The dynamin-dependent, arrestin-independent internalization of 5-hydroxytryptamine 2A (5-HT2A) serotonin receptors reveals differential sorting of arrestins and 5-HT2A receptors during endocytosis

5-Hydroxytryptamine 2A (5-HT2A) receptors, a major site of action of clozapine and other atypical antipsychotic medications, are, paradoxically, internalized in vitro and in vivo by antagonists and agonists. The mechanisms responsible for this paradoxical regulation of 5-HT2A receptors are unknown. In this study, the arrestin and dynamin dependences of agonist- and antagonist-mediated internalization were investigated in live cells using green fluorescent protein (GFP)-tagged 5-HT2A receptors (SR2-GFP). Preliminary experiments indicated that GFP tagging of 5-HT2A receptors had no effect on either the binding affinities of several ligands or agonist efficacy. Likewise, both the native receptor and SR2-GFP were internalized via endosomes in vitro. Experiments with a dynamin dominant-negative mutant (dynamin K44A) demonstrated that both agonist- and antagonist-induced internalization were dynamin-dependent. By contrast, both the agonist- and antagonist-induced internalization of SR2-GFP were insensitive to three different arrestin (Arr) dominant-negative mutants (Arr-2 V53D, Arr-2-(319-418), and Arr-3-(284-409)). Interestingly, 5-HT2A receptor activation by agonists, but not antagonists, induced greater Arr-3 than Arr-2 translocation to the plasma membrane. Importantly, the agonist-induced internalization of 5-HT2A receptors was accompanied by differential sorting of Arr-2, Arr-3, and 5-HT2A receptors into distinct plasma membrane and intracellular compartments. The agonist-induced redistribution of Arr-2 and Arr-3 into intracellular vesicles and plasma membrane compartments distinct from those involved in 5-HT2A receptor internalization implies novel roles for Arr-2 and Arr-3 independent of 5-HT2A receptor internalization and desensitization.

Expression of expanded repeat androgen receptor produces neurologic disease in transgenic mice

Spinal and bulbar muscular atrophy (SBMA) is a motor neuron disease caused by the expansion of a polyglutamine tract within the androgen receptor. This disease is unusual among the polyglutamine diseases in that it involves lower motor and sensory neurons, with relative sparing of other brain structures. We describe the development of transgenic mice, created with a truncated, highly expanded androgen receptor driven by the neurofilament light chain promoter, which develop many of the motor symptoms of SBMA. In addition, transgenic mice created with the prion protein promoter develop widespread neurologic disease, reminiscent of juvenile forms of other polyglutamine diseases. Thus, in these experiments, the distribution of neurologic symptoms depends on the expression level and pattern of the promoter used, rather than on specific characteristics of androgen receptor metabolism or function. The transgenic mice described here develop neuronal intranuclear inclusions (NIIs), a hallmark of SBMA and the other polyglutamine diseases. We have shown these inclusions to be ubiquitinated and to sequester molecular chaperones, components of the 26S proteasome and the transcriptional activator CREB-binding protein. Apart from the presence of NIIs, evidence of neuropathology or neurogenic muscle atrophy was absent, suggesting that the neurologic phenotypes observed in these mice were the result of neuronal dysfunction rather than neuronal degeneration. These mice will provide a useful resource for characterizing specific aspects of motor neuron dysfunction, and for testing therapeutic strategies for this and other polyglutamine diseases.

Methadone advocacy: the voice of the patient

This decade will see great strides in the acceptance of methadone treatment for heroin addiction, as a result of clear scientific and clinical evidence of its efficacy, and strong methadone advocacy. The new proposal for rule making (NPRM) will help the medical profession accept methadone treatment as beneficial for opiate addiction and realize that it should be more accessible to patients from trained physicians in the community. This will be the first step in reducing the stigma and prejudice that continue to hinder the availability of this lifesaving medication to all who need it. Methadone advocacy has grown into a powerful network of groups working toward the same major goals. As the premier methadone advocacy organization and the voice for methadone patients, the National Alliance of Methadone Advocates (NAMA) will promote the view that methadone patients are to be judged by the contributions they make to their families and communities.

Needs and opportunities for improving the health, safety, and productivity of medical research facilities

Medical research facilities, indeed all the nation's constructed facilities, must be designed, operated, and maintained in a manner that supports the health, safety, and productivity of the occupants. The National Construction Goals, established by the National Science and Technology Council, envision substantial improvements in occupant health and worker productivity. The existing research and best practices case studies support this conclusion, but too frequently building industry professionals lack the knowledge to design, construct, operate, and maintain facilities at these optimum levels. There is a need for more research and more collaborative efforts between medical and facilities engineering researchers and practitioners in order to attain the National Construction Goals. Such collaborative efforts will simultaneously support attainment of the National Health Goals. This article is the summary report of the Healthy Buildings Committee for the Leadership Conference: Biomedical Facilities and the Environment sponsored by the National Institutes of Health, the National Association of Physicians for the Environment, and the Association of Higher Education Facilities Officers on 1--2 November 1999 in Bethesda, Maryland, USA.

A national census of ambulance response times to emergency calls in Ireland

BACKGROUND

Equity of access to appropriate pre-hospital emergency care is a core principle underlying an effective ambulance service. Care must be provided within a timeframe in which it is likely to be effective. A national census of response times to emergency and urgent calls in statutory ambulance services in Ireland was undertaken to assess current service provision.

METHODS

A prospective census of response times to all emergency and urgent calls was carried out in the nine ambulance services in the country over a period of one week. The times for call receipt, activation, arrival at and departure from scene and arrival at hospital were analysed. Crew type, location of call and distance from ambulance base were detailed. The type of incident leading to the call was recorded but no further clinical information was gathered. Results-2426 emergency calls were received by the services during the week. Fourteen per cent took five minutes or longer to activate (range 5-33%). Thirty eight per cent of emergencies received a response within nine minutes (range 10-47%). Only 4.5% of emergency calls originating greater than five miles from an ambulance station were responded to within nine minutes (range 0-10%). Median patient care times for "on call" crews were three times longer than "on duty" crews.

CONCLUSION

Without prioritized use of available resources, inappropriately delayed responses to critical incidents will continue. Recommendations are made to improve the effectiveness of emergency medical service utilisation.

Randomised comparison of the effectiveness and costs of community and hospital based mental health services for children with behavioural disorders

OBJECTIVE

To test the hypothesis that a community based intervention by secondary child and adolescent mental health services would be significantly more effective and less costly than a hospital based intervention.

DESIGN

Open study with two randomised parallel groups.

SETTING

Two health districts in the north of England.

PARTICIPANTS

Parents of 3 to 10 year old children with behavioural disorder who had been referred to child and adolescent mental health services.

INTERVENTION

Parental education groups.

MAIN OUTCOME MEASURES

Parents' and teachers' reports of the child's behaviour, parental depression, parental criticism of the child, impact of the child's behaviour on the family.

RESULTS

141 subjects were randomised to community (n=72) or hospital (n=69) treatment. Primary outcome data were obtained on 115 (82%) cases a year later. Intention to treat analyses showed no significant differences between the community and hospital based groups on any of the outcome measures, or on costs. Parental depression was common and predicted the child's outcome.

CONCLUSIONS

Location of child mental health services may be less important than the range of services that they provide, which should include effective treatment for parents' mental health problems.

Structure-based design and synthesis of phosphinate isosteres of phosphotyrosine for incorporation in Grb2-SH2 domain inhibitors. Part 2

A series of novel phosphinates, derived from 4-phosphonomethylphenylalanine, are described as isosteres of phosphotyrosine. Benzyl (or alkyl) phosphinomethylphenylalanine derivatives were prepared by alkylation of an amino acid P-H phosphinate.

Special feature for the Olympics: effects of exercise on the immune system: exercise-induced modulation of macrophage function

Macrophages are important effector cells involved in phagocytosis, microbial killing and antitumour activity. Macrophages also display accessory cell function, in that they can present antigen to foster the development of T lymphocyte-mediated immunity. Recent work, including studies from this group, has demonstrated that acute and chronic exercise can affect many facets of macrophage biology. Manifestation of these effects depends on exercise intensity and duration, the function measured, the timing of measurement in relation to exercise and the concentration of the macrophage-activating stimulus. Exercise has potent stimulatory effects on phagocytosis, antitumour activity, reactive oxygen and nitrogen metabolism, and chemotaxis. Indeed, it has been shown that exercise training can increase macrophage antitumour activity in mice of different ages. However, not all functions are enhanced by exercise. Exercise-induced reductions in macrophage MHC II expression and antigen-presentation capacity have been documented. These findings bring up the possibility that exercise, and perhaps other stressors, activate macrophages for effector functions while downregulating accessory cell functions. To a large extent, the mechanisms responsible for the exercise-induced changes in macrophage function remain unknown, but may depend on exercise-induced changes in neuroendocrine factors. Future studies need to explore the effects in a mechanistic way and provide documentation as to their physiological significance.

Efficacy of potential chemopreventive agents on rat colon aberrant crypt formation and progression

We assessed the effects of 78 potential chemopreventive agents in the F344 rat using two assays in which the inhibition of carcinogen-induced aberrant crypt foci (ACF) in the colon was the measure of efficacy. In both assays ACF were induced by the carcinogen azoxymethane (AOM) in F344 rats by two sequential weekly injections at a dose of 15 mg/kg. Two weeks after the last AOM injection, animals were evaluated for the number of aberrant crypts detected in methylene blue stained whole mounts of rat colon. In the initiation phase protocol agents were given during the period of AOM administration, whereas in the post-initiation assay the chemopreventive agent was introduced during the last 4 weeks of an 8 week assay, a time when ACF had progressed to multiple crypt clusters. The agents were derived from a priority listing based on reports of chemopreventive activity in the literature and/or efficacy data from in vitro models of carcinogenesis. During the initiation phase carboxyl amidoimidazole, p-chlorphenylacetate, chlorpheniramine maleate, D609, diclofenac, etoperidone, eicosatetraynoic acid, farnesol, ferulic acid, lycopene, meclizine, methionine, phenylhexylisothiocyanate, phenylbutyrate, piroxicam, 9-cis-retinoic acid, S-allylcysteine, taurine, tetracycline and verapamil were strong inhibitors of ACF. During the post-initiation phase aspirin, calcium glucarate, ketoprofen, piroxicam, 9-cis-retinoic acid, retinol and rutin inhibited the outgrowth of ACF into multiple crypt clusters. Based on these data, certain phytochemicals, antihistamines, non-steroidal anti-inflammatory drugs and retinoids show unique preclinical promise for chemoprevention of colon cancer, with the latter two drug classes particularly effective in the post-initiation phase of carcinogenesis.

Effect of intrauterine treatment with prostaglandin E2 prior to insemination of mares in the uterine horn or body

Two trials were conducted to investigate the effects of intrauterine infusion of PGE2 and uterine horn insemination on pregnancy rates in mares achieved by breeding with a suboptimal number of normal spermatozoa. Estrus was synchronized and mares were teased daily with a stallion to detect estrus. Mares in estrus were examined by transrectal palpation and ultrasonography to monitor follicular status. On the first day a 35-mm diameter follicle was present, hCG (1500 IU, iv) was administered and the mares were bred the next day. Mares (Trial 1, n = 34; Trial 2, n = 28) were inseminated with 25 million total spermatozoa from either a stallion with good semen quality (Trial 1) or poor semen quality (Trial 2). In each trial, mares were assigned to 1 of 4 treatment groups as follows: Group PGE-HI - infusion of 0.25 mg PGE2 into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the proximal end of the same uterine horn; Group PGE-BI - infusion of 0.25 mg PGE2 into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the uterine body; Group SAL-HI - infusion of 1 mL sterile saline into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the proximal end of the same uterine horn; or Group SAL-BI - infusion of 1 mL sterile saline into the proximal end of the uterine horn ipsilateral to the dominant follicle 2 h prior to insemination in the uterine body. After breeding, mares were examined daily by transrectal ultrasonography to confirm ovulation, and were re-examined 14 to 16 d after ovulation for pregnancy status. Data were analyzed by Chi-square. Overall pregnancy rates were 59% for stallion 1 and 29% for stallion 2. Group pregnancy rates did not differ for mares bred by either stallion (P > 0.10). Pregnancy rates were not altered by horn insemination for either stallion (P > 0.10). Intrauterine infusion of PGE2 improved pregnancy rate in mares bred by the stallion with good quality semen (P < 0.05), but did not alter pregnancy rate in mares bred by the stallion with poor quality semen (P > 0.10). Further research is warranted to determine if intrauterine infusion of PGE2 will enhance spermatozoal colonization of the oviduct and pregnancy rates in mares, and if PGE-treatment will improve pregnancy rates achieved by subfertile stallions.

An electronic menstrual cycle calendar: comparison of data quality with a paper version

OBJECTIVES

This pilot study compared a prototype electronic menstrual calendar on a handheld computer with a paper calendar for data quality and participants' perceptions.

DESIGN

Twenty-three women completed identical information about menstrual bleeding and symptoms using paper and electronic calendars for 1 month each.

RESULTS

Use of the paper calendar resulted in more missing data than the electronic calendar for bleeding characteristics (13% vs. 4%) and symptoms (35% vs. 4%). The electronic calendar's ability to log data entries revealed retrospective entry for 61% of the data. Total data entry and cleaning time was reduced by 81% with the electronic calendar. Overall, participants preferred the electronic (70%) to the paper (22%) calendar.

CONCLUSIONS

Data quality with conventional paper calendars may be poorer than recognized. The data-logging feature, unique to the electronic calendar, is critical for assessing data quality. Electronic menstrual calendars can be useful data collection tools for research in women's health.

A PPARgamma mutant serves as a dominant negative inhibitor of PPAR signaling and is localized in the nucleus

The peroxisomal proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily that act as ligand-activated transcription factors. PPARgamma plays a critical role in regulating adipocyte differentiation and lipid metabolism. Recently, thiazolidinedione (TZD) and select non-TZD antidiabetic agents have been identified as PPARgamma agonists. To further characterize this receptor subclass, a mutant hPPARgamma lacking five carboxyl-terminal amino acids was produced (hPPARgamma2Delta500). In COS-1 cells transfected with PPAR-responsive reporter constructs, the mutant receptor could not be activated by a potent PPARgamma agonist. When cotransfected with hPPARgamma2 or hPPARalpha, hPPARgamma2Delta500 abrogated wild-type receptor activity in a dose-responsive manner. hPPARgamma2Delta500 was also impaired with respect to binding of a high-affinity radioligand. In addition, its conformation was unaffected by normally saturating concentrations of PPARgamma agonist as determined by protease protection experiments. Electrophoretic mobility shift assays demonstrated that hPPARgamma2Delta500 and hPPARgamma2 both formed heterodimeric complexes with human retinoidxreceptor alpha (hRXRalpha) and could bind a peroxisome proliferator-responsive element (PPRE) with similar affinity. Therefore, hPPARgamma2Delta500 appears to repress PPAR activity by competing with wild type receptor to dimerize with RXR and bind the PPRE. In addition, the mutant receptor may titrate out factors required for PPAR-regulated transcriptional activation. Both hPPARgamma2 and hPPARgamma2Delta500 localized to the nucleus of transiently transfected COS-1 cells as determined by immunofluorescence using a PPARgamma-specific antibody. Thus, nuclear localization of PPARgamma occurs independently of its activation state. The dominant negative mutant, hPPARgamma2Delta500, may prove useful in further studies to characterize PPAR functions both in vitro and in vivo

Well-differentiated villoglandular adenocarcinoma of the uterine cervix: oncogene/tumor suppressor gene alterations and human papillomavirus genotyping

Twelve well-differentiated villoglandular adenocarcinomas (WDVAs) of the uterine cervix were retrospectively analyzed for the presence and specific genotype of human papillomavirus (HPV), tumor suppressor loss (p53, MCC, APC, BRCA1), cancer gene mutation (K-ras-2, exons 1 and 2, p53 exons 5 to 8), and oncogene amplification (c-erbB-2/HER-2/neu, int-2). Tissue for genetic evaluation was obtained by microdissection, using 4-micron-thick histology sections of archival, formalin-fixed, paraffin-embedded specimens. Genotyping involved nucleic acid amplification and DNA sequencing with gene-specific oligonucleotides and L1 region consensus primers for common strains of HPV. Point mutation and HPV strain determination were accomplished by DNA sequence analysis. Tumor suppressor gene loss and oncogene amplification were performed by allelic imbalance analysis in informative subjects based on DNA sequence and microsatellite-length polymorphisms. HPV was present in all tumors and consisted of type 16 (n = 5, 42%) and type 18 (n = 7, 58%) strains, which have been closely associated with cervical neoplasia. K-ras-2 and p53 genes did not manifest point mutational damage. There was no evidence of oncogene amplification or tumor suppressor gene loss. The presence of HPV in all 12 tumors supports the role of HPV infection in the molecular pathogenesis of this uncommon neoplasm. The absence of associated oncogene or tumor suppressor gene damage is consistent with indolent biological behavior and the favorable prognosis of this unusual tumor.

Effects of gestational alcohol exposure on the fatty acid composition of umbilical cord serum in humans

This study examined the effects of maternal periconceptional alcohol intake on polyunsaturated fatty acid (PUFA) concentrations in human neonates. The area percentage of each fatty acid in cord blood serum from 12 infants born to control women (who consumed <2 mL absolute ethanol/d) was compared with that of 9 infants born to women whose periconceptional alcohol intake averaged > or = 30mL absolute ethanol/d. Periconceptional alcohol use was associated with a 30% increase in the proportion of docosahexaenoic acid (22:6n-3) in cord blood (3.0% of total lipid in control infants compared with 3.9% in alcohol-exposed infants; P < 0.01). The rise in the proportion of 22:6n-3 was responsible for increases in the ratio of n-3 to n-6 fatty acids and the ratio of long-chain n-3 to n-6 fatty acids (P < 0.055). Examination of the lipid-class fatty acid profile indicated that serum lipid alterations were localized to the cholesterol esters; 22:6n-3 in the cholesterol esters of alcohol-exposed infants increased 54% (P < 0.011) and arachidonic acid increased 55% (P < 0. 005). The relative fatty acyl composition of maternal serum showed a significant increase in 18:0 fatty acids in the alcohol-exposed group (25%, P < 0.005) but there were no changes in the other fatty acids. The increase in the proportion of 22:6n-3 was unexpected but is consistent with the hypothesis that this essential lipid may be conserved selectively. These results imply that the lifelong neurobehavioral and sensory dysfunction in fetal alcohol syndrome and other alcohol-related neurodevelopmental disorders may be due in part to PUFA dysregulation.

FILM (5-fluorouracil, ifosfamide, leucovorin and mitomycin C), an alternative chemotherapy regimen suitable for the treatment of advanced breast cancer in the 'out-patient' setting

FILM, a combination of 5-fluorouracil (5-FU) 750 mg/m(2), ifosfamide 1 g/m(2), leucovorin 200 mg/m(2) and mitomycin C 6 mg/m(2) (alternate cycles), was administered to 24 chemo-naive patients with inoperable disease, locally advanced or metastatic. Up to 6 x 3-weekly cycles of FILM were administered on an out-patient basis. Responses included 8 patients in complete remission (CR) and 12 showing a partial response (PR) (83%). Following analysis of these results, the FILM regimen was introduced as a standard out-patient protocol at the North Middlesex Hospital, United Kingdom. A further 66 patients have been treated in this setting. Retrospective analysis of these data confirm the trial results and allow conclusions regarding tolerability, toxicity, duration of response and survival to be drawn from a total cohort of 90 patients. A total of 524 cycles have been administered. Nineteen cycles (4%) were delayed owing to slow recovery of white blood cells (WBC), but no dose reductions were necessary. Five blood transfusions were required for anaemia. The most frequent non-haematological toxicities included nausea, vomiting and fatigue. Of 80 patients treated for inoperable or locally advanced disease, 56 (70%) remain in remission, and 69 (86%) remain alive after 5 years.

Cold-temperature plastic resin embedding of liver for DNA- and RNA-based genotyping

The standard practice of tissue fixation in 10% formalin followed by embedding in paraffin wax preserves cellular morphology at the expense of availability and quality of DNA and RNA. The negative effect on cellular constituents results from a combination of extensive cross-linking and strand scission of DNA, RNA, and proteins induced by formaldehyde as well as RNA loss secondary to ubiquitous RNase activity and negative effects of high temperature exposure during paraffin melting, microscopic section collection, and tissue adherence to glass slides. An effective strategy to correlate cellular phenotype with molecular genotype involves microdissection of tissue sections based on specific histopathological features followed by genotyping of minute representative samples for specific underlying molecular alterations. Currently, this approach is limited to short-length polymerase chain reaction amplification (<250 bp) of DNA, due to the negative effects of standard tissue fixation and processing. To overcome this obstacle and permit both cellular morphology and nucleic acid content to be preserved to the fullest extent, we instituted a system of cold-temperature plastic resin embedding based on the use of the water-miscible methyl methacrylate polymer known as Immunobed (Polysciences, Warminster, PA). The system is simple, easy to adapt to clinical practice, and cost-effective. Immunobed tissue sections demonstrate a cellular appearance equivalent or even superior to that of standard tissue sections. Moreover, thin sectioning (0.5-1.0 microm thickness) renders ultrastructural evaluation feasible on plastic-embedded blocks. Tissue microdissection is readily performed, yielding high levels of long DNA and RNA for genomic and transcription-based correlative molecular analysis. We recommend the use of Immunobed or similar products for use in molecular anatomical pathology.

The causes of patient dropout from penile self-injection therapy for impotence

PURPOSE

Penile self-injection therapy, a second line treatment for erectile dysfunction, is the most efficacious means of reestablishing functional erections when first line therapies fail and the patient wants to avoid penile prosthesis implantation. Despite high efficacy rates, injection therapy has high dropout rates. To our knowledge studies to date analyzing patient attrition have reviewed small numbers of patients followed for only short periods. We elucidate the main reasons for patient dropout in a large penile self-injection program with long-term followup.

MATERIALS AND METHODS

A questionnaire was mailed to 1,424 patients who completed the office training and home use phases of a penile self-injection program.

RESULTS

The overall attrition rate was 31% of the 720 men who completed the questionnaire, with a mean followup of 38 months. The main reasons for dropout were cost of therapy, patient and partner problems with the concept of penile injection, lack of partner availability and spontaneous improvement in erections. Lack of efficacy of therapy was the primary reason for only 1 of 7 dropouts. Furthermore, adverse effects of penile injections (priapism, penile nodules, pain) appeared to be only minor contributors to dropout.

CONCLUSIONS

To our knowledge this study is the largest published, single center cohort of patients treated with injection and followed for an analysis of dropout rates. Based on study data a reduction in dropout rates may be achieved by keeping the cost of therapy low, and ensuring patient and partner education as well as continued support throughout treatment.

Clinical options for women at high risk for breast cancer

Women at hereditary risk of breast cancer face a difficult clinical decision. Each of the options available to them has unique advantages and disadvantages that are summarized in Table 9. Many components enter a high-risk woman's decision: her objective risk of breast cancer; clinical features, such as the consistency of breast tissue and resultant ease of examination; breast density on mammography; personal characteristics, including her experience with cancer within her family; her role and [table: see text] responsibilities within her own nuclear family; her values and goals; her experiences with the medical system; and her subjective assessment of risk. It is generally believed that women significantly overestimate their risk of breast cancer. Thus, it is vital that a woman at risk have access to a genetic counselor who can provide accurate assessment of her risk. Women should be encouraged to take time to understand their risk level and the advantages and disadvantages of the options before them.

Peroxisome proliferator-activated receptor gamma is induced during differentiation of colon epithelium cells

Peroxisome proliferator-activated receptor gamma (PPARgamma), a fatty acid-activated nuclear receptor, is implicated in adipocyte differentiation and insulin sensitisation. In view of the association of dietary fat intake and bowel disease, the expression of PPARgamma in rodent and human intestine was studied. Expression of PPARgamma mRNA was examined by Northern blot hybridisation, RNase protection, and/or competitive RT-PCR assays, whereas PPARgamma protein levels were evaluated by immunoblotting and immunohistochemistry. PPARgamma mRNA and protein were abundantly expressed in colon relative to the small intestine both in rodents and in man. Interestingly, expression of PPARgamma was primarily localised in the more differentiated epithelial cells in the colon. The level of expression of PPARgamma in colon was similar to the levels seen in adipose tissue. Expression of PPARgamma increased from proximal to distal segments of the colon in man. In Caco-2 and HT-29 human adenocarcinoma cells, PPARgamma expression increased upon differentiation, consistent with PPARgamma being associated with a differentiated epithelial phenotype. High-level expression of PPARgamma was observed in the colon, but not in the small intestine, suggesting a potential role of this nuclear receptor in the colon.

Visual and verbal metaphors among children with typical language and language disorders

Twelve children with language disorders and 12 control subjects were presented with a series of 24 photographic plates from the Metaphoric Triads Test and asked to explain all possible pairings. They also performed a similar task, matched for content, using verbally prepared stimuli. For each trial, one pairing had been designed to make highly probable a metaphoric pairing. Control subjects provided significantly more metaphoric accounts of pairings than children with language disorders, regardless of modality. In addition, photographic plates elicited significantly more metaphoric pairings than verbal preparations. No significant interactions were observed. The findings are discussed from the perspectives of (1) generalized symbolic function and (2) verbal mediation function. The authors call for more research on the role of verbal mediation in metaphoric reasoning.