SNP Group Research Articles

An Alternative Cyclin-D1 Splice Site is Not Linked to Inflammatory Bowel Disease-Associated Neoplasia

Inflammatory bowel diseases (IBD) encompass inflammatory disorders affecting the gastrointestinal tract, primarily ulcerative colitis (UC) and Crohn's disease (CD). The risk of developing colorectal cancer (CRC) is increased in patients with IBD. The CCND1 protein is the regulatory subunit of an enzyme that inactivates the retinoblastoma protein, a tumor suppressor protein, and promotes progression through the G1-S phase of the cell cycle. The CCND1 870G-A gene polymorphism influences susceptibility to colorectal cancer. The mutant allele of CCND1 in IBD-associated neoplasia leads to a greater frequency of alternate splicing during transcription, resulting in a more stable CCND1 protein. This creates a higher concentration of CCND1, facilitating easier passage through the G1/S checkpoint, abnormal cell cycle progression, and possibly carcinogenesis. We conducted a case-control study involving 396 individuals with IBD. IBD subgroups included CD, UC, and indeterminate colitis (IC). We studied patients with sporadic colorectal cancer (n=75) and patients without gastrointestinal disease as a control group (n=93). We extracted DNA from blood and performed polymerase chain reaction followed by high-performance liquid chromatography to screen for mutations. We confirmed the polymorphism at nucleotide A870G in exon 4. For statistical analysis, we used exact analyses of two-way contingency tables. Power calculations were done and correction for multiple testing was performed by computing the false discovery rate (FDR). Our study had a power of 75% at a 0.05 significance level. A870G SNP allele frequency in the IBD group was 44.8%, compared to 51.6% in the control population. Only the IC group showed a significant association with CCND1 splice site after correction for multiple testing (FDR=0.042). There were no differences between the other IBD groups and controls. We found an association between CCND1 A870G SNP and IC group only (p=0.014, FDR=0.042). However, our data do not show an association between CCND1 A870G SNP and CD-associated or UC-associated neoplasia.

Genome-wide association study identifies two novel loci containing FLNB and SBF2 genes underlying stature variation

Human stature, as an important physical index in clinical practice and a usual covariate in gene mapping of complex disorders, is a highly heritable complex trait. To identify specific genes underlying stature, a genome-wide association study was performed in 1000 unrelated homogeneous Caucasian subjects using Affymetrix 500K arrays. A group of seven contiguous markers in the region of SBF2 gene (Set-binding factor 2) are associated with stature, significantly so at the genome-wide level after false discovery rate (FDR) correction (FDR q = 0.034-0.042). Three SNPs in another SNP group in the Filamin B (FLNB) gene were also associated with stature, significantly so with FDR q = 0.042-0.048. In follow-up independent replication studies, rs10734652 in the SBF2 gene was significantly (P = 0.036) and suggestively (P = 0.07) associated with stature in Caucasian families and 1306 unrelated Caucasian subjects, respectively, and rs9834312 in the FLNB gene was also associated with stature in such two independent Caucasian populations (P = 0.008 in unrelated sample and P = 0.049 in family sample). Particularly, additional significant replication association signals were detected in Chinese, an ethnic population different from Caucasian, between rs9834312 and stature in 619 unrelated northern Chinese subjects (P = 0.017), as well as between rs10734652 and stature in 2953 unrelated southern Chinese subjects (P = 0.048). This study also provides additional replication evidence for some of the already published stature loci. These results, together with the known functional relevance of the SBF2 and FLNB genes to skeletal linear growth and bone formation, support that two regions containing FLNB and SBF2 genes are two novel loci underlying stature variation.

Effects of photoperiod on sex steroids and gonad maturation in Arctic charr

Four groups of Arctic charr (age 3+), previously exposed to natural photoperiod, were subjected to different photoperiod regimes from February 20: Simulated natural photoperiod (SNP; Tromsø 70°N), continuous light (LD 24:0) followed by short day (LD 6:18) from either May 1 (L Feb–May) or June 25 (L Feb–June), or continuous light (LD 24:0) throughout the experiment (L Continuous). In females, peak levels of estradiol-17β and testosterone were 6 and 10, 6 and 7, and 3 and 5 weeks advanced, in L Feb–May, L Feb–June and L Continuous, respectively, whereas in males plasma levels of 11-ketotestosterone peaked 8 weeks earlier in L Feb–May and L Feb–June than in SNP and L Continuous. Median ovulation time in L Feb–May and L Feb–June was advanced by 10 weeks compared to SNP and L Continuous, and median spermiation time (first observation of running milt in each individual) in L Feb–May, L Feb–June and L Continuous was advanced by 10, 7 and 5 weeks, compared to SNP. A switch from long to short day early in the reproductive cycle (L Feb–May and L Feb–June) apparently resulted in stronger synchronization of both ovulation and spermiation. Ovulation in L Feb–May and L Feb–June occurred over 3 weeks (L Feb–May) and 8 weeks (L Feb–June), as compared to 10 weeks in the SNP group, whereas all males (except one individual) began spermiating over a period of 3 weeks (L Feb–June), or less (L Feb–May), as compared to 7 weeks in the SNP group. Lack of a short day stimulus (L Continuous), on the other hand, resulted in larger variation in the timing of final maturation, with ovulation and spermiation being spread over 15 weeks. Low egg survival in L Feb–May (17% versus 60% and 97% for L Continuous and SNP) indicate that a long day signal of 10 weeks early in the reproductive cycle may be too short to ensure good egg and sperm quality. Photoperiod manipulation did not affect the proportion of maturing fish.

EM 알고리듬을 이용한 단일염기변이 (SNP;SINGLE NUCLEOTIDE POLYMORPHISM)군의 일배체형 (HAPLOTYPE) 비율 추정

복합성유전질환 연구에 있어서 단일염기변이를 이용한 일배체형 분석은 개별적인 단일염기변이 분석에 비하여 비용 및 효율 면에서 훨씬 유용하며, 생물학적으로도 기능적 중요성을 갖는 것으로 평가되고 있다. 그러나 일반적인 유전형분석방법을 이용한 단일염기변이군 자료는 이배체형(diploid)으로서 위상(phase)을 확인할 수 없으므로 일배체형 비율을 예측하기 어렵다. 본 연구에서는 고형종양 환자군과 정상군의 단일염기변이군 이배체형 자료가 주어졌을 때 단일염기변이군 일배체형 비율의 우도함수에 EM알고리듬을 적용하여 각 일배체형의 비율을 추정하였다. 이로부터 단일염기변이간의 연관불균형(linkage disequilibrium)을 분석하여 고형 종양과 연관 가능성이 있는 단일염기변이를 살펴보았다. Haplotype analysis in SNP is very useful for the study of complex genetic disease due to low cost and high efficiency comparing to individual analysis of each SNP, and is functionally important in biological view. But, the gametic phase of haplotypes is usually unknown in SNP group, and it is difficult to predict haplotype proportions. In this study, haplotype proportions were estimated using EM algorithm from diploid data of SNP group in solid tumor group and normal group. From these results, linkage disequilibrium among SNPs was analyzed.

<b>Effect of spinally superfused SN</b><b><sub>,</sub></b><b>P on the WDR neuron s </b><b>activity in the rabbit s spinal cord </b>

Spinal mechanisms of hyperalgesia is believed to be caused by a series of actions, including activation of NMDA receptors with an increase in intracellular NO in the second-order neurons of the spinal cord dorsal horn, activation of guanyl cyclase (GC) and the subsequent activation of protein kinase, and gene expression. We investigated the influence of NO increase on NMDA receptors and the subsequent involvement of GC. Exposed rabbit spinal cords were irrigated with SNP, as an NO source, and WDR neuron activity was measured electrophysiologically by an extracellular microelectrode. Spontaneous and pinching-induced activities of the WDR neurons were also measured after irrigating with SNP only, a mixture of SNP and MK801 (NMDA recep tor antagonist), a mixture of SNP and MB (GC inhibitor), or a mixture of SNP and HB (NO scavenger). In the SNP group the numbers of both spontaneous and pinching-induced activities increased, and the increase in neuronal activity after pinching lasted for approximately 2 hours. There were no significant differ ences in the number of either spontaneous or induced activities after administrating the mixture of SNP and MK801 compared to the SNP group.However, the duration of increased activity decreased significantly. In the SNP/MB and SNP/HB groups there was a significant reduction in both spontaneous and induced activities compared to the SNP group. From the data above hyperalgesia caused by SNP could be related to NO. Because there was no significant difference in neuronal activity between the SNP group and the mixture of SNP and MK801 group, MK801 seemed not to inhibit hyperalgesia easily once it was induced in the spinal cord dorsal horn. GC activation and cGMP hyperfunction associated with increased NO were assumed to participate in hyperalgesia, as the mixture of SNP and MB did not make significant changes in both spontaneous and induced activities.Both spontaneous and induced activities were stayed in the control level after irrigation with SNP and HB, which confirmed that NO played a role in increasing WDR neuron activity. NO delivered from SNP was speculated to continuously increase spontaneous WDR neuron activity, and to accentuate stimuli-induced activity, contributing to central sensitization in the spinal cord.

Nebulization of sodium nitroprusside in lung-lavaged newborn piglets.

The aim of the present study was to test the hypothesis that nebulization of the nitric oxide donor sodium nitroprusside may selectively reduce pulmonary vascular resistance and improve oxygenation in lung-lavaged newborn piglets. Thirteen anesthetized piglets (1-3 d old) were subjected to repeated lung lavages and then randomly assigned to one of the following two groups: 1) an SNP group, which received SNP nebulization, and 2) a saline group, which received saline nebulization. Pulmonary arterial pressure and pulmonary vascular resistance increased significantly after lung lavage, whereas cardiac output decreased significantly in both groups. After SNP nebulization, pulmonary arterial pressure decreased from 32+/-1 to 17+/-1 mm Hg (p < 0.01) and PVR decreased from 255+/-20 to 172+/-15 mm Hg L(-1) min(-1) kg(-1) (p < 0.01). The arterial tension of oxygen concomitantly increased from 9.4+/-4.0 to 17.0+/-3.0 kPa (p < 0.01), and the arterial/alveolar ratio of oxygen tension increased from 0.11+/-0.01 to 0.22+/-0.03 (p < 0.01). Systemic hemodynamics were not modified significantly during nebulization of SNP. On the other hand, all variables were stable during nebulization of saline. These data suggest that SNP nebulization produces a selective pulmonary vasodilatation and improves oxygenation in lung-lavaged newborn piglets.

Abnormal in vivo response to sodium nitroprusside after porcine single lung transplantation.

The chronic increase of pulmonary vascular resistance after lung transplantation is only partly due to an active increase in baseline vasomotor tone, but the nature of the acute pulmonary hypertension after ischemia and reperfusion is not known. We studied the effects of sodium nitroprusside on pulmonary hemodynamics during reperfusion in porcine left lung allotransplants. In twelve pigs (weight: 18 to 24 kg) pulmonary arteries of the native and the transplanted lung were cannulated for right-heart bypass. The total blood flow was 2 L/min. Flow distribution between the lungs was measured at equal mean pulmonary artery pressure, and pulmonary vascular resistance at equal and constant flow-i.e., 1 L/min to each lung. After baseline measurements sodium nitroprusside (1, 3, and 9 microg/kg/min) was administered to six animals (SNP group). The control group (n=6) received an equal amount of the vehicle. After 30 min of discontinuation of the drug infusion, the schedule was repeated. In the transplanted lung, pulmonary vascular resistance decreased in all animals during the first hour of reperfusion. During the second drug infusion pulmonary vascular resistance was significantly lower in the SNP group compared with the control group only at the highest infusion rate of the drug (9 microg/kg/min), which also induced a 44% decrease in systemic vascular resistance. Arterial oxygen tension remained comparable in the two groups throughout the study. Our data suggest that other factors besides active vasoconstriction may contribute to the acute increase of pulmonary vascular resistance after lung transplantation.

Endogenous and exogenous nitric oxide protect against intracoronary thrombosis and reocclusion after thrombolysis.

Nitric oxide (NO), an endothelium-derived relaxing factor, plays an important role in regulating platelet activation. We evaluated the effect of NO in a canine model of intracoronary thrombosis, thrombolysis, and reocclusion. Before thrombosis was induced, 34 anesthetized dogs were treated with a continuous intracoronary infusion of saline (n = 8); NG-nitro-L-arginine (L-NNA, n = 8), an inhibitor of NO synthetase; L-arginine (n = 7), the precursor for NO; or sodium nitroprusside (SNP, n = 11), an NO donor. Ten minutes after the infusion was begun, an electric current of 150 microA was applied to the endothelium of coronary arteries to induce thrombosis. Occlusive thrombi developed in all dogs in the saline group (38 +/- 4 minutes) and the L-NNA group (30 +/- 6 minutes), in 6 of 7 dogs in the L-arginine group (81 +/- 18 minutes), and in 6 of 11 dogs in the SNP group (102 +/- 21 minutes) (P < .01). The time to thrombus was prolonged by L-arginine (P < .05) and SNP (P < .01). After 3 hours of thrombus formation in coronary arteries, tissue plasminogen activator and heparin were administered intravenously. Thrombi were lysed in 4 (of 8) dogs in the saline group (71 +/- 8 minutes), in 4 (of 8) dogs in the L-NNA group (72 +/- 8 minutes), in 4 (of 6) dogs in the L-arginine group (50 +/- 14 minutes), and in 4 (of 6) dogs in the SNP group (49 +/- 11 minutes) (P > .05). After thrombolysis, coronary artery reocclusion developed in all reperfused dogs in the saline group (30 +/- 8 minutes) and in the L-NNA group (48 +/- 12 minutes), in 3 (of 4) reperfused dogs in the L-arginine group (123 +/- 26 minutes), and in 3 (of 4) reperfused dogs in the SNP group (128 +/- 19 minutes) (P < .01). The ex vivo platelet aggregation induced by collagen was inhibited after in vivo treatment with L-arginine or SNP. Increasing NO production or giving an NO donor may inhibit platelet aggregation and delay intracoronary thrombus formation and reocclusion after thrombolysis.

Effects of hypotensive anesthesia with sodium nitroprusside or isoflurane on hemodynamic and metabolic changes.

The hemodynamic and metabolic changes during induced hypotension with isoflurane (isoflurane group) or sodium nitroprusside (SNP group) were observed in twelve mongrel dogs. These hypotensive effects were evaluated at 30 and 60 minutes after the mean arterial blood pressure was lowered to 50% from the control. Hemodynamic changes were evaluated by measuring systemic arterial blood pressure, heart rate, central venous pressure, pulmonary capillary wedge pressure, cardiac output, systemic vascular resistance and pulmonary vascular resistance. Metabolic changes were evaluated by measuring serum lactate and pyruvate, arterio-venous oxygen content difference and oxygen extraction rate. We also compared the ventilatory effect of hypotensive anesthesia by blood gas analysis. The results were as follows: 1. Isoflurane inhalation 2-4% or SNP infusion 10-20 micrograms/kg/min was required to reduce the mean arterial pressure to 50% of the control. 2. Heart rate was decreased slightly in the isoflurane group but significantly decreased in the SNP group. 3. There were no significant changes in central venous pressure and pulmonary capillary wedge pressure in either group. 4. Cardiac output was reduced in both groups but was more severe in the isoflurane group. 5. Systemic vascular resistance was decreased by 36% in the isoflurane group and 47% in the SNP group. 6. Acidosis was apparent and did not recover to the control until 30 minutes after recovery in the SNP group. 7. Arterio-venous oxygen difference was increased during hypotension in the isoflurane group probably due to decreased cardiac output. 8. The lactate/pyruvate ratio increased slightly in the SNP group.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of isollurane with sodium nitroprusside for controlling hypertension during thoracic aortic cross-clamping

The aims of this randomized study were (1) to determine if isoflurane is effective in controlling blood pressure during thoracic aortic cross-clamping, and (2) to compare its effects on hemodynamics and oxygen transport to those of sodium nitroprusside. Sodium nitroprusside (SNP group, n = 10) or isoflurane (ISO group, n = 10) was started 2 minutes before cross-clamping and was adjusted to maintain systolic arterial pressure as near as possible to preinduction values. The duration of thoracic aortic cross-clamping was 26 ± 4 minutes in the SNP group and 30 ± 4 minutes in the ISO group. Administration of isoflurane and sodium nitroprusside was stopped 2 minutes before unclamping. The same anesthetic technique using fentanyl, 6 μg/kg, flunitrazepsm, 0.02 mg/kg, pancuronium, 0.1 mg/kg, and 50% N 2O was used for all patients. At the time of clamping, either isoflurane (maximal expired concentration, 2.6% ± 0.3%) or sodium nitroprusside (cumulative dose, 11.1 ± 1.0 mg) was effective in maintaining the systolic blood pressure below 160 mm Hg, whereas the pulmonary capillary wedge pressure did not change. However, only SNP was able to bring the arterial pressure above the cross-clamp back to postinduction levels. During clamping, stroke index values were similar in both groups, but cardiac index increased only in patients receiving SNP. In both groups, at clamping and unclamping, PvO 2 was higher than postinduction values, indicating that throughout the study the oxygen needs of the perfused area were adequately met. There was no evidence of acute left ventricular decompensation because pulmonary capillary wedge pressures did not abruptly increase, nor did pulmonary edema occur. It is concluded that isoflurane added to fentanyl anesthesia is acceptable for thoracic aortic aneurysm surgery because it allows safe and effective control of hypertension during clamping without compromising hemodynamics and oxygen transport.

Systolic Pressure Variation Is Greater during Hemorrhage than during Sodium Nitroprusside-Induced Hypotension in Ventilated Dogs

The systolic pressure variation (SPV), which is the difference between the maximal and minimal values of the systolic blood pressure (SBP) after one positive-pressure breath, was studied in ventilated dogs subjected to hypotension. Mean arterial pressure was decreased to 50 mm Hg for 30 minutes either by hemorrhage (HEM, n = 7) or by continuous infusion of sodium nitroprusside (SNP, n = 7). During HEM-induced hypotension the cardiac output was significantly lower and systemic vascular resistance higher compared with that in the SNP group. The systemic, central venous, pulmonary capillary wedge pressures, and heart rates, were similar in the two groups. Analysis of the respiratory changes in the arterial pressure waveform enabled differentiation between the two groups. The SPV during hypotension was 15.7 +/- 6.7 mm Hg in the HEM group, compared with 9.1 +/- 2.0 mm Hg in the SNP group (P less than 0.02). The delta down, which is the measure of decrease of SBP after a mechanical breath, was 20.3 +/- 8.4 and 10.1 +/- 3.8 mm Hg in the HEM and SNP groups, respectively, during hypotension (P less than 0.02). It is concluded that increases in the SPV and the delta down are characteristic of a hypotensive state due to a predominant decrease in preload. They are thus more important during absolute hypovolemia than during deliberate hypotension.

Cerebral blood flow responses to hypocapnia during hypotension.

Cerebral vascular responses to hypocapnia during hypotension to a mean arterial blood pressure (MAP) = 50 mm Hg induced with sodium nitroprusside (SNP, n = 12) or trimethaphan (TMP, n = 12) were examined in dogs. Cerebral vascular resistance (CVR) and cerebral blood flow (CBF) at PaCO2 = 40 mm Hg, and PaCO2 = 20 mm Hg were examined first at normal MAP then at hypotension in six dogs in the SNP group and six dogs in the TMP group. In both the SNP group and the TMP group, CO2 responsiveness, as indicated by increased CVR and decreased CBF, was intact at normal MAP, but absent during hypotension. In the remaining 6 of 12 dogs in the SNP group and 6 of 12 dogs in the TMP group, CO2 responsiveness at MAP = 50 mm Hg was examined without prior determination of CO2 responsiveness at normal MAP. These additional studies were performed to rule out the possibility that absent CO2 responsiveness during hypotension in the initial groups resulted from (1) physiologic deterioration of the preparation with time, or (2) adaptation of brain extracellular fluid pH to a preceding period of hypocapnia. Again, during both SNP- or TMP-induced hypotension CO2 responsiveness was absent.

Modification of Bovine Pancreatic Ribonuclease A with 4-Sulfonyloxy-2-nitrofluorobenzene: Isolation and Identification of Modified Proteins

Abstract The inactivation of RNase A that accompanies dinitrophenylation at pH 8 is in major part due to substitution at lysine-41. The amino group of this lysine residue has been postulated to be part of, or close to, the site responsible for binding the phosphate moiety in the substrate. In elaboration of this concept, the consequences that derive from the replacement of 1-fluoro-2,4-dinitrobenzene (FDNB) by a negatively charged reagent with similar chemical and steric properties have been explored. This reagent, 4-sulfonyloxy-2-nitro-fluorobenzene (SNFB), inactivates RNase A at pH 8 by substitution at position 41. It also attacks the enzyme at the α-amino group to produce 1-α-sulfonyloxynitrophenyl (SNP)-RNase A, a fully active derivative. Dinitrophenylation at lysine-41 occurs about 7 times faster than at the α-amino group. By contrast both of these amino groups are about equally reactive toward SNFB at pH 8, an observation interpreted in terms of an oriented approach of the reagent in a configuration unfavorable for reaction at lysine-41. Both 1-α- and 41-SNP-RNase A have been isolated and the locations of the substituents identified by degradative procedures similar to those used in previous studies of the corresponding dinitrophenyl-derivatives. These monosubstitution products and 1-α,41-e-bis-SNP-RNase A, which was also isolated and identified, constitute the principal products formed in the initial stages of the reaction. In contrast to the behavior with FDNB, subsequent reaction at position 7 either does not take place or is strongly suppressed with SNFB. This behavior indicates that 41-dinitrophenyl- and 41-SNP-RNase A may exist in different conformations, with the difference ascribable to the affinity of the sulfonate moiety in the SNP group for the phosphate-binding site. SNFB has a number of advantages over FDNB as a reagent for the modification of RNase A. These include a higher specificity for amino groups, convenient solubility, and the fact that spectra of the reagent and the derivatives that it forms do not overlap as much as with FDNB. The disadvantage of lowered reactivity toward amino groups is offset by the feasibility of studies at relatively high pH values.