Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon

We have examined whether dietary polyamines influence the formation and initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in rat colon. Effects of a combination of dietary polyamines at three dose levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g; spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied in animals in two different experimental situations: animals treated with AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a specific inhibitor of endogenous polyamine synthesis. In both experimental situations, dietary polyamines enhanced the growth of ACF, expressed as the number of large ACF (foci with three or more aberrant crypts, ACF > or = 3), whereas the formation of ACF, expressed as the number of ACF, was apparently not altered. In animals treated with AOM alone, maximal growth enhancing effect on ACF was nearly obtained with the median level of dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of DFMO was counteracted by dietary polyamines in a dose- dependent manner, and it was abolished at the highest level of polyamines. In conclusion, it was demonstrated that dietary polyamines are able to enhance the growth of AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused inhibition of ACF growth, probably by compensating for the DFMO-reduced endogenous polyamine synthesis.      

MR imaging of the pituitary gland in children and young adults with congenital combined pituitary hormone deficiency associated with PROP1 mutations

OBJECTIVE: The aim of this study was to clarify the relationship between morphologic changes of the pituitary gland and the genotype of Prophet of Pit-1 (PROP1), a newly discovered gene responsible for congenital combined pituitary hormone deficiency, in a series of eight humans with this disorder. CONCLUSION: Congenital hypoplasia of the anterior pituitary gland is the most common MR imaging finding in patients with combined pituitary hormone deficiency. Our findings suggest a crucial role for PROP1 in pituitary organogenesis as well as anterior pituitary cell differentiation.     

A novel IVS2 -2A>T splicing mutation in the GH-1 gene in familial isolated growth hormone deficiency type II in the spectrum of other splicing mutations in the Russian population

Isolated GH deficiency (IGHD) is characterized by genetic heterogeneity, both in familial and sporadic cases. To determine if this statement can be applied to the Russian population, we performed screening for mutations in the GH-1 gene in children living in Russia with IGHD. Twenty-eight children from 26 families with total IGHD were studied. DNA fragments, covering each of four (2-5) exons of GH-1 were amplified using PCR. Single-strand conformation polymorphism analysis followed by direct DNA sequencing identified five heterozygous mutations of splicing in intron 2, intron 3, and exon 4 of GH-1; three of them were not previously reported. We concentrated here on dominant-negative mutations causing IGHD type II, which were as follows: 1) A>T transversion of the second base of the 3'-acceptor splice site of intron 2 (IVS2 -2A>T); 2) T>C transition of the second base of the 5'-donor splice site of intron 3 (IVS3 +2T>C); 3) G>A transition of the first base of the 5'-donor splice site of intron 3 (IVS3 +1G>A). Our data indicate allelic heterogeneity of IGHD type II (IGHD II). However, all mutations in Russian IGHD II patients affect splicing, a striking difference from the mutation spectrum of other IGHD forms. The IVS2 -2A>T mutation is the first identified mutation in intron 2 of GH-1. The 5'-donor splice site of intron 3 of GH-1 is a mutational hot spot, and the IVS3 +1G>A mutation can be considered to be a common molecular defect in IGHD II in Russian patients.     

Cytospectrophotometric study of glycoproteins of the erythrocyte membrane in renal and spontaneous hypertension in rats]

Spontaneously hypertensive rats (SHR), aged 10 weeks, and rats with renovascular hypertension (25-30 weeks) demonstrated, in contrast to the controls, a different pattern of erythrocytes staining with paraldehyde-fuchsin used in histochemistry for demonstrating glycoproteids. The erythrocytes were found to respond to intravenous glucose injections by changing the optic density. The erythrocytes response of SHR differs from the normals, but no difference was revealed in rats with renovascular hypertension. The authors suggest that the changes in the tinctorial properties of the erythrocytes with reference to paraldehyde-fuchsin indirectly reflect the state of the insulin receptors of the erythrocyte membrane.     

Methodical approaches to the determination of steroid hormone levels in different biological fluids in children with congenital dysfunction of the adrenal cortex

The paper treats of the data on the use of radioimmunoassays for the measurement of steroid hormone content (17-hydroxyprogesterone, testosterone) in blood serum and saliva of children with congenital adrenocortical dysfunction. It is confirmed that these hormones can be detected in saliva only with the aid of highly sensitive and highly specific RIA systems. A positive correlation has been established between hormonal levels in both biological fluids.     

Myocardial hypertrophy and coronary insufficiency as a cause of arrhythmia in patients with hypertension]

AIM: To elucidate contribution of left ventricular hypertrophy (LVH) vs myocardial ischemia to rhythmic disorders in patients with essential hypertension (EH) and LVH. MATERIALS AND METHODS: Echocardiography, coronarography, treadmill test, 24-h ECG monitoring were included in examination of 69, 69, 68 and 63 patients, respectively. All of them had EH stage II and LVH. The comparison was made between the groups composed by LVH degree and by the presence or absence of coronary artery atherosclerosis (CAA). RESULTS: Subjective arrhythmia was recorded in 27% of the examinees, while objective one was registered by 24-h monitoring and treadmill test in 85.7 and 42.6% of the patients, respectively. Ventricular arrhythmia in EH stage II patients with LVH is associated for the most part with coronary insufficiency, often in the presence of atherosclerosis of the coronary artery. High-grade ventricular extrasystoles by B. Lown and M. Wolf and LVH degree were related. CONCLUSION: An essential role in the onset of supraventricular arrhythmia (SVA) in EH stage 2 patients with LVH belongs to the size of the left atrium and LVH degree. SVA is related to left ventricular myocardial ischemia.     

Pharmacodynamics of allapinin and its possible adverse effects

Allapinine (Class IC), a new antiarrhythmic agent, was studied in 76 patients with premature contraction. Allapinine was found to be beneficial both in ventricular and supraventricular premature beats. Oral allapinine usually showed its effect 40-60 minutes following its administration, its maximum action being 4-5 hours later, its duration was some 8 hours. The optimal dose of the drug amounted to 75 mg/day. Larger-dose allapinine produced adverse effects, its lower dosage had no antiarrhythmic effect. The drug failed to affect blood pressure, heart rate, QT interval length. The PQ interval and QRS complex were increased. The side effects were dose-dependent. There was a risk of the drug's arrhythmogenic effect.     

Evasin‐3‐like anti‐chemokine activity in salivary gland extracts of ixodid ticks during blood‐feeding: a new target for tick control

Ticks exploit many evasion mechanisms to circumvent the immune control of their hosts including subversion of the communication language between cells of the immune system provided by chemokines and other cytokines. One subversive molecule secreted in the saliva of Rhipicephalus sanguineus is Evasin‐3, a structurally unique 7 kDa protein that selectively binds the neutrophil chemoattractants, CXCL8 and (with lower affinity) CXCL1. We compared anti‐human CXCL8 and anti‐mouse CXCL1/KC activities in salivary gland extracts prepared from adult Amblyomma variegatum, Rhipicephalus appendiculatus and Dermacentor reticulatus ticks during blood‐feeding. Both anti‐CXCL8 activity and anti‐CXCL1 activity were detected in all species and in both adult females and males, with consistently higher activity levels against CXCL8. These results suggest that Evasin‐3‐like activity is common amongst metastriate ixodid tick species, and provide further evidence of the importance to ticks in controlling neutrophils during blood‐feeding. As such, Evasin‐3 offers a new target for anti‐tick vaccine development.