The importance of the pylorus as a regulator of solid and liquid emptying from the stomach

The role of the pylorus in the control of gastric emptying of liquids and digestible solids was investigated in the present study by pylorus excision in six pigs. The pylorus was left intact in another six pigs. Antro-pyloro-duodenal motility was recorded by a sleeve sensor and side holes. Liquid emptying was significantly more rapid in pylorus excised than in pylorus intact animals, during intraduodenal infusion of isosmolar dextrose (712 mL vs 107 mL), fatty acid (402 mL vs 46 mL), amino acids (752 mL vs 112 mL), 25% dextrose (392 mL vs 51 mL) and 3 normal saline (705 mL vs 157 mL). In pylorus excised animals, in contrast to pylorus intact animals, the manometric pattern of isolated pyloric pressure waves at the distal stomach was rarely seen (P < 0.05). In a second series of experiments, pylorus excised animals emptied significantly more (P < 0.04) meat over 120 min (181 g) than pylorus intact animals (80 g), but the proportion of particle sizes emptied was unaltered. In the pig, localized pyloric contractions are important for retardation of gastric emptying when nutrient or hyperosmolar solutions enter the duodenum. By contrast, the pylorus is unimportant in determining the size of solid particles emptied from the stomach.     

Antibiotic management of pneumococcal infections in an era of increased resistance

Abstract: Pneumococci are a leading cause of bacterial meningitis and bacteraemia, as well as pneumonia, otitis media and sinusitis in childhood. These organisms recently have shown a dramatic increase in antibiotic resistance. Penicillin-resistant pneumococci are of special concern as they are often resistant to other unrelated antibiotics. This is of particular significance to Aboriginal children who have among the highest rates of pneumococcal infection in the world. Laboratories should now test all invasive pneumococcal isolates for penicillin and third generation cephalosporin resistance. Local treatment guidelines are required for pneumococcal infections, especially for meningitis, taking into account the prevalence of resistant strains within the community. At present, penicillin and amoxycillin remain the drugs of choice for pneumococcal infections, with the exception of meningitis where initial empirical therapy must be with a third generation cephalosporin. Judicious antibiotic use, which avoids over-prescribing and unnecessary use of broad-spectrum agents, improved living standards in underprivileged communities and introduction of an effective conjugate vaccine, able to reduce the rates of pneumococcal infection and hopefully colonization, may limit the spread of resistant strains.     

An unusual pattern of mutation in the duplicated portion of PKD1 is revealed by use of a novel strategy for mutation detection

The gene for the most common and severe form of autosomal dominant polycystic kidney disease, PKD1, encodes a 14 kb mRNA that is predicted to result in an integral membrane protein of 4302 amino acids. The major challenge faced by researchers attempting to complete mutation analysis of the PKD1 gene has been the presence of several homologous loci also located on chromosome 16. Because the sequence of PKD1 and its homologs is nearly identical in the 5' region of the gene, most traditional approaches to mutation analysis cannot distinguish sequence variants occurring uniquely in PKD1. Therefore, only a small number of mutations have been identified to date and these have all been found in the 3', unique portion of the gene. In order to begin analysis of the duplicated region of PKD1, we have devised a novel strategy that depends on long-range PCR and a single gene-specific primer from the unique region of the gene to amplify a PKD1-specific template that spans exons 23-34. This 10 kb template, amplified from genomic DNA, can be employed for mutation analysis using a wide variety of sequence- based approaches. We have used our long-range PCR strategy to begin screening for sequence variants with heteroduplex analysis, and several affected individuals were discovered to have clusters of base pair substitutions in exons 23 and 25. In two patients, these changes, identified in exon 23, would be predicted to result in multiple amino acid substitutions in a short stretch of the protein. This clustering of base pair substitutions is unusual and suggests that mutation may result from unique structural features of the PKD1 gene.      

近红外光谱技术在元胡止痛散定量分析中的初步应用研究

目的为元胡止痛散建立一种快速有效的定量分析方法,并为将近红外光谱分析技术应用于中药的定量分析提供指导。方法按处方配制25个模拟样本,随机挑选18个组成训练集,另外7个组成预示集,采集各样本的近红外光谱数据,用BP神经网络和PIS法对数据进行处理,并实际分析了三批样品。结果模拟样本中,对于元胡,采用BP网络和PLS法,平均相对预示误差分别为1．5％,2．5％,对于白芷,平均相对预示误差分另为2．9％,4．4％,对于实际样本,各组分标示量的百分含量都在95％～105％之间。结论近红外光谱结合BP神经网络或PLS应用于元胡止痛散的定量分析是可行和有效的。     

肝硬化门静脉高压症患者内脏血流动力学紊乱的研究

门静脉高压症是一种由多种病因引起门静脉系统血液动力学紊乱的临床综合征。本研究,应用多普勒超声检测,正常人和肝硬化门静脉高压症患者门静脉系统血流量,以了解肝硬化门静脉高压症中门静脉血流动力学的变化。临床资料１９９６年３月至１９９７年４月用多普勒超声（ＤＵＳ）检测２０例健康成人和３４例门脉高压患者门静脉系统血流动力学参数。２０例健康成人（男１６例,女４例,平均年龄为４９．９５±１５．４９岁）为我院行健康体检者。３４例门脉高压患者中,男３１例,女３例,平均年龄为５０．００±１２．７８岁,病因为肝炎后肝…     

Lung responses to secondary endotoxin challenge in rats exposed to pig barn air

Background

Swine barn air contains endotoxin and many other noxious agents. Single or multiple exposures to pig barn air induces lung inflammation and loss of lung function. However, we do not know the effect of exposure to pig barn air on inflammatory response in the lungs following a secondary infection. Therefore, we tested a hypothesis that single or multiple exposures to barn air will result in exaggerated lung inflammation in response to a secondary insult with Escherichia coli LPS (E. coli LPS).

Methods

We exposed Sprague-Dawley rats to ambient (N = 12) or swine barn air (N = 24) for one or five days and then half (N = 6/group) of these rats received intravenous E. coli LPS challenge, observed for six hours and then euthanized to collect lung tissues for histology, immunohistochemistry and ELISA to assess lung inflammation.

Results

Compared to controls, histological signs of lung inflammation were evident in barn exposed rat lungs. Rats exposed to barn air for one or five days and challenged with E. coli LPS showed increased recruitment of granulocytes compared to those exposed only to the barn. Control, one and five day barn exposed rats that were challenged with E. coli LPS showed higher levels of IL-1β in the lungs compared to respective groups not challenged with E. coli LPS. The levels of TNF-α in the lungs did not differ among any of the groups. Control rats without E. coli LPS challenge showed higher levels of TGF-β2 compared to controls challenged with E. coli LPS.

Conclusion

These results show that lungs of rats exposed to pig barn air retain the ability to respond to E. coli LPS challenge.     

The roles of von Willebrand factor and factor VIII in arterial thrombosis: studies in canine von Willebrand disease and hemophilia A

We have studied the roles of von Willebrand factor (vWF) and factor VIII in arterial thrombosis in four canine phenotypes: normal (n = 6), hemophilia A (n = 11), von Willebrand disease (vWD) (n = 9), and hemophilia A/vWD (n = 1). vWF activity was determined by botrocetin- induced agglutination of fixed human platelets and vWF antigen (vWF:Ag) by Laurell electroimmunoassay and crossed immunoelectrophoresis. Plasma from normal dogs and those with hemophilia A had vWF activity, vWF:Ag, and a full range of vWF:Ag multimers on gel electrophoresis equivalent to normal canine plasma pool. Platelet cytosol contents were isolated by freezing and thawing, triton X-100 solubilization, or sonication of washed platelets with and without protease inhibitors and inhibitors of platelet activation. Washed platelets were also stimulated with calcium ionophore and MgCl2. There was no measurable vWF activity or vWF:Ag in platelet lysates or releasates in any dog regardless of phenotype. All dogs were studied using a standard arterial stenosis and injury procedure to induce arterial thrombosis. Thromboses were detected by cyclic reductions in Doppler blood flow velocity. Vessels were examined by light and scanning electron microscopy. Thrombosis developed in the arteries of normal (9 of 10) and hemophilia A dogs (16 of 16) but in none of the vWD dogs (0 of 10). Infusion of canine vWF cryoprecipitate into vWD dogs markedly shortened bleeding time but did not support thrombosis as seen in dogs with vWF in the plasma and subendothelium. Thrombosis, then, fails to occur when vWF is absent from the plasma and subendothelial compartments or present only in the plasma compartment. These data are consistent with the hypothesis that vWF in the plasma and subendothelium supports thrombosis. Neither plasma FVIII nor platelet vWF is essential for thrombosis in this model.     

The efficacy of 'Radio guided Occult Lesion Localization' (ROLL) versus 'Wire-guided Localization' (WGL) in breast conserving surgery for non-palpable breast cancer: A randomized clinical trial – ROLL study

Background

The gold standard for assessment of intraabdominal pressure (IAP) is via intravesicular pressure measurement (IVP). This accepted technique has some inherent problems, e.g. indirectness. Aim of this clinical study was to assess direct IAP measurement using an air-capsule method (ACM) regarding complications risks and agreement with IVP in patients undergoing abdominal surgery.

Methods

A prospective cohort study was performed in 30 patients undergoing elective colonic, hepatic, pancreatic and esophageal resection. For ACM a Probe 3 (Spiegelberg^®, Germany) was placed on the greater omentum. It was passed through the abdominal wall paralleling routine drainages. To compare ACM with IVP t-testing was performed and mean difference as well as limits of agreement were calculated.

Results

ACM did not lead to complications particularly with regard to organ lesion or surgical site infection. Mean insertion time of ACM was 4.4 days (min-max: 1–5 days). 168 pairwise measurements were made. Mean ACM value was 7.9 ± 2.7 mmHg while mean IVP was 8.4 ± 3.0 mmHg (n.s). Mean difference was 0.4 mmHg ± 2.2 mmHg. Limits of agreement were -4.1 mmHg to 5.1 mmHg.

Conclusion

Using ACM, direct IAP measurement is feasible and uncomplicated. Associated with relatively low pressure ranges (<17 mmHg), results are comparable to bladder pressure measurement.     

Successful treatment of epiglottitis with two doses of ceftriaxone

Epiglottitis in childhood is caused by Haemophilus influenzae type b. The usual antibiotic treatment at the Royal Children's Hospital, Parkville, Victoria is a five day course of chloramphenicol. Increasingly, third generation cephalosporins are being used to treat invasive H influenzae type b infections and preliminary data suggest that they can be used successfully for epiglottitis. In a prospective, randomised trial, the efficacy of a short course (two days) of ceftriaxone was compared with that of five days of chloramphenicol for the treatment of epiglottitis. The ability of these treatment regimens to eradicate H influenzae type b from the throat was also studied. Fifty five children were enrolled over an 18 month period. Epiglottitis was diagnosed clinically and confirmed on inspection of the epiglottis at direct laryngoscopy. Fifty three (96%) of 55 patients had H influenzae type b detected from at least one site: 44/52 (85%) from blood cultures, 41/47 (87%) from throat swab, and 6/8 (75%) as H influenzae type b urinary antigen. Children were randomised to receive either ceftriaxone 100 mg/kg intravenously followed by a single dose of 50 mg/kg 24 hours later (28 patients), or chloramphenicol 40 mg/kg intravenously, then 25 mg/kg eight hourly for five days, intravenously then by mouth (27 patients). All household contacts and patients receiving chloramphenicol received rifampicin 20 mg/kg daily for four days. Index patients randomised to ceftriaxone were not treated with rifampicin. There was no significant difference in outcome between the two groups with respect to the mean duration of fever, the duration of intubation, or the length of hospital admission. The proportion of patients colonised with H influenzae type b four weeks after discharge was not significantly different between the two groups: ceftriaxone 5/22 (23%) versus chloramphenicol and rifampicin 3/23 (13%). A short course of ceftriaxone was successful in treating all patients with no significant side effects and no relapses. A short course of ceftriaxone is a safe, efficacious, and economic alternative to the standard treatment in children with epiglottitis.     

Biologic properties in vitro of a recombinant human granulocyte- macrophage colony-stimulating factor

Recombinant human granulocyte-macrophage colony-stimulating factor (rH GM-CSF) was purified to homogeneity from medium conditioned by COS cells transfected with a cloned human GM-CSF cDNA and shown to be an effective proliferative stimulus in human marrow cultures for GM and eosinophil colony formation. The specific activity of purified rH GM- CSF in human marrow cultures was calculated to be at least 4 X 10(7) U/mg protein. Clone transfer experiments showed that this proliferation was due to direct stimulation of responding clonogenic cells. Acting alone, rH GM-CSF did not stimulate erythroid colony formation, but in combination with erythropoietin, increased erythroid and multipotential colony formation in cultures of peripheral blood cells. rH GM-CSF had no proliferative effects on adult or fetal murine hematopoietic cells, did not induce differentiation in murine myelomonocytic WEHI-3B cells, and was unable to stimulate the survival or proliferation of murine hematopoietic cell lines dependent on murine multi-CSF (IL 3). rH GM- CSF stimulated antibody-dependent cytolysis of tumor cells by both mature human neutrophils and eosinophils and increased eosinophil autofluorescence and phagocytosis by neutrophils. From a comparison of these effects with those of semipurified preparations of human CSF alpha and -beta, it was concluded that rH GM-CSF exhibited all the biologic activities previously noted for CSF alpha.