Characterization of the hydroxycarboxylic acid receptor 2 in cats.

The hydroxycarboxylic acid receptor 2 (HCA2) belongs to a family of nutrient-sensing receptors that bind ß-hydroxybutyrate, an alternative fuel source produced during a negative energy balance. The HCA2 receptor has not been identified or characterized in cats. Therefore, the following were the objectives of this study: (1) identify the feline HCA2 receptor protein sequence and compare against known human and rodent sequences, (2) determine tissue distribution and relative expression in lean, healthy cats, and (3) demonstrate in vitro functionality in feline adipose tissue. Tissues (n = 6) and primary adipocytes (n = 4) were collected from lean, healthy, female cats. The published genomic sequence for cats was used to design primers for polymerase chain reaction isolation of HCA2. Relative tissue distribution was evaluated using reverse transcriptase-polymerase chain reaction with RNA isolated from 9 different tissues (spleen, pancreas, lymph node, jejunum, kidney, liver, heart, and subcutaneous and abdominal adipose tissue). Receptor function was evaluated in primary feline adipocyte culture, and changes were compared with basal lipolysis. The in silico predicted feline HCA2 protein sequence exhibited 83.1% and 86.5% amino acid similarity to human and mouse sequences, respectively. The feline HCA2 receptor is predominantly expressed in adipose tissue and spleen. Exposure of feline adipocytes to niacin, a pharmacologic ligand of HCA2, inhibited lipolysis to a similar degree as insulin, a potent lipolytic inhibitor. In conclusion, the feline HCA2 receptor is similar to human and murine receptors in sequence, distribution, and functionality. By gaining a better understanding of the HCA2 receptor in cats, we will be able to better manage feline patients.

Characterization of HOX gene expression in canine mammary tumour cell lines from spontaneous tumours.

Spatial/temporal controls of development are regulated by the homeotic (HOX) gene complex and require integration with oncogenes and tumour suppressors regulating cell cycle exit. Spontaneously derived neoplastic canine mammary carcinoma cell models were investigated to determine if HOX expression profiles were associated with neoplasia as HOX genes promote neoplastic potential in human cancers. Comparative assessment of human and canine breast cancer expression profiles revealed remarkable similarity for all four paralogous HOX gene clusters and several unlinked HOX genes. Five canine HOX genes were overexpressed with expression profiles consistent with oncogene-like character (HOXA1, HOXA13, HOXD4, HOXD9 and SIX1) and three HOX genes with underexpressed profiles (HOXA11, HOXC8 and HOXC9) were also identified as was an apparent nonsense mutation in HOXC6. This data, as well as a comparative analysis of similar data from human breast cancers suggested expression of selected HOX genes in canine mammary carcinoma could be contributing to the neoplastic phenotype.

Blood lipids and first-ever ischemic stroke/transient ischemic attack in the Bezafibrate Infarction Prevention (BIP) Registry: high triglycerides constitute an independent risk factor.

BACKGROUND: Despite unclear associations between blood lipids, including fractionated cholesterol and triglycerides, and stroke, recent evidence demonstrates that lipid-modifying agents decrease the risk of stroke in patients with coronary heart disease (CHD). METHODS AND RESULTS: Patients with documented CHD who were screened for but not included in the Bezafibrate Infarction Prevention study and had no history of stroke or transient ischemic attack (TIA) (n=11 177) were followed up. At baseline, medical histories were obtained and blood lipids assessed at a central study laboratory. During a 6- to 8-year follow-up period, 941 patients were identified as having nonhemorrhagic cerebrovascular disease, of whom 487 had verified ischemic stroke (per clinical findings and brain CT) or TIA. Patients experiencing an ischemic stroke/TIA had higher mean levels of triglycerides, lower levels of HDL cholesterol, and lower percentages of cholesterol contained in the HDL cholesterol moiety (%HDL; P<0.01 for all). In a logistic regression model, the adjusted ORs for developing an ischemic stroke/TIA were 1.27 (95% CI 1.01 to 1.60) associated with triglycerides >200 mg/dL and 0.87 (95% CI 0.78 to 0.97) associated with a 5% decrease in %HDL. The increased risk associated with high triglycerides was found across subgroups of age, sex, patient characteristics, and cholesterol fractions. CONCLUSIONS: High triglycerides constitute an independent risk factor for ischemic stroke/TIA across subgroups of age, sex, patient characteristics, and cholesterol fractions, whereas high %HDL was an independent protective factor among patients with CHD. These findings support the role of blood lipids, including triglycerides, as important modifiable stroke risk factors.

A prospective study of plasma fibrinogen levels and the risk of stroke among participants in the bezafibrate infarction prevention study.

PURPOSE: Plasma fibrinogen has emerged as an important predictor of cardiovascular disease, but few data are available on its association with stroke. We sought to determine if plasma fibrinogen is a marker of increased risk or a direct causative risk factor for stroke. SUBJECTS AND METHODS: Patients from the Bezafibrate Infarction Prevention Study, a placebo-controlled, randomized clinical trial of secondary prevention of coronary heart disease by lipid modification with bezafibrate retard (400 mg daily), were studied. Plasma fibrinogen levels were measured at baseline and yearly thereafter. Stroke, a prospectively monitored endpoint, was systematically assessed regarding stroke type, subtype, and functional outcome. RESULTS: Mean baseline fibrinogen levels were significantly higher in patients subsequently having a cerebrovascular event (140 strokes, 36 transient ischemic attacks; mean follow-up, 6.2 years) than in patients who did not (375 vs. 349 mg/dL, P <0.0001). Fibrinogen levels did not differ significantly by the type, subtype, or severity of the cerebrovascular event. Risk of ischemic stroke increased from 3.3% in the lowest tertile (baseline fibrinogen <314 mg/dL) to 7.% in the middle tertile (fibrinogen 314 to 373 mg/dL) to 10% in the upper tertile (fibrinogen >373 mg/dL, P <0.001). Adjusting for age, blood pressure, and other covariates, fibrinogen levels in the upper tertile were associated with more than a twofold increase in risk of ischemic stroke compared with in the lowest tertile (hazard ratio = 2.6; 95% confidence interval: 1.5 to 4.3). We did not find fibrinogen change from baseline to be related to subsequent ischemic stroke events. CONCLUSION: Plasma fibrinogen is a strong predictor of, rather than a direct causative factor for, subsequent stroke among patients at increased risk owing to manifest coronary heart disease.

The influence of three months of methylphenidate treatment on platelet-poor plasma biogenic amine levels in boys with attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is related to dysregulation in the activity of brain monoamines. The aim of the present study was to assess the impact of three months' methylphenidate (MPH) treatment on platelet-poor plasma (PPP) norepinephrine (NE), dopa and serotonin (5-HT) levels as well as on ADHD symptomatology. Three months of MPH treatment in 16 ADHD boys, aged 11.4 +/- 1.6 years, resulted in a significant reduction in PPP NE levels (p < 0.05). A tendency towards a reduction of PPP 5-HT and dopa levels was detected (p < 0.1 for both). The decrease in PPP biogenic amine levels after three months of MPH treatment was accompanied by a significant reduction in all psychometric characteristics of ADHD. This result indicates the possible role of overactivity of the noradrenergic system in the pathophysiology of ADHD and suggests that the MPH therapeutic action may be related to stimulant-induced inhibitory effect on the noradrenergic system. Copyright 2001 John Wiley & Sons, Ltd.

Clinical impact of borderline and undiagnosed diabetes mellitus in patients with coronary artery disease.

The present study was aimed to evaluate the prevalence and prognostic significance of unrecognized and newly defined borderline diabetes (with fasting blood sugar 126 to 139 mg/dl) by the American Diabetes Association criteria in coronary patients over a 7.7-year follow-up. Both undiagnosed and newly diagnosed borderline diabetes were associated with an unfavorable metabolic profile. The mortality of the borderline diabetics tended to be higher than in their nondiabetic counterparts. but this tendency did not reach statistical significance. A significant excess in long-term mortality was observed among the undiagnosed diabetes group.

Prospective evaluation of circulatory levels of catecholamines and serotonin in neuroleptic malignant syndrome.

OBJECTIVE: Neuroleptic malignant syndrome (NMS) may be associated with a dysregulation of the catecholaminergic and serotonergic systems. The objective of the present study was to evaluate prospectively the circulatory levels of serotonin (5-HT), epinephrine (E) and dopa in patients suffering from NMS. METHOD: Platelet-poor plasma (PPP) levels of serotonin, epinephrine and dopa in eight NMS patients were measured twice: in the acute state and in the state of remission. RESULTS: PPP dopa concentration was significantly lower in acute NMS state compared to the remission state (P = 0.023). In contrast, PPP E level was significantly higher (P = 0.019) in the acute NMS state and PPP 5-HT concentrations in the acute state tended to be higher than those at remission (P = 0.078). 5-HT/dopa ratio was significantly higher in the acute NMS (P = 0.015). CONCLUSION: These results may reflect reduction in dopaminergic function and increase in adrenergic and serotonergic activity in the acute NMS state.

The effect of mini-dose aspirin on renal function and uric acid handling in elderly patients.

OBJECTIVE: Aspirin is known to have a bimodal effect on the renal handling of uric acid (UA). High dosages (>3 gm/day) are uricosuric, while low dosages (1-2 gm/day) cause UA retention. Although very-low-dose (mini-dose) aspirin is used increasingly as a platelet aggregation inhibitor, no studies have been published on whether aspirin's renal effects occur at dosages of <0.5 gm/day. The aim of the present study was to evaluate the effects of commonly used mini-dosages of aspirin on renal function and UA handling in elderly patients. METHODS: The study included 49 elderly inpatients (age 61-94). Patients were excluded if they had renal failure, hyperuricemia, gout, or a history of bleeding, or if they were receiving anticoagulants, aspirin, or nonsteroidal antiinflammatory drugs. Previous medications and diet were kept unchanged. Aspirin was administered as follows: 75 mg/day (week 1), 150 mg/day (week 2), 325 mg/day (week 3), and 0 mg/day (week 4). Baseline and weekly samples of blood and urine were evaluated for UA, creatinine, blood urea nitrogen, creatinine clearance, UA excretion, UA clearance, and plasma levels of aspirin. RESULTS: At the lowest dosage, aspirin caused a 15% decrease in the rate of UA excretion (P = 0.045 by t-test), which was associated with a slight but significant increase in serum levels of UA (P = 0.009). These effects on UA levels were gradually reduced with increasing dosages of aspirin (multivariate analysis of variance with repeated measures showed no statistically significant difference in the rate of UA excretion between weeks 1-3 and week 0 [baseline], but the difference in serum UA levels for the same comparison was statistically significant [P = 0.038]). Generally, creatinine and UA clearance rates paralleled each other during aspirin treatment. However, 1 week after aspirin was discontinued, creatinine clearance remained decreased while UA clearance returned to baseline. Plasma aspirin concentrations were low and variable. However, patients with above-median aspirin levels had significantly greater changes in serum creatinine levels, urinary UA excretion rates, and UA clearance rates following the first week of aspirin treatment. Hypoalbuminemia and concomitant treatment with diuretics enhanced the effects of aspirin on renal function and UA retention. CONCLUSION: Mini-dose aspirin, even at a dosage of 75 mg/day, caused significant changes in renal function and UA handling within 1 week in a group of elderly inpatients, mainly in those with preexisting hypoalbuminemia. Given the widespread (and often unmonitored) use of mini-dose aspirin, especially among the elderly, these findings call for clinician alertness as well as for further studies to clarify the mechanisms underlying these phenomena.

Effect of raloxifene-analog (LY 117018-Hcl) on the bone marrow of ovariectomized mice.

The effects of LY117018-Hcl (Ralox-A) on body metabolism and differentiation of bone marrow cells were studied in ovariectomized (OVX) mice. We used a mouse model in which estrogen depletion was established for a period of three months before treatment. After that period the animals were divided into three experimental groups consisting of sham-operated, OVX, and OVX-Ralox-A-treated mice. The OVX animals received daily treatment of Ralox-A during two time periods (35 and 65 days). After the treatment we measured the serum levels of protein, ion(s), lipid content, liver, and kidney functions. Our findings indicated that a change in hormonal state did not affect basic body metabolism except for causing an increase in triglycerides (TG) in the OVX mice, which was lowered by the Ralox-A. A higher alkaline phosphatase (ALK-P) level was observed in serum of the OVX-Ralox-A-treated mice than in serum of the OVX mice. We investigated the effects of estrogen depletion on the differentiation of hematopoietic and stromal cells that directly affect bone resorption and formation. OVX and OVX-treated mice were compared with the sham group and assessed for the alteration of these cells' differentiation. The proliferation of stromal stem cells was measured by CFU-F assay in vitro. A decrease in CFU-F colonies derived from OVX mice was observed and after the Ralox-A treatment the number of CFU-F reached sham levels. On the contrary, an upregulation of myeloid cells was observed when analyzed by FACS and by granulocyte/macrophage-colony forming unit (G/M-CFU) assay in selective culture conditions. The G/M-CFUs were increased in the OVX mice and were reduced to sham levels after Ralox-A treatment. In this study, we demonstrated cellular changes of stromal and hemopoietic cells in OVX mice and a beneficial Ralox-A effect that protected such cellular changes.

The status of serum iron and transferrin saturation in acute non-hepatotrophic viral infections.

Elevation of serum iron is frequently observed in patients' with chronic Hepatitis C virus infection and was found to be a negative predictive factor for treatment response. We prospectively evaluated the iron status of 112 patients with acute viral infection not due to hepatitis viruses. The virus infections included Epstein-Barr virus (57%), cytomegalovirus (22.3%) and others (20.7%). Increased serum iron was documented in two patients only. Out of nine patients who were evaluated twice, seven had increased serum iron but the level remained well within the normal range. Transferrin saturation was normal in all patients. Disturbed liver function tests were documented in 30-40% of patients. We conclude that serum iron is not significantly increased during acute non (A-E) hepatitis viral infections with or without liver involvement.

Elevated serum triglyceride levels and long-term mortality in patients with coronary heart disease: the Bezafibrate Infarction Prevention (BIP) Registry.

BACKGROUND: The association between elevated blood triglyceride levels and subsequent mortality risk in patients with established coronary heart disease (CHD) has been investigated rarely. The aim of the present study was to investigate this association. METHODS AND RESULTS: We evaluated mortality over a mean follow-up time of 5. 1 years among 9033 male and 2499 female CHD patients who were screened for participation in the Bezafibrate Infarction Prevention (BIP) Study. A stepwise increase in mortality with increasing serum triglyceride levels was observed in patients with desirable or elevated serum total cholesterol levels and in patients with either desirable or abnormally low HDL cholesterol levels. Multivariate adjustment for factors other than HDL cholesterol yielded a slightly increased adjusted mortality risk with a 1-natural-log-unit elevation of triglyceride levels in men (hazard ratio [HR] 1.14, 95% CI 1.00 to 1.30) and women (HR 1.37, 95% CI 1.04 to 1.88). Excess covariate-adjusted risk was noted among patients with elevated total and LDL cholesterol and in women with HDL cholesterol levels >45 mg/dL. After additional adjustment for HDL cholesterol, the risk of mortality with a 1-natural-log-unit elevation of triglycerides declined in men (HR 1.09, 95% CI 0.94 to 1.26) and in women (HR 1.10, 95% CI 0.80 to 1.50). A trend for increased mortality risk remained in patients with elevated total and LDL cholesterol and in women with HDL cholesterol >45 mg/dL. CONCLUSIONS: Elevated triglyceride levels were associated with a small, independent increased mortality risk in CHD patients. This risk may be increased among subgroups of patients with elevated total cholesterol and LDL cholesterol levels.

Hypertension in diet versus pharmacologically treated diabetics: mortality over a 5-year follow-up.

The natural history of non-insulin-dependent diabetes mellitus (NIDDM) differs markedly between patients with diet treated and pharmacologically treated disease. However, the interrelationship between hypertension and these common diabetes types has not been specifically addressed in previous studies. This study was designed to evaluate the prognostic significance and prevalence of hypertension in coronary patients with diet versus pharmacologically treated NIDDM over a 5-year follow-up period. The study sample comprised 11 515 patients aged 45 to 74 years with a previous myocardial infarction and/or anginal syndrome who had been screened but were not included in the Bezafibrate Infarction Prevention study. Among them, 9033 were nondiabetics and 2482, diabetics (987 diet treated and 1495 pharmacologically treated). The prevalence of hypertension among nondiabetics, diet-treated diabetics, and pharmacologically treated diabetics was 31%, 42%, and 43%, respectively. Crude all-cause mortality (CM) was lower in the nondiabetic patients (11.2% versus 22.0%; P<0.001). Among diabetics, 548 patients died: 81 diet treated normotensives (CM 14%); 100 diet-treated hypertensives (CM 24.4%); 205 pharmacologically treated normotensives (CM 24.2%); and 162 pharmacologically treated hypertensive patients (CM 25.0%). Age-adjusted mortality was lowest for the normotensive patients in the diet-treated group and highest for the hypertensive pharmacologically treated patients. Multivariate analysis shows that hypertension is a strong and independent predictor of increased CM in diet-treated but not in pharmacologically treated NIDDM: hazard ratio (HR) was 1.68 (95% confidence interval [CI] 1.24 to 2.29) for the diet-treated versus 1. 01 (95% CI 0.82 to 1.26) for the pharmacologically treated diabetics. The contribution of hypertension to stroke mortality was substantial for both diet treated and pharmacologically treated NIDDM: hazard ratios were 3.17 (95% CI 1.12 to 8.98) and 2.21 (95% CI 0.72 to 6.77), respectively. The increased risk of mortality associated with hypertension in relatively mild diet-treated NIDDM strongly supports the clinical benefit of early blood pressure control among diabetic patients with ischemic heart disease.

Low platelet-poor plasma concentrations of serotonin in patients with combat-related posttraumatic stress disorder.

BACKGROUND: Combat-related posttraumatic stress disorder (CR-PTSD) is associated with a dysregulation of various neurotransmitter systems. METHODS: We assessed levels of platelet-poor plasma (PPP) norepinephrine (NE), and serotonin (5-HT), and 24-hour urinary excretion of NE, dopamine (DA), and homovanillic acid (HVA) in 17 male outpatients with untreated chronic CR-PTSD (age, 33.1 +/- 7.4 years) and 10 normal control subjects (age, 35.8 +/- 2.7 years). RESULTS: Compared with the control subjects, the PTSD patients showed significantly lower PPP 5-HT levels, elevated PPP NE levels, and significantly higher mean 24-hour urinary excretion of all three catecholamines (NE, DA, and HVA). The 24-hour urinary HVA values of the CR-PTSD patients correlated significantly and positively with the total Impact of Event Scale scores and the avoidance symptoms cluster scores, and the PPP 5-HT levels correlated negatively with the Hamilton Anxiety Rating Scale scores. The PPP NE/5-HT ratio was significantly higher in the study group than in the control subjects. CONCLUSIONS: We believe this combined enhanced noradrenergic activity and diminished 5-HT activity may be relevant to the neurobiology of CR-PTSD.

Continuous intravenous octreotide treatment for acute experimental pancreatitis.

BACKGROUND: The efficacy of octreotide, the synthetic analogue of the hormone somatostatin, for the treatment of acute pancreatitis is controversial. Octreotide has been commonly administered in subcutaneous bolus injections; however, continuous intravenous infusion may be advantageous for acute conditions. METHODS: Acute experimental pancreatitis was induced in rats by intraparenchymal injections of 1 ml 10% sodium taurocholate, and octreotide (1 microg/kg/h, dissolved in physiological solution, intravenously was started 4 h later and continuously infused for 48 h. Physiological solution infusions, in identical volumes, were used in the controls. The following parameters were examined: mortality; macroscopic and histological damage; hematocrit; plasma pH; acid-base balance; serum glucose; calcium, and amylase. RESULTS: Octreotide treatment had a striking effect on mortality: 8.3 versus 91.6% in the treatment and control groups, respectively (p < 0.001). Octreotide also ameliorated pancreatic edema and intestinal dilatation, and had significant beneficial effects on histopathological damage and the biochemical alterations which are associated with acute pancreatitis. CONCLUSIONS: Continuous intravenous octreotide infusion is a potentially efficacious therapeutic method for acute pancreatitis.

Effects of aspirin treatment on survival in non-insulin-dependent diabetic patients with coronary artery disease. Israeli Bezafibrate Infarction Prevention Study Group.

PURPOSE: The benefit of aspirin treatment among diabetic patients with chronic coronary artery disease is not well established. The purpose of this study was to assess the effect of aspirin on cardiac and total mortality in a large cohort of diabetic patients with established coronary artery disease and to compare it with the effect of aspirin in nondiabetic counterparts. PATIENTS AND METHODS: In this observational study among patients screened for participation in the Bezafibrate Infarction Prevention Study, the effects of aspirin treatment in 2,368 non-insulin-dependent diabetic patients with coronary artery disease were compared to those in 8,586 nondiabetic patients. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated with proportional hazards models. RESULTS: Fifty-two percent of diabetic patients and 56% of nondiabetic patients reported aspirin therapy. After 5.1 +/- 1.3 (mean +/- SD) years of follow-up, the absolute benefit per 100 patients treated with aspirin was greater in diabetic patients than in nondiabetic patients (cardiac mortality benefit: 5.0 versus 2.1, and all-cause mortality benefit: 7.8 versus 4.1). Overall cardiac mortality among diabetic patients treated with aspirin was 10.9% versus 15.9% in the nonaspirin group (P < 0.001), and all-cause mortality was 18.4% and 26.2% (P < 0.001). After adjustment for possible confounders, treatment with aspirin was an independent predictor of reduced overall cardiac (HR = 0.8; 95% CI: 0.6-1.0) and all-cause mortality (HR = 0.8; 95% CI: 0.7-0.9) among diabetic patients, similar to those in nondiabetic patients. CONCLUSION: Treatment with aspirin was associated with a significant reduction in cardiac and total mortality among non-insulin-dependent diabetic patients with coronary artery disease. The absolute benefit of aspirin was greater in diabetic patients than in those without diabetes.

Diminished suicidal and aggressive behavior, high plasma norepinephrine levels, and serum triglyceride levels in chronic neuroleptic-resistant schizophrenic patients maintained on clozapine.

Impulsiveness and aggressiveness may be the most common behavioral correlates of central serotonergic dysfunction. The aim of this study was to determine whether clozapine, an atypical antipsychotic agent with a potent serotonergic antagonistic activity, affects impulsiveness and aggression. Its effects on serum lipids, platelet-poor plasma serotonin (5-HT), and norepinephrine (NE) levels were also studied. Thirty neuroleptic-resistant chronic schizophrenic patients, maintained on clozapine for 1 year, were evaluated for aggressiveness, impulsiveness, and suicidality in comparison with 30 chronic schizophrenic patients maintained on classical antipsychotic agents for the same period of time. Clozapine treatment was associated with less impulsiveness (p < 0.05), aggressiveness (p < 0.01) and fewer suicidal attempts (p < 0.05). Serum triglycerides and plasma NE levels were significantly higher (p < 0.01 and p < 0.0001, respectively) in the patients treated with clozapine, as compared with patients treated with classical neuroleptic drugs. The authors conclude that long-term clozapine treatment may be effective in controlling aggressive, impulsive, and suicidal behavior in neuroleptic-resistant chronic schizophrenic patients. The elevated plasma NE levels in patients treated with clozapine as compared to those treated with classical neuroleptic drugs may be relevant for the anti-aggressive/antisuicidal activity of clozapine.

Major locus influencing plasma APO-A1 levels also controls plasma HDL3-C concentrations.

Elevated plasma levels of apolipoprotein A1 (APO-A1) and high-density lipoprotein cholesterol (HDL-C) are important protective factors for atherosclerosis and coronary heart disease. Using the data on plasma concentrations of APO-A1, and HDL-C particles HDL2-C and HDL3-C in 970 Israeli individuals belonging to 228 pedigrees, we tested the hypothesis that a major locus influencing interindividual variation in APO-A1 levels also controls interindividual variation in HDL3-C and HDL2-C levels. Univariate and bivariate complex segregation analyses, as implemented in two statistical packages (MAN-3 and PAP-4.0) were applied to test the hypothesis. The results of the analysis clearly indicated the possibility of major gene involvement in the determination of plasma concentration variation of each of the 3 study variables. The results provide strong evidence in support of our hypothesis that HDL3-C genetic variation fully depends on the APO-A1 major locus. In particular, environmental and sporadic models were strongly rejected (P < 0.001) in bivariate analysis. The hypothesis of no pleiotropic effect of the putative APO-A1 locus on HDL3-C transmission was also unequivocally rejected (P < 0.001), while the bivariate Mendelian model was accepted (P > 0.05). The results of bivariate analysis of APO-A1 effect on HDL2-C were not clear. They indicated the possibility of the existence of slight genetic covariation between the two variables, and as yet we were unable to decipher the mode of covariation with the applied models.

The absorption of low-dose methotrexate in patients with inflammatory bowel disease.

BACKGROUND: Recent clinical trials have demonstrated that methotrexate may have an important therapeutic role in the treatment of patients with inflammatory bowel disease, who are either refractory or intolerant to traditional medical therapy. The aim of this study was to evaluate the pharmacokinetics of low-dose oral methotrexate in patients with inflammatory bowel disease. METHODS: Methotrexate (12.5 mg) was given orally to nine patients with inflammatory bowel disease: five with Crohn's disease, and four with ulcerative colitis, and to six patients with rheumatoid arthritis who served as a control group. Blood samples were drawn at specific intervals to evaluate methotrexate plasma levels. RESULTS: Methotrexate was rapidly absorbed in all patients. Peak concentrations (Cmax) varied considerably, ranging from 0.25-0.87 micro M. The mean Cmax values were similar in all patient groups (0.59 +/- 0.12, 0.69 +/- 0.16 and 0.54 +/- 0.18 micro M, P not significant) for Crohn's disease, ulcerative colitis and rheumatoid arthritis, respectively. The mean area under curve in 120 min (AUC0-120) was also similar in all patient groups (32.9 + 11.3, 43.6 + 9.9 and 41.8 + 14.9 ng.min/mL, P not significant) for Crohn's disease, ulcerative colitis and rheumatoid arthritis, respectively. The mean time to reach Cmax, (tmax), varied between patient groups (84, 112 and 95 min, respectively, with a significant difference, P < 0.02, between the Crohn's disease and ulcerative colitis groups. A negative correlation was found between methotrexate dosage/kg and Cmax (r = -0.74) only in Crohn's disease patients but not in the other patient groups. CONCLUSIONS: Orally administered methotrexate is well absorbed in patients with inflammatory bowel disease including those with severe small bowel disease or resection. If methotrexate is proven to be effective in inflammatory bowel disease, it should be administered orally.

The influence of Vicia faba (broad bean) seedlings on urinary sodium excretion.

Dopamine (DA) is known to increase diuresis and natriuresis through its action on renal dopaminergic receptors. Augmentation of intra-renal DA concentration by enhancement of its in situ production is greatly dependent on the availability of its precursor L-DOPA to the sites of its renal decarboxylation. Vicia faba (Vf) is a ubiquitous plant rich in easily absorbable L-DOPA. Following ingestion of 40 g freshly chopped Vf containing 120-130 mg of L-DOPA, plasma L-DOPA and urinary sodium and DA excretion increased significantly. The DA/Cre ratio reached a maximum level (280 +/- 58 micrograms/g) 60 minutes after Vf ingestion. This was significantly higher than the DA/Cre ratio after a control meal (1.8 +/- 0.2 micrograms/g; P < 0.0005). The Na/Cre ratio reached the maximal level (2.85 +/- 0.42 mmol/g) 90 minutes after Vf ingestion. This was significantly higher than the Na/ Cre ratio after the control meal (1.4 +/- 0.24 mmol/g; P < 0.005). We suggest that Vf might be of value in treating conditions such as hypertension, heart failure, renal failure, and liver cirrhosis in which natriuresis and diuresis are medically beneficial.

Cys 618 Arg mutation in the RET proto-oncogene associated with familial medullary thyroid carcinoma and maternally transmitted Hirschsprung's disease suggesting a role for imprinting.

The multiple endocrine neoplasia type 2 (MEN2) syndromes and Hirschsprung's disease (HSCR) are inherited neurocristopathies characterized by medullary thyroid carcinoma (MTC), pheochromocytoma, parathyroid disease, and gastrointestinal neuromatosis. Mutations in the RET proto-oncogene are the underlying cause of the MEN2 syndromes and some cases of HSCR. In this report, we show that Cys 618 Arg mutation cosegregates with familial MTC and HSCR in two Moroccan Jewish families in which no involvement of pheochromocytoma or parathyroidism was observed. A single haplotype shared by chromosomes bearing the Cys 618 Arg mutation in both families strongly suggests a founder effect for this mutation. We have observed in our and in several other previously reported families, an excess of maternal over paternal mutated RET alleles in offsprings affected by HSCR. We suggest that parental imprinting may play a role in the ethiology of HSCR caused by mutations in the RET protooncogene.