Effect of halothane, isoflurane and desflurane on lower oesophageal sphincter tone

We have studied the effects of volatile anaesthetics on lower oesophageal sphincter (LOS) tone in three groups of eight pigs allocated randomly to receive end-tidal concentrations of 0.5, 1.0 and 1.5 MAC of desflurane, isoflurane or halothane for 15 min. LOS and oesophageal barrier pressures (BrP = LOSP - gastric pressure) were measured using a manometric method. The decrease in BrP paralleled the decrease in LOS pressure and was significant at 0.5 MAC for isoflurane and at 1.0 MAC for halothane. At 1.5 MAC, BrP values were approximately 62% of baseline values for halothane, 37% for isoflurane and 83% for desflurane. Inter-group comparisons showed that BrP did not differ at baseline and at 0.5 MAC. At 1.0 MAC the effect of isoflurane on BrP was significantly different from desflurane (P < 0.001) and halothane (P < 0.02) whereas the effect of desflurane on BrP was not significantly different from halothane. At 1.5 MAC the effect of isoflurane on BrP was significantly different from desflurane (P < 0.01) and halothane (P < 0.05) whereas the effect of desflurane on BrP was not significantly different from halothane. We conclude that desflurane maintained BrP and this may be clinically important in patients at high risk of regurgitation.     

Metabolic response to lactitol and xylitol in healthy men

Sugar alcohols are used in food products, yet their metabolic effects in humans are poorly known. We examined plasma glucose, insulin, and C-peptide responses and changes in carbohydrate and lipid oxidation after the ingestion of 25 g lactitol, xylitol, or glucose. Eight healthy, nonobese men were studied after an overnight fast. After the ingestion of lactitol or xylitol, the rise in plasma glucose, insulin, and C-peptide concentrations was less than after the ingestion of glucose (P < 0.02), with no difference between the two polyols. With the glycemic index of glucose as 100, the indexes of xylitol and lactitol were 7 and -1, respectively. A reactive hypoglycemia was observed 3 h after glucose ingestion, but not after the ingestion of sugar alcohols. There were no significant changes in the carbohydrate or lipid oxidation as determined by indirect calorimetry after the ingestion of sugar alcohols. After glucose ingestion, the rise in carbohydrate oxidation was nearly significant (P = 0.07). In conclusion, lactitol and xylitol cause smaller changes than does glucose in plasma glucose and insulin concentrations and thermogenic response. A small hormonal response and the lack of a thermogenic effect may be beneficial when these sugar alcohols are used in food products. The small glucose and insulin responses also suggest that lactitol and xylitol are suitable components of the diet for diabetic patients.     

Investigation of film curing stages by dielectric analysis and physical characterization

A previously published sequence of the 23S rRNA gene of Coxiella burnetii has been reported to contain an intervening sequence of 444 base pairs (bp). The sequence information on the intervening sequence and the 23S rRNA gene was exploited to develop a specific PCR-based assay for C. burnetii. A primer set was designed that amplified a 477-bp fragment encompassing part of the intervening sequence and part of the 23S rDNA. From all of nine C. burnetii strains tested, a fragment of the expected size was amplified. As predicted from the published sequence, restriction endonuclease digestion of the PCR product from the Coxiella strains with RsaI produced two distinct fragments approximately 210- and 270-bp in size. The PCR-based method showed a detection limit of 10(2) bacteria as determined by visualization of the amplicon on an agarose gel. When experimentally infected blood was analyzed, the detection limit was 10(3) bacteria. No visible amplicons were observed when 41 bacterial strains, representing 29 species other than C. burnetii, were tested. The presence of the DNA in all bacterial samples was confirmed by amplification of a 350-bp fragment of the 16S rDNA using two universal primers. The described method proved to be specific for C. burnetii and may become a rapid and sensitive diagnostic assay for C. burnetii. The results also demonstrate that the intervening sequence within the 23S rRNA gene is generally found among isolates of C. burnetii.     

Increased gelatinase A (MMP-2) and gelatinase B (MMP-9) activities in human brain after focal ischemia

Matrix metalloproteinases (MMPs) are involved in remodelling extracellular matrix. Gelatinase B (MMP-9) is an inducible 92 kDa MMP expressed by neutrophils, microglia, and endothelial cells. Gelatinase A (MMP-2) is a 72 kDa MMP, constitutively expressed in brain. Elevated MMP activity has been linked to various pathologic conditions, and the therapeutic benefit of MMP inhibitors is under study in a few experimental models. Using gelatin zymography, we have compared activities of these MMPs in infarcted and matched non-infarcted cerebral tissue from eight subjects dying at intervals of less than 2 h to several years after a stroke. Gelatinase B activity was markedly elevated in the infarcted tissue at two days post-infarction, and remained elevated in cases dying months after the event. Increases in gelatinase A activity were subtle at 2-5 days; they were marked and significant in cases dying at 4 months and later. The findings indicate distinct temporal profiles of post-ischemic gelatinase activity in human brain, with earlier but equally persistent elevation in gelatinase B when compared to gelatinase A.     

A simple method for delivering morpholino antisense oligos into the cytoplasm of cells

Based on the initial optimization of DMEM:F12(1:1), two kinds of serum-free media, 11G-SG-SFM and 11G-SE-SFM, were formulated by using orthogonal experiments for the growth of genetically engineered CHO cell line 11G and the production of recombinant prourokinase (pro-UK) in a suspension culture, respectively. Growth of 11G cells in 11G-SG-SFM was comparable with that observed in DMEM:F12 + 5% NBS and CHO-S-SFM. 11G cells grew slowly in 11G-SE-SFM, but secreted a relatively high level of pro-UK. The pro-UK productivity of 11G cells in 11G cells in 11G-SE-SFM reached 800 to 1,000 IU/10(6). d-1 and was about 80% and 20% higher than in DMEM:F12 + 5% NBS and CHO-S-SFM, respectively.     

MAP 2.1 conformance testing tools

The major components of the MAP 2.1 conformance test system are described. Protocol conformance testing and program testing are compared. The scope and process of dynamic conformance testing is reviewed. The architecture of the tests system is presented, first in terms of the developing ISO (International Organization for Standardization) framework, and then in terms of run-time components. Several specific tools which comprise the test system are described. These tools include test engines, a high-level control tool, monitoring and analysis tools, and document handling tools. Benefits and limitations of the test tools are examined. Conclusions and suggestions for future efforts are provided     

Electrocardiographic manifestations following electric injury

Bromomethane (BM) is a fumigant used in agriculture; it readily breaks down to bromide ion. WHO assessed the ADI of BM, at 1 mg/kg, using data on the toxicity of bromide. On the other hand, U.S. EPA used the observation of hyperplasia in the forestomach of rats given BM by gavage and arrived at a value of 0.0014 mg/kg. The validity of EPA's assessment is thus subject to question because of the data involved by (1) direct introduction of this volatile and reactive chemical to the GI by gavage and (2) using lesions in the rat forestomach which is absent in humans.     

Guidelines for determining and reporting food yields

The author discusses problems in compiling and evaluating data and recommends a standard protocol for determing yield of food. The recent extensive revision of Agriculture Handbook No. 102, Food Yields Summarized by Different Stages of Preparation, points up the urgent need for guidelines and a standard protocol.