Understanding cardiac arrhythmias

This review highlights the applied science intrinsic to the interpretation of the electrocardiogram and cardiac arrhythmias in children.     

Effects of cessation of a policy of neonatal fluconazole prophylaxis on fungal resurgence

Fluconazole has been used as prophylaxis against systemic fungal infections in preterm neonates. We conducted a study to determine whether cessation of a policy of prophylactic fluconazole results in a resurgence of fungal infections in a unit. Neonates born in the 3 epoches: A 36-month pre-Fluconazole prophylaxis epoch (Group 1), a 21-month Fluconazole prophylaxis epoch (Group 2) and a 39-month post Fluconazole prophylaxis epoch (Group 3) were compared for incidence and onset of fungal sepsis and resistance patterns. There was a decline in the incidence of fungal sepsis from Group 1 to Group 2, and it remained stable from Group 2 to Group 3. There was no significant difference in resistance to Fluconazole and to any of the azoles in Groups 1, 2 and 3 respectively.     

Alpha-thalassemia among tribal populations of Eastern India

Five hundred and thirteen unrelated subjects belonging to various tribes of West Bengal, Arunachal Pradesh and Assam in Eastern India, were screened for the presence of alpha-thalassemia (thal) gene deletion(s) as a possible cause of unexplained anemia (Hb < 11 g/dL and/or MCH <28 pg, MCV < 78 fL). As reported earlier, beta-globin gene mutant alleles were found with a frequency of up to 20% in some tribes. In the present study, alpha-globin gene deletion alleles were found in 18% of subjects from West Bengal, 3.9% from Arunachal Pradesh and 3.84% from Assam tribesmen. Coexistence of alpha- and beta-globin gene abnormalities was observed in up to 18% of some tribal groups. The high inbreeding rate and lack of appropriate medical care make these populations particularly vulnerable.     

Biochemical demonstration of mu-opioid receptor association with Gsalpha: enhancement following morphine exposure

Biochemical data indicate mu-opioid receptor (MOR) coupling predominantly to the G(i) and G(o) family. Additionally, MOR coupling to G(s) is suggested by pharmacological assessments that have revealed excitatory MOR effects, which are resistant to pertussis toxin and sensitive to cholera toxin. However, biochemical evidence for such interactions remains elusive; G(salpha) has not been shown to be present in immunoprecipitate obtained using anti-MOR antibodies. In the current study, the presence of MOR in immunoprecipitate obtained with anti-G(salpha ) antibodies was investigated using Chinese hamster ovary cells stably transfected with MOR (MOR-CHO). MOR Western analyses of opioid naive MOR-CHO membranes immunoprecipitated using anti-G(salpha) antibodies reveal the presence of an approximately 75-80 kDa MOR species. Interestingly, acute and chronic morphine treatment markedly enhances the magnitude of MOR that co-immunoprecipitates with G(salpha), despite the concomitant down-regulation of membrane MOR protein. Enhanced co-precipitation of MOR with G(salpha) occurs without a concomitant increase in the immunoprecipitated G(salpha) protein indicating their increased association. In contrast, chronic morphine diminishes the co-immunoprecipitation of MOR with G(ialpha). Moreover, although only a single MOR species co-immunoprecipitated with G(salpha), MOR Western analysis of MOR-CHO membranes as well as immunoprecipitate obtained with either anti-MOR or anti-G(ialpha) antibodies reveals the presence of multiple molecular mass species of MOR. These data reveal the existence of a subset of MORs whose association with G(salpha) can be enhanced by morphine exposure. Notably, the regulation by chronic morphine of MOR association with G(salpha) and G(ialpha) is reciprocal. The relevance of MOR-Gs(alpha) coupling to opioid tolerance formation is discussed.     

Pervasive developmental disorders in preschool children: confirmation of high prevalence

OBJECTIVE: The rate of reported pervasive developmental disorders has increased, and the authors found a rate of 62.6 per 10,000 in a previous study of preschoolers in Stafford, U.K. They conducted another survey in 2002 to estimate the prevalence in children in a later birth cohort and to compare it to previous findings from the same area. METHOD: Screening for developmental problems included 10,903 children ages 4.0 to 6.0 years who were living in a Midlands town on the survey date. Children with symptoms suggestive of pervasive developmental disorders were intensively assessed by a multidisciplinary team using standardized diagnostic interviews, psychometric tests, and medical workups. RESULTS: Sixty-four children (85.9% boys) were diagnosed with pervasive developmental disorders. The prevalence was 58.7 per 10,000, with a 95% confidence interval (CI) of 45.2-74.9, for all pervasive developmental disorders, 22.0 per 10,000 (95% CI=14.1-32.7) for autistic disorder, and 36.7 per 10,000 (95% CI=26.2-49.9) for other variants. These rates were not significantly different from the previous rates. The mean age at diagnosis was 37.8 months, and 53.1% of the children were originally referred by health visitors. Of the 64 children with pervasive developmental disorders, 29.8% had mental retardation, but this rate varied by disorder subtype. Few children had associated medical conditions. CONCLUSIONS: The rate of pervasive developmental disorders is higher than reported 15 years ago. The rate in this study is comparable to that in previous birth cohorts from the same area and surveyed with the same methods, suggesting a stable incidence.     

Oral itraconazole in treatment of candidemia in a pediatric intensive care unit

Objective: To examine efficacy of itraconazole in the treatment of candidemia in critically ill children.Methods: We studied retrospectively cases of candidemia seen consecutively in our Pediatric Intensive Care Unit (PICU) over three and half year.Candida isolates from those patients included.Candida albicans- 19, C.tropicalis-31,C. guillermondii- 9,C.krusei- 4 andC. glabrata-1Results: Of the 64 patients, 48 (75%) had symptoms suggestive of septicemia and 16 had no symptoms suggestive of septicemia. No antifungal therapy was given to asymptomatic patients; they recovered from candidemia without development of any sequelae. Of the 48 symptomatic patients 11 died before results of fungal culture became available and antifungal therapy could be started. Thirty seven patients were treated with itraconazole (10 mg/kg/day orally or through gastric tube). Seven (18.9 %) of 37 patients died, 3 within first week of antifungal therapy. Thirty (81%) patients recovered; microbiological cure was noted on average by day 14 (range 4–30 days). The mean ±SD duration of therapy in patients who responded was 24 ±7 days (range 21–42 days). None had any major side effect.Conclusion: We conclude that oral itraconazole may be effective in treatment of candidemia in children in a PICU where non-C.albicans Candida species constituted majority (70%) of allCandida isolates.     

The role of human endogenous retroviruses in trophoblast differentiation and placental development

A major portion of the human genome appears to be of retroviral origin. These endogenous retroviral elements are expressed in a variety of normal tissues and during disease states, such as autoimmune and malignant conditions. Recently, potential roles have been described for endogenous retroviral envelope proteins in normal differentiation of human villous cytotrophoblast into syncytiotrophoblast. This article provides a brief critical review of the current state of knowledge concerning the expression of the env regions of three endogenous retroviral elements: ERV-3, HERV-W, and HERV-FRD. A testable model of villous cytotrophoblast differentiation is constructed, in which a complementary expression of endogenous retroviral envelope proteins initiates hCG production, decreased cell proliferation, and intercellular fusion.     

Functional characterization of the pentapeptide QYNAD on rNav1.2 channels and its NMR structure

The endogenous pentapeptide QYNAD (Gln-Tyr-Asn-Ala-Asp) is present in human cerebrospinal fluid (CSF), and its concentration is increased in demyelinating diseases. QYNAD was synthesized and its action on the rNa_v1.2 voltage-gated sodium channel -subunit was studied using whole-cell recordings in a heterologous expression system. The effects were seen only upon equilibration of the peptide in the external bath solution for at least 10 min before the commencement of whole-cell experiments. The steady-state activation curve showed a rightward shift of 10 mV, while the steady-state inactivation curve showed a leftward shift of 5 mV. Frequency-dependent inhibition of the sodium current amplitude was observed at 2–10 Hz, in the presence of external QYNAD, but was not seen when applied internally. Fits of the whole-cell sodium current traces by Hodgkin-Huxley equations revealed subtle changes in the voltage-dependent rate constants governing the transition of the activation and the inactivation gates. Two dimensional NMR spectroscopy revealed the absence of medium and long-range Nuclear Overhauser effects (NOEs), which indicates that the peptide does not adopt any canonical secondary structure in solution. In summary, our studies show that although the pentapeptide QYNAD does not have a defined structure in solution, it has defined actions on the rNa_v1.2 voltage-gated sodium channel isoform.     

Psychosomatic illnesses in patients attending the medical outpatient department in a government hospital

The incidence of psychosomatic illness among Indian patients has been found to be high. Owing to the stigma attached to psychiatric illnesses, most patients remain reluctant to visit a psychiatrist. The result is an overcrowding in the medicine and other specialist departments. A psychiatry department with consultation-liaison psychiatric service in each government hospital is the need of the day.     

Why is squint surgery in children in decline?

BACKGROUND:/aims: Paediatric squint surgery appears to be declining. This study aims to identify if this is so and, if so, why. METHODS: Retrospective review of (1) episodes of paediatric squint surgery in Scotland and Tayside, 1986-2001, (2) presentations to orthoptists (Tayside) during 1986 and 1996. RESULTS: (1) Overall, a 58% fall in surgery in Scotland and 59% in Tayside. For esotropia, a reduction of 63% (Scotland) and 69% (Tayside). (2) Incidence of esotropia was unchanged; surgery for these esotropes fell (from 55% to 30%) (p = 0.013). More children received maximum hypermetropic correction (p <0.001) and more developed stereopsis (p = 0.003). CONCLUSION: Childhood strabismus surgery, particularly for esotropia, is declining. The maximum hypermetropic correction has improved the functional results.