Reconsidering Luria's speech mediation: Verbalization and haptic picture identification in children with congenital total blindness

Current accounts of behavioral and neurocognitive correlates of plasticity in blindness are just beginning to incorporate the role of speech and verbal production. We assessed Vygotsky/Luria's speech mediation hypothesis, according to which speech activity can become a mediating tool for perception of complex stimuli, specifically, for encoding tactual/haptic spatial patterns which convey pictorial information (haptic pictures). We compared verbalization in congenitally totally blind (CTB) and age-matched sighted but visually impaired (VI) children during a haptic picture naming task which included two repeated, test-retest, identifications. The children were instructed to explore 10 haptic schematic pictures of objects (e.g., cup) and body parts (e.g., face) and provide (without experimenter's feedback) their typical name. Children's explorations and verbalizations were videorecorded and transcribed into audio segments. Using the Computerized Analysis of Language (CLAN) program, we extracted several measurements from the observed verbalizations, including number of utterances and words, utterance/word duration, and exploration time. Using the Word2Vec natural language processing technique we operationalized semantic content from the relative distances between the names provided. Furthermore, we conducted an observational content analysis in which three judges categorized verbalizations according to a rating scale assessing verbalization content. Results consistently indicated across all measures that the CTB children were faster and semantically more precise than their VI counterparts in the first identification test, however, the VI children reached the same level of precision and speed as the CTB children at retest. Overall, the task was harder for the VI group. Consistent with current neuroscience literature, the prominent role of speech in CTB and VI children's data suggests that an underlying cross-modal involvement of integrated brain networks, notably associated with Broca's network, likely also influenced by Braille, could play a key role in compensatory plasticity via the mediational mechanism postulated by Luria.

The effect of sourdough, turnips, and butternut squash on the physicochemical and nutritional properties of Doowina functional food during fermentation

The dairy-cereal-based food, known as Doowina, is one of the traditional fermented foods in Iran. We aimed to improve the health-promoting properties of Doowina by using turnips, butternut squash, and sourdough as a new functional food with high nutritional value and antioxidant activity. Therefore, the physicochemical, microbial, and sensory properties of samples with nutritional supplements (8% turnip and 8% butternut squash) and different concentrations of sourdough (0, 0.5, and 1%) were studied during 0, 3, 6, and 9 days of fermentation time. The results showed that there was no significant difference (p < .05) in the moisture and ash content between the different formulations of Doowina. There was also no significant difference (p < .05) in the phenolic compound content and antioxidant activity of the Doowina samples during the fermentation period. However, the number of lactic acid bacteria (LAB) increased significantly (p < .05) until the 6th day of fermentation, and the protein content decreased significantly (p < .05) in all samples during the fermentation period. According to the results, the samples with butternut squash and sourdough had the highest total phenolic content, the highest antioxidant activity, the highest linoleic acid content, and the highest sensory rating of all samples.

Multi-Institutional Phase II Trial Using Dose Escalated Five Fraction Stereotactic Partial Breast Irradiation (S-PBI) with GammaPodTM for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

We report on our early experience of a multi-institutional phase II study of dose escalated five fraction stereotactic partial breast irradiation (S-PBI) for early-stage breast cancer after partial mastectomy using the GammaPodTM stereotactic radiation system.

MATERIALS/METHODS

Patient eligibility included DCIS or invasive epithelial histologies, AJCC clinical stage 0, I, or II with tumor size < 3 cm, and negative margins. Prior safety of Phase I dose escalation has been reported. Dose was 40 Gy delivered in 5 fractions to the CTV, and minimum dose 30 Gy in 5 fractions to the PTV. CTV margin was 1 cm and PTV margin 3 mm. For PTV cavities larger than 100cc, dose was reduced to 35Gy in 5 fractions to the CTV and 30 Gy in 5 fractions to the PTV. Primary endpoint of the study is to determine the 3-year patient global cosmesis score (4-point scale excellent, good, fair, or poor) and adverse cosmesis using a dose escalated approach with smaller PTV margins than conventional methods. Both patients and physicians completed baseline and subsequent cosmesis outcome questionnaires. Treatment related toxicity was graded using the NCI version 4.0 and RTOG/EORTC late radiation scale.

RESULTS

From 3/2019-10/2021, 74 patients were treated respectively. Of these, 38 were treated to 40Gy and 36 were treated to 35 Gy. Median follow up (f/u) was 24 months (mo), range (r) 3-39mo. Median age was 63 years (r 43-77). Histology included 28 DCIS, and 46 invasive carcinomas. 45/46 invasive tumors were ER+. 60/74 (81%) patients received endocrine therapy, and 7/74 patient received chemotherapy. There were 221 acute grade 1 toxicities, and 28 Grade 2 toxicities. No grade 3 or higher acute toxicities were reported (< 90 days). The most common Grade 2 toxicities were radiation dermatitis (10), breast pain (8), blister (4), skin infection (2), nipple discharge (2), and fatigue (2). In the late period, there were 54 Grade 1 late toxicities, 4 Grade 2 late toxicities, and no Grade 3 or higher late toxicities. Grade 2 toxicities included fibrosis (2), and pain (2). Two patients developed grade 1 asymptomatic nonpalpable fat necrosis both diagnosed at 12 months after radiation treatments. The most common grade 1 late toxicities were breast pain (14), hyperpigmentation (8), fibrosis (10), and fatigue (5). Physicians scored cosmesis excellent or good 70/73 (95.8%), 58/60 (96.7%), 36/36 (100%),17/17(100%) respectively at baseline, 12 months, 24 months, and 36months post SBRT, while patients scored the same periods 62/71 (83.7%), 53/59 (89.8%), 33/36 (91.6%), 17/18 (94.4%). There have been no reports of disease recurrences.

CONCLUSION

Results at 24-month median follow-up, of our dose escalated stereotactic partial breast 5 fraction regimen, has low acute and late toxicity, while maintaining high proportion of excellent/good cosmetic outcomes. Continued analysis of all cohorts is in progress.

CLINICAL TRIALS

gov identifier is NCT03581136.

Financial Toxicity and Patient Experience Outcomes on a Multi-Institutional Phase I Single Fraction Stereotactic Partial Breast Irradiation Protocol for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

Given the demonstrated financial toxicity (FT) of radiation treatment on breast cancer patients shown in both conventional and our recent 5 fraction stereotactic APBI (S-PBI) study, we assessed the FT, as well as patient-reported utility, quality-of-life and patient experience measures, on patients treated in our phase I single fraction S-PBI trial.

MATERIALS/METHODS

A phase I single fraction dose escalation trial of S-PBI for early-stage breast cancer was conducted. Women with in-situ or stage I-II (AJCC 6) invasive breast cancer following breast conserving surgery were treated with S-PBI in 1 fraction to a total dose of 22.5, 26.5 or 30 Gy (Clinical trials.gov ID NCT02685332). At one month follow-up, patients were asked to complete our novel "Patient Perspective Cost and Convenience of Care Questionnaire". Patients also completed the EQ-5D-5L, including the visual analogue scale of overall health (VAS), at enrollment, 6, 12-, 24-, 36-, and 48-month follow-up.

RESULTS

Of 29 patients enrolled and treated, questionnaire data was available for all patients. Our trial encompassed a wide range of annual household incomes, education, and employment status. Overall, 44.8% (n = 13/29) of patients reported that radiation treatment presented a financial burden. Interestingly, no demographic information, such as patient race, marital status, education, household income, or employment during treatment predicted perceived FT. Patients reporting FT trended towards younger age (median 64 vs 70.5) and having a cancer related co-pay similar to our 5 fraction S-PBI FT trial; however, due to the small size of this study, this did not reach significance (p = 0.24 and 0.10, respectively). VAS and utility scores were calculated per the EQ-5D-5L and remained unchanged from baseline through 4-year follow-up. Likewise, there was no difference in the utility or VAS between patients who reported FT and those who did not. Interestingly, while patient reported cosmesis was similar for all patients at enrollment, patients who reported FT noted significantly worse cosmesis scores (fair/poor vs good/excellent) at 6 month and 2-year follow-ups (p = 0.01 and 0.04, respectively). Finally, patients were surveyed on treatment related disruption to their daily activities and enjoyment of life. The median values were 0 (scale 0-10, with 0 being no disruption) regardless of perceived FT. Patients were also uniformly satisfied with treatment time with a median score of 10 (scale 0-10, 10 being most satisfied).

CONCLUSION

Here, we show that despite using SPBI in a single fraction, nearly half of the patients treated still reported FT of treatment. Importantly, single fraction S-PBI has no negative impact on patient VAS or utility scores, and all patients were uniformly satisfied with treatment time without significant disruption to their life.

A Preliminary Study on the Antigenic Proteins of Linguatula serrata Nymphal Stage in Sheep with Visceral Linguatulosis

Scant information is available on the immunological aspect of Linguatula serrata causing linguatulosis in humans and animals. The present study aimed to analyze the content of crude somatic extracts and excretory-secretory products of L. serrata nymphs to detect the immune response of sheep and immunogenic proteins of the parasite. After collecting the nymphs, somatic extracts were prepared by sonication. Excretory secretory products were prepared by the incubation of nymphs in RPMI medium at 37°C with 5% CO2. Somatic and excretory-secretory proteins were isolated using SDS-PAGE. The immunogenic properties of the resulting proteins were determined using immunoblotting and positive sera from sheep infected with visceral linguatulosis. The total content of somatic extracts and excretory-secretory products of L. serrata nymphs analyzed by SDS-PAGE (12% gel) revealed two protein patterns with more than 18 and 9 strong bands, respectively. Immunoblots using sera samples of sheep infected with the parasite, somatic extracts and excretory-secretory products demonstrated 12 and 3 antigenic proteins with molecular weights mostly in the range of 24-100 kDa and an antigen more than 180 kDa. Three common immunodominant antigenic proteins with molecular weights of 38 and 57, as well as an antigen of more than 180 kDa, were detected in the somatic extracts and excretory-secretory products of L. serrata nymphs in sheep with visceral linguatulosis. These antigens can be considetered prime candidates for future serodiagnosis and immunoprotective studies of the parasite.

POS0349 SEQUENCE COMPLEMENTARITY BETWEEN SARS-CoV-2 GENOME AND HUMAN NONCODING RNAS ASSOCIATED WITH IMMUNOLOGICAL DISORDERS: AN IN SILICO PIVOTAL STUDY

Background:

Recent evidence shows that human cells may produce several noncoding (nc)RNAs in response to viral infections. Among them, a central role has been attributed to long noncoding (lnc)RNAs, more than 200 nucleotides in length, which are also crucially involved in cancer and autoimmunity. LncRNAs epigenetically control the transcription of genes presiding over cell proliferation, differentiation, migration and apoptosis, by directly or indirectly binding cellular or foreign nucleic acids, including viral genomes.

Objectives:

The objectives of this study were to evaluate in silico the presence of a nucleotide sequence complementarity between the RNA genome of Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2) and human ncRNA genes and to analyze any associations between SARS-CoV-2 gene-matching ncRNAs and human diseases.

Methods:

The FASTA sequence of each of the 11 SARS-CoV-2 isolate Wuhan-Hu-1 genes (ORF1ab, ORF3a, ORF6, ORF7a, ORF7b, ORF8, ORF10, S, E, M, N) was retrieved from NCBI.nlm.nih.gov/gene (reference sequence NC_045512.2). The ensembl.org library for human ncRNA genes was interrogated for any base-pair match and detected human ncRNAs analyzed for their functional activity. Finally, the associations between ncRNAs and human diseases were searched on GWAS databases (https://www.ebi.ac.uk/gwas and https://www.genecards.org).

Results:

A total of 252 matches between SARS-CoV-2 genes and human ncRNAs were recorded (ORF1ab: 28; ORF3a: 9; ORF6: 50; ORF7a: 31; ORF7b: 16; ORF8: 23; ORF10: 5; S: 24; E: 17; M: 32; N: 17). With the exception of two small nuclear RNAs (RNVU1-4 and RNU4-74P corresponding to ORF6 and ORF10, respectively), all of them were lncRNAs, mostly expressed in testis and central nervous system under physiological conditions. Percentage of alignment ranged from 91.30% to 100%, with a mean nucleotide alignment length of 17.5±2.4. Polymorphic variants of these transcripts have mostly been reported in patients with neuropsychiatric disorders, cancer and dysmetabolism. Of note, we found 13 and 15 complementarities with lncRNAs associated with immune-mediated diseases Table 1. and immunological pathways (IL-2, IL-6, IL-12, IL-12R, IL-13, IL-17, M-CSF, CXCL-10, TRAIL-R2 and IgG glycosylation), respectively.

Conclusion:

This pivotal study shows that SARS-CoV-2 genes contain complementary sequences to human ncRNAs in turn associated with several diseases, including autoimmunity. The biological effects of this interaction remain to be elucidated.

Table 1.

SARS-CoV-2 complementary ncRNAs and associated immunological disorders

SARS-CoV-2 geneLncRNAGenomic locationNucleotide alignment lengthAlignment percentageAssociated immunological disorderSXACTX:113705866-11370588318100%Crohn’s diseaseNLINC013581:59082428-5908257417100%Acute Graft-versus-Host DiseaseECOX10-AS117:14029229-1402924517100%Systemic lupus erythematosusORF8AC093765.34:116752764-1167527842195.24%Ulcerative colitisORF6CDKN2B-AS19:22033529-2203354618100%Multiple sclerosisCHROMR2:178433948-1784339682195.24%Multiple sclerosisPsoriasisAtopic eczemaWAKMAR26:137857643-13785765715100%Atopic eczemaHay feverAllergic rhinitisMultiple sclerosisPsoriasisSystemic sclerosisSystemic lupus erythematosusRheumatoid arthritisAC008691.15:159362809-159362828(promoter flank)2095%SarcoidosisPsoriasisPsoriatic arthritisSclerosing cholangitisCeliac diseaseType I diabetes mellitusSystemic lupus erythematosusJuvenile idiopathic arthritisUlcerative colitisCrohn’s diseaseTakayasu arteritisMultiple sclerosisLMCD1-AS13:7953602-7953616(enhancer)15100%Systemic sclerosisMLINC019342:181403969-18140398416100%Multiple sclerosisAnkylosing spondylitisCeliac diseaseRheumatoid arthritisORF7bXACTX:113959816-11395983116100%Crohn’s diseaseLINC0262110:62289643-6230233515100%Rheumatoid arthritisLINC019913:187966255-18796626915100%IgA deficitAtopic asthmaAllergic rhinitis

Disclosure of Interests:

None declared

Efficacy of amiodarone and voriconazole combination therapy in cutaneous leishmaniasis in the mice experimentally infected with Leishmania major

INTRODUCTION

The aim of the present study was to evaluate in vitro and in vivo efficacy of combination therapy of amiodarone and voriconazole against Leishmania major and investigating immune and wound healing responses of cutaneous leishmaniasis to this combination therapy.

METHODS

For in vitro study, replication of L. major promastigotes and intracellular amastigotes were investigated in the presence and absence of amiodarone and voriconazole. Isobologram construction and calculation of the Fractional Inhibitory Concentration (FIC) were performed. After the appearance of ulcers on the base of tails of BALB/c mice, treatment was initiated by a combination of amiodarone at 40 mg/kg plus voriconazole at 30 mg/kg orally and glucantime at 60 mg/kg intraperitoneally for 28 consecutive days.

RESULTS

According to the concave isobologram and fractional inhibitory concentration <1, combination of amiodarone plus voriconazole had synergistic effects against L. major promastigotes and intracellular amastigotes. There were less inflammatory cells, more fibroblasts and more collagen deposition in tissue sections in the mice treated with combined drugs compared to the vehicle and untreated mice. Increased glutathione peroxidase activity and decreased malondialdehyde, Interleukin-6, and Tumor necrosis factor-α levels were detected in the combination therapy group in comparison to the vehicle and untreated groups.

CONCLUSIONS

It seems a combination of amiodarone plus voriconazole can be a rational and promising therapeutic approach in the treatment of cutaneous leishmaniasis.

Effectiveness of amiodarone in treatment of cutaneous leishmaniasis caused by Leishmania major

Development of new chemotherapeutic agents is an essential issue in the treatment and control of a disease. This study aimed to evaluate the anti-leishmanial activity of amiodarone, an antiarrhythmic class III drug, against Leishmania major, the most prevalent etiological agent of cutaneous leishmaniasis in the old world. The proliferation of promastigotes and intracellular amastigotes in the absence or presence of amiodarone was estimated, in an in vitro study. For in vivo study, five weeks after infection of BALB/c mice with L. major, when the lesions appeared at the injection site, the mice were divided into four groups (n = 6 each); treatment was conducted for 28 consecutive days with vehicle, amiodarone at 40 mg/kg orally and glucantime at 60 mg/kg intraperitoneally. Therapy with amiodarone reduced the size of lesions compared to the untreated group after 12 days. Amiodarone decreased the parasite load and inflammatory responses, particularly the macrophages containing amastigotes, and enhanced granulation tissue formation in the dermis and subcutaneous area. The Tumor necrosis factor-α and Interleukin-6 levels were significantly lower in the cell culture supernatants of the inguinal lymph node in the amiodarone treated group compared to the vehicle and untreated groups. Amiodarone significantly increased the activity of glutathione peroxidase in comparison to the vehicle and untreated groups but did not affect the plasma levels of superoxide dismutase, malondialdehyde, adiponectin, and ferric reducing ability of plasma. Therefore, the anti- L. major activity and immunomodulatory effects of amiodarone reduced the parasitic load and enhanced wound healing in cutaneous leishmaniasis in BALB/c mice. Amiodarone reduced the lesion surface area, but it did not cure it completely.

Emerging role of amiodarone and dronedarone, as antiarrhythmic drugs, in treatment of leishmaniasis

Leishmaniasis is a group of human and animal diseases causing 20,000-40,000 annual deaths and its etiological agents belong to the Leishmania genus. The most current treatment against leishmaniasis is chemotherapy. Pentavalent antimonials such as glucantime and pentostam have been administrated as the first-line drugs in treatment of various forms of leishmaniasis. The second-line drugs such as amphotericin B, liposomal amphotericin B, miltefosine, pentamidine, azole drugs and paromomycin are used in resistant cases to pentavalent antimonials. Because of drawbacks of the first-line and second-line drugs including adverse side effects on different organs, increasing resistance, high cost, need to hospitalization and long-term treatment, it is necessary to find an alternative drug for leishmaniasis treatment. Several investigations have reported the effectiveness of amiodarone, the most commonly used antiarrhythmic drug, against fungi, Trypanosomes and Leishmania spp. in vitro, in vivo and clinical conditions. Moreover, the beneficial effects of dronedarone, amiodarone analogues, against Trypanosoma cruzi and Leishmania mexicana have recently been demonstrated and such treatment regimens resulted in lower side effects. The anti- leishmanial and anti- trypanosomal effectiveness of amiodarone and dronedarone has been attributed to destabilization of intracellular Ca²⁺ homeostasis, inhibition of sterol biosynthesis and collapse of mitochondrial membrane potential. Because of relative low cost, excellent pharmacokinetic properties, easy accessibility and beneficial effects of amiodarone and dronedarone on leishmaniasis, they are proper candidates to replace the current drugs used in leishmaniasis treatment.

A Serological Survey of Neospora caninum Infection in Urban and Rural Dogs in Ahvaz District, Southwest of Iran

Dogs are important in the epidemiology of Neospora caninum because they act as definitive hosts, shedding oocysts in the environment. The aim of the present survey was to evaluate the serological prevalence of Neospora caninum infection in urban and rural dogs in Ahvaz district, southwest of Iran. In this study, blood samples were taken from 100 rural dogs and 50 urban dogs. The dogs were categorized into two age groups (i.e., &amp;le; 3 and &amp;gt; 3 years). Neospora agglutination test (NAT) was performed for the detection of infection. Among 150 samples, 30 (20%) showed infection in 1:50 to 1:800 dilutions by NAT (confidence interval 95%: 13.60-26.40). The antibody titers were as follows: 1:50 (n=1), 1:100 (n=14), 1:200 (n=3), 1:400 (n=10) and 1:800 (n=2). The highest serum dilution was 1:100 in 46.67% of the infected dogs and the lowest serum dilution was 1:50 in 3.33% of them. The obtained results showed a significant difference in seroprevalence between urban (10%) and rural (25%) dogs (P=0.03). Although the seroprevalence was higher in dogs above three years of age (23.33%) than below three years (17.78%), there was not a significant difference among different age groups in this regard (P&amp;gt;0.05). The possibility of infection in dogs above the age of three years was 1.3 more than those below three years of age (confidence interval 95%: 0.58-2.9). It can be concluded that a relatively considerable percentage of dogs in Ahvaz district are infected with N. caninum. These infected dogs can play an important role in the transmission of neosporosis to other animals.

Evaluation of Local tissue oxidative stress and its possible involvement in the pathogenesis of toxoplasmosis in rats experimentally infected with Toxoplasma gondii

Toxoplasmosis caused by the protozoan parasite Toxoplasma gondii, is a zoonotic parasitic disease. Oxidative stress plays a dominant role in the host's defense against protozoan infection. In the present study the possible involvement of local oxidative stress in the pathogenesis of T. gondii were investigated. Twenty five female Wistar rats were infected with RH strain of Toxoplasma tachyzoites and twenty female rats were used as control group that only received sterile PBS. Tissue samples from liver, heart and brain on 0, 3, 5, 8 and 45 days post infection were collected. As biochemical markers of oxidative stress, endogenous concentrations of GSH, GPX and SOD activity, MDA level, protein carbonyl content and total antioxidant capacity were determined from the mentioned tissues of control and infected rats. Based on the results, on day 3, 5 and 8 post infection the level of hepatic glutathione were significantly decreased in infected rats when compared to control. There was a significant rise in hepatic glutathione peroxidase activity and malondialdehyde level on the third day post infection in comparison to uninfected rats. Significant elevation of superoxide dismutase activity and malondialdehyde level on 5 day post infection and protein carbonyls and total antioxidant capacity on 8 day post infection in infected livers were obtained. Significant changes of glutathione level, total antioxidant capacity and protein carbonyls contents were observed in cardiac homogenate on days 3, 5 and 45, respectively. Measured parameters were constant throughout all stages of experiment in brain of infected rats. Indeed increased production of reactive oxygen species accompanies Toxoplasma infection in liver and heart tissues of experimentally infected rats. Based on this study, antioxidant defense system can probably play a role in parasitic stage interconversion and shifting the toxoplasmosis into the chronic phase.

Smart micro/nanoparticles in stimulus-responsive drug/gene delivery systems

New achievements in the realm of nanoscience and innovative techniques of nanomedicine have moved micro/nanoparticles (MNPs) to the point of becoming actually useful for practical applications in the near future. Various differences between the extracellular and intracellular environments of cancerous and normal cells and the particular characteristics of tumors such as physicochemical properties, neovasculature, elasticity, surface electrical charge, and pH have motivated the design and fabrication of inventive "smart" MNPs for stimulus-responsive controlled drug release. These novel MNPs can be tailored to be responsive to pH variations, redox potential, enzymatic activation, thermal gradients, magnetic fields, light, and ultrasound (US), or can even be responsive to dual or multi-combinations of different stimuli. This unparalleled capability has increased their importance as site-specific controlled drug delivery systems (DDSs) and has encouraged their rapid development in recent years. An in-depth understanding of the underlying mechanisms of these DDS approaches is expected to further contribute to this groundbreaking field of nanomedicine. Smart nanocarriers in the form of MNPs that can be triggered by internal or external stimulus are summarized and discussed in the present review, including pH-sensitive peptides and polymers, redox-responsive micelles and nanogels, thermo- or magnetic-responsive nanoparticles (NPs), mechanical- or electrical-responsive MNPs, light or ultrasound-sensitive particles, and multi-responsive MNPs including dual stimuli-sensitive nanosheets of graphene. This review highlights the recent advances of smart MNPs categorized according to their activation stimulus (physical, chemical, or biological) and looks forward to future pharmaceutical applications.

Systemic inhibition and liver-specific over-expression of PAI-1 failed to improve survival in all-inclusive populations or homogenous cohorts of CLP mice

BACKGROUND

The role of plasminogen activator inhibitor type-1 (PAI-1) in abdominal sepsis remains elusive.

OBJECTIVES

To study the influence of inhibition and over-expression of PAI-1 upon survival in cecal ligation and puncture (CLP) sepsis.

METHODS

(i) Mice underwent moderate CLP and received 10 mg kg(-1) of either monoclonal anti-PAI-1 (MA-MP6H6) or control (MA-Control) antibody intravenously at 0, 18 or 30 h post-CLP. The 30-h treatment group was additionally stratified into mice predicted to survive (P-SUR) or die (P-DIE) based on IL 6 measured at 24 h post-CLP. (ii) PAI-1 expression was induced with pLIVE.PAI-1 plasmid administered 72 h pre-CLP. Blood was sampled for 5 days and survival was monitored for 28 days.

RESULTS

MA-MP6H6 effectively neutralized active PAI-1 and fully restored fibrinolysis while PAI-1 over-expression was liver-specific and correlated with PAI-1 increase in the blood. Without stratification, MA-MP6H6 co-/post-treatment conferred no survival benefit. Prospective stratification (IL-6 cut-off: 14 ng mL(-1) ) suggested increased mortality by MA-MP6H6 treatment in P-SUR that reached 30% difference (vs. MA-Control; P < 0.05) after a retrospective cut-off readjustment to 3.3 ng mL(-1) for better P-SUR homogeneity. Subsequent prospective anti-PAI-1 treatment in P-SUR mice with 3.3 ng mL(-1) cut-off demonstrated a negative but statistically insignificant effect: mortality was higher by 17% after MA-MP6H6 vs. MA-Control. Over-expression of PAI 1 did not alter post-CLP survival. Neither PAI-1 inhibition nor over-expression meaningfully modified inflammatory response and/or organ function.

CONCLUSIONS

Restoration of fibrinolysis in early abdominal sepsis was not beneficial and it may prove detrimental in subjects with the lowest risk of death, while preemptive PAI-1 up-regulation at the current magnitude was not protective.

Diagnosis of subclinical equine theileriosis in center of Iran using parasitological and molecular methods

A total of 105 blood samples from healthy horses from different stables in Yazd province, center of Iran, were examined for the presence of Theileria equi infection using parasitological and molecular methods. Out of the 105 samples, the parasitological method detected T. equi infection in 5 (4.76%) cases while the PCR method gave 24 (22.86%) positive results. Age, gender and breed were not determined as risk factors for T. equi infection in this study. Since blood samples were taken from healthy animals, this implies that 22.86% of horses had subclinical theileriosis in the current study. In conclusion, this study demonstrated that T. equi is present in horses in the center of Iran. Despite the healthy appearance of horses, these carrier animals can transmit the parasites to ticks and are a potential continuous source for maintaining and disseminating the organisms to the horse population. We concluded that it is important to make further studies on definitive host and vectors in the respective areas.

Klossiella equi in a donkey--a first case report from Iran

Klossiella equi is the only known and rarely reported coccidian parasite of the renal paranchyma of equids. An aged male donkey (Equus asinus asinus) was submitted to necropsy department of veterinary hospital. In histopathological study of renal sections different developmental stages of parasite were observed. These stages were as follow: Trophozoites, microgametes, macrogametes, sporont, budding sporont, sporoblasts, free sporoblasts, mature sporoblast and sporocyst. Parasitic infection with K. equi was encountered in the donkey. According to literature review this is the first report of donkey klossiellosis in Iran.

In vitro cultivation of axenic amastigotes and the comparison of antioxidant enzymes at different stages of Leishmania tropica

The present study aimed to establish a simple method to yield large amounts of Leishmania tropica amastigote-like forms in axenic cultures and to compare the superoxide dismutase (SOD) and glutathione peroxidase (GPX) enzymes at different stages of L. tropica. Different culture conditions were tested to find the optimum condition of axenic amastigotes generation. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were determined at logarithmic and stationary phases and axenic amastigote stage of the parasite. A high proportion (88%) of amastigote-like forms of L. tropica was observed in BHI medium supplemented with 20% FCS, pH 4.5, and incubated at 37ºC with 5% CO(2). The results showed that SOD activity was at the lowest level in the logarithmic phase of promastigotes and increased towards the stationary phase of promastigotes and amastigote stage. The results showed that the optimum condition for differentiation of L. tropica promastigotes to axenic amastigotes was BHI medium containing 20% FCS at pH 4.5, incubated at 37ºC in the presence of 5% CO(2). It seems that SOD, but not GPX is a major determinant of intracellular survival of the parasite.

Prevalence of Cryptosporidium infection in camels (Camelus dromedarius) in a slaughterhouse in Iran

Cryptosporidiosis is a zoonotic protozoan disease of worldwide distribution, affecting a wide range of vertebrate hosts. Most data on the biology, distribution pattern, pathology and prevalence of cryptosporidial infection in farm animals is restricted to cattle, sheep and goats. Limited data is available in other domestic herbivores including camel. Numerous camels (Camelus dromedarius) are raised in the semi-arid regions of Iran. Although camel is acknowledged as a potential source of contamination, little is known with regards to the prevalence of Cryptosporidium in this population except a case report on the occurrence of this infection in a bactrian camel (Camelus bactrianus) in China. This investigation was undertaken to determine the prevalence of Cryptosporidium infection in camels (C. dromedarius) from Najaf-Abad slaughterhouse, Isfahan Province, central part of Iran. Out of 103 faecal samples from 63 adult males and 40 adult females, 2-14 years old, 39 (37.9%) were found positive for oocysts. No significant differences were observed between males and females, and among different age groups. There was also no significant difference among infection intensity in different age groups. This is the first report of Cryptosporidium infection in camels from this country.

Occurrence and biology of goat warble fly infestation by Przhevalskiana silenus (Diptera, Oestridae) in Iran

Goat warble fly infestation (GWFI) by the larvae of Przhevalskiana silenus is endemic in goats of semi-hilly and mountainous regions of Iran. This myiasis has severe economic impact on tanning industries, and it is responsible for impaired milk and meat production, growth retardation and carcass depreciation. To estimate the prevalence of GWFI in the southern areas of Iran, from October 2006 to December 2008, the carcasses of 8000 goats at a Shiraz slaughterhouse and 1000 each at Marvdasht and Darab cities were examined weekly for the presence of P. silenus larvae. In addition, appropriate sections from the skin and subcutaneous tissues were processed for histopathological investigation. The prevalence rate of infestation in different cities varied from 7.0% to 18.9% and the minimum and maximum infestation rate was 3 and 78, with an average rate of infestation of 26.2 warbles per animal. Significant differences were observed in the prevalence among different age groups with no significant difference between male and female animals. First instar larvae (L(1)) were found on infected animals from early August to end of September, second larval stage (L(2)) from early October to end of November and third-stage larvae (L(3)) from early December to mid-March. No larvae were found on skin or subcutaneous tissues from end of March to late July. Live L(1) initiated mild lymphocyte, macrophage and eosinophil infiltration while dead L(1) initiated granulomatous or pyogranulomatous reactions. Live L(2) induced severe inflammatory reaction and massive tissue necrosis, which continued for L(3) and until the end of infestation phase. The subcutaneous tissues, dermis and epidermis became necrotic and fragmented, and L(3) penetrated the necrotic area to start its aerobic life cycle.

Prevalence and pathology of camel filariasis in Iran

A total of 1,070 camels of different ages and of both sexes slaughtered at Mashhad slaughterhouse were inspected for infection with Dipetalonema evansi. Microfilariae were found in peripheral blood smears of 221 (20.7%) camels (14% females and 23% males). In a second study, the testicles, epididymises, spermatic cords, and lungs of 197 male camels were examined, and 165 (83.7%) were infected with adult forms of D. evansi. Tissue sections from 30 infected and ten uninfected camels were collected and processed routinely for further histopathological studies. The arteries infected with D. evansi in the region of nodules in testis showed chronic reaction characterized by proliferative and hyperplastic changes of the endothelial and fibrous connective tissue layers, narrowing the lumen or occluding it. The testicles were either hypertrophic or atrophic and showed chronic orchitis with infiltration of lymphocytes, eosinophils, macrophages and fibroblasts, parenchymal degeneration, and necrosis and, in some cases, with hematoma and hydrocele formation. Necrosis of the alveolar walls, atelectasis, pulmonary edema, and fibrosis of the pulmonary parenchyma with chronic interstitial pneumonia and rarely mineralization of the wall of the blood vessels were also seen in some of the infected animals. D. evansi is highly endemic and constitutes an important health problem to camels in this area, resulting in high morbidity, impaired working capacity, and lowered productivity.

Is Third-Time Heart Retransplantation Justifiable?

Since repeat heart transplantation traditionally carries higher risk than primary engraftment, we tested the hypothesis that third-time cardiac allograft transplantation is associated with prohibitive mortality and morbidity. The cohort of all third-time cardiac retransplants performed at our institution (n=3) and reported to UNOS from 1987 to 2002 (n=10) was reviewed. The primary endpoints were early and late mortality. Extending the study frame through 2003 captures a total of 5 and 15 third-time heart transplant recipients in UCLA and UNOS databases, respectively. Of the 15 patients undergoing third-time retransplants, preoperatively one was ventricular assist device-dependent, four were on intravenous inotropes, and two had creatinine levels greater than 2.5. Additionally, four were male recipients of female donor hearts and the mean donor ischemic time was 2.6 hours. One patient was diagnosed with acute allograft rejection, 13 with coronary artery vasculopathy/chronic rejection, and one with primary graft failure. At our institution, five patients underwent a third heart transplant. There was no early or hospital mortality. One patient died late from transplant coronary artery disease and another following a fourth allograft. The mortality rate for third-time heart allograft recipients is acceptable. These results are influenced by small sample size, younger age, case selection, and operations at select, high-volume institutions with significant experience.

Plasma D-lactate as a potential early marker for colon ischaemia after open aortic reconstruction

BACKGROUND AND AIM

The breakdown of mucosal barrier function due to intestinal hypo-perfusion is the earliest dysfunction of ischaemic colitis. Severe colon ischaemia after aortic reconstruction is associated with mortality rates up to 90%. Therefore, early detection and treatment of patients with extensive ischaemic colitis is of crucial importance. In experimental studies, both D-lactate and bacterial endotoxin have been reported as markers of intestinal mucosal barrier impairment. However, evidence of their value in clinical practice is lacking. The aim of this pilot prospective cohort study was to assess the association between ischaemia of the colon (assessed histologically) and plasma levels of D-lactate and endotoxin in patients undergoing open aortic reconstruction.

PATIENTS AND METHODS

Twelve consecutive patients underwent surgery between February and April 2003. Six patients underwent emergency surgery and six patients elective aortic surgery. D-Lactate and endotoxin levels were measured in blood samples collected according to a standardised protocol. For histological examination biopsies were obtained by sigmoidoscopy on days 4-6 after surgery, or earlier if indicated clinically.

RESULTS

As early as 2 h postoperatively, elevated plasma levels of d-lactate were measured in patients with histologically proven ischaemic colitis. The peak of D-lactate elevation was on postoperative days 1 and 2. Concentration of plasma endotoxin was not significantly different in patients with or without ischaemic colitis.

CONCLUSION

Our data suggest that plasma D-lactate levels are a useful marker for early detection of ischaemic colitis secondary to aortic surgery.

Circulating S100B is increased after bilateral femur fracture without brain injury in the rat

BACKGROUND

S100B is an acknowledged marker of brain damage. However, trauma without brain damage also causes an increase in S100B. S100B concentrations are highest in multiple trauma patients with long bone fractures. Clinically, extensive long bone fractures are associated with haemorrhagic shock and haemorrhagic shock per se is associated with increased S100B. The aim of our experimental study was to verify the S100B increase in long bone fracture without haemorrhagic shock.

METHODS

and results. Bilateral femur fracture was carried out in 10 anaesthetized rats. Blood samples were drawn for immuno-luminometrical S100B measurement 5, 15, 30, 120, and 240 min after fracture. Mean arterial pressure (MAP), heart rate, and body temperature were monitored continuously. S100B increased after bilateral femur fracture and reached a peak 30-120 min after fracture (P<0.001). MAP remained at a level which is not associated with shock in rats. Heart rate and body temperature remained unchanged. Autopsy verified open bilateral femur fracture surrounded only by small zones of clotted blood.

CONCLUSIONS

S100B is increased in bilateral femur fracture without haemorrhagic shock in rats. This finding suggests that bone marrow is a potential extracerebral source of S100B.

Nitric oxide synthase-independent pathway(s) of nitric oxide formation after intestinal ischaemia–reperfusion

Background

Recent evidence suggests that nitric oxide produced in the gastrointestinal tract, in concert with other vasoactive mediators, plays an essential role in the regulation of splanchnic circulation.

Methods

To determine the sites and pathways of nitric oxide formation, electron paramagnetic resonance spectroscopy and the nitric oxide trap diethyldithiocarbamate-Fe were used to detect directly nitric oxide formed in intestine, liver and lungs of rats subjected to local intestinal ischaemia–reperfusion (I/R), in the presence or absence of nitric oxide donors or inhibitors. In addition, the role of nitric oxide in control of the gastrointestinal circulation was determined by means of a coloured microsphere technique employing N-(G)-Monomethyl-L-arginine (L-NMMA) in rats subjected to haemorrhagic shock followed by resuscitation.

Results

In contrast to remote organs lung and liver (no change), intestinal I/R resulted in an increase in nitric oxide formation in intestinal tissues. Administration of the non-specific nitric oxide inhibitor L-NMMA caused a decrease in I/R-independent basal nitric oxide levels in lung and liver but did not influence the I/R-induced increase in nitric oxide formation in intestinal tissues. In support of this, reverse transcriptase–polymerase chain reaction analyses showed inducible nitric oxide synthase (NOS) expression in the lung but not in intestinal tissues. In the microsphere experiment, a moderate and therapeutic dose of L-NMMA administered after the completion of resuscitation, which improved haemodynamic conditions and outcome, did not alter the intestinal circulation.

Conclusion

The data suggest that the early-phase I/R-induced nitric oxide formation in ischaemic intestinal tissue is probably NOS independent, while nitric oxide formation in normoxic remote tissues is partially NOS dependent. In addition, the authors' nitric oxide-related therapeutic approaches reveal that only the regulation of nitric oxide (e.g. nitric oxide supplementation during resuscitation or reperfusion and/or nitric oxide inhibition or modulation after resuscitation) may protect against hypovolaemic insults.

Mitochondria recycle nitrite back to the bioregulator nitric monoxide

Nitric monoxide (NO) exerts a great variety of physiological functions. L-Arginine supplies amino groups which are transformed to NO in various NO-synthase-active isoenzyme complexes. NO-synthesis is stimulated under various conditions increasing the tissue of stable NO-metabolites. The major oxidation product found is nitrite. Elevated nitrite levels were reported to exist in a variety of diseases including HIV, reperfusion injury and hypovolemic shock. Denitrifying bacteria such as Paracoccus denitrificans have a membrane bound set of cytochromes (cyt cd1, cyt bc) which were shown to be involved in nitrite reduction activities. Mammalian mitochondria have similar cytochromes which form part of the respiratory chain. Like in bacteria quinols are used as reductants of these types of cytochromes. The observation of one-e- divergence from this redox-couple to external dioxygen made us to study whether this site of the respiratory chain may also recycle nitrite back to its bioactive form NO. Thus, the aim of the present study was therefore to confirm the existence of a reductive pathway which reestablishes the existence of the bioregulator NO from its main metabolite NO2-. Our results show that respiring mitochondria readily reduce added nitrite to NO which was made visible by nitrosylation of deoxyhemoglobin. The adduct gives characteristic triplet-ESR-signals. Using inhibitors of the respiratory chain for chemical sequestration of respiratory segments we were able to identify the site where nitrite is reduced. The results confirm the ubiquinone/cyt be1 couple as the reductant site where nitrite is recycled. The high affinity of NO to the heme-iron of cytochrome oxidase will result in an impairment of mitochondrial energy-production. "Nitrite tolerance" of angina pectoris patients using NO-donors may be explained in that way.

Cytokine synthesis in the liver of endotoxin-tolerant and normal rats during hemorrhagic shock

In the present study the effects of endotoxin tolerance on hemorrhagic shock were investigated with particular focus on hepatic alterations. The following questions were addressed: (i) does hemorrhagic shock induce cytokine formation and heat shock response in the liver; and (ii) does endotoxin tolerance alter these reactions. Endotoxin tolerance was induced by repetitive daily injections of LPS for 5 days. Hemorrhagic shock was induced by hypovolemia (MAP 35 +/- 5 mmHg). After 3 h, the animals were resuscitated by re-infusion of homologous blood. m-RNA was isolated from liver biopsies and the mRNA levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-10 (IL-10) and heat shock protein 70 (HSP-70) were determined by RT-PCR. TNF-alpha was measured by ELISA in serum samples and in the supernatants of whole blood cultures. It was found that endotoxin tolerance reduced mortality caused by hemorrhagic shock from 80% to 20%. In parallel, TNF-alpha production in response to LPS in vivo and in vitro was significantly decreased. During hemorrhage and after resuscitation. increased mRNA levels were detected in hepatic biopsies for TNF-alpha, IL-6, IL-10 and HSP-70, with highest levels immediately after re-infusion. Endotoxin-tolerant rats produced significantly lower levels of TNF-alpha, while no differences were found for IL-10 and HSP-70. Within 30 min after reperfusion, significantly higher levels of IL-6 mRNA were found in hepatic biopsies from tolerant rats; these differences disappeared 2 h after reperfusion.

A unique murine monoclonal antibody recognizing HLA-B53, B37, B51, B52, +/-B44

Monoclonal antibodies have played an important role in studying the biochemistry of the HLA-Class I molecules. Some murine anti-HLA mAbs can identify configurations of HLA epitopes that have never been reported in human allosera. One of these configurations is identified by an IgM mAb designated as: BHA-1441. This antibody was produced using a lymphoblastoid cell line typed as: A*02, A*25; B*38, B*4402/4405; C*0501, C*07, BW4, as the immunogen. A lymphocytotoxicity test of this mAb over a panel of 109 frozen, 452 fresh and, later, 44 DNA typed T cells revealed its specificity as B53, 37, 51, 52, +/- 44. All of the antigens recognized by this mAb share the Bw4 motif at positions 81-83, except for the HLA-B37, which shares only 82L and 83R. Furthermore, while B37 and B44 cross-react due to the aspartic acid (D) substitution at position 156, the reactivity with B53, B5 (51,52), B37 and 60% of B44 cells, makes it unlikely that the target epitope could be due only to the primary amino-acid sequence. The antibody-binding site might involve changes in tertiary structure and peptides bound by the MHC. BHA-1441 is an interesting tool to study and type the HLA-B53 antigen and its cross-reactive epitopes.

Experimental evidence suggesting that nitric oxide diffuses from tissue into blood but not from blood into tissue

The aim of this study was to evaluate in vivo whether nitric oxide (NO) is able to diffuse from blood into tissues and vice versa from tissues into blood. We used an in vivo model of intestinal ischemia (superior mesenteric artery occlusion) selectively increasing NO levels in intestinal tissue and an infusion of L-arginine selectively increasing NO levels in blood. In this model we followed formation of nitrosyl complexes of hemoglobin (Hb-NO) in blood and nitrosyl-diethyldithiocarbamate-iron complexes (DETC--Fe--NO) in ischemic intestine and normoxic tissues by means of electron paramagnetic resonance spectroscopy. NO trapping by DETC--Fe in the tissues resulted in a reduction of Hb--NO levels in blood accompanied by the formation of water-insoluble DETC--Fe-NO complexes in ischemic intestine and normoxic tissues both during ischemia and during reperfusion. Administration of L-arginine increased NO levels in blood but neither in ischemic intestine nor in normoxic tissue. Our data suggest that NO released in blood from endothelial cells does not diffuse into tissue. In contrast, NO formed in tissue diffuses into blood. The latter indicates that NO formed in tissues may exert its biological activities systematically.

Organ specific formation of nitrosyl complexes under intestinal ischemia/reperfusion in rats involves NOS-independent mechanism(s)

Intestinal ischemia/reperfusion may lead to local and distant organ damage involving nitric oxide (NO). NO rapidly reacts with heme/non-heme-iron-yielding nitrosyl complexes, which can be determined directly by electron paramagnetic resonance spectroscopy. The aim of the present study was to characterize nitrosylation reactions induced by transient intestinal ischemia in blood and tissues. We used electron paramagnetic resonance spectroscopy and reverse transcription polymerase chain reaction analyses to estimate nitrosyl complex levels and inducible NO synthase mRNA expression in rats subjected to superior mesenteric artery occlusion for 60 min followed by the reperfusion. Nitrosyl hemoglobin concentrations in circulating blood were significantly increased during ischemia and reperfusion. Nitrosyl hemoglobin complexes were detected in ischemic intestine, but not in normoxic lung and liver or reperfused intestine. Administration of N-G-monomethyl-L-arginine, a non-specific NO synthase inhibitor, did not affect the formation of circulating nitrosyl complexes. Moreover, inducible NO synthase mRNA was not found in intestinal tissues at 30 min of reperfusion. Our data suggest an organ-specific NO formation indicated by the increased nitrosylation reaction in ischemic intestinal tissue, but not in the distant normoxic organs, in spite of high circulating nitrosyl hemoglobin levels. NO involved in nitrosylation under intestinal ischemia/reperfusion is probably formed by NO synthase-independent mechanism(s).

Purification and characterization of beta-methylaspartase from Fusobacterium varium

Beta-methylaspartase (EC 4.3.1.2) was purified 20-fold in 35% yield from Fusobacterium varium, an obligate anaerobe. The purification steps included heat treatment, fractional precipitation with ammonium sulfate and ethanol, gel filtration, and ion exchange chromatography on DEAE-Sepharose. The enzyme is dimeric, consisting of two identical 46 kDa subunits, and requires Mg2+ (Km = 0.27+/-0.01 mM) and K+ (Km = 3.3+/-0.8 mM) for maximum activity. Beta-methylaspartase-catalyzed addition of ammonia to mesaconate yielded two diastereomeric amino acids, identified by HPLC as (2S,3S)-3-methylaspartate (major product) and (2S,3R)-3-methylaspartate (minor product). Optimal activity for the deamination of (2S,3S)-3-methylaspartate (Km = 0.51+/-0.04 mM) was observed at pH 9.7. The N-terminal protein sequence (30 residues) of the F. varium enzyme is 83% identical to the corresponding sequence of the clostridial enzyme.

Endochondral ossification of costal cartilage is arrested after chondrocytes have reached hypertrophic stage of late differentiation

Late cartilage differentiation during endochondral bone formation is a multistep process. Chondrocytes transit through a differentiation cascade under the direction of environmental signals that either stimulate or repress progression from one step to the next. In human costal cartilage, chondrocytes reach very advanced stages of late differentiation and express collagen X. However, remodeling of the tissue into bone is strongly repressed. The second hypertrophy marker, alkaline phosphatase, is not expressed before puberty. Upon sexual maturity, both alkaline phosphatase and collagen X activity levels are increased and slow ossification takes place. Thus, the expression of the two hypertrophy markers is widely separated in time in costal cartilage. Progression of endochondral ossification in this tissue beyond the stage of hypertrophic cartilage appears to be associated with the expression of alkaline phosphatase activity. Costal chondrocytes in culture are stimulated by parathyroid hormone in a PTH/PTHrP receptor-mediated manner to express the fully differentiated hypertrophic phenotype. In addition, the hormone stimulates hypertrophic development even more powerfully through its carboxyterminal domain, presumably by interaction with receptors distinct from PTH/PTHrP receptors. Therefore, PTH can support late cartilage differentiation at very advanced stages, whereas the same signal negatively controls the process at earlier stages.

Mitochondria recycle nitrite back to the bioregulator nitric monoxide

Nitric monoxide (NO) exerts a great variety of physiological functions. L-Arginine supplies amino groups which are transformed to NO in various NO-synthase-active isoenzyme complexes. NO-synthesis is stimulated under various conditions increasing the tissue of stable NO-metabolites. The major oxidation product found is nitrite. Elevated nitrite levels were reported to exist in a variety of diseases including HIV, reperfusion injury and hypovolemic shock. Denitrifying bacteria such as Paracoccus denitrificans have a membrane bound set of cytochromes (cyt cd1, cyt bc) which were shown to be involved in nitrite reduction activities. Mammalian mitochondria have similar cytochromes which form part of the respiratory chain. Like in bacteria quinols are used as reductants of these types of cytochromes. The observation of one-e- divergence from this redox-couple to external dioxygen made us to study whether this site of the respiratory chain may also recycle nitrite back to its bioactive form NO. Thus, the aim of the present study was therefore to confirm the existence of a reductive pathway which reestablishes the existence of the bioregulator NO from its main metabolite NO2-. Our results show that respiring mitochondria readily reduce added nitrite to NO which was made visible by nitrosylation of deoxyhemoglobin. The adduct gives characteristic triplet-ESR-signals. Using inhibitors of the respiratory chain for chemical sequestration of respiratory segments we were able to identify the site where nitrite is reduced. The results confirm the ubiquinone/cyt be1 couple as the reductant site where nitrite is recycled. The high affinity of NO to the heme-iron of cytochrome oxidase will result in an impairment of mitochondrial energy-production. "Nitrite tolerance" of angina pectoris patients using NO-donors may be explained in that way.