The Cdx2 homeobox gene has a tumour suppressor function in the distal colon in addition to a homeotic role during gut development

BACKGROUND: During development, the homeobox gene Cdx2 exerts a homeotic function, providing the positional information necessary for correct specification of the midgut endoderm. This is illustrated by the non-neoplastic gastric-type heteroplasias present at birth in the pericaecal region of Cdx2(+/-) mice. Furthermore, intestinal expression of Cdx2 continues throughout life but diminishes in colorectal cancers compared with adjacent normal tissue, suggesting a role in tumorigenesis. Aim: To investigate the consequence of altered Cdx2 expression on colon tumour initiation and/or progression. METHODS: Heterozygous Cdx2(+/-) mice were analysed for spontaneous malignant tumours and for tumour development after treatment with a DNA mutagen, azoxymethane. RESULTS: Cdx2(+/-) mice did not spontaneously develop malignant tumours. After azoxymethane treatment, the gastric-like heteroplasias in the pericaecal region did not evolve into cancer indicating that they are not precancerous lesions. However, azoxymethane treated Cdx2(+/-) mice developed tumours specifically in the distal colon 12 weeks after azoxymethane treatment whereas no tumours were found in wild-type littermates at this stage. Histopathological and molecular analyses indicated that these tumours were invasive adenocarcinomas that recapitulated the malignant sequence observed in the majority of sporadic colorectal cancers in human. In addition, we found that the colonic epithelium was less sensitive to radiation induced apoptosis in Cdx2(+/-) than in wild-type mice. CONCLUSION: This study provides the first experimental evidence that Cdx2 is a tumour suppressor gene involved in cancer progression in the distal colon. This action in adults is functionally and geographically distinct from its homeotic role during gut development.     

Expression of the novel adrenocorticotropin-responsive gene selective Alzheimer's disease indicator-1 in the normal adrenal cortex and in adrenocortical adenomas and carcinomas

Selective Alzheimer's disease indicator-1 (seladin-1) is a novel gene with antiapoptotic activity that is down-regulated in vulnerable brain regions in Alzheimer's disease. This gene encodes 3-beta-hydroxysterol Delta-24-reductase (DHCR24), which converts desmosterol into cholesterol. In the adrenal cortex, increased expression of seladin-1/DHCR24, which appears to be modulated by ACTH, has been recently reported in cortisol-secreting adenomas, compared with the adjacent atrophic tissue. In our study, we measured the expression level of seladin-1/DHCR24 in cortisol- (n = 18) and aldosterone-secreting (n = 16) adrenocortical adenomas, in carcinomas (n = 17), and in normal adrenal glands (n = 8) by quantitative real-time RT-PCR. The amount of seladin-1/DHCR24 mRNA was significantly reduced in carcinomas (total RNA, 2.5 +/- 0.8 pg/ micro g) compared with the other groups (P < 0.01). Western blot analysis confirmed the mRNA results. Similarly, in adrenal malignancies, significantly reduced levels of expression of the ACTH receptor gene were found. In the adrenal cancer cell line H295R and in primary cultures from adrenocortical cells, ACTH (1 nM) and forskolin (10 micro M) effectively increased seladin-1/DHCR24 expression, confirming that seladin-1/DHCR24 is modulated by the ACTH/cAMP-driven pathway. In summary, this is the first demonstration that seladin-1/DHCR24 expression is reduced in adrenal cancer, suggesting that it might be viewed as a new potential marker of adrenal malignancies.     

Chemotherapy for mobilisation of Ph-negative progenitor cells from patients with CML: impact of different mobilisation regimens

Mobilised peripheral blood stem cells are widely used for autografting in patients with chronic myeloid leukaemia (CML) and it is generally thought that a high proportion of Ph-negative progenitor cells in the graft is desirable. We report here the results of 91 stem cell mobilisations performed with various chemotherapy regimens followed by G-CSF. We show that mobilisation of Ph-negative cells is possible after diagnosis as well as in advanced stages of the disease. The yield of Ph-negative cells is highly dependent on the chemotherapy regimen: while the combination of idarubicin and cytarabin for 3-5 days (IC3-5) mobilised Ph-negative cells in most patients, high-dose cyclophosphamide was ineffective. Mobilisation of Ph-negative progenitor cells after IC3 was at least as effective as after IC5; however, less apheresis sessions were required, and toxicity was much reduced after IC3. Compared to historical controls, IC was equally effective as the widely used ICE/miniICE (idarubicin, cytarabin, etoposide) protocol. No correlation was found between graft quality and the cytogenetic response to subsequent treatment with interferon-alpha. We conclude that IC3 is an effective and well-tolerated regimen for mobilising Ph-negative cells that compares well with more aggressive approaches such as IC5 and ICE/miniICE.     

Brain monoglyceride lipase participating in endocannabinoid inactivation

The endogenous cannabinoids (endocannabinoids) are lipid molecules that may mediate retrograde signaling at central synapses and other forms of short-range neuronal communication. The monoglyceride 2-arachidonoylglycerol (2-AG) meets several criteria of an endocannabinoid substance: (i) it activates cannabinoid receptors; (ii) it is produced by neurons in an activity-dependent manner; and (iii) it is rapidly eliminated. 2-AG inactivation is only partially understood, but it may occur by transport into cells and enzymatic hydrolysis. Here we tested the hypothesis that monoglyceride lipase (MGL), a serine hydrolase that converts monoglycerides to fatty acid and glycerol, participates in 2-AG inactivation. We cloned MGL by homology from a rat brain cDNA library. Its cDNA sequence encoded for a 303-aa protein with a calculated molecular weight of 33,367 daltons. Northern blot and in situ hybridization analyses revealed that MGL mRNA is heterogeneously expressed in the rat brain, with highest levels in regions where CB(1) cannabinoid receptors are also present (hippocampus, cortex, anterior thalamus, and cerebellum). Immunohistochemical studies in the hippocampus showed that MGL distribution has striking laminar specificity, suggesting a presynaptic localization of the enzyme. Adenovirus-mediated transfer of MGL cDNA into rat cortical neurons increased MGL expression and attenuated N-methyl-D-aspartate/carbachol-induced 2-AG accumulation in these cells. No such effect was observed on the accumulation of anandamide, another endocannabinoid lipid. The results suggest that hydrolysis by means of MGL is a primary mechanism for 2-AG inactivation in intact neurons.     

Detection of bulimia in a primary care setting

Objective: To develop a screening tool for the identification of bulimia in ambulatory practice. Design: Administration of a 112-item questionnaire about eating and weight-control practices to women with known bulimia and to healthy control patients. Questions were compared with DSM-III-R criteria of bulimia as a “gold standard.” Setting: Self-help group for eating disorders and hospital-based primary care practice. Subjects: Thirty of 42 women with known bulimia met DSM-III-R criteria for current bulimia, and 124 of 130 control patients met the criterion of no history of an eating disorder. Main results: Thirteen individual questions discriminated between bulimic subjects and control subjects with a sensitivity and specificity of >75%. When these questions were entered into a stepwise logistic model, two questions were independently significant. A “no” response to the question “Are you satisfied with your eating patterns?” or a “yes” response to “Do you ever eat in secret?” had a sensitivity of 1.00 and a specificity of 0.90 for bulimia. The positive predictive value, based on a 5% prevalence, was 0.36. Conclusions: A set of two questions may be as effective as a more extensive questionnaire in identifying women with eating disorders, and could be easily incorporated into the routine medical history obtained from all women.     

Electrophysiological Interactions of Ethanol with GABAergic Mechanisms in the Rat Cerebellum in Vivo

Biochemical studies indicate that ethanol (EtOH) will facilitate the activation of the GABA_A/CI^– channel, and behavioral studies demonstrate that EtOH-induced sedative and incoordinating effects can be potentiated by GABA mimetics and blocked by GABA antagonists. It has been difficult, however, to demonstrate an EtOH-induced potentiation of the depressant electrophysiological effects of locally applied GABA in mammalian brain in vivo. Similarly, in this study, local EtOH applications only infrequently caused potentiations of the depressant effects of microiontophoretically applied GABA on cerebellar Purkinje neurons, and this interaction was modest when present. The predominant interaction of locally applied EtOH was an antagonism of GABA-induced depressions of neuronal activity. However, the GABA_A receptor antagonist bicuculline reversibly and apparently competitively blocked the depressant effects of locally applied EtOH on single cerebellar Purkinje neurons. Our data suggest that EtOH potentiation of GABA responses alone is insufficient to account for EtOH-induced depressions of cerebellar Purkinje neurons. However, these data clearly imply that activation of a GABA_A receptor is required for the expression of EtOH-induced depressions of neuronal activity in this brain area. It is less clear how lower, nondepressant doses of EtOH interact with GABA mechanisms. We hypothesize that either the GABA_A receptor mechanism must be sensitized to the potentiative effects of EtOH through the influences of neuromodulatory and/or hormonal regulation, or that EtOH interacts directly with these regulatory processes.     

Loss of Cholinergic Muscarinic Receptors in the Frontal Cortex of Alcohol Abusers

Alcohol abuse causes impairment of cognitive function ranging from mild forms to end-stage dementia. Alcohol-related dementia accounts for nearly 20% of all admissions to state mental hospitals and may result from head trauma, thiamine deficiency, Alzheimer's, and other brain diseases that can be diagnosed conclusively only at autopsy. However, we postulate that after all these conditions have been excluded, an "alcohol encephalopathy" remains. This is characterized by impaired synaptic function, which underlies the continuum of impaired intellectual function. We found in 79 histologically normal brains of a nondemented general hospital population a 40% decrease in the density of cholinergic muscarinic receptors in the frontal cortex of alcoholics when compared with matched controls of the same age. Only alcohol abuse and not aging, postmortem changes, medications, clinical (including liver) diseases, or differences in causes of death could account for this loss.     

Myeloablative intensified conditioning regimen with in vivo T-cell depletion (ATG) followed by allografting in patients with advanced multiple myeloma. A phase I/II study of the German Study-group Multiple Myeloma (DSMM)

We investigated toxicity and efficacy of in vivo T-cell depletion with anti-thymocyte globulin (ATG) as part of an intensified myeloablative conditioning regimen followed by allogeneic stem cell transplantation in patients with advanced multiple myeloma. The conditioning regimen consisted of modified total body irradiation, busulfan and cyclophosphamide (n=15) or in the case of prior dose-limiting radiotherapy of busulfan and cyclophosphamide (n=3). The median age was 44 years (range, 29-53) and the median time from diagnosis to transplant was 12 months (range, 6-144). Grade II-IV acute graft-versus-host disease (GvHD) occurred in six patients (35%). Severe grade III/IV GvHD developed in one patient (6%). Three patients died of therapy-related causes (17%). A complete remission (CR) with negative immunofixation after allogeneic transplantation was seen in eight of the evaluable patients (53%). After a median follow-up of 41 months (range, 8-84), the estimated overall survival at 6 years for all patients is 77% (CI 95%: 58-96%). The estimated progression-free survival at 6 years for all patients is 31% (CI 95%: 2-59%) and 46% (CI 95%: 9-83%) for patients with CR. In vivo T-cell depletion with ATG resulted in a low rate of severe GvHD with low treatment-related mortality, and a substantial number of long-term survivors.     

Gender differences in the treatment of cerebrovascular disease

OBJECTIVE: Previous studies have shown that women receive fewer invasive procedures for the treatment of coronary artery disease than men, but gender differences in cerebrovascular disease have not been well studied. Our objective was to explore differences in the treatment of stroke between men and women. DESIGN: Secondary database analyses. STUDY PARTICIPANTS: We examined the use of carotid endarterectomy in a nationally representative sample of Medicare enrollees aged 65 to 84, hospitalized for a principal diagnosis of stroke in 1992, the "all strokes group". We also studied a subgroup of patients, the "carotid disease subgroup", admitted with a principal diagnosis of precerebral arterial occlusion and stenosis or transient cerebral ischemia. MEASUREMENTS: We determined rates of carotid endarterectomy for the all strokes group within gender and age groups and calculated corresponding female-to-male relative risks (RR) and 95% confidence intervals (CI). We also performed similar analyses for the carotid disease subgroup. We then used logistic regression to estimate the relative risk of use of carotid endarterectomy for women, controlling for age and comorbidity. RESULTS: The all-strokes group consisted of 3,356 women and 2,927 men, of whom 1,009 women and 990 men were in the carotid disease subgroup. The overall age-adjusted female-to-male relative risk of undergoing carotid endarterectomy for those aged 65 to 84 was 0.69 (95% CI, 0.64-0.74) in the all strokes group and 0.77 (95% CI, 0.72-0.82) in the carotid disease subgroup. In both analyses, the RR became more pronounced with increasing age. In the all strokes group, for example, the RR was 0.80 (0.70-0.92) for those aged 65 to 69 and 0.39 (0.32-0.48) for those aged 80 to 84. The RR for the all strokes group remained similar in magnitude even after controlling for comorbidity (RR, 0.63 and 95% CI, 0.59-0.70). CONCLUSION: We conclude that women hospitalized for strokes undergo fewer carotid endarterectomies than men. Further studies are needed to examine the reasons for and implications of this gender difference.     

Simultaneous voxel‐wise analysis of brain and spinal cord morphometry and microstructure within the SPM framework

To validate a simultaneous analysis tool for the brain and cervical cord embedded in the statistical parametric mapping (SPM) framework, we compared trauma‐induced macro‐ and microstructural changes in spinal cord injury (SCI) patients to controls. The findings were compared with results obtained from existing processing tools that assess the brain and spinal cord separately. A probabilistic brain‐spinal cord template (BSC) was generated using a generative semi‐supervised modelling approach. The template was incorporated into the pre‐processing pipeline of voxel‐based morphometry and voxel‐based quantification analyses in SPM. This approach was validated on T1‐weighted scans and multiparameter maps, by assessing trauma‐induced changes in SCI patients relative to controls and comparing the findings with the outcome from existing analytical tools. Consistency of the MRI measures was assessed using intraclass correlation coefficients (ICC). The SPM approach using the BSC template revealed trauma‐induced changes across the sensorimotor system in the cord and brain in SCI patients. These changes were confirmed with established approaches covering brain or cord, separately. The ICC in the brain was high within regions of interest, such as the sensorimotor cortices, corticospinal tracts and thalamus. The simultaneous voxel‐wise analysis of brain and cervical spinal cord was performed in a unique SPM‐based framework incorporating pre‐processing and statistical analysis in the same environment. Validation based on a SCI cohort demonstrated that the new processing approach based on the brain and cord is comparable to available processing tools, while offering the advantage of performing the analysis simultaneously across the neuraxis.