Left ventricular end diastolic pressure for detection of intracoronary ergonovine-induced myocardial ischemia.

BACKGROUND: Recent consensus on variant angina defines significant spasm as total or subtotal occlusion of a coronary artery. However, the clinical significance of "less-than-subtotal" spasm needs to be reappraised, especially if the coronary spasm is combined with chest pain. Therefore, we evaluated the feasibility of left ventricular end diastolic pressure (LVEDP) as a tool to detect myocardial ischemia during ergonovine provocation testing. METHODS: After achieving two access sites, 29 patients underwent successful LVEDP monitoring using 5-Fr pigtail catheters during ergonovine provocation tests. Patients were divided into two groups based on the occurrence of anginal symptoms. RESULTS: Of the 29 patients, 16 (55 %) patients had anginal symptoms. LVEDP was significantly increased in the symptomatic group compared with the nonsymptomatic group (∆LVEDP 5.6 ± 4.2 vs. 1.2 ± 2.0 mmHg, p = 0.002). However, of the 16 patients with anginal symptoms, positive provocation test results were confirmed in only six patients (38 %) as per the traditional standard (> 90 % inducible spasm of the epicardial coronary artery). CONCLUSION: Compared with the traditional standard, LVEDP may have advantages in terms of elucidating anginal symptoms in patients suspected of having coronary vasospasm when performing ergonovine provocation tests.

Identification of a novel HLA-B*40 variant allele, B*40:301, by sequence-based typing.

The new allele, HLA-B*40:301 differs from B*40:01:02 by one nucleotide substitution at codon 239 (AGA → AAA).

GWAS of DNA methylation variation within imprinting control regions suggests parent-of-origin association.

Imprinting control regions (ICRs) play a fundamental role in establishing and maintaining the non-random monoallelic expression of certain genes, via common regulatory elements such as non-coding RNAs and differentially methylated regions (DMRs) of DNA. We recently surveyed DNA methylation levels within four ICRs (H19-ICR, IGF2-DMR, KvDMR, and NESPAS-ICR) in whole-blood genomic DNA from 128 monozygotic (MZ) and 128 dizygotic (DZ) human twin pairs. Our analyses revealed high individual variation and intra-domain covariation in methylation levels across CpGs and emphasized the interaction between epigenetic variation and the underlying genetic sequence in a parent-of-origin fashion. Here, we extend our analysis to conduct two genome-wide screenings of single nucleotide polymorphisms (SNPs) underlying either intra-domain covariation or parent-of-origin-dependent association with methylation status at individual CpG sites located within ICRs. Although genome-wide significance was not surpassed due to sample size limitations, the most significantly associated SNPs found through multiple-trait genome-wide association (MQFAM) included the previously described rs10732516, which is located in the vicinity of the H19-ICR. Similarly, we identified an association between rs965808 and methylation status within the NESPAS-ICR. This SNP is positioned within an intronic region of the overlapping genes GNAS and GNAS-AS1, which are imprinted genes regulated by the NESPAS-ICR. Sixteen other SNPs located in regions apart from the analyzed regions displayed suggestive association with intra-domain methylation. Additionally, we identified 13 SNPs displaying parent-of-origin association with individual methylation sites through family-based association testing. In this exploratory study, we show the value and feasibility of using alternative GWAS approaches in the study of the interaction between epigenetic state and genetic sequence within imprinting regulatory domains. Despite the relatively small sample size, we identified a number of SNPs displaying suggestive association either in a domain-wide or in a parent-of-origin fashion. Nevertheless, these associations will require future experimental validation or replication in larger and independent samples.

Resistance to diet-induced hypercholesterolemia and gallstone formation in ACAT2-deficient mice.

The importance of cholesterol ester synthesis by acyl CoA:cholesterol acyltransferase (ACAT) enzymes in intestinal and hepatic cholesterol metabolism has been unclear. We now demonstrate that ACAT2 is the major ACAT in mouse small intestine and liver, and suggest that ACAT2 deficiency has profound effects on cholesterol metabolism in mice fed a cholesterol-rich diet, including complete resistance to diet-induced hypercholesterolemia and cholesterol gallstone formation. The underlying mechanism involves the lack of cholesterol ester synthesis in the intestine and a resultant reduced capacity to absorb cholesterol. Our results indicate that ACAT2 has an important role in the response to dietary cholesterol, and suggest that ACAT2 inhibition may be a useful strategy for treating hypercholesterolemia or cholesterol gallstones.

Infant CD4 C868T polymorphism is associated with increased human immunodeficiency virus (HIV-1) acquisition.

The C868T single nucleotide polymorphism (SNP) in the CD4 receptor encodes an amino acid change that could alter its structure and influence human immunodeficiency virus (HIV-1) infection risk. HIV-1-infected pregnant women in Nairobi were followed with their infants for 1 year postpartum. Among 131 infants, those with the 868T allele were more likely than wild-type infants to acquire HIV-1 overall [hazard ratio (HR) = 1.92, 95% confidence interval (CI) 1.05, 3.50, P = 0.03; adjusted HR = 2.03, 95% CI 1.03, 3.98, P = 0.04], after adjusting for maternal viral load. This SNP (an allele frequency of approximately 15% in our cohort) was associated with increased susceptibility to mother-to-child HIV-1 transmission, consistent with a previous study on this polymorphism among Nairobi sex workers.

Comparison of the pathogenicity in three different Korean canine parvovirus 2 (CPV-2) isolates.

Canine parvovirus type 2 (CPV-2) is a major pathogen inducing acute hemorrhagic gastroenteritis in dogs. Despite the identification of numerous CPV-2 variants (from CPV-2a to CPV-2c), the pathogenic differences among the CPV-2 variants in dogs have not been evaluated. The aim of this study was to compare the pathogenicity of CPV-2 variants (CPV-2a-I, CPV-2a-V and CPV-2b) isolated mainly from Korea. We evaluated the pathogenicity of three different CPV-2 variants, by performing clinical, hematological, serological and histopathological examinations after experimentally inoculating three types of CPV-2 variants into young puppies. We found that the overall pathogenicity of the CPV-2a variants (CPV-2a-I and 2a-V) was severer compared to the CPV-2b variant. In addition, there was no significant difference in pathogenicity between the two CPV-2a variants. Our findings indicate that there are differences in the pathogenicity of CPV-2 variants in dogs, which may be useful to understand the different pathobiology of the CPV-2 variants.

Relationship between foot strike pattern, running speed, and footwear condition in recreational distance runners.

Compared to competitive runners, recreational runners appear to be more prone to injuries, which have been associated with foot strike patterns. Surprisingly, only few studies had examined the foot strike patterns outside laboratories. Therefore, this study compared the foot strike patterns in recreational runners at outdoor tracks with previously reported data. We also investigated the relationship between foot strike pattern, speed, and footwear in this cohort. Among 434 recreational runners analysed, 89.6% of them landed with rearfoot strike (RFS). Only 6.9 and 3.5% landed with midfoot and forefoot, respectively. A significant shift towards non-RFS was observed in our cohort, when compared with previously reported data. When speed increased by 1 m/s, the odds of having forefoot strike and midfoot strike relative to RFS increased by 2.3 times and 2.6 times, respectively. Runners were 9.2 times more likely to run with a forefoot strike in minimalists compared to regular running shoes, although 70% of runners in minimalists continued to use a RFS. These findings suggest that foot strike pattern may differ across running conditions and runners should consider these factors in order to mitigate potential injury.

Ginsenoside Re attenuate beta-amyloid and serum-free induced neurotoxicity in PC12 cells.

AIM: To study the effect of ginsenoside Re on PC12 cell damage induced by serum deprivation and beta-amyloid peptide. METHODS: PC 12 cell survival was measured by MTT and lactate dehydrogenase (LDH) assay. Results Serum-free medium and beta-amyloid peptide (10-100 microM) induced cytotoxicity in PC 12 cells. Ginsenoside Re (0.1-100 microM) attenuated the cytotoxic effects of serum-free medium and beta-amyloid peptide (50 microM) in a concentration-dependent manner. CONCLUSION: Ginsenoside Re prevented PC 12 cells from lesion induced by serum-free medium and beta-amyloid peptide.

Expression of the P2Y1 nucleotide receptor in chick muscle: its functional role in the regulation of acetylcholinesterase and acetylcholine receptor.

In vertebrate neuromuscular junctions, ATP is stored at the motor nerve terminals and is co-released with acetylcholine during neural stimulation. Here, we provide several lines of evidence that the synaptic ATP can act as a synapse-organizing factor to induce the expression of acetylcholinesterase (AChE) and acetylcholine receptor (AChR) in muscles, mediated by a metabotropic ATP receptor subtype, the P2Y(1) receptor. The activation of the P2Y(1) receptor by adenine nucleotides stimulated the accumulation of inositol phosphates and intracellular Ca(2+) mobilization in cultured chick myotubes. P2Y(1) receptor mRNA in chicken muscle is very abundant before hatching and again increases in the adult. The P2Y(1) receptor protein is shown to be restricted to the neuromuscular junctions and colocalized with AChRs in adult muscle (chicken, Xenopus, and rat) but not in the chick embryo. In chicks after hatching, this P2Y(1) localization develops over approximately 3 weeks. Denervation or crush of the motor nerve (in chicken or rat) caused up to 90% decrease in the muscle P2Y(1) transcript, which was restored on regeneration, whereas the AChR mRNA greatly increased. Last, mRNAs encoding the AChE catalytic subunit and the AChR alpha-subunit were induced when the P2Y(1) receptors were activated by specific agonists or by overexpression of P2Y(1) receptors in cultured myotubes; those agonists likewise induced the activity in the myotubes of promoter-reporter gene constructs for those subunits, actions that were blocked by a P2Y(1)-specific antagonist. These results provide evidence for a novel function of ATP in regulating the gene expression of those two postsynaptic effectors.

Canine pancreatic-specific lipase concentrations in dogs with heart failure and chronic mitral valvular insufficiency.

BACKGROUND: Chronic mitral valvular insufficiency (CMVI) in dogs is very common and might cause clinical signs of congestion and poor tissue perfusion. HYPOTHESIS: Poor tissue perfusion from CMVI causes pancreatitis in dogs, as indicated by serum pancreatic lipase concentrations. ANIMALS: Sixty-two client-owned dogs consisting of 40 dogs with different stages of heart failure from CMVI and 22 age-matched healthy dogs, based on full cardiac exam and routine laboratory tests. METHODS: Prospective, controlled, observational study. Serum canine pancreatic lipase immunoreactivity (cPLI) concentrations were determined by quantitative cPLI test in healthy and CMVI groups. RESULTS: Serum cPLI concentrations were 54.0 µg/L (IQR: 38.0-78.8 µg/L) in control, 55.0 µg/L (IQR: 38.3-88.8 µg/L) in ISACHC I, 115.0 µg/L (IQR: 45.0-179.0 µg/L) in ISACHC II and 223.0 µg/L (IQR: 119.5-817.5 µg/L) in ISACHC III. Close correlation to serum cPLI concentration was found in the left atrial to aorta (LA/Ao) ratio (r = 0.597; P = .000) and the severity of heart failure (r = 0.530; P = .000). CONCLUSIONS AND CLINICAL IMPORTANCE: This study found CMVI is associated with pancreatic injury in congestive heart failure caused by CMVI. Therefore, periodic monitoring on cPLI could be useful in monitoring dogs in heart failure.

Regenerative signals for intestinal epithelial organoid units transplanted on biodegradable polymer scaffolds for tissue engineering of small intestine.

BACKGROUND: Our laboratory is investigating the tissue engineering of small intestine using intestinal epithelial organoid units seeded onto highly porous biodegradable polymer tubes. This study investigated methods of stimulation for optimizing neointestinal regeneration. METHODS: Intestinal epithelial organoid units harvested from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes and implanted into the omentum of adult Lewis rats in the following groups: (1) the control group (group C), implantation alone (n=9); (2) the small bowel resection (SBr) group, after 75% SBr (n=9); (3) the portacaval shunt (PCS) group, after PCS (n=8); and (4) the partial hepatectomy (PH) group, after 75% PH (n=8). Neointestinal cyst size was recorded using ultrasonography. Constructs were harvested at 10 weeks and were examined using histology. Morphometric analysis of the neomucosa was obtained using a computer image analysis program (NIH Image, version 1.59). RESULTS: Cyst development was noted in all animals. Cyst lengths and diameters were significantly larger in the SBr group at 7 and 10 weeks compared with the other three groups (P<0.05; analysis of variance [ANOVA], Fisher's protected least significant difference). Histology revealed a well-vascularized tissue with a neomucosa lining the lumen with invaginations resembling crypt-villus structures. Morphometric analysis demonstrated a significantly greater villus number, height, area, and mucosal surface in the SBr group compared with the other three groups and a significantly greater crypt number and area in the PCS group compared with group C (P<0.05; ANOVA, Fisher's protected least significant difference). CONCLUSIONS: Intestinal epithelial organoid units transplanted on porous biodegradable polymer tubes can successfully vascularize, survive, and regenerate into complex tissue resembling small intestine. SBr and, to a lesser extent, PCS provide significant regenerative stimuli for the morphogenesis and differentiation of tissue-engineered small intestine.

Successful anastomosis between tissue-engineered intestine and native small bowel.

BACKGROUND: Previous work from this laboratory has shown that isolated intestinal epithelial organoid units on porous biodegradable polymer scaffolds formed vascularized cysts lined by a neomucosa. The purpose of this study was to demonstrate anastomosis between tissue-engineered intestine and the native small bowel and to observe the effect of this anastomosis on cyst growth. METHODS: Intestinal epithelial organoid units from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes made of polyglycolic acid, and they were implanted into the omentum of adult male Lewis rats. Three weeks after implantation, the unit-polymer constructs were anastomosed in a side-to-side fashion to the native jejunum in 20 rats (group 1). The other 18 rats were closed without anastomosis (group 2). All 38 tissue-engineered constructs were harvested 10 weeks after implantation. Four rats underwent upper gastrointestinal (GI) study before they were killed. RESULTS: The rats in group 1 increased their body weights equal to those in group 2, and there was no statistically significant difference between the two groups. Upper GI examinations revealed no evidence of either bowel stenosis or obstruction at the anastomotic site. Grossly, the patency of the anastomosis was 90% and the lumen of the cyst was visualized by the upper GI study. At the second operation, there was no significant difference in the size of the cysts in either group: however, at the time the rats were killed, the length of the cysts in group 1 was significantly longer than that in group 2 (P<0.05 using Mann-Whitney U test). Histological examination showed that cysts after anastomosis were lined by a neomucosa in continuity to native small bowel across the anastomotic site and also demonstrated crypt-villus structures. Morphometric study demonstrated that cysts in group 1 had significantly greater villus number, height, and surface length than did those in group 2. CONCLUSIONS: Anastomosis between tissue-engineered intestine and native small bowel resulted in no complications after the operation, kept a high patency rate, and maintained mucosal continuity between the tissue-engineered intestine and native small bowel. Furthermore, anastomosis had a positive effect on cyst size and development of the mucosa in the tissue-engineered intestine.

HIV type 1 Gag and nucleocapsid proteins: cytoskeletal localization and effects on cell motility.

Cell motility is likely to play a pivotal role in HIV infection by promoting the dissemination of infected cells. On the basis of observations indicating an interaction between HIV-1 Gag and target cell filamentous actin, we hypothesized that these interactions would promote cell motility of HIV-infected cells. Indeed, we have found that HIV-1 infection enhances the chemotactic response of macrophages. To specifically investigate the significance of the interactions between Gag and cellular actin, we transfected NIH 3T3 fibroblasts and HeLa cells with a construct that permits the expression of HIV-1 Gag in the absence of any other viral protein. Fractionation experiments showed that Gag was present in cytoskeletal fraction containing long actin filaments and in a high-speed postcytoskeletal fraction with short actin filaments. We have also localized HIV-1 Gag to the lamellipodia of chemoattractant-stimulated cells. Significantly, the motility of Gag-expressing cells was enhanced in chemotaxis assays. In vitro mutagenesis experiments showed that HIV-1 Gag binds filamentous actin through the nucleocapsid domain (NC). An NC-green fluorescent protein fusion had the same cellular distribution as the complete protein, and its expression increased cell motility. These data suggest that interactions between HIV-1 Gag and actin in infected cells enhance cell motility. Ultimately this enhanced motility of infected cells could promote the dissemination of virus into the brain and other tissues.

The wound healing response after laser in situ keratomileusis and photorefractive keratectomy: elusive control of biological variability and effect on custom laser vision correction.

Biological diversity in the wound healing response is thought to be a major factor limiting the predictability of the outcome of refractive surgical procedures such as laser in situ keratomileusis and photorefractive keratectomy. Corneal wound healing is critical to the success of topography-linked or wave front-linked excimer laser ablation to optimize visual performance. This is because of the importance of retaining subtle features of custom ablation and the tendency of epithelial hyperplasia and stromal remodeling to obscure these features following either procedure. The corneal wound healing response is exceedingly complex. Keratocyte apoptosis, which occurs in response to epithelial injury, is the earliest observable event in the wound healing cascades and is therefore an excellent target for pharmacological intervention. Alterations of surgical technique can be designed to limit keratocyte apoptosis and the subsequent events in corneal wound healing. Abnormalities of the cascades could contribute to the pathogenesis of corneal diseases. For example, recent data have suggested that perturbation of the keratocyte apoptosis/mitosis balance could underlie the development of keratoconus in a proportion of patients.

Primary orbital Ewing sarcoma in a middle-aged woman.

A 43-year-old woman had unilateral exophthalmos caused by primary orbital Ewing sarcoma. Specialized immunohistochemical stains, primarily MIC-2 (CD99), aided in the diagnosis of Ewing sarcoma. Twenty-two months after radiotherapy and multiagent chemotherapy, the patient remained tumor free. To our knowledge, this is the first reported case of orbital Ewing sarcoma to present in an adult beyond the fourth decade of life.

The cAMP-dependent protein kinase mediates the expression of AChE in chick myotubes.

Calcitonin gene-related peptide (CGRP), a neuropeptide synthesized by motor neurons, stimulates the expression of AChR and AChE at the vertebrate neuromuscular junctions. The signaling mechanism of CGRP-induced AChE expression in muscle was determined both in vitro and in vivo. In cultured chick myotubes, the intracellular cAMP-dependent protein kinase (PKA) activity increased to approximately 2-fold after the application of CGRP or PKA activators; the induction was blocked by PKA inhibitors. in vivo transfection analysis on chick gastrocnemius muscles showed that the transfection of cDNA encoding constitutively active mutant Galphas increased the expression of AChE mRNA and protein to approximately 2-fold, while the constitutively active mutant Galphai cDNA transfection showed an opposite effect. The induced catalytic subunit of AChE at approximately 105 kDa was determined by specific antibody. These findings indicate that the CGRP-induced AChE expression in chick muscle is mediated by a PKA-dependent pathway.

Female surgeons in the 1990s. Academic role models.

As part of a larger survey of the membership of the Association of Women Surgeons, data were collected to characterize the participation of women in academic surgery and surgical education. Of the 1500 members, 676 (45%) responded, and 318 of these respondents held a faculty appointment. Two hundred thirty-nine of the respondents' practices were based in a university or university-affiliated hospital. This sample was biased toward more academically motivated, upwardly mobile surgeons. Two hundred thirty-six of the respondents believed policies relating to tenure are unfair to women. Four hundred fifty-three respondents reported having role models at some point in their career, half of whom were men. However, only 204 still had access to role models or mentors at the time of the survey. Six hundred thirty respondents believed that female medical students need successful female surgeons as role models.

Effects of food on the bioavailability of CGS 16617, an angiotensin-converting enzyme inhibitor, in healthy subjects.

CGS 16617, a direct-acting angiotensin-converting-enzyme inhibitor, was administered as a single dose of 20 mg in aqueous solution to 12 healthy male volunteers on two occasions in a randomized, cross-over design study. On one occasion, the dose was administered after an overnight fast; on the other occasion, it was administered after subjects ate a standard breakfast. Administration of CGS 16617 after food was associated with statistically significant decreases in peak plasma concentrations (58%) and areas under the plasma concentration-time curves (23%) compared with drug administration in the fasted state. Also, the time to peak plasma concentration was increased (57%) in a statistically significant manner when CGS 16617 was administered after food. Thus, the ingestion of food decreased both the rate and extent of absorption of this drug, but the mechanism of the interaction is unknown at present.

Pharmacodynamic dependent disposition of the angiotensin converting enzyme inhibitor, libenzapril.

Libenzapril, an angiotensin converting enzyme inhibitor, was administered to healthy male volunteers in a randomized, two-phase pharmacokinetic study. One phase compared the pharmacokinetics of a 4 mg intravenous infusion and 20 mg oral solution, and the other phase provided two additional intravenous infusions of 1.7 and 12 mg for comparison. The intravenous model-independent pharmacokinetic parameters MRTiv, Vss, CL, and CLr all exhibited dose dependence. The concentration dependent renal clearance was maximal at 83 mL/min and minimal at 32 mL/min following intravenous administration. The mechanism of libenzapril's self-inducible clearance appears to have a pharmacodynamic basis. The absolute bioavailability was estimated at less than 10% and the renal clearance following oral administration exhibited additional route dependency.

Inhibition of angiotensin-converting enzyme with libenzapril in normotensive males.

The effect of intravenous (i.v.) libenzapril was studied in six healthy males by administering i.v. angiotensin I (AI) administered in stepwise increments of 20 ng/kg/5 min until the subjects' systolic blood pressure (SBP) had increased 20-30 mm Hg above baseline. The mean baseline infusion of 63 ng/kg/5 min resulted in a significant (P < 0.05) increase in the ratio of AII to AI plasma levels from 0.52 +/- 0.46 to 7.92 +/- 4.48 and a SBP increase of 120 +/- 7.1 to 147 +/- 5.6. Within 15 minutes of starting the 1-mg infusion of libenzapril over 1.5 hours, the AII/AI ratio decreased to baseline values, and the SBP had returned to baseline in 1 hour. Repeat AI challenges at 3.5 and 5 hours postdose did not increase SBP significantly. Even the 6.5-hour challenge demonstrated only a slight increase in SBP, with an AII/AI ratio of 0.26. At 24 hours, SBP was only 40% of the baseline response, demonstrating that libenzapril is a potent long-acting ACE inhibitor.