Glycosaminoglycan origin and structure revealed by multivariate analysis of NMR and CD spectra

Principal component analysis (PCA) is a method of simplifying complex datasets to generate a lower number of parameters, while retaining the essential differences and allowing objective comparison of large numbers of datasets. Glycosaminoglycans (GAGs) are a class of linear sulfated carbohydrates with diverse sequences and consequent complex conformation and structure. Here, PCA is applied to three problems in GAG research: (i) distinguishing origins of heparin preparations, (ii) structural analysis of heparin derivatives, and (iii) classification of chondroitin sulfates (CS). The results revealed the following. (i) PCA of heparin (13)C NMR spectra allowed their origins to be distinguished and structural differences were identified. (ii) Analysis of the information-rich (1)H and (13)C NMR spectra of a series of systematically modified heparin derivatives uncovered underlying properties. These included the presence of interactions between residues, providing evidence that a degree of degeneracy exists in linkage geometry and that a different degree of variability exists for the two types of glycosidic linkage. The relative sensitivity of each position (C or H nucleus) in the disaccharide repeating unit to changes in O-, N-sulfation and N-acetylation was also revealed. (iii) Analysis of the (1)H NMR and CD spectra of a series of CS samples from different origins allowed their structural classification and highlighted the power of employing complementary spectroscopic methods in concert with PCA.

Studying soil organic matter using 13C CP-MAS NMR: the effect of soil chemical pre-treatments on spectra quality and representativity

(13)C CP-MAS NMR spectroscopy is a technique that has proved to be useful in studying soil organic matter (SOM). Nevertheless, NMR spectra exhibit a weak signal and have very low resolution due to: the low natural abundance of (13)C (1.1% of C) in SOM, the generally low SOM content of soils, and the presence of paramagnetic impurities. This paper studies the effects of soil chemical pre-treatments on (13)CP-MAS NMR spectra quality and spectra representativity i.e. soil C mass balance. After chemical pre-treatment to increase total organic carbon (TOC) content and C/Fe ratio, eight soils characterized by different levels of organic carbon content and C/Fe ratios were studied using (13)CP-MAS NMR. Moreover, where chemical treatments were not applicable due to high carbon losses, the number of (13)CP-MAS NMR scans was increased in order to obtain satisfactory spectra. Results show that chemical pre-treatment of soils with C/Fe>1 caused high C losses. Bulk soils were therefore studied by increasing the number of (13)CP-MAS NMR scans. Acceptable spectra were obtained from 8K scans (1K=1024 transient). On the other hand, even when a large number of scan (32K) are used, soil with C/Fe<1 cannot be studied. As these soils are characterized by low C losses after HCl treatments (range of 2.9-25.4%), a pre-treatment of at least 1.39 mol l(-1) HCl removes excess Fe and at the same time increases C/Fe ratio resulting in 32K scans providing good spectra.

Site-specific interactions of copper(II) ions with heparin revealed with complementary (SRCD, NMR, FTIR and EPR) spectroscopic techniques

The interactions between Cu(II) ions and heparin were investigated using several complementary spectroscopic techniques. NMR indicated an initial binding phase involving specific coordination to four points in the structure that recur in slightly different environments throughout the heparin chain; the carboxylic acid group and the ring oxygen of iduronate-2-O-sulfate, the glycosidic oxygen between this residue and the adjacent (towards the reducing end) glucosamine and the 6-O-sulfate group. In contrast, the later binding phase showed little structural specificity. One- and two-dimensional correlated FTIR revealed that complex out of phase (asynchronous) conformational changes also occurred during the titration of Cu(II) ions into heparin, involving the CO and N-H stretches. EPR demonstrated that the environments of the Cu(II) ions in the initial binding phase were tetragonal (with slightly varied geometry), while the later non-specific phases exhibited conventional coordination. Visible spectroscopy confirmed a shift of the absorbance maximum. Titration of Cu(II) ions into a solution of heparin indicated (both by analysis of FTIR and EPR spectra) that the initial binding phase was complete by 15-20 Cu(II) ions per chain; thereafter the ions bound in the non-specific mode. Hetero-correlation spectroscopy (FTIR-CD) improved resolution and assisted assignment of the broad CD features from the FTIR spectra and indicated both in-phase and more complex out of phase (synchronous and asynchronous, respectively) changes in interactions within the heparin molecule during the titration of Cu(II) ions.

Influence of substitution pattern and cation binding on conformation and activity in heparin derivatives

As model compounds for the biologically important heparan sulfate, eight systematically modified heparin derivatives were studied by synchrotron radiation circular dichroism (SRCD), which is sensitive to uronic acid conformation. Substitution pattern altered uronic acid conformation, even when structural changes were made in adjacent glucosamine residues (e.g. 6-O-desulfation) and did not involve a chromophore. SRCD spectra of these derivatives following conversion to the Na+, K+, Mg2+, Ca2+, Mn2+, Cu2+ and Fe3+ cation forms revealed that almost all substitution/cation combinations resulted in unique spectra, showing that each was structurally distinct. The detailed effects that binding Na+, K+, Mg2+ and Ca2+ ions had on a 2-de-O-sulfated derivative was also studied by NMR, revealing that subtle changes in conformation (by NOE) and flexibility (by T2 measurements) resulted. Conversion to the K+ and Cu2+ ion forms also drastically modified biological activity, from inactive to active, in a cell-based assay of fibroblast growth factor-receptor (FGF2/FGFR1c) signalling and this effect was not reproduced by free cations. These observations could explain the often-contradictory data concerning structure-activity relationships for these derivatives in the literature and, furthermore, argue strongly against the established trend of considering sequence as a complete structural definition. It also provides additional means of modifying the activity of these polysaccharides and suggests a possible additional level of control in biological systems. There are also obvious potential applications for these findings in the biotechnology sphere.

Linear matrix inequalities approach to reconstruction of biological networks

The general problem of reconstructing a biological interaction network from temporal evolution data is tackled via an approach based on dynamical linear systems identification theory. A novel algorithm, based on linear matrix inequalities, is devised to infer the interaction network. This approach allows to directly taking into account, within the optimisation procedure, the a priori available knowledge of the biological system. The effectiveness of the proposed algorithm is statistically validated, by means of numerical tests, demonstrating how the a priori knowledge positively affects the reconstruction performance. A further validation is performed through an in silico biological experiment, exploiting the well-assessed cell-cycle model of fission yeast developed by Novak and Tyson.

Identification of quadratic nonlinear models oriented to genetic network analysis

The goal of this paper is to provide a novel procedure for the identification of nonlinear models which exhibit a quadratic dependence on the state variables. These models turn out to be very useful for the description of a large class of biochemical processes with particular reference to the genetic networks regulating the cell cycle. The proposed approach is validated through extensive computer simulations on randomly generated systems.

The p85 regulatory subunit of PI3K mediates TSH-cAMP-PKA growth and survival signals

Phosphatidylinositol 3-kinase (PI3K) is necessary for thyroid stimulating hormone (TSH)-induced cell cycle progression. To determine the molecular mechanism linking PI3K to TSH, we have identified a serine residue in p85alpha(PI3K) phosphorylated by protein kinase A (PKA) in vitro and in vivo. Expression of an alanine mutant (p85A) abolished cyclic AMP/TSH-induced cell cycle progression and was lethal in thyroid cells (FRTL-5). The aspartic version of the p85alpha(PI3K) (p85D) inhibited apoptosis following TSH withdrawal. The p85alpha(PI3K) wild type not the p85A bound PKA regulatory subunit RIIbeta in cells stimulated with cAMP or TSH. The binding of the aspartic version of p85alpha(PI3K) to RIIbeta was independent of cAMP or TSH stimulation. Similarly, binding of PI3K to p21Ras and activation of AKT, a downstream PI3K target, were severely impaired in cells expressing the p85A mutant. Finally, we found that the catalytic activity of PI3K was stimulated by TSH in cells expressing the wild-type p85alpha(PI3K) but not in cells expressing p85A. This latter mutant did not affect the epidermal growth factor-stimulated PI3K activity. We suggest that (1) TSH-cAMP-induced PKA phosphorylates p85alpha(PI3K) at serine 83, (2) phosphorylated p85alpha(PI3K) binds RIIbeta-PKA and targets PKAII to the membrane, and (3) PI3K activity and p21Ras binding to PI3K increase and activate PI3K downstream targets. This pathway is essential for the transmission of TSH-cAMP growth signals.

p85 regulatory subunit of PI3K mediates cAMP-PKA and estrogens biological effects on growth and survival

Cyclic adenosine 3'5' monophosphate (cAMP) and protein kinase A (PKA) cooperate with phosphatidylinositol 3' kinase (PI3K) signals in the control of growth and survival. To determine the molecular mechanism(s) involved, we identified and mutagenized a specific serine (residue 83) in p85alpha(PI3K), which is phosphorylated in vivo and in vitro by PKA. Expression of p85alpha(PI3K) mutants (alanine or aspartic substitutions) significantly altered the biological responses of the cells to cAMP. cAMP protection from anoikis was reduced in cells expressing the alanine version p85alpha(PI3K). These cells did not arrest in G1 in the presence of cAMP, whereas cells expressing the aspartic mutant p85D accumulated in G1 even in the absence of cAMP. S phase was still efficiently inhibited by cAMP in cells expressing both mutants. The binding of PI3K to Ras p21 was greatly reduced in cells expressing p85A in the presence or absence of cAMP. Conversely, expression of the aspartic mutant stimulated robustly the binding of PI3K to p21 Ras in the presence of cAMP. Mutation in the Ser 83 inhibited cAMP, but not PDGF stimulation of PI3K. Conversely, the p85D aspartic mutant amplified cAMP stimulation of PI3K activity. Phosphorylation of Ser 83 by cAMP-PKA in p85alpha(PI3K) was also necessary for estrogen signaling as expression of p85A or p85D mutants inhibited or amplified, respectively, the binding of estrogen receptor to p85alpha and AKT phosphorylation induced by estrogens. The data presented indicate that: (1) phosphorylation of Ser 83 in p85alpha(PI3K) is critical for cAMP-PKA induced G1 arrest and survival in mouse 3T3 fibroblasts; (2) this site is necessary for amplification of estrogen signals by cAMP-PKA and related receptors. Finally, these data suggest a general mechanism of PI3K regulation by cAMP, operating in various cell types and under different conditions.

Impact of children's respiratory allergies on caregivers

BACKGROUND

Despite the great attention that has been paid to HRQoL in children with respiratory allergy, few studies have addressed this aspect in relation to caregivers. The aim of our study was to evaluate the impact of childhood respiratory allergies on caregivers by means of a new method.

METHODS

119 parents of children suffering from allergies (75 suffering from asthma and 44 suffering from rhinitis) were recruited from three Italian Allergy Units. Parents were asked to complete the Disease Impact On Caregiver (DIOC), a new non disease specific questionnaire, validated on the Italian population. The questionnaire consists of 31 items grouped in four factors (Performance, Personal gratification, Psychophysical endurance, Socio-emotional domain) and covers the life aspects that could be affected by the assistance duties towards an ill family member.

RESULTS

Child's asthma resulted to have a worse impact on many aspects of a parents' life than rhinitis. Differences resulted to be statistically significant in 19 aspects out of the 31 assessed. The worse impact of asthma versus rhinitis was confirmed in the following domains: Performance (24.0 +/- 18.2 vs 11.5 +/- 17.8), Personal gratification (26.3 +/- 20.5 vs 12.1 +/- 16.5) and Psychophysical endurance (35.0 +/- 24.8 vs 18.8 +/- 21.7). In the Socio-emotional domain no difference emerged.

CONCLUSIONS

Compared to parents of rhinitics, parents of asthmatic children appear to be more compromised in their resistance to stress, mood, emotional stability, amount of spare time and leisure activities. Our results suggest the need of giving the due attention to these problems both in clinical practice and in research, in order to avoid possible interferences of the caregiver's distress in the optimization of treatment outcome.

Polysaccharides from the fruit bodies of the basidiomycete Laetiporus sulphureus (Bull.: Fr.) Murr

The two main polysaccharides from the basidiomycetous fungus Laetiporus sulphureus were isolated, purified and characterized. The structural assignments were carried out using (13)C, (1)H, and (1)H,(13) HSQC nuclear magnetic resonance spectroscopy, methylation analysis, and Smith degradation. One was a linear beta-glucan having a (1-->3)-linked main chain, namely laminaran. The other was a fucomannogalactan, which consisted of a main chain of (1-->6)-linked alpha-D-galactopyranosyl residues, a part of them being substituted at O-2 by 3-O-D-mannopyranosyl-L-fucopyranosyl, alpha-D-mannopyranosyl and in a minor proportion, alpha-L-fucopyranosyl groups. This heteropolysaccharide is related to those of other Basidiomycetes heterogalactans, although it differs distinctly in its side-chain structures. Whereas part of the single-unit L-fucopyranosyl and/or 3-O-alpha-mannopyranosyl-L-fucopyranosyl residues are present as side chains of the other heterogalactans, additional alpha-D-mannopyranosyl units are present in our fucomannogalactan of L. sulphureus.

Intraabdominal abscess following open and laparoscopic appendectomy in the pediatric population

BACKGROUND

Studies comparing intraabdominal abscess (IAA) rates following laparoscopic appendectomy (LA) and open appendectomy (OA) have shown conflicting results.

METHODS

The charts of 324 children undergoing appendectomy were reviewed retrospectively to examine the incidence of IAA.

RESULTS

Of the 324 appendectomies, 204 (63.0%) were completed laparoscopically and 119 (36.7%) were performed open. The conversion rate was 0.2% (1/324). Of the 15 (4.6%) IAAs, 7 occurred in the LA group (3.4%) and 8 occurred in the OA group (6.7%) [p = not significant (NS)]. The incidence of IAA for perforated appendicitis for LA was 15% (7/46) and that for OA was 10% (7/70) (p = NS).

CONCLUSION

This study demonstrates no statistically significant difference in the rate of IAA among children following LA and OA. LA can be performed for perforated appendicitis without increasing the risk of IAA.

Sensitization to food or inhalant allergens in pediatric patients. Clinical usefulness of first-level panel tests for specific IgE

First-level in vitro diagnostic tests for specific IgE against common inhalant or food allergens have been used to identify allergic patients. We evaluated the performance of Phadiatop and Fx5 (mixed food allergens) serological tests (Pharmacia Diagnostics AB, Uppsala, Sweden) in different groups of pediatric patients. We studied two groups of pediatric patients: 61 children recruited from an Allergy and Clinical Immunology Unit (Group 1); 136 children from a Pediatric Unit not specifically devoted to allergic diseases (Group 2); the two groups comprised patients with (A) or without (B) clinical suspicion of allergic disease. Sera were collected from routine blood analysis. Frequencies of positivities for Phadiatop and/or Fx5 were very high (68.8%) in Group 1, however, as many as 35.5% of Group 2 children were positive, as well. All the patients of Group 1 with clinical suspicion of allergic disease (1A), confirmed by allergologic diagnostic tests, had a positive first-level test; 42.8% only of the patients in Group 2 with suspicion of allergic disease (2A) had a positive first-level test. None of the Phadiatop/Fx5-negative children of Group 2A had specific-IgE with conventional tests. In 30% of children not suspected for allergic diseases (1B and 2B), positive first-level tests were observed. Such unexpected positivities were confirmed by single specific-IgE assays in 94.7% (for inhalants) or 71% (for foods) of cases. In conclusion, altogether the sensitivity and overall performance of first-level tests in pediatric populations (especially for inhalant allergens) may suggest their use, under appropriate circumstances, both as a first diagnostic approach (to rule out negative patients) and for screening purposes.

Cytokine pattern in allergic and non-allergic chronic rhinosinusitis in asthmatic children

BACKGROUND

Rhinosinusitis represents one of the most common chronic diseases. The association of rhinosinusitis with asthma has been frequently reported. Eosinophils and Th2 cells play a pathogenic mechanism in asthma.

OBJECTIVE

The aims of the study were to evaluate the cytokine pattern in chronic rhinosinusitis in asthmatic children and to compare the findings in allergic vs. non-allergic asthmatics.

METHODS

Thirty-five asthmatic children were evaluated, 19 males and 16 females, with an average age of 8.7 years. All children were asthmatic and suffered from chronic rhinosinusitis. Twenty were allergic and 15 were non-allergic. Ten healthy children were studied as normal controls. Evaluated parameters were the levels of the following cytokines: IL-1beta, IL-4, IL-6, IL-8, IL-12, IFN-gamma and TNF-alpha. Cytokines were recovered from rhinosinusal lavage and measured by immunoassays. Nasal cytology was also performed in all subjects and inflammatory cells were counted by conventional staining.

RESULTS

Allergic subjects showed a significant increase of IL-4 (P < 0.01) and TNF-alpha (P < 0.05) and a significant decrease of IL-12 (P < 0.05) and of IFN-gamma (P < 0.0001), whereas IL-1beta, IL-6 and IL-8 were not significantly increased. Non-allergic children showed a significant increase of IL-4 (P < 0.05) and a significant decrease of IFN-gamma (P < 0.0001), IL-12 was not significantly decreased, and IL-1beta, IL-6 and IL-8 were not significantly increased. A significant inflammatory infiltrate was present in all asthmatic children. Significant correlations were demonstrated between IL-4 and IL-12 (P < 0.001), IL-12 and IFN-gamma (P < 0.001), IL-8 and neutrophils (P < 0.01), and TNF-alpha and monocytes/macrophages (P < 0.05), in allergic asthmatics. IL-4 and IL-12 were significantly correlated (P < 0.05) as well as IL-8 and neutrophils (P < 0.01) in non-allergic asthmatics.

CONCLUSION

This study shows that allergic asthmatic children with chronic rhinosinusitis have a typical Th2 cytokine pattern, but also non-allergic asthmatic children share a similar pattern. These findings would suggest the existence of a common pathophysiological mechanism shared by upper and lower airways and are consistent with the concept of united airways disease.

[Pseudoathetosis after medullar and pontine hemorrhage]

INTRODUCTION

Athetosis is a slow and purposeless involuntary movement which changes in frequency, severity. The term pseudoathetosis is used when this movement is associated with proprioceptive sensory impairment.

CLINICAL CASE

A 63 year old man developed right medulla and pons hemorrhage and presented loss of proprioception in left hemibody and athetosis movements in left hand.

CONCLUSION

We report a case of pseudoathetosis associated with loss of proprioceptive sensation.

[A case of Isaacs' syndrome associated with dextrocardia]

INTRODUCTION

Isaacs syndrome is a disorder of unknown etiology characterized by muscular rigidity, cramps and myokymias. Described by Isaacs in 1961 and called by him as continuous muscular activity syndrome. There are few reports in Latino american countries.

CLINICAL CASE

A 31 year-old man with sustained muscular contractions in lower limbs and diffuse myokymias since he was eighteen-year old. Dextrocardia was disclosed on clinical examination.

CONCLUSION

We report the case of a patient with Isaacs syndrome and dextrocardia.

[Chin tremor in a peruvian family]

INTRODUCTION

Chin tremor is an uncommon hereditary autosomic dominant disorder, characterized by involuntary, episodic, and repetitive movements involving chin muscles, stimulated by stress. It was first described by Massaro in 1894 like geniospasmo . The most reported cases are from Europeans or Americans families.

CLINICAL CASE

A 53 years old man with chin tremor since childhood.

CONCLUSIONS

We report the first Peruvian family with chin tremor without European nor American ascendancy with six affected members in four generations.

Fexofenadine reduces nasal congestion in perennial allergic rhinitis

BACKGROUND

Nasal congestion is the predominant symptom in perennial allergic rhinitis (PAR), and it seems to be mainly related to the late-phase inflammatory events. The present pilot study aimed to evaluate the therapeutic effect exerted by fexofenadine in patients with PAR due to mite allergy.

METHODS

This study was a parallel, double-blind, randomized, three-arm (1:1:1), placebo-controlled study. Thirty-one subjects with PAR were enrolled and received double-blind medication: fexofenadine 120 or 180 mg, or placebo, once a day for 28 days.

RESULTS

The total symptom score was reduced by fexofenadine (both dosages) at V2 (P=0.007), whereas placebo did not modify it. Nasal congestion decreased after 1 week of treatment with fexofenadine 120 (P=0.027) and 180 (P=0.01), but not with placebo (P=NS). At V3, fexofenadine (both dosages) significantly reduced nasal congestion (P=0.011 and P=0.007, respectively), by placebo did not show any significant effect.

CONCLUSIONS

This pilot study represents the first evidence of the efficacy of fexofenadine in PAR, and also the control of the nasal congestion. We suggest performing larger trials to confirm these preliminary findings.

Effect of substitution pattern on 1H, 13C NMR chemical shifts and 1J(CH) coupling constants in heparin derivatives

1H, 13C NMR chemical shifts and 1J(CH) coupling constants were measured for derivatives of heparin containing various sulfation patterns. 1H and 13C chemical shifts varied considerably after introducing electronegative sulfate groups. Chemical shifts of protons linked to carbons changed by up to 1 ppm on substitution with O- and N-sulfate or acetyl groups. Differences up to 10 ppm were detected for 13C chemical shifts in substituted glucosamine, but a less clear dependence was found in iduronate. 1J(CH) values formed two groups, corresponding to either sulfation or non-sulfation at positions 2 and 3 of glucosamine. O-sulfation caused increases up to 6 Hz in 1J(CH) and N-sulfation decreases up to 4 Hz. N-acetylation gave similar 1J(CH) values to N-sulfation. At positions 2 and 3 of iduronate the trend was less marked; 1J(CH) for O-sulfated positions usually increasing. Introduction of sulfate groups influences chemical shift and 1J(CH) values at the position of substitution, but also at more remote positions. 1J(CH) at the glycosidic linkage positions varied between free-amino and N-sulfated compounds, by up to 9 Hz. These results and changes in chemical shift values suggest that iduronate residues and the glycosidic linkages are affected, indicating overall conformational change. This may have important implications for biological activities.

[Becker's myotonia in Peru]

INTRODUCTION

The word myotonia was used for the first time by Strümpell in 1891. Diseases associated with this symptom are called myotonias. They are classified on the basis of their clinical features in: congenita myotonia, paramyotonia congenita, myotonic dystrophy and Schwartz-Jampel syndrome. Becker's myotonia is a generalized congenita nondystrophic myotonia transmitted as an autosomal recessive trait and caused by allelic mutation of the gene encoding the chloride channel CLC-1 of the skeletal muscle fiber surface membrane, localized on chromosome 7q35. At the present time, nondystrophic myotonias are referred as channelopathies.

CLINICAL CASE

We describe a case of generalized myotonia in a Peruvian young male, descending of Europeans, without familial history.

CONCLUSIONS

We discuss his clinical symptoms, laboratory and electrophysiologic findings, differential diagnosis, and response to the treatment with carbamazepine. We report the first case of Becker's myotonia in Peru.

Tourette's syndrome and neurofibromatosis type 1

The case of an 11-year-old male with clinical features compatible with a diagnosis of Tourette's syndrome and neurofibromatosis type 1 is reported. Magnetic resonance imaging revealed bilateral pallidal hyperintensities, which may be related to the tic disorder.

Solid state NMR spectroscopy study of molecular motion in cyclomaltoheptaose (beta-cyclodextrin) crosslinked with epichlorohydrin

Dry and hydrated insoluble cyclomaltoheptaose (beta-cyclodextrin, beta-CD) polymers have been investigated by solid state 13C NMR spectroscopy techniques such as cross polarization/magic angle spinning with dipolar decoupling (CP/MAS), magic angle spinning both with (DD-MAS) and without (MAS) dipolar decoupling and CP/MAS dipolar dephasing (dd-CP/MAS) to allow the assignment of the main 13C signals. In the solid state, the presence of water in the samples resulted in a better resolution reflecting increased mobility. Two distinct components (crosslinked beta-CD and polymerized epichlorohydrin) have been found. The molecular mobility of these two components has been analyzed in terms of relaxation parameters such as 13C spin lattice relaxation (T1) and 1H spin lattice relaxation in the rotating frame (T1 rho). The T1 values of the polymers show that the beta-CD trapped inside the polymers does not seem to undergo changes in its mobility whatever the amount of epichlorohydrin. The addition of water to beta-CD significantly increases the T1 values reflecting strong interaction between beta-CD and the solvent. The T1P values obtained reflect the homogeneous nature of the materials.

Pediatric falls from heights

Injuries resulting from falls from heights still constitute a significant portion of urban trauma. At this pediatric trauma center, 70 children were admitted from 1985 to 1988 after sustaining a fall of 10 feet or greater or at least one story. The mean patient age was 5 years and 68% of the patients were boys. Seventy-eight percent of falls occurred from 2 stories or less and usually took place at or near the home. Most patients sustained a single major injury and all survived. The majority of injuries involved the head or skeleton and residual functional deficits were uncommon. The incidence of falls from heights has remained high in urban areas despite public education and building codes that require window guards and safety rails.

Hemodynamics of revascularization for iliofemoral venous occlusion: a short-term canine model

A short-term canine model of lower extremity venous hypertension was created to study the hemodynamics of crossfemoral venous bypass grafts (CFB). Specifically, the hemodynamic effects of bypass conduit diameter and adjunctive arteriovenous fistulas (AVFs) were investigated. Unilateral hind limb venous hypertension was produced by iliofemoral venous ligation in six groups of five greyhounds each. Group I had venous ligation alone. CFBs were constructed in the remaining five groups: group II, 3 mm bypass conduit alone; group III, 3 mm bypass plus sequential AVF; group IV, 3 mm bypass plus caudad AVF; group V, 3 mm bypass plus cephalad AVF; group VI, 6 mm bypass conduit alone. Venous hypertension was significantly reduced by CFB (group II, p less than 0.025; group VI, p less than 0.001); increasing the diameter of the bypass conduit from 3 to 6 mm produced significantly greater graft flow (p less than 0.05), while completely relieving venous hypertension. Addition of adjunctive AVFs significantly augmented graft flow (p less than 0.001) but tended to aggravate ipsilateral venous hypertension (group III, p less than 0.01; group IV increase, NSS; group V, p less than 0.001). During the 4 hours of pressure monitoring, venous hypertension diminished significantly (p less than 0.05) with the sequential AVF but not with the other AVF. We conclude that (1) AVFs may be required for adequate graft flow if a small-diameter (3 mm) bypass conduit is used to relieve venous hypertension; (2) adjunctive AVFs aggravate venous hypertension; (3) sequential AVFs seem to be the most hemodynamically efficacious; (4) AVFs may not be necessary if a large, isodiametric (6 mm) conduit is used.

Canine model for surgical correction of chronic venous hypertension

A chronic model of venous hypertension was created by iliofemoral venous ligation in the left hindlimb of eight greyhounds (right limb control). Prior to ligation, immediately postligation (T0), and at 2, 4, 6, and 15 weeks postligation (T2-T15), bilateral hindlimb venous pressures were measured at rest. At T2-T15, exercise pressures were measured for 5 min after hindlimb muscle contraction induced under sedation by tetanic (20 sec, 50 Hz, 8 mA) stimulus (S30-S300 sec). Resting and exercise pressures were significantly higher in the ligated hindlimb at all time intervals (resting, P less than 0.001 at T0, T2, T4, T6, and P less than 0.025 at T15; exercise, P less than 0.001 for S30-S300 at T2-T15). In five of the animals at 15 weeks, a cross-femoral venous bypass (CFB) with adjacent adjuvant arteriovenous fistula (AVF) was constructed using autologous external jugular vein. Venous pressures were measured at 2 and 6 weeks post-CFB both at rest and after tetanic muscle stimulation. At 2 weeks, venous pressure in the ligated limb was significantly higher than that in control only after exercise (P less than 0.025 at S30-S120; P less than 0.05 at S150-S180; NS at S240-S300). At 6 weeks, venous pressures were not significantly different at rest or with exercise. All five grafts were patent at 6 weeks. Three of five dogs then successfully underwent ligation of the AVF. At 2 weeks post-AVF ligation there was no difference in resting or exercise venous pressure in the ligated limb compared to control. At 6 weeks post-AVF ligation only two dogs remained for monitoring and in these there was no trend toward venous hypertension in the ligated hindlimb. Graft patency was maintained despite AVF ligation.

[Alkyl and aryl derivatives of isoquinoline. II. Synthesis and pharmacologic activity of dialkylaminoalkyl esters of 1-chloro-3-carboxy-4-methylisoquinoline and the corresponding 4-phenyl derivative]

The synthesis of a series of dialkylaminoalkylic esters of 1-chloro-3-carboxy-4-methylisoquinoline and of 1-chloro-3-carboxy-4-phenylisoquinoline is described. The pharmacological activity of some of these compounds was studied. The morpholinoethylester of 1-chloro-3-carboxy-4-methylisoquinoline (VIIa), dimethylaminoethylester (VIIb) and diethylaminoethylester (VIIc) showed a good antispasmodic activity. 4-Phenyl-derivatives (XVa), (XVb), (XVc) were more active than analogous 4-methyl derivatives; particularly the diethylaminoethylester of 1-chloro-3-carboxy-4-phenylisoquinoline (XVc) showed an antagonist effect against spasmogens similar to that of papaverine.

Synthesis and biological evaluation of some 5-aryl-2-amino-1,3,4-oxa(thia)diazoles

Three series of 5-aryl-2-amino or 2-amino substituted 1,3,4-oxadiazoles (IV-XVIII) were prepared together with the corresponding series of the analogous 5-aryl-2-amino-1,3,4-thiadiazoles (XIX-XXXIII). The purpose of this work is two-fold: to study their pharmacological action in relation to the substituents bound to the positions -2 and -5, and to observe whether the isosteric substitution of the oxygen of he oxadiazolic nucleus with the sulfur leading to a thiadiazolic nucleus causes any activity variation. The AA. report and discuss the results obtained studying the antifungal as well as the antiinflammatory and antipyretic activity of the synthetized compounds.