Regional and age-specific patterns of pandemic H1N1 influenza virus seroprevalence inferred from vaccine clinical trials, August-October 2009.

The extent of the H1N1 pandemic has been estimated from case counts and deaths but the proportion of exposed populations with inapparent infections has not been described in detail. We analysed haemagglutination-inhibition (HI) antibody titres of pre-vaccination sera from pandemic vaccine trials conducted in six countries on four continents to provide an indication of A/CA/07/2009(H1N1)-like influenza seroprevalence in those populations. Among 7,962 subjects, ranging in age from 12 months to over 60 years, the proportions with HI antibody titres > or =40 to the H1N1pnd virus in the period from August to October 2009 were, by country: Costa Rica 26.4%, United States (US) 22.5%, Switzerland 16.9%, Germany 12.6%, Belgium 10.1%, and Japan 5.9%. Age-specific seropositivity rates in the samples were higher in children and adolescents in Costa Rica and in the US than in Europe and in Japan. The low proportion of seropositive children in Europe and Japan suggests that little local viral transmission had occurred in those regions even as late as September and October 2009, while in the US and Costa Rica, the greater proportion of previously infected children and young adults suggested that a significant number of asymptomatic infections had occurred during the first pandemic wave. Nevertheless, in all locations, the majority of the population remained susceptible to the pandemic virus at the beginning of the influenza season in the northern hemisphere, justifying the implementation of public health interventions.

Increase in survival of liver grafts after rinsing with warm Ringer's solution due to improvement of hepatic microcirculation.

Temperature increases membrane fluidity and decreases vascular resistance in isolated organs. Therefore, these studies were designed to determine if a rinse with warm buffer could increase survival time in the rat model of orthotopic liver transplantation by improving hepatic microcirculation. Brief periods of warm ischemia (3-8 min) did not damage the liver as indexed by minimal release of LDH. Survival of rats for 30 days was greater than 90% in this model when livers were stored for 1 hr in Ringer's solution; yet grafts stored for 8 hr in Euro-Collins solution and rinsed with 20 ml of cold (0-4 degrees C) Ringer's solution survived postoperatively only around 3 days. However, livers stored for 8 hr in Euro-Collins and rinsed with 20 ml of warm (37 degrees C) Ringer's survived longer than 30 days (i.e., permanently). Serum transaminase levels reached peak values around 6000 U/L one day postoperatively in the cold-rinsed group, and liver injury assessed histologically was substantial. Under these conditions, pulmonary infiltration of inflammatory cells was observed in about 23% of lung tissue examined and was associated with massive bleeding. Following a warm rinse, however, maximal SGOT levels and injury to both liver and lung were reduced significantly by 80-90% 24 hr postoperatively. Moreover, the warm rinse improved hepatic microcirculation. It accelerated blood flow into the liver approximately two-fold, as indexed by the half-time of changes in hemoglobin reflectance from the liver surface, improved the distribution of colloidal carbon in the organ observed macroscopically, and decreased vascular resistance by over 50%. These data support the hypothesis that a brief rinse of liver grafts with warm buffer markedly improves the hepatic microcirculation, leading to dramatic improvement in graft survival. This work demonstrates clearly that a brief warm rinse may be useful clinically in liver transplantation.

Evidence that adenosine is a key component in Carolina rinse responsible for reducing graft failure after orthotopic liver transplantation in the rat.

Recently, a rinse solution, Carolina rinse, designed to minimize reperfusion injury following liver transplantation in the rat has been developed. When used to rinse cold-stored grafts prior to completion of implantation surgery, Carolina rinse improved postoperative survival dramatically. Here we report the results of studies designed to determine the key components of Carolina rinse. Livers were explanted, stored for 12 hr in cold UW solution (0-4 degrees C), and rinsed with 15 ml of Ringer's solution immediately prior to completion of implantation surgery. In this group, 12/13 rats died within 2 days (nonsurvival conditions). In a second group, explants stored under identical conditions were rinsed with 15 ml of Carolina rinse. Carolina rinse increased average 30-day survival time significantly to over 75%. Furthermore, when grafts were rinsed with Carolina rinse lacking nicardipine or with the pH increased to 7.4, long-term survival of recipient rats was also about 75% (i.e., the modifications did not affect survival). However, Carolina rinse lost its efficacy (12% survival) when adenosine was omitted. In addition, when donor livers were rinsed with Ringer's solution containing adenosine (0.1 mM), average survival time was increased from 8% to 63%. Rinsing with Ringer's solution containing higher concentrations of adenosine (5 mM), however, did not improve survival significantly. Survival was also not improved by rinsing with Ringer's containing 0.1 mM ribose and 0.1 mM adenine, substrates for ATP synthesis that are not vasoactive. SGOT values were around 3000 U/L 1-3 days postoperatively in the nonsurviving group rinsed with Ringer's solution alone. Values were decreased over 6-fold by Carolina rinse but were not reduced significantly by Ringer's solution containing adenosine. Thus, adenosine improves survival following liver transplantation without preventing parenchymal cell injury, indicating that adenosine may work via nonhepatic mechanisms. Liver injury was also assessed by electron microscopy. After either adenosine or Ringer's rinse, sinusoidal thrombi and polymorphonuclear margination were observed together with a pattern of pericentral hepatocellular vacuolization and disruption of the sinusoidal lining characteristic of changes observed following hypoxia. With Ringer's rinse, Kupffer cells exhibited surface irregularity in pericentral regions indicative of activation. Following adenosine rinse, however, Kupffer cells appeared more flattened with less ruffling and reduced surface debris (i.e., they were less activated). Carbon uptake by Kupffer cells was also decreased significantly by Ringer's rinse when adenosine was present. Furthermore, adenosine lowered intracellular free calcium concentration in cultured Kupffer cells and improved hepatic microcirculation postoperatively. Adenosine rinse also affected extrahepatic systems: it reduced postoperative clotting time and diminished lung injury significantly.(ABSTRACT TRUNCATED AT 400 WORDS)

Carolina rinse solution--a new strategy to increase survival time after orthotopic liver transplantation in the rat.

Recently, we described a new solution, Carolina rinse, that prevents nonparenchymal cell injury in vitro after reperfusion of livers stored in University of Wisconsin cold solution (Currin RT, Toole JG, Thurman RG, Lemasters JJ. Transplantation 1990; 50: 1076). The present study was designed to examine the effect of Carolina rinse on graft survival in vivo. Unlike UW cold storage solution, which is high in potassium, Carolina rinse contains extracellular inorganic ions at levels similar to blood, a calcium channel blocker and a radical scavenger. Carolina rinse also contains fructose and mildly acidotic pH to reduce hypoxic cell death. Livers from Lewis rats were explanted, stored in UW cold storage solution under nonsurvival conditions, and rinsed with either 15 ml of Ringer's, UW solution, Carolina rinse, or Carolina rinse saturated with nitrogen prior to completion of implantation surgery. In the Ringer's rinse group, only 4% of recipients survived 30 days postoperatively. In this group, SGOT levels reached maximal values of about 5000 U/L. Survival was also poor (25%) when grafts were rinsed with UW solution. In the Carolina rinse group, however, 9 of 16 rats (56%) survived indefinitely, and maximal postoperative SGOT levels were reduced 3-fold. Liver injury indexed histologically was also decreased about 3-fold by Carolina rinse compared with the control group rinsed with Ringer's solution. Carolina rinse diminished postoperative sinusoidal endothelial cell damage assessed by electron microscopy and reduced carbon particle phagocytosis due to Kupffer cells significantly. Moreover, Carolina rinse diminished graft swelling and improved postoperative hepatic microcirculation compared with the Ringer's rinse group. Taken together, these results indicate that Carolina rinse is a superior alternative to Ringer's solution in vivo to protect liver grafts from reperfusion injury when removing high-potassium-containing cold storage solutions clinically prior to implantation.

Evaluation and management of pediatric urinary tract infections.

Urinary tract infections (UTIs) are relatively common in children. We describe the evaluation and management of children with UTIs, as well as the risks and consequences related to the UTI. This article describes a rational approach to the evaluation and management of childhood UTIs with the relation to the natural history and risk factors.

Effect of contrast material on transitional cell carcinoma viability.

OBJECTIVES: To assess the effects of contrast material on the viability of transitional cell carcinoma (TCC) cells and the ability of such cells to attach to a recipient bed, because seeding of TCC into the upper urinary tract is a possibility during retrograde pyelography or percutaneous procedures. METHODS: Primary cultures of TCC cells were established and placed in either quarter, half, or full-strength contrast for 10 minutes or one-quarter strength contrast for 10, 30, and 60 minutes. Cells were then removed from the contrast agent, resuspended in urothelium-specific media, and incubated for 5 days, after which the cells were counted. RESULTS: A pronounced decrease in cell viability was observed with increasing exposure time and contrast material concentration. Cells incubated for 10, 30, and 60 minutes with contrast yielded an average of 79%, 60%, and 12% of the control group growth, respectively (P <0.001). Likewise, plates incubated with quarter, half, and full-strength contrast yielded 79%, 27%, and 10% of the control group growth, respectively (P <0.001). The difference in the response of low-grade superficial and high-grade invasive bladder tumors was not statistically significant. CONCLUSIONS: TCC cells that have been exposed to dilute contrast material for a short period are able to attach and grow on an adequate recipient bed. However, increasing the contrast concentration and/or the exposure time appears to decrease the viability and adherence of the TCC cells.

Bacteremia and bacteriuria after transrectal ultrasound guided prostate biopsy.

PURPOSE: We determined the incidence and predisposing factors of bacteremia and bacteriuria after prostate biopsy with specific emphasis on the value of a pre-biopsy enema. MATERIALS AND METHODS: We randomized 50 men undergoing ultrasound and biopsy to rule out prostate cancer to receive a preoperative (25) or no (25) enema. Preoperatively urine was obtained for culture, and questionnaires regarding urological history and voiding symptoms were completed. The initial prostate biopsy, biopsy needle, and postoperative urine and blood specimens were cultured. The following day a symptom questionnaire was completed. RESULTS: Bacterial growth in post-procedure cultures did not correlate with the number of biopsies, prostate specific antigen, obstructive voiding symptoms, prostate volume, cancer or post-biopsy hematuria. Bacteriuria was noted in 44% of the cases and bacteremia was present in 16% of the patients, of whom 87.5% did not receive an enema (p = 0.0003). Only 1 patient had chills and fever greater than 37.5C, requiring additional antibiotics. On the followup questionnaire 12% of patients described dysuria, including 84% with bacteriuria after biopsy. CONCLUSIONS: Bacteremia and bacteriuria after multiple biopsies are common but usually asymptomatic. Bacteria is apparently introduced into the urine and/or blood from the rectum via the biopsy needle, which may be minimized by a pre-biopsy enema. Dysuria or a history of urinary tract infection did not predict problems after biopsy.

Methyl palmitate prevents Kupffer cell activation and improves survival after orthotopic liver transplantation in the rat.

The purpose of this study was to determine whether prevention of Kupffer cell activation following orthotopic liver transplantation improves postoperative survival. First, particle phagocytosis by Kupffer cells was monitored continuously from the uptake of colloidal carbon by the perfused liver. Unstored livers took up carbon at rates of around 150 mg/g per hour, whereas storage for 24 h in Euro-Collins solution nearly doubled values to about 290 mg/g per hour. Treatment of rats with methyl palmitate, an inhibitor of phagocytosis by Kupffer cells, reduced carbon uptake to about one-third to one-half of control values in unstored and stored livers, respectively. Oxygen uptake, which was increased about 25% in stored and unstored livers by infusion of colloidal carbon, was only increased 5%-10% in both groups following treatment with methyl palmitate, suggesting that Kupffer cell activation was prevented by methyl palmitate. In livers transplanted after storage for 6 h in Euro-Collins solution (nonsurvival conditions), control rats survived only about 12 h, while treatment with methyl palmitate increased survival time significantly--more than threefold--to about 40 h. These data are consistent with the hypothesis that activation of Kupffer cells following cold ischemic storage and reperfusion is an early event involved in liver graft failure.

Effect of circumcision on prostatic bacterial colonization and subsequent bacterial seeding following transrectal ultrasound-guided prostate biopsies.

PURPOSE: This study was designed to compare the prevalence of prostatic bacterial growth between circumcised and uncircumcised males and determine whether the lack of circumcision results in a change in the incidence of bacterial seeding following prostate needle biopsy. MATERIALS AND METHODS: Forty-six men (21 circumcised and 25 uncircumcised) undergoing ultrasound and biopsy to rule out prostate cancer were evaluated with questionnaires regarding previous history of urinary tract infection (UTI), any symptoms suggestive of UTI, and obstructive voiding symptoms. None of the patients received preprocedure antibiotics. Preprocedure and postprocedure urine samples, prostate biopsy core, and postprocedure blood samples were obtained for culture. After the cultures were obtained, patients received oral antibiotics. RESULTS: Patient characteristics between circumcised and uncircumcised patients were similar in terms of age, prostate-specific antigen level, voiding symptoms, history of UTI, prostate biopsy technique, and incidence of prostate cancer. The prevalence of preprocedure bacteriuria was slightly higher in the uncircumcised men (14 [56%] of 25 patients) vs. the circumcised men (8/21 [38%] patients), although this was not statistically significant (r = .2, p = .1). The prevalence of postprocedure bacteriuria was significantly higher (p = .04) in the uncircumcised men (12/25 [48%] patients) vs. the circumcised men (4/21 [19%] patients). No correlation was found between circumcision status and incidence of bacterial colonization in the prostate tissue. A statistically significant difference (p = .003) was found between the lack of circumcision and postprocedure bacteremia. CONCLUSIONS: Circumcision status does not effect the prevalence of bacterial growth in the urine and the prostate tissue. Uncircumcised men have a higher incidence of bacteriuria and bacteremia following prostate needle biopsies.

Activation of Kupffer cells on reperfusion following hypoxia: particle phagocytosis in a low-flow, reflow model.

Hypoxia is produced selectively in pericentral regions of the liver lobule with a low-flow, reflow perfusion model in which the flow rate is reduced to approximately one-third to one-fourth of normal. This model was used to monitor carbon particle phagocytosis by Kupffer cells during hypoxia and reoxygenation. At normal flow rates, oxygen uptake was 131 mumol.g-1.h-1, pressure was 7.5 cmH2O, and carbon uptake was 150 mg.g-1.h-1. During the low-flow period, oxygen uptake, pressure, and carbon uptake decreased to values of 54 mumol.g-1.h-1, 6.4 cmH2O and 83 mg.g-1.h-1, respectively. Upon reflow, oxygen uptake and pressure increased to 141 mumol.g-1.h-1 and 10.3 cmH2O, respectively. In addition, carbon uptake was elevated approximately threefold to 234 mg.g-1.h-1, indicating activation of Kupffer cells. This activation was prevented by pretreatment with methyl palmitate, a known inhibitor of Kupffer cells. Histological examination revealed significantly more Kupffer cells laden with carbon particles in untreated livers after reflow than in livers from methyl palmitate-treated or untreated rats. Electron microscopic analysis of livers at reflow revealed Kupffer cells with numerous pseudopodia and lamellapodia, reflecting an activated state. These changes were absent in controls or in livers perfused under low-flow conditions. This study demonstrates that Kupffer cells are activated on reoxygenation after hypoxia.

A new method to monitor Kupffer-cell function continuously in the perfused rat liver. Dissociation of glycogenolysis from particle phagocytosis.

In order to study particle phagocytosis and glycogenolysis simultaneously, this study was designed to develop a direct-read-out method to monitor Kupffer-cell function continuously, based on the uptake of colloidal carbon by the isolated perfused rat liver. Livers were perfused for 20 min with Krebs-Henseleit buffer saturated with O2/CO2 (19:1). Colloidal carbon (1-2 mg/ml) was added to the buffer, and absorbance of carbon was monitored continuously at 623 nm in the effluent perfusate. Since colloidal-carbon uptake was proportional to A623, rates of uptake were determined from the influent minus effluent concentration difference, the flow rate and the liver wet weight. Rates of colloidal-carbon uptake were 50-200 mg/h per g and were proportional to the concentration of carbon infused. Data from light-microscopy and cell-separation studies demonstrated that carbon was taken up exclusively by non-parenchymal cells and predominantly by Kupffer cells. Further, the amount of colloidal carbon detected histologically in non-parenchymal cells increased as the concentration of colloidal carbon in the perfusate was elevated. When Kupffer cells were activated or inhibited by treatment with endotoxin or methyl palmitate, carbon uptake was increased or decreased respectively. Taken together, these results indicate that Kupffer-cell function can be monitored continuously in a living organ. This new method was utilized to compare the time course of phagocytosis of carbon by Kupffer cells and carbohydrate output by parenchymal cells. Carbohydrate output increased rapidly by 69 +/- 9 mumol per g within 2-4 min after addition of carbon and returned to basal values within 12-16 min. However, carbon uptake by the liver did not reach maximal rates until about 15 min. Infusion of a cyclo-oxygenase inhibitor, aspirin (10 mM), caused a progressive decrease in carbohydrate output and blocked the stimulation by carbon completely. Aspirin neither altered rates of carbon uptake nor prevented stimulation of carbohydrate release by addition of N2-saturated buffer. The data from these experiments are consistent with the hypothesis that output of mediators by Kupffer cells, presumably prostaglandin D2 and E2, occurs transiently as Kupffer cells begin to phagocytose foreign particles in the intact organ, a process which continues at high rates for hours.