHOMA and LEUKEMIA. Its side effect, ALOPECIA, has been used for defleecing sheep. Cyclophosphamide may also cause sterility, birth defects, mutations, and cancer.Extracellular Space: Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.AcroleinPyelitis: Inflammation of the KIDNEY PELVIS and KIDNEY CALICES where urine is collected before discharge, but does not involve the renal parenchyma (the NEPHRONS) where urine is processed.Fibrosis: Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.Uroplakin III: A uroplakin subtype that heterodimerizes with UROPLAKIN IB to form a component of the asymmetric unit membrane found in urothelial cells.Uropathogenic Escherichia coli: Strains of Escherichia coli that preferentially grow and persist within the urinary tract. They exhibit certain virulence factors and strategies that cause urinary tract infections.Nitrofurantoin: A urinary anti-infective agent effective against most gram-positive and gram-negative organisms. Although sulfonamides and antibiotics are usually the agents of choice for urinary tract infections, nitrofurantoin is widely used for prophylaxis and long-term suppression.Uroplakin II: A uroplakin subtype that heterodimerizes with UROPLAKIN IA to form a component of the asymmetric unit membrane found in urothelial cells.Urination: Discharge of URINE, liquid waste processed by the KIDNEY, from the body.Prostatitis: Infiltration of inflammatory cells into the parenchyma of PROSTATE. The subtypes are classified by their varied laboratory analysis, clinical presentation and response to treatment.Escherichia coli Infections: Infections with bacteria of the species ESCHERICHIA COLI.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.Ulcer: A lesion on the surface of the skin or a mucous surface, produced by the sloughing of inflammatory necrotic tissue.Bacteriuria: The presence of bacteria in the urine which is normally bacteria-free. These bacteria are from the URINARY TRACT and are not contaminants of the surrounding tissues. Bacteriuria can be symptomatic or asymptomatic. Significant bacteriuria is an indicator of urinary tract infection.