RelA regulates virulence and intracellular survival of Francisella novicida.

Analysis of the genome of Francisella tularensis has revealed few regulatory systems, and how the organism adapts to conditions in different niches is poorly understood. The stringent response is a global stress response mediated by (p)ppGpp. The enzyme RelA has been shown to be involved in generation of this signal molecule in a range of bacterial species. We investigated the effect of inactivation of the relA gene in Francisella by generating a mutant in Francisella novicida. Under amino acid starvation conditions, the relA mutant was defective for (p)ppGpp production. Characterization showed the mutant to grow similarly to the wild-type, except that it entered stationary phase later than wild-type cultures, resulting in higher cell yields. The relA mutant showed increased biofilm formation, which may be linked to the delay in entering stationary phase, which in turn would result in higher cell numbers present in the biofilm and reduced resistance to in vitro stress. The mutant was attenuated in the J774A macrophage cell line and was shown to be attenuated in the mouse model of tularaemia, but was able to induce a protective immune response. Therefore, (p)ppGpp appears to be an important intracellular signal, integral to the pathogenesis of F. novicida.

Measuring appraisals following acquired spinal cord injury: a preliminary psychometric analysis of the appraisals of disability.

OBJECTIVES: The current study aimed to develop a reliable and valid appraisal scale (The Appraisals of DisAbility: Primary and Secondary Scale; ADAPSS) for adult spinal cord injury (SCI) populations. METHOD: Items for the ADAPSS were generated using themes and quotes from a qualitative study exploring appraisals made by individuals with SCI. The ADAPSS was administered with 2 additional appraisal measures, a measure of anxiety and depression, a measure of social desirability and demographic information. The study used a cross-sectional questionnaire design with a test-retest component, sampling community-based individuals with SCI. Data analysis was undertaken on 237 completed questionnaires. RESULTS: Factor analysis revealed the ADAPSS to have a 6-factor structure and the following subscales identified: (a) Fearful Despondency, (b) Overwhelming Disbelief, (c) Determined Resolve, (d) Growth and Resilience, (e) Negative Perceptions of Disability, and (f) Personal Agency. CONCLUSION: Preliminary analyses suggest the ADAPSS demonstrates reasonable reliability and validity and has potential as a therapeutic outcome measure. Future research should focus on the relationship between appraisals identified on the ADAPSS and their relationship to the coping strategies that individuals employ and adjustment to SCI. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Decreased Fc receptor expression on macrophages following simple hemorrhage as observed by scanning immunoelectron microscopy.

Although it is known that macrophage (M phi) functions such as phagocytosis and antigen presentation are depressed following hemorrhage and resuscitation, the mechanism remains unknown. The aim of this study was to determine, using scanning immunoelectron microscopic techniques, whether there is any alteration in the Fc receptors on the M phi after hemorrhage. To study this, male C3H/HeN mice were bled to a mean blood pressure (BP) of 35 mm Hg and maintained at that pressure for 1 hr, then resuscitated with their own blood and adequate fluids. Twenty-four hrs later, Kupffer cells from livers and splenic adherent cells were isolated, incubated for 16 hr, and then exposed to polysterene beads conjugated with antimouse IgG that specifically binds to Fc receptors. The cells were then prepared for observation by scanning electron microscopy. At least 100 cells from each animal were examined. The number of Kupffer cells from posthemorrhage mice that exhibited specific receptor labeling was significantly decreased (41.0 +/- 2.6, P less than 0.05) compared with control (64.2 +/- 7.5). The number of splenic adherent cells from posthemorrhage mice exhibiting specific receptor labeling was also significantly decreased (35.7 +/- 2.5, P less than 0.01) compared with control (61.2 +/- 3.9). The internalization of markers was also seen in some cells. The cause of the decrease in receptor labeling following hemorrhage may be the loss, inactivation, and/or internalization of receptors. Thus the decreased number of functional macrophages may contribute to the depression of antigen presentation and to the enhanced susceptibility to sepsis following hemorrhage.

Genomic typing of Escherichia coli O157:H7 by semi-automated fluorescent AFLP analysis.

Escherichia coli serotype O157:H7 isolates were analyzed using a relatively new DNA fingerprinting method, amplified fragment length polymorphism (AFLP). Total genomic DNA was digested with two restriction endonucleases (EcoRI and MseI), and compatible oligonucleotide adapters were ligated to the ends of the resulting DNA fragments. Subsets of fragments from the total pool of cleaved DNA were then amplified by the polymerase chain reaction (PCR) using selective primers that extended beyond the adapter and restriction site sequences. One of the primers from each set was labeled with a fluorescent dye, which enabled amplified fragments to be detected and sized automatically on an automated DNA sequencer. Three AFLP primer sets generated a total of thirty-seven unique genotypes among the 48 E. coli O157:H7 isolates tested. Prior fingerprinting analysis of large restriction fragments from these same isolates by pulsed-field gel electrophoresis (PFGE) resulted in only 21 unique DNA profiles. Also, AFLP fingerprinting was successful for one DNA sample that was not typable by PFGE, presumably because of template degradation. AFLP analysis, therefore, provided greater genetic resolution and was less sensitive to DNA quality than PFGE. Consequently, this DNA typing technology should be very useful for genetic subtyping of bacterial pathogens in epidemiologic studies.

Right ventricular--saphenous vein graft fistula. Unusual complication of aorta-coronary bypass grafting.

A fistula between the right ventricle and a saphenous vein graft aneurysm developed 10 years following aorta-coronary bypass. Surgical repair was attempted, but the autopsy finding of a large myocardial infarction raised the possibility of a "coronary steal" phenomenon.

Diltiazem administration after crystalloid resuscitation restores active hepatocellular function and hepatic blood flow after severe hemorrhagic shock.

Studies have shown that active hepatocellular function is depressed after hemorrhagic shock, despite crystalloid resuscitation. It is also known that calcium antagonists produce various beneficial effects on cell and organ function after ischemia and shock. However, it remains unknown whether such agents have any salutary effects on the depressed active hepatocellular function and hepatic blood flow in a nonheparinized model of trauma and hemorrhage. To study this, rats underwent a midline laparotomy (trauma-induced) and were bled to and maintained at a mean arterial pressure of 40 mm Hg until 40% of the maximum bleedout was returned in the form of Ringer's lactate. They were then resuscitated with four times the volume of shed blood with Ringer's lactate over 60 minutes, during and after which diltiazem (400 micrograms/kg body weight) was infused intravenously over 95 minutes. Active hepatocellular function (Vmax and Km) was determined with an in vivo indocyanine green clearance technique. Effective hepatic blood flow (EHBF) was determined by Fick principle and corrected by the indocyanine green extraction ratio. Hepatic microvascular blood flow (HMBF) was measured by laser Doppler flowmetry. Results indicate that Vmax, Km, EHBF, and HMBF decreased significantly at 1.5 and 4 hours after resuscitation. Diltiazem infusion restored the depressed Vmax, Km, EHBF, and HMBF and prevented the occurrence of hepatic edema. Thus, diltiazem may be a useful adjunct in the treatment of trauma and severe hemorrhage even in the absence of blood resuscitation.

Interferon-gamma attenuates hemorrhage-induced suppression of macrophage and splenocyte functions and decreases susceptibility to sepsis.

Although it is known that interferon-gamma synthesis and macrophage functions are depressed after hemorrhage, it remains to be determined whether systemic administration of interferon-gamma has any effect on hemorrhage-induced depression of macrophage and splenocyte functions. To study this, C3H/HEN mice were bled to a mean blood pressure of 35 mm Hg, maintained for 60 minutes, and followed by adequate fluid resuscitation. The mice then received either 1000 units interferon-gamma or saline solution (vehicle). Peritoneal (pM phi) and splenic (sM phi) macrophages and splenocytes were isolated 24 hours later. PM phi antigen presentation was measured by coculturing pM phi with the D10.G4.1 cell clone. Major histocompatibility complex class II (Ia) antigen expression was determined by direct immunofluorescence. Cytokine release by pM phi, sM phi, and splenocytes was assessed with specific bioassays. For survival studies, mice were subjected to sepsis 3 days after hemorrhage. Treatment with interferon-gamma restored (p less than or equal to 0.05) hemorrhage-induced suppression of pM phi antigen presentation capacity and Ia antigen expression and increased (p less than or equal to 0.05) interleukin-1 and tumor necrosis factor release by pM phi and sM phi, as well as splenocyte proliferation (p less than or equal to 0.05). Interferon-gamma also decreased (p less than or equal to 0.007) the susceptibility to sepsis after hemorrhage. Thus interferon-gamma represents a potent agent for treating hemorrhagic shock-induced immunosuppression and for increasing the ability of the host defense system to combat bacterial infections after hemorrhage.

Depressed antigen presentation function and membrane interleukin-1 activity of peritoneal macrophages after laparotomy.

Although major tissue trauma produces profound depression of cell-mediated immunity, it is not known whether surgical trauma (i.e., midline laparotomy) has any adverse effect on the antigen presentation function and membrane interleukin-1 (IL-1) activity of peritoneal macrophages. To study this, C3H/HEJ (endotoxin-tolerant) mice were anesthetized. An approximately 1-inch midline abdominal incision was made, followed by abdominal closure. On days 1, 3, 5, and 7, peritoneal macrophages were harvested by means of peritoneal lavage, and antigen presentation capability was tested by incubating various numbers of peritoneal macrophages with 2 X 10(4) D10.G4.1 cells per well in the presence of conalbumin (400 micrograms/ml). The T helper cell clone (D.10.G4.1) proliferates on recognition of conalbumin in the context of Iak and also proliferates in the presence of membrane-bound IL-1 plus concanavalin A. To measure membrane IL-1 expression in peritoneal macrophages, Concanavalin A (10 micrograms/ml) was substituted for conalbumin. Cultures were incubated for 72 hours, pulsed with tritiated thymidine, and harvested. Peritoneal macrophages from laparotomized mice induced significantly less T helper cell proliferation on days 1 and 3 in the antigen presentation assay (37% and 30%, respectively; p less than 0.05) and in the membrane IL-1 assay (14% and 10%, respectively; p less than 0.05) as compared with the control. This difference was not detectable on day 5. More effective antigen presentation capability (167% of control; p less than 0.05) was seen on day 7. Thus laparotomy by itself produces marked depression of both antigen presentation function and membrane IL-1 activity of peritoneal macrophages, which may enhance susceptibility to intra-abdominal sepsis.

Acute nonperforating appendicitis. Efficacy of brief antibiotic prophylaxis.

A prospective, randomized, double-blind clinical study was performed to determine the efficacy of perioperative systemic antibiotics in preventing infection after appendectomy for acute nonperforating appendicitis. One hundred three patients received three doses of either placebo (saline, n = 52) or cefoxitin sodium (n = 51). The two groups were similar with regard to age distribution, sex ratio, duration of operation, pathologic condition of appendix, and hospital stay. Postoperative wound infections were detected in 9.6% of the placebo-treated patients, whereas none occurred in the cefoxitin group. All but one infection appeared after discharge. Cost analysis identified a net savings of $ 84 per patient with the use of prophylactic antibiotics. Septic morbidity after appendectomy for nonperforating appendicitis is significantly reduced by systemic antibiotics, and brief administration of a single broad-spectrum agent (cefoxitin) is effective prophylaxis.

Effect of blood transfusion on antigen presentation function and on interleukin 2 generation.

To study the effect of blood transfusion (BT) on cell-mediated immunity, we examined the antigen presentation function of peritoneal macrophages and interleukin 2 (IL-2) generation by splenocytes. C3H/HEJ mice were transfused with 0.2 mL of fresh allogeneic blood obtained from C57BL/6 mice; they were killed on days 1, 3, and 7 after BT. A second group of C3H/HEJ mice was transfused with 0.2 mL/d of the same allogeneic blood on three successive days; they were killed on day 7 following the last BT. The antigen presentation function of peritoneal macrophages was measured by utilizing a D10.G4.1 T-helper cell clone; IL-2 activity in supernatants of concanavalin A-stimulated splenocytes was tested by utilizing an IL-2-dependent HT-2 cell line. The results indicate that although antigen presentation function remains unaffected after single and multiple BTs, the ability of splenocytes to generate IL-2 decreases significantly even after a single BT. Thus, the increased susceptibility to infection and the additional immune perturbations in malignant neoplasms following BT may be due in part to decreased IL-2 generation.

Can continuity-of-care requirements for surgery residents be demonstrated in the current teaching environment?

In 1994, the Residency Review Committee in Surgery began evaluating the ability of programs to provide adequate continuity-of-care experiences to residents, based on 6 criteria requiring resident participation in each phase of a surgical patient's care. The Residency Review Committee document further described resident and patient experiences as being synonymous. No previous studies were found that examined the 6 criteria or compared them with the patient's experience with continuity. Study objectives were 2-fold: (1) to assess the 6 required continuity-of-care experiences provided to general surgery residents and (2) to compare resident experiences to the patient's experience with continuity. Surgery residents from 2 academic years, representing each postgraduate year, were studied. Patients had (1) undergone an operation involving a resident and (2) remained hospitalized for longer than 24 hours but less than 10 days. Data were collected from a retrospective randomized review of each patient's medical records. Of the 114 cases, 23.7% showed that the same resident participated in all phases of care. In the remaining cases, residents provided preoperative care in 70.2%, directed the postoperative hospitalized care in 86.8%, and provided postdischarge care in 37.7%. Patients saw an average +/- SD of 4.6 +/- 1.5 surgical providers during the entire course of their surgical care. In conclusion, continuity experiences were provided to surgery residents in varying quantities and combinations, with one quarter of the residents experiencing "perfect continuity." Resident continuity experiences and patient continuity were not synonymous. Although improved medical record documentation may have enhanced these results, continuity-of-care remains difficult to demonstrate in view of the current surgery teaching environment.

Small-molecule selectin inhibitor protects against liver inflammatory response after ischemia and reperfusion.

BACKGROUND: The selectin family of adhesion molecules plays a key role in the neutrophil-mediated injury observed after ischemia and reperfusion. In our study, we investigated the effects of TBC-1269, a novel small-molecule, nonoligosaccharide inhibitor of P-, E-, and L-selectin binding, in the liver inflammatory response after 90 minutes of warm ischemia. STUDY DESIGN: Total liver ischemia was produced in Sprague-Dawley rats for 90 minutes using an extracorporeal portosystemic shunt. The animals were divided into five groups including: the sham (group 1), ischemic control (group 2) receiving only the vehicle, and the treated groups receiving TBC-1269 at a dose of 25 mg/kg at different times of administration: 15 minutes before reperfusion (group 3), at reperfusion (group 4), and 15 minutes after reperfusion (group 5). The following indices were analyzed: 7-day survival, liver injury tests, liver tissue myeloperoxidase as an index of neutrophil infiltration, and liver histology. RESULTS: TBC-1269 treated groups experienced a significant increase in survival compared with controls. Best overall survival, 70%, was observed when TBC-1269 (Texas Biotechnology Corporation, Houston, TX) was administered 15 minutes before reperfusion (p < 0.05). This group also showed a marked decrease (p < 0.05) in liver enzyme levels at 6 hours after reperfusion. Neutrophil migration was also significantly ameliorated (81%), as reflected by decreased myeloperoxidase levels. We observed improved histologic damage scores in the treated group compared with controls (p < 0.05). CONCLUSIONS: A small-molecule selectin inhibitor (TBC-1269) had a protective effect in livers subjected to 90 minutes of warm hepatic ischemia and 6 hours of reperfusion by decreasing neutrophil infiltration, migration and subsequent tissue damage. The best protective effect was achieved when the compound was administered 15 minutes before reperfusion. These findings offer a new therapeutic alternative for protection against ischemia and reperfusion injury.

Polytetrafluoroethylene versus autogenous vein grafts for vascular reconstruction in contaminated wounds.

A high incidence of dissolution and disruption of infected autogenous vein grafts has been demonstrated. PTFE, on the other hand, has been shown to maintain its structural integrity in the presence of well-entrenched infection, with a relatively small incidence of anastomotic disruption related to host artery necrosis. In addition, PTFE performed as well as autogenous vein when antibiotics were administered. Therefore, PTFE graft material is advocated for controlled clinical trials in patients with contaminated vascular injuries.

Thyroid cancer: diagnosis and management based on a review of 142 cases.

Review of 142 patients with thyroid cancer diagnosed and treated in a community hospital from 1958 through 1972 suggests that total thyroidectomy and radical neck dissection are unwarranted in the treatment of papillary carcinoma. Radioactive iodine scanning and needle biopsy are also shown to be unreliable indexes of malignancy. An operation approach to the management of specific thyroid cancers is presented.

Assessing energy requirements of patients on respirators.

This report documents a specific situation in which indirect calorimetry produced large overestimations of oxygen consumption and energy expenditure of a patient on a respirator. High positive-end expiratory pressures combined with high fractional concentrations of O2 led to perforation of lung parenchyma with considerable loss of O2, which produced subcutaneous emphysema and recurrent pneumothoraces. Typical calculations for determining energy expenditure from O2 consumption, therefore, could not be employed. Calculations utilizing the volume of CO2 expired, however, were less sensitive and variable during this time period. Resting energy expenditures were calculated from the volume of CO2 expired by using 5.52 kcal/l as the caloric equivalent of CO2. This procedure does not overestimate energy needs when a physiological gas leak exists (high positive-end expiratory pressures and high fractional concentrations of O2 or chest tube). This is very important in the ventilatory patient as excess carbohydrate can further stress the compromised pulmonary status.

Effect of enteral feeding bag composition and freezing and thawing upon vitamin stability in an enteral feeding solution.

The effect of enteral feeding bag composition and freezing and thawing upon the stability of riboflavin and vitamins A and E in an enteral feeding solution was tested. Feeding bags composed of either polyvinyl chloride or polyethylene were filled with an enteral feeding solution. The samples were frozen for 3 months, thawed in warm water, and allowed to stand in room temperature for 12 hr. Samples for vitamin analysis were obtained prior to freezing, upon thawing, and at 12 hr after thawing. No significant differences in vitamin stability due to bag composition or time were seen. These results support the viability of the concept of mixing large batches of enteral feeding solution, and freezing aliquots in individual feeding bags for later use.

Plasma vitamin and mineral status in home parenteral nutrition patients.

Home parenteral nutrition (HPN) provides long-term nutritional support for persons whose absorptive capacity is compromised by a variety of intestinal malabsorption problems. However, the presence of vitamin and mineral deficiency syndromes that normally would not have time to develop in the hospitalized patient receiving total parenteral nutrition has been reported in patients receiving HPN. This study entails a longitudinal survey of plasma concentrations of vitamins A, E, and 1,25-dihydroxyvitamin D, as well as the minerals zinc, copper, and selenium, in patients receiving HPN. Plasma samples from eight patients who had been on HPN for 1-92 months before the study began were obtained once a month over a 12-month period. The blood was drawn immediately before their evening infusion of TPN in order to approximate fasting plasma nutrient concentrations. Patient values were compared to fasting control values and to published norms. Values for vitamin A, 1,25-dihydroxyvitamin D, and zinc all were within the normal range, and there was no evidence of metabolic bone disease. Plasma vitamin E and copper concentrations exceeded the normal range for most of the 12-month period. Of all of the nutrients studied, only plasma selenium concentrations were consistently in the low-normal to below-normal range. Selenium levels in patients on HPN should be monitored regularly, and supplementation may be necessary if clinical conditions warrant.

Buffered hydrochloric acid: a modern method of treating metabolic alkalosis.

Twenty-one patients with metabolic alkalosis were treated successfully with intravenous hydrochloric acid (HCl) buffered in an amino acid solution (TPN). No complications of HCl were seen. TPN was used to meet energy needs and provide a buffering effect through the interaction of HCl and amino acids. Buffered HCl therapy should be considered as the initial treatment in patients with metabolic alkalosis associated with congestive heart failure, renal failure, hepatic failure, cerebral edema, or refractory metabolic alkalosis.

Percutaneous transhepatic cholangiography with a small-gauge needle: results of a two-year study in a community hospital.

Fifty patients in a community hospital underwent evaluation of the biliary system by the new small-gauge needle technique of percutaneous transhepatic cholangiography. The high success rate, ease of performance, and low complication rate attest to the worth of this procedure in the diagnosis of hepatobiliary disease.

Fibronectin. A new nutritional parameter.

Acute and chronic malnutrition is associated with increased morbidity and mortality in surgical patients. Plasma fibronectin levels have been shown to correlate with reticuloendothelial function and are reduced in burns, shock, trauma, and sepsis. Patients failing to show an increase in fibronectin levels after stress have been shown to do poorly. Starvation studies in human volunteers have demonstrated decreasing plasma fibronectin levels until feeding was resumed. The purpose of this study is to examine the usefulness of fibronectin as an assessment parameter in nutritionally depleted hospitalized patients. Eight patients initiated on parenteral nutrition were studied. Plasma fibronectin, albumin, and transferrin levels were drawn before TPN and repeated at various intervals after total parenteral nutrition (TPN) was begun. Mean pre-TPN transferrin was 198.1 +/- 16.1 gm/dl (nl 220-400). Transferrin levels remained statistically unchanged after 8 to 11 days of TPN. Mean pre-TPN albumin was 3.0 +/- 0.2 gm/dl (nl 3.6-4.8) and also remained statistically unchanged after 8 to 11 days of TPN. The mean fibronectin level pre-TPN was 236.4 +/- 24.4 microgram/ml (nl 370-410). Fibronectin rose statistically (P less than 0.005) after 1 to 4 days of TPN to a mean of 341.9 +/- 30.1 microgram/ml and remained elevated and statistically unchanged after 8 to 11 days of TPN. Six of the eight patients studied survived and had demonstrated at least a 30 per cent increase in fibronectin after 1 to 4 days of TPN. Both patients who died demonstrated minimal increase in fibronectin levels after 1 to 4 days of TPN.(ABSTRACT TRUNCATED AT 250 WORDS)