Activation of CNS circuits producing a neurogenic cystitis: evidence for centrally induced peripheral inflammation

We present a model of neurogenic cystitis induced by viral infection of specific neuronal circuits of the rat CNS. Retrograde infection by pseudorabies virus (PRV) of neuronal populations neighboring those that innervate the bladder consistently led to a localized immune response in the CNS and bladder inflammation. Infection of bladder circuits themselves or of circuits distant from these rarely produced cystitis. Absence of virus in bladder and urine ruled out an infectious cystitis. Total denervation of the bladder, selective C-fiber deafferentation, or bladder sympathectomy prevented cystitis without affecting the CNS disease, indicating a neurogenic component to the inflammation. The integrity of central bladder-related circuits is necessary for the appearance of bladder inflammation, because only CNS lesions affecting bladder circuits, i.e., bilateral dorsolateral or ventrolateral funiculectomy, as well as bilateral lesions of Barrington's nucleus/locus coeruleus area, prevented bladder inflammation. The close proximity in the CNS of noninfected visceral circuits to infected somatic neurons would thus permit a bystander effect, leading to activation of the sensory and autonomic circuits innervating the bladder and resulting in a neurogenic inflammation localized to the bladder. The present study indicates that CNS dysfunction can bring about a peripheral inflammation.     

Effects of tamoxifen on the cytology of the uterine cervix in breast cancer patients

Knowledge about the central innervation of the lower urinary tract is limited. The spinal cord and the pontine micturition center have been investigated most thoroughly, whereas high centers have received little attention. Pseudorabies virus (PRV), a self-amplifying and transneuronal tracer was injected into the bladder trigone of 21 Sprague-Dawley rats. The animals were killed after 72, 96, and 120 h. The whole CNS was sectioned and immunostained for PRV. CNS centers directly connected to the bladder include the intermedio lateral cell column, the central autonomic nucleus, and the nucleus intercalatus at the spinal cord levels T12-L2 and L6-S2. The raphe pallidus et magnus, the A5 nor-adrenergic area, the pontine micturition center, the locus coeruleus, the periaquaductal gray, the nucleus para- et periventricularis of the hypothalamus, the red nucleus, the medial preoptic area, and the cortex are supraspinal centers connected to the bladder. Lower urinary tract function is a complex multilevel and multineuronal interaction. It involves facilitation and inhibition at many levels of the CNS.     

CNS innervation of the urinary bladder demonstrated by immunohistochemical study for c-fos and pseudorabies virus

The aim of the present study is to verify the functional and anatomical neural pathways which innervate the urinary bladder in the central nervous system of the rat. To identify the functional neural pathway, the urinary bladder was stimulated by infusing formalin for 2 h. Then, brain and spinal cord were dissected out and immunohistochemistry was done by using anti-c-fos antibody. Many c-fos immunoreactive (IR) neurons were identified in the telencephalic cortical areas and in several brainstem nuclei, which are known mostly to be related with urinary bladder. In the spinal cord, a number of c-fos IR neurons were found in the lamina I, IIo, dorsal gray commissure, sacral parasympathetic nucleus. To identify the anatomical neural pathway of the urinary bladder, Pseudorabies virus (PRV) was injected into the wall of urinary bladder and was identified with anti-PRV by using immunohistochemistry. Most PRV labeled neurons were found where c-fos IR neurons were identified and few of them were also in the areas where c-fos IR neurons were not found, e.g., prefrontal cortex, agranular insular cortex, and subfornical organ. In the spinal cord, PRV labeled cells were found all over the gray matter. The present study presents morphological evidence demonstrating the supraspinal areas are related with the neural control of the urinary bladder and most functional neural pathway of the urinary bladder is well consistent with the anatomical neural pathway except in some telencephalic cortical areas.     

Failure to differentiate Cryptosporidium parvum from C. meleagridis based on PCR amplification of eight DNA sequences

PURPOSE: Little is known about the developmental effects of high urinary diversion and bladder defunctionalization in infancy. Although clinical experience shows that a poorly functional bladder may result from urinary diversion in infancy, the mechanisms of change and specific bladder wall alterations have not been well characterized. We hypothesized that cyclic filling and emptying are necessary for normal bladder development. To investigate this important question we created a new animal model. MATERIALS AND METHODS: We designed a new method of hemibladder urinary diversion in 3-week-old New Zealand white rabbits. After vertical midline bladder division half of the bladder was formed into a functional reservoir, which remained in continuity with the ipsilateral ureter and urethra. The other bladder half was defunctionalized and isolated from the urine flow by ureteral ligation. Diversion was created for 3, 7, 14 and 28 days. Urodynamic evaluation was done in the functionalized hemibladders and age matched normal rabbit bladders to test the validity of the functionalized hemibladder as an internal control. Functional and defunctionalized hemibladders as well as age matched, nonoperated normal rabbit bladders were weighed, sectioned and stained to demonstrate muscle and connective tissue components. RESULTS: In 22 of the 27 healthy rabbits (81%) good quality diverted and functional bladder specimens were obtained after diversion. Defunctionalized hemibladders grew more slowly than functionalized bladders and normal age matched control bladders. Histological staining of the bladder wall demonstrated increased connective tissue between the muscle bundles within the diverted specimens than in functional bladders. CONCLUSIONS: Our successful model of urinary diversion may be used to study the developmental and histological effects of urinary diversion in the young bladder. Bladder growth and histological appearance are altered when the stimulus of cyclic filling and emptying is removed. Further studies using this model are warranted to define fully bladder changes that result from diversion and investigate the mechanism of the observed changes.     

A new method for cytodestruction of bladder epithelium using protamine sulfate and urea

Bladder epithelium relies primarily on the presence of a surface glycosaminoglycan (GAG) layer and the structural integrity of cell-cell contact to maintain impermeability to toxic urinary wastes. Previous clinical studies evaluating bladder permeability characteristics in interstitial cystitis patients had indicated that epithelial desquamation occurs after treatment with protamine sulfate (PS) followed by hypertonic urea. The following study was performed using rabbits to further investigate this finding. The urinary bladder was evaluated for optimal treatment conditions for epithelial removal. Protamine sulfate (1 to 10 mg./ml.) and urea (100 to 200 gm./ml.) were instilled into the bladder at volumes ranging from 5 to 60 ml. to that required for near maximum distention. After incubation at room temperature for 15 minutes, the bladders were fixed and evaluated histologically for epithelial removal. The maximum epithelial removal occurred when the bladders were distended, and when PS concentration was 5 to 10 mg./ml. and urea at 200 gm./l. There was greater epithelium removal after repeated treatments. Epithelial cells that were removed were not viable based on Trypan blue staining. There was no significant increase of C14 labeled urea in the plasma after 15 minutes. Rabbits that were followed for 6 weeks after treatment did not show any histological evidence of increased collagen deposition and/or fibrosis. This procedure may have important clinical value since it may remove sufficient bladder epithelium in patients with transitional cell carcinoma to have therapeutic benefit. This offers a realistic option for selective, nontoxic destruction of bladder epithelium.     

Clinical and hormonal effects of the combination gonadotrophin-releasing hormone agonist plus oral contraceptive pills containing ethinyl-oestradiol (EE) and cyproterone acetate (CPA) versus the EE-CPA pill alone on polycystic ovarian disease-related hyperandrogenisms

This study examined how cyclophosphamide (CP)-induced cystitis related manifestations (bladder inflammation and behavioral impairment) differed in female and male Sprague-Dawley rats. Under transient halothane-O2-N2O gas anesthesia, a single dose of CP was injected (100 mg/kg i.p. in 1 ml saline) and the animal's behaviors analyzed for a period of 4 h using a protocol that permits quantitative analysis of behavioral impairment. The rats were then sacrificed and their bladders removed for histological quantification of inflammation. All CP-injected, but not control rats, exhibited a range of impairment behaviors that increased rapidly over a period of 2 h, gradually reaching plateau levels over the next 2 h. Female rats initially developed behavioral responses faster than male rats, but reached the same mean peak values overall as males. No sex differences were observed in CP-induced bladder inflammation. Influences of time-of-day and estrous stage were further examined in females. Time-of-day had no effect on the degree of bladder inflammation. Although there were also no significant time-of-day differences in behavioral impairments, impairment scores from 90 min after the injection consistently tended to be lower for rats injected 5 h versus 9 h after lights on. Overall, the effects of estrous stage were also insignificant. However, a subset of rats who were in the estrous stage of their cycle early in the morning of the experimental day developed the most severe degree of bladder inflammation, but failed to develop the severe behavioral impairments shown by all the other rats. These results show that there are seemingly only minor sex differences in the overall behavioral and inflammatory consequences of CP injections, as evidenced by similar final degrees of behavioral impairment and inflammation. These results also suggest, however, that there are sex differences in the etiology of the disease process. These differences are evidenced by the more rapid development of behavioral symptoms in females and the susceptibility of some of those having shown morning estrous smears to develop very severe bladder inflammation in absence of corresponding behavioral impairment. The multiple influences of sex and estrous condition on CP-induced cystitis related manifestations observed here underline the complexity of the etiological factors associated with the cystitis disease process.     

The role of nerve growth factor in a model of visceral inflammation

There is growing evidence that nerve growth factor may be an important mediator of the sensory disorders associated with inflammation. This hypothesis was tested in a rat model of cystitis. In this model, an experimental inflammation is created in anaesthetized rats with an irritant chemical. Within 1 h, bladder reflexes, activated by the sensory innervation of this viscus, become exaggerated, mimicking the disorders seen in humans with chronic cystitis. The development of this hyper-reflexia following experimental inflammation was quantified using the technique of repeated cystometrograms. By several measures, bladder reflex excitability increased about three-fold after 5 h. Firstly, the study investigated whether inflammatory changes can be prevented by pharmacological antagonism of nerve growth factor. A synthetic fusion protein was used, consisting of the extracelluar domain of the high-affinity nerve growth factor receptor, trkA, coupled to the Fc portion of an immunoglobulin. Previous work has shown that this molecule can sequester nerve growth factor and reduce its bioavailability both in vitro and in vivo. Treatment of animals with the fusion molecule at 1 mg/kg, immediately before inflammation of the bladder, largely, and very significantly, prevented the expected increases in reflex excitability of this organ. Pretreatment with a related fusion protein, capable of sequestering the neurotrophin brain-derived neurotrophic factor and neurotrophin-4/5, but not nerve growth factor, was without effect. Similarly, a control fusion molecule, without neurotrophin-sequestering capacity, did not reduce the inflammation-induced hyper-reflexia. Systemic treatment with the nerve growth factor-sequestering molecule, but not control molecules, partially and significantly reversed established inflammatory changes, by about 30-60%, depending on outcome measure. The nerve growth factor-sequestering protein had no significant effects on bladder reflex excitability in the uninflamed state. It was also without significant effect on capsaicin-induced contractions of the urinary bladder. Administration of exogenous nerve growth factor into the lumen of the urinary bladders of normal anaesthetized rats produced a rapid and marked bladder hyper-reflexia similar to that seen with experimental inflammation. These findings are consistent with other circumstantial evidence that nerve growth factor may interact with visceral sensory systems. Together, the data strongly suggest that nerve growth factor produced in inflamed tissues is a critical mediator of the sensory disorders associated with inflammation.     

Cancer of the bladder in spinal cord injury patients

Since 1963, 10 cases of bladder carcinoma have been detected in 1,052 new admissions to our center. A high percentage of these patients had squamous cell carcinoma and/or squamous elements. This relatively high incidence stimulated a prospective study of 81 spinal cord injury patients either maintained on intraurethral catheter drainage for 10 years or an external appliance for 15 years. There were changes of squamous metaplasia in 19 per cent of the cases but no cancer was detected. It remains undetermined if squamous metaplasia is a pre-malignant lesion. However, the incidence of squamous metaplasia and squamous cell carcinoma in paraplegics with chronically infected bladders is not uncommon. Any spinal cord injury patient with hematuria needs a complete bladder evaluation and any long-term paraplegic with chronic infection should undergo cystoscopy and Papanicolaou smears as part of the yearly checkup.     

The role of urinary potassium in the pathogenesis and diagnosis of interstitial cystitis

PURPOSE: We determined whether intravesical potassium absorption in normal bladders correlates with increased sensory urgency, and corroborated the hypothesis that mucus is important in the regulation of epithelial permeability. We compared sensory nerve provocative ability of sodium versus potassium, and determined whether intravesical potassium sensitivity discriminates patients with interstitial cystitis from normal subjects and those with other sensory disorders of the bladder. MATERIALS AND METHODS: A total of 231 patients with interstitial cystitis and 41 normal subjects underwent intravesical challenge with 40 ml. water and then 40 ml. of 40 mEq./100 ml. potassium chloride. Subjective responses of urgency or pain stimulation were recorded on a scale of 0 to 5. In 19 normal subjects potassium absorption was measured at baseline, after injury of the bladder mucus with protamine, after heparin treatment to reverse mucus damage and then for a final time. These subjects simultaneously recorded the symptoms of sensory urgency and pain at baseline, after protamine and after heparin. Another group of normal volunteers underwent a challenge with sodium versus potassium to determine which cation was more provocative. Patients with bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH), detrusor instability, and acute and chronic urinary tract infection but no current infection were also evaluated for potassium sensitivity. RESULTS: Neither normal subjects nor patients with interstitial cystitis reacted to water administered intravesically. There was marked sensitivity to intravesical potassium in 75% of patients with interstitial cystitis versus 4% of controls (p <0.01). Only 1 patient with BPH responded to potassium and none of the 5 with chronic urinary tract infection responded. All 4 patients (100%) with a current acute urinary tract infection reacted positively to the potassium challenge. Of 16 patients with detrusor instability 25% responded. Normal subjects had minimal sensitivity to potassium before (11%) and markedly increased sensitivity after (79%) protamine treatment, and these symptoms were reversed by heparin in 42%. Potassium absorption directly correlated with symptoms (0.4, 3.0 and 1.3 mEq. before and after protamine, and after heparin reversal, respectively). In regard to sodium versus potassium provocation, potassium was far more provocative for causing urgency after protamine (10 versus 90%). Neither group underwent provocation before protamine. CONCLUSIONS: Chronic diffusion of urinary potassium into the bladder interstitium may induce sensory symptoms, damage tissue and be a major toxic factor in the pathogenesis of interstitial cystitis. Intravesical potassium sensitivity is a reliable method for detecting abnormal epithelial permeability. It discriminates between patients with interstitial cystitis and normal subjects with intact epithelial function, and it is a useful diagnostic test for interstitial cystitis. Potassium sensitivity correlates with increased potassium absorption in normal subjects, and potassium is far more provocative than sodium. Potassium sensitivity is also present in acute urinary tract infection and occasionally detrusor instability but not in BPH or chronic urinary tract infections.     

Regulating the balance between differentiation and apoptosis: role of CREM in the male germ cells

Axon regeneration fails in the CNS because the glial environment is inhibitory, and because the regenerative response of CNS is poor. Regeneration can therefore be induced by removing the inhibitory effect of CNS glial molecules, by increasing the regenerative in animal models of spinal cord injury has recently been achieved by several strategies that apply these principles. The successful techniques have been to block inhibitory molecules made by astrocytes, to implant peripheral nerve grafts embedded in a bFGF-containing fibrin gel, to implant olfactory ensheathing cells, to graft embryonic spinal cord tissue, and to implant trophic factor-secreting fibroblasts. The next challenge is to prepare to apply these types of treatment to human patients with spinal cord injuries.     

High affinity binding sites for [3H]substance P in urinary bladders of cats with interstitial cystitis

PURPOSE: Pain is a common feature of interstitial cystitis (IC). Although the effects of IC on sensory neuron density have been investigated, its influence on substance P receptor (SPR) numbers and function are not well known. To evaluate the role of SPR in cats with IC, we measured the affinity (Kd), numbers (Bmax), and substrate specificity of binding sites for [3H]SP in urinary bladders of healthy cats and cats suffering from IC. MATERIALS & METHODS: Radioligand binding assays of cat and rat brain, normal cat bladders, and inflamed bladders from cats diagnosed with IC were conducted using [3H]SP to determine SPR affinity and numbers. Binding sites for [125I]SP were identified using autoradiography in slide-mounted frozen tissue sections, and their specificity determined with competition binding studies. RESULTS: In bladder homogenate binding studies, low affinity SP binding sites for [3H]SP were found both in normal and inflamed tissue, whereas high affinity binding sites were found in inflamed bladder tissue only. Based on autoradiographic studies, high affinity binding appeared to be to small blood vessels, and to be specific for substance P, a pharmacology consistent with the neurokinin-1 receptor (NK1R). CONCLUSIONS: Upregulation of NK1R may be part of the pathophysiology of IC, as it is in some other inflammatory diseases. If so, more specifically targeted therapies for IC may become available.     

Effect of naloxone on the bladder activity of rabbits with acute spinal injury

BACKGROUND: Naloxone enhances bladder activity in patients with chronic spinal cord injury. However, there are few reports on naloxone for bladder morbidity in acute spinal cord injury. METHODS: We performed a prospective, controlled study of the effects of naloxone on bladder function in rabbits with and without surgical transection of the spinal cord at the 10th thoracic vertebra. Acute and chronic stages of injury were defined according to bladder function. Naloxone was given intravenously at both stages, and intrathecally at the acute stage. Bladder activity was monitored by cystometry. Blood concentrations of methionine-enkephalin were measured by radioimmunoassay. RESULTS: Spinal cord injuries were acute 1 or 2 days after surgery, and chronic after 1 or 2 weeks. Bladder capacity significantly decreased after 0.01 mg of intravenous naloxone in uninjured control rabbits, and after 0.03 mg of intravenous naloxone in rabbits with chronic-phase injuries. During the acute-injury phase, 0.3 mg of intravenous naloxone, or 0.02 mg of intrathecal naloxone, was necessary to evoke the micturition reflex. No significant changes in blood enkephalin levels were seen before or after spinal cord injury. CONCLUSION: In rabbits with acute spinal cord injury, intrathecal naloxone evoked the micturition reflex at a much lower dose than did intravenous naloxone. Intrathecal naloxone promises to become a new therapy for the acute stage of spinal cord injury for active recovery of bladder function, and could replace current therapy.     

Detection of eubacteria in interstitial cystitis by 16S rDNA amplification

OBJECTIVE: To determine what role non-culturable microorganisms play in the etiology of interstitial cystitis (IC). MATERIALS AND METHODS: Thirty patients fulfilling NIH criteria for the diagnosis of interstitial cystitis and sixteen control patients with culture negative urine gave written informed consent and underwent bladder biopsy. Polymerase chain reaction (PCR) using two sets of universal primers for bacterial 16S rDNA was performed on urine from the cystoscope and on a cold cup bladder biopsy specimen. Of the PCR positive bladder biopsies, three patients with interstitial cystitis and three controls were randomly selected and cloned. Ten clones from each were sequenced and putative taxonomic assignments made. RESULTS: 12/26 (46%) IC and 5/12 (42%) control urine specimens and 16/30 (53%) and 9/15 (60%) bladder biopsies were PCR positive, respectively. The bacterial populations in the two patient groups tested appeared to be different based upon analysis of the 16S rRNA sequences. CONCLUSIONS: Both IC and control patients had non-culturable bacteria in their bladders. A random sampling of the two populations revealed that the bacterial populations are different, suggesting a possible link between one or more bacterial species and IC.     

Detrusor myopathy: an accurate predictor of bladder hypocompliance and contracture in interstitial cystitis

OBJECTIVE: To determine whether any histological characteristics within the detrusor in cases of early interstitial cystitis (IC) predict the subsequent development of severe symptoms due to bladder contracture. PATIENTS AND METHODS: The detrusor muscle component of bladder biopsies from 21 patients with IC was examined in sections stained with haematoxylin and eosin. Videocystometrography was performed at least 2 months after the biopsy and the patients were then followed up clinically for at least 3 years. RESULTS: The detrusor appeared normal in 13 patients; in eight there was evidence of detrusor myopathy. Patients with biopsies confirming detrusor myopathy were significantly more likely to have hypocompliant bladders than those with normal detrusor muscle histology (P < 0.02). Over the following 3 years, six of the eight patients with detrusor myopathy developed progressively severe symptoms and required subtotal cystectomy and enterocystoplasty. None of the 13 patients without detrusor myopathy required bladder substitution. CONCLUSION: In IC, detrusor myopathy is associated with bladder hypocompliance. Patients with detrusor myopathy appear to have more severe disease and are more likely to progress to bladder contracture requiring substitution enterocystoplasty.     

Post radiation hemorrhagic cystitis: MR findings

We report on the magnetic resonance findings in two patients with hemorrhagic cystitis secondary to radiation therapy. One patient's bladder wall was high in signal intensity on T1-weighted fat-suppressed spoiled gradient echo and low in signal intensity on T2-weighted fat-suppressed spin echo images, findings consistent with intracellular methemoglobin in the setting of subacute intramural hemorrhage. The second patient's bladder wall had regions that were low in signal intensity on T1-weighted fat-suppressed spin echo and high in signal intensity on T2-weighted fat-suppressed spin echo, and other regions that were high in signal intensity on T1-weighted fat suppressed spin echo and on T2-weighted fat-suppressed spin echo images, findings that were consistent with active bleeding and late subacute hemorrhage, respectively. Imaging findings correlated with the patients' clinical picture. Our two cases illustrate that magnetic resonance images may demonstrate changes of hemorrhagic cystitis and may permit determination of disease acuity.     

Central and peripheral actions of the NSAID ketoprofen on spinal cord nociceptive reflexes

Ketoprofen is a non-steroidal antiinflammatory drug (NSAID) which provides effective analgesia in situations of pain provoked by tissue inflammation. However, the location of its analgesic effects, (peripheral tissues versus central nervous system), have not been clearly identified and separated. In the present study the effectiveness of ketoprofen was examined in two different types of experiments: (i) Open field behavioural tests in conscious rats, and (ii) spinal cord nociceptive reflexes (single motor units) activated by electrical and thermal stimulation in chloralose anaesthetised rats. The experiments were performed in rats with carrageenan-induced inflammation of one hindpaw, or of one knee joint. The administration of ketoprofen significantly inhibited the reduction of exploratory movements caused by inflammation in open field experiments. Ketoprofen was also effective in depressing reflex activity evoked by electrical and noxious thermal stimulation of the skin, either in inflamed tissue or in normal tissue of monoarthritic animals. It was also effective in the reduction of reflex wind-up; a phenomenon in which the activity of spinal cord neurones increases progressively with high frequency electrical stimulation. We therefore conclude that ketoprofen has central as well as peripheral analgesic activity.     

Acupuncture for urinary incontinence in patients with chronic spinal cord injury. A preliminary report

PURPOSE: We investigated the possible use of acupuncture for the treatment of urinary incontinence caused by detrusor hyperflexia in patients with chronic spinal cord injury. METHOD: A total of 8 male chronic spinal cord injured patients with urinary incontinence were treated by acupuncture. Their ages ranged from 20 to 33 years (mean 27). The level of lesion was cervical in 4 and thoracic in 4. Detrusor hyperreflexia with uninhibited bladder contraction was confirmed by urodynamic studies in all of them. Acupuncture was performed using a disposable stainless needle (0.3 mm in diameter, 60 mm in length), which was inserted into bilateral BL-33 (Zhongliao) points and was rotated manually for 10 minutes. The treatment was conducted every week for 4 weeks. Urodynamic studies were repeated, immediately after the beginning of and a week after the completion of the treatment. Urinary symptoms were also checked before and after the treatment. RESULTS: No side effects were recognized throughout the treatment period. Among 8 patients, incontinence was controlled completely in 3 (38%) and partially in 3 (38%). The average maximum cystometric bladder capacity increased significantly, from 42.3 +/- 37.9 ml to 148.1 +/- 101.2 ml by the treatment (p < 0.05), while the average maximum bladder pressure was not changed. CONCLUSIONS: These data suggest that acupuncture could be a promising alternative for conventional therapies for urinary incontinence caused by detrusor hyperreflexia in patients with chronic spinal cord injuries.     

Cytoskeletal and cytocontractile protein composition of smooth muscle cells in developing and obstructed rabbit bladder

The differentiation patterns of smooth muscle cells (SMC) in rabbit bladder during development and in the hypertrophic response to partial outflow obstruction induced in adult animals were evaluated by biochemical and immunochemical techniques and by using a panel of monoclonal antibodies specific for desmin, vimentin, alpha-actin of smooth muscle (SM) type, SM myosin, and nonmuscle (NM) myosin isoforms. Desmin and SM alpha-actin were homogeneously distributed in SMC of developing, adult, and obstructed bladders. Conversely, marked changes in the ratio and antigenicity of SM myosin isoforms were observed by SDS electrophoresis and Western blotting, respectively. In particular, the 205 K (SM1) isoform was down-regulated with development whereas the 200 K (SM2) isoform was up-regulated around 7 days after birth and down-regulated in the obstructed bladder. Vimentin was expressed in SMC of the fetal bladder and declined markedly during postnatal, physiological hypertrophy of SMC, which occurs concomitantly with diminution of DNA synthesis. This polypeptide became detectable, however, in SMC of obstructed bladders. The 196 K (NM) myosin isoform recognized by NM-A9 antibody, present only in endothelium of blood vessels and in mucosa of normal fetal and adult bladders, became expressed in detrusor muscle, when SMC underwent a process of pathological hypertrophy. The reexpression of vimentin and the de novo appearance of NM myosin isoform in hypertrophic bladders can be reversed when the tissue mass is reduced, such as in bladders after 1-month recovery from partial obstruction. Thus, a specific NM myosin isoform can be used as a marker of SMC hypertrophy in obstructed bladder. In addition, the combined use of anti-vimentin and NM-A9 antibodies can distinguish between SMC which are in the physiological or in the pathological condition of adaptive bladder hypertrophy.     

Activated macrophages and the blood-brain barrier: inflammation after CNS injury leads to increases in putative inhibitory molecules

The cellular responses to spinal cord or brain injury include the production of molecules that modulate wound healing. This study examined the upregulation of chondroitin sulfate proteoglycans, a family of molecules present in the wound healing matrix that may inhibit axon regeneration in the central nervous system (CNS) after trauma. We have demonstrated increases in these putative inhibitory molecules in brain and spinal cord injury models, and we observed a close correlation between the tissue distribution of their upregulation and the presence of inflammation and a compromised blood-brain barrier. We determined that the presence of degenerating and dying axons injured by direct trauma does not provide a sufficient signal to induce the increases in proteoglycans observed after injury. Activated macrophages, their products, or other serum components that cross a compromised blood-brain barrier may provide a stimulus for changes in extracellular matrix molecules after CNS injury. While gliosis is associated with increased levels of proteoglycans, not all reactive astrocytes are associated with augmented amounts of these extracellular matrix molecules, which suggests a heterogeneity among glial cells that exhibit a reactive phenotype. Chondroitin sulfate also demarcates developing cavities of secondary necrosis, implicating these types of boundary molecules in the protective response of the CNS to trauma.     

Enhancement of rat urinary bladder tumorigenesis by lipopolysaccharide-induced inflammation

Chronic inflammation of the urinary tract is a significant risk factor for the development of urinary bladder cancer in humans. We previously demonstrated that weekly treatment with killed Escherichia coli enhanced rat urinary bladder tumorigenesis initiated by the carcinogen N-methyl-N-nitrosourea. We conducted the present study to determine whether lipopolysaccharide (LPS), a major cell wall component of E. coli, had a tumor-enhancing effect. LPS was instilled twice a week at three doses (100, 1.0, and 0.01 microgram/ml) into heterotopically transplanted rat urinary bladders which were treated with a single low dose (0.25 mg) of N-methyl-N-nitrosourea or vehicle. Rats treated with 100 micrograms/ml of LPS showed a significant increase in the incidence and number of tumors in the bladders pretreated with N-methyl-N-nitrosourea. Treatment with LPS alone did not induce tumors. The enhancing effects were associated with a marked increase in the numbers of polymorphonuclear leukocytes and an increase in the H2O2 concentration in the bladder lumen. Oxidative stress by reactive oxygen intermediates and a proliferative response of the carcinogen-exposed urothelium to the inflammatory stimulation appeared to play a significant role in tumor enhancement by LPS.