Protection against acute pancreatitis by activation of protease-activated receptor-2

Protease-activated receptor-2 (PAR-2) is a widely expressed tethered ligand receptor that can be activated by trypsin and other trypsin-like serine proteases. In the exocrine pancreas, PAR-2 activation modulates acinar cell secretion of digestive enzymes and duct cell ion channel function. During acute pancreatitis, digestive enzyme zymogens, including trypsinogen, are activated within the pancreas. We hypothesized that trypsin, acting via PAR-2, might regulate the severity of that disease, and to test this hypothesis, we examined the effect of either genetically deleting or pharmacologically activating PAR-2 on the severity of secretagogue-induced experimental pancreatitis. We found that experimental acute pancreatitis is more severe in PAR-2(-/-) than in wild-type mice and that in vivo activation of PAR-2, achieved by parenteral administration of the PAR-2-activating peptide SLIGRL-NH2, reduces the severity of pancreatitis. In the pancreas during the early stages of pancreatitis, the MAPK ERK1/2 is activated and translocated to the nucleus, but nuclear translocation is reduced by activation of PAR-2. Our findings indicate that PAR-2 exerts a protective effect on pancreatitis and that activation of PAR-2 ameliorates pancreatitis, possibly by inhibiting ERK1/2 translocation to the nucleus. Our observations suggest that PAR-2 activation may be of therapeutic value in the treatment and/or prevention of severe clinical pancreatitis, and they lead us to speculate that, from a teleological standpoint, PAR-2 may have evolved in the pancreas as a protective mechanism designed to dampen the injurious effects of intrapancreatic trypsinogen activation.     

Nasal peptide vaccination elicits CD8 responses and reduces viral burden after challenge with virulent murine cytomegalovirus

Infection of BALB/c mice with murine cytomegalovirus (MCMV) leads to CD8 cell responses to an immunodominant epitope YPHFMPTNL. We presented this epitope as a nasal peptide vaccine in combination with cholera toxin adjuvant, and evaluated immune responses and protection from MCMV challenge. Vaccination of naïve mice generated elevated numbers of peptide‐specific interferon‐7‐secreting splenocytes (median 80/million, range 60 to 490), compared to control mice (median 2/million, range —4.5 to 8; P=0.008, Mann‐Whitney test). Twelve days after challenge with virulent MCMV, vaccinated mice had a 1.1 log₁₀ reduction in salivary gland viral titer compared to unvaccinated controls (5.36±0.24 vs. 6.42±0.12, mean±SD log₁₀ plaque‐forming‐units; P<0.001, t‐test). Mice with chronic MCMV infection had consistent responses to the peptide (183±24/million interferon‐γ‐secreting splenocytes). Nasal peptide vaccination during chronic infection boosted peptide‐specific responses in two of four mice to >900/million interferon‐γ‐secreting splenocytes. Nasal peptide vaccination was immunogenic in naïve and MCMV‐infected mice, and reduced viral burden in naïve mice after virulent MCMV challenge. The nasal route may be useful for peptide presentation by novel human vaccines.     

Treatment of overactive bladder and incontinence in the elderly

The prevalence of urinary incontinence (UI) and overactive bladder rises with age, and elderly people are the fastest-growing segment of the population. Many elderly people assume UI is a normal part of the aging process and do not report it to their doctors, who must therefore make the effort to elicit the information from them. Coexisting medical problems in older patients and the multiple medications many of them take make diagnosis and treatment more complex in this population. Just as the etiology of incontinence is often multifactorial, the treatment approach may need to be multipronged, with behavioral, environmental, and medical components; in any case, it must be targeted to the individual patient. New, less-invasive surgical techniques and devices make surgery more feasible if other therapy fails.     

Ethnic-immigrant differentials in health behaviors, morbidity, and cause-specific mortality in the United States: an analysis of two national data bases

This study examines the extent to which various ethnic-immigrant and US-born groups differ in their risks of all-cause and cause-specific mortality, morbidity, and health behaviors. Using data from the National Longitudinal Mortality Study, 1979-1989, we estimated, for major US racial and ethnic groups, mortality risks of immigrants relative to those of the US-born. The Cox regression model was used to adjust mortality differentials by age, sex, marital status, rural/urban residence, education, and family income. Logistic regression was fitted to the National Health Interview Survey data to determine whether health status and behaviors vary among ethnic-immigrant groups and by length of US residence. Compared with US-born whites of equivalent socioeconomic and demographic background, foreign-born blacks, Hispanics, and Asians/Pacific Islanders (APIs), US-born APIs, US-born Hispanics, and foreign-born whites had, respectively, 48%, 45%, 43%, 32%, 26%, and 16% lower mortality risks. While American Indians did not differ significantly from US-born whites, US-born blacks had an 8% higher mortality risk. Black and Hispanic immigrants experienced, respectively, 52% and 26% lower mortality risks than their US-born counterparts. Considerable differentials were also found in mortality for cancer, cardiovascular, respiratory, infectious disease, and injury, and in morbidity and health behaviors, with API and Hispanic immigrants generally experiencing the lowest risks. Consistent with the acculturation hypothesis, immigrants' risks of smoking, obesity, hypertension, and chronic condition, although substantially lower than those for the US-born, increased with increasing length of US residence. Given the substantial nativity differences in health status and mortality, future waves of immigrants of diverse ethnic and cultural backgrounds will likely have a sizeable impact on the overall health, disease, and mortality patterns in the United States.     

Disulfide engineering at the dimer interface of Lactobacillus casei thymidylate synthase: crystal structure of the T155C/E188C/C244T mutant

The crystal structure of a covalently cross-linked Lactobacillus casei thymidylate synthase has been determined at 2.8 A resolution. The sites for mutation to achieve the bis-disulfide linked dimer were identified using the disulfide modeling program MODIP. The mutant so obtained was found to be remarkably thermostable. This increase in stability has been reasoned to be entirely a consequence of the covalent gluing between the two subunits.     

Influence of Linoleic Acid-Induced Oxidative Modification on Gel Properties of Myofibrillar Protein from Silver Carp (<Emphasis Type="Italic">Hypophthalmichthys molitrix</Emphasis>) Muscle

Oxidation extent of myofibrillar protein (MP) from silver carp (Hypophthalmichthys molitrix) was affected by the content and type of lipid peroxidation (LPO) products. Oxidized linoleic acid (OLA) was selected as a main representative of lipid peroxidation to investigate the effects of oxidative modification of LPO products on MP structure. Structural changes of the oxidized myofibrillar protein were evaluated by the contents of carbonyl and total sulfhydryls, surface hydrophobicity, SDS-PAGE and Fourier transform infrared spectroscopy. Heating procedure was also applied for further evaluation of gelling properties. The results from SDS-PAGE indicated that aggregation and denaturation of myosin occurred in the oxidized system. The presence of OLA intensified oxidation-initiated loss of a-helix conformation as well as tertiary structure of MP. With the addition of OLA concentration less than 3 mM, a remarkably enhanced gelling capacity of MP was observed. While the excessive covalent bond (OLA > 5 mM) could lead to the breakage of protein-protein bonds, causing the collapse of the gel structure. The gelation procedure induced by OLA involved simultaneous protein oxidation and internal cross-linking.     

Progeny selection for agronomic characters in early generations of a potato breeding programme

 Repeatabilities of progeny means, and the univariate cross prediction method were used to study the effectiveness of progeny selection for agronomically important characters in early generations of potato (Solanum tuberosum L.) breeding. The study was based on 90 progenies (72 crosses+18 selfs) evaluated for three successive generations, i.e. seedling, first clonal and second clonal generations. Repeatabilities of progeny means were measured as correlation coefficients between generations. In the univariate cross prediction method, progeny means and within-progeny standard deviations were used to calculate the proportions of clones exceeding the target values, and correlation coefficients between generations for predicted and observed proportions of clones, were calculated. Population means varied from generation to generation. Correlation coefficients between generations for progeny means for most of the characters were significant, but moderate. These were higher than the correlation coefficients between predicted and observed proportions of clones exceeding the target values. The possibility of using progeny means as a selection parameter to reduce the number of genotypes to be examined in later stages by rejecting the poor crosses in seedling generation is discussed. Received: 8 January 1997/Accepted: 28 February 1997     

Resveratrol Has No Effect on Lipoprotein Profile and Does Not Prevent Peroxidation of Serum Lipids in Normal Rats

Trans-resveratrol, one of the antioxidants found in red wine, has been the subject of controversial reports regarding its protective role against cardiovascular diseases. In this study we synthesized trans-resveratrol and injected it to rats (20 and 40 mg/kg body weight, once a day for 21 days, i.p.) to determine its effect on the serum lipid profile. Synthetic trans-resveratrol was an effective antioxidant in vitro against hydroxyl radical (I₅₀ = 33 μM). Resveratrol treatment, however, did not have any effect on either the lipid profile or on Cu⁺²-dependent formation of thiobarbi-turic-acid-reactive substances (TBARS) from protein-associated lipids. Since the amount of resveratrol used in these experiments was orders of magnitude higher than the amounts found in wine, these results suggest that if resveratrol has any effect against coronary heart diseases, it is not related to its antioxidant role on lipids or to changes in lipoprotein profile.     

Simultaneous quantitation of plasma doxorubicin and prochlorperazine content by high-performance liquid chromatography

A high-performance liquid chromatographic method has been developed and tested for simultaneous extraction, elution and determination of doxorubicin and prochlorperazine content in human plasma samples. The procedure consists of extraction through a conditioned C₁₈ solid-phase extraction cartridge, elution from a Spherisorb C₈ reversed-phase column by an isocratic mobile phase (60% acetonitrile, 15% methanol and 25% buffer) followed by detection with electrochemical and fluorescence detectors. Recovery of doxorubicin and prochlorperazine from pooled human plasma samples (n=3) containing 100 ng/ml of the two drugs was 77.8±3.5% and 89.1±6.0%, respectively. The lower limits of quantitation for doxorubicin and prochlorperazine in plasma samples were 6.25 ng/ml and 10 ng/ml, respectively. A linear calibration curve was obtained for up to 2 μg/ml of doxorubicin and prochlorperazine. This combination method may be of particular value in clinical studies where phenothiazines such as prochlorperazine are used to enhance retention of doxorubicin in drug resistant tumor cells.