Evaluation of proteolytic activity of micro-organisms isolated from dry cured ham

BACKGROUND: Morphologic changes of the vascular endothelium are common in patients with systemic sclerosis and Raynaud's phenomenon. The aim of this study was to evaluate the endothelium-dependent vasodilatation and endothelium-independent vasodilatation and to examine the effects of short-term estrogen administration on vascular responses in these patients. METHODS AND RESULTS: The study included 12 female patients with systemic sclerosis and Raynaud's phenomenon (aged 49+/-14 years) and 12 age- and sex-matched healthy control subjects. With the use of high-resolution ultrasound imaging, brachial artery diameter was measured at rest, during reactive hyperemia (endothelium-dependent response), and after administration of sublingual nitroglycerin (endothelium-independent dilatation). Intima-media thickness of the common carotid artery was also measured. Baseline diameter was similar in patients and control subjects; intima-media thickness was significantly higher in patients (0.83+/-0.3 vs 0.46+/-0.2 mm, P= .002) than in control subjects. Flow-mediated dilatation was reduced in patients (3.6%+/-7% vs 11.9%+/- 4.6%, P = .003); endothelium-independent dilatation also was reduced in patients with Raynaud's phenomenon (14%+/-7% vs 23%+/-6%, P= .003). Vascular responses in 10 patients were examined 15 minutes after administration of conjugated estrogens (25 mg intravenously); there was a significant increase of endothelium-dependent dilatation after estrogen administration (1.7%+/-4% to 6.3%+/-4%, P= .01), whereas endothelium-independent dilatation did not change (13.4%+/-8% to 15.5%+/-7%, not significant). CONCLUSIONS: Endothelium-dependent vasodilatation and endothelium-independent vasodilatation are impaired in patients with Raynaud's phenomenon secondary to systemic sclerosis, whereas intima-media thickness is increased. Short-term estrogen administration can improve endothelial dysfunction in this group of patients.     

Effect of relative humidity on fungal colonization of fiberglass insulation

Fiberglass duct liners and fiberglass duct boards from eight buildings whose occupants complained of unacceptable or moldy odors in the air were found to be heavily colonized by fungi, particularly by Aspergillus versicolor. Unused fiberglass was found to be susceptible to fungal colonization in environmental chambers dependent upon relative humidity. No colonization was observed at relative humidities below 50%.     

Effects of sodium chloride and shot peening on corrosion fatigue of AISI 6150 steel

Reversed-bending fatigue tests of quenched and tempered AISI 6150 steel were conducted in dry air and in aqueous 3 pct NaCl. The 3 pct NaCl environment drastically reduced fatigue life but two different shot peening treatments were found to improve the corrosion fatigue life over that of unpeened samples. Multiple fatigue crack initiation occurred at very distinct locations in both the unpeened and the peened specimens fatigued in 3 pct NaCl. Fatigue crack propagation from each initiation site occurred first on flat facets normal to the stress axis and then by a more ductile mechanism after the initiation facets had linked. The average size of the corrosion fatigue initiation facets in the peened specimens was much smaller than that of the unpeened specimens; however, the number of initiation sites was greater in the peened specimens. It is believed that the beneficial effect of the shot peening results from significantly reduced early fatigue crack propagation rates in the compressive residual stress layer at the surface. Formerly Research Assistant, Materials Department, University of Wisconsin-Milwaukee     

空气相对湿度对焊缝质量的影响分析

通过对法兰盘焊接时存在的气孔缺陷的研究与分析,找出了问题存在的各种原因,由于焊接环境的特殊性,空气相对湿度是引起气孔缺陷的主要原因,针对空气相对湿度较高这一原因,提出了焊前预热、改进工艺和选择高水平操作者的改进措施,使得产品质量有了很大的提高。     

Effects of age and sex on sodium chloride sensitivity: association with plasma renin activity

The mechanism by which excessive NaCl intake raises blood pressure has not been fully clarified. The present study was undertaken in 87 Japanese inpatients with essential hypertension to investigate the interrelation among effects of age, sex and the renin-angiotensin system on NaCl sensitivity. After ingesting a regular NaCl diet (170 mmol/day) for one week, subjects were placed sequentially on a week of low NaCl diet (50 mmol/day) and a week of high NaCl diet (340 mmol/day). NaCl sensitivity defined as the difference in mean blood pressure between the low and high NaCl diets did not differ between genders. NaCl sensitivity was positively correlated with age and the change in PRA. The fall in PRA after NaCl loading was significantly smaller in women than in men. By multiple regression analysis, age and the change in PRA independently contributed to the change in mean blood pressure. Furthermore, the interaction between sex and the change in PRA was selected as a statistically significant variable. In conclusion, NaCl sensitivity of blood pressure is independently associated with age and the inadequate suppression of the renin-angiotensin system. Because the contribution of the change in PRA to NaCl sensitivity was greater in women than in men, the mechanism of blood pressure elevation after NaCl loading may differ between genders.     

Effect of polyphosphate and sodium chloride on the growth of Listeria monocytogenes and Staphylococcus aureus in ultra-high temperature milk

With UHT-sterilized milk as a model system, combinations of polyphosphate (.5 and 1.0%) and NaCl (.5 and 4.5%) were studied to determine their effects on the growth kinetics of Listeria monocytogenes Scott A and Staphylococcus aureus 196E. The milk was inoculated with 10(3) to 10(4) cfu/ml of either L. monocytogenes or S. aureus and incubated under aerobic conditions at 12, 19, 28, or 37 degrees C. The addition of polyphosphate did not significantly inhibit the growth of either microbe at the temperatures studied, but the addition of NaCl or a combination of salts significantly inhibited growth. The addition of .5 or 1.0% polyphosphate alone to dairy products is not likely to affect substantially the growth of S. aureus or L. monocytogenes.     

Effects of fish meal and sodium bentonite on daily gain, wool growth, carcass characteristics, and ruminal and blood characteristics of lambs fed concentrate diets

We evaluated the effects of replacing some soybean meal (SBM) protein with fish meal (FM) protein in diets adequate and slightly deficient in CP, with or without .75% sodium bentonite (NaB) on performance and ruminal and blood metabolites of individually fed Suffolk lambs. Diets were based on corn, SBM, and cottonseed hulls. In Exp. 1, five lambs were assigned to each of the three dietary treatments (11% CP with 3% FM, 13% CP with 0 or 3% FM). Lambs fed diets that contained 11% CP with 3% FM or 13% CP with 0% FM had similar DMI and ADG. Gain and feed efficiency were slightly improved (P = .18) by the 13% CP diet with 3% FM. In Exp. 2, 32 lambs were assigned to four dietary treatments (13.5% CP of DM) in a 2 x 2 factorial arrangement (0 or 3% FM, and 0 or .75% NaB on an as-fed basis). The DMI and ADG were increased (P < .05) by FM and NaB supplementation. Interactions (P < .05) revealed that NaB increased DMI, ADG, gain per feed (g/kg of DMI), and plasma urea N concentration in the absence of FM but not in the presence of FM in the diet. Neither FM nor NaB influenced (P = .25) wool growth. Total ruminal VFA were increased (P < .06) by FM and NaB. Differences in mineral content of phalanx bone, liver, and kidney were small and may be related to the mineral content of diets and the effect of NaB on mineral solubilities. Similar DMI and ADG of lambs fed FM and NaB separately and in combination suggest that their beneficial effect is not additive.     

Sodium chloride transport across the chicken coprodeum. Basic characteristics and dependence on sodium chloride intake

1. The transport characteristics of the chicken coprodeum have been examined in vitro using the isolated mucosa. The short-circuit current (I(sc)), the transepithelial electrical potential difference (p.d.), the unidirectional transmural fluxes (J(ms), J(sm)) of sodium and chloride measured in the short-circuited state, and the unidirectional influx of sodium and chloride across the brush border membrane measured under open-circuit conditions have been studied. The effect of the sodium chloride contents of the diet on these parameters have been investigated.2. The isolated mucosa depends functionally on the presence of glucose in the incubation media. This dependence reflects the need of glucose as a fuel. There is no indication of coupling between transport of sugars and sodium across the brush border membrane. For preparations from chickens on a low sodium diet a very high and stable I(sc) can quantitatively be accounted for by the net transport of sodium. Influx of sodium across the brush border membrane is not significantly different from the net flux of sodium. By feeding the chickens a high sodium diet the I(sc) is reduced by more than 95%, the net transport of sodium is abolished, and the transepithelial electrical conductance is reduced by more than 50%.3. Both unidirectional transepithelial fluxes of chloride, and the serosa to mucosa flux of sodium appear to proceed through a paracellular shunt.4. Under the conditions of the low sodium diet the paracellular pathway appears to be anion selective. Whereas, under the conditions of the high sodium regimen the paracellular route appears to be cation selective. After adaptation to a high sodium diet the influx of sodium across the brush border membrane is only moderately reduced. Consequently the decisive event in the adaptation must be localized elsewhere.     

Short-term effect of epidermal growth factor (EGF) on sodium and glucose cotransport of isolated jejunal epithelial cells

This study was undertaken to assess the short-term effects of EGF on sodium and glucose uptake, glucose metabolism and Na+/K(+)-ATPase activity in isolated enterocytes of rats. Jejunal cells exposed to EGF had a significantly greater total uptake of sodium compared to controls after 6 min. Kinetic analysis of glucose transport across BBMV's demonstrated similar Km values but a significant increase of the Vmax in vesicles prepared from cells first exposed to EGF as compared to controls. EGF was also associated with a significant increase in glucose metabolism of jejunal enterocytes after 15 min. The activity of Na+/K(+)-ATPase increased in jejunal enterocytes exposed to EGF. The increase in Na+/K(+)-ATPase activity of the cells following EGF exposure was not accompanied by an increase in immunodetectable total or assembled Na+/K(+)-ATPase protein. EGF's effect on enzyme activity was abolished by removing NaCl from the incubation solution, and by preincubating the enterocytes with phlorizin prior to addition of EGF. Preincubation with amiloride did not inhibit the effect of EGF on Na+/K(+)-ATPase. The results confirm that EGF promotes uptake of both sodium and glucose by the jejunal mucosal cells, and suggest the effect of EGF on glucose and sodium is mediated through the brush-border membrane glucose-sodium transporter. The increase in Na+/K(+)-ATPase activity that occurs with EGF appears to be secondary to a rise in intracellular Na+ concentration. The short-term effects of EGF on glucose and sodium transport by the small intestine may have potential therapeutic implications.     

用乳状液膜从氯化钠型浸出液中浓缩稀土

考察了用乳状液膜从氯化钠型浸出液中浓缩稀土过程中工艺因素的影响：油内比、膜相中煤油和液体石蜡的比例、表面活性剂用量、内相酸度、料液中稀土浓度、水乳比、Ｐ５０７ 和Ｐ２０４ 的比较以及搅拌时间等。通过实验， 获得了乳状液膜浓缩稀土的适宜配方以及较佳的操作条件，乳状液膜浓缩稀土的浓度可达１０６ｇ／Ｌ，稀土提取率可达９４ ％ 。     

Effects of relative band intensity on prediction of protein secondary structure from CD

Increasing the magnitude of a protein CD spectrum obviously increases the magnitude of each predicted secondary structure by the same amount. However, increasing the magnitude of the negative, long-wave-length portion of a protein CD spectrum usually has the opposite effect from increasing the positive, short-wave-length portion. Thus small distortions in the CD spectra of proteins at short wavelength can have a significant effect on the analysis for secondary structure. This measurement error and its effect on the analysis are systematically investigated for 16 proteins of known structure. The results demonstrate that a two-point calibration of a CD instrument is mandatory to avoid serious errors when estimating secondary structure from protein CD spectra.     

The molecular mobility of supercooled amorphous indomethacin as a function of temperature and relative humidity

PURPOSE: To determine the relaxation times of supercooled indomethacin as a function of temperature and relative humidity above Tg, and to analyze the results in the context of being able to predict such behavior at various storage conditions. METHODS: Dielectric relaxation times were measured in the frequency domain (12 to 10(5) Hz) for amorphous indomethacin equilibrated at 0, 56, and 83% relative humidity. The heating rate dependence of Tg for dry supercooled indomethacin was measured with differential scanning calorimetry and used to determine relaxation times. The results were compared with previously published shear relaxation times and enthalpy recovery data. RESULTS: Very good agreement was observed between dielectric and shear relaxation times, and those obtained from the heating rate dependence of the Tg, for dry indomethacin as a function of temperature above Tg. The introduction of water lowered the dielectric relaxation times of supercooled indomethacin without significantly affecting its fragility. The relaxation times below Tg, found to be lower than those predicted by extrapolation of the data obtained above Tg, were analyzed in the context of the Adam-Gibbs-Vogel equation. CONCLUSIONS: The relaxation times of amorphous indomethacin obtained from the heating rate dependence of Tg were in good agreement with those obtained from shear and dielectric measurements, thus validating a relatively simple approach of assessing molecular mobility. The significant molecular mobility of amorphous indomethacin observed below Tg, and the significant plasticizing effects of sorbed water, help to explain why amorphous indomethacin crystallizes well below Tg over relatively short time scales.     

Effects of humidity and temperature on in vitro dissolution of carbamazepine tablets

The rate and extent of dissolution of various approved marketed carbamazepine (CBZ) tablets exposed to 33, 52, 75, and 97% relative humidities at both room temperature and 40 degrees C, and saturated water vapor at room temperature were compared to fresh unstressed tablets. The dissolution data indicate that exposure of CBZ tablets to high humidity and temperature can have a profound effect on tablet disintegration and dissolution. The dissolution rates of some batches of CBZ products exposed to 97% humidity at 40 degrees C or saturated water vapor at room temperature were drastically reduced in only 6-7 days.     

Characterization and distribution of amylases during vegetative cell growth and sporulation of Clostridium perfringens

Clostridium perfringens produced eight extracellular and two intracellular amylolytic activities when examined by zymograms following polyacrylamide gel electrophoresis under native conditions. The major intracellular amylase was isolated from vegetative cells of C. perfringens. It possessed an estimated molecular mass of 112 kDa. Sulfhydryl and phenol functional groups were essential to its activity. The amylase was endo-acting on starch and also hydrolyzed pullulan. Polyclonal antisera against a purified extracellular amylase did not cross-react with intracellular amylase and the two amylases were biochemically different. The distribution of extracellular amylolytic activities of sporulating cells was different from that of vegetative cells, whereas the distribution of intracellular amylolytic activities remained identical. A significant increase of a particular amylase (A8) occurred in the extracellular fluid during sporulation compared with that during vegetative growth. Regulation of the excretion of amylase(s) may be sporulation and enterotoxingenicity related.     

Glycine-activated chloride currents of neurons freshly isolated from the ventral tegmental area of rats

This paper describes the preparation and characterisation of poly(lactide-co-glycolide) (PLG) nanoparticles containing the enzyme L-asparaginase. L-Asparaginase was encapsulated in PLG nanospheres using a water-in-oil-in-water solvent evaporation technique. The effect of the copolymer molecular weight and the presence of carboxyl-end groups in the copolymer chain on the physicochemical and in vitro release properties of the nanoparticles was investigated. Results indicated that size, encapsulation efficiency and in vitro release properties (enzymatic activity retention and protein quantification) of the nanoparticles were affected by the PLG molecular weight. As expected, nanoparticles made of high-molecular-weight PLG had a larger size, a higher loading and la slower release rate than those made od a low-molecular-weight PLG. Nevertheless, the most relevant factor affecting the entrapment and release of L-asparaginase from PLG nanoparticles was the presence of free carboxyl-end groups in the PLG chain. The nanoparticles made of PLG with free carboxyl-end groups had a high protein loading (4.86%, w/w) and provided a continuous delivery of the active enzyme for 20 days. However, the enzyme loading was lower (2.65%, w/v) and no active enzyme was detected in the release medium after a 14-day incubation period when nanoparticles were made of PLG with carboxyl-end groups esterified. These results give evidence of the potential of PLG nanospheres for the continuous delivery of L-asparaginase for extended periods of time and show the effect of the PLG chain end-groups in the amount and activity of the enzyme loaded into the nanospheres.