Segmental spinal dysgenesis: a report of early surgical intervention and outcome in a 14-month-old child.

Segmental spinal dysgenesis is a rare spinal deformity that is the result of failure of formation resulting in some cases spondyloptosis and neurological dysfunction usually at the thoracolumbar junction. There is little known concerning surgical intervention and timing in these patients. The goal of this case report is to present a case involving 14 months old diagnosed with segmental spinal dysgenesis with stenosis at the thoracolumbar junction soon after birth, treated with definitive posterior spinal fusion and subsequent follow-up.

Prognostic value of analysing the bioimpedance vector for patients hospitalised for acute decompensated heart failure: A validation cohort.

OBJECTIVES: To assess the prognostic impact of the bioimpedance vector (bioelectrical impedance vector analysis [BIVA]) for patients hospitalized for heart failure (HF). MATERIAL AND METHODS: A prospective cohort of 105 patients hospitalized for HF. BIVA was performed prior to discharge, and the final sample was divided into 3 groups according to the value obtained: hyperhydration [hyperH] (>74.3%), normal hydration [normoH] (72.7-74.3%) and dehydration [desH] (<72.7%). In the follow-up, total mortality and readmissions for HF were considered adverse events. RESULTS: A higher incidence of events was observed among the patients with hyperH and desH compared with those with normoH (Kaplan-Meier: log-rank, 2.1; p=.04), with an increase in independent risk in the multivariate analysis (HR, 2.6 [1.05-6.44]; p=.039). CONCLUSIONS: BIVA helps stratify the risk of readmission for HF and total mortality in the long-term follow-up of patients hospitalized for HF.

Prescription of oral anticoagulation for patients with atrial fibrillation and previous hospitalization in a cardiology department. Experience in actual practice in a tertiary hospital. / Prescripción de anticoagulación oral en pacientes con fibrilación auricular e ingreso previo en un servicio de cardiología. Experiencia en un hospital terciario.

INTRODUCTION: Atrial fibrillation is the main reason for oral anticoagulation in our community. New oral anticoagulants (NOACs) overcome the disadvantages of vitamin K antagonists (VKAs), although there are scarce data on its use in our community. The aim of our study was to assess the use of NOACs and anticoagulation control using VKA as measured by the time within the therapeutic range (TTR) in an actual clinical scenario. METHODS: A retrospective cohort analysis was conducted of 816 patients admitted to cardiology over a period of 3 years, with a diagnosis of atrial fibrillation and anticoagulant treatment at discharge. We assessed the percentage of patients prescribed NOACs and the TTR with VKA. We compared safety and efficacy events during the 15-month follow-up among the patients prescribed NOAC, those prescribed VKA with a good TTR and those with a poor TTR. RESULTS: The percentage of patients prescribed NOAC was 7.6%. Serial INR measurements found that 71.3% of patients had a poor TTR. Although the groups were not comparable, a higher incidence of the combined event was observed in those treated with VKA and a poor TTR compared with those prescribed NOAC (p=.01). CONCLUSIONS: For patients with a previous hospitalization in cardiology in a tertiary hospital and a diagnosis of atrial fibrillation, the rate of NOAC prescription is low, and the TTR with VKA was poor.

Identification and localization of the first glutaredoxin in leaves of a higher plant.

Glutaredoxin(thioltransferase) has been identified and purified to homogeneity from spinach leaves. Its cytosolic localization was demonstrated by chromatographic and immunological analysis of extracts from isolated spinach chloroplasts and mitochondria, respectively. Spinach glutaredoxin shows a significant crossreactivity with antibodies raised against E. coli glutaredoxin and possesses a specific thioltransferase activity comparable to that of the E. coli protein. Minor thioltransferase activities (less than 10% of total leaf activity) have been observed in spinach chloroplasts which are probably due to the presence of trypsin inhibitor and thioredoxins (TRf and TRm).

Dehydroascorbate and dehydroascorbate reductase are phantom indicators of oxidative stress in plants.

In many physiological studies dehydroascorbate (DHA) reductase is regarded as one of the chloroplast enzymes involved in the protection against oxidative stress. Here, evidence is presented that plant cells do not possess a specific DHA reductase. The DHA reductase activities measured in plant extracts are due to side reactions of proteins containing redox-active dicysteine sites. Native gel electrophoresis combined with specific activity staining revealed three different proteins with DHA reductase activity in leaf and chloroplast extracts. These proteins have been identified as thioredoxins and trypsin inhibitors (Kunitz type) by Western blot analysis. The essential regulatory functions of thioredoxins in chloroplast metabolism are strongly inhibited in the presence of as little as 50 microM DHA. Thus, the intracellular DHA concentration should be kept below 50 microM but not all proteins with DHA reductase activity are effective enough for this purpose. A specific DHA reductase is frequently demanded as part of the enzymatic equipment to avoid oxidative stress. We argue that this is not necessary because in chloroplasts DHA does not accumulate to any significant extent due to the high activities of monodehydroascorbate reductase and of reduced ferredoxin.

Identification of conserved and variant epitopes of human immunodeficiency virus type 1 (HIV-1) gp120 by human monoclonal antibodies produced by EBV-transformed cell lines.

Using Epstein-Barr virus (EBV) transformation of B cells isolated from peripheral blood of two asymptomatic human immunodeficiency virus type 1-(HIV-1) infected subjects, we have produced four IgG1 human monoclonal antibodies (HMAbs) that bind to HIV-1 gp120, as determined by Western blot analysis. Two of these HMAbs, designated N70-1.5e and N70-2.3a, react with epitopes of gp120 expressed by all strains tested thus far, and therefore, appear to identify conserved epitopes. The other two HMAbs, K24-3b and N70-1.9b, identify variant epitopes; K24-3b binds to an epitope which is absent from two strains but heterogeneously expressed in eight other strains; N70-1.9b binds to an epitope that is found in relatively few strains. We also describe a novel immunoassay in which viral glycoproteins, produced by HIV-1-infected cells grown in serum-free medium, are affinity immobilized in Concanavalin A-coated wells of enzyme-linked immunosorbent assay (ELISA) plates. This method greatly facilitates the preparation of solid-phase HIV envelope glycoproteins from multiple virus strains and screening immunoassays based on this method are highly sensitive and effective in detecting antibodies to gp120.

[Survival in patients with sick sinus syndrome and artificial pacemaker. Determining clinical factors]. / Supervivencia en pacientes con enfermedad del nodo sinusal portadores de marcapasos. Factores clínicos determinantes.

INTRODUCTION AND OBJECTIVE: The hypothesis that ventricular pacing is the most important factor in the survival of patients with Sick Sinus Syndrome remains controversial. The aim of this report was to determine independent clinical variables to predict survival in paced SSS patients. METHODS: Retrospective, nonrandomized study of 153 patients with a mean age of 69 +/- 11 years, who received an initial pacemaker for Sick Sinus Syndrome between 1980 and 1994: 65 physiologic pacing (32 dual chamber, 33 atrial) and 88 ventricular pacing mode. After a maximum follow up of 177 months (median 57 months) the end point was total mortality. RESULTS: Total mortality was 21%. Using univariate analysis, single chamber ventricular pacing, age > or = 70 years and NYHA > or = 2, was associated with a higher risk for total mortality (4 times increased risk for ventricular pacing compared to other pacing modalities). Independent predictors using multivariate analysis were: 1) NYHA > or = 2 (p < 0.05). 2) Coronary artery disease (p < 0.01). 3) Chronic obstructive pulmonary disease (p < 0.05) and 4) Gender (p < 0.05). CONCLUSIONS: Mortality in patients with the Sick Sinus Syndrome is strongly predicted by preimplant baseline clinical variables. Our data indicate that the role of ventricular pacing mode remains inconclusive. A large, randomized study is necessary to confirm these results.

[The incidence and significance of late potentials in patients with aborted sudden death]. / Incidencia y significado de los potenciales tardíos en pacientes con muerte súbita abortada.

BACKGROUND: Reentrant ventricular tachycardia and fibrillation probably have different electrophysiological bases. Regional conduction delay during sinus rhythm seems to be greatest in patients with spontaneous sustained ventricular tachycardia than in patients with spontaneous sustained ventricular fibrillation. We investigated the prevalence and significance of late potentials in patients with documented VT or VF in the setting of coronary diseases and other organic heart diseases. PATIENTS AND METHODS: Nineteen patients with a history of spontaneous sustained ventricular tachycardia (11 patients) or fibrillation (8 patients) were studied with signal-averaged ECG. All patients had been resuscitated of sudden cardiac death. All recordings were made in sinus rhythm in an antiarrhythmic free state following the recommendations of the Committee of the European Society of Cardiology for data acquisition and analysis of ventricular late potentials using Signal Averaged Electrocardiography. The relationship between this late potentials and tachyarrhythmia inducibility during electrophysiologic study were established. RESULTS: Abnormal late potentials were found in 79% of patients with sudden cardiac death. Patients with spontaneous ventricular tachycardia had a longer ventricular activation time in sinus rhythm than did patients with spontaneous ventricular fibrillation, but this difference did not reach statistic significance. The only analysis of late potentials could not discern the mechanism of sudden cardiac death. However when sudden cardiac death was caused by a spontaneous ventricular tachycardia, a good correlation between abnormal late potentials and induced ventricular tachycardia by programmed stimulation was found. Quantitative indices of late potentials did not correlate with ventricular tachycardia cycle length. CONCLUSIONS: 1) We have found and elevated incidence of abnormal late potentials in patients with sudden cardiac death, and 2) only when the mechanism of sudden cardiac death was a spontaneous VT, we were able to correlate abnormal late potential with provoked ventricular tachycardia during electrophysiologic study.

"Haemostasis time", a modified bleeding time test and its comparison with the Duke and Ivy/template bleeding times. I. Normal values, application in thrombocytopenic patients and evaluation of heparin and aspirin effects.

The occlusion time ("haemostasis time" - HT) of a thin, short cannula inserted into the cubital vein, was compared with the skin bleeding times of the Duke and Ivy/template techniques. 25 male and 25 female volunteers without a history of bleeding were divided into 5 equally large age groups ranging from 10 to over 50 years of age. They exhibited a range of 46 s-6 min 38 s (95% tolerance interval), while the Duke and Ivy/template bleeding times, which were simultaneously determined, corresponded to values given by other authors. HT is different from the skin bleeding times in that endothelium is replaced by a standard foreign surface which allows better standardization of the method. Similar results were obtained with HT compared to the skin bleeding times. These and a similar, non-significant heparin response with all three techniques suggest that HT is not more influenced by clotting factors than the Duke and Ivy/template bleeding times and, indeed, may be regarded as a bleeding time modification. HT, like both of the skin bleeding times, reflected lowered platelet counts and is even more sensitive in this respect. As tested in a group of 20 male and 20 female volunteers, HT showed a significant prolongation two hours after ingestion of 1 g aspirin. While male individuals exhibited longer bleeding times than females with the Ivy/template technique (sex-related difference p = 0.01), no male to female differences were found both with HT and the Duke bleeding time. HT is easy to perform, inexpensive, leaves no scars and is safe even for the patient with severe bleeding. Moreover, compared to the skin bleeding times, it permits a differential evaluation of vessel wall and tissue effects.

Identification of phytoestrogens in the urine of male dogs.

It is becoming increasingly apparent that dietary factors may play a role in the etiology of hormone dependent neoplasias. It has been hypothesized that estrogens play some role in the etiology of benign prostatic hyperplasia (BPH) in the canine. The presence of estrogen receptor binding activity in a fraction of canine urine purified by high performance liquid chromatography (HPLC) that did not correspond to estriol, estradiol, estrone or any of their primary metabolites was observed in the present study. We used thermospray-mass spectrometry and GC-MS to identify the phytoestrogens daidzein, equol, formononetin and genistein in HPLC purified fractions of urine obtained from male beagles. Using the same techniques we also confirmed the presence of daidzein and genistein in the commercial diet fed to these same dogs. Using the immature rat uterine cytosol estrogen receptor assay, relative binding affinities of 0.08, 1.1, less than 0.01 and 3.9% were obtained for daidzein, equol, formononetin and genistein, respectively when compared to estradiol (100%). In conclusion, phytoestrogens are present in urine of male beagles. Moreover, the commercial diet fed to these dogs contains isoflavones which can be converted to equol by intestinal microflora. These results suggest the need for investigations of phytoestrogens (e.g. equol) excreted into the urine daily and its relationship to the incidence and severity of BPH in the dog.

Solvent-sample interactions in thermospray mass spectrometry of antineoplastic nitrogen mustards.

Conditions are reported for the optimization of thermospray mass spectrometric analysis of antineoplastic nitrogen mustard alkylating agents. In aqueous ammonium acetate mobile phase, multiple sequential solvolytic reactions occur with these highly labile compounds, and protonated molecular ions of the reaction products are observed. However, when high proportions of acetonitrile or other organic modifier are added to the mobile phase, solvolytic reactions are much reduced and abundant protonated molecular ions are detected. One exception to these observations is phosphoramide mustard, which solvolyses under all conditions attempted. A lower limit for detection of melphalan using direct injection and summing the ion current between m/z 120 and 870 is about 150 ng. Successful thermospray liquid chromatography/mass spectrometry of these compounds should be possible using high percentages of methanol in the mobile phase or increasing the organic content by post-column solvent modification.

Effects of propafenone on induction and maintenance of atrioventricular nodal reentrant tachycardia.

Electrophysiologic studies were performed in 10 patients with atrioventricular (A-V) nodal reentrant paroxysmal supraventricular tachycardias (PSVT), before and after intravenous administration of propafenone (1.5 mg/kg). All patients utilized an A-V nodal slow pathway for anterograde conduction and an A-V nodal fast pathway for retrograde conduction of the reentrant impulse. Propafenone depressed retrograde fast pathway conduction which was manifested by: 1) complete V-A block at all ventricular paced cycle lengths after propafenone in 3 cases; 2) increase in mean +/- SD of ventricular paced cycle length producing V-A block from less than 308 +/- 37 ms to 432 +/- 63 ms in the remaining 7 patients. Nine of the 10 patients had induction of sustained PSVT before propafenone. In 7 of the 9, PSVT could not be induced or sustained after propafenone, reflecting depression of the retrograde fast pathway conduction with either absence of atrial echoes (5 patients) or induction of nonsustained PSVT, with termination occurring after the QRS (2 patients). In 1 patient, single atrial echoes were induced before propafenone but none were noted after the drug. In only 2 patients was a sustained PSVT inducible after propafenone. In conclusion, propafenone inhibited induction of sustained A-V nodal reentrant PSVT in most patients, reflecting depression of retrograde A-V nodal fast pathway conduction.

Transvenous ablation with high frequency energy for atrioventricular junctional (AV nodal) reentrant tachycardia.

We performed transcatheter AV junction ablation with high frequency energy in four patients with AV nodal reentrant tachycardia where extensive trials of several antiarrhythmic drugs failed to prevent further recurrences of tachycardia. Initially high frequency catheter ablation induced complete AV block in all patients. A recuperation of AV 1:1 conduction followed some time later, persisting in follow-up. No complications have been encountered in either the acute phase or the follow-up (from 6 to 8 months; mean +/- SD: 8.7 +/- 2.5 months). The electrophysiological study was carried out 6 weeks following ablation, and all patients showed AV 1:1 conduction. No dual nodal pathway was encountered and no tachycardia could be triggered. With refinement of the method, the potential application of high frequency energy to interrupt intranodal or perinodal connections responsible for reentrant supraventricular tachycardia or to retard AV nodal conduction appears promising.

Induction of partial alterations in atrioventricular conduction in dogs by percutaneous emission of high-frequency currents.

Ten anesthetized dogs were studied in an attempt to provoke partial alterations in atrioventricular (AV) conduction by high-frequency current (HFC) transcatheter ablation. A discharge power (10 to 15 W) was used for less than 5 seconds after reaching complete AV block (CAVB). The catheter was placed within an area having an A/V ratio = 1 with His bundle deflection. If following discharge, no appreciable lengthening an AH, AV nodal block cycle length (Wenckebach point, WP), and/or functional nodal refractory period (FRPAVN) was observed, the procedure was repeated. Four dogs (group I) were killed immediately, and the other six (group II) after 2 to 4 weeks. The AH interval, WP, and FRPAVN were found to prolong significantly following HFC, without variations in HV interval. In group II, two dogs progressed to CAVB, whereas the other four maintained 1:1 AV conduction with AH, WP, and FRPAVN greater than before the power discharge. In conclusion, HFC is an efficient technique to induce partial alterations in AV conduction, since the discharge can be adjusted and the ablation can be localized to specific regions.

Observations on variability of atrioventricular nodal conduction in man and the dual-pathway response.

A study was made of nodal conduction times of atrial stimuli with fixed coupling intervals, in 23 patients divided into two groups according to their atrial stimulus test response: Group I (continuous AV node function curve; 17 cases) and Group II (dual AV node pathway; six cases). The stimulation protocol involved the delivery of 75 stimuli with a fixed coupling interval 20 ms greater than the effective refractory period (ERP) of the AV node (Group I) or fast pathway (Group II). The atrial coupling intervals (A1A2) and node conduction times (A2H2) were measured. An evaluation was made of the dispersion of intervals with range (R) and of the distribution of A2H2 times (X2 test). In both Groups, R (A2H2) was greater than R(A1A2) (P less than 0.05); R(A2H2) in Group II was greater than R(A2H2) in Group I (P less than 0.001). In Group I the distribution of A2H2 was non-normal in four cases and bimodal in five; in Group II the distribution was non-normal and bimodal in all cases. It is concluded that: (1) the AV node generates a dispersion in its conduction times in the vicinity of its ERP, although the nodal conduction curve is continuous; and (2) the so-called dual pathway may constitute an exaggeration of AV node response inhomogeneity.