MDS-Related Anemia Is Associated with Impaired Quality of Life but Improvement Is Not Always Achieved by Increased Hemoglobin Level

Quality of life is impaired in MDS, but the role of hemoglobin level is unclear. To study the Hb-QoL correlation at diagnosis and 1 year later, patients filled out the EQ-5D questionnaire, assessing their mobility, self care, daily activities, pain/discomfort, and anxiety/depression, using scores of 0 (normal), 1 (mild/moderate), or 2 (poor). They also evaluated their health using a visual analogue scale, scoring from 0 (poor) to 100 (excellent). The anemia subgroups were: none/normal (Hb ≥ 12.5 g/dL), mild (10 ≤ Hb < 12.5), moderate (9 ≤ Hb < 10), severe (8 ≤ Hb < 9), or very severe (Hb < 8). LR-MDS patients (n = 127) and inpatient controls (n = 141) participated. The anemic patients had a poor QoL and the MDS patients had a lower QoL with a lower Hb. The controls had no QoL difference among the various anemia subgroups. In addition, the MDS QoL sharply decreased with an Hb of < 9. The MDS patients showed a wide QoL variability, i.e., different QoL scores in the same Hb subgroup, suggesting that other factors affect QoL (e.g., age and comorbidities). After 1 year (n = 61), the QoL was still poor for most MDS patients (including 27 patients with an increased Hb). In summary: (1) a poor QoL in MDS-anemia is non-linear, suggesting other influencing factors on QoL. (2) The sharp QoL drop with Hb < 9 g/dL challenges the transfusion Hb threshold. (3) The QoL in anemic MDS patients might differ from that in non-MDS patients. (4) Raising Hb, while recommended, does not guarantee an improved QoL.

Clonal Myeloid Dysplasia Following CAR T-Cell Therapy: Chicken or the Egg?

Multiple myeloma (MM) is characterized by recurrent relapses. Consequently, patients receive multiple therapy lines, including alkylating agents and immune modulators, which have been associated with secondary malignancies such as myelodysplastic syndrome (MDS). Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T cell (CART) therapy is efficacious in patients with relapsed/refractory (R/R) MM. However, the long-term complications, particularly MDS, are not well understood. Whether CART therapy causes or promotes MDS has not been thoroughly investigated. In this study, we explored the causal relationship between MDS and CART therapy. We retrospectively examined the prevalence of MDS-related morphological and mutational changes before and after administration of CART therapy in five patients. Among them, four developed MDS after CART therapy, while one had pre-existing MDS prior to CART. None of the four patients who developed post-CART MDS showed morphological MDS changes prior to CART therapy. However, all four patients exhibited molecular alterations associated with MDS in their pre-CART as well as post-CART therapy bone marrow. No new mutations were observed. Our findings provide initial evidence suggesting that anti-BCMA CART therapy in MM may promote expansion of pre-existing MDS clones rather than causing development of new clones.

Risk factors and outcomes of COVID-19 in adult patients with hematological malignancies: A single-center study showing lower than expected rates of hospitalization and mortality

BACKGROUND

Studies addressing coronavirus disease 2019 (COVID-19) in patients with hematological malignancies have reported mortality rates of up to 40%; however, included predominantly hospitalized patients.

METHODS

During the first year of the pandemic, we followed adult patients with hematological malignancies treated at a tertiary center in Jerusalem, Israel, who contracted COVID-19, with the aim of studying risk factors for adverse COVID-19-related outcomes. We used remote communication to track patients managed at home-isolation, and patient questioning to assess the source of COVID-19 infection, community versus nosocomial.

RESULTS

Our series included 183 patients, median age was 62.5 years, 72% had at least one comorbidity and 39% were receiving active antineoplastic treatment. Hospitalization, critical COVID-19, and mortality rates were 32%, 12.6%, and 9.8%, respectively, remarkably lower than previously reported. Age, multiple comorbidities, and active antineoplastic treatment were significantly associated with hospitalization due to COVID-19. Treatment with monoclonal antibodies was strongly associated with both hospitalization and critical COVID-19. In older (≥60) patients not receiving active antineoplastic treatment, mortality, and severe COVID-19 rates were comparable to those of the general Israeli population. We did not detect patients that contracted COVID-19 within the Hematology Division.

CONCLUSION

These findings are relevant for the future management of patients with hematological malignancies in COVID-19-affected regions.

Desensitization protocol to lenalidomide: An effective and safe treatment modality for delayed hypersensitivity-induced rash in patients with multiple myeloma

INTRODUCTION AND OBJECTIVES

Lenalidomide is considered a standard of care in multiple myeloma (MM) Some MM patients will develop delayed hypersensitivity to lenalidomide, which can lead to treatment discontinuation. Desensitization to lenalidomide can help these patients to complete treatment courses. Here, we aimed to review lenalidomide-treated MM patients who developed delayed hypersensitivity-induced rash and were treated with desensitization.

METHODS

A retrospective analysis of medical files of MM patients, who were desensitized to lenalidomide due to delayed hypersensitivity rash. Patients were treated between 2018 and 2022 at Hadassah Medical Center, Jerusalem, Israel.

RESULTS

Search of patients yielded 16 patients that underwent desensitization to lenalidomide within the study period. The desensitization protocol consisted of a slow, 3-week-long protocol with lenalidomide's target doses of 10, 15, and 25 mg/day. Of the 16 patients, 10 (62.5%) succeeded to complete the protocol and thus were able to complete lenalidomide treatment cycles. One patient with unsuccessful desensitization was subsequently treated with first-generation IMiD thalidomide, with no rash appearing. None of the patients that were treated with desensitization had severe immune-mediated or non-dermatological adverse reactions.

CONCLUSIONS

Desensitization to lenalidomide is safe and effective. Discontinuation of lenalidomide in MM patients with delayed hypersensitivity and no contraindication to desensitization should be discouraged. Collaboration between hematologists and allergists is needed.

Monitoring Minimal Residual Disease in RUNX1-Mutated Acute Myeloid Leukemia

INTRODUCTION

Mutated RUNX1 is considered a poor prognostic factor and usually is mutually exclusive with NPM1 mutations. Monitoring of molecular markers for minimal residual disease provides a powerful tool to assess remission and guide clinical decisions.

METHODS

Newly diagnosed RUNX1-mutated AML patients, designated to intensive chemotherapy-based treatment or nonintensive regimens, were monitored for mutated RUNX1 transcript levels by qPCR with patient-specific primers. Samples were obtained along the treatment course and follow-up.

RESULTS

A clear correlation was observed between mutated RUNX1 levels and response to treatment as observed by flow cytometry and STR-based assessment.

CONCLUSION

We demonstrate the feasibility of RUNX1-based MRD to correlate with the clinicopathological status of leukemia. We further suggest how RUNX1 qPCR monitoring can influence clinical decision-making and contribute to improved personalized patient care.

Romidepsin-Bendamustine Combination for Relapsed/Refractory T Cell Lymphoma

BACKGROUND

The treatment of relapsed/refractory (R/R) peripheral T cell lymphoma (PTCL) is limited to a few agents. Romidepsin, a histone deacetylase inhibitor, was approved for PTCL treatment as a single agent in the R/R setting, yet with partial efficacy. Several attempts to combine romidepsin with other chemotherapy regimens have been reported, however, with significant toxicity.

OBJECTIVES

To study the romidepsin-bendamustine combination in PTCL in an attempt to maximize efficacy while minimizing toxicity.

METHODS

We report on a series of 7 heavily pretreated PTCL patients (2-5 previous lines of therapy) treated with a romidepsin-bendamustine combination.

RESULTS

Four patients were not previously exposed to either drug. Of these, 2 achieved complete remission. Interestingly, 1 patient continued treatment with a prolonged progression-free survival of more than 4 years. Toxicity was minimal and no treatment-related deaths or discontinuation were noted. Significant nausea and vomiting were reported in over 50% of patients. Hematological toxicity was mild and lower than that reported for other romidepsin-chemotherapy combinations and was correlated with bone marrow involvement by lymphoma.

CONCLUSIONS

Although reporting a small number of patients, our data suggest that the combination of romidepsin and bendamustine may be a feasible therapeutic option in R/R PTCL patients and merits further study.

Prospective comparison of early bone marrow evaluation on day 5 versus day 14 of the "3 + 7" induction regimen for acute myeloid leukemia

Evaluation of early response during induction therapy for acute myeloid leukemia (AML) is used for prognostication and re-induction strategy, yet the optimal evaluation time point is unknown. Clearance of bone marrow (BM) blasts by day 14 of therapy does not ensure remission; thus, some patients requiring re-induction are neglected. This study aimed to examine the role of earlier BM evaluation during induction for predicting remission and overall survival. Results of BM testing on the 5th and 14th day of intensive induction were prospectively compared in 127 adult patients with AML. Re-induction was given, based on Day 14 results, to 25 patients. Reduction of the BM blast count to <5% as early as by the fifth day of induction was more specifically associated with the achievement of remission compared to Day 14 (88.2% vs. 60%, respectively). Rapid responders have a better 3-year overall survival (OS). Day 5 results are a stronger predictor of OS by multivariate analysis and better segregate long-term survivors than the Day 14th BM count (66% vs. 30%, P = 0.0001 and 48% vs. 37%, respectively, P = 0.04). The Day 5 evaluation of BM carries significant clinical information. The benefit of prescribing re-induction based on such early evaluation should be prospectively studied.

Valorisation of electric arc furnace steel slag as raw material for low energy belite cements

In this paper, the valorisation of electric arc furnace steel slag (EAFS) in the production of low energy belite cements is studied. Three types of clinkers were prepared with 0 wt.% (BC), 5 wt.% (BC5) and 10 wt.% (BC10) EAFS, respectively. The design of the raw mixes was based on the compositional indices lime saturation factor (LSF), alumina ratio (AR) and silica ratio (SR). The clinkering temperature was studied for the range 1280-1400°C; firing was performed at 1380°C based on the results regarding free lime and the evolution of microstructure. In order to activate the belite, clinkers were cooled fast by blown air and concurrent crushing. The results demonstrate that the microstructure of the produced clinkers is dominated by belite and alite crystals, with tricalcium aluminate and tetracalcium-alumino-ferrite present as micro-crystalline interstitial phases. The prepared cements presented low early strength development as expected for belite-rich compositions; however the 28-day results were 47.5 MPa, 46.6 MPa and 42.8 MPa for BC, BC5 and BC10, respectively. These values are comparable with OPC CEMI 32.5 N (32.5-52.5 MPa) according to EN 197-1. A fast setting behaviour was also observed, particularly in the case of BC10, whereas soundness did not exceed 1mm.

LPS-sensory peptide communication in experimental cystitis

Stimulation of sensory nerves can lead to release of peptides such as substance P (SP) and consequently to neurogenic inflammation. We studied the role of bacterial lipopolysaccharide (LPS) in regulating SP-induced inflammation. Experimental cystitis was induced in female mice by intravesical instillation of SP, LPS, or fluorescein-labeled LPS. Uptake of fluorescein-labeled LPS was determined by confocal analysis, and bladder inflammation was determined by morphological analysis. SP was infused into the bladders of some mice 24 h after exposure to LPS. In vitro studies determined the capacity of LPS and SP to induce histamine and cytokine release by the bladder. LPS was taken up by urothelial cells and distributed systemically. Twenty-four hours after instillation of LPS or SP, bladder inflammation was characterized by edema and leukocytic infiltration of the bladder wall. LPS pretreatment enhanced neutrophil infiltration induced by SP, increased in vitro release of histamine, tumor necrosis factor-alpha, and interferon-gamma, and significantly reduced transforming growth factor-beta1 release. These findings suggest that LPS amplifies neurogenic inflammation, thereby playing a role in the pathogenesis of neurogenic cystitis.

[An anatomical curiosity: a miniature cranium in marble, pathological evidence?]

After a detailed historical review of the representation of the human skull in art, the authors present a rare example of a reduced marble skull representing as they suggest it, cranio-facial lesions of which they try to explain the etiopathology.

[The anatomy collections of the Paris V University: their role in medical teaching for two centuries]

The Museum of anatomy of the University Paris V exhibits a collection of ancient and high quality dissections and waxworks, very well preserved, which were used for teaching anatomy and have been classified historic monument since 1992.

Mast cell regulation of inflammation and gene expression during antigen-induced bladder inflammation in mice

Mast cell numbers are significantly increased in bladder disorders including malignancy and interstitial cystitis, but their precise role has been difficult to determine. We characterized the role of mast cells on gene regulation associated with antigen-induced bladder inflammation in mice. For this purpose, we examined the responses in mast cell-deficient (Kit(W)/Kit(W-v)), congenic normal (+/+), and Kit(W)/Kit(W-v) mice that were reconstituted with bone marrow stem cells (BMR) to restore mast cells. All mice were actively sensitized and challenged intravesically with either saline or specific antigen. Bladder inflammation occurred in +/+ and BMR but not the Kit(W)/Kit(W-v) mice. Gene expression was determined using mouse cDNA expression arrays. Self-organizing maps, performed without preconditions, indicated gene expression changes dependent on the presence of mast cells. These genes were upregulated in bladders isolated from antigen challenge of +/+, not altered in Kit(W)/Kit(W-v), and were upregulated in BMR mice. Taken together these results demonstrate an important role for mast cells in allergic cystitis and indicate that mast cells can alter their environment by regulating tissue gene expression.

In vitro contractile effects of neurokinin receptor blockade in the human ureter

PURPOSE

We identified the predominance of neurokinin-2 receptors and evaluated the inhibition of spontaneous contraction via the blockade of neurokinin-2 receptors in human ureteral segments.

MATERIALS AND METHODS

Excess ureteral segments from human subjects undergoing donor nephrectomy or reconstructive procedures were suspended in tissue baths containing Krebs buffer. After spontaneous contractions were recorded, tissues were incubated with 1 microM. solutions of phosphoramidon and captopril (to inhibit peptide degradation) and either the neurokinin-1 receptor antagonist CP 99,994, the neurokinin-2 receptor antagonist SR 48,968, the neurokinin-3 receptor antagonist SR 142,801 or dimethyl sulfoxide (control) for 1 hour. Contraction magnitude and frequency were again recorded and compared with spontaneous levels. Concentration-response curves to the tachykinins substance P, and neurokinins A and B were determined in the presence and absence of antagonists.

RESULTS

Neurokinin A increased contractility at lower concentrations than substance P or neurokinin B (p <0.013). Neurokinin-2 receptor blockade produced a 100-fold rightward shift of the concentration-response curves (p <0.013), while neurokinins 1 and 3 receptor blockade had no effect. SR 48,968 significantly reduced contractility during the 1-hour incubation period, causing a 97% reduction in spontaneous rates compared with a 29% reduction in control tissues. CP 99,994 and SR 142,801 had no significant effect.

CONCLUSIONS

Neurokinin-2 is the predominant receptor subtype responsible for tachykinin induced contraction of human ureteral smooth muscle. In vitro treatment with the neurokinin-2 antagonist SR 48,968 reduces the spontaneous contraction rate by 97% in vitro. Neurokinin-2 receptor antagonists may have clinical applications for ureteral disease.

Time course of LPS-induced gene expression in a mouse model of genitourinary inflammation

In this study, self-organizing map (SOM) gene cluster techniques are applied to the analysis of cDNA microarray analysis of gene expression changes occurring in the early stages of genitourinary inflammation. We determined the time course of lipopolysaccharide (LPS)-induced gene expression in experimental cystitis. Mice were euthanized 0.5, 1, 4, and 24 h after LPS instillation into the urinary bladder, and gene expression was determined using four replicate Atlas mouse cDNA expression arrays containing 588 known genes at each time point. SOM gene cluster analysis, performed without preconditions, identified functionally significant gene clusters based on the kinetics of change in gene expression. Genes were classified as follows: 1) expressed at time 0; 2) early genes (peak expression between 0.5 and 1 h); and 3) late genes (peak expression between 4 and 24 h). One gene cluster maintained a constant level of expression during the entire time period studied. In contrast, LPS treatment downregulated the expression of some genes expressed at time 0, in a cluster including transcription factors, protooncogenes, apoptosis-related proteins (cysteine protease), intracellular kinases, and growth factors. Gene upregulation in response to LPS was observed as early as 0.5 h in a cluster including the interleukin-6 (IL-6) receptor, alpha- and beta-nerve growth factor (alpha- and beta-NGF), vascular endothelial growth factor receptor-1 (VEGF R1), C-C chemokine receptor, and P-selectin. Another tight cluster of genes with marked expression at 1 h after LPS and insignificant expression at all other time points studied included the protooncogenes c-Fos, Fos-B, Fra-2, Jun-B, Jun-D, and Egr-1. Almost all interleukin genes were upregulated as early as 1 h after stimulation with LPS. Nuclear factor-kappaB (NF-kappaB) pathway genes collected in a single cluster with a peak expression 4 h after LPS stimulation. In contrast, most of the interleukin receptors and chemokine receptors presented a late peak of expression 24 h after LPS coinciding with the peak of neutrophil infiltration into the bladder wall. Selected cDNA microarray observations were confirmed by RNase protection assay. In conclusion, the cDNA array experimental approach provided a global profile of gene expression changes in bladder tissue after stimulation with LPS. SOM techniques identified functionally significant gene clusters, providing a powerful technical basis for future analysis of mechanisms of bladder inflammation.

CLA reduces antigen-induced histamine and PGE(2) release from sensitized guinea pig tracheae

Conjugated linoleic acid (CLA) has been shown to enhance immune reactions such as lymphocyte blastogenesis and delayed-type hypersensitivity. We investigated the role of CLA in type I (immediate) hypersensitivity, using a guinea pig tracheal superfusion model for measuring antigen-induced airway smooth muscle contraction and inflammatory mediator release. Female Hartley guinea pigs were fed a diet supplemented with 0.25 g corn oil or linoleic acid/100 g of diet (control) or 0.25 g CLA/100 g of diet for at least 1 wk before and during active sensitization to ovalbumin antigen. Tracheae from sensitized guinea pigs were suspended in air-filled water-jacketed (37 degrees C) tissue chambers in a superfusion apparatus. Tracheae were superfused with buffer containing antigen, and tissue contraction was recorded. Superfusate was collected at 90-s intervals for evaluation of histamine and PGE(2) release. CLA did not affect antigen-induced tracheal contractions when expressed as gram contraction per gram tissue. CLA significantly reduced antigen-induced histamine and PGE(2) release. CLA appears to decrease release of some inflammatory mediators during type I hypersensitivity reactions.

Neurogenic vasoreactivity of human internal thoracic artery is unaffected by endothelial cell integrity

BACKGROUND

The role of internal thoracic artery (ITA) nervous supply has not been previously considered as a potential factor influencing excellent long-term patency of an ITA graft. To define the interaction between the primary afferent neurons and endothelial cells of ITA, we investigated the effects of acute capsaicin administration in vitro on the isometric tension of human ITAs.

METHODS

Vessels were obtained from patients undergoing coronary bypass or from multi-organ transplant donors. Thirty-three ITA segments (5 mm wide) were suspended as rings between two stainless-steel stir-ups in water-jacketed (37 degrees C) tissue baths. The tissue baths contained 10 ml physiological salt solution (PSS) of the following composition (mM/L): NaCl 119, KCl 4.7, NaH2PO4 1.0, MgCl2 0.5, CaCl2 2.5, NaHCO3 25, and glucose 11, aerated continuously with 95% O2 and 5% CO2. Peptidase inhibitors, phosphoramidon (1 microM) and captopril (1 microM), were added to PSS to decrease peptide degradation. Mechanical responses were measured isometrically and recorded on a polygraph via isometric force transducers. Vessels were preconstricted with submaximal concentrations of norepinephrine. After the tension had stabilized, capsaicin was added cumulatively to the tissue bath. The viability of ITA was verified by its responses to endothelial-dependent (acetylcholine, 1 microM) (n=20) and endothelial-independent (sodium nitroprusside, 10 microM) (n=13) vasodilators.

RESULTS

The exposure of capsaicin (3 microM) to human ITA produced varied effects on ITA irrespective of its endothelium. Capsaicin induced contraction of the ITA smooth muscle in 13 endothelium-intact ITA segments while it produced vasoconstriction in 9 endothelium-denuded ITAs (p=0.6437). In response to capsaicin, relaxation of ITA smooth muscle was observed in 7 ITA rings with endothelium, while vasodilation was present in 4 ITA segments without endothelium (p=0.4099).

CONCLUSIONS

Capsaicin-sensitive neurons encircling human ITA produce a neurogenic vasoreactive response independent of ITA endothelial cell integrity.

Determination of mouse bladder inflammatory response to E. coli lipopolysaccharide

Evaluation of the severity of histologic changes associated with cystitis is often subjective and inconsistent from one sample to the next. The objective of this study was to establish a consistent, reproducible method to quantify histologic changes in a mouse model of lipopolysaccharide (LPS)-induced cystitis. Either LPS (n = 8) or pyrogen-free saline (n = 8) was instilled intravesically into the bladders of female C57bk-6 J mice. Twenty-four hours later, mice in these groups as well as eight untreated controls were sacrificed and bladders were removed, fixed in formalin, and stained with hematoxylin and eosin (H&E). A bladder inflammatory index (BII) was described by reviewing tissues for edema, leukocyte infiltration, and hemorrhage. Cross-sections were evaluated by a single pathologist in a blinded manner based on the objective BII described. The BII method for objectively analyzing bladder inflammation was effective and reproducible. Bladders instilled with LPS had significantly increased inflammation scores for edema, leukocyte infiltration, and hemorrhage compared with those instilled with saline or untreated controls (n = 8, P < 0.05). These results demonstrate that LPS causes bladder inflammation when instilled intravesically and that inflammation of mouse bladders can be objectively quantified using the histological method described.

Distribution of neuropeptides, histamine content, and inflammatory cells in the ureter

OBJECTIVES

To determine the anatomic distribution of select neuropeptides (neurokinin A [NKA], substance P [SP], and bradykinin [BK]), of inflammatory cells (leukocytes and mast cells), and the histamine content in the normal swine ureter and compare the findings with regions of increased ureteral contractility.

METHODS

Ureters from 10 pigs were obtained and cut into eight segments, proximally to distally. A portion of each ureteral segment was suspended in Krebs buffer (37 degrees C) and attached to force displacement transducers, and spontaneous contractility was measured for 30 minutes. A second portion was assayed for histamine, NKA, SP, and BK using enzyme-linked immunosorbent assay. A third portion was fixed in 10% buffered formalin, stained with hematoxylin-eosin, and evaluated histologically.

RESULTS

Ureteral contractility was found to be highest in the most proximal and most distal regions of the ureter. Similarly, SP content was three times greater in the proximal ureter and two times greater in the distal ureter than in the midureter (P <0.05, n = 10). The total NKA and BK content were also higher in the proximal and distal ureter than in the midureter. Conversely, the histamine content was consistent throughout the ureter. Moreover, no significant difference in the distribution of inflammatory cells was identified throughout the ureter.

CONCLUSIONS

The anatomic distribution of NKA, SP, and BK in the ureter corresponded to regions of increased spontaneous ureteral contractility, more specifically the proximal and distal ureter. Neuropeptides may play a significant role in ureteral contractility and may be a target for pharmacologic mediation during obstruction and stone passage.

Substance P dependence of endosomal fusion during bladder inflammation

Urinary bladder instillation of ovalbumin into presensitized guinea pigs stimulates rapid development of local bladder inflammation. Substance P is an important mediator of this inflammatory response, as substance P antagonists largely reverse the process. Vacuolization of the subapical endosomal compartment of the transitional epithelial cells lining the bladder suggests that changes in endosomal trafficking and fusion are also part of the inflammatory response. To test directly for substance P mediation of changes in endosomal fusion, we reconstituted fusion of transitional cell endosomes in vitro using both cuvette-based and flow cytometry energy transfer assays. Bladders were loaded with fluorescent dyes by a hypotonic withdrawal protocol before endosomal isolation by gradient centrifugation. Endosomal fusion assayed by energy transfer during in vitro reconstitution was both cytosol and ATP dependent. Fusion was confirmed by the increase in vesicle size on electron micrographs of fused endosomal preparations compared with controls. In inflamed bladders, dye uptake was inhibited 20% and endosomal fusion was inhibited 50%. These changes are partly mediated by the neurokinin-1 (NK1) receptor (NK1R), as 4 mg/kg of CP-96,345, a highly selective NK1 antagonist, increased fusion in inflamed bladders but had no effect on control bladders. The receptor-mediated nature of this effect was demonstrated by the expression of substance P receptor mRNA in rat bladder lumen scrapings and by the detection of the NK1R message in guinea pig subapical endosomes by Western blot analysis. The NK1Rs were significantly upregulated following induction of an inflammatory response in the bladder. These results demonstrate that 1) in ovalbumin-induced inflammation in the guinea pig bladder, in vitro fusion of apical endosomes is inhibited, showing endocytotic processes are altered in inflammation; 2) pretreatment in vivo with an NK1R antagonist blocks this inhibition of in vitro fusion, demonstrating a role for NK1R in this process; and 3) the NK1R is present in higher amounts in apical endosomes of inflamed bladder, suggesting changes in translation or trafficking of the NK1R during the inflammatory process. This suggests that NK1R can change the fusion properties of membranes in which it resides.

Neurokinin-1 (NK-1) receptor is required in antigen-induced cystitis

Interstitial cystitis (IC) is a debilitating disease that has been adversely affecting the quality of women's lives for many years. The trigger in IC is not entirely known, and a role for the sensory nerves in its pathogenesis has been suggested. In addition to inflammation, increased mast cell numbers in the detrusor muscle have been reported in a subset of IC patients. Experimentally, several lines of evidence support a central role for substance P and neurokinin-1 (NK-1) receptors in cystitis. The availability of mice genetically deficient in neurokinin-1 receptor (NK-1R(-/-)) allows us to directly evaluate the importance of substance P in cystitis. An unexpected finding of this investigation is that NK-1R(-/-) mice present increased numbers of mast cells in the bladder when compared with wild-type control mice. Despite the increase in mast cell numbers, no concomitant inflammation was observed. In addition, bladder instillation of wild-type mice with a sensitizing antigen induces activation of mast cells and an acute inflammatory response characterized by plasma extravasation, edema, and migration of neutrophils. Antigen-sensitized NK-1R(-/-) mice also exhibit bladder mast cell degranulation in response to antigen challenge. However, NK-1R(-/-) mice are protected from inflammation, failing to present bladder inflammatory cell infiltrate or edema in response to antigen challenge. This work presents the first evidence of participation of NK-1 receptors in cystitis and a mandatory participation of these receptors on the chain of events linking mast cell degranulation and inflammation.

Nuclear factor kappa B mediates lipopolysaccharide-induced inflammation in the urinary bladder

PURPOSE

The proteins which constitute the final common pathway linking receptors on cell surfaces to the inflammatory cascade have recently been identified and cloned. Central to activation of this inflammatory cascade is translocation from cytosol to nucleus of the nuclear transcription factor known as nuclear factor-kappa B (NF-kappaB). The purpose of this study was to determine whether NF-kappaB cascade plays a role in lipopolysaccharide (LPS)-induced inflammation of the mouse urinary bladder.

MATERIALS AND METHODS

Bladder inflammation was induced in anesthetized mice by intravesical instillation of lipopolysaccharide (LPS) and quantified by morphometric analysis. The NK-1 receptors for substance P were quantified by flow cytometry. LPS-induced degradation of inhibitory IkappaB subunit was quantified by Western blotting analysis and translocation of NF-kappaB protein from cytosol to the nucleus was determined by confocal microscopy and Western blotting analysis. In addition, we determine the effect of lactacystin, a proteosome inhibitor, on LPS-induced IkappaB degradation and NF-kappaB translocation, NK-1 receptor fluorescence intensity, and bladder inflammation.

RESULTS

LPS instillation into the mouse bladder resulted in time dependent loss of the inhibitory IkappaB subunit of the NF-kappaB protein complex. IkappaB cleavage was followed by translocation of NF-kappaB from the cytosol to the nucleus. This was associated with increased expression of an NF-kappaB dependent inflammatory component, the NK-1 receptor. Pretreatment of mouse bladders with the NF-kappaB inhibitor, lactacystin, prevented cleavage of IkappaB in a dose-dependent manner. Lactacystin prevented increases in the NF-kappaB dependent inflammatory cascade components such as the NK-1 receptor. At the whole tissue level, the marked inflammatory infiltrate and mucosal breakdown associated with LPS administration was completely abolished by lactacystin.

CONCLUSION

NF-kappaB mediates many features of urinary bladder inflammation induced by LPS. The NF-kappaB cascade is an important target for anti-inflammatory management of cystitis.

Selective cyclooxygenase-2 inhibitors reduce ureteral contraction in vitro: a better alternative for renal colic?

PURPOSE

To quantitate the effects of a selective cyclooxygenase (COX)-2 inhibitor, NS-398, on porcine and human ureteral contractility in vitro.

MATERIALS AND METHODS

This study was performed in 3 distinct groups. In group 1, segments of ureter were obtained from freshly sacrificed domestic swine. Sections were isolated and suspended longitudinally. Twenty-four ureteral segments were treated with either indomethacin (a nonselective COX inhibitor), NS-398 (selective COX-2 inhibitor), or DMSO (control). Spontaneous contractions were then recorded in each group. In group 2, fifteen segments of human ureter were obtained from patients undergoing donor nephrectomy or ureteral reimplantation. Segments were isolated and suspended as above, and treated with either indomethacin, NS-398, or DMSO. In group 3, eighteen sections of human ureter obtained from donor nephrectomy patients were passively sensitized for 20 hours in ragweed allergic donor serum. Ureteral segments were then treated with either indomethacin, NS-398 or DMSO, and then the segments were subsequently exposed to ragweed antigen and contractions were subsequently recorded.

RESULTS

In group 1, the average time to 100% inhibition of spontaneous contraction was 48.8 minutes (S.E.M. = 7.9) for indomethacin, 65.7 minutes (S.E.M. 6.7) for NS-398, and beyond 150 minutes for DMSO. The percent reduction was 100% for indomethacin (S.E.M. = 0), 92.5% for NS-398 (S.E.M. 4.9%), and 52.9% for DMSO (s.e.m. = 10.8%). In group 2, the average time to 100% inhibition was 29 minutes (S.E.M. = 10.4) for indomethacin, 21 minutes (S.E.M. 4.8) for NS-398, and beyond 150 minutes for DMSO. The percent reduction was 100% for indomethacin (S.E.M. = 0), 100% (S.E.M. = 0) for NS-398, and 20% (S.E.M. = 12%) for DMSO. In group 3, ragweed sensitized ureters treated with DMSO (control group) contracted an average maximum of 10 times per 5 minutes. Antigen failed to induce contractions of sensitized tissues treated with indomethacin or NS-398.

CONCLUSION

A selective COX-2 inhibitor (NS-398) reduces ureteral contractility as effectively as indomethacin (a nonselective COX inhibitor) in both porcine and human ureteral segments in vitro (p <0.05). Selective COX-2 inhibitors may have significant clinical potential in treating renal colic as they cause less gastric ulceration.

Nerve-mediated motility of ileal segments isolated from NK(1) receptor knockout mice

Tachykinins such as substance P (SP) and neurokinin A (NKA) acting on neurokinin (NK) receptors modulate the nonadrenergic noncholinergic (NANC) neurotransmission in the gastrointestinal tract of several species, but the information about the mouse small intestine is scanty. Both SP and NKA induced concentration-dependent contractions of ileal segments isolated from wild-type mice that were blocked by NK(1) and NK(2) antagonists, respectively. In contrast, segments isolated from NK(1) receptor (NK(1)-R) knockout mice responded only to elevated concentrations of SP. To reveal the inhibitory NANC (iNANC) responses, tissues were pretreated with atropine and guanethidine. Under these conditions, a tetrodotoxin-sensitive relaxation in response to electrical field stimulation (EFS) was observed. NK(1)-R knockout mice presented a trend toward an increase in iNANC responses, whereas the NK(1)-R antagonist significantly potentiated iNANC relaxation in tissues isolated from wild-type mice. N(G)-nitro-L-arginine methyl ester (100 microM) transformed the relaxant response to EFS into a tetrodotoxin-sensitive, frequency-dependent contraction characteristic of an excitatory NANC (eNANC) system. A NK(1)-R antagonist abolished the contractile responses of the mouse ileum to EFS, whereas a NK(2) receptor antagonist had a trend toward reducing EFS-induced contraction. The eNANC component was absent in NK(1)-R knockout mice. Measurement of SP-like immunoreactivity indicated similar amounts of SP per gram of tissue isolated from wild-type and NK(1)-R knockout mice, indicating that the observed differences in response to EFS were not due to a differential peptide content. It is concluded that, in the mouse ileum, both NK(1) and NK(2) receptors modulated the responses to exogenous tachykinins, whereas NK(1) is the primary tachykinin receptor involved in both iNANC and eNANC transmission.

Mast cells mediate the severity of experimental cystitis in mice

PURPOSE

We hypothesized that experimental cystitis induced by substance P (SP) or E. coli lipopolysaccharide (LPS) would be less severe in mice rendered mast cell deficient by genetic manipulation.

MATERIALS AND METHODS

Two strains of mast-cell deficient mice (WBB6F1- kitW/kitW-v or kitW/kitW-v and WCB6F1-Sl/Sld or Sl/Sld) and their congenic, normal (+/+) counterparts were used. Cystitis was induced in female mice by intravenous injection of SP (0.1 ml.; 10(-6) M) or E. coli LPS (0.1 ml.; 2 mg./ml.), and inflammation was assessed by Evans blue dye extravasation. In a separate group of kitW/kitW-v and congenic normal mice, cystitis was induced by intravesical infusion of SP (0.05 ml.; 10(-5) M) or E. coli LPS (0.05 ml.; 100 microg./ml.) and compared with intravesical pyrogen-free saline (0.05 ml.; 0.9%). Severity of cystitis was determined by histological evaluation of the bladder wall 24 hours after intravesical infusions.

RESULTS

Intravenous SP or LPS stimulated increased plasma extravasation in congenic normal mice but not in mast cell-deficient mice. Intravesical SP or LPS resulted in increased edema, leukocytic infiltration, and hemorrhage within the bladder wall in congenic normal mice, but the only histological evidence of inflammation in the bladders of kitW/kitW-v mice was increased hemorrhage in response to LPS.

CONCLUSIONS

This study indicates that mast cells modulate the inflammatory response of the bladder to SP and LPS in mice. Although clinical trials of the use of antihistamines to treat or prevent cystitis have not been successful, these results suggest that therapies directed toward preventing mast cell activation may yet prove effective in treating cystitis.

[The beginnings of physiology of the human brain, from antiquity to the Renaissance]

For more than 3,000 years in Western civilizations, the knowledge of the human body gained very little ground at first, due to taboos. The body was regarded as sacred and Medicine only resorted to plants in order to heal. Hippocrates was not familiar with anatomy as the human body could not be dissected. He developed a theory of humors connected with the primary elements and opposing the dry and the moist. Even though he did not know the nervous system, he nonetheless pointed out that emotions stemmed from the brain and were caused ty particles (pneuma) emitted by the objects around us. Galien was one of the first to mention physiology but could only dissect animals to understand Man. He took up the theory of humors but did not reach any concrete results as he considered the brain as made up of faeces. Only in 1000 AD did Avicenne try to shape the cell theory with its three cells (the ventricles in today's parlance) in direct relation to the nerves, which he described but did not represent. Representation of the nerves was only be given in the mid-13th century by Khalifah in his ophtalmology treaty. Finally, during the Renaissance, when books started conveying both text and pictures, brain physiology emerged; Albert le Grand was its first expounder and his work was then taken up in a 1475 inculabulum in which 5 cells instead of 3 are described and represented. Leonardo da Vinci was the second one; at the end of the 15th century he dissected may corpses to understand human morphology. Unfortunately his work, which was conducted very rigorously from an anatomical point of view only surfaced at the end of the 19th century. He was the first to conduct the anatomical cross-dissection of the brain. Last came Magnus Hundt and Georg Reisch; in the early 16th century they still represented the three cells of Avicenne even though Reisch described more sophisticated connections between the organs of the senses.

Elevated tryptase, nerve growth factor, neurotrophin-3 and glial cell line-derived neurotrophic factor levels in the urine of interstitial cystitis and bladder cancer patients

PURPOSE

The 2 prominent features of interstitial cystitis are pain and increased numbers of mast cells in the bladder. In this pilot study we determined the concentration of soluble mediators associated with activation of sensory neurons and/or mast cells that were present in the urine.

MATERIALS AND METHODS

The study groups included 4 interstitial cystitis patients, 7 kidney donors with no history of bladder disease as negative controls, 6 bladder cancer patients and 7 patients with urinary tract infection as reference controls. Urine samples were assayed for different soluble mediators using immunoassays for tryptase (a marker for mast cell activation), neurotrophic factors (markers of neuronal plasticity) and chemokines (markers of inflammatory cell activity). Results were normalized based on creatinine concentration.

RESULTS

There was a marked increase in the average amounts of tryptase and 3 neurotrophic factors in patient urine. Interestingly, the mediator profile in the urine of bladder cancer patients was indistinguishable from that of interstitial cystitis patients with respect to these same 4 proteins. There was no difference between normal control and urinary tract infection urine samples.

CONCLUSIONS

These findings may account for several clinical and pathological features found in interstitial cystitis and bladder cancer. Although preliminary due to the limited numbers of patients, they also suggest that increased levels of neurotrophin-3, nerve growth factor, glial cell line-derived neurotrophic factor and tryptase in the urine could serve as a basis for adjunct diagnosis, monitoring and treatment of interstitial cystitis.

NK-2 is the predominant tachykinin receptor subtype in the swine ureter

OBJECTIVE

To determine which of the known tachykinin receptor subtypes is predominant in the swine ureter.

MATERIALS AND METHODS

Ureters from adult pigs were harvested, cut into longitudinal strips and placed in 10 mL tissue baths containing Krebs buffer, under 4 g of initial tension. The magnitude and frequency of contractions were recorded. Tissues were incubated with 1 micromol/L solutions of peptidase inhibitors (phosphoramidon and captopril) for 1 h to inhibit degradation of peptides and treated with either CP 96,345 (NK-1 receptor antagonist), SR 48,968 (NK-2 receptor antagonist) or saline (control). Concentration-response curves to the tachykinins substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) were determined.

RESULTS

Ureteric segments showed a concentration-dependent response to all tachykinins; NKA stimulated increased contractions at a lower concentration than either SP or NKB (P<0.05). This was reflected by the difference in the effective concentration required to obtain half the maximal response (EC50 ) for each of the peptides. The mean (sd) EC50 values were (micromol/L): NKA, 0.2 (0.02); SP, 3.5 (0.7); and NKB, 4.5 (1.7). In addition, the selective NK-2 antagonist (SR 48,968) significantly reduced contractile responses to all peptides, as indicated by a 10-fold rightward shift of the concentration-response curves (P<0. 05), whereas the NK-1 antagonist (CP 96,345) had no significant effect.

CONCLUSION

These results indicate that NK-2 is the predominant tachykinin receptor subtype responsible for contraction of ureteric smooth muscle. The use of mediators which act on NK-2 receptors may have clinical applications for the treatment of ureteric disease.

Evaluation of ureteric contraction: a comparison among ring, spiral-cut and longitudinal segments

OBJECTIVE

To determine the optimal contractile response of isolated ureters to inflammatory mediators and neurotransmitters by evaluating four common methods of ureteric suspension.

MATERIALS AND METHODS

Ureters from adult domestic swine were placed immediately in Krebs buffer and cut into 4-5 mm segments. Four methods of suspension were compared: (i) an unopened ring segment suspended horizontally; (ii) a spirally cut segment (lumen cut open at a 45 degrees and suspended end-to-end); (iii) an open longitudinal segment; and (iv) a closed longitudinal segment. All segments were placed in individual water-jacketed tissue baths containing Krebs buffer, the frequency of contraction measured using a force transducer and registered on a polygraph. The sensitivity of all four segments was tested by measuring the tension and frequency in response to increasing frequencies of electric field stimulation, and by a cumulative concentration-response curve to carbachol.

RESULTS

Ureteric segments responded with an increased frequency of contraction depending on the intensity of stimulus to both electric field stimulation and carbachol. However, there were no significant differences in spontaneous levels of contraction, sensitivity or maximal response among the methods of suspension in response to electric field stimulation or carbachol.

CONCLUSION

These results indicate that all four methods of suspending the ureteric segments produce contractile responses sensitive enough to study the action of various neurotransmitters.

MR imaging anatomy of the optic pathways

Imaging in neuro-ophthalmology is a major, developing field. Visual and motor ocular symptoms and signs are of diagnostic and localizing significance, and occur frequently in patients with brain space-occupying lesions. Knowledge of the anatomy of the optic pathways extending from the retina to the calcarine fissure throughout the brain is crucial. Multiplanar high resolution MR imaging permits the physician to depict the visual path with exquisite detail. This article provides a correlative regional anatomic and imaging atlas of the brain following the optic pathways, with reference to the most accurate technical imaging procedures.

Lipopolysaccharide upregulates bradykinin 1 receptors in the isolated mouse bladder

PURPOSE

Bradykinin 1 (B1) receptors have been shown to be upregulated at sites of inflammation. The purpose of this study was to determine the effect of lipopolysaccharide (LPS) on B1 receptor modulation in the isolated mouse bladder.

MATERIALS AND METHODS

The contractile responses of isolated mouse bladder to B1 and B2 agonists were determined in vitro following prolonged incubation with LPS or saline.

RESULTS

Bradykinin (BK), a B2 agonist, but not des-Arg9-bradykinin (DABK), a B1 agonist, was found to be a potent contractile agonist of the mouse urinary bladder under basal conditions. However, both sensitivity and maximal response to DABK increased during a second exposure to the agonist in a time-dependent manner. In vivo or in vitro treatment with LPS increased both sensitivity and maximal response of isolated bladders to DABK, whereas bladder contraction to BK and other peptides remained the same. Treatment of tissues with a B1 receptor antagonist 45 minutes prior to second exposure to DABK, or the prostaglandin synthesis inhibitor, indomethacin, 30 minutes prior to LPS or saline incubation, significantly inhibited the increase of both maximal response and sensitivity.

CONCLUSIONS

These results indicate that bladder B1 receptors can be upregulated by LPS, and that prostaglandins seem to mediate the effects of the B1 receptor activation in the isolated mouse bladder.

In vitro passive sensitization of the ureter as a basis for the study of noninfectious ureteral inflammation

PURPOSE

To develop an in vitro model of passive sensitization for the ureter for the study of noninfectious ureteral inflammation.

MATERIALS AND METHODS

Human ureteral tissues were obtained from excess segments of ureters from patients undergoing donor nephrectomy. Following excision, ureters were placed in physiologic salt solution (PSS) and passively sensitized by incubating with ragweed serum from allergic donor (1 ml. serum: 4 ml. PSS) for 20 hours at room temperature. Ureteral segments were incubated with PSS only and served as non-sensitized controls (n = 4). After sensitization, excess serum was removed by serial washing with PSS without serum. Ureteral strips were then suspended in vitro for determination of tissue contraction. Contractile responses and histamine release were measured. Tissues were then exposed to antigen. To investigate the role of inflammatory mediators in tissue contraction, 4 groups of 8 sensitized ureteral segments were incubated for 1 hour with the following substances: a H1 histamine receptor antagonist (pyrilamine), an inhibitor of prostaglandin synthesis (indomethacin), an inhibitor of leukotriene synthesis (A-64077), and a control substance (DMSO). Following incubation, the tissues were exposed to antigen, and contraction and histamine release were determined.

RESULTS

Sensitized ureteral segments (n = 8) responded to antigen with contraction (30% BaCl maximum; p <0.01) and histamine release (205/ng./gm. tissue) within the first 5 minutes of superfusion. Non-sensitized control segments (n = 4) did not respond. Both indomethacin and pyrilamine reduced (7-10% of BaCl maximum; p <0.05) the contractile response of sensitized ureter to antigen, whereas A-64077 did not. Analysis of the superfusate for histamine indicates that indomethacin reduced histamine release (150 ng./gm.) whereas A-64077 and pyrilamine did not (p <0.05).

CONCLUSION

We have demonstrated that ureteral segments can be passively sensitized and that subsequent antigen challenge stimulates contraction and histamine release. Our findings suggest that contraction of ureteral tissue and histamine release may be utilized as an inherent bioassay indicating the activity of inflammatory mediators. In addition, these results suggest that both prostaglandins and histamine, but apparently not leukotrienes, participate in the early inflammatory response to antigen challenge of the sensitized ureter.

Anti-immunoglobulin E antibody treatment blocks histamine release and tissue contraction in sensitized mice

Inhibition of antigen-specific IgE response has been shown to lead to amelioration of allergic disease symptoms. In an effort to design a therapy aimed at decreasing IgE levels, we reported previously that treatment of mice with an anti-IgE antibody coincident with the primary antigen immunization resulted in significant decreases in antigen-specific IgE synthesis, without substantially altering IgG levels. In the present study, we employed this mouse model and a surrogate antibody to investigate the capacity of anti-IgE treatment to block an established IgE response in vivo. Results of these experiments suggest that anti-IgE treatment concomitant with an antigen boost results in removal of detectable circulating IgE for at least 7 weeks (the duration of the study). Moreover, tissues removed from mice following anti-IgE treatment failed to release histamine and contract in response to antigen challenge ex vivo. These findings demonstrate that reduction of circulating IgE correlates to an inhibition of tissue mast cell sensitization and mediator release in response to antigen challenge and further supports the concept of anti-IgE treatment as a promising therapy for the treatment of allergic disease.

Dog model for studying detrusor instability secondary to acutely induced variable bladder outlet obstruction

BACKGROUND

Involuntary detrusor contractions often cause irritative symptoms such as urgency and incontinence. A dog model for acutely induced variable bladder outlet resistance was developed to investigate the possible role of prostatic afferent nerve fibers in the development and maintenance of detrusor instability.

METHODS

Fifty-eight mongrel dogs (weight range 19.5-36.5 kg) were divided into five groups: group I (n = 11) had surgically induced bladder outlet obstruction. Group II (n = 14) had urinary obstruction and bilateral sectioning of the lowest branches of the pelvic plexus supplying the prostate. Group III (n = 10) had prostate denervation only. Groups IV (n = 10) and V (n = 13) were sham-operated and controls, respectively. In the obstructed groups (I and II), an artificial urinary sphincter (length 4.5-6.0 cm) was placed around the bladder neck and connected to a reservoir placed subcutaneously to allow postoperative adjustments of urinary resistance. All dogs were evaluated at baseline and postoperatively at 1, 3, and 6 months with uroflowmetry, postvoid residual urine volume, cystometry as well as serum creatinine, and urinalysis.

RESULTS

Occurrences of detrusor instability were not associated with prostatic denervation input. The mean peak flow rates decreased significantly in the obstructed groups at all follow-ups, but did not change significantly in the nonobstructed groups. Postoperatively, the mean maximum bladder capacity was significantly decreased for groups I and II only. However, a significant correlation between maximum bladder capacity and maximum detrusor pressure could not be detected at any time point in any of the groups. Mean postvoid residual urine volume varied considerably in all groups over time. Creation of a urinary model of infravesical obstruction was associated with considerable problems.

CONCLUSIONS

In our dog model of bladder outlet obstruction, prostatic sensory nerve fibers appear not to be involved in detrusor instability. Surgical induction of a constant model of bladder outlet obstruction was difficult even in a large animal. The observations from the present study raise questions about the validity of obstructive urinary animal models.

Effects of Pasteurella haemolytica leukotoxin and lipopolysaccharide on histamine, prostanoid, and leukotriene release by bovine lung parenchyma in vitro

OBJECTIVE

To identify the effect of Pasteurella haemolytica lipopolysaccharide (LPS) and leukotoxin (LKT) on spontaneous and calcium ionophore-induced histamine and inflammatory mediator release from isolated bovine lung parenchyma.

SAMPLE POPULATION

Lungs from 8 healthy cattle.

PROCEDURE

Isolated bovine lung parenchyma was incubated in vitro for 2 hours with LKT or LPS, and spontaneous and induced release of inflammatory mediators was determined.

RESULTS

LKT and LPS increased spontaneous release of histamine and leukotriene B4. In addition, incubation with LPS increased spontaneous release of prostaglandin E2. Moreover, a differential effect of the 2 toxins on calcium ionophore-induced inflammatory mediator release was observed. LKT specifically primed isolated lung parenchyma to release leukotriene B4 and thromboxane B2 in response to calcium ionophore, whereas LPS did not alter the profile of prostanoids released by bovine lung tissue exposed to calcium ionophore.

CONCLUSIONS

Pasteurella haemolytica toxins have a direct effect on bovine lung parenchyma, causing release of inflammatory mediators, which contribute to response to infection. Furthermore, bacterial toxins (LKT in this study) may sensitize tissues to the effects of other irritant stimuli, amplifying the inflammatory response.

Kinetics of peptide-induced release of inflammatory mediators by the urinary bladder

OBJECTIVE

To investigate the release of inflammatory mediators by the urinary bladder in response to exposure to pro-inflammatory peptides.

MATERIALS AND METHODS

Isolated guinea pig urinary bladder was incubated with 10 mumol/L each of substance P (SP), neurokinin A (NKA), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP), octreotide acetate (a long-acting analogue of somatostatin, SOM), or bradykinin (BK), and the release of histamine, prostaglandin (PG) E2, PGF2 alpha and leukotriene B4 (LTB4) was determined during 0-5, 5-30 and 30-120 min after addition.

RESULTS

Substance P, NKA, VIP and BK stimulated the release of histamine, while CGRP and SOM suppressed the release to below the spontaneous rates. All peptides, except CGRP and SOM, stimulated the release of PGE2 between 0 and 30 min, and only VIP failed to stimulate the release of PGF2 alpha within 5 min of exposure. Substance P, NKA, VIP and BK stimulated the release of LTB4 and this required > 5 min of exposure.

CONCLUSION

These results indicate that the peptides evaluated induce an immediate and transient release of histamine and activation of cyclooxygenase and delayed activation of 5-lipoxygenase. These actions may directly regulate the participation of these peptides in the pathogenesis of cystitis.

Neurogenic vasoreactive response of human internal thoracic artery smooth muscle

The interaction between primary afferent neurons containing neuropeptides and the vascular smooth muscle is incompletely understood. To explore the function of perivascular afferent neurons and to determine whether they produce local effects on vascular smooth muscle cells, we investigated the effects of acute capsaicin and substance P administration in vitro on human internal thoracic arteries (ITA). Vessels were obtained from patients undergoing coronary bypass or from multiorgan transplant donors. Fourteen ITA segments (5 mm wide) were suspended as rings between two stainless-steel stirrups in water-jacketed (37 degrees C) tissue baths under 2.5 to 3 g of basal tension. The tissue baths contained 10 mL physiological salt solution (PSS) of the following composition (mM): NaCl, 119; KCl, 4.7; NaH2PO4, 1.0; MgCl2, 0.5; CaCl2, 2.5; NaHCO3, 25; and glucose, 11; aerated continuously with 95% O2 and 5% CO2. Peptidase inhibitors (phosphoramidon and captopril) were added to PSS to decrease peptide degradation. Mechanical responses were measured isometrically and recorded on a polygraph via isotonic force transducers. Vessels were preconstricted with submaximal concentrations of norepinephrine. After the tension had stabilized, substance P or capsaicin was added cumulatively to the tissue bath. At the end of the experiments, the viability of ITA was verified by its responses to endothelial-dependent (acetylcholine) and endothelial-independent (sodium nitroprusside) vasodilators. In the endothelium-intact ITA segments, substance P produced relaxation of ITA smooth muscle while it induced slight contraction when the ITA was devoid of its endothelium (P = 0.0585). The addition of capsaicin to human ITA primarily produced contractile effects on the developed smooth muscle force. The capsaicin-induced contraction of the ITA smooth muscle was independent of endothelial cell integrity, although contraction was greater in the endothelium-intact ITA segments (P = 0.0165). The acute capsaicin exposure of human ITA revealed that primary afferent neurons containing neuropeptides innervate human ITAs. There is a real potential for perivascular afferent neurons and sensory peptides to influence the ITA smooth muscle function.

Effect of octreotide, a somatostatin analogue, on release of inflammatory mediators from isolated guinea pig bladder

OBJECTIVE

Somatostatin has been demonstrated to inhibit inflammation under certain circumstances. We hypothesized that in vivo treatment with octreotide, a long-acting analogue of somatostatin analogue, would diminish the capacity of inflammatory peptides to stimulate in vitro release of inflammatory mediators by the bladder.

METHODS

Female guinea pigs were injected with octreotide (20 mg./kg. i.m.) prior to euthanasia. Control guinea pigs received no treatment prior to euthanasia. Urinary bladders were removed and incubated with substance P (SP, 10 microM), neurokinin A (NKA, 10 microM), or bradykinin (BK, 10 microM) in the presence or absence of indomethacin (50 microM), and release of histamine, prostaglandins (PGE2 and PGF2 alpha), and leukotriene (LTB4) was determined.

RESULTS

Sensory peptides and BK induced time-dependent release of histamine and eicosanoids from isolated urinary bladder. Blockade of cyclooxygenase with indomethacin (50 microM) abolished peptide-induced prostaglandin release but enhanced LTB4 release. In vivo octreotide pretreatment decreased peptide-induced histamine release, had no effect on PGE2 or PGF2 alpha release, and LTB4 release. However, octreotide prevented the increase in LTB4 release in tissues incubated with indomethacin.

CONCLUSIONS

These results indicate that somatostatin has the capacity to suppress the release of histamine and prevents potentiation of LTB4 release by indomethacin by the guinea pig bladder in response to pro-inflammatory peptides, indicating that somatostatin may be useful in preventing or treating some forms of cystitis.

Involvement of leukotrienes, TNF-alpha, and the LFA-1/ICAM-1 interaction in substance P-induced granulocyte infiltration

Substance P (SP) has been shown to mediate granulocyte infiltration into the mouse skin by inducing mast cell degranulation. In this study, using a variety of specific inhibitors, we investigated the cascade of events involved in the response of neutrophils and eosinophils to SP. The prostaglandin inhibitor, indomethacin, had little effect on SP-induced leukocyte migration. In contrast, pretreatment with the leukotriene (LT) synthesis inhibitor, A-64077, completely blocked neutrophil but not eosinophil migration in response to SP. Participation of tumor necrosis factor alpha (TNF-alpha) and LFA-1/ICAM-1 interaction was confirmed by inhibition of SP-induced leukocyte migration by pretreatment of mice with monoclonal antibodies to TNF-alpha, LFA-1, and ICAM-1. Moreover, alteration in leukocyte migration by indomethacin was found to depend on the concentration of TNF-alpha used. Indomethacin did not alter the number of leukocytes induced by low concentrations of TNF-alpha (0.1 ng), but reduced the number of cells stimulated with high TNF-alpha concentrations (1.0 ng). These results support the concept that SP modulates in vivo neuroinflammatory responses, as measured by granulocyte migration, initiating a cascade of events that includes LT production, TNF-alpha secretion, and engagement of LFA-1 and ICAM-1.

Spontaneously released substance P and bradykinin from isolated guinea-pig bladder

OBJECTIVES

To investigate whether the isolated urinary bladder spontaneously releases substance P (SP) or bradykinin (BK), which can act as potent mediators of pain and inflammation of the urinary bladder, and whether peptidase inhibitors enhance peptide release.

MATERIALS AND METHODS

Urinary bladder segments (2 x 10 x 0.8-1 mm) were isolated from guinea pigs and studied in vitro; tissue contraction was assessed using force-displacement transducers and the release of peptides by specific enzyme immunoassays.

RESULTS

In the absence of any exogenous agonists, the inhibition of neutral endopeptidase and angiotensin-converting enzyme by phosphoramidon and captopril, respectively, increased the frequency and magnitude of spontaneous motility of isolated bladder strips. Phosphoramidon increased the net release of SP-like immunoreactivity (SP-LI) and captopril increased the net release of SP-LI and BK-LI, concomitant with contraction. Peptide-LI was recovered primarily from bladder mucosa and to a lesser degree from detrusor smooth muscle. Similarly, peptidase inhibitors primarily affected the bladder mucosa; phosphoramidon induced a fourfold increase in SP-LI and captopril induced a significant increase of SP-LI and BK-LI from the mucosa. Tissues contracted in response to peptidase inhibitors in the presence of atropine and indomethacin, but contraction was reduced significantly by in vitro capsaicin desensitization or removal of bladder mucosa. BK stimulated SP-LI release from mucosa but not detrusor. SP stimulated increased BK-LI release from mucosa and detrusor.

CONCLUSIONS

These findings indicate the basal release of peptide-like immunoreactivity by isolated bladder and further support the concept that peptidases located in the bladder mucosa are important in terminating the effects of endogenous peptides.

Use of gold-labeled ovalbumin to correlate antigen deposition and localization with tissue response

This study was performed to evaluate a technique for correlating the location of antigen within sensitized tissues with physiological response. Guinea pigs actively sensitized by intraperitoneal injection of ovalbumin (OVA) were euthanized, and urinary bladders were removed. Gold beads (18 nM diameter) were conjugated to OVA (OVA-Au) and bovine serum albumin (BSA-Au). Bladder tissue was suspended in tissue baths, exposed to OVA, OVA-Au, BSA, and BSA-AU, and tissue contraction and histamine release were determined. Bladder tissues were examined by electron microscopy to determine distribution of gold-labeled antigen at 1 and 5 min after exposure. Exposure of bladder tissue from sensitized guinea pigs to OVA stimulated concomitant contraction and histamine release which reached maximal levels within 3 min; bladder tissue from control, nonsensitized guinea pigs did not respond to OVA. BSA failed to stimulate response from OVA-sensitized or control bladder tissue. Labeled antigen was adhered to mucosa of sensitized bladder tissue 1 min after exposure to OVA-Au. OVA-Au was present within the mucosa and submucosa of sensitized tissues within 5 min. OVA-Au did not adhere to, or become internalized by, control tissues, and BSA-Au did not adhere to, or become internalized by, any tissues. Labeling of antigen with gold allowed the location of antigen within tissues to be determined and did not affect the response of sensitized tissues to antigen exposure.