Histocytologic diagnosis of pancreatic cancer by percutaneous aspiration biopsy under ultrasonic guidance

Percutaneous aspiration biopsy of the pancreas using a heparinized 22-gauge fine needle was performed under ultrasonic guidance in five patients with benign pancreatic diseases and in 18 patients with pancreatic cancer. Using a heparinized needle and syringe, it was possible to make good smears containing abundant tumor cells and to obtain small tissue specimens. Using egg albumin as binding material, a new cell-block technic was developed to conveniently obtain histologic specimens. In this way, a correct diagnosis was made cytologically in all 23 patients suspected of having a pancreatic malignancy. Histologic specimens were obtained in 22 (95.6%) our of 23 patients. A correct diagnosis was established histologically in all patients from whom histologic materials were obtained. This procedure thus has proved a very reliable method for diagnosing pancreatic cancer.     

LIGHT AND ELECTRON MICROSCOPIC STUDY OF NONFUNCTIONING PARATHYROID CARCINOMA

A case of nonfunctioning parathyroid carcinoma in a 69-year-old female has been studied by light and electron microscopy. The tumor, located on the left side of the anterior neck, was well encapsulated by connective tissue but showed invasion to the capsule and to the thyroid. The tumor cells exhibited a trabecular arrangement surrounded by capillary networks but focally showed several ductal structures. They were polygonal in shape, had a large nucleus showing frequent mitosis and poor cytoplasm containing glycogen. Some tumor cells had clear and abundant cytoplasm, and resembled water-clear cells of the parathyroid. Immunohistochemically, no thyroglobulin was demonstrated in the tumor tissue. Electronmicroscopically, the tumor cells with high N/C ratio contained poorly developed cell organelles and abundant glycogen particles. They were poor in secretory granules and had no conglomeration of lipid. Desmosomes and tonoflbrils were observed. The ratio of the reported number of nonfunctioning parathyroid carcinoma to that of functioning one in Japan was compared with that in western countries. No difference of the ratio was found between these two, when identical criteria were employed.     

Elucidation of the protein kinase C-dependent apoptosis pathway in distinct subsets of T lymphocytes in MRL-lpr/lpr mice

MRL-lpr mice are severely impaired in the Fas pathway of apoptosis induction. We here evaluate another pathway of apoptosis induction in MRL-lpr mice which is protein kinase C (PKC) dependent. Despite the defect of the Fas pathway, apoptosis developed during culture in vitro in splenic T lymphocytes from MRL-lpr mice more extensively than in T lymphocytes from MRL-+/+ mice. Apoptosis induction in the former cells was then found to be greatly promoted by PKC inhibitor H-7, and partially prevented by PKC activator phorbol 12-myristate 13-acetate (PMA). High sensitivity to H-7, but not to PKA inhibitor HA 1004, of these cells for apoptosis induction was confirmed by detailed time course and dose-dependency experiments of the drug effect. Population analysis showed that both CD4⁺ T lymphocytes and CD8⁺ T lymphocytes from MRL-lpr mice were highly sensitive to H-7, whereas CD8⁺ T lymphocytes, but not CD4⁺ T lymphocytes, from MRL-+/+ mice were susceptible to the reagent. Interestingly, B220⁺Thy-1⁺CD4^?CD8^? T lymphocytes from MRL-lpr mice were most sensitive to H-7 for apoptosis induction. Correspondingly, the membrane-translocated activated PKC-α level in splenic T lymphocytes from MRL-lpr was more extensively up-regulated by PMA than in splenic T lymphocytes from MRL-+/+. These results suggest that some signal consistently activates PKC in MRL-lpr T lymphocytes, and this event is needed for survival of these cells. On the other hand, CD4⁺CD8⁺ thymocytes were deleted by apoptosis in culture with PMA, whether these thymocytes were from MRL-lpr mice or MRL-+/+ mice. This finding suggested that the apoptosis induction pathway linked to PKC activation is intact in CD4⁺ CD8⁺ thymocytes from the Fas-defective MRL-lpr mice. We conclude from these results that the PKC-dependent signal pathways for either cell death or cell activation are intact or even accelerated in lpr mice, which could both compensate for the loss of the Fas pathway and promote the generation of autoreactive T lymphocytes.     

Inhibitory effect of antiserum to surface antigen P50 of Babesia gibsoni on growth of parasites in severe combined immunodeficiency mice given canine red blood cells

The inhibitory effect of an antiserum to surface protein P50 of Babesia gibsoni on the growth of the parasite was determined with severe combined immunodeficiency mice given canine red blood cells. The antiserum to the recombinant P50 protein significantly inhibited the parasite growth, indicating that P50 might be a useful vaccine candidate.     

Comparison of mutagenic potentials and mutation spectra of benzene metabolites using supF shuttle vectors in human cells

Benzene is a human leukemogen and the metabolites are thought to be deeply involved in benzene leukemogenesis. In a previous study we reported the molecular analysis of p-benzoquinone (p-BQ) mutagenesis by using a supF shuttle vector plasmid and here we report the mutagenesis of the other metabolites, hydroquinone (HQ) and trans, trans-muconaldehyde (MUC). HQ is a precursor of p-BQ and MUC is produced by a ring-opening metabolic pathway. We found that the HQ redox cycle produced an oxidative lesion in plasmid DNA and significant differences among the mutagenic potentials of MUC, HQ and p-BQ. HQ has stronger mutagenicity than the others. It is about 20 and 600 times stronger than p-BQ and MUC, respectively. Furthermore, we found notable differences in each mutational feature. The MUC mutational type was characterized by a high frequency of tandem base substitutions that could be due to crosslinks produced by its aldehyde moieties, while HQ was characterized by frequent deletion. This HQ feature is the same as in vivo benezene mutagenesis of Big Blue mice reported by Provost et al. in 1996 and is also quite similar to a hydrogen peroxide mutational feature. Therefore, we presume that HQ and reactive oxygen species may play an important role in benzene carcinogenesis.     

Selection of higher molecular weight genomic DNA for molecular diagnosis from formalin-fixed material.

The patterns of DNA degradation in frozen, methanol-fixed, and formalin-fixed tissues were investigated by high-performance liquid chromatography (HPLC). The chromatograms all yielded one major peak with or without several extra minor peaks representing molecular weights of preserved genomic DNA. The most characteristic differences were in the retention times of the major peaks, with the earliest major peak occurring in the formalin-fixed tissues, and followed by the methanol-fixed, and frozen tissue samples, in that order. This means that the molecular weight of the DNA from formalin-fixed tissue is much shortened than that recovered from methanol-fixed tissue and frozen tissue. The results also indicated that a small amount of higher molecular weight DNA is still preserved in formalin-fixed tissues. To improve the amplification efficiency of polymerase chain reaction (PCR) analysis of formalin-fixed material, we isolated the higher molecular weight DNA from formalin-fixed, paraffin-embedded tissue from four different organs and compared the amplification efficiencies with those of the crude DNA extract. We used eight sets of oligonucleotide primers producing 262 to 989 base pair (bp) fragments of beta-globin. The results showed that the PCR amplification analyses were more efficient with the isolated higher molecular weight DNA than with the crude DNA extract. Our study demonstrated that not all the DNA in formalin-fixed, paraffin-embedded tissue samples is totally degraded but that a small amount of higher molecular weight DNA persists. The feasibility of molecular diagnosis using formalin-fixed material can be improved by isolating the preserved higher molecular weight DNA by HPLC.     

Interleukin-4 and Interferon-γ Inhibit Prostaglandin Production by Interleukin-1β-Stimulated Human Periodontal Ligament Fibroblasts

The purpose of the present study was to investigate the involvement of cyclooxygease-1 (COX-1) and cyclooxygenase-2 (COX-2) in prostaglandin (PG) production by human periodontal ligament (PDL) fibroblasts stimulated with a proinflammatory cytokine, inerleukin-1 (IL-1), and to examine the effect of interleukin-4 (IL-4), a Th2 cytokine, and interferon- (IFN-), a Th1 cytokine, on PG production by the cells. IL-1-stimulated PDL fibroblasts produced prostaglandin E₂ (PGE₂) in a time-dependent manner. Indomethacin, a non-selective COX-1/COX-2 inhibitor, and NS-398, a selective COX-2 inhibitor, completely inhibited PGE₂ production by IL-1-stimulated cells. Northern blot analysis showed that COX-2 mRNA was detected in IL-1-stimulated PDL cells, although not detected in unstimulated cells, while expression of COX-1 mRNA was in the same extent in both the cells. Dexamethasone inhibited COX-2 mRNA expression, COX activity and PGE₂ production in IL-1-stimulated cells. IL-4 and IFN- suppressed PGE₂ production by IL-1-stimulated PDL fibroblasts, but COX activity enhanced by IL-1 treatment was significantly inhibited by IL-4, not by IFN-. Northern blot analysis showed that IL-4 depressed COX-2 mRNA expression with no effect on COX-1 mRNA expression. On the other hand, IFN- had no effect on expression of COX-1 and -2 mRNA. These data suggest that COX-2 is primarily responsible for PGE₂ production by IL-1-stimulated human PDL fibroblasts and that IL-4 inhibited PGE₂ production by IL-1-stimulated PDL fibroblasts through down-regulation of COX-2 expression, while IFN- suppressed the PGE₂ production with no effect on COX-2 expression.     

Retroperitoneal liposarcoma presenting a indirect inguinal hernia

A 60-year-old man was admitted to our hospital with a right inguinal swelling that had been growing in size without any pain for 7 months. We diagnosed the growth as a right inguinal hernia and operated on him. The growth, however, was found to be a tumor it situated along the spermatic cord and testicular vessels. We diagnosed it as a lipoma. The tumor was resected near part of the internal inguinal ring. Histopathological diagnosis showed well-differentiated liposarcoma of the sclerosing type. Postoperative computed tomography (CT) revealed a large residual tumor in the retroperitoneum. We believed that the tumor was a retroperitoneal liposarcoma and that it developed in the inguinal region. The residue of the liposarcoma was resected onto the right inguinal tract. A periodic follow up has been performed and no evidence of recurrence or metastasis has been seen in the 4 years and 9 months since the second surgery. No adjuvant therapy was performed. Inguinal liposarcomas are relatively rare and in most cases these tumors are thought to originate in the spermatic cord. The origin of the tumor is believed to be the retroperitoneum.     

Cloning of a Novel Babesia equi Gene Encoding a 158-Kilodalton Protein Useful for Serological Diagnosis

In this study, we characterized a Babesia equi Be158 gene obtained by immunoscreening a B. equi cDNA expression phage library with B. equi-infected horse serum. The Be158 gene consists of an open reading frame of 3,510 nucleotides. The recombinant Be158 gene product was produced in Escherichia coli and used for the immunization of mice. In Western blot analysis, mouse immune serum against the Be158 gene product recognized 75- and 158-kDa proteins from the lysate of B. equi-infected erythrocytes. In an indirect fluorescent-antibody test with the mouse immune serum, the Be158 antigen appeared in the cytoplasm of Maltese cross-forming parasites (which consist of four merozoites) and was located mainly in the extraerythrocytic merozoite body. When the recombinant Be158 gene product was used in an enzyme-linked immunosorbent assay as a serological antigen, it was found to react to B. equi-infected horse sera, indicating that the Be158 gene product is useful as a serologically diagnostic antigen for B. equi infection.