The inhibitory effect of an arginine bicarbonate/calcium carbonate CaviStat-containing dentifrice on the development of dental caries in Venezuelan school children

OBJECTIVE

This study assessed the effect of an arginine bicarbonate/calcium carbonate (CaviStat)-containing dentifrice on caries development, mainly in 11- to 12-year-old Venezuelan children over a two-year period.

METHODOLOGY

Children (726) with a DMFT between 3 and 6 were examined at baseline, six months, and one and two years using a mirror, probe, and DMFS scoring. Subjects who completed the study consisted of two groups; 304 test and 297 control. The test group received a CaviStat-containing dentifrice, and the controls used a commercially available 1100 ppm fluoride toothpaste. All subjects were instructed to brush three times a day for 1 minute followed by swishing for 30 seconds.

RESULTS

After six months, the mean DMFS scores increased only slightly from baseline in both groups, 6.93 +/- 0.22 in the control and 6.59 +/- 0.22 in the test subjects. After one year, the mean DMFS score in the control group rose to 8.00 +/- 0.24 and leveled off at 7.92 +/- 0.30 at two years. In contrast, the mean DMFS score in the test group decreased to 5.50 +/- 0.24 after one year before rising to 6.99 +/- 0.28 at two years. DMFS difference between the two groups was highly significant (p < 0.001), but mainly due to the large difference seen at one year. Dissection of the data showed that the erupted first molars dominated the overall DMFS changes. At the beginning of this study, first molar scores started at high values and showed a pattern thereafter like that seen for the total data. In contrast, premolars/molars, which erupt 4-6 years later (and at the start of the study had a mean DMFS score slightly above zero), showed a clear rise in the DMFS score in the control group during the first year of the study, which continued to rise until the end of the investigation. In contrast, the CaviStat group showed no change in the premolar/second molar DMFS score from baseline during the first year (giving the impression of 100% inhibition at one year), but showed a delayed rise thereafter that paralleled that seen in the controls between one and two years (58.3% inhibition at two years). Reversal of the development of early dental caries lesions in the CaviStat subjects and limitations of the diagnosis of very early caries lesions with standard dental explorers was suggested for the interesting first molar, first year data. Inhibition of caries initiation and caries progression in the CaviStat group was also observed and easier to see in the premolar/second molar, second year data where the DMFS scores were very low at baseline and reversals are not a significant issue. The results were subjected to statistical analysis including analysis of covariance. Largely because of the first year and first molar data, the difference between control and experimental groups was highly significant (p < 0.001). Similar comparison with the later-erupting premolar/molar teeth showed the CaviStat effect was also significant but at a lower level (p < 0.05). The differences could not be due to examiner error since the Kappa for 10% of the subjects randomly selected and re-examined was 0.898 overall and 0.914 for the first molar data. The data also suggested CaviStat inhibition of caries progression because of a slower rate of rise of missing+filled teeth in the CaviStat vs. the control group (p < 0.05).

CONCLUSION

A CaviStat-containing toothpaste was more effective both clinically and statistically in inhibiting caries initiation and progression than the fluoride toothpaste control, and manifested its effects differently in the already-erupted first molars than in the later-erupting premolars and second molars.

[Resolution for the determination and certification of death in Cuba]

AIMS

In this paper we report on Public Health Resolution 90, which regulates the determination and certification of death in Cuba.

METHOD

Public Health Resolution 90 is of great social importance in our country since it allows the determination and certification of death to be lawfully regulated throughout the whole territory. It is the fruit of over ten years work by a national commission which was set up for that purpose. This resolution includes a series of features that are unprecedented on an international level. By legalising all the aspects linked with the determination and certification of death by means of a ministerial resolution (Ministry of Public Health), and not through a law passed by Parliament, no obstacles are created to prevent it from being reassessed and changed in the future in order to keep up with scientific and technical progress. Unlike most legislation throughout the world, this resolution does not regulate the determination of death, or brain death, linked with organ transplants. In fact, the word transplants does not appear anywhere in the resolution. The clinical and instrumental criteria for determining death were grouped under the heading of the well known true signs of death , but included a true sign based on the irreversible loss of brain functions . Although the irreversible absence of respiratory and circulatory functions, together with the presence of post mortem changes, were included as true signs, the national commission concluded that the death of an individual can only be defined in terms of the irreversible loss of brain functions . The clinical and instrumental criteria for determining death are included in two annexes to the resolution, which must be reviewed from time to time by the National Commission for the Determination of Death, as and when scientific and technical progress makes it necessary to do so. Among the instrumental tests used as a diagnostic aid for the irreversible loss of brain functions and, for perhaps the first time in the world, a battery of tests made up of multimodal evoked potentials and electroretinography has been included.

CONCLUSIONS

Public Health Resolution 90 offers the legal framework for regulating the determination and certification of death in Cuba.

Predicting outcome in acute stroke: a comparison between QEEG and the Canadian Neurological Scale

OBJECTIVE

To determine and compare the predictive value of quantitative EEG (QEEG) and the Canadian Neurological Scale (CaNS), in patients with an acute cerebral stroke.

METHODOLOGY

Twenty-eight patients were studied with the diagnosis of acute ischemic middle cerebral artery stroke, within the first 72 hours of clinical evolution. Thirty-seven EEGs and clinical evaluations were collected: 13 during the first 24 hours after stroke onset, 9 between 24-48 hours and 15 between 48-72 hours. The QEEG studied variables were: the Z values (maximum, minimum and the Z medians from the 5 nearest points to each one) of absolute energies (AE) from the 4 classic frequencies bands. The clinical scale showed a smaller percent of correct prognosis than QEEG variables.

CONCLUSIONS

QEEG was demonstrated to be a powerful tool to predict the degree of residual functional disabilities after an acute ischemic stroke and showed a higher prognostic value than CaNS when they are performed within the first 72 hours of brain infarct.

[Usefulness of P300 as a tool for diagnosing alterations in sustained attention in ischemic cerebrovascular disease]

INTRODUCTION

Event related potentials, and especially the component P300, can be used to achieve greater precision and sensitivity in the cognitive evaluation of patients. They also enable us to obtain more accurate information about deficiencies in sustained attention, which is a cognitive function associated with the generation of the above mentioned component. Furthermore, the study of disorders triggered off by cerebrovascular disease must be given priority because of the high incidence with which they occur.

PATIENTS AND METHODS

We studied four groups of individuals divided according to the localization of the lesion and the etiopatogenic mechanism involved (10 patients with right parietal atherothrombotic infarction, 10 patients with left parietal atherothrombotic infarction, 10 patients with lacunar infarction, 10 paired healthy controls). They were administered a classic test for obtaining P300, which evaluates sustained attention.

RESULTS

Patients with cerebral infarction in the right hemisphere presented alterations in the functions evaluated, since they showed more omissions, gave fewer correct answers, the values for latency were significantly increased in Fz derivation and amplitude values were reduced in Pz, as compared to healthy controls. Individuals with left cerebral infarction, however, showed no significant differences with regard to the controls. People with lacunar infarction made less mistakes and omissions, and scored more correct answers than those that had suffered right or left infarction. Their amplitude values were also higher than the values of the individuals with a right lesion in Pz derivation but showed no differences as regards the controls.

CONCLUSIONS

These results provide new data on the cognitive mechanisms that are affected during a right parietal lesion and demonstrate the sensitivity of P300 in detecting alterations in sustained attention in individuals that differ as regards not only the localization of the lesion but also the type of etiopathogenic mechanism involved.

Shock reduction using antitachycardia pacing for spontaneous rapid ventricular tachycardia in patients with coronary artery disease

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) can terminate some ventricular tachycardias (VTs) painlessly with antitachycardia pacing (ATP). ATP has not routinely been applied for VT >188 bpm because of concerns about efficacy, risk of acceleration, and delay of definitive shock therapy. This prospective, multicenter study evaluated the efficacy of empirical ATP to terminate fast VT (FVT; >188 bpm).

METHODS AND RESULTS

Two hundred twenty coronary artery disease patients received ICDs for standard indications. Empirical, standardized therapy was programmed so that all FVT episodes (average cycle length [CL] 240 to 320 ms, 250 to 188 bpm) were treated with 2 ATP sequences (8-pulse burst pacing train at 88% of the FVT CL) before shock delivery. A total of 1100 episodes of spontaneous ventricular tachyarrhythmias occurred during a mean of 6.9+/-3.6 months of follow-up. Fifty-seven percent were classified as slow VT (CL>/=320 ms), 40% as FVT (240 ms</=CL<320 ms), and 3% as ventricular fibrillation (CL<240 ms). A total of 446 FVT episodes, mean CL=301+/-24 ms, occurred in 52 patients (median 2 episodes per patient). ATP terminated 396 FVT episodes (89%), with an adjusted efficacy of 77% (95% CI 68% to 83%). VT acceleration caused by ATP occurred in 10 FVT episodes (4%). FVT arrhythmic syncope occurred on 9 occasions (2%) in 4 patients.

CONCLUSIONS

FVT (CL<320 ms) is common in ICD patients. ATP can terminate 3 of 4 of these episodes with a low incidence of acceleration and syncope. ATP for FVT may safely reduce the morbidity of painful shocks.

The British version of the Childhood Health Assessment Questionnaire (CHAQ) and the Child Health Questionnaire (CHQ)

We report herein the results of the cross-cultural adaptation and validation into the British language of the parent's version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children independently from the underlying disease. A total of 440 subjects were enrolled: 219 patients with JIA (17% systemic onset, 41% polyarticular onset, 33% extended oligoarticular subtype, and 9% persistent oligoarticular subtype) and 221 healthy children. The CHAQ clinically discriminated between healthy subjects and JIA patients, with the systemic, polyarticular and extended oligoarticular subtypes having a higher degree of disability, pain, and a lower overall well-being when compared to their healthy peers. Also the CHQ clinically discriminated between healthy subjects and JIA patients, with the systemic onset, polyarticular onset and extended oligoarticular subtypes having a lower physical and psychosocial well-being when compared to their healthy peers. In conclusion the British version of the CHAQ-CHQ is a reliable, and valid tool for the functional, physical and psychosocial assessment of children with JIA.

Titin as a chromosomal protein

We identified titin as a chromosomal protein using a human autoimmune scleroderma serum. We cloned the corresponding gene in the fruitfly, Drosophila melanogaster. We have demonstrated that titin is not only expressed and localized in striated muscle but is also distributed uniformly on condensed mitotic chromosomes using multiple antibodies directed against different domains of both Drosophila and vertebrate titin. Titin is a giant sarcomeric protein responsible for the elasticity of striated muscle. Titin may also function as a molecular scaffold during myofibril assembly. We hypothesize that titin is a component of chromosomes that may function to determine chromosome structure and provide elasticity, playing a role similar to that proposed for titin in muscle. We have identified mutations in Drosophila Titin (D-Titin) and are characterizing phenotypes in muscle and chromosomes.

Ion-dipole S(N)2 reaction in acetone-water mixtures. Electrostatic and specific solute-solvent interactions

The rate constants of the S(N)2 reaction of sodium 4-nitrophenoxide (1) and iodomethane were determined by UV-visible spectrophotometry in acetone-water mixtures at 25, 30, and 35 degrees C. The rate-Xwater (mole fraction of water) profile shows that the reaction depends strongly on the medium. The fastest rate constant was obtained in pure acetone, and a minimum occurred at Xwater= 0.4, whereas the observed second-order rate constants increases again in the water-rich region. In pure acetone, in the presence of dicyclohexano-[18]-crown-6, increases linearly with the concentration of the crown ether as a result of the complexation of the sodium ion (KS = 104.8 M) of the ion-pair and the increase in the effective concentration of free 4-nitrophenoxide ion, which was assumed to be the only reactive species. Ion-pairing was also detected at Xwater= 0.65 with a dissociation constant Kd = 7.82 x 10(-4) M(-1). The solvatochromic behaviors of 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)-1-phenoxide (2), 4-[(1-methyl-4(1H)-pyridinylidene)ethylidene]-2,5-cyclohexadien-1-one (3), and 1-methyl-8-oxy-quinolinium betaine (4) were investigated in the entire range of acetone-water mixtures. The dyes presented an increasing order of hydrophilicity compatible with their chemical structure, i.e., 2 < 3 < 4. Kinetic parameters for the methylation of 1 and the ET values of the dyes show a linear correlation of the polarity in the region of Xwater = 1.0-0.40 for 3 and 4, and it was observed that the more hydrophilic the dye the better the correlation coefficient, because of the structural similarity with 1. The activation parameter-Xwater profile shows extrema at Xwater < 0.4, reflecting an important change in the structure of the solvent that is responsible for the changes in the solvation of the reactive species including ion-pairs. These results suggest that the addition of water to acetone reduces abruptly the rate of substitution due to the preferential solvation (PS) of the phenoxide ion by the hydrogen-bonding donor (HBD) solvent. Nevertheless, the real second-order rate constant is "masked" by the association involving Na+ and 4-nitrophenoxide that extends even to water-rich mixtures. A model, based on the assumption that the free-energy terms involved in the second-order rate constant and the dissociation constant of the ion-pair have two components, is invoked to explain the kinetic data. One of the components depends on electrostatic interactions for which the main variable is the dielectric constant of the solvent mixture, and the other depends on the specific solute-solvent interactions, expressed by the activity coefficients of transfer of the species involved. The model indicates that in the range of Xwater = 1.0-0.40 the interactions are exclusively electrostatic, while for the rest of the acetone-rich region they are specific with a large contribution of the 4-nitrophenoxide ion.

[Tentorium cerebellum fistula. Diagnosis and treatment]

Among the 17 intracranial dural fistulae treated in the Department of Neuroradiology of the University Hospital of Coimbra (17 patients, 28 embolizations) between 19/10/98 and 20/11/2000, 4 cases (23%) were located on the tentorium cerebelli. Three patients were men aged 45, 53 and 56 years old. The remaining patient was an 85-year-old woman. All 4 patients were treated by embolization. One underwent post embolization surgical interruption of the draining vein. The authors analyse clinical presentation, complementary tests, therapy and outcome.

D-Titin: a giant protein with dual roles in chromosomes and muscles

Previously, we reported that chromosomes contain a giant filamentous protein, which we identified as titin, a component of muscle sarcomeres. Here, we report the sequence of the entire titin gene in Drosophila melanogaster, D-Titin, and show that it encodes a two-megadalton protein with significant colinear homology to the NH(2)-terminal half of vertebrate titin. Mutations in D-Titin cause chromosome undercondensation, chromosome breakage, loss of diploidy, and premature sister chromatid separation. Additionally, D-Titin mutants have defects in myoblast fusion and muscle organization. The phenotypes of the D-Titin mutants suggest parallel roles for titin in both muscle and chromosome structure and elasticity, and provide new insight into chromosome structure.

Thrombus formation at the site of radiofrequency catheter ablation

A 55-year-old woman with a history of resected atrial myxoma with residual patched atrial septal defect (ASD) underwent a successful radiofrequency (RF) ablation of reentry atrial tachycardia. She presented with progressive dyspnea 5 days later. Transesophageal echocardiography revealed a 1-cm right atrial mass attached to the intraatrial septum at the ablation site. Repeat study after anticoagulation for 5 weeks showed complete resolution of the thrombus. Thrombus formation at the site of RF ablation is a potential complication that may require aggressive anticoagulation. Patients with patched ASD might be at higher risk.

Consciousness as a definition of death: its appeal and complexity

A new formulation of death proposed in this study is based on the basic physiopathological mechanisms of consciousness generation in human beings. Two physiological components control conscious behavior: arousal and awareness (content of consciousness). We cannot simply differentiate and locate arousal as a function of the ascending reticular activating system and awareness as a function of the cerebral cortex. Substantial interconnections among the brainstem, subcortical structures and the neocortex, are essential for subserving and integrating both components of human consciousness. Therefore, consciousness does not bear a simple one-to-one relationship with higher or lower brain structures, because the physical substratum for consciousness is based on anatomy and physiology throughout the brain. This new account of human death is based on the irreversible loss of consciousness because it provides the key human attributes and the highest level of control in the hierarchy of integrating functions within the organism. The notion of consciousness as the ultimate integrative function is more consistent with the biologically-based systems than the more philosophically-based notions of personhood.

[Subclinical attention changes in transient ischemic attacks in the vertebrobasilar region]

INTRODUCTION

A significant number of patients who have had cerebrovascular illness apparently recover their former abilities completely but return to normal life with subtle cognitive deficits which may affect their daily lives. Such is the situation of patients with transitory ischemic accidents who present with sustained, undiagnosed attention deficits.

OBJECTIVES

To identify subclinical alterations due to attention deficits in patients with transitory ischemic accidents, and to contribute to the study of the physiopathological mechanisms involved in the integration of this function.

PATIENTS AND METHODS

We examined 44 persons, divided into three groups for this study: one group had vertebro-basilar transitory ischemic accidents, a second group had supratentorial infarct and a third was healthy. All were given a specially designed computerized test of continuous work to evaluate the sustained attention component.

RESULTS

Significant differences were found between the transitory ischemic accidents and healthy groups, regarding the variables including correct answers, omissions and indications of attention. This was not seen with the variables involving reaction time and number of errors. This demonstrated the existence of attention disorders involving omission in the group of patients with transitory ischemic accidents.

CONCLUSION

These findings suggest the hypothesis that in the vertebro-basilar region there are important mechanisms involved in the process of sustained attention.

[Neuro-cognitive condition of 8 year old children with congenital hypothyroidism treated early]

INTRODUCTION

Congenital hypothyroidism is the most important cause of preventable mental retardation. Since the use of programmes for early detection, mental retardation due to cretinism has been abolished and current investigations seek to detect subtle damage due to foetal hypothyroidism and strategies to minimize such deficits.

OBJECTIVE

This study presents the results of neurocognitive assessment of a group of 19 children aged 8 in the Cuban Programme for the early detection of Congenital Hypothyroidism.

PATIENTS AND METHODS

The programme is based on the use of umbilical cord serum levels of thyrotropin (TSH), using the Elisa ultramicro method (SUMA) and substitutive treatment with sodium levothyroxine and a programme of neuropsychiatric stimulation until 5 years old.

RESULTS

The results showed that the intelligence quotients of children with hypothyroidism were not statistically different from paired controls, and thus demonstrate the efficacy of the programme. On evaluation using computerized techniques for the detection of subtle disorders of the maintenance of attention, deficiencies were found. Analysis of the conventional EEG showed that in 13 cases recordings were normal, 4 had generalized cortical damage, 1 had cortico-subcortical damage and the remainder had signs of focal irritation. On the quantitative EEG, correlation between the attention variables and absolute values (MV2/Hz) were calculated for each derivation and associations found mainly in the right parietal and left frontal regions.

CONCLUSION

The effect of stimulating development in these patients is discussed.

[Physiologic role of the somatotrophic GH-IGF and others hormones in the domestic animals growth. Influence of the nutritional status]

In this review main hormones involved in development and muscle growth are shown with special emphasis on growth hormone (GH) and insulin-like growth factors (IGF). Chemist composition, synthesis place, action way and main action mechanisms of these hormones are reviewed. Nutritional factors which modified seric metabolites, and their effects on hormone secretion are detailed. It was observed that GH, IGF, thyroid hormones, insulin, glucocorticoids and sexual steroids act in a complex and cordinated way to produce a productive response to different> nutritional strategies.