Comparison of conventional methods with commercially available topical hemostat surgical snow (oxidized cellulose) for achieving hemostasis in canine model of partial splenectomy.

Spleen is highly vascularized organ and bleeding control during partial splenectomy is a big challenge. In this study conventional methods of electrocautery, absorbable suturing and advance methods of topical hemostat Surgicel® were compared to control bleeding during partial splenec- tomy. Twelve healthy dogs (n=4) were divided in A, B and C groups. After partial splenectomy Surgicel®, electrocautery and absorbable horizontal mattress sutures were used to control hemor- rhages in group A, B and C respectively. Bleeding time and loss of blood volume was evaluated during surgery. In addition, blood samples were taken on day 0 pre-surgery and on days 3, 10 and 17 post-surgery to evaluate changes in biochemical parameters after the application of dif- ferent hemostatic techniques. Ultrasonography was also performed at alternative days to check any gross changes in the spleen. Dogs in group A showed minimum bleeding time and loss of blood volume as compared to group B and C. Drop in red blood cells count was compared be- tween group A, B and C showing significant change (p≤0.05) at day 3, 10 and 17, while a sig- nificant decline in hemoglobin was found in group C followed by groups B and A at 3rd and 10th day. There was no difference between platelet counts in various groups. Ultrasonography showed no significant changes in the spleen parenchyma. It was concluded that Surgicel® was an effective material for controlling hemorrhage in veterinary patients.

Lead Extraction Imaging.

Lead extraction procedures have a low but real risk of major complications, such as superior vena cava tear and cardiac tamponade. Complications during lead removal are commonly related to lead binding sites, lead malposition, and lead perforation. Lead extraction imaging may indicate lead vascular binding sites, lead position, and perforation. Several imaging modalities are available, including chest radiograph, cardiac computed tomography, and echocardiography. The information provided by various imaging modalities will help assess the challenges of each lead extraction procedure and allows for better preprocedure planning.

Small molecule targeting the Rac1-NOX2 interaction prevents collagen-related peptide and thrombin-induced reactive oxygen species generation and platelet activation.

Essentials Reactive oxygen species (ROS) generation by NOX2 plays a critical role in platelet activation. Rac1 regulation of NOX2 is important for ROS generation. Small molecule inhibitor of the Rac1-p67phox interaction prevents platelet activation. Pharmacologic targeting of Rac1-NOX2 axis can be a viable approach for antithrombotic therapy. SUMMARY: Background Platelets from patients with X-linked chronic granulomatous disease or mice deficient in nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidase isoform NOX2 exhibit diminished reactive oxygen species (ROS) generation and platelet activation. Binding of Rac1 GTPase to p67phox plays a critical role in NOX2 activation by facilitating the assembly of the NOX2 enzyme complex. Objective We tested the hypothesis that Phox-I, a rationally designed small molecule inhibitor of Rac-p67phox interaction, may serve as an antithrombosis agent by suppressing ROS production and platelet activation. Results Collagen-related peptide (CRP) induced ROS generation in a time-dependent manner. Platelets from Rac1-/- mice or human platelets treated with NSC23766, a specific Rac inhibitor, produced significantly less ROS in response to CRP. Treatment of platelets with Phox-I inhibited diverse CRP-induced responses, including: (i) ROS generation; (ii) release of P-selectin; (iii) secretion of ATP; (iv) platelet aggregation; and (v) phosphorylation of Akt. Similarly, incubation of platelets with Phox-I inhibited thrombin-induced: (i) secretion of ATP; (ii) platelet aggregation; (iii) rise in cytosolic calcium; and (iv) phosphorylation of Akt. In mouse models, intraperitoneal administration of Phox-I inhibited: (i) collagen-induced platelet aggregation without affecting the tail bleeding time and (ii) in vivo platelet adhesion/accumulation at the laser injury sites on the saphenous vein without affecting the time for complete cessation of blood loss. Conclusions Small molecule targeting of the Rac1-p67phox interaction may present an antithrombosis regimen by preventing GPVI- and non-GPVI-mediated NOX2 activation, ROS generation and platelet function without affecting the bleeding time.

The effect of calving in the summer on the hepatic transcriptome of Holstein cows during the peripartal period.

The liver is the main metabolic organ coordinating the adaptations that take place during the peripartal period of dairy cows. A successful transition into lactation, rather than management practices alone, depends on environmental factors such as temperature, season of parturition, and photoperiod. Therefore, we analyzed the effect of calving season on the hepatic transcriptome of dairy cows during the transition period. A total of 12 Holstein dairy cows were assigned into 2 groups based on calving season (6 cows March-April, spring; 6 cows June-July, summer, SU). The RNA was extracted from liver samples obtained at -30, 3, and 35 DIM via percutaneous biopsy and hybridized to the Agilent 44K Bovine (V2) Gene Expression Microarray (Agilent Technologies Inc., Santa Clara, CA). A quantitative PCR on 22 target genes was performed to verify and expand the analyses. A total of 4,307 differentially expressed genes were detected (false discovery rate ≤0.05) in SU compared with spring. Furthermore, 73 unique differentially expressed genes were detected in SU compared with spring cows after applying a fold-change threshold ≥3 and ≤-3. For Kyoto Encyclopedia of Genes and Genomes pathways analysis of differentially expressed genes, we used the dynamic impact approach. Ingenuity Pathway Analysis software was used to analyze upstream transcription regulators and perform gene network analysis. Among metabolic pathways, energy metabolism from lipids, carbohydrates, and amino acids was strongly affected by calving in SU, with a reduced level of fatty acid synthesis, oxidation, re-esterification, and synthesis of lipoproteins, leading to hepatic lipidosis. Glycan-synthesis was downregulated in SU cows probably as a mechanism to counteract the progression of this lipidosis. In contrast, calving in the SU resulted in upregulation of gluconeogenesis but also greater use of glucose as an energy source. Among nonmetabolic pathways, the heat-shock response was obviously activated in SU cows but was also associated with inflammatory and intracellular stress response. Furthermore, data support a recent finding that cows experience endoplasmic reticulum stress around parturition. Transcription regulator analysis revealed how metabolic changes are related to important regulatory mechanisms, including epigenetic modification. The holistic analyses of the liver transcriptome response to calving in the summer at high environmental temperatures underscore how transition cows should be carefully managed during this period, as they experience alterations in liver energy metabolism and inflammatory state increasing susceptibility to health disorders in early postpartum.

Gas extrusion in natural products total synthesis.

The thermodynamic driving force from the release of a gaseous molecule drives a broad range of synthetic transformations. This review focuses on gas expulsion in key reactions within natural products total syntheses, selected from the past two decades. The highlighted examples survey transformations that generate sulfur dioxide, carbon dioxide, carbonyl sulfide, or nitrogen through polar, radical, pericyclic, photochemical, or organometallic mechanisms. Of particular interest are applications wherein the gas extrusion enables formation of a synthetically challenging motif, such as an unusually hindered or strained bond.

Cystoscopic removal of leeches in the lower urinary tract: our experience.

INTRODUCTION: The purpose of this study is to describe the experience of managing leech infestation in lower urinary tract from a tropical country. MATERIALS AND METHODS: Medical records (January 2002 to December 2010) of children with history of leech infestation in the urinary system, admitted in the Department of Pediatric Surgery, Chittagong Medical College & Hospital, Chittagong, Bangladesh were reviewed. All patients underwent saline irrigation through urethral catheter. When saline irrigation failed, cystoscopic examination was done with removal of leeches by flexible graspers. Follow-up was done 2 weeks later. RESULT: The study included 117 patients. Age ranged from 4 to 12 years. Male and female ratio was 3.7:1. All patients had per urethral bleeding. 51 (43.6%) patients had suprapubic pain. All children underwent saline irrigation through urethral catheter. Spontaneous expulsion occurred after saline irrigation in 57 (48.7%) patients. The expelled leeches were alive in 11 cases; dead in 46 patients. Cystoscopic removal of leeches was done in 60 patients (51.3%). In the cystoscopic group, 54 of the removed leeches were dead and 6 were alive. CONCLUSION: Cystoscopic removal can be a useful technique for the removal of leeches from the urinary tract when saline irrigation fails.

Immunohistochemical detection of nerve growth factor and its receptors in the rat periodontal ligament during tooth movement.

OBJECTIVES: Nerve growth factor (NGF) and its receptors, p75 and tyrosine receptor kinase A (Trk A), have been shown to increase following trauma. The aims of this study were to examine changes in the detection of NGF and its receptors during orthodontic tooth movement in the rat, and the effects of anti-NGF on these changes. DESIGN: Orthodontic separators were placed between the right maxillary first and second molars of Sprague-Dawley rats which were equally divided into two groups. Animals from the second group were injected with anti-NGF. The left sides served as controls, and animals were sacrificed at 0, 3, 7 and 14 days. RESULTS: Results of immunohistochemical localisation for p75, Trk A, calcitonin gene-related peptide (CGRP) and NGF showed staining intensity increased at day 3, with a peak at day 7 and decreasing intensity at day 14. Anti-NGF injected animals showed reduced staining at all observation periods. CONCLUSION: Data suggest that orthodontic injury induces NGF production, leading to sprouting and invasion by CGRP-positive nerve fibers and that injection of anti-NGF reduces NGF tissue levels and prevents innervation by CGRP-positive fibers.

Pneumocystis diversity as a phylogeographic tool

Parasites are increasingly used to complement the evolutionary and ecological adaptation history of their hosts. Pneumocystis pathogenic fungi, which are transmitted from host-to-host via an airborne route, have been shown to constitute genuine host markers of evolution. These parasites can also provide valuable information about their host ecology. Here, we suggest that parasites can be used as phylogeographic markers to understand the geographical distribution of intra-specific host genetic variants. To test our hypothesis, we characterised Pneumocystis isolates from wild bats living in different areas. Bats comprise a wide variety of species; some of them are able to migrate. Thus, bat chorology and migration behaviour can be approached using Pneumocystis as phylogeographic markers. In the present work, we find that the genetic polymorphisms of bat-derived Pneumocystis are structured by host chorology. Therefore, Pneumocystis intra-specific genetic diversity may constitute a useful and relevant phylogeographic tool.

Salivary anti-Helicobacter pylori positivity among endoscopy patients with chronic liver disease.

In this study, endoscopy patients with and without chronic liver disease (CLD) were examined and tested for Helicobacter pylori infection by detecting the presence of serum and salivary anti-H. pylori antibody. The validity of these measures was compared with Campylobacter-like organism analysis (gold standard) performed on patients requiring gastric biopsy. Among 114 patients with CLD and 50 without, the commonest endoscopy diagnosis was gastritis (27.2%). Salivary H. pylori positivity was significantly associated with older age. Salivary anti-H. pylori antibody positivity showed low sensitivity (36.6%) and high specificity (75.8%) in CLD patients.

Genetic and pharmacologic evidence that Rac1 GTPase is involved in regulation of platelet secretion and aggregation.

BACKGROUND: Rac1 GTPase, a member of the Ras-related Rho GTPase family, is the major Rac isoform present in platelets and has been shown to be involved in cell actin cytoskeleton reorganization and adhesion. Agonists that induce platelet secretion and aggregation also activate Rac1 GTPase, raising the possibility that Rac1 GTPase may be involved in regulation of platelet function. OBJECTIVES: To rigorously define the role of Rac1 in platelet regulation. METHODS: We have used a dual approach of gene targeting in mice and pharmacologic inhibition of Rac1 by NSC23766, a rationally designed specific small molecule inhibitor, to study the role of Rac1 in platelet function. RESULTS: Platelets from mice as well as human platelets treated with NSC23766 exhibited a significant decrease in: (i) active Rac1 species and phosphorylation of the Rac effector, p21-activated kinase; (ii) expression of P-selectin and secretion of adenosine triphosphate induced by thrombin or U46619; and (iii) aggregation induced by adenosine 5'-diphosphate, collagen, thrombin and U46619, a stable analog of thromboxane A(2). NSC23766 did not alter the cAMP or cGMP levels in platelets. Consistent with the requirement of Rac1 for normal platelet function, the bleeding times in Rac1(-/-) mice or mice given NSC23766 were significantly prolonged. CONCLUSIONS: Our data show that deficiency or inhibition of Rac1 GTPase blocks platelet secretion. The inhibition of secretion, at least in part, is responsible for diminished platelet aggregation and prolonged bleeding times observed in Rac1 knockout or Rac1 inhibitor-treated mice.

Risk factor analysis of permanent pacemaker infection.

Background. Several host- and procedure-related factors have been reported to increase the risk of permanent pacemaker (PPM) infection on the basis of descriptive analyses of case series. The purpose of this study is to assess the risk factors for PPM infection using case-control study methods.Methods. All patients who had a PPM implanted at our institution from January 1991 to December 2003 were retrospectively reviewed. Each patient who experienced a PPM infection was matched with 2 control subjects by age, sex, year of implantation, and duration of follow-up. Univariate and multivariable analyses were performed to identify significant risk factors for PPM infection.Results. Twenty-nine case patients and 58 control subjects met inclusion criteria. The majority (83%) of case patients presented with a pocket infection; a minority (10%) had PPM-related endocarditis. Staphylococcus species (69%) were the most common pathogens. On univariate analysis, previous PPM infection, malignancy, long-term corticosteroid use, multiple device revisions, a permanent central venous catheter, the presence of >2 pacing leads, and a lack of antibiotic prophylaxis at the time of PPM placement were associated with an increased risk of PPM infection. A multivariable logistic regression model identified long-term corticosteroid use (odds ratio [OR], 13.90; 95% confidence interval [CI], 1.27-151.7; P=.03) and the presence of >2 pacing leads versus 2 leads (OR, 5.41; 95% CI, 1.44-20.29; P=.01) as independent risk factors for PPM infection. In contrast, use of antibiotic prophylaxis prior to PPM implantation had a protective effect (OR, 0.087; 95% CI, 0.016-0.48; P=.005).Conclusions. These findings should assist clinicians in identifying patients who are at increased risk of PPM infection, as well as in developing strategies to minimize the modifiable risks.

Secundum-type atrial septal defects with failure to thrive in the first year of life.

This article summarizes the case histories of six infants who had isolated secundum-type atrial septal defects (ASDs) and presented with failure to thrive in the first year of life. Patients underwent operative closure of their ASD with the expectation that this would improve their feeding and growth pattern. Five of the six children demonstrated little or no improvement in symptoms following operation. Each of these five patients have subsequently shown signs of developmental delay. Our experience with this group suggests that failure to thrive associated with a secundum ASD will frequently have a noncardiac basis.

Seroepidemiology of HBV and HCV infection in Jakarta, Indonesia.

A total of 545 serum samples were consecutively collected from patients with acute hepatitis, chronic hepatitis, liver cirrhosis, hepatocellular carcinoma, chronic hemodialysis and voluntary blood donors to study the seroepidemiology of HBV and HCV infection in Jakarta. Fourteen out of 243 or 5.8% samples from blood donors were HBsAg-positive, while HCV-antibodies (anti-C100 and/or anti-CP9 and/or anti-CP10) positivity rate was found in 59 out of 243 or 24.3%. Out of 91 donors aged 29 years or younger, 15 (16.5%) donors turned positive for HCV-antibody (-ies), while out of 152 donors aged 30 years or above, 44 (28.9%) donors were anti-HCV-positive, showing a higher HCV-antibody prevalence among higher age group. Among 88 acute hepatitis patients, 33 (37.5%) cases, 10 (11.4%) cases, 15 (17.0%) cases and 30 (34.1%) cases were diagnosed as hepatitis A, hepatitis B, acute exacerbation of HCV carriers, and NANB hepatitis respectively. HCV-antibodies were found in 15 (45.5%) of hepatitis A cases and 6 (40.0%) of acute exacerbation of HBV carrier cases, but found only in 9 (30.0%) of acute NANB hepatitis cases. Positivity rates of HCV-antibodies among 23 chronic hepatitis, 80 liver cirrhosis and 64 hepatocellular carcinoma cases were 78.3%, 75.0% and 65.6% respectively, while 30.4%, 30.0% and 45.3% of the respective groups were positive for HBs antigen. Among 47 hemodialysis cases, 97.9% and 6.4% were positive for HCV antibodies and HBs antigen respectively. It was concluded that: (1) HBV infection rate is high among blood donors and patients with acute and chronic liver diseases. (2) HCV infection rate is high among blood donors.(ABSTRACT TRUNCATED AT 250 WORDS)

Investigation of the effects of phospholipase C on human platelets: evidence that aggregation induced by phospholipase C is independent of prostaglandin generation, released ADP and is modulated by cyclic AMP.

Effects and the mechanism of action of phospholipase C (PLC), from Clostridium perfringens, on washed human platelets were examined to better understand the role of PLC in platelet function. PLC caused aggregation and secretion of [14C]-5HT, without concomitant loss of cytoplasmic, LDH, in a concentration dependent manner. P-nitrophenylphosphorylcholine, a substrate for PLC, blocked these responses in a concentration dependent manner. In other experiments hirudin, alpha-1-antitrypsin and soybean trypsin inhibitor did not inhibit PLC-induced activation of human platelets. PLC-induced aggregation and [14C]-5HT secretion was not inhibited by aspirin, a known inhibitor of prostaglandin biosynthesis. PLC-induced aggregation was selectively inhibited by analogs of 7,8-dihydroxybenzazepine and 7,8-methylenedioxybenzazepine in a concentration dependent manner. These two agents had no effect on arachidonic acid-induced aggregation. PLC-induced aggregation was not inhibited by apyrase, an enzyme which hydrolyzes ADP. In other experiments, PLC-treated platelets did not exhibit any platelet activating factor-like activity. Prostaglandin E1 and trifluoperazine showed concentration dependent inhibitor effects on PLC-mediated aggregation and secretion of [14C]-5HT. These findings indicate that: a) PLC is capable of inducing aggregation and specific secretion of [14C]-5HT without causing lysis of platelets; b) mechanism of PLC-induced activation of platelets is independent of prostaglandin generation or action, released ADP, and PAF; and c) cyclic AMP plays a modulatory role in PLC-mediated secretion and aggregation of human platelets.