Use of non-steroidal anti-inflammatory drugs and prostate cancer risk: a population-based nested case-control study

Background

Despite strong laboratory evidence that non-steroidal anti-inflammatory drugs (NSAIDs) could prevent prostate cancer, epidemiological studies have so far reported conflicting results. Most studies were limited by lack of information on dosage and duration of use of the different classes of NSAIDs.

Methods

We conducted a nested case-control study using data from Saskatchewan Prescription Drug Plan (SPDP) and Cancer Registry to examine the effects of dose and duration of use of five classes of NSAIDs on prostate cancer risk. Cases (N = 9,007) were men aged ≥40 years diagnosed with prostatic carcinoma between 1985 and 2000, and were matched to four controls on age and duration of SPDP membership. Detailed histories of exposure to prescription NSAIDs and other drugs were obtained from the SPDP.

Results

Any use of propionates (e.g., ibuprofen, naproxen) was associated with a modest reduction in prostate cancer risk (Odds ratio = 0.90; 95%CI 0.84-0.95), whereas use of other NSAIDs was not. In particular, we did not observe the hypothesized inverse association with aspirin use (1.01; 0.95–1.07). There was no clear evidence of dose-response or duration-response relationships for any of the examined NSAID classes.

Conclusions

Our findings suggest modest benefits of at least some NSAIDs in reducing prostate cancer risk.

Xenopus embryos lacking specific isoforms of the corepressor SMRT develop abnormal heads

The corepressor SMRT acts on a range of transcription factors, including the retinoid and thyroid hormone nuclear receptors. The carboxy-terminal region of SMRT contains CoRNR box motifs that mediate these interactions. We have shown, in Xenopus, that SMRT can exist as isoforms containing either two or three CoRNR boxes depending on the alternative splicing of exon 37b. The number of SMRT transcript isoforms expressed increases during development until all sixteen possible isoforms are identified in the swimming tadpole. To eliminate specific SMRT isoforms, we have developed a process that uses an antisense morpholino oligonucleotide in Xenopus to dictate the outcome of alternative splicing at a defined exon and used this to inhibit the formation of transcripts containing exon 37b. These embryos are therefore limited to the expression of SMRT isoforms that contain two rather than three CoRNR boxes. Analysis of responsive genes in these embryos shows that targets of thyroid hormone, but not retinoid signaling are affected by the elimination of exon 37b. Morpholino-injected embryos have swimming abnormalities and develop altered head morphology, an expanded olfactory epithelium and disorganized peripheral axons. These experiments indicate a critical role for the alternative splicing of SMRT in development.

Developmental and Tissue Expression ofXenopus laevis RPGR

PURPOSE

The present study examined the developmental and tissue expression of the retinitis pigmentosa GTPase regulator (RPGR) gene in Xenopus laevis.

METHODS

The cDNA for X. laevis RPGR (XRPGR) was isolated from adult eye mRNA by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends. The deduced peptide sequence was aligned with RPGR orthologues. Gene expression was examined by whole-mount in situ hybridization and RT-PCR. The localization of XRPGR in X. laevis photoreceptor cells and XTC-2 cells was determined by immunostaining.

RESULTS

The XRPGR(ex1-19) isoform encodes a protein of 727 amino acids containing an RCC1 domain and a C-terminal isoprenylation anchorage motif. It shares 33% to 41% amino acid identity with human, mouse, and dog RPGR. The C-terminal exon of the alternatively spliced RPGR(ORF15) isoform is also conserved across species. XRPGR is expressed at the earliest stages of X. laevis development and persists into adulthood, where expression is highest in the eye. XRPGR is expressed in presumptive eye fields (stages 18 to 22), becoming largely restricted to the central retina (stages 28 to 40). XRPGR protein colocalizes with beta-tubulin at the X. laevis ciliary axoneme and with gamma-tubulin at centrosomes in XTC-2 cells.

CONCLUSIONS

XRPGR is widely expressed throughout development but shows highest expression after the appearance of the eye primordium and persists in the eye into adulthood. The data are consistent with XRPGR expression in a single microtubular organelle-the centriole or basal body and associated ciliary transitional zone found in modified sensory cilia of photoreceptors and motile cilia.

SMRT has tissue-specific isoform profiles that include a form containing one CoRNR box

SMRT acts as a corepressor for a range of transcription factors. The amino-terminal part of the protein includes domains that mainly mediate transcriptional repression whilst the carboxy-terminal part includes domains that interact with nuclear receptors using up to three motifs called CoRNR boxes. The region of the SMRT primary transcript encoding the interaction domains is subject to alternative splicing that varies the inclusion of the third CoRNR box. The profile in mice includes an abundant, novel SMRT isoform that possesses just one CoRNR box. Mouse tissues therefore express SMRT isoforms containing one, two or three CoRNR boxes. In frogs, the SMRT isoform profile is tissue-specific. The mouse also shows distinct profiles generated by differential expression levels of the SMRT transcript isoforms. The formation of multiple SMRT isoforms and their tissue-specific regulation indicates a mechanism, whereby cells can define the repertoire of transcription factors regulated by SMRT.

Alternative splicing generates multiple SMRT transcripts encoding conserved repressor domains linked to variable transcription factor interaction domains

Silencing mediator for retinoid and thyroid hormone receptor (SMRT) and nuclear receptor corepressor protein (NCoR) are corepressors that interact with a range of transcription factors. They both consist of N-terminal repressor domains that associate with histone deacetylases and C-terminal interaction domains (IDs) that contain CoRNR box motifs. These motifs mediate the interaction between corepressors and nuclear receptors (NRs), such as the retinoid and thyroid hormone receptors. However, whilst NCoR produces a single transcript during Xenopus development, xSMRT is subject to alternative splicing at four sites in the 3' part of the transcript, the region encoding the C-terminal IDs. Although this provides the potential to produce 16 different transcripts, only five isoforms are found in early embryos. The sites of alternative splicing predict that the resultant isoforms will differ in their ability to interact with NRs, as one site varies the number of CoRNR boxes, the second site changes the sequence flanking CoRNR box-1 and the other sites delete amino acid residues between CoRNR boxes 1 and 2 and so alter the critical spacing between these motifs. SMRT and NCoR therefore represent paralogues in which one form, SMRT, has evolved the ability to generate multiple isoforms whereas the other, NCoR, is invariant in Xenopus development.

Outcomes of infants born to mothers receiving methadone for pain management in pregnancy

OBJECTIVE

To assess the outcomes of infants born to mothers receiving methadone for the management of pain in pregnancy.

DESIGN

A retrospective audit was conducted of neonatal outcomes in 19 cases in which methadone was used in the management of maternal pain (pain group). Twenty four cases in which methadone was used for maintenance of opiate addiction in pregnancy served as a comparison group (maintenance group).

SETTING

Regional level 3 neonatal service.

RESULTS

Infants in the pain group were exposed to significantly smaller methadone doses, for shorter periods, starting later in pregnancy. Only 11% of them required treatment for neonatal abstinence syndrome, whereas 58% of infants in the maintenance group required treatment. Other neonatal morbidity in the pain group was considerable, probably related to prematurity. Infants in the pain group had significantly higher z scores for birth weight and head circumference, but not length, than the infants in the maintenance group.

CONCLUSIONS

Methadone used for the treatment of maternal pain resulted in a low incidence of neonatal abstinence syndrome. Infants were normally grown. However, there was significant morbidity related to slight prematurity, and delivery in this group should be delayed until term if possible.

Characterization of matrix metalloprotease activities induced in the sea urchin extraembryonic matrix, the hyaline layer

Hyaline layers, freshly prepared from one-hour-old embryos, were devoid of gelatin-cleavage activity. However, upon storage at 4 degrees C, gelatin-cleavage activities appeared; three species of apparent mol mass 94 --> 117-, 90-, and 45-kDa were seen. All three species required zinc for activity. Using gel-exclusion chromatography we separated the 94 --> 117-, and 90-kDa species from the 45-kDa activity. The two higher mol mass species were inhibited by ethylenebis (oxyethylenenitrilo) tetraacetic acid and the lost activity was restored by calcium. Reconstitution of activity occurred with an apparent dissociation constant (calcium) of 5 microM. The presence of millimolar concentrations of magnesium had a minimal inhibitory effect on activity. The thermal denaturation profile of the higher mol mass gelatin-cleavage activity was significantly different in the presence and absence of calcium. Stabilization of these activities against thermal denaturation at 60 degrees C occurred with an apparent dissociation constant (calcium) of 0.6 mM. Magnesium had no significant effect on the thermal denaturation profile. Collectively, these results suggest at least two different modes of interaction between calcium and the higher mol mass gelatinases. These conclusions are discussed in the context of the high calcium and magnesium concentrations present in the sea water environment of the sea urchin embryo.

Wnt signalling: a theme with nuclear variations

Wnt proteins are involved in a large number of events during development and disease. The crucial element in the transduction of the signal elicited by Wnt is the state and activity of beta-catenin. There are two pools of beta-catenin, one associated with cadherins at the cell surface and a soluble one in the cytolasm, whose state and concentration are critical for Wnt signalling. In the absence of Wnt, the cytoplasmic pool is low due to targetted degradation of beta-catenin. Upon Wnt signalling, beta-catenin is stabilized. As a consequence, it can access the nucleus where it interacts with members of the Tcf family of transcription factors to modulate the expression of defined targets. Recent reports indicate that, in addition to Tcfs, beta-catenin can interact with other nuclear proteins raising the possibility that Wnt signalling has a wider modulatory effect on transcription than is mediated by its interactions with Tcfs. BioEssays 23:311-318, 2001.

Retinoid signalling acts during the gastrula stages to promote primary neurogenesis

Retinoid signalling has been manipulated at different developmental stages to identify a critical period in the gastrula embryo for retinoid-dependent primary neurone formation. The expression of retinoid receptor RARalpha2 in the posterior neuroectoderm of the gastrula embryo is therefore consistent with a role in primary neurogenesis. In addition we show that the expression of neurogenin-1 and XDelta-1, two genes that contribute to the determination of primary neurone cell-fate in the gastrula embryo, respond to retinoid signalling. These results indicate that retinoid signalling is required for an early step in the process of primary neurogenesis. When retinoid signalling is increased, the number of primary neurones increases, but the phenotype is not the same as the neurogenic phenotype that follows the overexpression of a dominant negative form of XDelta-1. Whereas increased retinoid signalling expands the width of primary neurone stripes, dominant negative XDelta-1 increases the density of primary neurones within the stripes. When retinoid signalling is increased and the primary neurone stripes expand, the expression domain of a floorplate marker contracts. Conversely, when retinoid signalling is inhibited, the expression patterns of floorplate markers widen. These results indicate that retinoid signalling acts at an early stage in primary neural development when the fates of different regions of the neuroectoderm are being determined.

The control of Xenopus embryonic primary neurogenesis is mediated by retinoid signalling in the neurectoderm

In Xenopus, the primary neurons form in three domains either side of the midline in the posterior neurectoderm. At the late neurula stage there are approximately 120 primary sensory neurons on each side of the embryo. Co-injecting synthetic mRNA encoding retinoic acid receptor alpha (NR1B1) and retinoid X receptor beta (NR2B2) results in an increase in the number of primary neurons and this is further enhanced by the addition of retinoic acid indicating that elevated retinoid signalling promotes an increase in the number of cells undergoing primary neurogenesis. However, primary neurogenesis remains confined to the three domains that normally give rise to primary neurons indicating that not all regions of the neurectoderm respond equivalently to elevated retinoid signalling. The inhibition of retinoid signalling with a dominant negative retinoid receptor or treatment with citral, an inhibitor of retinoid metabolism, inhibits the formation of primary neurons. However, the lateral extent of the neurectoderm does not differ following these experimental manipulations suggesting that changes in primary neuron cell number, in response to changes in retinoid signalling, cannot be accounted for by significant gains or losses of neurectoderm. In addition, two lines of evidence are presented to suggest that retinoid signalling affects primary neurogenesis by acting directly on the neurectoderm. First, animal caps neuralized by noggin undergo primary neurogenesis in response to retinoid signalling and second primary neurogenesis is elevated in neural conjugates in which the ectodermal, but not the mesodermal, component has been co-injected with RAR/RXR mRNA.

Cellulite treatment: a myth or reality: a prospective randomized, controlled trial of two therapies, endermologie and aminophylline cream

Cellulite is a common phenomenon that particularly affects the thighs and buttocks of women. Little scientific evidence exists to support any of the many advertised treatments for it. A total of 52 of 69 women, who were divided into three groups, completed a 12-week, randomized, controlled trial in which the effectiveness of two different treatments for cellulite was assessed. The patients acted as their own controls. The treatments investigated were twice-daily application of aminophylline cream and twice-weekly treatment with Endermologie ES1. Group 1 (double blind) received aminophylline to one thigh/buttock and a placebo cream to the other. Group 2 (singly blind) received Endermologie to one thigh/buttock. Group 3 received Endermologie to both sides and used the same cream regimen as group 1. Results were assessed subjectively by the patient and by clinical examination and photographic assessment by the surgeon (before and after the trial). Morphologic assessment included body mass index, thigh girth at two points, and thigh fat depth measurement by ultrasound. No statistical difference existed in measurements between legs for any of the treatment groups (paired t test, p > 0.4). The best subjective assessment, by the patients themselves, revealed that only 3 of 35 aminophylline-treated legs and 10 of 35 Endermologie-treated legs had their cellulite appearance improved. The authors do not believe that either of these two treatments is effective in improving the appearance of cellulite.

Colorectal cancer prevention by non-steroidal anti-inflammatory drugs: effects of dosage and timing

Epidemiological studies show that non-steroidal anti-inflammatory drugs (NSAIDs) reduce colorectal cancer incidence. We measured the rate ratio for colorectal adenocarcinoma according to dosage and the timing of exposure by means of a case-control study, nested in a non-concurrent cohort linkage study, using the population of beneficiaries of the Saskatchewan Prescription Drug Plan from 1981 to 1995 with no history of cancer since 1970 as the source population. Four controls per case, matched on age and gender and alive when the case was diagnosed, were randomly selected. Dispensing rates, calculated over successive time periods, characterized NSAID exposure. We accrued 3844 cases of colon cancer and 1971 cases of rectal cancer. For colon cancer a significant trend towards a decreasing rate ratio was associated with increasing exposure during the 6 months preceding diagnosis (P-trend = 0.002). For both cancers, significant trends were associated with exposure 11-15 years before diagnosis (colon: P-trend = 0.01; rectum: P-trend = 0.0001). At the highest exposure levels the rate ratio for colon cancer was 0.57 (95% confidence interval (CI) 0.36-0.89); for rectal cancer it was 0.26 (95% CI 0.11-0.61). No protection was associated with exposure during other periods. The timing of NSAID use must be considered in planning intervention trials to prevent colorectal cancer. There may be a 10-year delay before any preventive effect will appear.

Controlling confounding when studying large pharmacoepidemiologic databases: a case study of the two-stage sampling design

Large drug databases have been the source of interesting developments for pharmacoepidemiologic research, because they provide relatively accurate drug exposure histories. An important limitation of these databases is the lack of information on potential confounders. One solution, developed more than a decade ago but not widely used, is "two-stage sampling," in which stage 1 is the collection of information on drug exposure and outcomes, and stage 2 is the collection of confounder data on a subset of the stage 1 sample. The balanced design, wherein an equal number of individuals is selected from each drug exposure/disease category, is usually the most efficient strategy by which to select the stage 2 sample. We illustrate the efficiency of the balanced design in two-stage sampling using data from a provincial health organization and a simulation. We also evaluate the relative importance of factors affecting the precision of the effect estimate of the exposure of interest.

Two-stage sampling for etiologic studies. Sample size and power

Preexisting computerized databases are potentially valuable sources of epidemiologic data. Since such databases are infrequently created specifically for etiologic research, data may be available for the exposure of interest and, through record linkage, for the endpoint of interest, but lacking for potential confounders. Because of the size of these databases, two-stage sampling is an efficient alternative to surveying the entire study population for confounder data. At stage 1, information on exposure and disease status is obtained for the entire study population. Confounder data are collected for probability-selected subsamples at stage 2. Logistic regression is performed on the stage 2 samples, with the parameter estimates and variances appropriately corrected to account for the stage 1 data. In this paper, the authors present methods for determining the required stage 2 sample size in the case of categorical exposure and confounding variables. Sample size tables, power curves, and a computer program have been produced to accommodate a binary exposure and a single binary confounder. With the increasing availability of preexisting yet incomplete databases, the potential for use of two-stage sampling will greatly increase in the future. This investigation provides a basis for estimating the number of participants to sample for the collection of confounder data at the second stage.

Perceived health, HIV illness, and mental distress in African-American clients of AIDS counseling centers

The development of effective coping strategies may require that adults with HIV disease have an accurate, and to the extent possible, positive perception of their own health status. This has been found to be lacking among HIV-infected people with limited education/information, including many minority adults. The objective of this study was to test several hypotheses that predict depression and perceived health in African-American adults with HIV disease. Data were obtained from 255 HIV-infected black adults (age > 18) who sought support, counseling, and maintenance services from one of three HIV care and referral centers in the Mid-South. The results emphasized that perceived health status may fulfill a psychological distress moderating or distress-aggravating function for persons with HIV/AIDS.

Juvenile myoclonic epilepsy: diagnosis, management and outcome

OBJECTIVES

To study delay in diagnosis, seizure control, seizure-provoking factors, suitable medications and drug side effects in patients with juvenile myoclonic epilepsy.

DESIGN

Telephone and personal interview of patients and review of their clinical notes.

PARTICIPANTS AND SETTING

Thirty-six patients attending an epilepsy clinic at a tertiary referral hospital.

RESULTS

There was a substantial delay in the diagnosis of juvenile myoclonic epilepsy because the symptom of early-morning myoclonus was not specifically sought. Sodium valproate is the drug of choice, producing absolute seizure control in 63% of cases (19/30). Most patients with poor seizure control had provoked seizures only, emphasising the importance of lifestyle in management. Half of the patients taking sodium valproate experienced side effects, such as weight gain. Lamotrigine is the most suitable alternative.

CONCLUSIONS

Juvenile myoclonic epilepsy is a common, under-recognised form of epilepsy which is best treated with sodium valproate. If side effects occur, lamotrigine should be used.

An evaluation of the action plans of children with asthma

OBJECTIVE

To assess the provision and use of action plans in children attending hospital because of asthma.

METHODOLOGY

An interviewer administered a structured questionnaire to the parents of 279 children attending the Casualty Department, Outpatient clinics or admitted to hospital because of asthma, at two Level 3 teaching hospitals.

RESULTS

Only 82 (29%) of the children attending hospital had a written action plan. The majority (57%) were devised by paediatricians and covered the salient aspects of care. However, indications for steroid use were included in only 28% of plans and only 37% of the action plans in children over 5 years incorporated the use of peak flow meters.

CONCLUSIONS

Action plans are still under-utilized in children with asthma. General practitioners should be encouraged to consider the use of action plans for the group of children not already covered.

Clonazepam withdrawal in 13 patients with active epilepsy and drug side effects

We report the end result of clonazepam (CZP) withdrawal in 13 patients with significant side effects felt to be due to CZP. The present observations supplement the recent report in Seizure by Chataway et al., in proposing a safe CZP withdrawal rate of 0.2 mg/day. Eight of the patients had withdrawal seizures, five had withdrawal symptoms and four patients had no withdrawal problems at all. Ultimately all the patients came off CZP, mainly quite rapidly (3-30 days) with the initial side effects regressing totally in 11 patients.