Evaluation of diseased coronary arterial branches by polar representations of thallium-201 rotational myocardial imaging

The perfusion territories in polar representations of stress Tl-201 rotational myocardial imaging in patients with angina pectoris who had one diseased coronary segment were analyzed. The lesions proximal or distal to the first major septal perforator in left anterior descending arteries were detected by the presence or absence of defects at the base of the anterior septum. Right coronary artery lesions were detected by the presence of defects at the basal posterior septum, in contrast to the preservation of myocardial uptake at this portion in lesions of the left circumflex artery. The specific defect patterns were detected in cases with lesions at the first diagonal, obtuse marginal, and posterolateral branches. Recognition of these defects in the polar maps allows detailed detection of diseased coronary arterial branches.     

Correlation between scalp-recorded electroencephalographic and electrocorticographic activities during ictal period.

OBJECTIVE: To investigate the correlation between scalp-recorded electroencephalographic (EEG) and electrocorticographic (ECoG) activities during ictal periods. METHODS: Simultaneous EEG and ECoG recordings with chronic subdural electrodes were performed in eight patients with partial epilepsy. RESULTS: In two cases where the ictal ECoG discharges originated in deep brain structures such as the hippocampus and interhemispheric surface of the frontal lobe, ictal discharges could not be detected on EEG until they expanded to the cortex of convexity. In four cases, the ictal onset zones were located in the lateral convexity. When synchronous or near synchronous ictal ECoG discharges with amplitudes of 200-2000muV were recorded on more than 8-15cm(2) of cortex, corresponding discharges were recorded on EEG in these four cases. However, in a case of frontal lobe epilepsy, asynchronous ictal ECoG discharges were recorded on 10 electrodes of convexity but no ictal EEG activity was recorded. Furthermore, in two frontal lobe epilepsy cases, ictal EEG discharges did not always reflect the ictal ECoG spike, but occasionally reflected slow background ECoG activity around the ictal discharges. CONCLUSIONS: Multiple factors such as the width of the cortical area involved, amplitude of ictal discharges and degree of synchronization of electrical potentials play important roles in the appearance of ictal EEG recordings, and the relationship between ictal EEG and ECoG is not straightforward.     

Distinct osteogenic mechanisms of bones of distinct origins

Mammalian bones have three distinct origins (paraxial mesoderm, lateral plate mesoderm, and neural crest) and undergo two different modes of formation (intra-membranous and endochondral). Bones derived from the paraxial mesoderm and lateral plate mesoderm mainly form through the endochondral process. During this process, hypertrophic chondrocytes play a vital role in inducing both osteogenesis and angiogenesis. One of the essential osteogenic factors secreted from hypertrophic chondrocytes is Indian hedgehog (Ihh). In contrast, bones derived from the neural crest mainly form through the intramembranous pro-cess and do not require Ihh. Thus, depending on their origin, bones have distinct signaling properties, which need to be considered in the research and application of bone biology.Presented at the 18th Annual Research Meeting of the Japanese Orthopaedic Association, Kitakyushu, Japan, October 17, 2003     

Chemically induced forestomach papillomas in transgenic mice carry mutant human c-Ha-ras transgenes.

Forestomach papillomas and skin papillomas were induced very efficiently by a single dose administration of the chemical carcinogen methylnitrosourea (MNU) in transgenic mice (rasH2 line) carrying human hybrid c-Ha-ras genes, which encode the prototype p21 gene product. The incidence of forestomach papillomas was dose dependent; when 50 mg/kg of MNU were administered i.p., all of the transgenic mice (56 of 56) developed forestomach papillomas within 12 weeks after administration, whereas 5 and 0.5 mg/kg of MNU induced papillomas in 2 of 19 and 1 of 19 mice, respectively. Nine of 56 transgenic mice (16%) also developed skin papillomas at sites wounded by bites or scratches. Only 1 of 77 nontransgenic littermates developed forestomach papillomas after administration of 50 mg/kg of MNU, and no skin papillomas appeared within 12 weeks after MNU administration. The transgenes (integrated copy number, 5-6) in the tumors developed in 55 of 56 affected transgenic mice (98%) contained at least 1 copy of the transgene that was activated by somatic point mutation at the 12th codon, from GGC (Gly) to GAC (Asp). Because somatic point mutations at the 12th or 61st codon of transgenes have never been detected in normal tissues of transgenic mice thus far examined, these mutational activations of transgenes are tumor-specific events. RNA expression of these activated transgenes was also detected. From these results, it is suggested that somatic mutational activation of the human c-Ha-ras transgene plays a causative role in the occurrence of forestomach and skin papillomas induced by MNU administration in these transgenic mice. This transgenic mouse provides a unique screening system for chemicals that induce or suppress papillomagenesis.     

Autoradiographic Analysis of Radiolabeled Anti-carcinoembryonic Antigen Monoclonal Antibody CEA102 in Colorectal Cancer Using Computed Radiography

Anti-carcinoembryonic antigen monoclonal antibody (MAb) CEA102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with ¹³¹I-labeled intact CEA102 or its F(ab')₂. Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of ¹³¹I-labeled CEA102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the distribution of administered radiolabeled MAb in individual tumors, but the density of the tumors was higher than that of the normal tissues. In the quantitative distribution analysis of CEA102, the uptake of the primary tumor (mean 1.10%ID/kg) was ten-fold greater than that of the normal colon mucosa (mean G.10%ID/kg). These results revealed that the application of MAb has great potential in radioimmunodetection as well as in antibody-directed therapy.     

beta-Hydroxybutyrate fuels synaptic function during development. Histological and physiological evidence in rat hippocampal slices.

To determine whether ketone bodies sustain neuronal function as energy substrates, we examined the effects of beta-hydroxybutyrate (betaHB) on synaptic transmission and morphological integrity during glucose deprivation in rat hippocampal slices. After the depression of excitatory postsynaptic potentials (EPSPs) by 60 min of glucose deprivation, administration of 0.5-10 mM D-betaHB restored EPSPs in slices from postnatal day (PND) 15 rats but not in slices from PND 30 or 120 rats. At PND 15, adding D-betaHB to the media allowed robust long-term potentiation of EPSPs triggered by high frequency stimulation, and prevented the EPSP-spike facilitation that suggests hyperexcitability of neurons. Even after PND 15,D-betaHB blocked morphological changes produced by either glucose deprivation or glycolytic inhibition. These results indicate that D-betaHB is not only able to substitute for glucose as an energy substrate but is also able to preserve neuronal integrity and stability, particularly during early development.     

The sequential evaluation of bone scintigraphy: an analysis of revascularised bone grafts

Technetium-99m Methylene Diphosphonate (Tc-99m MDP) has often been used to assess revascularisation of bone, because positive uptake of Tc-99m MDP reflects patent anastomoses and viability of the grafted bone. However, the sequential evaluation of bone scintigraphy has seldom been reported, especially in clinical cases. We carried out sequential evaluation in 17 patients with revascularised bone grafts. In this series, intense or maximal uptake in the grafted bone was observed in the early days after surgery (1-2 weeks postoperatively), with considerable reduction after 4 weeks. Furthermore, it was found that there was no uptake of Tc-99m MDP when the anastomosed vessels were occluded, even after 6 weeks, and these three cases all developed fracture or sequestrum. We therefore believe that bone scintigraphy is reliable in the postoperative monitoring of revascularised bone for at least 4 or 6 weeks postoperatively.     

Surgical Treatment of Intractable Seizures Due to Hypothalamic Hamartoma

Summary: A 6.5-year-old boy developed seizures at age 2.8 years consisting of episodes of unconsciousness and laughing attacks. By age 6 years, multiple seizure types, including generalized tonic-clonic (GTC), complex partial (CPS) and akinetic seizures, and drop attacks were occurring several times daily. EEG showed multifocal epileptic discharges. Antiepileptic drugs (AEDs) did not control the seizures. With progression of the epilepsy, cognitive deterioration developed. There were no manifestations of precocious puberty. Neuroimaging disclosed a suprasellar mass in continuity with the hypothalamus, and a diagnosis of hypothalamic hamartoma was made. After surgical resection of the hamartoma, the seizures were completely alleviated, and the epileptic EEG discharges disappeared. Improvement of mental function was also noted.     

Abdominal vagotomy attenuates interleukin-1β-induced nitric oxide release in the paraventricular nucleus region in conscious rats

Nitric oxide (NO) has recently been shown to modulate the hypothalamic–pituitary–adrenal axis response to interleukin-1β (IL-1β). We measured levels of nitrite (NO₂⁻) and nitrate (NO₃⁻) in the hypothalamic paraventricular nucleus (PVN) region using an in vivo brain microdialysis technique in conscious rats. Intraperitoneally administered IL-1β produced a significant increase in both NO₂⁻ and NO₃⁻ levels in the PVN region. We also examined the possible involvement of the abdominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sham-operated rats. Our results suggest that the abdominal vagal afferent nerves are involved in intraperitoneally administered IL-1β-induced NO release in the PVN region.     

A patient with hepatic granuloma formation and angiotensin-converting enzyme production by granuloma cells during clinical relapse of hepatitis A

Elevation of the serum angiotensin-converting enzyme (sACE) level and hepatic granulomas were found during a clinical relapse in a 22 year old patient with acute viral hepatitis type A (AVH-A). The serum transaminase level and sACE level remained high for more than 6 months. In the biopsied specimen of the liver, fibrous rings of granulomas composed of collagen types I, III, and V were observed. Furthermore, the localization of ACE was visible in the rough endoplasmic reticulum of epithelioid cells of granulomas in the liver under electron microscopy using the indirect immunoperoxidase method. These results suggest that granuloma cells in the liver caused by hepatitis A may be involved in ACE production. In addition, other diseases associated with the presence of granulomas in the liver, such as lymphoma, cytomegalovirus infection, visceral leishmaniasis, and lupoid hepatitis, were ruled out. However, the hepatic granulomas disappeared with the healing of AVH-A. In this regard, the present case is considered to be one of the very few cases of hepatic sarcoidosis.