Prophylactic antibiotics for severe acute pancreatitis: the beginning of an era

Death from acute severe pancreatitis results from infection and multiple organ system failure occurring late in the course of illness. Patients with necrotizing pancreatitis involving at least one-third of the organ are at highest risk of secondary infection and death. We conducted a MEDLINE search to identify human trials of prophylactic antibiotics in acute pancreatitis. Results of early studies of prophylactic ampicillin to avoid secondary infection and death were negative, but the studies included patients with mild disease who are at low risk for infection. Antibiotics were beneficial in four recently completed studies: imipenem significantly reduced pancreatic and nonpancreatic sepsis (p< or =0.01); cefuroxime reduced all infectious complications (p<0.01) and deaths (p=0.0284); a regimen of ceftazidime, amikacin, and metronidazole reduced all infectious complications (p<0.03); and protocol use of imipenem significantly reduced pancreatic infection compared with nonprotocol antibiotics (p=0.04) and no antibiotics (p<0.001). Based on these results, we suggest early antibiotic prophylaxis in patients with necrotizing pancreatitis, but the best drug and duration of therapy are unknown.

Liposome-mediated immunotherapy against respiratory influenza virus infection using double-stranded RNA poly ICLC

The use of liposome delivery technology to enhance the antiviral activity of poly ICLC (an immunomodulating dsRNA) while decreasing its intrinsic toxicity is evaluated in this study. The antiviral efficacies of free and liposome-encapsulated poly ICLC were evaluated and compared using a lethal respiratory influenza A virus infection in mice. The toxicity profiles of free and liposome-encapsulated poly ICLC were compared by determining the extent of hypothermia and loss in body weights in mice pretreated with these drugs. Poly ICLC was encapsulated in cationic liposomes prepared by the freeze drying method. To determine the antiviral efficacies of free and liposome-encapsulated poly ICLC, mice were intranasally pretreated with two doses of poly ICLC (free or liposomal, 1 mg/kg/dose) given 48 h apart. At various times post pretreatment, mice were intranasally challenged with 10 LD50 mouse-adapted influenza A/PR/8 (H1N1) virus. The survival rates of the mice were determined at day 14 post infected and compared to the untreated control mice. Results indicate mice pretreated with liposome-encapsulated poly ICLC within 3 weeks prior to virus challenge were completely protected (100% survival compared to 0% for the untreated control group, p < 0.001), while window of protection provided by free unencapsulated poly ICLC was 12 days. When the toxicity profiles of free and liposome-encapsulated poly ICLC were compared, it was found that hypothermia and body weight loss induced by poly ICLC were either completely mitigated or significantly reduced in mice given equivalent doses of poly ICLC in the liposome-encapsulated form. These results suggest that liposomes are an excellent drug carrier for poly ICLC, that liposome-encapsulated poly ICLC may provide a safe and effective immunotherapeutic approach for the prevention of respiratory influenza virus infections.

Spectrum of hantavirus infection: hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome

Hantaviruses chronically infect rodents without apparent disease, but when they are spread by aerosolized excreta to humans, two major clinical syndromes result: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Both diseases appear to be immunopathologic, and inflammatory mediators are important in causing the clinical manifestations. In HPS, T cells act on heavily infected pulmonary endothelium, and it is suspected that gamma interferon and tumor necrosis factor are major agents of a reversible increase in vascular permeability that leads to severe, noncardiogenic pulmonary edema. HFRS has prominent systemic manifestations. The retroperitoneum is a major site of vascular leak and the kidneys suffer tubular necrosis. Both syndromes are accompanied by myocardial depression and hypotension or shock. HFRS is primarily a Eurasian disease, whereas HPS appears to be confined to the Americas; these geographic distinctions correlate with the phylogenies of the rodent hosts and the viruses that coevolved with them.

Outcome after operations for pulmonary atresia with intact ventricular septum

OBJECTIVE

Pulmonary atresia with intact ventricular septum is an anatomically heterogeneous anomaly with a variety of surgical strategies possible. We sought to compare the outcome of patients with a single ventricle approach to those with a biventricular repair and to compare outcome of patients with coronary abnormalities to those with normal coronary arteries.

METHODS

A retrospective review of our surgical database revealed 67 patients with pulmonary atresia with intact ventricular septum operated on between 1981 and 1998. Patients were categorized on the basis of initial surgical strategy: strategy A, aortopulmonary shunt alone (n = 31); strategy B, right ventricular recruitment (n = 32); strategy C, heart transplantation (n = 4). Tricuspid valve size (Z-score) and coronary anatomy were determined. Right ventricular-coronary artery dependency was noted in 8 patients.

RESULTS

Overall actuarial survivals at 1, 5, and 8 years were 82%, 76%, and 76%. Mortality was highest in infancy (10 of 16 deaths). Outcome was equivalent for all 3 strategies. There was no difference in tricuspid valve size between survivors and nonsurvivors (mean Z-score -2.0 (2.5) vs -2.0 (1.9), P =.83). There was no difference in survival based on severity of coronary abnormality. Only one third of patients had a successful biventricular repair, and the tricuspid valve was significantly larger in these than in patients who had Fontan operation (mean Z-score -0.53 [1.6], range -3.5 to 1, versus mean Z-score -3.03 [2.7], range -5.5 to 0, P =.002).

CONCLUSIONS

Surgical outcome for patients born with pulmonary atresia with intact ventricular septum is satisfactory. The strategies of biventricular repair, single ventricle palliation, and heart transplantation allow for equal outcome among all anatomic subtypes.

Systemic inflammatory response syndrome treatment by powdered sorbent pheresis: the BioLogic-Detoxification Plasma Filtration System

Systemic inflammatory response syndrome (SIRS) is one of the most common causes of death in intensive care unit patients. The detoxification plasma filtration (DTPF) system (HemoCleanse, Inc., West Lafayette, IN) combines the DT hemodiabsorption system in series with a push-pull pheresis PF system (a suspension of powdered sorbents surrounding 0.5 microm plasma filter membranes). Bidirectional plasma flow (at 80-100 ml/min) across the PF membranes provides direct contact between plasma proteins and powdered sorbents, as well as clearance of cytokines (tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6) at a rate of 15-25 ml/min, without evidence of saturation for 90 minutes. In a U.S. Food and Drug Administration approved study we treated eight patients with SIRS and organ failure with a single DTPF treatment, using powdered charcoal as sorbent in four patients and powdered charcoal and silica in four patients. Treatments proceeded for 6 hours with proper heparin anticoagulation (activated clotting time 250-300 sec) and appeared safe. All patients improved during the treatments and each had increased blood pressure and decreased need for pressor agents. Plasma cytokine levels stabilized or decreased during treatment and were significantly lower the morning after treatment. Multiple organ dysfunction (MOD) and Acute Physiology Chronic Health Evaluation II scores and organ function gradually improved in most patients, and two patients survived for more than 28 days and two for more than 14 days. The DTPF System may prove beneficial in treatment of patients with sepsis.

3'-Processed mRNA is preferentially translated in Chlamydomonas reinhardtii chloroplasts

3'-end processing of nucleus-encoded mRNAs includes the addition of a poly(A) tail that is important for translation initiation. Since the vast majority of chloroplast mRNAs acquire their 3' termini by processing yet are not polyadenylated, we asked whether 3' end maturation plays a role in chloroplast translation. A general characteristic of the 3' untranslated regions of chloroplast mRNAs is an inverted repeat (IR) sequence that can fold into a stem-loop structure. These stem-loops and their flanking sequences serve as RNA 3'-end formation signals. Deletion of the Chlamydomonas chloroplast atpB 3' IR in strain Delta26 results in reduced accumulation of atpB transcripts and the chloroplast ATPase beta-subunit, leading to weakly photosynthetic growth. Of the residual atpB mRNA in Delta26, approximately 1% accumulates as a discrete RNA of wild-type size, while the remainder is heterogeneous in length due to the lack of normal 3' end maturation. In this work, we have analyzed whether these unprocessed atpB transcripts are actively translated in vivo. We found that only the minority population of discrete transcripts of wild-type size is associated with polysomes and thus accounts for the ATPase beta-subunit which accumulates in Delta26. Analysis of chloroplast rbcL mRNA revealed that transcripts extending beyond the mature 3' end were not polysome associated. These results suggest that 3'-end processing of chloroplast mRNA is required for or strongly stimulates its translation.

Cutaneous cryptococcosis mimicking basal cell carcinoma in a patient with AIDS

BACKGROUND

Cryptococcosis is an opportunistic infection caused by the encapsulated yeast Cryptococcus neoformans. This ubiquitous organism has emerged as a frequent finding in immunosuppressed patients, especially those with underlying malignancies, organ transplants, and the acquired immune deficiency syndrome (AIDS). Cutaneous manifestations of cryptococcosis occur in 10 to 15% of patients having systemic involvement. These skin lesions may simulate a variety of different disease entities.

METHODS

A case of crytococcosis mimicking a basal cell carcinoma is the subject of a case report presentation.

RESULTS

A case of cutaneous cryptococcosis mimicking basal cell carcinoma occurred in a patient with AIDS, who did not appear to have dissemination, but was treated aggressively to stem possible occult systemic disease.

CONCLUSION

Cutaneous crytococcosis may mimic other dermatologic disorders.

Nasogastric and nasoenteric feeding tubes

This article discusses the placement of nasogastric and nasoenteric feeding tubes using blind, pH, magnetic, sonagraphic, electromyogram, fluoroscopic, and endoscopic-assisted techniques. Bedside tests to ensure appropriate tube location are detailed. The complications of inappropriately-located tubes are listed, and methods to reduce adverse side effects are given.

The chloroplast atpA gene cluster in Chlamydomonas reinhardtii. Functional analysis of a polycistronic transcription unit

Most chloroplast genes in vascular plants are organized into polycistronic transcription units, which generate a complex pattern of mono-, di-, and polycistronic transcripts. In contrast, most Chlamydomonas reinhardtii chloroplast transcripts characterized to date have been monocistronic. This paper describes the atpA gene cluster in the C. reinhardtii chloroplast genome, which includes the atpA, psbI, cemA, and atpH genes, encoding the alpha-subunit of the coupling-factor-1 (CF1) ATP synthase, a small photosystem II polypeptide, a chloroplast envelope membrane protein, and subunit III of the CF0 ATP synthase, respectively. We show that promoters precede the atpA, psbI, and atpH genes, but not the cemA gene, and that cemA mRNA is present only as part of di-, tri-, or tetracistronic transcripts. Deletions introduced into the gene cluster reveal, first, that CF1-alpha can be translated from di- or polycistronic transcripts, and, second, that substantial reductions in mRNA quantity have minimal effects on protein synthesis rates. We suggest that posttranscriptional mRNA processing is common in C. reinhardtii chloroplasts, permitting the expression of multiple genes from a single promoter.

Double-blind randomised controlled trial of monoclonal antibody to human tumour necrosis factor in treatment of septic shock. NORASEPT II Study Group

BACKGROUND

Despite the availability of potent antibiotics and intensive care, mortality rates from septic shock are 40-70%. We assessed the safety and efficacy of murine monoclonal antibody to human tumour necrosis factor alpha (TNF alpha MAb) in the treatment of septic shock.

METHODS

In a randomised, multicentre, double-blind, placebo-controlled clinical trial in 105 hospitals in the USA and Canada, we randomly assigned 1879 patients a single infusion of 7.5 mg/kg TNF alpha MAb (n=949) or placebo (0.25% human serum albumin n=930). Our main outcome measurement was the rate of all-cause mortality at 28 days.

FINDINGS

382 (40.3%) of 948 patients who received TNF alpha MAb and 398 (42.8%) of 930 who received placebo had died at 28 days (95% CI -0.02 to 0.07, p=0.27). We found no association between therapy with TNF alpha MAb and increased rapidity in reversal of initial shock or prevention of subsequent shock. Similarly, baseline plasma interleukin-6 concentrations of more than 1000 pg/mL or detectable circulating TNF concentrations were not associated with improvement in survival after TNF alpha MAb therapy. Coagulopathy but not other organ or system failures, was significantly decreased in the TNF alpha MAb group compared with placebo (day 7, p<0.001; day 28, p=0.005). Serious adverse events were reported in 55.2% of patients given placebo and 54.1% in the TNF alpha MAb group.

INTERPRETATION

We did not find an improvement in survival after septic shock with TNF alpha MAb. Therapy not solely dependent on TNF alpha blockade may be required to improve survival.

Successful treatment of adults with severe Hantavirus pulmonary syndrome with extracorporeal membrane oxygenation

OBJECTIVE

To describe our experience with the use of extracorporeal membrane oxygenation (ECMO) as a rescue therapy in adult patients with severe cardiopulmonary failure from Hantavirus pulmonary syndrome.

DESIGN

Case series.

SETTING

Tertiary referral center.

PATIENTS

Patients with confirmed Hantavirus infection, who developed severe cardiopulmonary failure in which conventional therapy was assessed as being unsuccessful.

INTERVENTIONS

Records of previous patients treated for Hantavirus pulmonary syndrome were reviewed and findings consistent with 100% mortality were found.

MEASUREMENTS AND MAIN RESULTS

Findings associated with a 100% mortality rate were a) cardiac index of <2.5 L/min/m2; b) serum lactate concentration of >4.0 mmol/L (normal range 0.0 to 2.2); c) pulseless electrical activity or ventricular fibrillation or ventricular tachycardia; and d) refractory shock despite fluid resuscitation, and vasoactive medications. From 1994 to 1996, seven patients were admitted with confirmed Hantavirus pulmonary syndrome and severe cardiopulmonary failure. Three of the seven patients had at least two of the four criteria for a 100% mortality rate listed above, and appeared to be failing optimal conventional therapy. These three patients received support with venoarterial ECMO. The first patient was placed on ECMO during cardiac arrest and died. The next two patients who received ECMO for Hantavirus pulmonary syndrome survived after relatively short, uncomplicated ECMO runs, and were discharged without complications.

CONCLUSIONS

ECMO successfully provided cardiopulmonary support in two patients with severe Hantavirus pulmonary syndrome who survived with a good outcome. Our experience suggests that ECMO is a beneficial therapy for patients critically ill with Hantavirus pulmonary syndrome.

Pleural fluid characteristics in hantavirus pulmonary syndrome

Hantavirus pulmonary syndrome (HPS), is a rodent-borne, acute, often fulminant cardiorespiratory illness. Noncardiogenic pulmonary edema is prominent in HPS as is cardiac dysfunction. Pleural effusions are commonly noted in patients with HPS and have been thought to be exudative. This report describes the prevalence and characteristics of pleural effusions by an assessment of chest radiographs for the presence of pleural fluid and reviews all pleural fluid specimens obtained from patients with HPS. Of 23 patients treated at the University of New Mexico Hospital for HPS, 22 had evidence of pleural fluid while 4 had sampling of their pleural fluid. Two samples met criteria for an exudate by pleural fluid protein to serum protein ratio of more than 0.5; one was clearly a transudate and the other had inconsistent characteristics. The two exudative samples were obtained 7 days after admission, while the other 2 were obtained within 1 day of admission. Pleural fluid cultures were sterile, and the total of nucleated cells was less than 170/mm3, and predominately mononuclear. A hypothesis may be formulated that the pleural fluid in HPS is initially transudative, consistent with the observed cardiopulmonary dysfunction. However, following aggressive resuscitative efforts and as the acute illness resolves, fluid shifts occur as cardiac function normalizes; the pleural fluid may take on characteristics of an exudate.

Confirmatory interleukin-1 receptor antagonist trial in severe sepsis: a phase III, randomized, double-blind, placebo-controlled, multicenter trial. The Interleukin-1 Receptor Antagonist Sepsis Investigator Group

OBJECTIVE

To determine the therapeutic efficacy and safety of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) in the treatment of patients with severe sepsis.

DESIGN

Prospective, randomized, double-blind, placebo-controlled, multicenter trial with a planned, midstudy, interim analysis.

SETTING

Ninety-one academic medical center intensive care units in North America and Europe.

PATIENTS

Patients with severe sepsis or septic shock (n = 696) received standard supportive care and antimicrobial therapy for sepsis, in addition to rhIL-1ra or placebo.

INTERVENTIONS

Patients were randomized to receive either rhIL-1ra (100 mg) or placebo (vehicle) by intravenous bolus, followed by a 72-hr continuous intravenous infusion of either rhIL-1ra (2.0 mg/kg/hr) or placebo.

MEASUREMENTS AND MAIN RESULTS

The study was terminated after an interim analysis found that it was unlikely that the primary efficacy end points would be met. The 28-day, all-cause mortality rate was 33.1% (116/350) in the rhIL-1ra treatment group, while the mortality rate in the placebo group was 36.4% (126/346), yielding a 9% reduction in mortality rate (p = .36). The patients were well matched at the time of study entry; 52.9% of placebo-treated patients were in shock while 50.9% of rhIL-1ra-treated patients were in shock at the time of study entry (p = .30). The mortality rate did not significantly differ between treatment groups when analyzed on the basis of site of infection, infecting microorganism, presence of bacteremia, shock, organ dysfunction, or predicted risk of mortality at the time of study entry. No excess number of adverse reactions or microbial superinfections were attributable to rhIL-1ra treatment in this study.

CONCLUSIONS

A 72-hr, continuous intravenous infusion of rhIL-1ra failed to demonstrate a statistically significant reduction in mortality when compared with standard therapy in this multicenter clinical trial. If rhIL-1ra treatment has any therapeutic activity in severe sepsis, the incremental benefits are small and will be difficult to demonstrate in a patient population as defined by this clinical trial.

A Nuclear Mutation That Affects the 3[prime] Processing of Several mRNAs in Chlamydomonas Chloroplasts

We previously created and analyzed a Chlamydomonas reinhardtii strain, [delta]26, in which an inverted repeat in the 3[prime] untranslated region of the chloroplast atpB gene was deleted. In this strain, atpB transcripts are unstable and heterogeneous in size, and growth is poor under conditions in which photosynthesis is required. Spontaneous suppressor mutations that allow rapid photosynthetic growth have been identified. One strain, [delta]26S, retains the atpB deletion yet accumulates a discrete and stable atpB transcript as a consequence of a recessive nuclear mutation. Unlike previously isolated Chlamydomonas nuclear mutations that affect chloroplast mRNA accumulation, the mutation in [delta]26S affects several chloroplast transcripts. For example, in the atpA gene cluster, the relative abundance of several messages was altered in a manner consistent with inefficient mRNA 3[prime] end processing. Furthermore, [delta]26S cells accumulated novel transcripts with 3[prime] termini in the petD-trnR intergenic region. These transcripts are potential intermediates in 3[prime] end processing. In contrast, no alterations were detected for petD, atpA, or atpB mRNA 5[prime] ends; neither were there gross alterations detected for several other mRNAs, including the wild-type atpB transcript. We suggest that the gene identified by the suppressor mutation encodes a product involved in the processing of monocistronic and polycistronic messages.

Treatment of severe systemic inflammatory response syndrome and sepsis with a novel bradykinin antagonist, deltibant (CP-0127). Results of a randomized, double-blind, placebo-controlled trial. CP-0127 SIRS and Sepsis Study Group

OBJECTIVE

To test the effect of a novel bradykinin antagonist, deltibant (CP-0127), on survival, organ dysfunction, and other outcomes in patients with the systemic inflammatory response syndrome (SIRS) and presumed sepsis.

DESIGN

Multicenter, randomized, placebo-controlled, double-blind, parallel, dose-ranging trial. Follow-up for 28 days or until death.

SETTING

A total of 47 US referral hospitals.

PATIENTS

A total of 504 patients with SIRS and documented evidence of infection plus either hypotension or dysfunction of 2 organ systems.

INTERVENTIONS

Three-day continuous intravenous infusion of either placebo or 1 of 3 doses (0.3, 1.0, or 3.0 microg x kg(-1) x min(-1)) of deltibant. Concurrent therapy at the discretion of the treating physician.

MAIN OUTCOME MEASURE

Risk-adjusted, 28-day, log-normal intent-to-treat survival analysis. Risk adjustment was performed using a study-specific risk model derived from the APACHE III database.

RESULTS

Deltibant had no significant effect on risk-adjusted 28-day survival. In a posthoc analysis, risk-adjusted 7-day survival showed a nonsignificant trend toward improvement (P=.09). The 28-day risk-adjusted survival in the prospectively defined subset of patients with gram-negative infections showed a statistically significant improvement (P=.005).

CONCLUSIONS

Deltibant may have some effect on survival in patients with SIRS and gram-negative sepsis; however, additional studies would be required to prove this.