A case of thymic cyst with thymic hyperplasia]

A 70-year-old man was admitted to our hospital for treatment of an anterior mediastinal tumor. Although he was asymptomatic, an abnormal shadow was visible on chest radiography. CT revealed a heterogeneous tumor located in the anterior mediastinum. On MRI, the tumor demonstrated low signal intensity in T1-weighted images and high signal intensity in T2-weighted images. Laboratory data, including tumor markers, were mostly within the reference ranges. Although a CT-guided needle biopsy was performed, histologic diagnosis could not be confirmed. We resected the tumor with the thymus by median sternotomy. Histopathological examination demonstrated that the tumor was a multilocular thymic cyst with thymic hyperplasia and numerous lymphocytes. The lining epithelial cells gave positive reactions to immunohistochemical staining for carbohydrate antigen 19-9. Carcinoembryonic antigen and squamous cell carcinoma antigen levels in the cystic fluid were elevated. This case appeared to be an acquired thymic cyst with thymic hyperplasia. There are few reports of such cysts.     

Endothelin-3 immunoreactivity in gonadotrophs of the human anterior pituitary.

Endothelin (ET), originally discovered in vascular endothelial cells, has also been demonstrated in nonvascular tissues. The present study was undertaken to elucidate the presence of ET in the human pituitary. The avidin-biotin complex method with antiserum to ET-1 (and ET-2) or ET-3 was used to identify ET in human pituitaries obtained by autopsy. ET-3 immunoreactivity was found in the cytoplasm of large ovoid cells of the anterior pituitary. Using the double staining method, the cells containing ET-3 immunoreactivity were differentiated from cells containing ACTH, TSH beta, GH, PRL, and protein S-100. By staining with anti-LH beta antiserum in adjacent sections and using the double staining method, the cells were identified as gonadotrophs. No staining was observed in the posterior pituitary. In addition, no ET-1 (and ET-2) immunoreactivity was detected. The specific localization of ET-3 immunoreactivity in the gonadotrophs of the human pituitary suggests a possible role of ET-3 in the regulation of anterior pituitary function.     

Hypertension in patients on chronic hemodialysis: the role of the renin-angiotensin system

The effects of volume-loading and removal on mean blood pressure were evaluated in patients with high blood pressure and on chronic hemodialysis. Simultaneous measurements of plasma renin activity, plasma angiotensin II and plasma norepinephrine were made. The patients were divided into two groups according to their levels of plasma renin activity. Group 1 (n = 10) had a basal plasma renin activity below 2.5 ng/ml/hr while the level in group 2 (n = 5) exceeded 2.5 ng/ml/hr. The mean blood pressure of the two groups was 105 +/- 5 mmHg and 107 +/- 4 mmHg, respectively. On the day of hemodialysis, saline loading (0.5 ml/kg/min for 20 min) was followed by routine hemodialysis. The mean blood pressure rose to 113 +/- 6 mmHg in group 1. However, the patients in group 2 did not respond to volume loading and hemodialysis. The plasma renin activity, plasma angiotensin II and plasma norepinephrine were not changed by volume loading in both group 1 and 2. Volume removal by hemodialysis caused a reduction in mean blood pressure in group 2 without alteration of vasoactive hormones. In group 1, the mean blood pressure was not reduced by hemodialysis, accompanied by increases in plasma renin activity, plasma angiotensin II, and plasma norepinephrine. In the high renin group, elevated circulating angiotensin II maintained a high blood pressure and in the low renin group, the renin-angiotensin system influenced the prevention of fall in blood pressure after hemodialysis. These results suggest that the renin-angiotensin system plays an important role in the regulation of blood pressure in relation to volume status regardless of whether the plasma renin activity is high or low.     

Molecular investigation of pathogenic factors of suspected-diarrheogenic Escherichia coli isolates from patients feces

One hundred fifty-one O serotypable Escherichia coli strains which were assumed diarrheogenic E. coli among 2,240 strains of E. coli isolated from the in- and outpatients stools with or without gastrointestinal symptoms at Kyorin University Hospital from February 1994 to September 1996 were examined for the relationship between the possession of eight pathogenic factor-related genes and gastrointestinal symptoms of the patients using the polymerase chain reaction (PCR) for these strains. The rate of possession of pathogenic factor-related genes in the E. coli examined was 20.5% (31 strains) and gastrointestinal symptoms were found in all the patients with these strains except one. In the patients without gastrointestinal symptoms, E. coli isolates that possesses these genes was detected in only one case during 61 cases. The respective genes detected were eaeA and astA in each 14 strains, VT1 in 6, VT2 in 5, ST1b in 4, aggR in 3 and LT in 2, ST1a and invE gene was not detected. In particular, the O157 strains were found in 55.6% (5/9 strains) for these genes, and individual strains had VT1, VT2, eaeA and astA genes simultaneously. In contrast, none of these related genes was found in 9 strains of enteroinvasive serotype but enteropathogenic E. coli-related genes were found in 3 strains. The rate of possession of the genes related to enterotoxigenic E. coli, O159 which was most frequently isolated was low as 2.3% (1/43 strains, astA gene) and there were strains showing low correlation to the state of possession of the genes with the O serotype. Since the prevalence of the gastrointestinal symptoms is clearly high for the case which possesses the strain of which the pathogenic factor-related gene was detected, it was suggested that detection of pathogenic factor-related genes in E. coli isolates from feces using the PCR could be an effective means to decide whether the bacteria concerned was a causal bacteria or not in clinical practice.     

Phenotyping of malignant hematopoietic cells

Summary 1255 cases of leukemia-lymphoma were tested between 1972 and 1984 by multiple marker analysis. Routine leukemia phenotyping was performed using standard morphological and cytochemical techniques in combination with clinical and histo-pathological information; the main emphasis was put on immunological surface marker analysis using erythrocyte rosette assays, TdT and a large panel of poly- and monoclonal antibody tests. The 1255 cases were divided into these major types and subtypes: 349 cases of ALL and related immature T- and Burkitt-lymphomas (cALL, pre B-ALL, B-ALL and Burkitt-lymphomas, T-ALL and immature, mostly leukemic T-lymphomas, Null-ALL), 454 cases of mature T- and B-cell malignancies (T-CLL, mycosis fungoides, Sezary-syndrome, T-lymphomas, B-CLL, hairy cell leukemia, multiple myeloma, B-lymphomas), 263 cases of acute myeloid leukemias (AML, AMMoL/AMoL), 182 cases of chronic myeloid leukemias (CML in chronic phase, CMoL, CML in blast crisis), 6 cases of erythroleukemia and 1 case of megakaryoblastic leukemia. A simplified classification scheme which has been used in our laboratories is presented. Phenotyping is of diagnostic, prognostic and therapeutic relevance, most evidently for patients with ALL. Routine leukemia phenotyping should be performed with highly standardized techniques and reagents and by combining information from several fields in the multiple marker analysis. New areas of leukemia research might become very useful for the routine procedure of phenotyping.Abbreviations ALL acute lymphoblastic leukemia - AML acute myeloblastic leukemia - AMMoL acute myelomonoblastic leukemia - AMoL acute monoblastic leukemia - cALL common ALL - CLL chronic lymphocytic leukemia - CML chronic myelocytic leukemia - CML-BC CML in blastic crisis - CMoL chronic monocytic leukemia     

Rotavirus infections in traveler's diarrhea

We tried to isolate rotaviruses from travelers with diarrhea arriving at Nagoya International Airport. 1. Ten cases revealed positive for rotavirus out of 334 diarrheal patients tested during a period from 1985 to 1988. 2. Most of the rotavirus positive cases were in their forties or in their fifties. 3. Geographic distribution of the infected area of the cases was not concentrated with specific countries. 4. Diarrhea was the most frequent clinical manifestations of the cases. 5. There was no cluster in seasonal distribution of the cases.     

A case of hepatocellular carcinoma with tuberculoma within tumor tissue

We made a diagnosis of hepatocellular carcinoma and performed partial resection of the liver in a 72 year-old woman. Granulomas were observed within hepatocellular carcinoma in the surgical specimen. Microscopic findings demonstrated the granulomas particularly within the tumor, and showed that they were composed of epithelioid cells with caseous necrosis. These tuberculomas compressed the tumor cells, and many lymphocytes had infiltrated the tumor around the tuberculomas. The cancer stage of the patient was early and her prognosis is good.