Effects of Simulated Hail Events and Subsequent Fungicide Applications on Cranberry Fruit Rot Incidence and Yield.

Storms containing hail are a common occurrence in Wisconsin, with a few or many cranberry (Vaccinium macrocarpon) growers being affected every year. Growers usually apply fungicides immediately following hail events to prevent fruit rot, despite a lack of research to support this practice. We conducted field trials in 2010 and 2011 to address the question of whether applying fungicides to injured fruit reduces fruit rot incidence (% rotten fruit). Hail damage was simulated by forcibly projecting pea gravel into cranberry beds using a mist-blower sprayer modified for this purpose, and the fungicides azoxystrobin or copper hydroxide were applied to fruit immediately after applying gravel. Fruit rot incidence and yield were evaluated within 2 weeks prior to commercial harvest in late September and early October. Fruit rot incidence was greater (P ≤ 0.05) and yield was lower (P < 0.05) in plots treated with gravel than in the nontreated control plots in six of seven trials. Fungicides did not reduce fruit rot incidence (P ≥ 0.05) in gravel-treated plots compared to the nontreated control in six of seven trials. However, in a trial conducted on relatively immature berries, fruit rot incidence in gravel-treated plots treated with azoxystrobin was less (P = 0.0103) than fruit rot incidence in gravel-treated plots receiving no fungicide treatment. In that same trial, fruit rot incidence was not reduced (P = 0.1243) in gravel-treated plots treated with copper hydroxide compared to gravel-treated plots that were not treated with fungicide. Results suggest that under most circumstances, if cranberries are damaged by hail, it is unlikely that an application of fungicide will reduce the amount of fruit rot at the time of harvest.

Repetitive acute pancreatic injury in the mouse induces procollagen alpha1(I) expression colocalized to pancreatic stellate cells.

Pancreatic stellate cells may be a major source of extracellular matrix deposition during injury. This study was undertaken to establish whether pancreatic stellate cells are a source of Type I collagen in vivo and whether they continue to be a source of matrix production in the post-injury fibrotic pancreas. To induce pancreatic fibrogenesis, acute pancreatic injury was induced in mice three times weekly with supraphysiologic doses of cerulein. Animals were treated for 6 weeks and allowed to recover for an additional 6 weeks. Stellate cell activation and pancreatic collagen expression were measured by immunohistochemistry, whole tissue RNA analysis, and in situ hybridization. Histology and digital image analysis demonstrated the development of substantial pancreatic fibrosis after 6 weeks of treatment. During recovery, incomplete resolution of the fibrosis was found. Procollagen alpha1(I) mRNA increased more than 15-fold during treatment and continued to be 5-fold elevated during the post-injury phase. In situ hybridization studies demonstrated that collagen gene expression was colocalized to activated pancreatic stellate cells. Collagen expression and fibrosis persisted in focal areas during recovery. These findings show that pancreatic stellate cells are the major source of collagen during repetitive injury in vivo. Additionally, focal areas of sustained pancreatic fibrogenesis persist after cessation of cerulein treatment, and these areas may contribute to sustained total organ collagen expression in the absence of ongoing injury.

Glutathione synthesis in the exocrine pancreas.

Glutathione is essential for cellular cytoprotection, and in the exocrine pancreas, it is required for digestive enzyme synthesis. The purpose of these studies was to measure the capacity of the exocrine pancreas to synthesize glutathione, determine whether the pancreatic transsulfuration pathway has a role in providing cysteine needed for glutathione synthesis, and determine whether the glutathione synthetic capacity of the pancreas responds to pathologically relevant stresses. The activity of gamma-glutamylcysteine synthetase, the key regulatory enzyme for glutathione synthesis, was 3.56 +/- 0.29 mU/mg protein in the pancreas of fed rats, compared to 31 +/- 4 in the liver and 116 +/- 5 in the kidney. Studies using dispersed rat pancreatic acinar cells showed that the exocrine pancreas synthesizes glutathione from precursor amino acids and that the transsulfuration pathway is functionally intact in the pancreas and may serve as an important source of pancreatic cysteine. In mice, pancreatic gamma-glutamylcysteine synthetase activity was induced 37% by corn oil, 77% by ethanol, and 88% by both treatments. Thus, the glutathione synthetic capacity of the pancreas is quantitatively less than that of the kidney or liver, but its key regulatory enzyme responds dynamically to pathologically relevant metabolic stresses, suggesting that glutathione is a key pancreatic cytoprotectant.

Cholestatic liver injury down-regulates hepatic glutathione synthesis.

Hepatocellular injury caused by cholestasis may be caused in part by oxidant stress. The purpose of this study was to establish how acute cholestasis might alter hepatic glutathione homeostasis and to determine whether injured hepatocytes are capable of reverting to normal glutathione homeostatic mechanisms. Acute cholestasis was achieved by surgical ligation of the common bile duct in rats. Bile duct ligation induced a 3.7-fold increase in hepatic glutathione content over 4 days. This increase was not due to increased hepatic activity of gamma-glutamylcysteine synthetase (GCS); on the contrary, whole-liver GCS activity was substantially diminished in the bile duct-ligated liver to 34 and 11% of normal after 4 and 7 days, respectively. To determine if hepatocytes removed from the cholestatic environment maintained these changes in glutathione homeostasis, hepatocytes were isolated from bile ductligated livers and established in primary culture. In cells isolated after 4 days of bile duct ligation, the elevated hepatocyte glutathione content decreased and the low GCS activity increased over 2 days in culture. More importantly, the ability of postcholestatic hepatocytes to substantially increase their glutathione synthetic capacity by increasing GCS activity in response to stress was preserved. This compensatory increase was due primarily to new protein synthesis. Together, these observations suggest that acute cholestasis impairs the ability of the liver to synthesize glutathione by down-regulating the key regulatory enzyme for its synthesis in response to acutely elevated glutathione levels and that the impaired glutathione synthetic capacity is corrected after cells are removed from the cholestatic environment.

Development of a new technique for reducing pressure pulse generation during 308-nm excimer laser coronary angioplasty.

Despite expectations that excimer laser ablation would result in a low incidence of coronary dissection, studies have documented a 15-20% incidence of dissection (including a 4-6% incidence of clinically significant dissection) during excimer interventions. This investigation sought to determine if pressure pulses produced by the exposure of fluid phase media (blood and contrast) to 308-nm excimer radiation might contribute to untoward outcomes. Pressure pulses generated in these media were quantitated to be > 100 atm. In vitro ablation of porcine aorta in the presence of blood or contrast resulted in tissue dissection, while ablation in pure crystalloid did not. Next, a "flush and bathe" technique designed to replace all blood and contrast with crystalloid was applied to a pilot population of 57 consecutive patients. There were no rhythm disturbances or laser-related clinically significant dissections in this group, and the clinical success rate was 95%. In summary, this report quantitates a potential etiology for excimer dissection and suggests that replacement of blood and contrast with crystalloid might improve procedural and clinical success rates.

Spitz's nevus in a "black" child of mixed ancestry.

The clinical and histologic features of a Spitz's nevus in a "black" child of mixed ancestry are described. The significance and rarity of this condition in phenotypically black individuals is commented upon.

Clinical significance of enterococci in blood cultures from adult patients.

The significance of enterococci in the blood cultures of 79 adult patients encountered in a 21-month period was reviewed by means of clinical data. One blood culture consisted of an aerobic and an anaerobic bottle. Patients were divided according to the clinical picture into those with "likely", "possible", and "dubious" septicemia. Those with "likely" septicemia showed significantly more positive sets and more often two positive bottles in a single set taken on the same day than patients in the other categories. They also grew cultures with shorter detection times, with 90% of all cultures eventually yielding enterococci within three days after collection. Finally, probability figures relating positivity in one or two bottles to detection time and category of significance are presented. They may be used prospectively to assess the chances of a blood cultures reflecting any of the three above categories.