Adaptive upregulation of gastric and hypothalamic ghrelin receptors and increased plasma ghrelin in a model of cancer chemotherapy-induced dyspepsia.

Chemotherapy treatment can lead to delayed gastric emptying, early satiety, anorexia, nausea and vomiting, described collectively as the cancer-associated dyspepsia syndrome (CADS). Administration of ghrelin (GHRL), an endogenous orexigenic peptide known to stimulate gastric motility, has been shown to reduce the symptoms of CADS induced in relevant animal models with the potent chemotherapeutic agent, cisplatin. We examined the effects in the rat of cisplatin (6 mg/kg i.p.) treatment on the expression of GHRL and ghrelin receptor (GHSR) mRNAs in the hypothalamus and the stomach at a time-point (2 days) when the effects of cisplatin are pronounced. In addition, plasma levels of GHRL (acylated and total including des-acyl GHRL) were measured and the effect on these levels of treatment with the synthetic glucocorticoid dexamethasone (2 mg/kg s.c. bd.) was investigated. Cisplatin increased GHSR mRNA expression in the stomach (67%) and hypothalamus (52%) but not GHRL mRNA expression and increased the percentage of acylated GHRL (7.03+/-1.35% vs. 11.38+/-2.40%) in the plasma. Dexamethasone reduced the plasma level of acylated GHRL and the percentage of acylated GHRL to values below those in animals treated with saline alone (7.03+/-1.35% vs. 2.60+/-0.49%). Our findings support the hypothesis that an adaptive upregulation of the ghrelin receptor may occur during cancer chemotherapy-associated dyspepsia. This may have a role in defensive responses to toxic challenges to the gut. In addition, our results provide preliminary evidence for glucocorticoid modulation of plasma ghrelin levels.

Ghrelin alleviates cancer chemotherapy-associated dyspepsia in rodents.

PURPOSE: Chemotherapy treatment may lead to delayed gastric emptying, early satiety, anorexia, nausea and vomiting, described collectively as the cancer-associated dyspepsia syndrome (CADS). METHOD: We examined the effects of ghrelin in rodent models of CADS induced by treatment with cisplatin. RESULTS: In rats, increased gastric contents and reduced feeding were observed 48 h after injection with cisplatin (6 mg/kg, i.p.). Ghrelin (0.5 mg/kg, i.p.) caused a 16-fold increase in food intake over 1 h in cisplatin/ghrelin-treated rats compared to cisplatin/vehicle-treated rats. A single dose of ghrelin also restored the decreased locomotor activity in rats induced by cisplatin to almost the same level of saline-treated rats. In mice, daily food intake was significantly decreased at 24 h (60%) and 48 h (74%) after cisplatin (20 mg/kg, i.p.). Ghrelin (1 mg/kg, i.p.x2) significantly increased food intake measured at the 48 h time-point in both saline/ghrelin-treated and cisplatin/ghrelin-treated mice, with this effect being most marked in the cisplatin-treated group, where a twofold increase in feeding was observed. In cisplatin-treated mice, delayed gastric emptying was indicated by a 7.7-fold increase in the wet weight of gastric contents and ghrelin improved the gastric emptying index (GEI) by 31% (P < 0.01). CONCLUSION: Together, these results suggest that it is possible to model cancer chemotherapy-induced dyspepsia in rodents and that ghrelin can greatly alleviate the behaviours associated with this syndrome. Agonists at the ghrelin receptor may, therefore, become a useful human therapeutic for this disorder.

Behavioural and hypothalamic molecular effects of the anti-cancer agent cisplatin in the rat: A model of chemotherapy-related malaise?

Many cancer patients receiving chemotherapy experience fatigue, disturbed circadian rhythms, anorexia and a variety of dyspeptic symptoms including nausea. There is no animal model for this 'chemotherapy-related malaise' so we investigated the behavioural and molecular effects of a potent chemotherapeutic agent, cisplatin (CP, 6 mg/kg, i.p.) in rats. Dark-phase horizontal locomotor activity declined post-CP reaching a nadir on day 3 (P < 0.001), before recovering after 7 days. CP's effect was most marked in the late part (05.00-07.00) of the dark-phase. Food intake reached a nadir (P > 0.001) at 2 days, coincident with an increase in gastric contents (cisplatin 9.04+/-0.8 vs. saline 2.32+/-0.3 g; P < 0.001). No changes occurred in hypothalamic mRNA expression for AGRP, NPY, HCRT, CRH, IL-1, IL-6, TNFalpha, ABCG1, SLC6A4, PPIA and HPRT mRNA but tryptophan hydroxylase (TPH) mRNA was decreased (47%, P < 0.05) at day 21 post-CP. This shows that despite marked behavioural effects of cisplatin, only a discrete change (TPH) was found in hypothalamic mRNA expression and that occurred when the animals' behaviour had recovered. Findings are discussed in relation to the neuropharmacology of chemotherapy-induced malaise.

Leptin expression in the fetus and placenta during mouse pregnancy.

During pregnancy, leptin concentrations in the maternal circulation are elevated in both humans and rodents but decrease to pre-pregnancy levels at birth, suggesting a role for leptin in the maintenance of pregnancy. Synthesis of leptin by the human placenta is established but whether the murine placenta synthesizes leptin remains controversial. The aims of this study were to determine (a) if the mouse wild-type placenta expresses the ob gene using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and (b) whether the mouse fetus and placenta contribute to the significant increase of leptin in the maternal circulation during pregnancy. The mouse placenta did not express the ob gene at a level that could be readily detected using RT-PCR. Moreover, both maternal gain in weight and undetectable concentrations of leptin in sera in leptin-deficient ob/ob mothers bearing heterozygote (ob/+) fetuses suggested that the mouse fetus and placenta do not make a significant contribution to the dramatic increase in maternal plasma concentrations of leptin during late gestation. It is therefore concluded that neither fetal- nor placental-derived leptin modulates maternal weight gain during pregnancy.

Leptin requirement for conception, implantation, and gestation in the mouse.

The ob/ob mouse has a complete absence of circulating leptin, resulting in obesity and infertility. Using the minimum daily dose of leptin required to maintain normal body weight and sexual maturation (5 mg/kg, ip), leptin-treated ob/ob females were mated with either wild-type (+/+) or leptin-treated ob/ob males. The leptin treatment continued throughout pregnancy until weaning or was withdrawn at 0.5, 3.5, 6.5, or 14.5 d post coitum (dpc). Normal pregnancy and parturition with pups of normal weight resulted when ob/ob females were mated with +/+ males and leptin treatment was continued throughout pregnancy (6 of 8 pregnancies), to 14.5 dpc (6 of 8 pregnancies), or to 6.5 dpc (9 of 12 pregnancies). Pregnancy did not result when treatment was stopped at 3.5 dpc (1 of 7 pregnancies) or 0.5 dpc (0 of 6 pregnancies). Similar results were obtained when leptin-treated ob/ob females were mated with leptin-treated ob/ob males. The newborn pups failed to survive after birth in groups treated with leptin up to 14.5 and 6.5 dpc despite reinstating leptin at birth. This appeared to be due to a lack of development of the mammary glands. In conclusion, we have shown that leptin is essential for normal preimplantation and/or implantation processes. It is also essential for normal development of the mammary glands, but is not required for pregnancy and parturition once implantation is established.

Interparental conflict, children's social cognitions, and child aggression: a test of a mediational model.

Although correlations between interparental conflict and child maladjustment are well-established, the processes connecting these 2 phenomena are less understood. The present study tested whether an aggressogenic cognitive style mediates the relationship between interparental conflict and child aggression. A multiethnic sample of 115 families with a child between the ages of 7 and 13 years participated. Questionnaires were used to assess parents' and children's perceptions of interparental conflict, children's social problem-solving strategies and beliefs about aggression, and parent and teacher reports of child aggression. Support was found for the mediating effect of aggressogenic cognitions on children's school aggression but not on children's aggression at home. Implications for understanding the associations among interparental conflict, children's social cognitions, and child aggression in different environmental contexts are discussed.

Lack of c-kit mutation in familial urticaria pigmentosa.

Somatic mutations within c-kit have been reported in individuals with mastocytoses, including urticaria pigmentosa (UP). We have identified three siblings with UP. We aimed to determine whether the c-kit proto-oncogene was playing a part in the aetiology of UP in these three siblings. Using seven microsatellite repeat markers spanning an 8-cM interval encompassing the c-kit gene we followed the transmission of the c-kit gene in this family. Furthermore, single-strand conformation polymorphism analysis was used to scan exon 17 of the c-kit gene for mutations in genomic DNA of all family members and somatic DNA extracted from skin of the eldest affected sibling, the proband. No mutations were found in exon 17 in either genomic DNA of all family members or somatic DNA of the proband. Patients with UP have been shown to possess somatic mutations of the c-kit gene. However, this locus has been excluded as playing a part in the three siblings examined here in whom a second gene locus must be determining their UP. Therefore, this study emphasizes genetic heterogeneity in UP. Future study to identify primary molecular determinants of UP should include affected sib-pair studies.

Marital conflict, family processes, and boys' externalizing behavior in Hispanic American and European American families.

Used self-report and observational measures to explore associations among marital conflict, triadic family processes, and child adjustment in Hispanic American, European American, and biethnic families. One hundred and thirteen families with a 7- to 11-year-old son participated. More similarities than differences were found between European American and Hispanic American families. A hierarchical parenting style was associated with externalizing behaviors for European American and biethnic families but not for Hispanic American families. Marital conflict and disengaged family alliances were associated with child externalizing behavior for all ethnic groups. Ethnicity was not found to moderate the relation between marital conflict and family functioning, and greater levels of marital conflict were associated with disengaged family interactions and also with lax or inconsistent parenting. Implications for understanding cross-ethnic issues in family systems and child adjustment are discussed.

Methylenetetrahydrofolate reductase polymorphism (C-677T) and coronary artery disease.

1. Many studies have shown that hyperhomocysteinaemia is a risk factor for atherosclerotic vascular disease. A mutation (C-677T) in the gene coding for the methylenetetrahydrofolate reductase (MTHFR) enzyme has been shown to produce a thermolabile form of the enzyme. Homozygosity for this mutation has been correlated with an elevated plasma homocysteine concentration. The present study aimed to determine whether this mutation was a risk factor for coronary artery disease (CAD). This was achieved by comparing the frequency of the C-677T mutation in patients with angiographically proven CAD against angiographically normal patients in two separate U.K. samples. The analysis was repeated with CAD patients split into those with >=99% stenosis of arteries and those without, to establish whether the C-677T mutation could be correlated with severity of CAD.2. Two patient groups were selected from London and Sheffield. The London group comprised 174 cases and 148 controls. The Sheffield group comprised 93 cases and 85 controls. The DNA samples of the patients were genotyped by polymerase chain reaction and restriction enzyme digestion.3. For London the homozygous C-677T frequencies were: 0.07 (controls), 0.09 (CAD without >=99% stenosis) and 0.10 (CAD with >=99% stenosis). For Sheffield the homozygous C-677T frequencies were: 0.08 (controls), 0.10 (CAD without >=99% stenosis) and 0.11 (CAD with >=99% stenosis). No association was found between the C-677T mutation and CAD in our sample geographical groups. Statistical comparison by genotype distribution for 0 VD (no vessel disease, i.e. 0% diameter reduction in all epicardial arteries) versus CAD without >=99% stenosis: London, P=0.19; Sheffield, P=0.53; 0 VD versus CAD with >=99% stenosis: London, P=0. 23; Sheffield, P=0.55.

Practitioner review: problems in children's peer relations: what can the clinician do?

This paper describes the assessment and treatment of children with peer relationship problems. The first part of the paper is organized around five topics: peer rejection, peer neglect, the absence of friendships, reputation in the peer group, and peer group affiliations. Next, a series of assessment methods is delineated, including peer, teacher, parent and self reports, as well as direct observational procedures. Finally, we suggest a number of treatment options, including social skills training, social cognitive interventions, and co-operative group interventions.