Anti-inflammatory effects of infliximab in mice are independent of tumour necrosis factor α neutralization.

Infliximab (IFX) has been used repeatedly in mouse preclinical models with associated claims that anti-inflammatory effects are due to inhibition of mouse tumour necrosis factor (TNF)-α. However, the mechanism of action in mice remains unclear. In this study, the binding specificity of IFX for mouse TNF-α was investigated ex vivo using enzyme-linked immunosorbent assay (ELISA), flow cytometry and Western blot. Infliximab (IFX) did not bind directly to soluble or membrane-bound mouse TNF-α nor did it have any effect on TNF-α-induced nuclear factor kappa B (NF-κB) stimulation in mouse fibroblasts. The efficacy of IFX treatment was then investigated in vivo using a TNF-α-independent Trichuris muris-induced infection model of chronic colitis. Infection provoked severe transmural colonic inflammation by day 35 post-infection. Colonic pathology, macrophage phenotype and cell death were determined. As predicted from the in-vitro data, in-vivo treatment of T. muris-infected mice with IFX had no effect on clinical outcome, nor did it affect macrophage cell phenotype or number. IFX enhanced apoptosis of colonic immune cells significantly, likely to be driven by a direct effect of the humanized antibody itself. We have demonstrated that although IFX does not bind directly to TNF-α, observed anti-inflammatory effects in other mouse models may be through host cell apoptosis. We suggest that more careful consideration of xenogeneic responses should be made when utilizing IFX in preclinical models.

Zinc depletion regulates the processing and secretion of IL-1ß.

Sterile inflammation contributes to many common and serious human diseases. The pro-inflammatory cytokine interleukin-1ß (IL-1ß) drives sterile inflammatory responses and is thus a very attractive therapeutic target. Activation of IL-1ß in sterile diseases commonly requires an intracellular multi-protein complex called the NLRP3 (NACHT, LRR, and PYD domains-containing protein 3) inflammasome. A number of disease-associated danger molecules are known to activate the NLRP3 inflammasome. We show here that depletion of zinc from macrophages, a paradigm for zinc deficiency, also activates the NLRP3 inflammasome and induces IL-1ß secretion. Our data suggest that zinc depletion damages the integrity of lysosomes and that this event is important for NLRP3 activation. These data provide new mechanistic insight to how zinc deficiency contributes to inflammation and further unravel the mechanisms of NLRP3 inflammasome activation.

Failure of naltrexone hydrochloride to reduce self-injurious and autistic behavior in mentally retarded adults. Double-blind placebo-controlled studies.

BACKGROUND: It is hypothesized that self-injurious behavior (SIB) and symptoms of autism may be due to overactivity in some opioid systems in the brain. We examined the efficacy and safety of naltrexone hydrochloride, an opioid antagonist, in the treatment of SIB and autism in mentally retarded adults. METHOD: Thirty-three mentally retarded adults with autism and/or SIB participated in double-blind, placebo-controlled crossover studies. Active treatment was first a single 100-mg dose of naltrexone hydrochloride. Subsequently, 19 subjects were treated with 50 mg/d and 14 with 150 mg/d of naltrexone hydrochloride for 4 weeks. The outcome was assessed by means of direct observations (n = 11) and on the basis of scores on a list of target behaviors, the Aberrant Behavior Checklist, and the Clinical Global Impression Scale. RESULTS: Thirty-two subjects (seven with autism, 16 with autism and SIB, and nine with SIB) completed the trial. Naltrexone treatment failed to have therapeutic effects on SIB and autism. On the contrary, naltrexone increased the incidence of stereotypic behavior on the Aberrant Behavior Checklist, and the care staff evaluated the effect of the 50-mg/d treatment as being significantly worse than that of the placebo treatment as measured by the Clinical Global Impression Scale. CONCLUSION: Our findings suggest that naltrexone has no clinical value for a broad group of mentally retarded subjects with SIB and/or autism.

Defective sterol C5-6 desaturation and azole resistance: a new hypothesis for the mode of action of azole antifungals.

Two azole resistant isolates of Saccharomyces cerevisiae carried mutations allelic to erg 3 and were blocked to differing degrees at the C5-6 desaturation step of ergosterol biosynthesis. When treated with the sterol 14 alpha-demethylation inhibitor fluconazole the wild-type sensitive strain accumulated lanosterol and 14 alpha-methyl-erogosta-8,24(28)-dien-3 beta, 6 alpha-diol (14-methyl-3,6 diol). The stringent desaturase mutant, A2, accumulated 14 alpha-methyl-8,24(28)-dien-3 beta-ol (14-methyl fecosterol) and lanosterol as the major sterol components when treated with fluconazole. Resistant isolate A3 accumulated 14-methyl-3,6-diol, 14-methyl fecosterol, and lanosterol and was only partially blocked at sterol C5-6 desaturation. We conclude that functional sterol C5-6 desaturase is required for the synthesis of 14-methyl-3,6-diol under conditions of azole inhibition. We present a new hypothesis for the mode of action of azole antifungals based on the inability of 14-methyl-3,6-diol to support growth, and suggest that growth can occur through utilisation of 14-methyl fecosterol, produced by a combination of azole inhibition and defective sterol C5-6 desaturation.

Transitional cell carcinoma of the renal pelvis and ureter.

In a retrospective study of 185 patients with transitional cell carcinoma of the renal pelvis and ureter, of whom 127 were treated by total nephroureterectomy and 58 by conservative resection, the survival of those with superficial well differentiated tumours was greater than 90% in each group. When urothelium was left behind after conservative resection, there was a 22% rate of recurrence on the same side but this almost only occurred when the original tumour had been multifocal. Post-operative radiotherapy did not improve survival.

Chemotherapy for carcinoma in situ of the bladder.

In an 8-year period, 71 patients were diagnosed as having carcinoma in situ of the bladder. Twenty patients with primary carcinoma in situ were treated with systemic cyclophosphamide or intravesical mitomycin C and 19 of them survived 3 years. Three patients required cystectomy: 1 for invasive cancer and 2 for intractable symptoms in the absence of tumour. Fifty-one patients had either secondary or concomitant carcinoma in situ. Systemic or intravesical chemotherapy was given to 28 patients in whom carcinoma in situ was associated with G1 or G2 exophytic superficial tumour: there was only one cancer death in 3 years. Fifteen patients with G3 carcinoma in situ associated with a G3 or invasive exophytic tumour were treated with radiotherapy: 9 responded but 4 of the 6 with radio-insensitive tumours died of cancer within 3 years. Eight patients with secondary carcinoma in situ were managed by transurethral resection alone: in 6 there was spontaneous regression and 2 developed muscle invasion within 1 year. These results compare well with those of immunotherapy or early radical surgery and suggest that chemotherapy should be given a trial in patients with carcinoma in situ.

T3 bladder cancer: salvage rather than elective cystectomy after radiotherapy.

Treatment of a series of 194 patients with T3 (B2/C) tumors by radical radiotherapy, 5,000 to 5,500 rad in four weeks, produced a five-year survival of 40 per cent. Patients whose tumor completely disappeared after treatment (N = 97) had a five-year survival of 69 per cent. These results raise doubts about the necessity of performing elective cystectomy in patients who achieve complete response after radiotherapy, though the significantly better survival of partial responders who underwent salvage cystectomy emphasizes the need for an active policy of cystectomy once failure to respond completely to radiotherapy has been established and a need for techniques to give early indication of nonresponse to radiotherapy.

Squamous cell carcinoma of bladder.

Examination of the histology of all bladder tumors presented to the London Hospital over a ten-year period revealed a surprisingly low incidence of squamous bladder carcinoma. We would support the view of other workers that this tumor usually presents at an advanced stage and carries with it a poor prognosis. However, when no evidence of metastatic disease is evident, treatment with standard protocol of radiation therapy and cystectomy should achieve the same results as for the transitional cell tumor. Squamous cell carcinoma of the bladder would appear to be as radiosensitive as its transitional cell counterpart.

Methotrexate in the treatment of metastatic and recurrent primary transitional cell carcinoma.

Results in a series of 60 patients with recurrent or metastatic transitional cell carcinoma of the bladder confirm that methotrexate is active as a single agent. Over-all, 43 per cent of the patients with measurable metastases and 28 per cent with recurrent primary tumors responded for an average of 6 months. Response rates in both groups were influenced by the stage of the primary tumor.

The correlation of T1 bladder tumour history with prognosis and follow-up requirements.

The histories of 332 T1 bladder cancer patients were studied to determine the natural history in this tumour population. Each was followed for at least 5 years or to earlier tumour death and the approach to treatment was conservative. Patients were potentially at serious risk of disease progression and death if they presented with tumours of G2 or G3 grade and grew new ones again after treatment or if they exhibited a continuous high level of tumor neogenesis. Fourteen developed urothelial tumours beyond the bladder, evidence of widespread urothelial instability. Tumour deaths accounted for only 12% of the series, justifying a conservative approach to treatment, and a further 25% died from unrelated causes. Those remaining tumour-free at 5 years had a low malignant potential and their natural history supported discontinuing routine cystoscopy after that time.

Early multiple-dose adjuvant thiotepa in the control of multiple and rapid T1 tumour neogenesis.

In 45 patients each with a well established and constant pattern of widespread tumor neogenesis following cystodiathermy, early multiple dose adjuvant thiotepa was used in an effort to control the tumours. The response was good in 32 patients as judged by the reduction in the number of new tumours and by the downgrading and downstaging of new lesions when compared with pre-thiotepa histology. Continuing maintenance therapy was required in the majority but, with the passage of time, the dosage could be progressively reduced, suggesting a cumulative effect of treatment. Of 13 non-responders, 7 showed evidence of higher than average malignant potential against which thiotepa appears ineffective. The timing of administration is probably a key factor in success and one which accounts for much of the variation in reported results.

T3 bladder cancer--the case for salvage cystectomy.

Seven hundred and four patients with bladder cancer treated by radiotherapy at the London Hospital between 1965 and 1974 have been followed for a minimum period of 5 years. Invasive tumours were usually treated by radical radiotherapy. Cystectomy was reserved for patients whose tumours did not respond to radiation, recurred later on, or who developed complications from radiotherapy. The crude 5-year survival rate for T3 tumours in this series was 38%--similar to that obtained in other centres using pre-operative radiation followed by cystectomy, but this overall figure conceals the important difference between 2 distinct tumour populations. Nearly half of these tumours appear to be radiosensitive, giving a 56% crude 5-year survival rate for T3 tumours. The remainder are radioinsensitive, with only a 17% crude 5-year survival rate for T3 tumours. When there is a good initial response to radiotherapy there would seem to be no necessity to insist upon cystectomy.

The effects of epidural anesthesia on the urethral closure pressure profile in patients with prostatic enlargement.

In 10 patients with obstructive manifestations of prostatic enlargement the urethral closure pressure profile was observed before and after the effective blockade of thoracolumbar sympathetic outflow by epidural anesthesia. While epidural anesthesia significantly decreased urethral closure pressure considerable profile responses still remained in these patients. This fact suggests that the bulk of the prostatic tissue is responsible for the bladder outlet obstruction, since urethral closure pressure persists despite urethral smooth and skeletal muscular relaxation as a result of epidural anesthesia. After transurethral resection of the prostatic tissue in these patients the urethral closure pressure did decrease to zero. The result of the prostatic resection is to decrease the urethral closure pressure and, thereby, increase the efficiency of voiding.

A critical evaluation of the results of transurethral resection of the prostate.

In a review of 1057 consecutive prostatectomies of which 95% were performed transurethrally, carcinoma was present in 11.8%. There were 10 deaths within a month of operation (0.9%), 9 of these patients having been exceptionally old and unfit. The rate of complications and the end results appear to justify using transurethral resection as the method of choice for prostatectomy whenever it is feasible.

The effects of overstretching on the structure and function of the bladder in relation to Helmstein's distension therapy.

Measurements of the maximum bladder distensibility, cystometrograms and histological studies of the bladder after Helmstein's distension therapy show intramural fibrosis and a reduction in bladder capacity. When this is made worse by post-radiation fibrosis it may give rise to such severe contraction that diversion may be needed. There is no evidence that distension, of the type used here, ever gives rise to "stretching" or "atony" of the bladder: and it is questionable whether distension of a lesser degree, such as may be found in acute urinary retention, ever does so either.