Tachycardia''s toll: tachycardia induced cardiomyopathy — a case study

Cardiac arrhythmias are a well known cause of mortality for patients with heart disease. However, sinus tachycardia is a more unusual arrhythmia which can lead to serious heart damage or death. Even young patients with structurally normal hearts may become gravely ill.

This case study outlines the condition of sinus tachycardia, and associated changes in heart function, altered cellular structure of the myocardium and compensatory mechanisms in the body. Treatment modalities, including electro-physiological studies and drug therapies to moderate the tachycardia and myocardial oxygen demand of the heart, are discussed. Fourteen year old ‘Ben’ was previously a well, active and outgoing youth who suddenly became critically ill. He endured weeks of hospitalisation, numerous serious complications including Torsade de pointes arrhythmia, Cheyne-Stokes respirations, nausea and dizziness during this acute phase. Despite challenges, Ben's severely compromised heart muscle recovered at a remarkable rate.     

Clinical quiz. Rubinstein-Taybi syndrome (synonyms: broad thumbs and great toes, characteristic facies, and mental retardation -- broad thumb-hallux syndrome).

A 28-year-old mentally retarded, institutionalised woman was referred to us for evaluation of multiple plantar warts and ingrown nails of both great toes. The patient was born to unrelated parents of North African origin and had one brother and three half-brothers, all of whom were healthy. Physical examination revealed short stature, slight obesity, facial abnormalities (Fig. 1), short and broad thumbs and big toes (Figs. 2 and 3). A keloid was found on the right forearm, that had developed after surgical correction of a fracture (Fig. 4). Ill-defined hyperpigmented macules were observed on the trunk. The patient also presented pruritic eczematous lesions of the limbs and the back that had been present for some years and were recurrent despite treatment with emollients and local steroids. Androgenetic-type alopecia of moderate severity was seen on the vertex of the scalp. Past medical history included polydactylism of the feet and clinodactyly of the thumbs (both corrected surgically), respiratory tract infections, Wolf-Parkinson-White syndrome and refractive errors necessitating glasses.     

Neuronal projections to the medial preoptic area of the sheep,with special reference to monoaminergic afferents: Immunohistochemical and retrograde tract tracing studies

The preoptic area contains most of the luteinizing hormone releasing hormone immunoreactive neurons and numerous monoaminergic afferents whose cell origins are unknown in sheep. Using tract tracing methods with a specific retrograde fluorescent tracer, fluorogold, we examined the cells of origin of afferents to the medial preoptic area in sheep. Among the retrogradely labeled neurons, immunohistochemistry for tyrosine hydroxylase, dopamine-β-hydroxylase, phenylethanolamine N-methyltransferase, and serotonin was used to characterize catecholamine and serotonin fluorogold labeled neurons. Most of the afferents came from the ipsilateral side to the injection site. It was observed that the medial preoptic area received major inputs from the diagonal band of Broca, the lateral septum, the thalamic paraventricular nucleus, the lateral hypothalamus, the area dorsolateral to the third ventricle, the perimamillary area, the amygdala, and the ventral part of the hippocampus. Other numerous, scattered, retrogradely labeled neurons were observed in the ventral part of the preoptic area, the vascular organ of the lamina terminalis, the ventromedial part of the hypothalamus, the periventricular area, the area lateral to the interpeduncular nucleus, and the dorsal vagal complex. Noradrenergic afferents came from the complex of the locus coeruleus (A6/A7 groups) and from the ventro-lateral medulla (group A1). However, dopaminergic and adrenergic neuronal groups retrogradely labeled with fluorogold were not observed. Serotoninergic fluorogold labeled neurons belonged to the medial raphe nucleus (B8, B5) and to the serotoninergic group situated lateral to the interpeduncular nucleus (S4). In the light of these anatomical data we hypothesize that these afferents have a role in the regulation of several functions of the preoptic area, particularly those related to reproduction. Accordingly these afferents could be involved in the control of luteinizing hormone releasing hormone (LHRH) pulsatility or of preovulatory LHRH surge.     

AIDS education in Switzerland: implementing strategies to reach groups with high risk behaviours, particularly youth

In Switzerland the Federal Office of Public Health has developeda comprehensive set of AIDS care and prevention policies andactivities in recent years. For their actual implementation,the main responsibility lies with the health departments ofthe 26 Cantons. This paper originates from one of the largeCantons, Vaud. Major efforts have been made from the Federallevel to transmit relevant AIDS-related information to the generalpublic. Much remains to be done to assist people, especiallyhigh risk groups, to translate the vital prevention messagesinto behaviour changes. For youth in general, new attitudestowards sexual relations are called for, different from thoseof young people 10 or 15 years ago. In Vaud, a number of entrypoints are used to pass on this education: physicians and nursesinvolved in school health, teachers and, among the latter, twogroups with specific in-service training and part-time functions—mediators(who make themselves available to children in various risk situations)and health animators (promoting the inclusion of health educationtopics in the teaching). There is a special health programmefor 16–19 year olds. Also a substantial tradition of sexualeducation sessions in the school system offers valuable opportunitiesfor AIDS education. Further, innovative strategies are developedto reach and work with the male homosexuals and, to the extentpossible, intravenous drug addicts. In conclusion it is emphasizedthat, in many ways, AIDS education issues demand courage fromhealth and public leaders.     

Bone Density in Survivors of Childhood Cancer

Advances in combination chemotherapy, radiation therapy, surgery, and bone marrow transplantation have resulted in markedly improved survival rates for many children with cancer. Advancements in therapy, however, have led to new concerns, namely long-term consequences of effective treatments. Young adult and adult survivors of childhood cancer are at risk for a number of disorders related to therapy. Specifically, the young adult who has survived cancer, attendant treatments, and their complications is at risk for factors that can lead to suboptimal acquisition of peak bone mass. These factors include chronic illness, nutritional deficiencies, limited physical activity, and treatment with glucocorticoids, multiagent chemotherapy, and radiation. The long-term adverse effects of these therapies on endocrine systems, especially sex steroid and growth hormone deficiencies, are additional risk factors for some patients. After a brief review of the processes associated with acquisition of peak bone mass in the young adult, this article examines the impact of cancer and cancer therapy on bone mineral density in survivors of childhood cancer.     

Enzyme immunoassay of histamine in foods

A competitive enzyme immunoassay of histamine in foodstuffs has been developed using a monoclonal antibody against a histamine‐benzoquinone adduct. In this assay, histamine present in food samples was treated with 1,4‐benzoquinone to form histamine‐benzoquinone by a simple and quick reaction and a histamine‐benzoquinone‐horse‐radish peroxidase conjugate was used as the labelled hapten. The apparent association constant (K_a) of the antibody used was 3.6 ×10⁶ l/mol and Gibbs’ energy of the immune complex formation has been estimated to find the optimal incubation time of the assay. The method enabled determination of histamine in fish, cheese, wine and beer at a concentration as low as 7 ng/ml with an accuracy of ± 15%. The recovery of the immunoassay was 88.9–114%. Cross‐reactivities of histidine, tyramine, tryptamine and its derivatives were lower than 0.001% and did not affect the assay.     

Glutamic acid decarboxylase-like immunoreactivity in brainstem auditory nuclei of the rat

The distribution of GABA-producing neurons in the brainstem auditory nuclei of the rat was investigated immunohistochemically by using an antibody to glutamic acid decarboxylase (GAD). In the cochlear nuclei, GAD immunoreactive neurons are present only in the superficial granular and molecular layers, whereas terminals are found in all subdivisions of the nuclei and are particularly dense surrounding large spherical cells and one type of stellate cell. In the superior olivary complex, GAD immunoreactive neurons are located in the lateral olivary nucleus and throughout the periolivary region. Immunoreactive terminals are distributed along dendrites of principal cells of the medial and lateral olivary nuclei and are clustered around somata of globular neurons of the nucleus of the trapezoid body. An extremely dense band of immunoreactive somata and terminals is present along the ventral edge of the olivary complex. The ventral, intermediate, and dorsal nuclei of the lateral lemniscus contain small fusiform GAD-immunoreactive neurons and a moderately dense plexus of immunoreactive terminals. The inferior colliculus contains a large population of GAD-immunoreactive perikarya and an extremely dense accumulation of immunoreactive terminals in the central, dorsomedial, and external nuclei. These observations indicate that GABA systems are involved in function at all levels of the brainstem auditory pathway.     

Lack of correlation between ex vivo apical dye penetration and presence of apical radiolucencies.

OBJECTIVE: The aim of this study was to determine if there is a significant correlation between the in vivo presence of periapical radiolucency and ex vivo apical dye penetration on the same human teeth. STUDY DESIGN: Eighty-four endodontically filled teeth that were scheduled for extraction were classified into 2 groups according to the presence or absence of a periapical radiolucency and further divided into 2 subgroups according to the quality of the root canal filling. After extraction, the apical filling was evaluated by a dye penetration method. RESULTS: The dye extraction evaluation showed no correlation between apical dye penetration and the presence of a periapical radiolucency (not significant), but a statistically significant correlation with the quality of the root canal filling (P = .03). CONCLUSION: The results of the dye penetration study were correlated to the quality of the root canal filling but had no predictive value for the development of periapical radiolucency.