[Laboratory medicine, my philosophy and prospect].

I have been working in the field of laboratory medicine for 45 years including the period of working as a physician. During my career, some of my dreams in laboratory diagnosis have been realized, and some have not. Although the issues changed with time, our basic philosophy has not changed at all. In this session, I would like to discuss "my philosophy of laboratory medicine", that is, what I have intended and what I have done. First, I describe the role of laboratory medicine in the field of clinical medicine. Second, I discuss the value of laboratory tests especially for clinical diagnostics. Third, I summarize the history of clinical pathology with reflection of the past, and my anticipation for the future. Fourth, I mention about the task and responsibility of the laboratory technicians and clinical pathologists, in view of their common purpose, clinical diagnosis. Finally, I discuss the future aspect of laboratory medicine.

[Immunohistochemical identification of proliferating cell nuclear antigen (PCNA) in hematological disorders].

We used bone marrow smears to examine how immunohistochemical identification of PCNA (proliferating cell nuclear antigens) which markers of proliferation, works for various hematopoietic cells in hematological disorders. Short-term fixation with buffered acetone formalin allowed us not only to observe morphosis properly but also to identify the occurrence of PCNA in erythroblasts, megakaryocytes, plasma cells and blasts. For blasts of leukemia patients, we could distinguish more positive cases from less positive ones regardless of the increase or decrease of cells. A change in PCNA due to the existence of neoplastic cells was also observed. These findings suggest that in the future, analyzing the occurrence of PCNA in hematopoietic cells can provide us with immunohistochemically important information on diagnosis of malignancy and follow up.

[Pathological study of carbohydrate antigens in human lung cancer with monoclonal antibodies].

The expressions of carbohydrate antigens were examined with panel of specific anti-carbohydrate monoclonal antibodies (MAbs) on human lung cancer tissues. The MAbs used were SH1, SH2, SNH3, AH6, CA3F4, TKH2, TKH6 and TKH5 which define Lex, dimeric Lex, sialosyl Lex, Ley, Lea, sialosyl Tn, Tn and fucosyl GM1, respectively. Paraffin-embedded tissue sections (30 squamous cell carcinomas, 30 adenocarcinomas and 27 small cell carcinomas) were tested by immunohistological staining. Evaluation of stained specimens was performed by taking mean value of scores evaluated by three independent examiners. In squamous cell carcinoma, expression of Ley, sialosyl Tn, sialosyl Lex and Lea was significantly higher than other antigens. Lex was also expressed especially in keratinized tissues. In adenocarcinoma, Lea was expressed most remarkably. Sialosyl Lex, Ley, sialosyl Tn were also highly expressed in malignant cells. There was no significant difference in staining patterns between well and poorly differentiated adenocarcinomas. Sialosyl Tn and sialosyl Lex were positive in morphologically normal mucous glands adjacent to tumors. In small cell carcinomas, Ley was expressed more than other types of tumors, whereas Lex and sialosyl Tn were less than others. Tn antigen was observed throughout adenocarcinomas, squamous and small cell carcinomas in a relatively weak manner. Dimeric Lex and fucosyl GM1 antigens were not detected. Most of normal lung sections showed negative staining with those MAbs. These findings indicate that there are differential expressions of certain carbohydrate antigens in different types of human lung cancers based on their origins.

[Serum cholesterol levels in normal subjects taking into consideration the accuracy of the measuring system].

Serum cholesterol levels were determined in 5,843 normal subjects aged zero to seventy years. The accuracy of our assay method was checked by Standard Reference Material 909 and Certified Reference Serum, both of which were supplied by the National Bureau of Standards. Reference values of serum cholesterol were confirmed for each age group. That of male subjects in the 15-20 year age group was within a range of 109-203 mg/dl, and that of female subjects in the 20-25 year age group was within a range of 133-215 mg/dl. Therefore, among normal subjects, the above-mentioned age groups had the lowest serum cholesterol levels. Serum cholesterol levels increased with age in both male and female subjects. The upper limit of cholesterol levels was 248 mg/dl for males in the 50-60 year age group and 284 mg/dl for females in the same age group. We observed the necessity of paying consideration those changes which occur with aging, in the determination of reference values of serum cholesterol. Our findings also showed that serum cholesterol levels remained nearly constant in male subjects of all age groups over a period of 25 years. However, we found mean levels in female subjects in the 50-70 year age groups to be significantly elevated, when compared with those observed in persons in the same age group of 25 years previous. We also found that the mean cholesterol level in girls aged 12 years was higher than that of boys the same age.

[Advances of diagnosis and clinical assessments for pancreatic disorders. Remarks].

In spite of the marked advances of laboratory medicine, diagnostic parameters or tools for the pancreatic disorders were now in obscure. However, advances of immunochemical procedures, especially advances of monoclonal antibodies and high performances of immunoassay techniques make it possible to reveal the chemico-pathological status of pancreatic disorders. Moreover, advances of ultrasonic echography and ultrasonically guided biopsy more than make up for the defects of biochemical and immunochemical information. In this symposium, these advances of diagnosis for pancreatic disorders will be studied and discussed.

Sugar chain heterogeneity of bone and liver alkaline phosphatase in serum.

Fractionation of bone and liver alkaline phosphatase (EC 3.1.3.1; ALP) in serum by serial lectin affinity chromatography has demonstrated differences in the sugar chain structure of bone and liver ALP in serum from that previously reported in the corresponding tissues, with a lower content of high mannose or hybrid-type sugar chains and a higher content of biantennary complex-type chains. Furthermore, the bone and liver ALPs were found to differ in the latter with the bone fraction showing a greater content of fucose residues.

[Measurements of prostatic acid phosphatase and prostate specific antigen by fully automated enzyme immunoassay system--its analytical and clinical evaluation].

Analytical and clinical evaluations were made on the measurement of prostatic acid phosphatase (PAP) and prostate specific antigen (PA) by a fully automated enzyme immunoassay system. Results concerning reproducibility, recovery and sensitivity were good. PAP values by this method correlated well with those obtained by radioimmunoassay. PA values by this method were higher than those obtained by other enzyme immunoassays, although the correlation coefficient was high. PAP, PA and gamma-Seminoprotein (gamma-Sm), another prostatic tumor marker, were all poorly correlated to one another. Normal upper value, 2 SD of 720 healthy males was 1.2 ng/ml for PAP, and 3.7 ng/ml for PA. Positive ratios of these tests in 31 patients with prostatic carcinoma were high at advanced stages, and low at early stages. ROC (receiver operating characteristics) curve analysis on patients with prostatic carcinoma and benign prostatic hypertrophy indicated that PAP and PA were more effective than gamma-Sm for the differential diagnosis of prostatic carcinoma, and that the clinical cut off was 2.0 ng/ml for PAP, 7.4 ng/ml for PA and 4.0 ng/ml for gamma-Sm.

[Inflammatory reaction and laboratory tests].

Inflammation is a local reactive process against tissue destruction. In inflamed tissue, there are cell reactions such as migration of leukocytes and mobilization of macrophages, and vascular reactions caused by various inflammatory agents. At this symposium, we discussed the recent trend of laboratory tests that might be sensitive indicators of inflammation. Although most of these indicators are nonspecific for diagnosing diseases, some of them might be important in the study for the pathogenesis and for planning treatment. First Dr. Kasahara spoke on the topic of interleukin 1, one of the most important agents that mediated the tissue reaction. The next speaker reported about a classical acute phase reactant, CRP, and a new indicator, SAA. Then there were presentations of two papers on leukocytes and elastase in granulocyte, respectively.