New Diagnostic Finding to Assess Para-Hisian Pacing Observed in a Patient with a Permanent Form of Junctional Reciprocating Tachycardia

Morphologic Change During Para-Hisian Pacing. Para-Hisian pacing, a useful method to differentiate conduction over an accessory pathway from conduction over the AV node, is assessed essentially by comparing the timing of local atrial electrograms between Hisbundle captured heats and His-bundle noncaptured heats. We describe the case of a patient with a permanent form of junctional reciprocating tachycardia, in whom an atrial double potential was recorded only during the tachycardia at the right posterior septum. During para-Hisian pacing, a morphologic change in the atrial electrogram at the posterior septum was also identified, as well as a change in the retrograde atrial sequence. Since the morphologic change of atrial electrograms during para-Hisian pacing cannot be demonstrated in a patient without an accessory pathway, this new finding could he considered a new additional diagnostic criterion suggesting the presence of an accessory pathway.     

Serum N-acetylglucosaminyltransferase III activities in hepatocellular carcinoma

N-Acetylglucosaminyltransferase III (GnT III) catalyses the addition of N-acetylglucosamine through a β 1–4 linkage to the mannose of the trimannosyl core, resulting in conversion of the concanavalin A (Con A)-reactive glycan into a non-reactive state. In this study, we measured GnT III activity to evaluate its diagnostic efficacy and its therapeutic effect on hepatocellular carcinoma (HCC). Concanavalin A-non-reactive fraction of serum transferrin (Tf) was also determined since the sugar chains of Tf are one of the possible candidates for the product of GnT III. Serum samples (159) were used from patients with HCC (89), liver cirrhosis (30), chronic hepatitis (19), alpha-fetoprotein (AFP) producing gastric carcinoma metastatic to the liver (five) and healthy controls (16). N-Acetyl-glucosaminyltransferase III activity was determined by high performance liquid chromatography. The reactivity of serum Tf to Con A was also analysed in 21 paired HCC samples before and after treatment by crossed immuno-affinoelectrophoresis. N-Acetylglucosaminyltransferase III activity from the HCC group (153 ± 72 pmol/mL/h) was significantly higher than that from liver cirrhosis (99 ± 67 pmol/mL per h), chronic hepatitis (84 ± 39pmol/mL per h) and the normal controls (62 ± 16pmol/mL per h). N-Acetylgiucosaminyltransferase III activity of 21 patients with HCC was significantly reduced after treatment such as transcatheter arterial chemoembolization and/or percutaneous ethanol infection therapy, (123 ± 77 to 100 ± 60pmol/mL per h). Commensurate decreases of AFP and des-γ-carboxy prothrombin with GnT III activity were also observed after treatment. The Con A-non-reactive fraction (n= 21; 6.4 ± 2.3%) in patients with HCC after treatment was significantly lower than before (8.2 ± 2.4%). The present study suggests that GnT III activity is a possible and in the diagnosis and evaluation of HCC, especially when other tumour markers are negative.     

EFFECTS OF A FEMINIZING TESTICULAR LEYDIG CELL TUMOUR ON NONTUMOROUS TESTICULAR TISSUE: AN ULTRASTRUCTURAL STUDY

The ultrastructural effects of a Leydig cell tumour of the testis on nontumorous testicular tissue have not yet been reported. Described here are the electron microscopic findings in the nonneoplastic testicular tissue of a patient with a feminizing testicular Leydig cell neoplasm. Serial studies were carried out over a period of 3 1/2 years prior to removal of the tumour. The overall general picture was characterized by progressive degeneration of Leydig cells, cells of the germinal series and Sertoli cells. Concomitantly, there was increasing thickening and fibrosis of the tubular walls. Cytoplasmic focal accumulations of glycogen, increasing with the duration of the disease, were conspicuous in many spermatogonia. All of these alterations are nonspecific and are attributable to adverse endocrine effects introduced by the oestrogen-secreting tumour. They were present bilaterally and were more prominent on the tumour-bearing side. Attention is drawn to the role of artifacts, fixation technique and degenerative processes in the production and appearance of certain ultrastructural findings, such as ‘light’ and ‘dark’ cells, myelin figures, membranous whorls and focal glycogen accumulations.     

HPLC-studies on nonmercapt-mercapt conversion of human serum albumin

Human mercaptalbumin (HMA) and nonmercaptalbumin (HNA) could be separated by high-performance liquid chromatography (HPLC) at neutral pH. Using HPLC, the present authors found the nonmercapt-mercapt conversion (HNA ← HMA) during hemodialysis and the mercapt-nonmercapt conversion (HMA ← HNA) after hemodialysis in chronic renal failure, indicating HMA as the covalent carrier protein for sulfur-containing amino acids.     

Validity of positron emission tomography using fluoro-2-deoxyglucose for the preoperative evaluation of endometrial cancer

To clarify the validity of positron emission tomography using fluoro-2-deoxyglucose (FDG-PET) for the preoperative evaluation of endometrial cancer, we analyzed the preoperative FDG-PET images of both primary and metastatic lesions of 30 patients with endometrial cancer, and compared them with computed tomography (CT) and/or magnetic resonance imaging (MRI) images and the results of postoperative pathologic findings. As to the primary lesions, FDG-PET could easily identify the cancer, and the sensitivity was 96.7%, which tended to be higher than that of 83.3% by CT/MRI. As to the evaluation of retroperitoneal lymph node metastasis, FDG-PET could detect none of five cases of lymph node metastatic lesions of up to 0.6 cm in diameter but had higher specificity (100%) compared with CT/MRI (85.7%). The sensitivity of FDG-PET for detection of extrauterine lesions excluding retroperitoneal lymph nodes was 83.3% and was superior to that of CT/MRI (66.7%), although there was no difference in the specificity between the modalities (100%). The diagnostic ability of FDG-PET was limited if used alone, but FDG-PET gave additional information especially with regard to the extrauterine lesions whose significance could not be determined on CT/MRI. However, we also found that FDG-PET could not identify any lymph node metastasis less than 1 cm in diameter; therefore, a negative finding of lymph node metastasis on FDG-PET should not be interpreted as a reason for omitting retroperitoneal lymph node dissection for the precise surgical staging of endometrial cancer.     

Current Density Distribution by Ring and Diagonally Arranged Half‐Ring Electrodes in Bipolar and Overlapping Biphasic Impulse Stimulation

Background: We have studied the acute and long‐term efficacy of overlapping biphasic impulse (OLBI) stimulation for atrial pacing with VDD pacemakers and demonstrated the feasibility of DDD pacing in OLBI with diagonally arranged half‐ring (Half‐Ring) electrodes. We made two three‐dimensional computational analysis models to verify our clinical studies. Methods and Results: Model I was composed of a heart, a pacemaker, and a human body. Model II was a cube with dimensions of 20 by 20 by 20 mm quarried from Model I for the detailed study of current density distributions. Laplace's equation was solved using the finite element method and the current density J was calculated. For Model I, the distal and proximal voltages were ?10 V, 0 V in bipolar and ?5 V, +5 V in OLBI, using Ring electrodes. In Model II, the actual measurements of electrode impedances obtained from the clinical study (1,180 Ω for Ring and 630 Ω for Half‐Ring) were added to the analysis conditions. Model I showed that OLBI produced more concentrated current density distributions than those by bipolar. According to Model II, at the atrial myocardium position current density produced by Half‐Ring was larger than that by Ring electrodes, 70 μA/mm² versus 30 μA/mm² in OLBI configuration. It also indicated that even if electrode impedances were equal between Half‐Ring and Ring electrodes, the maximum current density produced by Half‐Ring would be greater than that by Ring electrodes. Conclusions: It was considered that OLBI configuration with Half‐Ring electrodes provides more effective current density distributions. (PACE 2010; 33:1063–1073)     

Synthesis and central nervous system actions of thyrotropin-releasing hormone analogs containing a 1-substituted 2-oxoimadazolidine moiety*

A series of thyrotropin-releasing hormone (TRH) analogs in which the pyroglutamic acid residue was replaced by (S)-2-oxoimidazolidine-4-carboxylic acid (Oic-OH) and the related derivatives was prepared, and the central nervous system (CNS) actions were examined. Of these, 1-benzyl-Oic-His-Pro-NH₂ (2c) showed the most potent activities, which were 1.5-8 times greater than those of TRH. Moreover, the thyrotropin (TSH)-releasing activity of 2c was about 1/16 times weaker than that of TRH.     

1H-n.m.r. studies on cross-relaxation phenomena in bovine mercaptalbumin (BMA) solution and partially hydrolyzed bovine plasma albumin (BPA*) gel

Bovine plasma albumin Fr. V(BPA) contains small amounts of proteolytic enzyme which catalyzes a very limited cleavage of BPA in the F-form near pH 3.8, resulting in the formation of partially hydrolyzed BPA(BPA*). BPA* had a tendency to form a transparent gel at pD 4.0 (pD range of the F-form) above 7%. Highly purified proteolytic enzyme-free bovine mercaptalbumin (BMA) was in a transparent solution at pD 4.0 even at 12.4%. after 5 days incubation at 35°. Cross-relaxation times (T_IS) between irradiated protein protons and observed protons, such as side chain and water protons, were studied on BMA solution and BPA*-gel. T_IS values of BMA solution, obtained by the saturation transfer (SATUR) and inversion recovery (INVER) methods, were a single kind of T_IS for each side chain. Those of BPA*-gel by the SATUR method indicated the presence of two kinds of T_IS, that is, short and long T_IS values for each side chain. However, those by the INVER method showed a single kind of T_IS for each side chain, corresponding to the long T_IS value by the SATUR method. The short T_IS values of BPA*-gel, observed by the SATUR method, may be due to immobile joint parts of fibrous BPA* aggregates. T_IS values from protein to water protons (T_IS(HDO)) in BPA*-gel, obtained by the INVER method, were far shorter than those in BMA solution, indicating a large amount of hydration of BPA* and rapid exchange between bound and bulk water in the gel state.