Koch's Triangle Sized Up: Anatomical Landmarks in Perspective of Catheter Ablation Procedures

Koch's triangle contains the compact part of the atrioventricular node and is anatomically delineated by the Eustachian ridge, the membranous septum, and the insertion of the tricuspid valve. In-feriorly, Koch's triangle ends at the site of the OS of the coronary sinus and, in part, is continuous with the sub-Eustachian pouch. Catheter ablation procedures for several types of reentrant tachycardias are based on identifying these anatomical landmarks. Variability in the dimensions of Koch's triangle thus may be clinically relevant. We examined 50 hearts. Anatomical landmarks measured were the Eustachian ridge, the tricuspid valve, the overall length between the membranous septum and the coronary sinus, the width of the coronary sinus, the Eustachian ridge in its roof and the distance to the tricuspid valve, and that of the sub-Eustachian pouch. Individual variations were marked. The mean values (± SD) were: Eustachian ridge 29.4 ± 5.3 mm. tricuspid valve 28.9 ± 4.5 mm, coronary sinus 10.8 ± 2.2 mm, Eustachian ridge 3.7 ± 2.3 mm, space underneath coronary sinus 8.6 ± 3.4 mm, and sub-Eustachian pouch 26.8 ± 3.3 mm. The overall length varied between 15 and 38 mm, with a mean of 26.3 ± 4.5. In conclusion, Koch's triangle shows considerable individual variations in size. Given the fact that the absolute figures for the range in size of the compact atrioventricular node is much less than that of Koch's triangle, these variations have implications for catheter ablation procedures.     

Papillary cystadenocarcinoma of the prostate

A giant cystic formation was found behind the prostate of a 69-year-old man who presented with urinary retention. Ultrasonography, computed tomography scans and magnetic resonance imaging revealed a large cystic intrapelvic mass and biopsy of the cyst wall diagnosed papillary cyst adenocarcinoma. Immunohistochemically, the tumor originated from the prostate.     

Night-time hypnopompic visual hallucinations related to REM sleep disorder

Abstract We encountered three patients who had experienced hypnopompic visual night-time hallucinations. Their clinical manifestations resembled Charles Bonnet's syndrome and the content of their experiences were understood as attempts at wish fulfillment. However, abnormal REM findings were recognized on polysomnogram at the occurrence of visual hallucination in two cases. We speculated that dysfunction of REM sleep mechanism might contribute to the night-time occurrence of such kind of visual hallucination and that their visual experiences might be reflected by dream content.     

The pH Measurement of Fasting Gastric Juice in Acute Gastric Mucosal Lesions

Abstract: Fasting gastric juice acidity was assessed to elucidate its role in the cause of acute gastric mucosal lesions (AGML). Gastric juice was aspirated through an auxiliary endoscopic channel during routine endoscopic examinations, and its pH was measured with a glass electrode PH meter. The pH of 100 cases with AGML (acute hemorrhagic erosions (AHE), acute gastric ulcer and acute hemorrhagic gastritis), and 586 cases with other ulcerative or inflammatory lesions were compared with the gastric juice pH in 1775 endoscopically normal subjects. The pH value was classgied into four acid groups: Hyperacidity (pH < 1.4), Normoacidity (1).5 < pH < 2.0), Hypoacidity (2).1 < pH <4.0) and Anacidity (4). 1 < pH). In cases with AHE, a signifcant hyperacidity was recognized both in the periods preceding and just after the onset. This hyperacidity was followed by signgicant anacidity, and thereafter a return to normoacidity. These pH changes coincided well with endoscopic appearances; preceding stage-hypernormacidity, black-slough stage—hyperacidity, white-slough stage-anacidity and scarring stage-;normoacidity. These results suggest that an elevation of gastric acidity etiologically relates with the formation of AGML, especially Shin.     

Testicular Toxicity of Gallium Arsenide, Indium Arsenide, and Arsenic Oxide in Rats by Repetitive Intratracheal Instillation

The testicular toxicities of two compound semiconductor materials,gallium arsenide (GaAs) and indium arsenide (InAs), and arsenicoxide (As₂O₃) were examined in rats by repetitive intratrachealinstillation of these substances in suspension twice a week,a total of 16 times. A single instillation dose was 7.7 mg/kgin the GaAs and the InAs groups and 1.3 mg/kg in the As₂O₃ group.A significant decrease in sperm count and significant increasein the proportion of morphologically abnormal sperm were foundin the epididymis in the GaAs group. Especially, abnormal spermwith a straight head increased markedly in this group. In theGaAs–treated rats, there was 40-fold increase in the degeneratinglate elongated spermatids at the postspermiation stages, stagesIX, XI, and XI. From these results, it is indicated that GaAsdisturbed the spermatid head transformation at the late spermiogenicphases and caused spermiation failure. InAs caused a sperm countdecrease in the epididymis, though its testicular toxicity wasrelatively weak compared with that of GaAs. As₂O₃, a probabledissolution arsenic product of GaAs and InAs in vivo, did notshow any testicular toxicities in this study. It seems likelythat, along with arsenics, gallium and indium play a role inthe testicular toxicities of GaAs and InAs.     

Contraction and relaxation in the absence of a sarcoplasmic reticulum: muscle fibres in the small pelagic tunicate Doliolum

Previous ultrastructural observations suggested thatDoliolum muscle fibres apparently lacked both sarcoplasmicreticulum and transverse tubular-system. External Ca2+ isrequired for contraction, caffeine does not evoke contraction,nor does it increase intracellular Ca2+ level. Ryanodine at 50m has no effect on electrically-evoked contractions.Further, electrical stimulation in external solutions lacking Na+leads to sustained contracture. We conclude that intracellularCa2+ stores are absent in these rapid obliquely-striated fibres,and that reduction in internal Ca2+ levels following contractiondepends upon Na+-Ca2+ exchange across the sarcolemma     

Biochemical Changes in Rat Erythrocytes Caused by Ethylene Oxide Exposure

Biochemical Changes in Rat Erythrocytes Caused by Ethylene OxideExposure. MORI, K., INOUE, N., FUJISHIRO, K., KIKUCHI, M., ANDCHIBA S. (1990). Fundam. Appl. Toxicol. 15, 441–447. WhenWistar male rats were exposed to ethylene oxide (EtO) at a concentrationof about 500 ppm, 6 hr a day, 3 days a week for 2, 6, or 13weeks, hematological examination showed macrocytic, normochromicanemia with a high reticulocyte count This result raised thepossibility that the hemolytic process was responsible for theanemia. Thus, the following possible causes of hemolysis wereinvestigated with erythrocytes obtained from control and EtO-exposedrats. (1) Metabolism in erythrocytes; (a) Hexose monophosphatecycle: The activity of glucose-6-phosphate dehydrogenase, 6-phosphogluconatedehydrogenase, or glutathione perox-idase was not affected,but the activity of glutathione reductase (GR) significantlydecreased and did not recover by the addition of flavin adeninedinucleotide. Reduced glutathione content also decreased andthe glutathione stability test was positive, (b) Embden-Meyerhofpathway: Adenosine triphosphate content did not decrease, (c)Lapoport-Luebering cycle: 2,3-Diphos-phoglycerate content wasnot affected. (2) Membrane alterations: Osmotic fragility wasnot affected and the activity of acetylcholine esterase in theghost membranes of the exposed group increased. (3) Hemoglobinstability: The heat test and the isopropanol test were negative.GR has an important function in maintaining the reducing powerin erythrocytes, and the decrease in the activity caused byEtO induced an alteration of the glutathione stability. Althoughthe mechanism of EtO-induced anemia could not be clearly explained,the inhibition of GR activity might be related to the anemia.     

Inhibition of Rat Acute Inflammatory Paw Oedema by Dihemiphthalate of Glycyrrhetinic Acid Derivatives: Comparison with Glycyrrhetinic Acid

Abstract— The anti-inflammatory profile of dihemiphthalate compounds of glycyrrhetinic acid derivatives in acute rat paw oedema induced by various vasoactive agents was compared with the parent compound. Three dihemiphthalate compounds (the di-sodium salt of 18 β-olean-12-ene-3β,30-diol di-O-hemiphthalate, 18β-olean-9(11),12-dione-3β,30-diol di-O-hemiphthalate and olean-11,13(18)-diene-3β,30-diol di-O-hemiphthalate), significantly inhibited development of carrageenan-induced rat paw oedema during the first 3 h (ED50 70, 90, and 108 mg kg^?1 respectively, p.o.), while glycyrrhetinic acid (ED50, 200 mg kg^?1) showed a significant inhibition of paw oedema 3 h after carrageenan treatment. The dihemiphthalate compounds also suppressed mouse paw oedema induced by histamine, bradykinin, and PAF acether at doses of less than 100 mg kg^?1. However, these compounds failed to inhibit 5-HT-induced mouse paw oedema. Glycyrrhetinic acid had little effect on mouse paw inflammation induced by the above irritants. The three compounds at 10^?7-10^?4 m , inhibited histamine-induced contraction of guinea-pig isolated ileum. However, concentration-response curves to 5-HT and bradykinin were not affected by the same compounds. These results suggest that the dihemiphthalate compounds modulate vascular permeability caused by endogenous vasoactive agents as one of the anti-inflammatory mechanisms. This action is quite different from that of glycyrrhetinic acid.     

Results of Prospective Cohort Study on Symptomatic Cerebrovascular Occlusive Disease Showing Mild Hemodynamic Compromise [Japanese Extracranial-Intracranial Bypass Trial (JET)-2 Study]

The purpose of this study is to determine the true threshold of cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) for subsequent ischemic stroke without extracranial-intracranial (EC-IC) bypass surgery in patients with hemodynamic ischemia due to symptomatic major cerebral arterial occlusive diseases. Patients were categorized based on rest CBF and CVR into four subgroups as follows: Group A, 80% < CBF < 90% and CVR < 10%; Group B, CBF < 80% and 10% < CVR < 20%; Group C, 80% < CBF < 90% and 10% < CVR < 20%; and Group D, CBF < 90% and 20% < CVR < 30%. Patients were followed up for 2 years under best medical treatment by the stroke neurologists. Primary and secondary end points were defined as all adverse events and ipsilateral stroke recurrence respectively. A total of 132 patients were enrolled. All adverse events were observed in 9 patients (3.5%/year) and ipsilateral stroke recurrence was observed only in 2 patients (0.8%/year). There was no significant difference among the four subgroups in terms of the rate of both primary and secondary end points. Compared with the medical arm of the Japanese EC-IC bypass trial (JET) study including patients with CBF < 80% and CVR < 10% as a historical control, the incidence of ipsilateral stroke recurrence was significantly lower in the present study. Patients with symptomatic major cerebral arterial occlusive diseases and mild hemodynamic compromise have a good prognosis under medical treatment. EC-IC bypass surgery is unlikely to benefit patients with CBF > 80% or CVR > 10%.