Intermittent androgen deprivation after PSA-complete response as a strategy to reduce induction of hormone-resistant prostate cancer

OBJECTIVES

The increasing interest in exploring the use of intermittent androgen deprivation in prostate cancer has prompted a retrospective review of patients who elected to stop treatment.

METHODS

Case records were reviewed.

RESULTS

Twenty patients after 3 to 48 months (median 12) of endocrine therapy elected to stop therapy. Thirteen subsequently relapsed after a median observation of 9 months. Seven of 20 patients continue progression-free for 9 to 42 months (median 33). After second-line therapy, 75% of patients with a relapse remain progression-free at 2 years. Progression-free survival was higher in patients at Stage M0 (82% at 1 year) versus M+ (29% at 1 year).

CONCLUSIONS

With 10 of 13 patients demonstrating an ongoing second PSA response, 45% of patients showing no progression, and 85% alive at 3 years, these results support findings from previous publications that suggest that there are no major risks with use of intermittent hormone therapy. However, in the future, there is an urgent need that such studies should be randomized and done in the context of audit-based research and development programs. The resources released could then be invested with respect to further improvements in treatment of prostate cancer, possibly considering such a combined approach with immunotherapy as an alternative to surgery or radiotherapy for early disease in elderly patients with long PSA-doubling time.

Neurobiology

The role of neuropeptide Y (NPY), leptin and 5-HT and other neurotransmitters implicated in the regulation of energy balance are only now being fully investigated. Little is known about how they may interact with each other in this complex process. In evolutionary terms, the availability of excess food, and the risk of obesity, is only a recent occurrence in humans. Man, and perhaps other species, may not have developed a specialised neurochemical system for adjusting food intake during obesity. Hence perturbation of a single system, such as hypothalamic NPY or leptin, is unlikely to be directly responsible for the development of most obesity. In contrast, periods of food deprivation and partial starvation have been common in the animal kingdom and the multitude of neurotransmitters implicated in energy balance are more likely to be directed towards increasing food consumption and conserving energy than reducing appetite and increasing thermogenesis in the presence of excess. The last few years have witnessed rapid advances in the understanding of the fundamental mechanisms that regulate body weight and fat content. This progress will undoubtedly continue in the future, and it is hoped that this will be rewarded with the development of new drugs to treat obesity. At present, however, it is unclear whether NPY, leptin, or other apparently strong candidates will be the winner in the lucrative race for the ideal anti-obesity drug.

Female urethral diverticula

Most urethral diverticula should be diagnosed on clinical grounds alone, but investigations may be used to confirm the diagnosis in difficult cases, delineate the extent of the disease and investigate other entities such as stress incontinence. A high index of suspicion is required when assessing women with lower urinary tract symptoms to ensure that cases of urethral diverticulum are not missed. The cases presented demonstrate that greater awareness of the signs and symptoms of this not uncommon disease may facilitate early diagnosis. Our cases also show that surgical treatment is effective and worthwhile.

Microsatellite instability in early onset and familial colorectal cancer

Hereditary non-polyposis colorectal cancer syndrome (HNPCC) is often considered to be the most common form of inherited colorectal cancer, although its precise incidence is unknown. The clinical diagnosis of HNPCC relies on a combination of family history and young age of onset of colorectal cancer, but as many familial aggregations of colorectal cancer do not fulfil the strict diagnostic criteria, HNPCC might be underdiagnosed. The majority of HNPCC families have germline mutations in mismatch repair (MMR) genes, such as MSH2 or MLH1, so that HNPCC cancers characteristically exhibit DNA replication errors (RERs) at microsatellite loci. Although an RER positive phenotype in tumours can also result from somatic mutations in an MMR gene, the prevalence of RER + tumours should provide a maximum estimate of the incidence of germline MMR gene mutations in patients with early onset and familial colorectal cancer. We investigated colorectal cancers for RERs from (1) a population based study of 33 patients with colorectal cancer aged 45 years or less, (2) 65 kindreds with familial colorectal cancer which only partially fulfilled the criteria for the diagnosis of HNPCC, and (3) 18 cancers from 12 HNPCC kindreds. Seven of 33 patients (21%) with colorectal cancer aged 45 years or less had an RER + cancer, with only two of these having a clear family history of HNPCC. A greater proportion of RER + tumours (5/7) occurred proximal to the splenic flexure than RER - tumours (4/26; chi2 = 6.14, p < 0.025). RERs were detected in all 18 cancers from HNPCC patients but in only six of 65 non-HNPCC familial colorectal cancer kindreds (9%; chi2 = 52.2, p < 0.0005). These findings suggest that most cancers in patients diagnosed at 45 years of age or less and familial aggregations of colorectal cancer which do not fulfil HNPCC diagnostic criteria do not have germline mutations in MSH2 and MLH1. Hence population screening for germline mutations in these genes is unlikely to be an efficient strategy for identifying people at high risk of developing colorectal cancer.

Expression of the inducible nitric oxide synthase gene in diaphragm and skeletal muscle

Nitric oxide (NO) is a pluripotent molecule that can be secreted by skeletal muscle through the activity of the neuronal constitutive isoform of NO synthase. To determine whether skeletal muscle and diaphragm might also express the macrophage-inducible form of NO synthase (iNOS) during provocative states, we examined tissue from mice at serial times after intravenous administration of Escherichia coli endotoxin. In these studies, iNOS mRNA was strongly expressed in the diaphragm and skeletal muscle of mice 4 h after intravenous endotoxin and was significantly diminished by 8 h after challenge. Induction of iNOS mRNA was followed by expression of iNOS immunoreactive protein on Western immunoblots. Increased iNOS activity was demonstrated by conversion of arginine to citrulline. Immunochemical analysis of diaphragmatic explants exposed to endotoxin in vitro revealed specific iNOS staining in myocytes, in addition to macrophages and endothelium. These results may be important in understanding the pathogenesis of respiratory pump failure during septic shock, as well as skeletal muscle injury during inflammation or metabolic stress.

Interferon beta-1b decreases the migration of T lymphocytes in vitro: effects on matrix metalloproteinase-9

In multiple sclerosis (MS), the influx of activated T lymphocytes into the brain parenchyma leads to the subsequent damage of oligodendrocytes, the cells that produce central nervous system (CNS) myelin. We report here that interferon beta-1b (IFNbeta-1b), a drug shown to be efficacious in the treatment of patients with MS, decreases the in vitro migration of activated T lymphocytes through fibronectin (FN), a major component of the basement membrane that surrounds cerebral endothelium. At 1,000 IU/ml, IFNbeta-1b reduced the migratory rate to that of unactivated T cells. In contrast, IFNgamma at 1,000 IU/ml, which caused a similar decrease (25%) in the proliferation rate of T lymphocytes as IFNbeta-1b, did not affect migration. All T-lymphocyte subsets and natural killer (NK) cells were demonstrated by flow cytometry to be equally affected by IFNbeta-1b treatment. 125I-Western blot analyses revealed that IFNbeta-1b treatment resulted in a marked reduction of the ability of T cells to cleave FN. The substrate-degrading capability of T lymphocytes was shown to be due predominantly to the activity of a 92-kd matrix metalloproteinase, MMP-9, whose levels were decreased by IFNbeta-1b. We suggest that the clinical benefits of IFNbeta-1b treatment in MS patients may be in part a result of the ability of this drug to significantly decrease MMP-9 activity, leading to a reduction of T-lymphocyte infiltration into the CNS.

Endoscopic laser ablation of the prostate (ELAP): changes in magnetic resonance imaging and clinical outcome at 1 year

OBJECTIVE

To assess the ability of magnetic resonance imaging (MRI) to detect tissue changes immediately after laser ablation of the prostate and to correlate these changes with clinical outcome by detecting changes that may improve the outcome by allowing the laser dosimetry to be adjusted during therapy by monitoring effects on gland morphology.

PATIENTS AND METHODS

Eight men with proven bladder outlet obstruction had a standard four-quadrant laser ablation of the prostate with a side-firing non-contact fibre. MRI scans were performed before, during and immediately after treatment and again after one week, 3 months and one year.

RESULTS

The clinical outcome was a decrease in the American Urological Association (AUA)-7 symptom score from a pre-operative mean of 21.3-12.0 1 year after treatment and a corresponding increase in peak urinary flow rates from a mean of 8.9 mL/s to 12.3 mL/s. Immediately after treatment, MRI showed marked swelling of the gland (mean increase in volume 34%, range 12-75) with the loss of internal architecture. A low-signal thin periurethral band was present in six of the eight patients after 1 week and was replaced by a wider periurethral ring at 3 months in four of the six patients. No patient had evidence of prostatic cavitation after treatment or a significant reduction in prostate volume at 1 year.

CONCLUSION

MRI can detect tissue changes after laser ablation of the prostate. The marked swelling seen on MRI immediately after laser prostatectomy may explain the delayed improvement in symptoms. The periurethral ring may indicate the depth to which laser energy has an effect on the tissue and could delineate an area of necrosis. The lack of cavitation at one year questions the durability of the effect of laser treatment delivered in this way.

Long-term follow-up of patients with erectile dysfunction commenced on self injection with intracavernosal papaverine with or without phentolamine

OBJECTIVES

To determine the usage, complications and satisfaction with intracavernosal agents in patients with erectile dysfunction commenced on self-injection treatment at home.

PATIENTS AND METHODS

A total of 344 patients who had commenced intracavernosal treatment before December 1992 and had requested a repeat prescription were sent a questionnaire to determine the usage, complications, satisfaction and reasons for discontinuing treatment.

RESULTS

Replies were received from 216 patients; of those who replied, only 126 were still using the treatment. The mean duration of treatment was 3.9 years in those continuing treatment. Whilst satisfaction ratings were high in those continuing therapy, most patients had experienced some side-effects.

CONCLUSION

The long-term follow-up revealed a high attrition rate and a significant number of complications. Patients receiving auto-injection therapy should be offered regular long-term follow-up.

Do cyclosporin profiles provide useful information in the management of renal transplant recipients?

BACKGROUND

This study investigated the relationships between cyclosporin A (CsA) blood levels and episodes of renal allograft rejection and nephrotoxicity following renal transplantation, with the aim of establishing whether CsA profiles provided more useful information than single CsA blood levels in respect of these relationships.

METHODS

One hundred and sixty-two profiles were performed over 16 months in 40 patients and analysed retrospectively. Blood samples were taken at 0, 2, 4, 6 and 8 h after the morning CsA dose. Rejection episodes were diagnosed by renal biopsy and CsA nephrotoxicity by a fall in serum creatinine 1 week after a cut in CsA dose.

RESULTS

The mean area under the curve (AUC) was lower for profiles performed at the time of rejection (3821 h.ng/ml) than that of a matched group of non-rejecting profiles (5479 h.ng/ml; P < 0.02). An AUC above 6400 h.ng/ml significantly discriminated rejection from non-rejection, whereas pre-dose and peak CsA concentrations did not have such discriminating cut-off values. A comparison of CsA-toxic and non-toxic profiles showed that there were no significant differences between mean CsA concentrations nor between the mean AUCs of these groups.

CONCLUSION

We conclude that basing CsA dosing on CsA profiles could help to avoid some early episodes of rejection without increasing the risk of nephrotoxicity.

MMPI-2 patterns in African-American females

Researchers have reported conflicting conclusions about the relation of the MMPI (MMPI-2) clinical scale elevations and race. Consequently, this study examined the concurrent validity of the MMPI-2 in evaluating African-American females. Seventy-eight (78) African American college student volunteers were administered the MMPI-2, along with other measures of personality, achievement, and coping style. Scores revealed 76% of the sample had elevated profiles. Subjects were divided into three groups based on frequency of clinical scale code type. Subjects with the 5/9 profile elevations functioned as well as normals on measures of coping skills and mood disorders. Discussion emphasizes the importance of clinical interpretation of MMPI data in research programs and the relationship of the data to coping style.

Dissociation of body-temperature and melatonin secretion circadian rhythms in patients with chronic fatigue syndrome

Many patients with chronic fatigue syndrome (CFS) display features of hypothalamic dysfunction. We have investigated aspects of circadian rhythmicity, an important hypothalamic function, in 20 CFS patients and in 17 age- and sex-matched healthy control subjects. There were no differences between the two groups in the amplitude, mesor (mean value) or timing of the peak (acrophase) of the circadian rhythm of core temperature, or in the timing of the onset of melatonin secretion. However, the CFS patients showed no significant correlation between the timing of the temperature acrophase and the melatonin onset (P < 0.5), whereas the normal significant correlation was observed in the controls (P < 0.05). Dissociation of circadian rhythms could be due to the sleep deprivation and social disruption, and/or the reduction in physical activity which typically accompany CFS. By analogy with jet-lag and shift-working, circadian dysrhythmia could be an important factor in initiating and perpetuating the cardinal symptoms of CFS, notably tiredness, impaired concentration and intellectual impairment.

Increased feeding and neuropeptide Y (NPY) but not NPY mRNA levels in the hypothalamus of the rat following central administration of the serotonin synthesis inhibitor p-chlorophenylalanine

Neurons containing serotonin (5-HT), a potent anorexic agent, come into contact with neuropeptide Y-ergic neurons, that project from the arcuate nucleus (ARC) to the paraventricular nucleus (PVN). NPY powerfully stimulates feeding and induces obesity when injected repeatedly into PVN. We hypothesize that 5-HT tonically inhibits the ARC-PVN neurons and that balance between the two systems determines feeding and energy homeostasis. This study aimed to determine whether central injection of the 5-HT synthesis inhibitor p-chlorophenylalanine (pCPA), which increases feeding, increased hypothalamic NPY and NPY mRNA levels. pCPA (10 mg/kg in 3 microliters) was administered into the third ventricle either as a single injection (n = 8) or daily for 7 days (n = 8). Control rats received a similar injection of saline. pCPA significantly increased food intake compared with controls after both single and repeated injections (P < 0.05). NPY levels were measured by radioimmunoassay in microdissected hypothalamic extracts. NPY levels in the acutely treated group were significantly increased in the paraventricular nucleus (PVN; by 41%, P = 0.01), anterior hypothalamic area (AHA; by 34%, P < 0.01) and lateral hypothalamic area (LHA; by 41%, P < 0.02). In the 7-day-treated group, NPY levels were also increased in the same areas, i.e. PVN (by 24%, P < 0.01), AHA (by 30%, P < 0.01) and LHA (by 38%, P = 0.01). There were no significant changes in the ARC or any other region or in hypothalamic NPY mRNA levels. pCPA administration increased NPY levels in several regions notably the PVN. This is a major site of NPY release, where NPY injection induces feeding. We suggest that the hyperphagia induced by pCPA is mediated by increased NPY levels and secretion in the PVN. This is further evidence for interactions between NPY and 5-HT in the control of energy homeostasis.

Selective renal transplantation in primary hyperoxaluria type 1

Primary hyperoxaluria type I (PHI) is a cause of end-stage renal disease in young people. It is caused by deficient activity of hepatic peroxisomal alanine:glyoxylate aminotransferase (AGT), which results in hyperoxalemia and hyperoxaluria. The consequent urolithiasis and nephrocalcinosis result in renal impairment, with further reduction in oxalate excretion and eventual systemic oxalosis. Historically, renal transplantation has yielded very poor results in these patients because of recurrent oxalosis of the graft. Within the last 10 years, combined hepatorenal transplantation has been successfully applied, simultaneously correcting the metabolic lesion in the liver and replacing the damaged kidneys. It has, however, become apparent that medical therapy with vigorous hydration, inhibitors of stone formation and pyridoxine (AGT co-factor), may be successful at delaying, and occasionally in preventing, urolithiasis in some hyperoxaluric patients, particularly those whose hyperoxaluria is reduced by pyridoxine. This, together with intensive perioperative management and modern surgical methods of stone management such as lithotripsy, laser or ultrasound stone fragmentation, and percutaneous nephrolithotomy, means that renal transplantation alone may be feasible in selected patients. We describe a patient with PHI with clinical and biochemical evidence of significant residual AGT activity who underwent a successful live-related renal transplantation with excellent renal function and no stone recurrence 1 year posttransplantation. The appropriate transplantation strategies for these complex patients are discussed and include isolated renal transplantation for those patients who are without significant systemic oxalosis and have evidence of residual AGT activity.

The serotonergic agent fluoxetine reduces neuropeptide Y levels and neuropeptide Y secretion in the hypothalamus of lean and obese rats

Evidence suggests that serotonin and neuropeptide Y neurons in the hypothalamus, which respectively inhibit and stimulate food intake, may interact to control energy homoeostasis. We therefore investigated the effects of fluoxetine, which inhibits serotonin reuptake, on food intake and the activity of the neuropeptide Yergic arcuato-paraventricular projection in lean Wistar and Zucker rats. We also studied its effects in obese Zucker rats, in which obesity is postulated to be due to overactivity of the arcuato-paraventricular projection. Fluoxetine significantly reduced food intake in lean and obese rats, both during continuous subcutaneous infusion and (10 mg/kg/day for seven days) and acutely after a single injection (10 mg/kg). Fluoxetine also significantly reduced neuropeptide Y levels in the paraventricular nucleus, a major site of neuropeptide Y release which is highly sensitive to the appetite-stimulating actions of neuropeptide Y. Push-pull sampling in lean and fatty Zucker rats showed that neuropeptide Y secretion in the paraventricular nucleus was significantly reduced after acute fluoxetine treatment. Furthermore, seven days fluoxetine treatment prevented the significant increases in hypothalamic neuropeptide Y messenger RNA which were induced in lean rats by food restriction which precisely matched the hypophagia induced by the drug. We conclude that fluoxetine inhibits various aspects of the activity of the neuropeptide Yergic arcuato-paraventricular neurons, and suggest that reduced neuropeptide Y release in the paraventricular nucleus may mediate, at least in part, the drug's hypophagic action. We further suggest that serotonin may influence food intake and energy balance by inhibiting the arcuato-paraventricular projection, and that the two neurotransmitters may act together to regulate feeding and energy homoeostasis.