Tc-99m tetrofosmin myocardial perfusion SPECT after dipyridamole combined with low-level exercise in the diagnosis of coronary artery disease

Tc-99m tetrofosmin is a lipophilic, cationic perfusion imaging agent that changes to Tl-201 in detecting coronary artery disease during exercise testing. The purpose of this study is to evaluate the usefulness of Tc-99m tetrofosmin dipyridamole stress imaging combined with low level exercise for the detection of coronary artery disease. We examined 42 patients and 10 normal volunteers who also underwent coronary angiography. A one-day protocol was used: in the stress study, 296 MBq of tetrofosmin was injected and in the rest study 888 MBq was injected. After intravenous administration of dipyridamole (0.142 mg/kg/min for 4 minutes), the patient was exercised on a bicycle ergometer for 3 min (25 Watts). Tetrofosmin was injected 2 minutes after dipyridamole infusion during the exercise. Single photon emission computed tomographic images were obtained 30 minutes after the tracer injection. Images were interpreted as abnormal in 36 of 42 patients with coronary artery disease, and normal in all of 10 normal volunteers. The overall sensitivity of detection of coronary artery disease was 83.3% and the normalcy rate was 100%. The diagnostic values for the detection of significant stenosis in the three major arteries were: LAD sensitivity 83%, specificity 92%; LCX sensitivity 47%, specificity 91%; RCA sensitivity 75%, specificity 83%. Of the 66 arteries with more than 50% stenosis, 48 arteries were correctly identified. Of the 36 with more than 70% stenosis, 31 were identified. Scintigraphic evidence of multivessel disease was found in only 9 patients (50%). A protocol of Tc-99m tetrofosmin SPECT combined with low level exercise after dipyridamole is therefore useful for the detection of the coronary artery disease.     

Mechanisms underlying the enhanced elevation of IL-1beta and TNF-alpha mRNA levels following endotoxin challenge in rat alveolar macrophages cultured with low-Mg2+ medium.

We have previously shown that interleukin (IL)-1beta and tumour necrosis factor (TNF)-alpha mRNA levels in rat alveolar macrophages are increased in by endotoxin (lipopolysaccharide; LPS)- stimulation and further enhanced by culturing with low-Mg2+ medium. We have now investigated the mechanisms of underlying this enhancement by using some specific signal transduction inhibitors. The enhanced elevation of both mRNAs levels was suppressed by pretreatment with TMB-8 (which inhibits calcium release from the endoplasmic reticulum) or dexamethasone (which inhibits nuclear factor [NF]-kappaB and activator protein [AP]-1), but not with verapamil or nifedipine (which inhibits calcium channels). The enhancment of IL-1beta, but not TNF-alpha mRNA levels, was suppressed by pretreatment with W-7 (which inhibits calmodulin), whereas the enhancement of TNF-alpha mRNA levels was suppressed by pretreatment with U73122 (which inhibits phospholipase C). Curcumin (an inhibitor of AP-1), suppressed the increases in both mRNAs induced by low-Mg2+ medium alone, but had no suppressive effect on the levels of either mRNA after LPS-stimulation in low-Mg2+ medium. Pyrrolidine dithiocarbamate (an inhibitor of NF-kappaB) prevented the elevation of TNF-alpha mRNA levels induced by low-Mg2+ medium without LPS-stimulation, but had no suppressive effect on IL-1beta mRNA levels. From these results, we conclude that the enhanced elevation of IL-1beta and TNF-alpha mRNA levels seen in LPS-stimulated alveolar macrophages in low-Mg2+ medium occurs partly via the same, and partly via different, signaling pathways.     

Myasthenia gravis and steroid therapy]

In the past 20 years, we experienced 242 myasthenic patients in our hospital. Fifty five cases were administered high doses of adrenocorticosteroid hormone for a long time. Among them, we analysed 39 cases with complete clinical records from admission to the present. We analysed 5 additional cases in whom responses to the therapy somewhat unique in that four cases have not shown any improvement until the drug was reduced to certain dosages, and in the 5th case change of method from alternate-day to every day brought good recovery of the symptoms. As a result, adrenocorticosteroid hormone was effective for 100% of the patients in this series. However, complete remission appeared in the above mentioned 10 patients (26%), after 2-3 years' continuous administration. Prognosis was far better in those who showed shorter durations between the onset of the disease and thymectomy or thymectomy than in those of longer one. In these cases, the maximum daily doses were 60-100 mg in alternate-day administration, and the total amount of prednisolone was 9-15 g in individual cases. Through data of these cases, it is recommended that the maximum dosage is to be continued for as long as 2 to 19 weeks with average 7 weeks.     

Assessment of skull base involvement of nasopharyngeal carcinoma by bone SPECT using three detectors system]

SPECT of the skull was performed on twelve patients with histologically proven nasopharyngeal carcinoma using newly developed three detectors SPECT system (Toshiba GCA 9300A) mounted with fan-beam collimators, for the purpose of early detection of skull base involvement of the disease. This SPECT system has extremely improved resolution with FWHM of 8 mm in the center, and it provides clear tomographic images of the skull which has anatomically complex structure. SPECT image was taken 3 hours after injection of 740 MBq (20 mCi) of 99mTc-MDP following whole body skeletal survey. In twelve patients with confirmed nasopharyngeal carcinoma, 8 patients showed positive findings on SPECT. Three of SPECT positive patients also showed destructive findings on CT. Other five positive patients did not show destructive findings on CT at their initial examinations, but in three of them CT findings turned to positive later. SPECT was superior to CT in early detection of skull base involvement. We believe that SPECT of the skull is a diagnostic tool for early detection of skull base involvement of nasopharyngeal carcinoma.     

Postoperative infection with methicillin-resistant Staphylococcus aureus and its control measures in patients with esophageal cancer--prediction of high risk patients]

Whether or not compromised host defense prior to surgical treatment is related to development of infection with methicillin-resistant staphylococcus aureus (MRSA) following major surgery was examined. Of 22 patients undergoing esophagectomy for cancer between 1989 and 1990, 5 were free from MRSA colonization and infection (group I) while 8 had MRSA colonization without infection (group II) and 9 had MRSA infection (group III). Levels of neutrophil cytocidal functions, complements, immunoglobulins and cell-mediated immunity were not significantly different among these three groups. The mean of anti pneumococcal polysaccharide (PPS)-IgG was significantly lower in group III than in group I (p < 0.05) and tended to be lower than in group II (P = 0.08). All infected patients showed a titer < 600 EU while all but one non-infected patient did so > 600 EU. Serum IgG2 levels positively correlated with anti-PSS IgG levels. Thus, we concluded that a preoperative evaluation of antibody response against polysaccharides and serum IgG2 levels can serve to predict development of MRSA-related infection following esophageal surgery.     

Evaluation of image-diagnosing methods of enlarged parathyroid glands in chronic renal failure

Three noninvasive image-diagnosing methods, computed tomography (CT), scintigraphy with²⁰¹T1C1 and^99mTcO_h4 ^–, and ultrasonography (US), were preoperatively performed on 50 patients with chronic renal failure and secondary hyperparathyroidism who underwent total parathyroidectomy and parathyroid autograft. The detection rates of the 3 methods on the 191 excised parathyroid glands were compared according to weight and location. CT detected 57.1% of all glands and 78.6% of 103 glands weighing over 500 mg. Scintigraphy detected 51.8% and 75.7%, and US detected 42.4% and 53.4%, respectively. The detection rate of upper glands was best with CT at 58.9% and 89.1%; that of lower glands was best with scintigraphy at 65.3% and 80.4%. Although the combination of the 3 methods diagnosed 69.6% and 89.5%, CT and scintigraphy, the best 2 combinations, visualized 67.5% and 88.3%.

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Resumen Tres métodos diagnósticos no invasivos, la tomografía computadorizada (TC), la centelleografía con²⁰¹T1C1 y^99mTcO₄ y la ultrasonografía (US) fueron realizados preoperatoriamente en 50 pacientes con falla renal crónica e hiperparatiroidismo secundario sometidos a paratiroidectomía y autotransplante paratiroideo. Las tasas de detección de los 3 métodos fueron comparados sobre las 191 glándulas paratiroideas resecadas en relación a los pesos y a los sitios de ubicación. La TC detectó el 57.1% del total de glándulas y el 78.6% de aquellas glándulas (103) con pesos superiores a 500 mg. La centelleografía detectó 51.8% y 75.7%, y la US 42.4% y 53.4% respectivamente. La tasa de detección para las glándulas superiores fue optima con TC, con 58.9% y 89.1%; la de las glándulas inferiores fue óptima con centelleografía, con 65.3% y 80.4%. Aunque la combinación de los 3 metodos diagnosticó el 69.6% y 89.5%, la TC y la centelleografía, la mejor de las combinaciones, visualizó el 67.5% y el 88.3% respectivamente.

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Résumé Trois méthodes d'imagerie non invasives, la tomodensitométrie, la scintigraphie (avec T1C1²¹⁰ et TcO₄ ^99m), et l'ultrasonographie ont été pratiquées avant l'intervention chez 50 malades qui présentaient une insuffisance rénale chronique compliquée d'hyperparathyroïdisme secondaire et qui furent traités par parathyroïdectomie totale et autogreffe parathyroïdienne. Les taux de détection de ces 3 méthodes concernant 191 glandes parathyroïdes réséquées ont été évalués en fonction du poids et du siège des lésions. La tomodensitométrie a permis de découvrir 57.1% de toutes les glandes et 78.6% des glandes dont le poids dépassait 500 mg; la scintigraphie 51.8% et 75.7%; l'ultrasonographie 42.4% et 53.4%. Le taux de détection des glandes supérieures fut plus élevé avec la tomodensitométrie: 58.9% et 89.1%; celui des glandes inférieures le fut avec la scintigraphie: 65.3% et 80.4%. Si la combinaison des 3 méthodes permet le diagnostic dans 69.6% et 89.5% des cas la tomodensitométrie associée seulement à la scintigraphie donne des résultats très voisins, les taux respectifs étant de 67.5% et de 88.3%.

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Presented at the International Association of Endocrine Surgeons in Paris, September 1985.