The role of hydrogen peroxide in the contractile response to angiotensin II

In the last years, reactive oxygen species (ROS) have been proposed as mediators of proliferative/hypertrophic responses to angiotensin II (Ang II), both in vivo and in vitro. However, the hypothesis that the Ang II-dependent cell contraction could be mediated by ROS, particularly H2O2, has not been tested. Present experiments were devoted to test this hypothesis and to analyze the possible mechanisms involved. Catalase (CAT) prevented the increased myosin light chain phosphorylation and the decreased planar cell surface area (PCSA) induced by 1 microM Ang II in cultured rat vascular smooth muscle cells (VSMC). This preventive effect of CAT was also detected when 1 microM platelet-activating factor (PAF) was used as a contractile agonist instead of Ang II. Similar results were found when using horseradish peroxidase as an H2O2 scavenger or cultured rat mesangial cells. In vascular smooth muscle cells, CAT modified neither the binding of labeled Ang II nor the Ang II-induced inositol 1,4,5-trisphosphate (IP3) synthesis. However, it completely abolished the Ang II-dependent calcium peak, in a dose-dependent fashion. CAT-loaded cells (increased intracellular CAT concentration over 3-fold) did not show either a decreased PCSA or an increased intracellular calcium concentration after Ang II treatment. Ang II stimulated the H2O2 synthesis by cultured cells, and the presence of CAT in the extracellular compartment significantly diminished the Ang II-dependent increased intracellular H2O2 concentration. The physiological importance of these findings was tested in rat thoracic aortic rings: CAT prevented the contraction elicited by Ang II. In summary, present experiments point to H2O2 as a critical intracellular metabolite in the regulation of cell contraction.

Immunopathogenesis of cholestatic autoimmune liver diseases

Primary biliary cirrhosis and primary sclerosing cholangitis are well recognized chronic cholestatic liver diseases that are considered to have an autoimmune basis. Recent progress in the study of autoimmune liver diseases has improved the recognition and characterization of these conditions. An important component of this progress has been the identification of liver disease-associated autoantibodies and their respective target antigens, and the development of specific assays for these autoantibodies. In addition, some nonhumoral immunological findings imply an involvement of specific immunopathogenic mechanisms in the development of these conditions. Furthermore, immunogenetic factors associated with increased susceptibility to some of these diseases have been identified. This article reviews the most relevant information relating to the postulated autoimmune pathogenesis of these diseases, with special emphasis on their associated humoral and cellular immunological abnormalities and immunopathogenetic factors. Some of the remaining important unresolved issues relating to the pathogenesis of these diseases, that need to be addressed in further research, are highlighted.

Microsurgical reconstruction of the hypoplastic thumb, type IIIB

If a classically hypoplastic thumb, type IIIA, presenting with a first carpometacarpal joint, is amenable to reconstruction, a type IIIB case without the basal joint, is classically treated by pollicization. The authors concur with this opinion, but found two circumstances in which reconstruction is an option in a type IIIB thumb, either when an adolescent asks for improvement of an unstable but utilized thumb, or when a parent definitely refuses pollicization. In such cases, a free, vascularized metatarsophalangeal joint is the first step of the reconstruction, followed by classic non-microsurgical steps. The authors reviewed five cases, with a mean follow-up of 7.8 years. Hypoplasia of the reconstructed thumb, and a limited pinch, allow this option only with restricted indications.

Regulation of absorption and ABC1-mediated efflux of cholesterol by RXR heterodimers

Several nuclear hormone receptors involved in lipid metabolism form obligate heterodimers with retinoid X receptors (RXRs) and are activated by RXR agonists such as rexinoids. Animals treated with rexinoids exhibited marked changes in cholesterol balance, including inhibition of cholesterol absorption and repressed bile acid synthesis. Studies with receptor-selective agonists revealed that oxysterol receptors (LXRs) and the bile acid receptor (FXR) are the RXR heterodimeric partners that mediate these effects by regulating expression of the reverse cholesterol transporter, ABC1, and the rate-limiting enzyme of bile acid synthesis, CYP7A1, respectively. Thus, these RXR heterodimers serve as key regulators of cholesterol homeostasis by governing reverse cholesterol transport from peripheral tissues, bile acid synthesis in liver, and cholesterol absorption in intestine.

Simple closure or vagotomy and pyloroplasty for the treatment of a perforated duodenal ulcer: comparison of results

BACKGROUND/AIMS

Treatment of the perforated duodenal ulcer continues to be a controversial subject. The purpose of our study was to compare the results of simple closure of perforated duodenal ulcer versus treatment by truncal vagotomy and pyloroplasty.

METHODS

We present a prospective and randomized study of 207 patients who underwent surgical treatment due to perforated duodenal ulcer. In 117 patients the surgical treatment was simple closure and postsurgery medical treatment with proton pump inhibitors for 1 month, and in 90 patients vagotomy and pyloroplasty with no additional medical treatment.

RESULTS

We applied the Visick scale in order to compare postsurgery results. The postoperative morbidity and mortality rates were the same with both techniques. Statistically, in both cases, no significant differences were found in postsurgery symptomatology. The different rates of recurrent ulcers and the reinterventions due to recurrent ulcers presented no significant statistical values.

CONCLUSION

We conclude that simple closure remains the selected treatment in the majority of patients who present with a perforated duodenal ulcer. The operation is a simple and safe procedure.

[Value of a new first web space reconstruction in congenital hand deformities. A study of 54 patients]

INTRODUCTION

Only a few studies are available in the literature on the specific problem of the congenital contracture or absence of the first web in hand deformities, and first web reconstruction.

MATERIAL AND METHODS

Sixty-seven first web plasties in 54 patients were retrospectively analyzed: they included 44 cases of classical plasties, i.e., Z-plasty (21 cases); dorsal flap plasty of the index (19 cases), thumb (1 case), or the hand (10 cases), and 16 cases of' pseudo-kite flap.

RESULTS

The results were difficult to assess, as the syndromes were dissimilar and the deformities were not comparable (e.g., Apert syndrome versus Poland syndrome). However, it was found that the 'pseudo-kite' technique which was applicable to certain cases resulted in a web extension of 3.2 cm without any deepening.

DISCUSSION

No method of classical assessment can be used to comprehensively evaluate the results of first web reconstruction due to the wide variability in clinical characteristics, the lack of patient cooperation in this young age group, the possible MPJ articular thumb instability, and growth factors. Although 4-flap Z-plasty is an adequate technique for non-severe first web deformities, the 'pseudo-kite' flap approach is useful in more severe cases. In 13 cases, a peroperative measurement before and following plasty was made, and a significant increase (205%) in planimetric and stereotactic gain compared to pre-plasty findings was noted.

CONCLUSION

It does not seem logical to have a particular preference for a certain approach when considering first web reconstruction in congenital malformations. Each technique has its advantages and disadvantages, depending on patient age, the type of malformation, the state of the thumb, the extent of the first web deformity and the possible presence of scar tissue.

[Classification and treatment of symbrachydactyly. A series of 117 cases]

In the present study, a modification has been proposed of the Blauth and Gekeler classification, aimed at a more accurate definition of appropriate surgical treatment. An analysis was made of a series of 120 cases of symbrachydactyly (117 patients); however, surgery was only performed in 86 cases (51 toe transfers in 49 patients; mean age at surgery 12 months). Type I included the separation of short and sometimes stiff fingers; type II, the 'pseudo-cleft', could be subdivided into three groups. Type IIA included those hands with more than two long and frequently hypoplastic digits, regarding which a decision had to be made between removal of rudimentary fingers or their stabilization. In type IIB, hand function was good and surgery was rarely needed. Type III (monodactylous) could also be subdivided into two categories, i.e., normal thumb in type IIIA and hypoplasia in IIIB. Finally, in type IVA, toe transfer surgery was performed on condition that wrist mobility was sufficient to compensate for the insufficient mobility of the artificial thumb on the anterior aspect of the radius. In all cases, a weak but useful pincer movement was obtained, with poor cosmetic results. In the case of toe transfers, surgery was advocated before the age of one year; and although mobility was disappointing (35 degrees active motion), good growth and excellent discrimination (5 mm on average) was observed. Symbrachydactyly is a fairly frequent congenital malformation; its diverse clinical features require a precise classification to better determine adequate treatment management.

Strategies to antagonise the cyclosporine A-induced proliferation of human pulmonary artery smooth muscle cells: anti-endothelin-1 antibodies, verapamil, and octreotide

The present study investigated the mechanisms mediating the actions of the immunosuppressive drug cyclosporine A (CsA) on human pulmonary artery smooth muscle cell (PASMC) proliferation. The new hydroxyethyl derivative of D-serine(8)-cyclosporine, SDZ IMM 125, was used for comparison. CsA-induced proliferation was determined by incorporation of [(3)H]thymidine ([(3)H]Thy). CsA in the concentration range between 0.1 nM and 0.1 microM induced a concentration-dependent increase in proliferation after 24, 48, and 72 hr of incubation. Higher CsA concentrations were cytotoxic. When proliferation experiments were performed in the presence of a monoclonal antibody against endothelin-1 (ET-1), CsA-induced proliferation was totally inhibited. No inhibition occurred in the presence of the same antibody when heat-inactivated or a non-specific monoclonal antibody. In parallel, CsA increased the production of ET-1, as determined by radioimmunoassay. Incubation of PASMCs with ET-1 at the concentration range at which the latter was released by CsA induced cell proliferation. The somatostatin derivative Sandostatin (SDT; octreotide), which is an inhibitor of the growth of smooth muscle cells as well as a potent inhibitor of ET-1 secretion, inhibited both the CsA-induced ET-1 release and the increase in [3H]Thy incorporation by PASMCs. A similar effect was observed for the calcium channel blocker verapamil (VP). SDZ IMM 125 induced weaker effects than CsA in terms of PASMC proliferation and ET-1 secretion. In conclusion, CsA increased the rate of proliferation of PASMCs, while SDZ IMM 125 induced a weaker effect. Anti-ET-1 antibody, VP, and SDT significantly inhibited CsA-induced PASMC proliferation.

A glycoconjugate from corms of saffron plant (Crocus sativus L.) inhibits root growth and affects in vitro cell viability

A glycoconjugate has been characterized from saffron corms (Crocus sativus L.) that inhibits the growth of roots of Nicotiana tabacum and Arabidopsis thaliana, at concentrations ranging from 1-100 micrograms m-3. Roots of seedlings grown in the presence 0.1 microgram m-3 glycoconjugate showed bulging of epidermal cells, whereas at 10 micrograms m-3, roots were completely devoid of hairs. At 100 micrograms m-3 glycoconjugate the cell walls of the root vascular tissues were thicker and, overall, the vascular tissue was enlarged. In addition, this glycan is cytotoxic to isolated tobacco cells and protoplasts, with 50% cell death induced by 0.5 and 2 micrograms m-3 glycoconjugate, respectively. Morphological and biochemical changes induced by the exposure to the glycoconjugate included cell size decrease, loss of regular cell shape, cytoplasm collapse, and release of intracellular proteins. This molecule at low concentrations (0.1 microgram m-3) mimics the effects of Yariv phenylglycosides and of mutant Arabidopsis which present defective or missing arabinogalactan-proteins (AGPs) in roots, indicating the glycoconjugate might interact with cell surface AGPs.

Use of human skin equivalent Apligraf for in vitro assessment of cumulative skin irritation potential of topical products

The main goal of the present study was to investigate the response of the human skin equivalent Apligraf in vitro to the application of irritant substances and its predictivity as a screening tool for cumulative skin irritant potential in humans. Vaseline, calcipotriol, trans-retinoic acid, and sodium lauryl sulfate were applied to Apligraf in vitro for 24 h. Cell viability (lactate dehydrogenase leakage), release and mRNA expression of the proinflammatory cytokines IL-1alpha and IL-8, and morphological changes were assessed. The same products were applied to 30 healthy volunteers in a double-blind, randomized, vehicle-controlled within-subject study. The skin reactions after repeated 24-h applications over 3 weeks under Finn chamber patches were monitored by visual scoring and biophysical methods (trans-epidermal water loss, chromametry, and blood flow). Sodium lauryl sulfate was cytotoxic to Apligraf, and increased the release and expression of cytokines at low (0.2%, 0. 4%), but not at high (0.8%, 1%) concentrations. It induced severe irritancy in vivo. Trans-retinoic acid increased the expression and release of cytokines with no detectable cytotoxicity and showed moderate irritancy in humans. Although calcipotriol did neither affect cell viability nor the production of cytokines, it induced morphological signs of irritation and was mildly irritant for healthy volunteers. Vaseline was innocuous in vivo and induced no changes in Apligraf. In conclusion, the cumulative skin irritation potential of the tested products could be predicted with Apligraf in a sensitive and specific manner, by monitoring cytotoxicity, proinflammatory cytokines, and morphological changes.

Effects of glutamine on head and neck squamous cell carcinoma

Glutamine supplements are being studied as protectants against the mucositis associated with radiation therapy of head and neck squamous cell carcinoma. Glutamine is an important amino acid for the maintenance of healthy gut function and nitrogen transport. It is also a preferred energy source for many types of tumors through an altered Krebs cycle. The effects of glutamine supplements on the growth of head and neck squamous cell carcinoma have not been studied. Eighteen nude mice were implanted with one established cell line, and 18 were implanted with another. The mice were paired and fed either a glutamine-rich or a glutamine-poor diet. There was not a statistically significant difference in the growth rates of the xenografts or in the weight gain of the mice between the diet groups. These findings are encouraging for the continued use of glutamine supplements in patients with head and neck squamous cell carcinoma.

In vitro models to study mechanisms involved in cyclosporine A-mediated glomerular contraction

The immunosuppressive drug, cyclosporin A (CsA), which is successfully used to prevent rejection in organ transplantation, induces renal side-effects as shown by a decrease in glomerular filtration rate and ultrafiltration coefficient regulated by the tone of mesangial cells.The aim of the present study was to investigate the effect of CsA on isolated glomeruli and mesangial cells, which constitute appropriate in vitro models for renal vasoreactivity studies. The roles of different intracellular and extracellular mediators such as calcium, endothelin-1 (ET-1), prostaglandins (TXA(2 )and PGI(2)) and reactive oxygen intermediates (ROIs) were analysed. CsA caused a concentration- and time-dependent decrease in the planar cross-sectional areas of isolated glomeruli and mesangial cells as determined by image analysis. Intracytosolic free calcium concentration determined by fluorimetric analysis was significantly increased after 30 min CsA (10 microM) incubation. In the contraction experiment, the calcium antagonist verapamil inhibited the CsA response. ET-1, TXB(2) and keto-PGF(1alpha) were determined directly, however no changes were found statistically significantly different from respective controls. In contrast to these results, the ET-1 specific antibody was able to reduce CsA-mediated cell contraction. In the presence of a prostacyclin agonist iloprost, CsA-induced contraction was also modified. The role of ROIs using a 2'7'-dichlorofluorescein diacetate (DCFdAc) fluorimetric method was directly determined by observing, with 10 microM CsA, a significant production of hydrogen peroxide (H(2)O(2)), which was able alone to induce mesangial cell contraction. Coincubation with the antioxidants led to a significant inhibition of mesangial cell contraction. These results suggest that CsA caused an imbalance in the normal level of all investigated vasoconstrictive and vasodilator mediators, which shifted towards the advantage of vasoconstrictive action.

Cytokine profile of human bronchoalveolar macrophages and bronchial epithelial cells in response to inhalation particles of the cyclosporine derivative IMM 125

Administration of antiasthmatic drugs in the form of inhalation particles may alter the cytokine network in the airways, independently of their pharmacological actions. Changes induced by drugs not well tolerated may potentially contribute to the immunopathology of the disease, a strongly undesirable effect. In this study, cell viability assays and characterization of the cellular profile of cytokines and chemokines were performed in order to investigate the response of human bronchoalveolar macrophages and bronchial epithelial cells in culture to inhalation particles of the cyclosporine derivative IMM 125. Interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNFalpha), and IL-8 were assayed by enzyme-linked immunosorbent assay (ELISA) in the supernatants of bronchoalveolar macrophages, and RANTES, granulocyte--macrophage colony-stimulating factor (GM-CSF), and IL-8 in those of bronchial epithelial cells. Cells were studied both under basal and stimulated conditions (lipopolysaccharide and TNFalpha were used for activating macrophages and epithelial cells, respectively). The immunosuppressant FK 506 and the glucocorticoid Budesonide served as comparison. IMM 125 did not affect cell viability (except at high concentrations and long time periods). Moreover, IMM 125 did not induce an increase in the secretion of any of the cytokines and chemokines measured with respect to nontreated cells, except for a slight increase in IL-8, an effect that was also observed for FK 506, Budesonide, and inert latex particles, and was therefore regarded as nonspecific. Furthermore, IMM 125 significantly decreased the secretion of TNFalpha, IL-1beta by macrophages, and GM-CSF by epithelial cells, suggesting an antiinflammatory potential. In conclusion, the present in vitro results point to a good tolerance of human airways to IMM 125 inhalation particles.

Production of a cytotoxic proteoglycan using callus culture of saffron corms (Crocus sativus L.)

Saffron corms have been demonstrated to contain a proteoglycan that inhibits growth of human tumor cells. In this study, we show strong evidence indicating that callus cultures of saffron corm also synthesize such glycoconjugate. This compound is cytotoxic against human cervical epithelioid carcinoma cells (IC50 = 7 mg ml-1), and consists of approximately 90% carbohydrate and 10% protein. In order to optimize the glycoconjugate purification to complete functional and therapeutic studies, we have designed an improved method consisting of anion-exchange chromatography and reversed-phase HPLC, which can be easily scaled-up.

Different efficacy of in vivo herpes simplex virus thymidine kinase gene transduction and ganciclovir treatment on the inhibition of tumor growth of murine and human melanoma cells and rat glioblastoma cells

Initial studies have demonstrated the therapeutic efficacy for cancer treatment of in vivo transfer of the herpes simplex virus thymidine kinase gene followed by ganciclovir (GCV) treatment. However, recent studies have questioned the validity of this approach. Using retroviral vector-producing cells (VPC) as a source for in vivo gene transfer, we evaluated the efficacy of in vivo transduction of malignant cells using three different tumor cell models: B16 murine and IIB-MEL-LES human melanomas and a C6 rat glioblastoma. In vitro studies showed a bystander effect only in C6 cells. In vivo studies showed an inhibition of tumor growth in the two melanoma models when tumor cells were coinjected with VPC-producing retroviral vectors carrying the herpes simplex virus thymidine kinase gene, followed by GCV treatment; however, 100% of mice developed tumors in both models. Under similar experimental conditions, 70% (7 of 10) of syngeneic rats completely rejected stereotactically transferred C6 tumor cells; most of them (5 of 10) showed a prolonged survival. Treating established C6 tumors with VPC-producing retroviral vectors carrying the herpes simplex virus thymidine kinase gene and GCV led to the cure of 33% (4 of 12) of the animals. Rats that rejected tumor growth developed an antitumor immune memory, leading to a rejection of a stereotactic contralateral challenge with parental cells. The immune infiltrate, which showed the presence of T lymphocytes, macrophages, and polymorphonuclear cells at the site of the first injection and mainly T lymphocytes and macrophages at the site of tumor challenge, strengthened the importance of the immune system in achieving complete tumor rejection.

Predictivity of an in vitro model for acute and chronic skin irritation (SkinEthic) applied to the testing of topical vehicles

An in vitro human reconstructed epidermis model (SkinEthic) used for screening acute and chronic skin irritation potential was validated against in vivo data from skin tolerability studies. The irritation potential of sodium lauryl sulfate (SLS), calcipotriol and trans-retinoic acid was investigated. The in vitro epidermis-like model consists of cultures of keratinocytes from human foreskin on a polycarbonate filter. The modulation of cell viability, the release and gene expression of proinflammatory cytokines, interleukins 1alpha and 8, and morphological changes were evaluated during 3 days as endpoints representative for an inflammatory reaction. The cumulative irritation potential of the topical products was evaluated in a human clinical study by visual scoring and biophysical measurement of inflammatory skin reaction after repeated 24 h applications over 3 weeks under Finn chamber patches. All topical products that were nonirritating in the human study were noncytotoxic and did not induce cytokine expression in the in vitro acute model (day 1 exposure). All irritating controls exhibited specific cell viability and cytokine patterns, which were predictive of the in vivo human data. The ranking of mild to moderate skin irritation potential was based on the lack of cytotoxicity and the presence of cytokine patterns including gene expression specific for each irritant, using the chronic in vitro model (up to 3 days exposure). The human reconstructed epidermis model SkinEthic was shown to be a reliable preclinical tool predicting the irritation potential of topical products. Moreover, it is a useful model in a two-step tiered strategy for screening acute and chronic irritation potential for the selection of vehicles for new topical drugs.

The Arabidopsis CBF gene family is composed of three genes encoding AP2 domain-containing proteins whose expression Is regulated by low temperature but not by abscisic acid or dehydration

We have identified two genes from Arabidopsis that show high similarity with CBF1, a gene encoding an AP2 domain-containing transcriptional activator that binds to the low-temperature-responsive element CCGAC and induces the expression of some cold-regulated genes, increasing plant freezing tolerance. These two genes, which we have named CBF2 and CBF3, also encode proteins containing AP2 DNA-binding motifs. Furthermore, like CBF1, CBF2 and CBF3 proteins also include putative nuclear-localization signals and potential acidic activation domains. The CBF2 and CBF3 genes are linked to CBF1, constituting a cluster on the bottom arm of chromosome IV. The high level of similarity among the three CBF genes, their tandem organization, and the fact that they have the same transcriptional orientation all suggest a common origin. CBF1, CBF2, and CBF3 show identical expression patterns, being induced very rapidly by low-temperature treatment. However, in contrast to most of the cold-induced plant genes characterized, they are not responsive to abscisic acid or dehydration. Taken together, all of these data suggest that CBF2 and CBF3 may function as transcriptional activators, controlling the level of low-temperature gene expression and promoting freezing tolerance through an abscisic acid-independent pathway.

Development of the paranasal sinuses in children with sinus disease

In a previous report, the authors defined the normal development of the paranasal sinuses. Landmarks and dimensions relevant to functional endoscopic sinus surgery were measured on the computed-tomography images of 145 children who were free of significant sinusitis. The present study compares those normal values to the same measurements in 235 cases of sinus disease. No significant difference was found between normal and diseased groups in any of the 10 dimensions originally reported or in six derived measures. There appears to be no association between sinus disease and any of these dimensions. The previously reported norms are applicable to cases of pediatric sinus disease.

Mechanisms involved in the somatostatin-induced contraction of vascular smooth muscle cells

In experimental models and in humans, somatostatin (SRIF) is able to contract certain vascular structures. The present experiments were designed to assess the capacity of SRIF to contract cultured rat aortic vascular smooth muscle cells (VSMC), and to analyze the possible mechanisms involved. Cells incubated with SRIF showed a significant reduction in planar cell surface area, in a time- and dose-dependent manner. This effect was partially blocked by preincubating the cells with a combination of calcium antagonists (10 microM verapamil, plus 10 microM 3,4,5-Trimethoxybenzoic acid 3-(diethylanino) octyl ester TMB)-8). SRIF was also able to stimulate myosin light-chain phosphorylation in VSMC. A small but significant increase of intracellular calcium concentration, and decreased levels of cAMP, without changes in cGMP, were detected in VSMC incubated with SRIF. A search for the known SRIF receptors present in these cells, by reverse transcription-polymerase chain reaction, only SRIF receptor-4 was found to be present. These results demonstrate the ability of SRIF to contract cultured rat VSMC. The contraction observed in these cells appears to be due to a mixed mechanism, that involves [Ca2+]i and cAMP as second messengers, and is likely mediated via SRIF receptor-4.

[Antitumor gene therapy using suicide genes]

Tumor cells transduced with retrovirus carrying the herpes simplex-1 virus thymidine kinase (HSV-tk) are capable of transforming the antiviral drug ganciclovir (GVC) into a metabolic form only toxic to dividing cells. The efficiency of this suicide gene therapy is increased by a "bystander" effect resulting not only in the death of the recipient cell, but also in the death of non modified surrounding cells. Even though the mechanism of this "bystander" effect remains to be elucidated, strong evidence suggest that the immune system plays a main role to achieve complete tumor eradication. In the present study we evaluate the efficiency of this suicide system on three different tumor models: one human melanoma, one murine melanoma, and a rat glioblastoma. Tumors were established by injection of tumor cells s.c. in nude and C57Bl/6 mice, respectively, and stereotactically into the brain of Sprague Dawley rats. Animals in the treated group were co-injected with packaging cells producing recombinant retrovirus carrying the HSV-tk gene, and followed by i.p. administration of GVC. In short term studies, we observed inhibition of tumor growth for all the tumor models evaluated (p < 0.01). In long term studies, using the C6 rat glioma line, 50% of the animals survived longer than 75 days (p < 0.0001), and were able to reject a contralateral challenges with C6 parental cells. Histological and immunohistochemical analysis showed the presence at an inflammatory infiltrate composed by T lymphocytes, macrophages and polymorphonuclear cells. These data demonstrate that suicide genes might represent an attractive form of cancer gene therapy in the treatment of brain tumors and their intracerebral dissemination.

14-3-3 proteins are part of an abscisic acid-VIVIPAROUS1 (VP1) response complex in the Em promoter and interact with VP1 and EmBP1

Protein-DNA complexes were formed when nuclear extracts from embryogenic rice suspension cultures or maize embryos were incubated with an abscisic acid-VIVIPAROUS1 (VP1) response element (Em1a) from the Em promoter. Monoclonal antibodies generated to GF14, a 14-3-3 protein from plants, resulted in gel retardation of the Em1a-protein complexes. Antibodies generated to the C and N termini of GF14 detected protein isoforms in rice nuclear and cytoplasmic extracts, but no differences in distribution of the GF14 isoforms were recognized between the nucleus and cytoplasm or when abscisic acid-treated and untreated tissues were compared. When recombinant GF14 fusion proteins from rice were added to nuclear extracts, novel complexes were formed that required the dimerization domain of GF14. Chemical cross-linking showed that GF-14 interacted with the basic leucine zipper factor EmBP1, which binds specifically to Em1a, and with VP1, which transactivates Em through Em1a. GF14 proteins from rice were shown to interact with VP1 in yeast through the dimerization domain of GF14. Our results indicated that GF14 interacts with both site-specific DNA binding proteins (i.e., EmBP1) and tissue-specific regulatory factors (i.e., VP1) and may provide a structural link between VP1 and the Em1a transcriptional complex.

[The value of cardiac troponin I as diagnostic test in the study of chest pain]

BACKGROUND AND OBJECTIVES

Cardiac troponin I is a highly sensitive and specific myocardial injury marker. We have analyzed the use of cardiac troponin I values in the diagnosis of coronary artery disease, in previously healthy patients who developed chest pain with inconclusive analytical and ECG diagnostic findings.

PATIENTS, MATERIAL AND METHODS

A one year cross-sectional consecutive study was conducted, in a total of 37 patients with no previously known heart disease who were admitted to the coronary unit for suspected anginal chest pain with normal cardiac enzymes and ECG. Abnormal cardiac troponin I levels at admission were defined as > or = 0.4 ng/ml, and were compared with coronary angiography or exercise test results and related to the duration of pain and the time from the appearance of symptoms to blood extraction.

RESULTS

Thirty-three of the 37 initially included patients were studied. Coronary artery disease was diagnosed in 22, 15 of whom had increased troponin I values, yielding a sensitivity of 68% (48%-84%) and a specificity of 82% (53%-97%). In the subgroup of patients with pain lasting > 30 min, sensitivity reached 85% (59%-97%) and specificity 83% (42%-99%). There were no significant differences between subgroups with different time delays from appearance of symptoms to blood extraction.

CONCLUSIONS

Cardiac troponin I is very useful for the studying ischemic chest pain without a definitive diagnostic ECG nor biochemical data, resulting in a high sensitivity and specificity for myocardial ischemic injury detection. Its diagnostic value increases in cases of prolonged pain episodes.

Similarity and the development of rules

Similarity-based and rule-based accounts of cognition are often portrayed as opposing accounts. In this paper we suggest that in learning and development, the process of comparison can act as a bridge between similarity-based and rule-based processing. We suggest that comparison involves a process of structural alignment and mapping between two representations. This kind of structure-sensitive comparison process--which may be triggered either by experiential or symbolic juxtapositions--has a twofold significance for cognitive development. First, as a learning mechanism, comparison facilitates the grasp of structural commonalities and the abstraction of rules; and, second, as a mechanism for the application and extension of previously acquired knowledge, comparison processes facilitate the application of abstract knowledge to new instances.

Cyclosporine A-induced contraction of isolated rat aortic smooth muscle cells

The mechanisms by which the immunosuppressive drug cyclosporine A (CsA) induces hypertension and nephrotoxicity are still not fully understood. Although smooth muscle cell (SMC) contraction is probably the mechanism of vasoconstriction, the direct contractive effect of CsA on SMCs has not yet been demonstrated. Thus, it was the purpose of this study to evaluate the direct effects of CsA in cultured SMCs through interactive image analysis. In aortic SMCs, CsA at the concentrations of 0.01, 0.1 and 1 microM, caused a concentration-dependent decrease of the planar cross-sectional area (PCSA) after 30 min and 60 min of treatment. The PCSA decreases were statistically significantly different from control at all concentrations. No cytotoxicity was observed under these conditions. Ten minutes preincubation of SMCs with a monoclonal antibody against endothelin-1 (ET-1) significantly prevented the CsA effects at 1 microM. When the same antibody was heat inactivated or an unspecific antibody (anti-desmin immunoglobulin G) was applied, the CsA-induced contractions were not affected. These data suggest that CsA can cause a direct contractive effect on vascular SMCs. This effect is partly mediated by ET-1.

Development of the paranasal sinuses in children

The development of computed tomography and functional endoscopic sinus surgery has improved diagnosis and management of sinusitis. It has also renewed interest in the developmental anatomy of the paranasal sinuses. There are significant differences between adult and pediatric sinus anatomy, and to safely perform functional endoscopic sinus surgery in children, the surgeon must be aware of these differences. To define the developmental anatomy of the paranasal sinuses, we analyzed 145 computed tomograms from patients under 18 years of age. The study emphasized landmarks at the level of the maxillary sinus ostium. In addition, distances and angles from the nasal spine to various points in the sinuses were determined. The structures were identified and traced on a digitizing tablet. Means and standard deviations were calculated for each measure as a function of age. This study can aid a better understanding of sinus development in children and provide guidance to the endoscopic sinus surgeon.

Effects of prenatal diazepam on two-way avoidance behavior, swimming navigation and brain levels of benzodiazepine-like molecules in male Roman high- and low-avoidance rats

Utilizing psychogenetically selected Roman high- and low-avoidance rats (RHA/Verh and RLA/Verh), the present experiments investigated the effects of prenatally administered vehicle and diazepam (1 and 3 mg/kg per day, SC) on the behavior and neurochemistry of adult, male offspring. Active, two-way avoidance behavior was analyzed in 96 rats, at 6 months of age, and swimming navigation in 68 others, at 11 months. Three weeks after testing, selected brain areas from the latter animals were immunoassayed for benzodiazepine (BZD)-like molecules. The 3 mg/kg dose of diazepam both decreased freezing behavior in the shuttle box and reduced the hippocampal content of BZD-like molecules in the RLA/Verh male rats. Swimming navigation (spatial learning), at which the RLA/Verh rats were more adept, was not specifically affected by prenatal diazepam in either rat line. The possibility exists that an increased hippocampal release of BZD-like substances may be necessary to alter shuttle box behavior in RLA/Verh rats.

Effects of somatostatin on cultured human mesangial cells

The present experiments were devoted to analyzing the hypothesis that somatostatin (SS) could modulate glomerular filtration rate by interacting with mesangial cells. Studies were performed in cultured human mesangial cells, passages 3-5. Radioligand experiments demonstrated the presence in the cells of two kinds of receptors, with high (dissociation constant 14 pM. Number of sites: 426 fmol/mg) and low (dissociation constant 56 pM. Number of sites: 20, 111 fmol/mg) affinity. SS prevented in a dose-dependent manner the reduction in planar cell surface area induced by 100 nM Angiotensin II (AII). This effect was not inhibited by the blockade of the vasorelaxing prostaglandins (indomethacin, 10 microM), nitric oxide (L-N-methyl-arginine, 0.2 mM), adenylate cyclase (2,5'-dideoxyadenosine, 0.1 mM), or guanylate cyclase (Methylene blue, 30 microM; LY-83583, 10 microM), but it was potentiated by zaprinast, an inhibitor of the cyclic GMP (cGMP)-specific phosphodiesterase. SS also blocked the increase in myosin light chain phosphorylation induced by AII. SS increased cGMP synthesis by cultured human mesangial cells, an effect that seemed to be dependent on the stimulation of a particulate guanylate cyclase. Preincubation of the cells with pertussis toxin (0.5 microgram/ml) inhibited the effect of SS on the AII-dependent changes in planar cell surface area, as well as the SS-dependent cGMP stimulation. In summary, these results demonstrate the ability of SS to relax cultured human mesangial cells, thus supporting a role for this peptide in the regulation of the glomerular filtration rate. The SS-dependent mesangial cell relaxation may be due to changes in the intracellular concentrations of cGMP, as a consequence of the activation of a particulate guanylate cyclase.

Acute otitis media in childhood: a study of 20,532 cases

We present a study of acute otitis media among 20,532 Spanish children during a 6-month period from January through June 1991. The study was done by distributing a questionnaire to all Spanish pediatricians. Of the patients 51.7% were girls and 48.3% boys; 68.7% of all children were younger than 5 years. The most frequent symptoms were otalgia or irritability, 92.7%; fever, 63.5%; otorrhea, 24.9%; vomiting, 21.4%; and another concomitant upper respiratory tract infection, 65.5%. Otitis was bilateral in 45.6% of the cases. The most frequently used antibiotic was cefixime (38%), followed by amoxicillin-clavulanate (22.2%), amoxicillin (15.3%), 2nd-generation cephalosporins (13.5%) and macrolides (8.8%). In 11.8% of the patients, a change in the initial antibiotic therapy was required due to adverse effects. Resolution of symptoms occurred in 77.8% of the patients.

[Hereditary spherocytosis: clinical characteristics and treatment with splenectomy]

PURPOSE

To analyse the clinico-biological characteristics at diagnosis, the clinical course, and the response to splenectomy of a series of patients with hereditary spherocytosis (HS).

PATIENTS AND METHODS

The clinical records of 61 patients diagnosed of HS along 30 years were reviewed. The diagnosis was based upon the existence of family history, physical findings, blood cell examination, reticulocyte count, peripheral blood spherocytes, red-cell osmotic fragility, auto-haemolysis, serum haptoglobin, LDH, non-conjugated bilirubin and direct anti-human globulin test. Data regarding the time of diagnosis and clinical course were taken into account in every case. Within the sub-group of 29 patients undergoing splenectomy, the changes in haemoglobin rates and reticulocyte and platelet counts after surgery were evaluated.

RESULTS

Of the 61 patients, 35 were men and 26 women; the median age at diagnosis was 13 years (range: 0-64 years). Family history was positive in only 40% of the cases. The mean haemoglobin rate was 112 g/L (range: 46-151 g/L), over 60% of the patients having anaemia. The mean reticulocyte count was 282 x 10(9)/L (range: 31-583 x 10(9)/L), this being above 100 x 10(9)/L in 91% of the cases. Red-cell osmotic fragility with fresh blood was increased in 86% of the cases, and in 97% after blood incubation. Serum haptoglobins were decreased, whereas LDH was increased in 58% of the patients and non-conjugated bilirubin in 72%. Splenomegaly appeared in the clinical course in 87% of the patients; cholelithiasis was present in 31.5% of them. Haemoiytic crises were seen in 45% of patients, aplastic phases in 7%, and transfusion was needed by 16% of the patients to variable extents. Splenectomy was performed in 50% of the instances before 14 years of age (range: 4-64 years), and it increased haemoglobin rates in 40 g/L, anaemia being corrected in all cases; the mean reticulocyte count returned to normal, but thrombocytosis developed after surgery, it being present in 82% of the cases 2-3 months later.

CONCLUSIONS

(1) Wide clinical variability is seen in HS, from severe forms requiring frequent transfusion to asymptomatic cases. (2) Highly frequent findings in HS are reticulocytosis and splenomegaly; relatively frequent were anaemia, haemolytic crisis and cholelithiasis, in this order. (3) Anaemia was always corrected after splenectomy, which also rose the haemoglobin rate even in the cases without anaemia, and returned the reticulocyte count to normal values.

Recovery of central noradrenergic neurons one year after the administration of the neurotoxin DSP4

The long-term effects of the systemic administration of DSP4 (N-(2-chloroethyl)N-ethyl-2-bromobenzylamine hydrochloride), a selective noradrenergic neurotoxin, on the endogenous levels of monoamines and their metabolites and on alpha- and beta-adrenoceptors in selected brain regions of the rat were examined. After 7 days, DSP4 caused a marked reduction (about 80%) of endogenous noradrenaline levels in locus coeruleus-innervated regions. At 90, 240 and 300 days after DSP4 injection, a partial and gradual recovery (50%, 41% and 25% of control values, respectively) of the noradrenaline cortical levels was evident. One year after DSP4 administration, brain regional noradrenaline stores were almost completely recovered. No changes in 5-hydroxytryptamine levels were observed in the three time intervals, but a mild decrease in cortical and hippocampal 5-hydroxyindolacetic acid levels was found 7 days after DSP4 injection. Following the profound noradrenaline depletion seen at 7 days, the cerebral cortical density of alpha 1-, alpha 2- and beta-adrenoceptors was significantly increased. Assessment of adrenergic receptors in cerebral cortex at 365 days after DSP4 injection, indicated that alpha 1- and alpha 2-adrenoceptor densities did not differ from control values; however, the density of beta-adrenoceptors remained increased. No changes were observed in the affinities of the three types of adrenoceptors studied. These results indicate that after a selective noradrenergic denervation induced by DSP4, there is a slow and gradual recovery of noradrenaline stores and of alpha 1- and alpha 2-adrenoceptor populations, suggesting a possible regrowth and/or collateral sprouting of noradrenergic terminals.

[Nuclear magnetic resonance and anesthesia]

Anesthesia for imaging by nuclear magnetic resonance presents special problems due to the effect of the large magnetic field and high frequency radio waves on monitoring and respiratory systems. These systems in turn affect image quality. Special materials should be designed specifically for this context or existing materials should be modified.

Sexual differences in the effect of the GABAergic system on LH secretion and in the hypothalamic ontogenesis of GABAA receptors in prepubertal rats

The administration of aminooxyacetic acid (AOAA), which increases hypothalamic GABA concentrations, induced a significant increase in LH levels in female rats of 12, 16 and 18 days of age. This stimulatory effect of AOAA on serum LH levels was not observed at 21 and 25 days of age whereas a significant decrease in the LH concentrations by AOAA was found at 30 days of age. The neonatal androgenization of female rats abolished the effects of AOAA and no effects of AOAA were found in male rats at the different ages studied. The muscimol binding sites in medial basal and preoptic anterior hypothalamic areas showed a significant different sexual ontogenic pattern. Males rats castrated at birth showed a very similar ontogenic pattern of [3H]muscimol binding sites to female rats and significantly different to male control rats. It is concluded that there are sexual differences in the effect of GABAergic system on LHRH-LH secretion and in the development of hypothalamic GABAA receptors during sexual maturation. These differences are probably connected with the neonatal exposure to androgens that would induced changes in the composition and probably in the properties of GABAA receptor that in turn modified its effects on LHRH neurons.

[Lyme disease in the province of Soria: clinico-epidemiologic study]

BACKGROUND

To determine the prevalence of the Borrelia burgdorferi infection in the Soria Province, and the detection of the human disease cases.

METHODS

By an indirect immunofluorescence technique, we had studied total antibodies (IgG, IgM and IgA) against B. burgdorferi (B 31 strain) in the sera of 298 people (150 men y 148 women) of the Soria Province. The results were considered positive when the titers were same or upper to 1/256. All positive sera were tested for specific IgM antibodies by same method; IgM results were considered positive when the titers were upper to 1/16.

RESULTS

13.1% of the people had positive results (39 sera): 14 for women (9.5%) and 25 for men (16.7%). We detected 14 sera with positive IgM. We demonstrated titers same or upper to 1/256 in all age group, with a major prevalence in the age group between 41 and 50 years (22.6%). In all areas of the Province we detected positive results and in many of this areas the positivity was upper to 30% of the studied sera. 12 persons with positive IgM or high titers of total antibodies presented signs or symptoms of disease in relation with B. burgdorferi infection; 6 persons had alterations of the liver function do not explicable by other etiology.

CONCLUSIONS

The B. burgdorferi infection present a high prevalence in this Province and a wide geographic distribution, with high endemic areas. We demonstrated patients with symptomatology compatible with Lyme borreliosis, and we wish to emphasize the frequency of alterations of the liver function in this group of people.

Cloning of cDNA, expression, and chromosomal location of genes encoding the three types of subunits of the barley tetrameric inhibitor of insect alpha-amylase

Three cDNA clones from barley developing endosperm, corresponding to proteins BTAI-CMa, BTAI-CMb and BTAI-CMd, which are the three types of subunits of the tetrameric inhibitor of insect alpha-amylases, have been identified and sequenced. The deduced amino acid sequence of BTAI-CMb corresponds to the CM16/CM17 type of subunit in wheat (92/90% identical residues) and has one putative N-glycosylation site (NLT) and a possible kinase-C phosphorylation site (SCR). The BTAI-CMa sequence differs at four amino acid residues from a previously reported one from cv. Bomi and the sequence deduced for BTAI-CMd completes (11 N-terminal residues) and confirms previously available data. The gene for BTAI-CMa (Iat1) is located in the beta arm of barley chromosome 7H (syn.1), while genes for both BTAI-CMb (Iat2) and BTAI-CMd (Iat3) are in the long arm of chromosome 4H. The three genes are expressed in endosperm and their mRNAs are not detected in the other tissues tested, except Iat1, which seems to be expressed at a low level in coleoptile and roots, where it is switched off by 50 microM methyl jasmonate.

Tumor necrosis factor-induced contraction of cultured rat mesangial cells: interaction with angiotensin II

The role of tumor necrosis factor alpha in the regulation of renal function, particularly glomerular filtration rate, has not been completely defined. This study was designed to assess the intrinsic role of this cytokine on glomerular filtration rate by analyzing its short-term effect on the degree of contraction in cultured rat mesangial cells, not only directly but also in the presence of angiotensin II. Contraction was evaluated both morphologically--by measuring planar cell surface area of cultured rat mesangial cells and glomerular cross-sectional area of isolated rat glomeruli--and biochemically--by analyzing myosin light-chain phosphorylation in cells. Tumor necrosis factor alpha significantly decreased planar cell surface area in a dose-dependent and time-dependent manner, an effect completely abolished by preincubation of the cells with platelet-activating factor receptor antagonists BN 52021 and alprazolam. This effect was also observed in the presence of angiotensin II, whether tumor necrosis factor alpha was added before or after angiotensin II, increasing the reduction in planar cell surface area induced by angiotensin II in both cases. Changes in planar cell surface area were evident not only when the absolute values of this parameter were considered but also when the percentage of contracted cells (cells with a planar cell surface area reduction > 10%) was analyzed. Tumor necrosis factor alpha also induced a significant reduction of glomerular cross-sectional area in isolated rat glomeruli. The results of the morphologic studies were supported by myosin light-chain phosphorylation experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential cholinergic and non-cholinergic actions of acetylcholinesterase in the substantia nigra revealed by fasciculin-induced inhibition

The effects of the peptide fasciculin (FAS), a potent inhibitor of acetylcholinesterase (AChE) have been examined, following unilateral microinfusion, on tissue levels of monoamines in the rat substantia nigra and concomitant circling behaviour. Although FAS inhibited 87% of total AChE, the levels of dopamine and its metabolites remained unchanged. Furthermore, the treatment induced modest contraversive rotation which was markedly enhanced in the presence of a systemic challenge with apomorphine. This behavioural effect of FAS was partially reversed by systemically administered atropine. Any possible interaction of FAS with nigral dopamine systems was further investigated by testing the peptide in animals that five days earlier had undergone a 6-hydroxydopamine (6-OHDA) lesion of the SN such that dopamine and AChE were significantly but not completely reduced. In a majority of these animals, FAS treatment caused a reversal of the lesion induced ipsiversive rotation, ie restored contraversive rotation. It is concluded that in the SN, FAS can have biochemical and behavioural actions independent of local dopamine systems and linked to cholinergic transmission. In addition, treatment with FAS in the substantia nigra also reveals the possible existence of at least two distinct pools of AChE with, respectively, non-cholinergic and cholinergic actions.