Effect of relaxation training on cardiac parasympathetic tone

To examine the hypothesis that the relaxation response is associated with an increase in cardiac parasympathetic tone, the frequency components of heart rate variability during relaxation training were investigated in 16 college students. Electrocardiograms and pneumograms were recorded during a 5-min baseline period followed by three successive 5-min sessions of the autogenic training (relaxation) or by the same periods of quiet rest (control), while subjects breathed synchronously with a visual pacemaker (0.25 Hz). Although neither the magnitude nor the frequeney of respiration showed a significant difference between relaxation and control, the amplitude of the high-frequency component of heart rate variability increased only during relaxation (p= .008). There was no significant difference in the ratio of the low-frequency (0.04–0.15 Hz) to the high-frequency amplitudes. The increased high-frequency amplitude without changes in the respiratory parameters indicates enhanced cardiac parasympathetic tone. Thus, our results support the initial hypothesis of this study. Enhanced cardiac parasympathetic tone may explain an important mechanism underlying the beneficial effect of the relaxation response.     

Evaluation of a prostate biopsy strategy for cancer detection using a computer simulation system with virtual needle biopsy for three-dimensional prostate models

AIM: We evaluated a prostate biopsy strategy for cancer detection using a computer simulation system with virtual needle biopsy for three-dimensional (3D) prostate models. METHODS: Two 3D prostate models with a volume of 25 cc or 50 cc were constructed from computed tomographic images of radical prostatectomy specimens. The peripheral zone (PZ) and transition zone (TZ) were arranged in the prostate models according to the anatomical information. Four thousand patterns of cancer lesions were automatically inserted into each prostate model with a proportion of 75% in PZ and 25% in TZ. Average hit rates (AHR) in prostate models were evaluated both with an increased number of biopsy cores and various angles of virtual needle biopsy. The influence of adding secondary tumors for hit rates was also evaluated. RESULTS: For both sizes, the laterally angled biopsy in 4-8 core biopsy schemes showed higher AHR than the vertical plane biopsy, while the vertical plane biopsy in 10-18 core biopsy schemes showed higher AHR than the laterally angled biopsy. A higher number of biopsy cores increased the AHR of secondary tumors. CONCLUSIONS: Our results suggest that it is important in prostate cancer detection to change the needle placement according to the number of biopsy cores and the size of the prostate.     

Congenital leukaemia with a mixed phenotype of megakaryoblasts and erythroblasts: a case report and characterization of the blasts

We present a congenital leukaemia with a mixed phenotype of megakaryoblasts and erythroblasts. A newborn male with exopthalmus and multiple skin nodules, had bone marrow blasts which expressed CD41b, CD42b, glycophorin-A and haemoglobin, but monocyte or lymphoid markers were negative. The patient achieved a complete remission with chemotherapy. Blasts cultured for a few months expressed erythroid markers but lost the megakaryocytic phenotype, although addition of phorbol ester induced the latter phenotype. Spontaneous colony formation was observed in semi-solid culture and the number of colonies was increased by erythropoietin. Detailed studies further indicated the heterogeneity of congenital leukaemia.     

Exact Location of the Branching Bundle in the Living Heart

Aims: The His bundle electrogram is believed to reflect the exact location of the His bundle. However, the distinction between distal His bundle potential and proximal right bundle branch potential is challenging. The aim of this study was to pinpoint the location of the branching point of the His bundle, and to compare that site with the site of recording of the largest His bundle electrogram (LH) during sinus rhythm.
Methods: We hypothesized that the site of earliest His activation (EH) during retrograde conduction via the left bundle branch is the branching point. We studied 15 nonconsecutive patients (mean age = 40 ± 22 years; eight men). We performed a programmed stimulation from right ventricular apex until retrograde right bundle branch block appeared. At that point we measured (1) the distance between antegrade LH site and retrograde EH site and (2) the atrial-to-ventricular amplitude ratio (A/V ratio) at both sites.
Results: EH was recorded at the proximal electrode of the His bundle catheter in all patients. Mean distance between EH and LH was 9.8 ± 2.5 mm. The mean A/V ratios at the EH site and the LH site were 1.01 ± 0.42 and 0.08 ± 0.06, respectively.
Discussion: This study showed that the EH site is located approximately 10-mm proximal to the LH site. The mean A/V ratio at the EH site during sinus rhythm is approximately 1.0. These observations suggest that the majority of His potentials reflect proximal right bundle activation. Before delivering radiofrequency energy in the para-Hisian area, attention should be paid to the presence of a His potential and to the A/V ratio, rather to the amplitude of the His electrogram.     

Serum cholesterol levels in school-aged Japanese children: The Hisayama study

Hypercholesterolemia has been known to be an important factor in the development of atherosclelosis. Blood cholesterol screening and related health education in children, however, have not yet been widely practiced in Japan. From 1985 to 1990, blood samples were obtained from 5825 school children aged 6 to 14 years residing in Hisayama, Japan. The mean total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were determined. The mean TC levels ranged from 155 to 172 mg/dL for boys and from 156 to 170 mg/dL for girls, peaking at 9 years for both sexes. The TG levels also tended to increase gradually and to peak at 11 years for both sexes. The tendency for TG levels to be higher was much clearer than in US children and adolescents. The HDL-C levels were highest at 9 years of age for both sexes and the LDL-C levels also tended to peak at 9 years of age for boys and at 8 years of age for girls. Atherogenic Indices [(TC-HDL-C)/HDL-C] ranged from 1.7 to 1.9 for boys and 1.8 to 2.0 for girls. As the cholesterol level of Japanese children would be expected to rise steadily reflecting their westernized lifestyle, preventive programes on a nationwide base including health education at school environments should be emphasized.     

Anthracycline-induced cardiotoxicity in children with malignancies

The anthracyclines (ATC) have been used in the treatment of many pediatric patients with malignancies. Their use, however, has been limited by a serious and potentially irreversible cardiotoxicity. The medical records of pediatric patients with malignancies who received ATC at the Department of Pediatrics, Kyushu University, from January 1985 to December 1994 were reviewed. Among the 120 children with malignancies who received ATC, six patients (5%) developed congestive heart failure, 33 (28%) had subclinical cardiac dysfunction, whereas 81 (66%) showed no evidence of cardiac dysfunction. The incidence of ATC cardiotoxicity increased at higher cumulative doses. The earliest cardiotoxicity, however, was observed in a patient who received 180 mg/m² unassociated with other risk factors, showing the marked individual variations in its development. Children younger than 4 years had a higher incidence of cardiotoxicity compared with those older than 4 years (P < 0.01) and are therefore more vulnerable to ATC cardiotoxicity. Because serial myocardial biopsies and stress testing are not practical in younger children, and radionuclide angiogram is rather costly and not appropriate for frequent evaluation, non-invasive tests such as echocardiography and electrocardiography (ECG) still play the main role for serial cardiac monitoring in these age groups. Radionuclide angiogram should be added as the confirmatory test modality.     

Follow-up X Rays Play a Key Role in Detecting Implantable Cardioverter Defibrillator Lead Fracture:

MORISHIMA, I., et al .: Follow-up X Rays Play a Key Role in Detecting Implantable Cardioverter Defibrillator Lead Fracture: A Case of Incessant Inappropriate Shocks Due to Lead Fracture. A patient with an implantable cardioverter defibrillator (ICD) received incessant inappropriate shocks due to a lead fracture 3 years after implantation. Routine lead measurements at 3-month intervals had shown no abnormal findings even at the most recent measurement performed 2 months prior to the event. In contrast, serial observation of chest X rays clearly disclosed progressive lead narrowing starting 11 months prior to the event. This case indicates the importance of the routine chest X rays in long-term follow-up of ICDs and sets a precedent for interpreting lead narrowing in such X rays. (PACE 2003; 26[pt. I]:911–913)     

Biological activity of synthetic analogs of serum thymic factor*

A series of analogs of serum thymic factor (Facteur Thymique Sérique; FTS) devoid of C- and N-terminal few residues were synthesized and their ability to induce Thy-1 (θ) antigen in vitro on mouse T lymphocyte precursors was examined. The pentapeptide moiety (Lys-Ser-Gln-Gly-Gly) seems to be important for the expression of agonistic activity. Some of the short chain peptides showed antagonistic properties. Synergistic activation by two inactive analogs was observed.