Protection against lethal polymicrobial sepsis by CNI-1493, an inhibitor of pro-inflammatory cytokine synthesis

Polymicrobial sepsis caused by cecal ligation and puncture (CLP) in mice produces the inflammatory and pathological sequelae of lung neutrophil infiltration, adult respiratory distress syndrome (ARDS) and death. These sequelae are dependent upon the synergistic interaction between several inflammatory mediators, including tumor necrosis factor (TNF), interleukin 1 (IL-1 ), and nitric oxide (NO). The overlapping spectrum of multiple mediator toxicity has hampered efforts to develop therapies for sepsis based on selective inhibition of a single mediator. Therefore, we tested the hypothesis that inhibition of multiple pro-inflammatory mediators would abrogate lethality. Our results show that administration of a tetravalent guanylhydrazone compound (CNI-1493) protected mice against 10 day mortality in CLP. Evidence of suppression of the cytokine cascade was given by decreased serum levels of TNF and IL-6 in CNI-1493 treated animals (TNF reduced 60% as compared to controls; IL-6 reduced 90% compared to controls; P < 0.05), and decreased levels of the acute-phase protein serum amyloid A response measured 24 h after CLP. Serum nitrites/nitrates, which give an index of NO production, were also significantly reduced (50%). Protection against CLP induced lung damage was observed as attenuation of edema and alveolar neutrophil infiltration, suppression of pulmonary TNF levels, and reduction of TUNEL-positive staining in lung. We conclude that CNI-1493 effectively inhibits the synthesis of multiple pro-inflammatory mediators and protects against death during polymicrobial sepsis.

[Relevance of personal contextual factors of the ICF for use in practical social medicine and rehabilitation]

Personal contextual factors play an essential part in the model of the International Classification of Functioning, Disability and Health (ICF). The WHO has not yet classified personal factors for global use although they impact on the functioning of persons positively or negatively. In 2010, the ICF working group of the German Society of Social Medicine and Prevention (DGSMP) presented a proposal for the classification of personal factors into 72 categories previously arranged in 6 chapters. Now a positioning paper has been added in order to stimulate a discussion about the fourth component of the ICF, to contribute towards a broader and common understanding about the nature of personal factors and to incite a dialogue among all those involved in health care as well as those people with or with-out health problems in order to gain a comprehensive perspective about a person's condition.

[Frequency and causes of civil and criminal proceedings in radiology. Analysis of a survey]

The eagerness of German patients to go to court on account of actual or suspected malpractice of their physicians has increased over the years, as is the case in other Western countries. Media coverage has given rise to criticism of physicians and their services rendered more than before. This naturally also concerns the discipline of radiology, even though the probability of a radiologist being accused in a lawsuit is clearly minor in comparison to the surgical disciplines. In contrast to other fields, the X-ray pictures are always available for a second opinion. In this study, 4760 radiologists were sent a questionnaire by mail and 1503 answered. The questionnaires were evaluated regarding interrogative and informative data from pending or completed proceedings. Lawsuits were directed towards the assessment of examinations (38%), the actual performance of an examination (30%) and not towards providing patients with information as we had expected. Angiographies, mammographies, and radiographies were the most frequent reasons for instituting proceedings. The majority of litigating patients was between 40 and 50 years old. The proceedings led to civil convictions in 30% and criminal convictions in 5.5%. Of the physicians accused of incorrect conduct, 73% were of the opinion that they had been treated unjustly, 26% supported the reproach as justified, and the rest had formed no opinion. Physicians in private practice and senior consultants (70%) were most frequently sued.

Design and evaluation of immunotoxicity studies

The evaluation of potential adverse effects of pharmaceuticals on the immune system is part of the standard drug development procedures and needs to be available prior to the start of phase III clinical trials. Although the histopathological assessment of lymphoid organs/tissues is considered fundamental for the identification and characterization of immunotoxic reactions, additional investigations are now recommended by the European guidelines for repeated-dose toxicity testing of medicinal products in order to achieve an accurate assessment of immune system functionality with regard to immunomodulation. In the present paper, we describe and discuss a study design which permits the investigation of the immune function in a 4-week study in rats following immunization by subcutaneous administration of the T-dependent antigen Keyhole Limpet Hemocynin (KLH). This includes assessment of hematology parameters, titration of KLH-specific antibodies in serum, lymphocyte immunophenotyping in blood, thymus, spleen and lymph nodes, macroscopic pathology and histopathological evaluation of the lymphatic organs/tissues and of the injection sites.

An European inter-laboratory validation of alternative endpoints of the murine local lymph node assay: First round

The new OECD guideline 429 (skin sensitization: local lymph node assay) is based upon a protocol, which utilises the incorporation of radioactivity into DNA as a measure for cell proliferation in vivo. The guideline also enables the use of alternative endpoints in order to assess draining lymph node (LN) cell proliferation. Here we describe the first round of an inter-laboratory validation of alternative endpoints in the LLNA conducted in seven laboratories. The validation study was managed and supervised by the Swiss Agency for Therapeutic Products, Swissmedic. Statistical analyses of all data were performed by an independent centre at the University of Bern, Department of Statistics. Ear-draining, LN weight and cell count were used to assess proliferation instead of radioactive labeling of lymph node cells. In addition, the acute inflammatory skin reaction was measured by ear swelling and weight of circular biopsies of the ears to identify skin irritating properties of the test items. Hexylcinnamaldehyde (HCA) and three blinded test items were applied to female, 8--10 weeks old NMRI and BALB/c mice. Results were sent via the independent study coordinator to the statistician. The results of this first round showed that the alternative endpoints of the LLNA are sensitive and robust parameters. The use of ear weights added an important parameter assessing the skin irritation potential, which supports the differentiation of pure irritative from contact allergenic potential. There were absolute no discrepancies between the categorisation of the three test substances A--C determined by each single participating laboratories. The results highlighted also that many parameters do have an impact on the strength of the responses. Therefore, such parameters have to be taken into consideration for the categorisation of compounds due to their relative sensitizing potencies.

An European inter-laboratory validation of alternative endpoints of the murine local lymph node assay

The original local lymph node assay (LLNA) is based on the use of radioactive labelling to measure cell proliferation. Other endpoints for the assessment of proliferation are also authorized by the OECD Guideline 429 provided there is appropriate scientific support, including full citations and description of the methodology (OECD, 2002. OECD Guideline for the Testing of Chemicals; Skin Sensitization: Local Lymph Node Assay, Guideline 429. Paris, adopted 24th April 2002.). Here, we describe the outcome of the second round of an inter-laboratory validation of alternative endpoints in the LLNA conducted in nine laboratories in Europe. The validation study was managed and supervised by the Swiss Agency for Therapeutic Products (Swissmedic) in Bern. Ear-draining lymph node (LN) weight and cell counts were used to assess LN cell proliferation instead of [3H]TdR incorporation. In addition, the acute inflammatory skin reaction was measured by ear weight determination of circular biopsies of the ears to identify skin irritation properties of the test items. The statistical analysis was performed in the department of statistics at the university of Bern. Similar to the EC(3) values defined for the radioactive method, threshold values were calculated for the endpoints measured in this modification of the LLNA. It was concluded that all parameters measured have to be taken into consideration for the categorisation of compounds due to their sensitising potencies. Therefore, an assessment scheme has been developed which turned out to be of great importance to consistently assess sensitisation versus irritancy based on the data of the different parameters. In contrast to the radioactive method, irritants have been picked up by all the laboratories applying this assessment scheme.

Determination of the effect of calcineurin inhibitors on the rat's immune system after KLH immunisation

The calcineurin inhibitors cyclosporin A (CsA), tacrolimus (FK506) and pimecrolimus (ASM981) are on the market for the oral treatment of psoriasis and atopic dermatitis and topical treatment of atopic dermatitis, respectively. The effect of these treatments on the immune response was investigated in this study after immunisation of rats with keyhole limpet hemocyanin (KLH). Male rats (10 per group) were orally administered pimecrolimus at 10 or 30 mg/kg/day), tacrolimus at 3 mg/kg/day or CsA at 20 mg/kg/day for 4 weeks. Control animals similarly received the vehicle only. The last five animals per group were immunised and challenged with KLH on days 16 and 24, respectively. Eight days after the last injection, the immune function was investigated by detecting KLH-specific antibodies in the serum and by examination of cell infiltration at the site of the KLH-challenge. In addition, a correlation between functional and structural changes was established by quantification of lymphocyte sub-populations in the blood or residing in lymphatic tissue. In KLH-immunised rats, CsA caused complete suppression of the KLH-specific IgM and IgG production, whereas only IgG production was affected by pimecrolimus at 30 mg/kg/day and more so by tacrolimus at 3 mg/kg/day. Immunophenotyping of lymphocyte sub-populations in spleen and lymph node indicated a decrease in T lymphocytes with pimecrolimus at 30 mg/kg/day, tacrolimus and CsA, whereas these changes were marginal for pimecrolimus at 10 mg/kg/day. Immunophenotyping of peripheral white blood cells (WBC) revealed a decrease in the absolute number of T lymphocytes with all three test items. In comparison with non-immunised animals, a slight increase in absolute numbers of T lymphocytes was observed in KLH-immunised animals treated with pimecrolimus at 10 or 30 mg/kg/day. In conclusion, the ability of the immune system to respond to KLH was not affected by pimecrolimus at 10 mg/kg/day whereas a decrease in immune function was noted in the other groups as follows: pimecrolimus (30 mg/kg/day) < tacrolimus (3 mg/kg/day) < CsA (20 mg/kg/day).

Validation of immune function testing during a 4-week oral toxicity study with FK506

Assessment of the immune system's capability to respond to antigens with the generation of specific antibodies, whilst under the influence of a test article, is required in toxicity tests according to the European guideline for repeated dose toxicity testing of medicinal products. The purpose of this study in rats was to validate methodology for the determination of Keyhole Limpet Haemocyanin (KLH)-specific antibodies under the influence of an immunologically active compound. The immunosuppressant FK506, commercially available as Prograf, was administered orally (gavage) to five rats per sex per group at dosages of 0.5mg/kg per day or 3mg/kg per day, for a period of 4 weeks. On days 14 and 22, KLH was administered subcutaneously, with an adjuvant (AluGel), to the two treated groups and a control (i.e. without FK506 treatment) approximately 1h following administration of FK506. Terminal investigations included haematology parameters, titration of KLH-specific antibodies in serum (ELISA), macroscopic pathology, spleen and thymus weights, immunophenotyping of splenocytes (FACS analysis) and histopathology of the lymphatic tissues. At 3mg/kg per day a minimal reduction of subcutaneous KLH-induced granuloma formation and a moderate to marked reduction of germinal centre development (axillary lymph node and spleen) were observed. Reduced CD4+ (T-cell) counts were found in the spleen of males, consistent with a suppressed production of KLH-specific antibodies (IgG in both sexes, IgM in males only) and a higher incidence of atrophy in the periarteriolar lymphoid sheaths of males. Slight-to-moderate lymphopenia was present in both sexes at 3mg/kg per day. These findings are consistent with the known pharmacological activity of FK506. In conclusion, determination of antibody titres following immunisation of rats with KLH, with concurrent exposure to a drug, appears to be a valid method in the context of the immunotoxicity evaluation required by European regulation.

[Successful direct transfer of a deep frozen-thawed equine embryo]

Embryos were flushed on day 7 after ovulation from two mares, and frozen using a conventional slow freezing procedure in phosphate buffered (PBS) saline supplemented with 10% FCS, 1.5 mol/L ethylene glycol and 0.25 mol/L sucrose. One of the two embryos was thawed after 10 months of storage in liquid nitrogen and transferred directly (without dilution of the cryoprotectant and quality examination) to a synchronized recipient. This transfer resulted in the birth of a live female foal. To our knowledge, this is the first live foal born after direct transfer of a frozen-thawed equine embryo.

Cytokine expression profiles during murine contact allergy: T helper 2 cytokines are expressed irrespective of the type of contact allergen

We have investigated the cytokine response pattern following sensitisation (induction) of BALB/c mice with different chemicals (dinitrochlorobenzene, dinitrofluorobenzene, oxazolone, glutaraldehyde, formaldehyde, trimellitic anhydride, croton oil) and elicitation (challenge) of contact allergy in sensitised animals. The results of our investigations showed that different chemicals induced both T helper (Th) 1 cytokines [interleukin (IL) 2, interferon beta (IFNgamma) [corrected] and Th2 cytokines (IL-4, IL-10) at different stages during murine contact allergy. We also confirmed our previous findings that IL-4 and IL-10 release were up-regulated during the challenge phase regardless the contact allergen used, whereas the release of IFNgamma [corrected] did not show a clear preference for being up- or down-regulated. In our hands, the increased expression of Th2 cytokines after challenge exposure to contact allergens appeared as a stable marker of secondary contact allergenic responses. Quantitative differences in the expression of IL-4 were observed between different contact allergens. The present results clearly indicate that skin sensitisers were able to elicit cytokine response patterns, which could not be related to a clear-cut Th1 or Th2 type of cytokine response. Furthermore, dermal application of contact allergens produced different kinetics of cytokine secretion upon induction and challenge. In our hands, the co-expression of Th1 and Th2 type cytokines appeared as a universal consequence of dermal application of contact allergens to responsive mice. Our results indicate that co-expression of Th1 and Th2 cytokines during contact allergy is an important feature of murine contact allergy in responsive mice and that chemicals differ in their potency to induce the expression of these cytokines. Furthermore, the results do not support the view that different chemicals induce Th1 or Th2 cytokines in a mutually exclusive manner depending on their preference for inducing either contact or respiratory allergy. The results are expected to renew the discussion about the usefulness of the Th1/Th2 paradigm in certain areas of immunotoxicology.

Pharmaceutical intervention of advanced glycation endproducts

Recent studies have revealed that reducing sugars, such as glucose, react with proteins through non-enzymatic glycosylation to form irreversible, covalently cross-linked proteins known as advanced glycation endproducts (AGEs). Furthermore, it has been demonstrated that this naturally occurring process, accelerated in diabetics due to hyperglycaemia, impairs biological functions leading to cardiovascular disorders, as well as diabetic and age-related complications. Pharmaceutical intervention to prevent or reverse these complications have focused on inhibiting the formation of AGEs by compounds such as dimethyl-3-phenacylthiazolium chloride or breaking the glucose derived cross-links by selective cleavage. Intervention targeted at AGE cross-links in vivo offers a way to interfere with age-related changes of tissues.

Protein glycation, diabetes, and aging

Biological amines react with reducing sugars to form a complex family of rearranged and dehydrated covalent adducts that are often yellow-brown and/or fluorescent and include many cross-linked structures. Food chemists have long studied this process as a source of flavor, color, and texture changes in cooked, processed, and stored foods. During the 1970s and 1980s, it was realized that this process, called the Maillard reaction or advanced glycation, also occurs slowly in vivo. Advanced glycation endproducts (AGEs) that form are implicated, causing the complications of diabetes and aging, primarily via adventitious and crosslinking of proteins. Long-lived proteins such as structural collagen and lens crystallins particularly are implicated as pathogenic targets of AGE processes. AGE formation in vascular wall collagen appears to be an especially deleterious event, causing crosslinking of collagen molecules to each other and to circulating proteins. This leads to plaque formation, basement membrane thickening, and loss of vascular elasticity. The chemistry of these later-stage, glycation-derived crosslinks is still incompletely understood but, based on the hypothesis that AGE formation involves reactive carbonyl groups, the authors introduced the carbonyl reagent aminoguanidine hydrochloride as an inhibitor of AGE formation in vivo in the mid 1980s. Subsequent studies by many researchers have shown the effectiveness of aminoguanidine in slowing or preventing a wide range of complications of diabetes and aging in animals and, recently, in humans. Since, the authors have developed a new class of agents, exemplified by 4,5-dimethyl-3-phenacylthiazolium chloride (DPTC), which can chemically break already-formed AGE protein-protein crosslinks. These agents are based on a new theory of AGE crosslinking that postulates that alpha-dicarbonyl structures are present in AGE protein-protein crosslinks. In studies in aged animals, DPTC has been shown to be capable of reverting indices of vascular compliance to levels seen in younger animals. Human clinical trials are underway.

Intralaboratory validation of alternative endpoints in the murine local lymph node assay for the identification of contact allergic potential: primary ear skin irritation and ear-draining lymph node hyperplasia induced by topical chemicals

We validated a two-tiered murine local lymph node assay (LLNA) with a panel of standard contact (photo)allergens and (photo)irritants with the aim of improving the discrimination between contact (photo) allergenic potential and true skin (photo)irritation potential. We determined ear weights to correlate chemical-induced skin irritation with the ear-draining lymph node (LN) activation potential. During tier I LLNAs, a wide range of concentrations were applied on three consecutive days to the dorsum of both ears. Mice were exposed to UVA light immediately after topical application to determine the photoreactive potential of some test chemicals. Mice were killed 24 h after the last application to determine ear and LN weights and LN cell counts. It was possible to classify the tested chemicals into three groups according to their threshold concentrations for LN activation and skin irritation: (1) chemicals with a low LN activation potential and no or very low skin irritation potential; (2) chemicals with a marked LN activation potential higher than a distinct skin irritation potential; and (3) chemicals with LN activation potential equal to or lower than their skin irritation potential. Group 1 consisted only of contact allergens, indicating that LN activation in the absence of skin irritation points to a contact allergenic activity. Since groups 2 and 3 comprised irritants and contact allergens, a tier II LLNA protocol was used to finally differentiate between true irritants and contact allergens. Briefly, mice were pretreated with mildly to moderately irritating concentrations of the chemical to the shaved back and after 12 days were challenged on the ears as described above in order to elicit a contact allergenic response in the ear skin and the ear-draining LN. With this approach, tier II LLNAs have to be conducted only in cases for which skin irritation potential is in the range of LN activation potential and no structure-activity relationship data indicating a contact allergenic hazard are available.

Release of mast cell tryptase from human colorectal mucosa in inflammatory bowel disease

BACKGROUND

Histologic detection of mast cells cannot adequately reflect their function and state of activation, since degranulated mast cells may escape from histologic assessment. To better define the role of mast cells in inflammatory bowel disease, the spontaneous secretion of mast cell tryptase, a highly mast cell specific protease, was measured from colorectal samples.

METHODS

After detection of the initial basal tryptase release, gut mucosal samples were incubated in a modified Hanks/RPM1 medium using a mucosa oxygenation system. Spontaneous tryptase secretion from 153 viable samples of 22 controls, 30 patients with Crohn disease (CD) and 19 with ulcerative colitis (UC) was followed over 4 h. Tryptase was measured by radioimmunoassay.

RESULTS

The rates of the initial basal tryptase release revealed that mast cell activation occurs during active inflammation in CD and UC. While the time course of tryptase release was similar in all three groups, spontaneous tryptase secretion (over 4 h) was found to be significantly enhanced and prolonged only in UC (P < 0.01 compared to controls), but not in CD.

CONCLUSIONS

This study provides clear evidence from viable endoscopic colorectal samples that mast cell mediators were secreted during active inflammation in CD and UC. However, the extent of mast cell involvement and activation differs considerably between CD and UC. Significantly increased rates of tryptase secretion were found both in non-inflamed and inflamed tissue of UC, indicating that mast cell involvement is a typical feature of UC.

A cross-link breaker has sustained effects on arterial and ventricular properties in older rhesus monkeys

Nonenzymatic glycosylation and cross-linking of proteins by glucose contributes to an age-associated increase in vascular and myocardial stiffness. Some recently sythesized thiazolium compounds selectively break these protein cross-links, reducing collagen stiffness. We investigated the effects of 3-phenacyl-4,5-dimethylthiazolium chloride (ALT-711) on arterial and left ventricular (LV) properties and their coupling in old, healthy, nondiabetic Macaca mulatta primates (age 21 +/- 3.6 years). Serial measurements of arterial stiffness indices [i.e., aortic pulse wave velocity (PWV) and augmentation (AGI) of carotid arterial pressure waveform] as well as echocardiographic determinations of LV structure and function were made before and for 39 weeks after 11 intramuscular injections of ALT-711 at 1.0 mg/kg body weight every other day. Heart rate, brachial blood pressure, and body weight were unchanged by the drug. PWV and AGI decreased to a nadir at 6 weeks [PWV to 74.2 +/- 4.4% of baseline (B), P = 0.007; AGI to 41 +/- 7.3% of B, P = 0.046], and thereafter gradually returned to baseline. Concomitant increases in LV end diastolic diameter to 116.7 +/- 2.7% of B, P = 0.02; stroke volume index (SV(index)) to 173.1 +/- 40.1% of B, P = 0.01; and systolic fractional shortening to 180 +/- 29.7% of B, P = 0.01 occurred after drug treatment. The LV end systolic pressure/SV(index), an estimate of total LV vascular load, decreased to 60 +/- 12.1% of B (P = 0.02). The LV end systolic diameter/SV(index), an estimate of arterio-ventricular coupling, was improved (decreased to 54.3 +/- 11% of B, P < 0.002). Thus, in healthy older primates without diabetes, ALT-711 improved both arterial and ventricular function and optimized ventriculo-vascular coupling. This previously unidentified cross-link breaker may be an effective pharmacological therapy to improve impaired cardiovascular function that occurs in the context of heart failure associated with aging, diabetes, or hypertension, conditions in which arterial and ventricular stiffness are increased.

Comparison of clinical pathology parameters with two different blood sampling techniques in rats: retrobulbar plexus versus sublingual vein

Blood samples were taken from the retrobulbar venous plexus or the sublingual vein of male HamIbm:Wist rats to compare clinical pathology parameters between the two sampling techniques. By analogy with a pharmacokinetic study, blood was sampled six times during one day from unfasted animals. After 3 weeks of recovery, blood was taken from fasted animals on a single occasion. In addition, prolactin and corticosterone levels were determined to compare stress-related effects between the two sampling methods. Body weight development and food consumption were similar after single as well as after repeated blood sampling for the two blood sampling techniques. Haemotological evaluation showed a gradual decrease in erythrocyte count, haemoglobin concentration and haematocrit after repeated blood sampling. Repeated withdrawal of blood samples over 24 h corresponding to approximately 22% of the total blood volume resulted in a decrease in red blood cell parameters by up to 30%. The withdrawal of approximately 10% of the total blood volume was associated with a decrease in these parameters by up to 10% and should not be exceeded for animal welfare reasons and to allow a reliable evaluation of data in a study. Repeated blood sampling was associated with an initial decrease in the number of white blood cells, mainly due to a reduction in lymphocytes; white blood cell counts were slightly increased one day after. The decrease in lymphocytes and the increase in neutrophils after repeated sampling were generally slightly more pronounced in the blood from the retrobulbar plexus than from the sublingual vein. Comparison of serum clinical chemistry data showed significantly higher activities of creatine kinase and aspartate aminotransferase in samples from the retrobulbar plexus. These findings suggest a higher degree of tissue damage with blood sampling from the retrobulbar plexus than from the sublingual vein. Despite a large inter-individual variability, higher mean values of prolactin on each occasion and corticosterone after a single sample in fasted animals indicate a higher stress associated with blood sampling from the retrobulbar plexus.

Expression of mRNAs encoding for two different olfactory receptors in a subset of olfactory receptor neurons

Evidence has accumulated to support a model for odorant detection in which individual olfactory receptor neurons (ORNs) express one of a large family of G protein-coupled receptor proteins that are activated by a small number of closely related volatile chemicals. However, the issue of whether an individual ORN expresses one or multiple types of receptor proteins has yet to be definitively addressed. Physiological data indicate that some individual ORNs can be activated by odorants differing substantially in structure and/or perceived quality, suggesting multiple receptors or one nonspecific receptor per cell. In contrast, molecular biological studies favor a scheme with a single, fairly selective receptor per cell. The present studies directly assessed whether individual rat ORNs can express multiple receptors using single-cell PCR techniques with degenerate primers designed to amplify a wide variety of receptor sequences. We found that whereas only a single OR sequence was obtained from most ORNs examined, one ORN produced two distinct receptor sequences that represented different receptor gene families. Double-label in situ hybridization studies indicated that a subset of ORNs co-express two distinct receptor mRNAs. A laminar segregation analysis of the cell nuclei of ORNs labeled with the two OR mRNA probes showed that for one probe, the histogram of the distribution of the cell nuclei along the depth of the epithelium was bimodal, with one peak overlapping the (unimodal) histogram for the other probe. These results are consistent with co-expression of two OR mRNAs in a population of single ORNs.

Significance of resting and stimulated cerebral blood flow for predicting the risk of hemodynamic cerebral ischemia in a model of chronic hemodynamic insufficiency

OBJECTIVE

It has been postulated that patients with a compromised cerebrovascular reserve capacity (RC), defined as cerebral blood flow (CBF) response to acetazolamide (ACZ) (by percent), are at higher risk for ischemic stroke. The value of CBF and RC for predicting the risk of hemodynamically induced impairment of cerebral function is examined.

METHODS

Both common carotid arteries were occluded in 22 Wistar-Kyoto rats. Thirty-one days later, mean arterial blood pressure was reduced to 40 mm Hg for 30 minutes. Laser Doppler scanning of CBF at resting conditions and after intraperitoneal administration of ACZ (0.1 mg/g body weight) was performed 30 minutes and 28 days after occlusion as well as before and during hypotension. Memory and motor functions were examined before and after CBF measurements.

RESULTS

After occlusion, CBF dropped significantly and ACZ did not increase CBF. Four weeks later, resting CBF had significantly improved but remained impaired, as did RC, showing a distinct interindividual variability. Hypotension reduced CBF by 57 +/- 4% (P < 0.001) and significantly impaired memory and motor functions. CBF during hypotension correlated with resting CBF before hypotension (r = 0.495, P = 0.027) and with CBF before (r = 0.392, P = 0.048) and after (r = 0.476, P = 0.034) ACZ, as determined 4 weeks after occlusion. There was no correlation with RC (r = 0.091, P = 0.702). Neurological tests performed 1 day after hypotension correlated with CBF during hypotension (memory function, P = 0.03; motor function, P = 0.02) but not with RC.

CONCLUSION

In this model of chronic hemodynamic insufficiency, the risk of impairment to global cerebral function was predicted by resting CBF and CBF after ACZ but not by RC determined with ACZ.

An advanced glycation endproduct cross-link breaker can reverse age-related increases in myocardial stiffness

Decreased elasticity of the cardiovascular system is one of the hallmarks of the normal aging process of mammals. A potential explanation for this decreased elasticity is that glucose can react nonenzymatically with long-lived proteins, such as collagen and lens crystallin, and link them together, producing advanced glycation endproducts (AGEs). Previous studies have shown that aminoguanidine, an AGE inhibitor, can prevent glucose cross-linking of proteins and the loss of elasticity associated with aging and diabetes. Recently, an AGE cross-link breaker (ALT-711) has been described, which we have evaluated in aged dogs. After 1 month of administration of ALT-711, a significant reduction ( approximately 40%) in age-related left ventricular stiffness was observed [(57.1 +/- 6.8 mmHg x m(2)/ml pretreatment and 33.1 +/- 4.6 mmHg x m(2)/ml posttreatment (1 mmHg = 133 Pa)]. This decrease was accompanied by improvement in cardiac function.

Primary immune response in skin and skin-associated lymphoid tissue of interleukin-4 transgenic mice

The interleukin-4 transgenic mice investigated here exhibit a ubiquitous expression of interleukin-4 in all organs, including the skin. In this study, the induction phase of oxazolone-induced local primary contact hypersensitivity and croton oil-induced irritant contact dermatitis in transgenic and wild-type mice was analysed. Compared to wild-type mice, the transgenic mice showed a decreased activation of the skin-draining lymph nodes but a strong hyperreactivity in the skin after topical sensitisation. In contrast to this, both the transgenic and the wild-type mice developed a strong and comparable inflammatory skin reaction after topical irritation. A striking increased expression level of tumour necrosis factor-alpha and macrophage inflammatory protein-2 genes were found in the skin of the transgenic mice during primary local contact hypersensitivity, while both the transgenic and the wild-type mice developed comparable expression levels of these cytokines during irritant contact dermatitis. Compared to wild-type mice, a strongly enhanced expression level of interleukin-6 transcripts derived from epidermal antigen presenting cells were detected in the skin of IL-4 transgenic mice, whereas in the skin-draining lymph nodes of transgenic mice significantly lower levels were detected. We conclude that the migration of epidermal antigen-presenting cells towards the skin-draining lymph nodes is reduced in transgenic mice, which could be due to the different cytokine balance in these mice strains. The atypical irritant-like reaction observed in transgenic mice after topical sensitisation is a phenomenon comparable to atopic diseases and therefore this transgenic strain might be a helpful model for investigating the immunopathophysiological features of these diseases.

Modulation of the activity of human monocyte-derived dendritic cells by chemical haptens, a metal allergen, and a staphylococcal superantigen

For the development of mechanistic assays in immunotoxicology, the phenotype, cytokine production, and stimulatory function of dendritic cells (DCs) were assessed after incubation with the chemical haptens aminophenol, chlorpromazine hydrochloride, dinitrochlorobenzene (DNCB), and with the DNCB-corresponding tolerogen DCNB, the metal allergen nickel sulfate, the irritants sodium dodecyl sulfate and benzoic acid, as well as with staphylococcal enterotoxin B (SEB) and lipopolysaccharide (LPS). DCs were differentiated from human monocytes by in vitro exposure to GM-CSF and interleukin-4 (IL-4) for 7 days. Flow cytometric data revealed that only representative haptens increased the surface expression of HLA-DR, CD86, CD40, and of CD54 on DCs when compared to irritants or to the tolerogen. This event was associated with an increased ability of DCs to stimulate T cell proliferation. Moreover, after incubation with the haptens, but not with the irritants or the tolerogen, a higher production of TNF-alpha by DCs was observed. Under our experimental conditions, no release of IL-1beta, IL-10, or IL-12 was detected. Compared to the activation elicited by haptens, SEB strongly up-regulated HLA-DR and costimulatory molecule expression. In agreement with this effect, there was a marked release of TNF-alpha and a slight production of IL-12. IL-1beta and IL-10 were not detected in the culture medium. Finally, SEB-pulsed DCs showed a strong T-cell-stimulating activity. These data underline the activating potential of haptens versus irritants or a tolerogen on DC functions. The different levels of DC activation by haptens and SEB suggested that distinct cellular events were involved.

CT guided interstitial high dose rate brachytherapy for recurrent malignant gliomas

This paper describes the technique and preliminary results of high dose rate (HDR) interstitial brachytherapy for recurrent grade III and grade IV gliomas. Although in the initial treatment of malignant gliomas brachytherapy has been shown to give better results than external beam therapy, this has previously always been with low dose rate (LDR) brachytherapy. Stereotactic frames are used for interstitial LDR brachytherapy but a CT image-guided technique does not require such a frame. The survival rates for our initial 53 patients do not significantly differ from LDR results. However, using HDR there are several advantages, including a much shorter treatment time with HDR than LDR and better patient comfort. HDR also allows better individualized optimization of the treatment than LDR.

A figurative measure of subjective hunger sensations

In an attempt to better characterize the subjective experience of hunger, we assessed the locus and extent of sensations associated with varying degrees of hunger. In the first study, 83 subjects indicated by marking on a drawing of a human figure where they felt hungry under hypothetical conditions of slight to extreme hunger. Approximately 55% of subjects indicated an abdominal locus with slight hunger, a proportion which increased somewhat with increasing levels of imagined hunger. The proportion of subjects indicating other or additional body sites grew significantly with increasing hunger states; for example, those identifying the head region increased from about 10-35%. In a second study, 14 subjects were fasted for 22 h and then refed. Using the drawn figures, they outlined body areas where they experienced hunger during and after fasting. The size of the abdominal area and the total body area associated with hunger sensations expanded with increasing food deprivation and contracted after refeeding. The size of the area of hunger sensation did not necessarily correlate with the degree of hunger as assessed by standard rating scales. The results indicate that the extent and locus of hunger sensations vary with fasting and feeding, and suggest that the site and size of the body areas associated with hunger sensations may provide qualitative and quantitative measures of the subjective experience of hunger not captured by analogue rating scales.

Inhibition of advanced glycation endproduct formation by acetaldehyde: role in the cardioprotective effect of ethanol

Epidemiological studies suggest that there is a beneficial effect of moderate ethanol consumption on the incidence of cardiovascular disease. Ethanol is metabolized to acetaldehyde, a two-carbon carbonyl compound that can react with nucleophiles to form covalent addition products. We have identified a biochemical modification produced by the reaction of acetaldehyde with protein-bound Amadori products. Amadori products typically arise from the nonenzymatic addition of reducing sugars (such as glucose) to protein amino groups and are the precursors to irreversibly bound, crosslinking moieties called advanced glycation endproducts, or AGEs. AGEs accumulate over time on plasma lipoproteins and vascular wall components and play an important role in the development of diabetes- and age-related cardiovascular disease. The attachment of acetaldehyde to a model Amadori product produces a chemically stabilized complex that cannot rearrange and progress to AGE formation. We tested the role of this reaction in preventing AGE formation in vivo by administering ethanol to diabetic rats, which normally exhibit increased AGE formation and high circulating levels of the hemoglobin Amadori product, HbA1c, and the hemoglobin AGE product, Hb-AGE. In this model study, diabetic rats fed an ethanol diet for 4 weeks showed a 52% decrease in Hb-AGE when compared with diabetic controls (P < 0.001). Circulating levels of HbA1c were unaffected by ethanol, pointing to the specificity of the acetaldehyde reaction for the post-Amadori, advanced glycation process. These data suggest a possible mechanism for the so-called "French paradox," (the cardioprotection conferred by moderate ethanol ingestion) and may offer new strategies for inhibiting advanced glycation.

Early changes in murine epidermal cell phenotype by contact sensitizers

In order to develop an in vitro predictive assay for the detection of contact sensitizers, we investigated the possible modulation of the expression of cell-surface molecules in the early phases of treatment of murine epidermal cells (EC) with known contact sensitizers. After in vitro treatment of Balb/c EC with the strong contact sensitizer, TNBS, Langerhans cells (LCs) demonstrated a rapid up-regulation of CD45, CD40, CD32/16 (Fc gamma RII/III) and CD23 (Fc epsilon RII) molecules. CD45 and CD40 were also rapidly up-regulated on the dendritic epidermal T cells. Interestingly, after treatment with this severe sensitizer, a marked induction of CD40 expression was found on a CD45 negative population, most probably keratinocytes. In contrast to these cell-surface molecules, I-Ad/I-Ed and CD90.2 expression were unchanged. No change was observed on the expression of CD45 and CD40 after treatment with a mild or a weak contact sensitizer, citral and citronellal respectively. In contrast, like TNBS, they up-regulated the expression of CD32/16 and CD23 on LCs. The irritant sodium dodecyl sulfate had no effect on all these cell-surface molecules. Our results indicated that in vitro, chemicals with allergic potential induced early specific phenotype changes that may represent an early-activated state of the cells. This state may be responsible for initiating the afferent phase of contact sensitivity in vivo. Based on these findings, it might be possible to develop an in vitro assay to reduce the number of experimental animals for a fast screening of contact sensitizers and for discriminating between mild contact sensitizers and irritants.

Topical FK506 suppresses cytokine and costimulatory molecule expression in epidermal and local draining lymph node cells during primary skin immune responses

Recently, it has been shown that the immunosuppressive macrolide lactone, FK506, exerts good therapeutic efficacy in inflammatory skin diseases. The aim of this study was to analyze the influence of topical FK506 on molecular (IL-1alpha, IL-1beta, IL-2, IL-4, IL-12 p35, IL-12 p40, macrophage inflammatory protein-2 (MIP-2), granulocyte-macrophage CSF (GM-CSF), TNF-alpha, and IFN-gamma) and cellular (I-A+/CD80+, I-A+/CD54+, I-A+/CD69+, I-A+/B220+, and CD4+/CD25+) events in epidermal (EC) and local draining lymph node (LNC) cells during primary contact hypersensitivity responses. Cytokine mRNA levels for IL-1alpha, IL-1beta, GM-CSF, TNF-alpha, MIP-2, and IFN-gamma in EC and for IL-2, IL-4, IL-12 p35, IL-12 p40, and IFN-gamma in LNC were increased and resulted in significant LNC proliferation during oxazolone-induced contact hypersensitivity. Topical FK506 treatment dose-dependently suppressed oxazolone-induced LNC proliferation. This effect was correlated with decreased IL-1alpha, IL-1beta, GM-CSF, TNF-alpha, MIP-2, and IFN-gamma mRNA expression within the epidermis and decreased IL-12 p35 and p40 mRNA expression in LNC. Further analysis of the LNC cytokine pattern revealed that the production of both Thl (IFN-gamma and IL-2) and Th2 (IL-4) cytokines was dramatically impaired after topical FK506 treatment. Flow cytometric analysis showed that topical FK506 decreased the population of epidermis-infiltrating CD4+ T cells and suppressed the expression of CD54 and CD80 on I-A+ EC and LNC during hapten-induced contact hypersensitivity. Furthermore, topical FK506 profoundly impaired oxazolone-induced up-regulation of CD25 expression on CD4+ LNC and dramatically decreased hapten-induced expansion of I-A+/B220+ and I-A+/CD69+ LNC subsets. In conclusion, these results give new insights into the mechanisms of action of topical FK506 treatment.

CNI-H0294, a nuclear importation inhibitor of the human immunodeficiency virus type 1 genome, abrogates virus replication in infected activated peripheral blood mononuclear cells

Active nuclear importation of the human immunodeficiency virus (HIV) type 1 (HIV-1) preintegration complex (PIC) is required for the productive infection of nondividing cells, but it is believed to be dispensable for the infection of proliferating cells, such as activated T lymphocytes. To investigate this question, we exploited the properties of the small arylene bis (methyl ketone) compound CNI-H0294. We have previously shown that this compound associated with the HIV-1 matrix protein nuclear localization sequence and blocked binding of the HIV-1 PIC to yeast karyopherin alpha. CNI-H0294 abrogated nuclear importation of the HIV-1 genome in macrophages and effectively inhibited infection of nondividing cells. In this study we demonstrate that CNI-H0294 inhibits binding of the HIV-1 PIC to human karyopherin alpha and reduces nuclear importation of the viral genome in primary peripheral blood mononuclear cells (PBMCs). We also demonstrate that CNI-H0294 inhibits acute infection of PBMC cultures in vitro with a primary isolate of HIV-1 and reduces virus replication and virus load in cultures of endogenously infected PBMCs from seropositive individuals. Thus, as for infection of nondividing, terminally differentiated macrophages, HIV-1 uses active nuclear importation of the virus genome to infect activated CD4+ T cells. These results support nuclear importation as a novel target and CNI-H0294 and its derivatives as novel compounds for therapeutic intervention in HIV infection and AIDS.

Breakers of advanced glycation end products restore large artery properties in experimental diabetes

Glucose and other reducing sugars react with proteins by a nonenzymatic, posttranslational modification process called nonenzymatic glycation. The formation of advanced glycation end products (AGEs) on connective tissue and matrix components accounts largely for the increase in collagen crosslinking that accompanies normal aging and which occurs at an accelerated rate in diabetes, leading to an increase in arterial stiffness. A new class of AGE crosslink "breakers" reacts with and cleaves these covalent, AGE-derived protein crosslinks. Treatment of rats with streptozotocin-induced diabetes with the AGE-breaker ALT-711 for 1-3 weeks reversed the diabetes-induced increase of large artery stiffness as measured by systemic arterial compliance, aortic impedance, and carotid artery compliance and distensibility. These findings will have considerable implications for the treatment of patients with diabetes-related complications and aging.

[Surgical strategy in cases of multiple aneurysms]

Over a 4 year period 50 patients (34 women, 16 men; median age 48.5 years, range 24-69 ys.) were operated on multiple intracranial aneurysms (MA) and 283 patients (178 women, 105 men, median age 50.0 years; range 22-82 ys.) on single aneurysms (SA). A subarachnoid hemorrhage (SAH) occurred in the MA-group (in total 123 aneurysms, 5 giant aneurysms) in 43 cases, in the SA-group in 257 cases. Fifty-seven percent of all patients were operated on within 48 hours after SAH, 14% between day 3 and 7, 29% after day 7. There were no significant differences in the Hunt & Hess grading or in the distribution of ruptured aneurysms between both groups. Operation time was longer by 70 min in MA-patients than in SA-patients, but did not significantly influence the outcome in that group (rs = 0.200; p = 0.163). In 74% of the patients all aneurysms could be eliminated in one stage, among them 18 had bilateral or supra-infratentorial aneurysms. The step by step occlusion of the aneurysms was performed by dissecting all aneurysms and by clipping the deepest one and the bleeding source first. In 8 cases, all aneurysms were clipped through a contralateral keyhole approach.--After a mean follow up period of 1 year, 72% of the MA-patients and 65% of the SA-patients had made an excellent or good recovery. The morbidity rate was 22% in the MA- and 30% in the SA-patients. The operative mortality amounted to 6% in the MA- and 5% in the SA-group. The differences in outcome of both groups were not significant. Considering a bleeding risk of 1-2% per year, we suggest the operative treatment of all identified aneurysms, if possible in a one-stage, if necessary in a two-stage procedure in an individually tailored approach.

Role of cyclophilin A in the uptake of HIV-1 by macrophages and T lymphocytes

Cyclophilins are a family of proteins that bind cyclosporin A (CsA) and possess peptidyl-prolyl cis-trans isomerase activity. In addition, they are secreted by activated cells and act in a cytokine-like manner, presumably via signaling through a cell surface cyclophilin receptor. More recently, host-derived cyclophilin A (CyPA) has been shown to be incorporated into HIV-1 virions and its incorporation essential for viral infectivity. Here we present evidence supporting a role for viral-associated CyPA in the early events of HIV-1 infection. We report that HIV-1 infection of primary peripheral blood mononuclear cells can be inhibited by: (i) an excess of exogenously added CyPA; (ii) a CsA analogue unable to enter the cells; (iii) neutralizing antibodies to CyPA. Taken together with our observations that recombinant CyPA-induced mobilization of calcium in immortalized, as well as primary, CD4+ T lymphocytes, and that incubation of T cells with iodinated CyPA, followed by chemical cross-linking, resulted in the formation of a high molecular mass complex on the cell surface, these results suggest that HIV-1-associated CyPA mediates an early event in viral infection via interaction with a cellular receptor. This interaction may present a target for anti-HIV therapies and vaccines.

A modified murine local lymph node assay for the differentiation of contact photoallergy from phototoxicity by analysis of cytokine expression in skin-draining lymph node cells

Since predictive differentiation of photoallergenic from phototoxic reactions, induced by low molecular weight compounds, represents a current problem, we tried to improve the differentiation between the two reactions by using a modified protocol of the local lymph node assay (LLNA). Briefly, groups of female BALB/c mice received compound solution or vehicle alone on the dorsum of both ears on 3 consecutive days. Immediately after compound application indicated groups of mice were exposed to a UVA light-dose of 10 J/cm2. Auricular lymph nodes draining the ear tissue were excised 24 h following the last exposure. Evaluation consisted of assessing lymph node weights and cell counts to monitor organ hyperplasia and in vivo-proliferative events following substance application. Furthermore, we analysed cytokine gene transcription in freshly prepared lymph node cells (LNC) and the cytokine release in vitro by restimulated CD4+ T-cells and antigen presenting cells (APC), both purified from the skin-draining lymph nodes. Both contact (photo) allergenic (oxazolone and tetrachlorosalicylanilide) and phototoxic substances (8-methoxypsoralen and acridine) caused a dose dependent increase in lymph node weights and cell counts pointing to an inflammatory process in the lymph nodes. Analysis of cytokine gene transcription ex vivo and cytokine release in vitro revealed that during the induction phase of contact (photo) allergy CD4+ T-cells produced IL-2 and IFN-gamma as well as IL-4 and IL-10, whereas IL-6 was derived from APC. In contrast, phototoxic reactions caused only an upregulation of IL-2 and IFN-gamma. Furthermore, we demonstrate that the release of IL-4 and IL-10 by CD4+ T-cells was clearly increased, whereas IL-6 and IFN-gamma expression was reduced or not changed following a challenge with contact (photo) allergens revealing an allergy-indicative shift in cytokine expression. In conclusion, our results show that contact photoallergenic reactions could be differentiated from phototoxic events by analysis of LNC cytokine expression patterns.

Small molecule inhibition of tumor necrosis factor gene processing during acute pancreatitis prevents cytokine cascade progression and attenuates pancreatitis severity

The morbidity and mortality associated with acute pancreatitis are primarily a result of pancreatic parenchymal necrosis and the development of marked pulmonary dysfunction. Recent evidence suggests that both of these conditions are propagated by interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha, which are produced in large quantities within these organs. Because the generation of these cytokines occurs in a predictable manner early in the development of acute pancreatitis, we aimed to determine whether cytokine gene processing could be inhibited in vivo and what effects this would have on pancreatitis severity. Mild [caerulein, 50 micrograms/kg/hour intraperitoneally (IP) x 4; n = 40] or severe (choline-deficient diet; n = 40) necrotizing pancreatitis was induced in NIH swiss mice. Animals were randomly given a novel small molecule (CNI-1493; 10 mg/kg IP) known to inhibit macrophage production of TNF and IL-1 in vitro by inhibiting translation of TNF mRNA into protein. Control animals received IP vehicle. All animals with acute pancreatitis showed dramatic up-regulation of the IL-1 beta and TNF-alpha genes. Those animals receiving CNI-1493 demonstrated attenuated production of both species of mRNA in pancreatic as well as pulmonary tissue (P < 0.01). Markers of pancreatitis severity such as serum amylase and lipase, as well as pancreatic necrosis, were decreased in animals treated with CNI-1493 (all P < 0.05). Posttranscriptional blockade of TNF production precludes induction of the proinflammatory cytokine cascade that normally occurs during acute pancreatitis. This lack of cytokine gene processing in the pancreas and lungs results in dramatic reductions in tissue damage and pancreatitis severity, which is not model dependent. This is the first time that a small molecule has been shown to influence this disease.

Targeted suppression of cytokine production in monocytes but not in T lymphocytes by a tetravalent guanylhydrazone (CNI-1493)

Image analysis was used to study the cytokine-inhibitory effect of the nitric oxide inhibitor tetravalent guanylhydrazone (CNI-1493) in individual immunocytochemically stained human peripheral blood mononuclear cells (PBMC). CNI-1493 inhibited lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-alpha, interleukin (IL)-1alpha, IL-1beta, IL-6, and IL-8 production whether or not LPS stimulation was enhanced by interferon (IFN)-gamma priming. Addition of TNF-alpha to CNI-1493-exposed LPS-stimulated cells partially restored the incidence of IL-1alpha-, IL-1beta-, and IL-8-producing cells. TNF-alpha production induced by costimulation by ligation of CD3 and CD28 was inhibited by CNI-1493 in monocytes but not in T lymphocytes. The prevalence of IL-2-, IFN-gamma-, and TNF-beta-producing T cells was not reduced by CNI-1493. Phorbol ester and ionomycin activation also resulted in a CNI-1493 -induced inhibition of TNF-alpha in monocytes but resistant production of TNF-alpha, IL-2, and IFN-gamma by T cells. Thus, CNI-1493 preferentially inhibited synthesis of proinflammatory cytokines in monocytes.

Studies on the mechanism of antimalarial action of a novel arylene bis(methylketone)

2-Amino-4-(3,5-diacetylphenyl)amino-1,6-dimethylpyrimidinium chloride (CNI-H0294) is a novel arylene bis(methylketone) compound that displays antimalarial activity against chloroquine- and pyrimethamine-resistant Plasmodium falciparum clones. The compound has been found to be concentrated into infected erythrocytes, with 80-179 microM accumulated when parasites were cultured in the presence of 1.0 microM CNI-H0294. Uninfected erythrocytes, in contrast, only accumulated 2.5-3.4 microM CNI-H0294 under identical conditions. Using postmitochondrial supernatants from a number of parasite clones, the compound was found to inhibit dihydrofolate reductase (EC 1.5.1.3) activity with an IC50 of 243-483 microM. Thus, while CNI-H0294 is not a powerful inhibitor of plasmodial dihydrofolate reductase, the accumulation of the compound into infected erythrocytes, when correlated to the external ED50 concentration against parasite growth in vitro, reaches concentrations sufficient to inhibit the malarial enzyme.