Simplified quantification of regional cerebral blood flow with99mTc-ECD SPECT and continuous arterial blood sampling

The goal of this study was to develop a simple method for quantification of regional cerebral blood flow (rCBF) with^99mTc-ethyl cysteinate dinier (ECD) SPECT. Following an intravenous constant infusion of ECD for one minute, serial dynamic SPECT imaging was performed for 40 minutes in 6 healthy male volunteers with intermittent arterial blood sampling. PET scan with¹⁵O-water was performed on the same day before the SPECT study for measurement of rCBF. Arterial blood data demonstrated rapid conversion of ECD to the hydrophilic metabolites, and most of the arterial input to the brain was completed within 5 minutes after the injection. Brain activity reached a peak value soon after the cessation of infusion, and was stable thereafter with very little washout. Net extraction of ECD in the brain calculated by arterial input of ECD and rCBF demonstrated a rapid decrease within a few minutes, reaching 42.7% at 5 minutes. The simulation study suggested that the arterial blood activity obtained by continuous drawing for 5 minutes and a single SPECT scan would provide a reasonable estimate of rCBF under the assumption of constant net extraction in the brain.     

Endoscopic US and Dynamic CT in Preoperative TN Staging of Esophageal Squamous Cell Carcinoma

Abstract: 〈Objective〉 The aim of this study was to assess the accuracy and limitations of endoscopic ultrasonography (US) and dynamic computed tomography (CT) in the preoperative evaluation of esophageal carcinoma. 〈Methods〉 Endoscopic US and dynamic CT were performed preoperatively in 96 patients with an esophageal squamous cell carcinoma. The results were correlated with the histology of specimens resected from patients who had undergone subtotal esophagectomy with lymph node dissection. 〈Results〉 According to the TN staging classification, endoscopic US was superior to dynamic CT for evaluating the depth of tumor infiltration (overall accuracy: EUS 75%, CT 35%) and in assessing regional lymph node metastases (overall accuracy: EUS 77%, CT 67%). However, the T4 stage was not accurately evaluated using endoscopic US in this study. Its specificity was high (97%) but its sensitivity was low (45%). 〈Conclusions〉 We believe endoscopic US is the most accurate method for local tumor staging in esophageal carcinoma. A limitation to endoscopic US staging performed with current instruments was severe stenosis, as it would not permit passage of the instrument (25% of all cases in this study).     

Lipiodol retention and massive necrosis after lipiodol-chemoembolization of hepatocellular carcinoma: Correlation between computed tomography and histopathology

This retrospective study examined the computed tomography (CT) criteria for judging the effectiveness of transcatheter arterial Lipiodolchemoembolization (Lp-chemo-TAE) in 35 cases with hepatocellular carcinoma (HCC). Massive necrosis, defined as involving 97% or more of the HCC nodule, was observed in 15 cases after Lp-chemo-TAE, whereas nonmassive necrosis, defined as involving ≤96% of the HCC nodule, was observed in the remaining 20 cases. In 12 of 15 cases (80%) with massive necrosis, uniform dense retention of Lipiodol (Lp) was observed throughout the HCC nodule on CT images 3–4 weeks after Lp-chemo-TAE as opposed to only one (5%) of 20 cases with nonmassive necrosis (p<0.01). Eight of nine cases (89%) with massive necrosis had tumor attentuation values of 365 Hounsfield units (HU) or greater on CT images 3–4 weeks after embolization, as opposed to only four (27%) of 15 cases with nonmassive necrosis (p<0.01). We conclude that the effectiveness of the Lp-chemo-TAE can be judged on CT from the degree and duration of Lp retention in the HCC nodule and the measurement of the attenuation value of the HCC nodule.     

Cochlear ototoxicity of chlorhexidine gluconate in cats

Summary Chlorhexidine gluconate is a derivative of chlorhexidine and is a popular desinfectant with a strong bactericidal action that is widely used for preoperative sterilization in ear surgery. The purpose of this investigation is to ascertain the potential ototoxity of this agent. After topically applying chlorhexidine gluconate solutions to the middle ear cavities of 12 cats, we observed the excised cochleas using both scanning and transmission electron microscope studies. Either 0.05% or 2% chlorhexidine gluconate solutions were infused into the right ear of the test animal through one of two tubes chronically installed in the tympanic bullae. The left ears were utilized as controls and were infused with sterilized physiological saline. The solutions were administered once every other day for three separate infusions. Nine animals were decapitated 7 days after the third application, while the other three animals were sacrificed at 4 weeks. In the 2% chlorhexidine group, we found that hair cells in the organ of Corti had degenerated and had lost their hair bundles over a wide range. This pathology was more marked in the lower cochlear turns. In the animals sacrificed at 4 weeks, the injuries present seemed to have progressed. Even at a clinical concentration of 0.05%, chlorhexidine caused intracellular degeneration but with little surface damage. Our findings would suggest a cause of hearing loss when chlorhexidine is used clinically in the ear.     

PANCREATIC CARCINOMA IN CHILDHOOD: Report of an Autopsy Case and a Review of the Literature

Clinical and histological findings of pancreatic carcinoma in a 6-year-old boy are reported. Gradual change of histological appearance of the tumor during his course of 3 years and elevation of serum alpha-1-fetoprotein (AFP) are documented. Two biopsy specimens showed immature histological appearance compatible with pancreatoblastoma, and autopsy material showed well-differentiated adenocarcinoma with distinct ductal and acinar differentiation. Electron microscopy demonstrated zymogen-like granules in the apical portion of the neoplastic cells. Immunoperoxidase method demonstrated AFP in the neoplastic cells in addition to alpha-1-antitrypsin. Literature of pancreatic tumor in the young was reviewed, and characteristics of this case were discussed. ACTA PATHOL. JPN. 35 : 1543–1554, 1985.     

Pharmacokinetics and metabolism of 5-125I-iodo-4'-thio-2'-deoxyuridine in rodents.

Pharmacokinetics and metabolite analysis of radioiodinated 5-iodo-4'-thio-2'-deoxyuridine (ITdU), a potential tumor cell proliferation-imaging agent, were investigated in rodents. METHODS: Blood and urine metabolites of radiolabeled ITdU were analyzed by thin-layer chromatography in rats. Tissue fractionation studies in mice were also performed to investigate the incorporation of (125)I-ITdU into DNA. RESULTS: The blood distribution study suggested the influx of (125)I-ITdU into rat peripheral blood cells. The blood metabolism of (125)I-ITdU in vitro was negligible. Plasma analysis at 60 min after injection showed that 50% of the radioactivity was intact (125)I-ITdU. The plasma clearance of (125)I-ITdU showed a biexponential function with half-lives of 0.2 and 29.5 min, representing 94.2% and 5.8% of plasma (125)I-ITdU concentration, respectively. (125)I-ITdU was excreted in urine 86% intact at 3.5 h after injection. Extraction of the tissues demonstrated that >70% of the activity in the duodenum, spleen, and thymus was incorporated into DNA at 8 h after injection. On the other hand, <8% of the activity in the liver was in the DNA fraction at that time. CONCLUSION: These data demonstrate that (125)I-ITdU is less susceptible against catabolism and readily incorporated into DNA in proliferating tissues. Therefore, (125)I-ITdU may be useful in measuring DNA synthesis with SPECT.     

An Autopsy Case of Renal Cell Carcinoma Associated with Extensive Peliosis Hepatis

An autopsy case of renal cell carcinoma with extensive peliosis hepatis is reported. The patient was a 34-year-old female, who had had a left nephrectomy for renal cell carcinoma but died of multiple metastases one year and 4 months after surgery, despite chemotherapy and interferon treatment. At autopsy, the liver was enlarged markedly with multiple metastatic nodules and the nonneoplastic hepatic parenchyma had a spongy appearance, due to diffusely scattered, blood-filled cystic lesions. Histological examination showed the oval to irregular shaped blood-filled spaces were lined by hepatic cell cords and located mainly in the periportal area. In addition, almost all of the sinusoids were dilated and communicated with the cystic blood-filled spaces, which also communicated directly with branches of the portal veins at various levels. Several interlobular portal branches were obstructed. The causative mechanism of peliosis hepatis has yet to be elucidated, although some causative conditions have been proposed. In this case, renal cell carcinoma may have caused the sinusoidal dilatation and the vascular changes in the portal areas, such as obstruction of terminal portal branches, may have contributed to its formation.     

A case report suggesting a common pathogenesis for IgA nephropathy and Henoch-Schönlein purpura

A 7-year-old boy who had been followed for asymptomatic haematuria and elevated serum IgA levels developed Henoch-Schönlein purpura (HSP) after a streptococcal infection of the tonsils. Findings on renal biopsy were compatible with mild IgA nephropathy (IgAN); tonsillectomy was also performed as he had chronic tonsillitis. This case suggests that there is a common pathogenesis for IgAN and HSP, at least in some patients.     

Endosonographic Staging of Gastric Carcinoma: Factors influencing accuracy

Abstract: Endoscopic ultrasonography has become an important diagnostic procedure complementary to endoscopy and histopathological study in the preoperative evaluation of gastric carcinoma. Despite allowing visualization of tumoral infiltration with quite high accuracy, certain factors have limited the accuracy of this modality or even led to misinterpretation. We designed a prospective study to evaluate the accuracy of gastric carcinoma diagnosis with special reference to factors resulting in misdiagnosis. During a 22 month period, 86 patients with early and advanced gastric carcinoma underwent surgical or endoscopic resection on the basis of endosonographic findings. In all patients, endosonographic findings, location and macroscopic type of the tumor and histopathological characteristics including depth of invasion, malignant cell type and/or differentiation, and the presence/absence of ulceration in the tumor focus were recorded. The endosonographic and histopathological results were compared at the end of the study. Overall accuracy was 85% using the TNM staging system. There were no significant differences in accuracy in the location of the tumor, histological grading or macroscopic type of tumor, although the accuracy rate was lower for tumors located in the antrum. Ulceration in the tumor focus was a major factor leading to misinterpretation of the findings of early gastric cancer (p<0.02). The diagnosis of microinvasion is an issue which remains to be resolved.