Effect of home-based light treatment on persons with dementia and their caregivers.

Sleep disorders are problematic for persons with dementia and their family caregivers. This randomized controlled trial with crossover evaluated the effects of an innovative blue-white light therapy on 17 pairs of home-dwelling persons with dementia and their caregivers. Subjects with dementia received blue-white light and control ('red-yellow' light) for six weeks separated by a four-week washout. Neither actigraphic nor most self-reported sleep measures significantly differed for subjects with dementia. For caregivers, both sleep and role strain improved. No evidence of retinal light toxicity was observed. Six weeks of modest doses of blue-white light appear to improve sleep in caregivers but not in persons with dementia. Greater or prolonged circadian stimulation may be needed to determine if light is an effective treatment for persons with dementia.

Exposure of neonatal rats to anti-androgens induces penile mal-developments and infertility comparable to those induced by oestrogens.

We previously reported that oestrogen exposure in neonatal rats induced permanent infertility and malformed penis characterized by fat accumulation, which replaced most of the smooth muscle cells and cavernous spaces in the body of the penis, structures essential for erection. The objective of this study was to determine if reduced androgen production/action in the neonatal period, in the absence of exogenous oestrogen exposure, induces penile deformities similar to those caused by oestrogen. Male rats were treated from postnatal days 1-6 with GnRH antagonist antide (A, 10 mg/kg) or androgen receptor (AR) antagonist flutamide (F, 50 mg/kg) or F + A, with or without AR agonist dihydrotestosterone (DHT, 20 mg/kg). For comparison, pups received diethylstilbestrol (DES, 0.1 mg/kg), with or without DHT. Tissues were collected at ages 7 and 12 days and at adulthood. Flutamide alone decreased penile length and weight significantly (p < 0.05), but it caused neither fat accumulation, nor affected fertility (80% vs. 87% in controls). Antide alone reduced penile length and weight significantly, and induced fat accumulation in 4/11 rats and infertility in 13/14 rats. Conversely, all 11 F + A-treated rats, similar to all nine DES-treated rats, had fat accumulation and loss of smooth muscle cells and cavernous spaces in the body of the penis and were infertile. In addition, reductions in penile length and weight were higher than in rats treated with F or A alone. DHT co-administration mitigated penile deformities in the DES group, but did not in the F + A group. Testicular testosterone was reduced by 70-95% at 7 or 12 days of age in all treated groups, except in the F group, which had threefold higher testosterone than controls. Collectively, data unequivocally show that reduced androgen production/action in the neonatal period, in the absence of oestrogen exposure, induces permanent infertility and malformed penis similar to that caused by oestrogen.

Estrogen-induced developmental disorders of the rat penis involve both estrogen receptor (ESR)- and androgen receptor (AR)-mediated pathways.

This study tested the hypothesis that the estrogen receptor (ESR) pathway, androgen receptor (AR) pathway, or both mediate estrogen-induced developmental penile disorders. Rat pups received diethylstilbestrol (DES), with or without the ESR antagonist ICI 182,780 (ICI) or the AR agonist dihydrotestosterone (DHT) or testosterone (T), from Postnatal Days 1 to 6. Testicular T concentration, penile morphology and morphometry, and/or fertility was determined at age 7, 28, or 150 days. DES treatment alone caused 90% reduction in the neonatal intratesticular T surge; this reduction was prevented by ICI coadministration, but not by DHT or T coadministration. Unlike the T surge, coadministration of ICI and coadministration of DHT or T mitigated penile deformities and loss of fertility. Generally, ICI, DHT, or T treatment alone did not alter penile morphology; however, fertility was 20% that of controls in ICI-treated rats vs. 70%-90% in DHT- or T-treated rats. The lower fertility in the rats treated with ICI alone could be due to altered sexual behavior, as these males did not deposit vaginal plugs. In conclusion, observations that both an ESR antagonist and AR agonists prevent penile deformities and infertility suggest that both pathways are involved in estrogen-induced penile disorders. Observations that coadministration of ICI, but not DHT or T, prevents the DES-induced reduction in the neonatal T surge suggest that, although ICI exerts its mitigating effect both at the level of Leydig cells and penile stromal cells, DHT and T do so only at the level of stromal cells.

Family Experiences with the Diagnosis of Autism Spectrum Disorder: System Barriers and Facilitators of Efficient Diagnosis.

This paper examines family experiences with the efficiency of ASD diagnosis. Children were age 8 or younger with ASD (n = 450). Outcomes were delay from first parent concern to diagnosis, shifting diagnoses, and being told child did not have ASD. Predictors were screening, travel distance, and problems finding providers. Logit models were used to examine associations. Screening was associated with reduced delay in diagnosis; problems finding providers were associated with greater delay. Screening, travel distance, and delay in diagnosis were associated with shifting diagnoses and being told child did not have ASD. Physician and parent training in communication and addressing mental health professional shortages and maldistribution may improve the diagnosis experiences of families of children with ASD.

Lumbosacral spinal cord epidural stimulation improves voiding function after human spinal cord injury.

Deficits in urologic function after spinal cord injury (SCI) manifest both as a failure to store and empty, greatly impacting daily life. While current management strategies are necessary for urological maintenance, they oftentimes are associated with life-long side effects. Our objective was to investigate the efficacy of spinal cord epidural stimulation (scES) as a promising therapy to improve bladder control after SCI. A bladder mapping study was undertaken for sixteen sessions over the course of four months in an individual with chronic, motor complete SCI. Varying combinations of stimulating cathode electrodes were initially tested during filling cystometry resulting in the identification of an effective configuration for reflexive bladder emptying at the caudal end of the electrode array. Subsequent systematic testing of different frequencies at a fixed stimulus intensity and pulse width yielded lowest post-void residual volumes at 30 Hz. These stimulation parameters were then tested in four additional research participants and found to also improve reflexive voiding efficiency. Taken together with SCI studies on step, stand, voluntary motor control and cardiovascular regulation, these findings further corroborate that scES has an all-encompassing potential to increase the central state of excitability, allowing for the control of multiple body functions, including the urological system.

Host cyclooxygenase-2 modulates carcinoma growth.

Cyclooxygenase-2 (COX-2; Ptgs2) acts as a tumor promoter in rodent models for colorectal cancer, but its precise role in carcinogenesis remains unclear. We evaluated the contribution of host-derived COX-1 and COX-2 in tumor growth using both genetic and pharmacological approaches. Lewis lung carcinoma (LLC) cells grow rapidly as solid tumors when implanted in C57BL/6 mice. We found that tumor growth was markedly attenuated in COX-2(-/-), but not COX-1(-/-) or wild-type mice. Treatment of wild-type C57BL/6 mice bearing LLC tumors with a selective COX-2 inhibitor also reduced tumor growth. A decrease in vascular density was observed in tumors grown in COX-2(-/-) mice when compared with those in wild-type mice. Because COX-2 is expressed in stromal fibroblasts of human and rodent colorectal carcinomas, we evaluated COX-2(-/-) mouse fibroblasts and found a 94% reduction in their ability to produce the proangiogenic factor, VEGF. Additionally, treatment of wild-type mouse fibroblasts with a selective COX-2 inhibitor reduced VEGF production by 92%.

A nucleotide substitution in the promoter of human angiotensinogen is associated with essential hypertension and affects basal transcription in vitro.

In earlier studies, we provided statistical evidence that individual differences in the angiotensinogen gene, the precursor of the vasoactive hormone angiotensin II, constitute inherited predispositions to essential hypertension in humans. We have now identified a common variant in the proximal promoter, the presence of an adenine, instead of a guanine, 6 bp upstream from the initiation site of transcription, in significant association with the disorder. Tests of promoter activity and DNA binding studies with nuclear proteins suggest that this nucleotide substitution affects the basal transcription rate of the gene. These observations provide some biological insight about the possible mechanism of a genetic predisposition to essential hypertension; they may also have important evolutionary implications.

Interleukin-22 drives nitric oxide-dependent DNA damage and dysplasia in a murine model of colitis-associated cancer.

The risk of colon cancer is increased in patients with Crohn's disease and ulcerative colitis. Inflammation-induced DNA damage could be an important link between inflammation and cancer, although the pathways that link inflammation and DNA damage are incompletely defined. RAG2-deficient mice infected with Helicobacter hepaticus (Hh) develop colitis that progresses to lower bowel cancer. This process depends on nitric oxide (NO), a molecule with known mutagenic potential. We have previously hypothesized that production of NO by macrophages could be essential for Hh-driven carcinogenesis, however, whether Hh infection induces DNA damage in this model and whether this depends on NO has not been determined. Here we demonstrate that Hh infection of RAG2-deficient mice rapidly induces expression of iNOS and the development of DNA double-stranded breaks (DSBs) specifically in proliferating crypt epithelial cells. Generation of DSBs depended on iNOS activity, and further, induction of iNOS, the generation of DSBs, and the subsequent development of dysplasia were inhibited by depletion of the Hh-induced cytokine IL-22. These results demonstrate a strong association between Hh-induced DNA damage and the development of dysplasia, and further suggest that IL-22-dependent induction of iNOS within crypt epithelial cells rather than macrophages is a driving force in this process.

Heat shock cognate 70 mutations in sporadic breast carcinoma.

Heat Shock Cognate 70 (HSC70) is a constitutively expressed molecular chaperone, functions of which regulate the structure, subcellular localization, and turnover of cell proteins. It is also a component of the centrosome facilitating rearrangements during mitotic/meiotic spindle formation and cytoplasmic microtubule organization. We localized HSC70 to 11q23.3, a region deleted in 40% of sporadic breast and other cancers. Sequencing demonstrated mutation in the NH2-terminal ATPase domain of HSC70 in 2 of 15 sporadic breast carcinomas examined. In both cases, mutation was coincident with allelic imbalance, suggesting that HSC70 is a target of somatic mutation and deletion in a fraction of breast carcinomas.

Celecoxib prevents tumor growth in vivo without toxicity to normal gut: lack of correlation between in vitro and in vivo models.

Nonsteroidal anti-inflammatory drugs have potential for use in the prevention and/or treatment of colorectal cancer. We have studied the cytotoxic effect of a specific COX-2 inhibitor, celecoxib, against LLC, HCA-7, and HCT-15 cells grown in cell culture and have compared these results with its effect on HCA-7 cells grown as xenografts in nude mice. "High-dose" celecoxib (>20 microM) reduced the viability of all three cell lines in vitro as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometric analysis demonstrated that this loss of viability was attributable to the induction of apoptosis. Significantly, concentrations of the drug <10 microM had no effect on cell viability in vitro. The cytotoxic effects of high-dose celecoxib were independent of COX-2 inhibition because similar effects were observed in cox-2 (+/+), cox-2 (+/-) and cox-2 (-/-) fibroblasts. A plasma concentration of 2.3+/-0.7 microM was achieved when celecoxib (1250 mg/kg of chow) was fed to animals ad libitum. Despite a lack of toxicity at 2-3 microM celecoxib in vitro, there was attenuation of HCA-7 xenograft growth in vivo. Celecoxib had no effect on apoptosis, cell division, or the epithelial architecture of the normal gut in treated mice. These results support the need for additional clinical evaluation of celecoxib for treatment and/or prevention of colorectal cancer in humans.

Decreased transforming growth factor beta type II receptor expression in intestinal adenomas from Min/+ mice is associated with increased cyclin D1 and cyclin-dependent kinase 4 expression.

Tumor cells often become resistant to the growth-inhibitory effects of transforming growth factor beta (TGF-beta). Recent studies have identified TGF-beta type II receptor (RII) mutations in a subset of cancers, including colon cancer. To evaluate the expression of TGF-beta RII in premalignant intestinal adenomas and the relationship with cell cycle regulation, we investigated the expression of TGF-beta RII, cyclin D1, and cyclin-dependent kinase 4 (Cdk4) in Min/+ mouse intestinal adenomas. Immunohistochemistry indicated that TGF-beta RII cytoplasmic immunoreactivity was undetectable in the proliferative crypt zones of the normal small intestinal and normal colonic epithelium but was abundant toward the villus tips of the normal small intestine and the lumenal third of the colonic glands. As was observed in the proliferating crypt zones, TGF-beta RII immunoreactivity was dramatically decreased or undetectable in all adenomas examined in comparison to the abundant levels in adjacent normal differentiated intestinal epithelium. TGF-beta RII mRNA was also reduced in the adenomas in comparison to normal mucosa as determined by reverse transcription-PCR. In an inverse distribution to TGF-beta RII, Cdk4 nuclear immunoreactivity was restricted to the crypt regions of the small and large intestine, whereas cyclin D1 immunoreactivity was uniformly absent in normal intestinal epithelium. For both cyclin D1 and Cdk4, protein and mRNA levels were increased in intestinal adenomas but not in normal intestinal epithelium as determined by immunohistochemistry, in situ hybridization, and reverse transcription-PCR. In summary, the lack of TGF-beta RII expression was associated with increased cyclin D1 and Cdk4 expression in Min/+ mouse intestinal adenomas. We hypothesize that the former may enable tumor cells to escape from the normal growth-constraining influence of TGF-beta, whereas the latter promotes inappropriate cell proliferation and adenoma progression.

Myeloid translocation genes differentially regulate colorectal cancer programs.

Myeloid translocation genes (MTGs), originally identified as chromosomal translocations in acute myelogenous leukemia, are transcriptional corepressors that regulate hematopoietic stem cell programs. Analysis of The Cancer Genome Atlas (TCGA) database revealed that MTGs were mutated in epithelial malignancy and suggested that loss of function might promote tumorigenesis. Genetic deletion of MTGR1 and MTG16 in the mouse has revealed unexpected and unique roles within the intestinal epithelium. Mtgr1-/- mice have progressive depletion of all intestinal secretory cells, and Mtg16-/- mice have a decrease in goblet cells. Furthermore, both Mtgr1-/- and Mtg16-/- mice have increased intestinal epithelial cell proliferation. We thus hypothesized that loss of MTGR1 or MTG16 would modify Apc1638/+-dependent intestinal tumorigenesis. Mtgr1-/- mice, but not Mtg16-/- mice, had a 10-fold increase in tumor multiplicity. This was associated with more advanced dysplasia, including progression to invasive adenocarcinoma, and augmented intratumoral proliferation. Analysis of chromatin immunoprecipitation sequencing data sets for MTGR1 and MTG16 targets indicated that MTGR1 can regulate Wnt and Notch signaling. In support of this, immunohistochemistry and gene expression analysis revealed that both Wnt and Notch signaling pathways were hyperactive in Mtgr1-/- tumors. Furthermore, in human colorectal cancer (CRC) samples MTGR1 was downregulated at both the transcript and protein level. Overall our data indicates that MTGR1 has a context-dependent effect on intestinal tumorigenesis.

The role of cyclooxygenases in inflammation, cancer, and development.

The cyclooxygenase (COX) enzymes catalyze a key step in the conversion of arachidonate to PGH2, the immediate substrate for a series of cell specific prostaglandin and thromboxane synthases. Prostaglandins play critical roles in numerous biologic processes, including the regulation of immune function, kidney development, reproductive biology, and gastrointestinal integrity. There are two COX isoforms, which differ mainly in their pattern of expression. COX-1 is expressed in most tissues, whereas COX-2 usually is absent, but is induced by numerous physiologic stimuli. Surprisingly, disruption of Cox1 (Ptgs1) in the mouse did not result in gastrointestinal abnormalities. cox-2 (Ptgs2) null mice show reproductive anomalies and defects in kidney development. Epidemiologic, animal, and human data indicate that NSAIDs, inhibitors of cyclooxygenase, are chemopreventive for colon cancer. COX-2 is overexpressed in 50% of benign polyps and 80-85% of adenocarcinomas. Offspring from cox-2 null by Apcdelta716 matings exhibit an 86% reduction in polyp number when compared to offspring from control animals, thus providing genetic evidence that COX-2 contributes to tumor formation or growth. The in vivo mechanism by which COX-2 affects tumor growth has not been determined. It is possible that both tumor and stromally derived COX-2 could influence tumor angiogenesis and/ or immune function.

Estrogen-induced abnormal accumulation of fat cells in the rat penis and associated loss of fertility depends upon estrogen exposure during critical period of penile development.

We previously reported that diethylstilbestrol (DES) or estradiol valerate (EV) exposure at a dose of 0.10-0.12 mg/kg, or higher, per day, on alternate days, from postnatal days 2-12, resulted in abnormal penis development and infertility (H. O. Goyal et al., 2005, J. Androl. 26, 32-43). The objective of this study was to identify a critical developmental period(s) during which EV exposure results in the observed penile abnormalities. Male pups received EV at a dose of 0.10-0.12 mg/kg on postnatal day(s) 1, 1-3, 4-6, 1-6, 7-12, 13-18, 19-24, or 25-30. Fertility was tested at 102-115 days of age and tissues were examined at 117-137 days. Both penile morphology and fertility were unaltered in rats treated with EV after 12 days of age. Conversely, except in rats treated on postnatal day 1 only, none of the males treated prior to 12 days of age sired pups, and all had abnormal penises, including varying degrees of abnormal accumulation of fat cells and loss of cavernous spaces and smooth muscle cells in the corpora cavernosa penis, which were maximal in the 1-6-day group. Also, the preputial sheath was partially released or its release was delayed, and the weight of the bulbospongiosus muscle was significantly reduced. Plasma testosterone (T) in the 1-6- and 4-6-day groups and intratesticular T in the 4-6-day group were significantly lower. The testosterone surge, characteristic of controls in the first week of life, was suppressed in the 1-3-day group. Estrogen receptor alpha mRNA expression was enhanced in the body of the penis in the 1-3-day group, but not in the 13-18-day group. Hence, EV exposure prior to 12 days of age (as short as 1-3 days postnatal), but not after 12 days of age, results in long-term abnormal penile morphology, characterized by abnormal accumulation of fat cells in the corpora cavernosa penis and, consequently, loss of fertility.

Functional disability and health care expenditures for older persons.

BACKGROUND: The rapidly expanding proportion of the US population 65 years and older is anticipated to have a profound effect on health care expenditures. Whether the changing health status of older Americans will modulate this effect is not well understood. This study sought to determine the relationship between functional status and government-reimbursed health care services in older persons. METHODS: Longitudinal cohort study of a representative sample of community-dwelling persons 72 years or older. Clinical data were linked with data on 2-year expenditures for Medicare-reimbursed hospital, outpatient, and home care services and Medicare- and Medicaid-reimbursed nursing home services. Per capita expenditures associated with different functional status transitions were calculated, as were excess expenditures associated with functional disability adjusted for demographic, health, and psychosocial variables. RESULTS: The 19.6% of older persons who had stable functional dependence or who declined to dependence accounted for almost half (46.3%) of total expenditures. Persons in these groups had an excess of approximately $10 000 in expenditures in 2 years compared with those who remained independent. The 9.6% of patients who were dependent at baseline accounted for more than 40.0% of home health and nursing home expenditures; the 10.0% who declined accounted for more than 20.0% of hospital, outpatient, and nursing home expenditures. CONCLUSIONS: Functional dependence places a large burden on government-funded health care services. Whereas functional decline places this burden on short- and long-term care services, stable functional dependence places the burden predominantly on long-term care services. Declining rates of functional disability and interventions to prevent disability hold promise for ameliorating this burden.

Depression and risk of coronary heart disease in elderly men and women: New Haven EPESE, 1982-1991. Established Populations for the Epidemiologic Studies of the Elderly.

BACKGROUND: Results of several recent studies suggest that depression is predictive of incident coronary disease. However, few studies have examined this relationship in the elderly, the age at which most coronary heart disease (CHD) becomes clinically manifest. METHODS AND RESULTS: Data are from the New Haven, Conn, cohort (N = 2812) of the Established Populations for the Epidemiologic Studies of the Elderly project. Baseline information on depressive symptoms and CHD risk factors was collected during an in-person interview in 1982. Nonfatal myocardial infarctions were identified through monitoring of admissions to local hospitals and were validated by medical chart review. Cause of death was obtained from death certificates for all deceased participants. Outcomes were defined as CHD deaths (n = 255) and total incident CHD events (n = 391) between January 1, 1982, and December 31, 1991. There was no association between depressive symptoms and CHD outcomes in men. Among women, depressive symptoms were associated with an age-adjusted relative risk of 1.03 (per unit increase on the symptom scale) for CHD mortality (P=.001) and total CHD incidence (P=.002). These associations were largely unaffected by adjustment for established CHD risk factors but were reduced to nonsignificant levels after additional adjustment for impaired physical function. Additional analysis showed a significant association for depressive symptoms among women who had no physical function impairments or who survived at least 3 years without an event. CONCLUSION: Depressive symptoms may not be independent risk factors for CHD outcomes in elderly populations in general but may increase risk among relatively healthy older women.

Genomic plasticity of the Lucké renal carcinoma: a review.

The differentiation potential of the Lucké renal carcinoma of the northern leopard frog, Rana pipiens, can be characterized by the nuclear transplantation procedure. Transplantation of tumor nuclei into activated and enucleated ova results, in the best of cases, in swimming larvae which fail to feed. The larvae die in about 10 to 14 days. Rescue of tumor nuclear transplantation tadpole tissue, destined to die, has been accomplished by allografting fragments of that tissue to normal hosts. The allografts persist and differentiate a diversity of tissues which cannot be distinguished by histological analysis from allografted normal control tissue. Allografts are an imperfect mode of assay for histological competence because of the immune response of the host. Lymphocytes and eosinophils invade the grafts in about 40 days. The host immune response occurs in both experimental and control allografts. Consequently, we believe that added histogenetic potential exists in the genome of the Lucké renal carcinoma. We propose that unexpressed differentiative potential of the grafted tissue can be extracted by abrogation of the immune response of the host. A herpesvirus is the etiological agent of the Lucké renal carcinoma. We currently seek to detect viral DNA in tissue derived from tumor nuclear transplant embryos. The presence of the viral genetic material in normal mitotic progeny of Lucké tumor cells, if demonstrated, raises the question of the long-term stability of differentiated cells derived from a virus tumor. Alternatively, absence of viral DNA in the tumor nuclear transplant tissue would suggest that normal differentiation ensues after elimination of the oncogenic DNA from that tissue. Loss of viral DNA may prognosticate stable differentiation.

Sulindac sulfide, but not sulindac sulfone, inhibits colorectal cancer growth.

Sulindac sulfide, a metabolite of the nonsteroidal antiinflammatory drug (NSAID) sulindac sulfoxide, is effective at reducing tumor burden in both familial adenomatous polyposis patients and in animals with colorectal cancer. Another sulindac sulfoxide metabolite, sulindac sulfone, has been reported to have antitumor properties without inhibiting cyclooxygenase activity. Here we report the effect of sulindac sulfone treatment on the growth of colorectal carcinoma cells. We observed that sulindac sulfide or sulfone treatment of HCA-7 cells led to inhibition of prostaglandin E2 production. Both sulindac sulfide and sulfone inhibited HCA-7 and HCT-116 cell growth in vitro. Sulindac sulfone had no effect on the growth of either HCA-7 or HCT-116 xenografts, whereas the sulfide derivative inhibited HCA-7 growth in vivo. Both sulindac sulfide and sulfone inhibited colon carcinoma cell growth and prostaglandin production in vitro, but sulindac sulfone had no effect on the growth of colon cancer cell xenografts in nude mice.

A cyclooxygenase-2 inhibitor (SC-58125) blocks growth of established human colon cancer xenografts.

Selective COX-2 inhibitors reduce adenoma formation and cancer progression in rodent models of colorectal cancer. To assess the therapeutic activity of selective COX-2 inhibitors, we tested the effect of SC-58125 treatment on the growth of human colon carcinoma cells in nude mice. Delaying treatment by 2, 4, or 7 weeks following implantation of the carcinoma cells resulted in a significant inhibition of tumor growth. Furthermore, short-term (48 hours) treatment with SC-58125 was sufficient to attenuate tumor growth for up to 15 days. SC-58125 treatment did not alter the rate at which cells underwent apoptosis, but did result in a delayed progression through the cell cycle at the G(2)/M transition. Accordingly, p34(cdc2) protein levels and activity were decreased following SC-58125 treatment. We conclude that SC-58125 primarily exerts a cytostatic effect in vivo, which is likely to be mediated through inhibition of progression through the G(2)/M phase of the cell cycle.

The expression of epidermal growth factor and transforming growth factor-alpha mRNA in the small intestine of suckling rats: organ culture study.

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are associated with regulation of various gastrointestinal functions. In order to better understand their role in developing small intestine EGF, TGF-alpha and EGF-R steady-state mRNA levels and transcript stability were determined. Reverse transcription (RT) competitive-polymerase chain reaction (PCR) revealed that intestinal TGF-alpha mRNA levels were 10-fold higher in comparison with EGF mRNA. The primary intestinal culture technique was used to evaluate mRNA stability. The stability of TGF-alpha mRNA was remarkably lower than the stability of EGF mRNA. High levels of TGF-alpha mRNA accompanied by high degradation rate of this mRNA suggested a rapid turnover of intestinal TGF-alpha mRNA.