Carcinoid Tumor of the Middle Ear Containing Serotonin and Multiple Peptide Hormones A Case Report and Review of the Pathology Literature

A 69-year old man complaining of longstanding hearing loss and mild otorrhea was found to have a mass obliterating the external auditory canal and polypous tympanic mucosa with accompanying absence of the tympanic membrane and ossicular chain. Tumors excised from the external auditory canal and tympanum showed histologic features essentially characteristic of a carcinoid tumor: a ribbon or festoon arrangement of tumor cells, formation of anastomosing cords and glandular spaces, presence of numerous argyrophilic as well as argentaffin secretory granules within many of the tumor cells, and ultrastructur-al evidence of neurosecretory granules in the tumor cell cytoplasm. Immunohistochemically, the tumor was found to contain not only neuronal marker substances such as neuron-specific enolase, S 100 protein and chromogranin A, but also serotonin and multiple peptide hormones such as pancreatic polypeptide, glucagon, cholecystokinin and leucine-enkephalin. A review of the pathology of 17 previous cases of carcinoid of the middle ear suggested that this type of carcinoid may have a variegated hormone profile among carcinoids of foregut origin, and hormonally may resemble ileal carcinoid arising from the midgut, although their histogenetic origins may differ, because of frequent production of serotonin. Acta Pathol Jpn 42: 614–620, 1992.     

Cell-type-specific excitatory and inhibitory circuits involving primary afferents in the substantia gelatinosa of the rat spinal dorsal horn in vitro

The substantia gelatinosa (SG) of the spinal dorsal horn shows significant morphological heterogeneity and receives primary afferent input predominantly from Aδ- and C-fibres. Despite numerous anatomical and physiological studies, correlation between morphology and functional connectivity, particularly in terms of inhibitory inputs, remains elusive. To compare excitatory and inhibitory synaptic inputs on individual SG neurones with morphology, we performed whole-cell recordings with Neurobiotin-filled-pipettes in horizontal slices from adult rat spinal cord with attached dorsal roots. Based on dendritic arborization patterns, four major cell types were confirmed: islet, central, radial and vertical cells. Dorsal root stimulation revealed that each class was associated with characteristic synaptic inputs. Islet and central cells had monosynaptic excitatory inputs exclusively from C-afferents. Islet cells received primary-afferent-evoked inhibitory inputs only from Aδ-fibres, while those of central cells were mediated by both Aδ- and C-fibres. In contrast, radial and vertical cells had monosynaptic excitatory inputs from both Aδ- and C-fibres and inhibitory inputs mediated by both fibre types. We further characterized the neurochemical nature of these inhibitory synaptic inputs. The majority of islet, central and vertical cells exhibited GABAergic inhibitory inputs, while almost all radial cells also possessed glycinergic inputs. The present study demonstrates that SG neurones have distinct patterns of excitatory and inhibitory inputs that are related to their morphology. The neurotransmitters responsible for inhibitory inputs to individual SG neurones are also characteristic for different morphological classes. These results make it possible to identify primary afferent circuits associated with particular types of SG neurone.     

Delayed image of iodine-123 iomazenil as a relative map of benzodiazepine receptor binding: The optimal scan time

Delayed single-photon emission tomograpic (SPET) images after an intravenous bolus injection of iodine-123 iomazenil have been used as a relative map of benzodiazepine receptor binding. We determined the optimal scan time for obtaining such a map and assessed the errors of the map. SPET and blood data from six healthy volunteers and five patients were used. A three-compartment kinetic model was employed in simulation studies and analyses of actual data. The simulation studies suggested that, in the normal brain, the scan time at which a single SPET image best represented the relative receptor binding was 3.0–3.5 h post-injection. This finding was supported by actual data from the volunteers. The simulation studies also suggested that the optimal scan time was not greatly changed by the variability of the input functions, and that the error in the SPET image contrast in the vicinity of the optimal scan time was not increased by changes in the tracer kinetics in the entire brain. The SPET image contrast in the patients at 3.0 h post-injection agreed well with the reference receptor binding estimated by kinetic analysis, with a mean error of 3.6%. These findings support the use of a single SPET image after bolus injection of [¹²³I]iomazenil as a relative map of benzodiazepine receptor binding. For this purpose, a SPET scan time of 3.0-3.5 h post-injection is recommended.     

Multivessel coronary revascularization with bilateral internal thoracic artery grafts

Sixteen patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts between 1988 and 1989 at the Okayama University Hospital. A total 39 coronary grafts were performed, being an average of 2.4 grafts per patient. Each patient received bilateral ITA grafts, and in 5 patients an additional 7 grafts were constructed with 5 autologous veins and 2 gastroepiloic arteries. The right ITA was grafted as a free graft in 4 patients. The ITA graft patency rate was 96.8 per cent (31/32) at the time of hospital discharge. The postoperative morbidity included one reoperation for bleeding and one myocardial infarction. Coronary artery bypass grafting with bilateral ITA grafts can be safely performed and its application facilitates complete revascularization with arterial grafts.     

Changes in bone turnover markers during 14-day 6° head-down bed rest

Osteoporosis caused by exposure to microgravity represents a serious clinical concern, but the mechanisms have yet to be fully elucidated. The present research aimed to elucidate the effects of microgravity environments on bone turnover, with a specific focus on changes in bone resorption markers such as type I collagen cross-linked N-telopeptides (NTx) and deoxypyridinoline (Dpyr), for which scant data are available regarding detailed time course. Methods using 6° head-down bed rest were utilized to simulate a microgravity environment. Eleven adult male volunteers underwent 6° head-down bed rest for 14 days; measurements were made of serum and urine Ca concentrations, in addition to osteocalcin (OC), bone alkaline phosphatase (ALP), NTx, and Dpyr as bone turnover markers. By the end of bed rest, concentrations of bone ALP had significantly increased, but OC displayed a tendency toward decrease. Concentrations of Dpyr significantly increased from day 6, remaining elevated until the end of bed rest. Concentrations of NTx significantly increased on day 13 and at the end of bed rest. Serum and urinary concentrations of Ca increased significantly at the end of bed rest. Bone ALP represents a relatively early marker of osteoblast differentiation at the matrix maturation phase and OC is a late marker in osteoblast differentiation at the calcification phase. The present results therefore suggest an absolute increase in bone resorption and normal or reduced bone formation, together causing prominent uncoupling and rapid bone loss after simulated microgravity. Moreover, the present results suggest that bone resorption is enhanced at an early stage of exposure to microgravity environments.     

Patient absorbed dose in coronary angiography determined by the flat panel digital detector X-ray system

The INNOVA 2000, an all-digital cardiovascular X-ray system with flat panel detector, is equipped with a monitoring function that makes it possible to track a patient's absorbed dose by displaying the real-time presumed absorbed dose. We verified this dose monitoring system and evaluated how it is affected by various parameters. We also compared the INNOVA 2000 to a conventional machine, the Advantx LC. The average absorbed dose of the INNOVA 2000 was 1,066 mGy, while that of the Advantx LC was calculated to be 2,028 mGy. Dose reduction with the INNOVA 2000 was 76% at Low mode and 52% even at Normal mode. The INNOVA provides an advantage in lowering absorbed dose, even considering that it has a rectangular image intensifier (I.I.) versus the Advantx LC's round I.I. This comparison was made by cine and digital angiography.     

Direct synaptic contacts of catecholamine axons on the preganglionic sympathetic neurons in the rat thoracic spinal cord

Preganglionic sympathetic neurons were labelled by retrograde transport of horseradish peroxidase, while catecholamine axon varicosities were marked by the uptake of 5-hydroxydopamine in the intermediolateral nucleus of the rat. The direct synaptic contacts from the catecholamine axons to the preganglionic sympathetic neurons were demonstrated. Catecholamine axons formed symmetric synapses.     

An autopsy case of pulmonary and central nervous system metastatic osteosarcoma treated with thirty-six courses of chemotherapy over four years]

A 32-year-old man presented with cough, dyspnea and orthopnea ten years after amputation of the right humerus because of osteosarcoma. Chest radiographs and chest computed tomographs showed left pleural effusion, pericardial effusion and a giant intrathoracic mass, which was histologically diagnosed as a recurrence of the osteosarcoma. After 4 courses of chemotherapy combined with CDDP, the mass in the left upper lobe of the lung decreased in size, and it was then resected. Three months later, new metastatic lesions were detected in the thoracic area. Therefore, 29 additional courses of chemotherapy were administered (36 courses in total over 4 years; including regimens combined with CDDP, carboplatin, high-dose methotrexate, ifosfamide, dacarbazine, vindesine, etoposide, vincristine, taxotere and gemcitabine). In spite of the several courses of chemotherapy, brain and spinal cord metastases appeared, and the patient eventually died of cerebral hemorrhage. During the four years after the first recurrence he had good quality of life as a result of the chemotherapy.     

The Benefits of High‐flow Management in Children With Pulmonary Atresia

The high‐flow management of cardiopulmonary bypass (CPB; ≥2.4 L/min/m²) is a standard strategy used at this institute for children with pulmonary atresia (PA) due to a fear that the blood flow may be diverted by the major/minor aortopulmonary‐collateral‐arteries and hypervascularization due to long‐term hypoxia. The purpose of this study was to describe the validity of high‐flow management in children with PA. The CPB records of 23 children with PA who underwent a definitive biventricular repair between Feb 2006 and Nov 2008 were retrospectively reviewed. The mean age at the operation was 33 ± 22 months. The blood‐pressure during bypass was controlled with the same protocol. The mean cooling‐temperature was 28.4 ± 3.7°C. The mean minimum hematocrit was 25.0 ± 3.4%. The mean maximum bypass flow index at the initiation, the mean maximum flow index during aortic cross‐clamping, the mean minimum flow index during aortic cross‐clamping, and the mean maximum flow index after rewarming were 3.1 ± 0.5, 3.1 ± 0.5, 2.6 ± 0.4, and 3.2 ± 0.4 L/min/m², respectively. The higher bypass flow indexes significantly correlated with the lower serum lactate levels. The lowest oxygen delivery during CPB had significant influences on the urine output during bypass (R = 0.547, P = 0.007), the serum lactate levels at the end of CPB (R = ?0.442, P = 0.035), and the postoperative thoracic effusion (R = ?0.459, P = 0.028). A bypass flow index of 2.4 L/min/m² may not be sufficient and the maximum requirement of bypass flow index may be 3.2 L/min/m² or more in this patient population.