MLKL overexpression leads to Ca2+ and metabolic dyshomeostasis in a neuronal cell model

The necroptotic effector molecule MLKL accumulates in neurons over the lifespan of mice, and its downregulation has the potential to improve cognition through neuroinflammation, and changes in the abundance of synaptic proteins and enzymes in the central nervous system. Notwithstanding, direct evidence of cell-autonomous effects of MLKL expression on neuronal physiology and metabolism are lacking. Here, we tested whether the overexpression of MLKL in the absence of cell death in the neuronal cell line Neuro-2a recapitulates some of the hallmarks of aging at the cellular level. Using genetically-encoded fluorescent biosensors, we monitored the cytosolic and mitochondrial Ca2+ levels, along with the cytosolic concentrations of several metabolites involved in energy metabolism (lactate, glucose, ATP) and oxidative stress (oxidized/reduced glutathione). We found that MLKL overexpression marginally decreased cell viability, however, it led to reduced cytosolic and mitochondrial Ca2+ elevations in response to Ca2+ influx from the extracellular space. On the contrary, Ca2+ signals were elevated after mobilizing Ca2+ from the endoplasmic reticulum. Transient elevations in cytosolic Ca2+, mimicking neuronal stimulation, lead to higher lactate levels and lower glucose concentrations in Neuro-2a cells when overexpressing MLKL, which suggest enhanced neuronal glycolysis. Despite these alterations, energy levels and glutathione redox state in the cell bodies remained largely preserved after inducing MLKL overexpression for 24-48 h. Taken together, our proof-of-concept experiments are consistent with the hypothesis that MLKL overexpression in the absence of cell death contributes to both Ca2+ and metabolic dyshomeostasis, which are cellular hallmarks of brain aging.

Gut resident Escherichia coli profile predicts the eighteen-month probability and antimicrobial susceptibility of urinary tract infections

Background

Community-acquired UTI is the most common bacterial infection managed in general medical practice that can lead to life-threatening outcomes. While UTIs are primarily caused by Escherichia coli colonizing the patient's gut, it is unclear whether the gut resident E. coli profiles can predict the person's risks for UTI and optimal antimicrobial treatments. Thus, we conducted an eighteen-month long community-based observational study of fecal E. coli colonization and UTI in women aged 50 years and above.

Methods and Findings

We enrolled a total of 1,804 women distributed among age groups 50-59 yo (437 participants), 60-69 yo (632), 70-79 yo (532), and above 80 yo (203), lacking antibiotic prescriptions for at least one year. The provided fecal samples were plated for the presence of E. coli and other enterobacteria resistant to trimethoprim/sulfamethoxazole (TMP/STX), ciprofloxacin (CIP) and 3rd generation cephalosporins (3GC). E. coli was also characterized as belonging to the pandemic multi-drug resistant clonal groups ST131 (subclone H30) and ST1193. Following sample collection, the women were monitored for 18 months for occurrence of UTI.E. coli was cultured from 90.8% fecal samples, with 24.1% containing bacteria resistant to TMP/STX, 19.4% to CIP, and 7.9% to 3GC. In 62.5% samples, only all-susceptible E. coli were present. Overall, there were no age-related differences in resistance prevalence. However, while the total E. coli H30 and ST1193 carriage rates were similar (4.3% and 4.2%, respectively), there was a notable increase of H30 carriage with age (P = .001), while carriage decreased with age for ST1193 (P = .057).Within 18 months, 184 women (10.2%) experienced at least one episode of UTI - 10.9% among the gut E. coli carriers and 3.0% among the non-carriers (P=.0013). The UTI risk among carriers of E. coli H30 but not ST1193 was significantly above average (24.3%, P = .0004). The UTI probability increased with age, occurring in 6.4% of 50-59 yo and 19.7% of 80+ yo (P<.001), with the latter group being especially at high risk for UTI, if they were colonized by E. coli H30 (40.0%, P<.001).E. coli was identified in 88.1% of urine samples, with 16.1% resistant to TMP/STX, 16.1% to CIP, 4.2% to 3GC and 73.1% to none of the antibiotics. Among tested urinary E. coli resistant to antibiotics, 86.1% matched the resistance profile of E. coli in the fecal samples, with the clonotyping and whole genome sequencing confirming the matching strains' identity. Positive predictive value (PPV) of using gut resistance profiles to predict UTI pathogens' susceptibility to TMP/STX, CIP, 3GC and all three antibiotics were 98.4%, 98.3%, 96.6% and 95.3%, respectively. Corresponding negative predictive values (NPV) were 63.0%, 54.8%, 44.4% and 75.8%, respectively. The AUC ROC curve values for the accuracy of fecal diagnostic testing for the prediction of UTI resistance ranged .86-.89. The fecal test-guided drug-bug mismatch rate for empirical (pre-culture) prescription of TMP-SXT or CIP is reduced to ≤2% in 89.6% of patients and 94.8% of patients with an optional 3GC prescription.

Conclusion

The resistance profile and clonal identity of gut colonizing E. coli, along with the carrier's age, can inform personalized prediction of a patients' UTI risk and the UTI pathogen's antibiotic susceptibility within an 18-month period.

Increase in the community circulation of ciprofloxacin-resistant Escherichia coli despite reduction in antibiotic prescriptions

BACKGROUND

Community circulating gut microbiota is the main reservoir for uropathogenic Escherichia coli, including those resistant to antibiotics. Ciprofloxacin had been the primary antibiotic prescribed for urinary tract infections, but its broad use has been discouraged and steadily declined since 2015. How this change in prescriptions affected the community circulation of ciprofloxacin-resistant E. coli is unknown.

METHODS

We determined the frequency of isolation and other characteristics of E. coli resistant to ciprofloxacin in 515 and 1604 E. coli-positive fecal samples collected in 2015 and 2021, respectively. The samples were obtained from non-antibiotic-taking women of age 50+ receiving care in the Kaiser Permanente Washington healthcare system.

RESULTS

Here we show that despite a nearly three-fold drop in the prescription of ciprofloxacin between 2015 and 2021, the rates of gut carriage of ciprofloxacin-resistant E. coli increased from 14.2 % to 19.8% (P = .004). This is driven by a significant increase of isolates from the pandemic multi-drug resistant clonal group ST1193 (1.7% to 4.2%; P = .009) and isolates with relatively few ciprofloxacin-resistance determining chromosomal mutations (2.3% to 7.4%; P = .00003). Though prevalence of isolates with the plasmid-associated ciprofloxacin resistance dropped (59.0% to 30.9%; P = 2.7E-06), the isolates co-resistance to third generation cephalosporins has increased from 14.1% to 31.5% (P = .002).

CONCLUSIONS

Despite reduction in ciprofloxacin prescriptions, community circulation of the resistant uropathogenic E. coli increased with a rise of co-resistance to third generation cephalosporins. Thus, to reduce the rates of urinary tract infections refractory to antibiotic treatment, greater focus should be on controlling the resistant bacteria in gut microbiota.

Increase in the Rate of Gut Carriage of Fluoroquinolone-Resistant Escherichia coli despite a Reduction in Antibiotic Prescriptions

Background : Fluoroquinolone use for urinary tract infections has been steadily declining. Gut microbiota is the main reservoir for uropathogenic Escherichia coli but whether the carriage of fluoroquinolone-resistant E. coli has been changing is unknown. Methods . We determined the frequency of isolation and other characteristics of E. coli nonsuceptible to fluoroquinolones (at ³0.5 mg/L of ciprofloxacin) in 515 and 1605 E. coli -positive fecal samples collected in 2015 and 2021, respectively, from non-antibiotic- taking women of age 50+ receiving care in the Seattle area Kaiser Permanente Washington healthcare system. Results . Between 2015 and 2021 the prescription of fluoroquinolones dropped nearly three-fold in the study population. During the same period, the rates of gut carriage of fluoroquinolone-resistant E. coli increased from 14.4 % to 19.9% (P=.005), driven by a significant increase of isolates from the recently emerged, pandemic multi-drug resistant clonal group ST1193 (1.7% to 4.3%; P=.007) and those with an incomplete set of or no fluoroquinolone-resistance determining mutations (2.3% to 7.5%; P<.001). While prevalence of the resistance-associated mobile genes among the isolates dropped from 64.1% to 32.6% (P<.001), co-resistance to third generation cephalosporins has increased 21.5% to 33.1%, P=.044). Conclusion . Despite reduction in fluoroquinolone prescriptions, gut carriage of fluoroquinolone-resistant uropathogenic E. coli increased with a rise of previously sporadic lineages and co-resistance to third generation cephalosporins. Thus, to reduce the rates of antibiotic resistant urinary tract infections, greater focus should be on controlling the gut carriage of resistant bacteria.

367. Procalcitonin as a Potential Biomarker in the Study of Human Babesiosis

Background

Procalcitonin (Pct) has been gaining momentum as a potential biomarker during parasitic infections as studies have demonstrated that Pct levels are significantly elevated during certain forms of protozoal sepsis. Given this, the goal of this pilot study is to determine the relationship between Pct levels and parasitemia (Par) during infection with Babesia microti and to elucidate the potential for Pct to be used as a biomarker in the study of babesiosis.

Methods

Babesia cases were collected from Stony Brook University Hospital (SBUH) and South Hampton Hospital (SHH) from 2012 to 2019. Median values of maximum Par and Pct throughout hospitalization were recorded and cases were referenced for admission to the intensive care unit (ICU).

Correlation between maximum Par and Pct values were examined with the nonparametric Spearman rank correlation and fractional polynomials were used to assess the functional form of the correlation. Receiver-operator characteristic (ROC) curve analyses were used to identify cutoff points for Pct and maximum Par as markers for prediction of ICU admission.

Results

A total of 33 patients met the inclusion criteria for acute babesiosis. In fractional polynomial analysis, log-transformed Pct levels had a linear correlation with log-transformed maximum Par, r=0.556 (P=0.001, Fig 1A). In ROC curve analysis, a cut off level of ≥ 1.2 ng/mL for Pct had optimal prediction characteristics for ICU admission (sensitivity 62.5%, specificity 88%; correct classification 82%) with a relevant AUC of 0.77 (95% CI: 0.58–0.89; P=0.005, Fig 1B). A cut off level of ≥ 3.6% for maximum Par had optimal prediction characteristics for ICU admission (sensitivity 75%, specificity 92%, correct classification 88%) with a relevant AUC of 0.75 (95% CI 0.58—0.89; P= 0.005, Fig 1B). Comparison of AUC for Pct and Par yielded no significant difference (P=0.8).

Figure 1A. Linear correlation between log10-parasitemia and log10- procalcitonin levels. The linear correlation of the log-transformed variables was r=0.556 (P=0.001), similar to the nonparametric (Spearman) correlation coefficient (ρ=0.567). The red dots represent patients who were admitted to the intensive care unit.

Figure 1B. Receiver-operator characteristic curve of parasitemia for prediction of intensive care unit admission (0.75; 95%CI: 0.58—0.89; P=0.005); optimal cut-off is 3.6%. Receiver-operator characteristic curve of procalcitonin for prediction of intensive care unit admission (C=0.77; 95%CI: 0.58–0.89; P=0.005); optimal cut-off is 1.2 ng/mL.

Conclusion

Our analysis demonstrated a positive linear correlation between Pct and maximum Par, which is the current standard marker for severe disease. Also, our ROC analyses estimate that Pct values ≥ 1.2 ng/mL and Par ≥ 3.6% suggests severe disease and need for ICU admission (Fig 1A, 1B). Given this, our findings suggest that Pct may have potential for predicting severe disease during babesiosis.

Disclosures

All Authors: No reported disclosures.

Interleukin-10 delivery via mesenchymal stem cells (MSC) to prevent ischemia/reperfusion injury in lung transplantation (141.46)

Ischemia-reperfusion injury (IR) is an important cause for lung graft loss (~30%). In this study, MSC & viral interleukin-10 (vIL-10) engineered MSC were tested for their ability to prevent lung IR injury. Bone marrow derived MSC from Lewis rat were transduced with rvIL-10-retrovirus & selected on neomycin. Following 120 min of left lung ischemia induction, Group A, rats received vIL-10-MSC (~15 x 106; i.v.); Group B, empty vector engineered MSC; Group C, MSC; Group D, saline; and Group E, no ischemia or MSC. Mean blood oxygenation (PaO2/FiO2 ratio, mmHg) was reduced (P&lt;0.05) at 24h post-IR injury in Group B (138±86; n=9) & Group D (87±39; n=10), compared to MSC-vIL10 (353±105; Group A; n=10) group. By days 3 & 7 with MSC-vIL10 oxygenation was normal (475±55 & 435±33; n&gt;9); by 4h it was 319±94 (n=7). MSC (passage ≤6) increased PaO2/FiO2 (454 ± 59; n=5) by 24h post-IR. Bronchoalveolar lavage at 24h post-MSC-vIL10 therapy reduced (P&lt;0.05) granulocytes, CD4 & CD8 T cells. Lung injury score (histopathology) was higher (P&lt;0.05) with no treatment (3.5 ± 1.3; n=5) compared to MSC-vIL10 (1.21± 0.6; n=7) & MSC (1.6±0.9; n=6) treated groups. Lung microvascular permeability & wet:dry ratio were lower (P&lt;0.05) in MSC-vIL10 group. IL-1α, MCP-1α, MIP-1α, & IL1-β were increased in IR injured lung. ISOL (in situ staining for DNA fragmentation) & CASPACE-3 demonstrated reduced (p&lt;0.05) number of apoptotic cells in MSC-vIL10 treated lungs. Ex vivo, expanded MSC were CD34-, CD31+ & CD45+ (5-10%), CD29+, CD90+ & CD44+ (65-95%), CD80 (0%), CD 86 (8%), MHC Class I+ (23-57%), & MHC Class II-. MSC & IL-10 delivery via MSC to prevent lung transplant IR injury seems promising.

Long-term complications of platinum-based chemotherapy in testicular cancer survivors

The purpose of this study was to describe the rates of cardiovascular and other medical complications related to the use of platinum-based chemotherapy in American testicular cancer survivors. The study sample consisted of 143 eligible long-term testicular cancer survivors. Participants were interviewed, their medical records were reviewed, and blood was obtained for cholesterol measurement during their follow-up visit. The mean follow-up time was 8.4 yr, and their mean age at follow-up was 41.2 yr; 72.7% had had non-seminoma, and 82.5% had received platinum-based chemotherapy. Hypertension rates in the platinum-treated group increased significantly from baseline to follow-up; however, once adjusted for blood pressure measurement (undiagnosed hypertension), no such increase was seen, and hypertension rates were already higher than national estimates at baseline in all groups. At the follow-up visit, the rates of hyperlipidemia (adjusted for measured cholesterol level) in both platinum- and non-platinum-treated groups (28.4% and 37.5%, respectively) were higher than national estimates (16.9%). Rates of coronary artery disease were higher in those who had received platinum and radiation (11.1%) than in those who had received platinum alone (4.3%), but this difference was not statistically significant. As suggested by previous studies, platinum-based chemotherapy may be associated with hypertension, hyperlipidemia, and coronary artery disease. However, our data suggest that undiagnosed hypertension and hyperlipidemia may be significant confounders, and we also observed a trend toward lower testosterone levels in participants who experienced cardiovascular complications.

Recipient Conditioning with Mesenchymal Stem Cells and Interleukin-10 Prolonged Cardiac Allograft Survival (102.1)

Mesenchymal Stem Cells (MSC) and viral interleukin-10 (vIL-10) have immunosuppressive properties. In this study, we tested their ability to prevent cardiac allograft rejection. Bone marrow derived MSC from Lewis rat were expanded ex vivo and transduced with rvIL-10-retrovirus. Autologous MSC or vIL-10 transduced MSC were injected (~25 x 106; i.v.) into irradiated (4 Gy) rat (RT1.Al). Six weeks later heterotopic heart (RT1.An) transplantation (Tx) was performed. MSC therapy prolonged (P&lt;0.05) cardiac allograft survival (14±1 days; n= 4) compared to untreated controls (7±1 days; n=4). Also, vIL-10-MSC treatment prolonged (P&lt;0.01) graft survival (38±1 days; n=6) compared to empty vector treated group (15±1 days; n=4). In vIL-10-MSC preconditioned animals that received donor bone marrow after heart Tx, graft survival was 22±2 days (n=8). Intragraft expression of co-stimulatory molecule (CD80) and cytokines (IL-2, IFN-γ) as determined by RT-PCR was lower (P&lt;0.03) in vIL-10-MSC treated grafts compared to untreated control grafts. Ex vivo expanded MSC were CD34−, CD45+(5 %), CD29+(90%), CD80 (0%), CD 86 (8%), CD90+(93%), MHC Class I+(23–57%), and MHC Class II- as determined by FACS. Both vIL-10 and empty vector engineered MSC expressed CD29 (&gt;95%) but not other molecules. The vIL-10-MSC produced ~ 6 ng/ml of vIL-10 ex vivo. vIL-10-MSC addition in MLR cultures inhibited lymphoproliferative response (P&lt;0.05). TGF-β expression in stimulated (TNF-α or IL1-β) and unstimulated MSC was 46 – 65% of β-actin. IL-2, IL-4, IL-10, IFN-γ, and TNF-α expression was negligible in MSC (0–7% of β-actin). VEGF and HGF mRNA expression in MSC was 58% and 5% of β-actin, respectively. TgGFP+ MSC were demonstrable in various tissues for &gt;28 days. Both MSC and vIL-10 conditioning to promote allograft survival seems promising.

Long-term complications of platinum in testicular cancer survivors

4589

Background: Long-term medical complications of platinum have become a major priority in the care of testicular cancer survivors. This study aimed to describe the prevalence of these complications from platinum-based therapy in American testicular cancer survivors. Methods: Testicular cancer survivors with no evidence of disease for at least 2 years were interviewed, had lab tests, and charts reviewed. Demographics, comorbidities, blood pressure, treatment, and outcomes were compared between all treatment modalities. NHANES 2002 and NHIS 2004 were used to obtain national estimates. Results: The mean age was 41 years; 72.7 % had nonseminoma, 96.5% had orchiectomy, 21.0% received radiation (XRT), and 82.5% platinum. The mean follow-up was 8.4 years. There was no statistical difference in the rates of Coronary Artery Disease (CAD), hyperlipidemia, hypertension (HTN), renal insufficiency (RI), or hypomagnesemia (see table ). There was a trend toward an increase in hyperlipidemia at follow-up compared to initial visit in all treatment groups but HTN increased only in those who did not receive platinum. Conclusion: Excluding HTN, we observed a trend toward an increase in the prevalence of RI, hypomagnesemia, hyperlipidemia, and CAD among patients who received platinum when compared to their baseline rates. Similar to a recent study by Huddart et al, we saw a trend toward higher risk of developing CAD in those who received both platinum and XRT. These findings suggest that hyperlipidemia and HTN may be more related to orchiectomy or the germ cell tumor itself than being a complication of platinum. Further prospective cohort studies with a larger group of survivors who have not received platinum are warranted to determine if HTN and hyperlipidemia are true complications of platinum-based chemotherapy.

[Table: see text]

No significant financial relationships to disclose.

Usefulness of catheter-directed thrombolysis using alteplase in peripheral vascular occlusion

This study evaluated the safety and efficacy of alteplase in catheter-directed treatment for peripheral arterial and venous thrombosis and considered the optimal dosing regimen. Forty-four patients (49 encounters) underwent transcatheter therapy using alteplase between January and November 1999. The most common indications for thrombolysis were peripheral arterial occlusion (PAO) and venous thrombosis (38 patients, 43 encounters). Each encounter was reviewed for indication, dosage of alteplase, duration of infusion, concomitant use of anticoagulation, degree of lysis, and complications. Patients were divided into low-dose (0.5 to 1.0 mg/hr), mid-dose (1.0 to 1.5 mg/hr), and high-dose (>1.5 mg/hr) groups. For PAO, there was no significant difference in the success rate between the 3 dose groups. A lower complication rate was achieved in the low-dose group. For venous thrombosis, there was no difference in the overall success or complication rates for each of the 3 groups. Partial lysis was achieved more readily in the mid and high-dose groups, but the risk of serious complications was greater. Overall, the complete thrombolysis rate was 71% for PAO and 55% for venous thrombosis. Major and minor complication rates were 7% and 19%, respectively. An equivalent success rate with a lower complication rate can be achieved using a low-dose constant catheter-directed infusion of alteplase for cases of PAO. Cases of venous thrombosis had a lower overall success rate compared with PAO. A mid-dose infusion of alteplase can achieve greater complete and partial thrombolysis rates without increasing the complication rate. Major and minor complication rates were similar to the rates given in the published literature.

Impact of HIV type 1 drug resistance mutations and phenotypic resistance profile on virologic response to salvage therapy

This study examines the association between presence of drug resistance mutations and phenotypic resistance at baseline to virologic response to salvage therapy in a community setting. The study population consisted of 58 antiretroviral drug-experienced patients with HIV-1 infection who had recently switched therapy because of virologic failure. Drug resistance mutations in the reverse transcriptase- and protease-coding regions and phenotypic susceptibility to 13 antiretroviral drugs were assessed at baseline. Plasma HIV-1 RNA levels were assessed at baseline and at subsequent clinic visits. Results showed that three variables were significant in predicting virologic response: HIV-1 levels at baseline, number of protease mutations, and phenotypic sensitivity score for the regimen at baseline. For four drugs there was a significant association between the presence of specific drug resistance mutations and >10-fold phenotypic resistance to that drug. With phenotypic resistance defined as >4-fold resistance, the association between specific drug resistance mutations and phenotypic resistance was significant for seven drugs. Overall, these data show that phenotypic susceptibility and absence of drug resistance mutations, particularly protease mutations, are significant predictors of virologic response. For several drugs, specific combinations of drug resistance mutations are associated with decreased phenotypic susceptibility and might provide useful clinical guidelines in selecting therapeutic options.

Pyruvate inhibits hepatic ischemia-reperfusion injury in rats

BACKGROUND

Ischemia/reperfusion (I/R) injury is a limiting factor in liver transplantation. We have recently shown that pyruvate (PY) inhibits intestinal and renal I/R injury. This study aims to evaluate the protective effect of PY on hepatic I/R injury.

METHODS

ACI rats were treated with PY, whereas control animals received placebo. Rats were killed after 60 min of partial hepatic ischemia and after 2, 6, 24, and 48 hr of reperfusion. For each time point, serum aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase were measured, and liver biopsy specimens were obtained to evaluate morphology, DNA fragmentation, and apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling).

RESULTS

The survival rate 48 hr after I/R was 83% in the control group, and 100% in the PY-treated group (P>0.05). Increased enzymatic levels and histologic findings showed increased liver damage in the untreated group compared with PY. In control rats, apoptosis was enhanced after 1 hr of ischemia and peaked after 2 hr of reperfusion, to decrease gradually 48 hr after reperfusion; in the PY group apoptosis was delayed and reduced. After 1 hr of ischemia, the number of apoptotic nuclei was significantly increased in control livers compared with normal preischemic livers, whereas the number was significantly reduced by PY. After 2 hr of reperfusion, the maximum number of apoptotic cells was observed, whereas PY significantly reduced the amount of apoptotic cells (P<0.05). Apoptosis was delayed in PY-treated livers to 6 hr after reperfusion, peaking at a significantly lower count compared with placebo-treated controls (P<0.05).

CONCLUSION

These data indicate that PY has a protective effect on I/R injury of the liver.

[Validation of a scale for responsibility (Salkovskis Responsibility Scale)]

Appraisal of inflated responsibility for harm is the cornerstone of Salkovskis's cognitive theory for obsessive compulsive disorder. The aim of our study is to present the validation study of the French translation of the R scale. The present study compared 50 subjects with obsessive compulsive disorder, 37 patients suffering from social phobia and 183 control subjects on a responsibility questionnaire (R scale). The cognitive hypothesis of Obsessive Compulsive Disorder (OCD) specifies two levels of responsibility-related cognitions: responsibility assumptions (attitudes) and responsibility appraisals (interpretations). The R scale evaluates the responsibility assumptions. Such attitudes should reflect the more generalized tendency to assume responsibility in a given situation, particularly situations involving intrusions and doubts. It is possible that such assumptions may be less specific to OCD. The inclusion of social phobia subjects in the present study allows evaluation of the specificity of any findings to OCD. Patients were diagnosed and classified according DSM IV criteria. The control subjects were taken in the general population. No formal interview was conducted. The three groups were compared for sex, age and educational level. Before treatment, all the participants filled in the Responsibility Scale of Salkovskis (27 items), the Beck Depression Inventory (21 items), the Beck Anxiety Inventory and the Bouvard's Obsessive Compulsive Thoughts Checklist. The results indicate that the two anxious groups scored significantly higher than the control group on Beck Depression and Anxiety Inventories but no significant difference was observed between the two anxious groups. OCD patients scored significantly higher than both social phobic patients and control subjects on the Obsessive Compulsive Thoughts Checklist (OCTC). The social phobic group scored this checklist significantly higher than the control group. In sum, the three groups were different on obsessive compulsive thoughts. On the washing subscale of the Obsessive Compulsive Thoughts Checklist, the OCD patients differed significantly from the control group and the social phobia patients. No difference was observed between the social phobia subjects and the control group. On the two other subscales of the OCTC, the checking and the responsibility scales, the three groups were different: OCD patients scored significantly higher than both social phobic patients and control subjects; the social phobic patients scored higher than the control group. Results support the reliability (test retest) and the internal consistency of the questionnaire. Patients with obsessive compulsive disorder (OCD) and social phobia subjects had significantly elevated score on the total scale compared to control subjects. However social phobia patients did not differ from patients with OCD. So, the responsibility for harm, evaluated by the R-scale seems not to be specific of OCD. This finding does not support the results of two studies (28, 30). But these two studies compared OCD patients with an anxious group including panic disorder with agoraphobia, generalized anxiety disorder and social phobia. The correlations with a measure of OCD symptoms were higher than the correlations with anxiety and depression. Finally, the factor structure was only studied on the control group. The exploratory factor analysis indicates that the R scale is a two-dimensional scale, reflecting a need to prevent risks and the belief that one has power to harm. The first dimension is less specific to the pathology than the second. Only patients with OCD had significantly elevated score on the "need to prevent risks" compared to the non-clinical group. The two anxious groups differed on "the belief that one has power to harm" from the non-clinical group but social phobia patients did not differ from patients with OCD. In sum, the two subscales of the R scale did not discriminate OCD patients and social phobic subjects. Further research is needed to replicate the present findings and to confirm the two dimensions of the R scale. Overall, the results are consistent with the hypothesis that responsibility beliefs are important in the experience of obsessional problems. However, responsibility assumptions such as the belief that one has the power to harm are shared with social phobia.

[Etiology of asthma]

Asthma is a chronic inflammatory disease of the airways which occurs in genetically predisposed individuals. This common disease has an epidemic progression in western countries. Despite the identification of several candidate genes, genetic modifications cannot explain the recent increase in asthma prevalence and severity in the last forty years. Environmental factors are likely to be the cause of the progression of this epidemic inflammatory disease.

Note: dissolution of aerosol particles of budesonide in Survanta, a model lung surfactant

The effect of a pulmonary surfactant extract from bovine lung, Survanta, on the dissolution rate of aerosol particles of budesonide was determined. Aerosol particles of budesonide were generated from an ethanol solution, dried, and collected by a cascade impactor for characterization or by a liquid impinger for dissolution experiments. Powder x-ray diffraction, differential scanning calorimetry, differential thermal analysis, and scanning electron microscopy were used to characterize the aerosol particles and starting material. No change in phase was detected, although the aerosol particles appeared to contain residual solvent. The dissolution rate of the aerosol particles in saline was low and variable. Survanta increased the extent of dissolution of budesonide in proportion to the added concentration, which was also verified by equilibrium solubilization studies. Survanta also increased rate of dissolution, in a manner similar to sodium dodecyl sulfate. Analysis of the concentration of budesonide following ultracentrifugation indicated that there is rapid equilibration of budesonide between the Survanta and aqueous phase. These results show that lung surfactant has the potential of enhancing the rate and extent of dissolution of drugs administered to the lung.

Inhaled corticosteroids and Churg-Strauss syndrome: a report of five cases

Churg-Strauss syndrome is an eosinophil-associated, small vessel granulomatous vasculitis, characterized by late onset asthma, upper airways disease, eosinophilia, and clinical manifestations of systemic vasculitis. Several cases of Churg-Strauss syndrome have been recognized in patients treated with cysteinyl leukotriene-receptor antagonists and weaned off systemic corticosteroids. These cases have led to a general warning on the possible development of Churg-Strauss syndrome after taking cysteinyl leukotriene-receptor antagonists. The authors report five cases of Churg-Strauss syndrome in severe steroid dependent asthmatics in whom inhaled corticosteroids allowed systemic corticosteroid withdrawal. It is concluded that physicians should monitor patients carefully when severe asthma is controlled with any substance allowing withdrawal from (or even avoidance) of systemic corticosteroids. Case-control studies should identify more precisely the risk factors of Churg-Strauss syndrome.

Hydraulic high-pressure nebulization of solutions and dispersions for respiratory drug delivery

The purpose of this investigation was to assess hydraulic high-pressure nebulization as a means for respiratory drug delivery. A hydraulic high-pressure nebulizer was designed and constructed. In a design study, the output efficiency and the aerosol particle size were determined for the nebulizer as a function of nozzle diameter (5, 10, and 20 microns), gas flow rate (2 and 8 l/min), applied hydraulic pressure (2200 and 4000 psig), and distance between the nozzle orifice and impaction surface (0.25-4 cm) with an aqueous solution of fluorescein. The output efficiency was also measured with an ethanol solution and an aqueous phospholipid dispersion of liposomes. For the design study, each factor had an effect. The efficiency tended to increase with a decrease in the nozzle diameter, although the differences between the 5- and 10-micron nozzle were more sensitive to the air flow rate and nozzle-to-impaction-surface distance. Greater efficiencies were always obtained at the higher ancillary air flow rates. Operating the nebulizer at different pressures caused a change in the functional relationship between the efficiency and the nozzle-to-impaction-surface distance. For the 5-micron nozzle at high pressure, efficiency fell with increasing nozzle-to-impaction-surface distance, whereas for the data obtained with the 20-micron nozzle, the efficiency increased with nozzle-to-impaction-surface distance, with lower efficiencies obtained at the higher pressures. For the remaining observations made with the 5- and 10-micron nozzles, the efficiency as a function of nozzle-to-impaction-surface distance appeared to be variable. For the 5- and 10-micron size nozzle, there was no significant effect of the air flow rate, pressure, or nozzle-to-impaction-surface distance on the mass median aerodynamic diameter and geometric standard deviation. For the 20-micron size nozzle, the particles were not completely dried. Ethanol solutions gave somewhat higher efficiencies, whereas the phospholipid dispersion gave efficiencies comparable to the aqueous solutions nebulized under similar conditions. The efficiency of the hydraulic high-pressure nebulizer appears to be correlated with the calculated properties of the liquid jet. For respiratory drug delivery, the hydraulic high-pressure nebulizer provides reasonably high outputs of respirable particles independent of time from a single pass of liquid through the nebulizer.

Analysis of a diffusion dryer for the respiratory delivery of poorly water soluble drugs

PURPOSE

The purpose of this study was to analyze a diffusion dryer as a means to remove organic solvents from aerosol particles of poorly water soluble drugs.

METHODS

Aerosols of methanol, ethanol, and ethyl acetate were generated with an ultrasonic nebulizer, and inflow to outflow concentration ratio of vapor in a annular charcoal column was determined as a function of time by gas chromotography at two to four different airflow rates. In addition, the particle transmission efficiency was determined with an ethanol solution of the test compound, budesonide. The results were analyzed with equations originally developed for assessing the loss of drug from intravenous tubing along with independent measures of the adsorption isotherm of the vapors onto charcoal.

RESULTS

Aerosol production was relatively constant with time, and the transmission of solid particles through the column occurred with efficiency nearing 100%. The inlet to outlet vapor concentration ratio was adequately described by a model of three resistances in series composed of the inner tube, the screen mesh, and the charcoal bed.

CONCLUSIONS

The diffusion dryer was found to be satisfactory for the removal of methanol, ethanol, and ethyl acetate and the efficiency may be assessed from the adsorption isotherms on charcoal and the geometry of the dryer.

Infusion of donor leukocytes to induce tolerance in organ allograft recipients

To further enhance chimerism, 229 primary allograft recipients have received perioperative intravenous infusion of a single dose of 3 to 6 X 10(8) unmodified donor bone marrow (BM) cells/kg body weight. In addition, 42 patients have been accrued in a concurrent protocol involving multiple (up to three) sequential perioperative infusions of 2 x 10(8) BM cells/kg/day from day 0-2 posttransplantation (PTx). Organ recipients (n = 133) for whom BM was not available were monitored as controls. The infusion of BM was safe and except for 50 (18%), all study patients have optimal graft function. Of the control patients, allografts in 30 (23%) have been lost during the course of follow-up. The cumulative risk of acute cellular rejection (ACR) was statistically lower in the study patients compared with that of controls. It is interesting that, 62% of BM-augmented heart recipients were free of ACR (Grade > or = 3A) in the first 6 months PTx compared to controls. The incidence of obliterative bronchiolitis was also statistically lower in study lung recipients (3.8%) compared with the contemporaneously acquired controls (31%). The levels of donor cell chimerism were at least a log higher in the peripheral blood of majority of the study patients compared with that of controls. The incidence of donor-specific hyporeactivity, as determined by one-way mixed leukocyte reaction, was also higher in those BM-augmented liver, kidney, and lung recipients that could be evaluated compared to controls.

Synthesis and kinetics of cyclization of MHC class II-derived cyclic peptide vaccine for diabetes

Conformationally constrained cyclic peptides are known to be better vaccines because of their ability to mimic the native structure of a protein against which an immune response is sought. To test the hypothesis of using conformationally constrained, disease-associated, MHC-derived peptides as vaccines for the prevention of type I diabetes, a 22 amino acid nonobese diabetic(NOD) mouse MHC class II-derived synthetic peptide was cyclized by the formation of end-to-end disulfide bonds and used to prevent diabetes and insulitis in NOD mice. The peptide was synthesized by Fmoc chemistry and cyclized using two methods: a commercially available cyclizing resin (Ekathiox) and air oxidation. When a 10 m excess of resin was used, the Ekathiox yielded a substantial amount of cyclic peptide with few or no side reactions. The kinetics of cyclization by air oxidation at different temperatures indicated that increasing both temperature and pH decreased the cyclization time significantly. Air oxidation at pH 10 at 37-55 degrees C yielded the desired product within 2 h.