Combination chemotherapy with methotrexate and 5-Fluorouracil and surgery for advanced gastric-cancer with liver and lymph-node metastases - a case-report

We report on a case of advanced gastric cancer with multiple liver metastasis and lymph node metastases in a 65-year-old Japanese man. He was treated with sequential intravenous administration of moderate-dose methotrexate 1 (MTX) and 5-fluorouracil (5-FU) preoperatively. After eleven cycles of the combination chemotherapy, the findings of liver and lymph node metastases diminished dramatically and the tumor could be resected for a potential cure, using a total gastrectomy and combined hepatectomy. The resected specimen revealed a slightly elevated lesion and a somewhat shallow ulceration due to chemotherapy. Histologically, there was an infiltration of poorly differentiated adenocarcinomas with medullary structure in the muscularis mucosae with fibrous change. The liver was metastasized, but there was no evidence-of lymph node metastasis. We believe that combination chemotherapy of MTX and 5-FU can be effective against gastric cancer.

Effects of annetocin, an oxytocin-related peptide isolated from the earthworm Eisenia foetida, and some putative neurotransmitters on gut motility of the earthworm

Annetocin, an oxytocin-related peptide recently isolated from the lumbricid earthworm Eisenia foetida, and putative transmitter substances were examined for their effects on rhythmic, spontaneous contractions of isolated gut preparations of the earthworm. Significant, dose-dependent effects of the following substances were observed: acetylcholine (ACh), gamma-aminobutyric acid (GABA), and dopamine were excitatory, while serotonin (5-HT) and octopamine were inhibitory. Annetocin, oxytocin, and vasotocin stimulated spontaneous contraction of the earthworm gut, annetocin being approximately 10-fold more potent than oxytocin or vasotocin. However, arginine-vasopressin (Arg-vasopressin), lysine-vasopressin (Lys-vasopressin), tocinoic acid (N-terminal hexapeptide fragment of oxytocin), and MSH release-inhibiting factor (MIF; C-terminal tripeptide fragment of oxytocin) did not show any effect on the earthworm gut motility. On the other hand, oxytocin, vasotocin, Arg-vasopressin, Lys-vasopressin, and tocinoic acid caused spontaneous contractions of isolated rat uterine preparations, where the potency was in this order, while annetocin and MIF exerted no oxytocic activity on the uterus. Dose-response relationship of the effects of annetocin and its related peptides on the annelid and mammalian systems shows that amino acid residue at the third position of these peptides is important for exertion of excitatory action on the smooth muscle systems. The results in the present study suggest that receptors for annetocin and for GABA on the earthworm gut, unlike those for ACh, desensitize during continuous exposure to these substances.

Acute myelomonocytic leukemia in a patient with multiple myeloma: evidence for different clonal origin

A case of 77-year-old female with multiple myeloma (IgG-k) developed acute myelomonocytic leukemia (AMMoL) following a myelodysplastic stage after chemotherapy with melphalancyclophosphamide combinations for 6 years. The leukemic blast cells expressed both myeloid antigens (CD11b, CD13, CD14, CD15, CD33 and CD34) and T/B lymphoid antigens (CD2, CD4, CD22 and PCA1). Cytogenetic analysis revealed a chromosome deletion -7. Analysis of immunoglobulin genes showed the heavy chain genes in germ line configuration. These findings indicate that the AMMoL was a therapy-related stem cell leukemia and was a clonal origin genetically different from multiple myeloma irrespective of plasma cell phenotype.

Identification of virulent Rhodococcus equi by amplification of gene coding for 15- to 17-kilodalton antigens

During a survey of the prevalence of virulent Rhodococcus equi at horse-breeding farms by plasmid and protein profiles, cryptic plasmids of various sizes were found in 66 (3.8%) of 1,725 isolates from feces of horses and 129 (5.9%) of 2,200 isolates from soil. Twenty-two isolates, which contained cryptic plasmids of different sizes, were found by plasmid profiles, and their protein profiles and mouse pathogenicities were examined. Of the 22 isolates, 7 were virulent R. equi, contained both virulence and cryptic plasmids, and expressed 15- to 17-kDa antigens. The remaining 15 isolates were avirulent and did not express the antigens: 6 strains contained cryptic plasmids of two different sizes and 9 strains contained cryptic plasmids of various sizes. A PCR assay was developed for the rapid identification of virulence plasmids of R. equi. Oligonucleotide primers, derived from the sequence of a gene coding for the 15- to 17-kDa virulence-associated antigens of R. equi, amplified a 564-bp product from all the tested isolates harboring a virulence plasmid. This PCR product hybridized with virulence plasmid DNA in the Southern hybridization assay. Virulence plasmid-cured derivatives and all of the tested isolates harboring cryptic plasmids only were negative. The PCR is a rapid, sensitive, and specific test for the identification of virulent R. equi from environmental isolates compared with standard techniques, such as plasmid and protein profiles and the mouse pathogenicity test, and is considered to be a useful tool for epidemiological studies.

[Cytophotometrically determined DNA content, mitotic index and proliferative activity clinical gastric cancer]

1) Analyses of cytophotometrically determined DNA content and mitotic index (MI) using histologic sections were carried out in 37 advanced gastric carcinomas. According to the linear regression analysis, there were statistically significant correlations of MI with DNA variants such as the peak value, the mean value and the frequency of cells with values exceeding 4c or 6c (%-over 4c or 6c). When the mean MI was calculated according to the %-over 4c or 6c, there were better correlations of higher MI with increased hyperaneuploid levels. 2) Measurement of DNA content and MI were examined in each layer of 46 tumors with serosal invasion. The mitotic counting analysis revealed a significantly higher value in the serosa, compared with findings in the mucosa. Similarly, the deeper the layer, the higher the %-over 6c. This tendency was evident in cases of an undifferentiated type adenocarcinoma. 3) The relationship between DNA ploidy and tumor invasion was studied in 254 tumors. The frequency of aneuploidy increased with invasion into the deeper layers. Especially in cases of the undifferentiated type, aneuploid carcinoma was free at the stage confined to the mucosa, while the rate was 47% for serosal carcinoma. Thus, abnormal DNA fractions appear to be indicative of tumors with a high mitotic activity and a propensity for growing downward rapidly in the gastric wall.

Excretory/secretory antigens of adult Paragonimus ohirai recognized by a monoclonal antibody

An IgM monoclonal antibody (mAb) that reacted with the gut epithelium and luminal contents of adult Paragonimus ohirai was prepared from a mouse immunized with the excretory/secretory (ES) products of the parasite. The mAb reacted with the same sites not only of immature worms and newly excysted juveniles of P. ohirai, but also of adult worms of other Paragonimus species, such as P. westermani and P. miyazakii. The mAb did not react with adult antigens prepared from any other helminth parasites. Thus, the mAb is a genus-specific antibody against the gut-associated antigen. Immunoblotting revealed that two antigens with molecular masses (M(r)s) of 27 and 29 kDa were present in the ES products of adult P. ohirai, whereas four antigens with M(r) 27, 29, 36, and 38 kDa were detected i adult worm extract. Partially purified fractions containing acidic and neutral cysteine proteinases have 27 and 29 kDa protein molecules reactive with the mAb. The possibilities that the 36 and 38 kDa antigens may be precursors of these proteinases are discussed.

Efficient induction of chromosome-type aberrations by topoisomerase II inhibitors closely associated with stabilization of the cleavable complex in cultured fibroblastic cells

Eukaryotic topoisomerase II (Topo-II) inhibitors such as etoposide, adriamycin and mitoxantrone, which commonly stabilize the cleavable complex of the enzyme and DNA, have been found to efficiently induce chromosome-type aberrations (mainly breaks and exchanges) in cultured Chinese hamster lung fibroblastic cells (CHL cells). To clarify whether the induction of chromosome-type aberrations is mediated by stabilization of the cleavable complex, the present study investigated (1) the correlation between the induction of chromosome-type aberrations and the amount of cleavable complex formed; and (2) the ATP dependence of the Topo-II inhibitor-induced chromosome-type aberrations due to the ATP requirement of cleavable complex formation by Topo-II. First, in cells treated with the Topo-II inhibitors, (etoposide, adriamycin) and aclarubicin, an antagonist of the inhibitor of cleavable complex formation, the frequency of chromosome-type aberrations decreased dose-dependently with aclarubicin, in contrast to an increase of chromatid-type aberrations. The formation of the cleavable complex was further established by a proteinase K/SDS precipitation assay for cleaved double-strand DNA in a cell-free system and in CHL cells. Results from both experiments showed that aclarubicin caused a dose-dependent suppression of the accumulation of the cleavable complex induced by etoposide, which corresponded particularly well to the reduction of chromosome-type aberrations in etoposide-treated cells. In ATP-depleted cells simultaneously treated with etoposide and dinitrophenol (DNP), chromosome-type aberrations were reduced as compared with DNP-untreated cells, in contrast to an increase of chromatid exchanges in the cells. This means that etoposide-induced chromosome-type aberrations in ATP-depleted cells may be attributable to incompleteness of Topo-II activities to form DNA double-strand breaks. The present findings indicate that the stabilization of the cleavable complex on Topo-II is closely associated with the induction of chromosome-type aberrations.

A case of fetal bradycardia and sinusoid-like fetal heart rate pattern associated with maternal hypothermia

A 23-year-old pregnant woman presented with severe hypothermia (33.8 degrees C) as a complication of treatment for urosepsis. The baseline fetal heart rate was 100 beats/min. Despite evidence of variability, a 'sinusoid-like' pattern was observed. However, the fetal heart rate gradually returned to normal after rewarming the patient. This suggests that maternal hypothermia may induce fetal bradycardia and a 'sinusoid-like' fetal heart rate pattern.

The role of gamma delta T cells in priming macrophages to produce tumor necrosis factor-alpha

The secretion of tumor necrosis factor (TNF)-alpha from macrophages is regulated by both priming and triggering signals. We found that macrophages from mice lacking gamma delta T cells [T cell receptor (TCR) delta-/- mice], which lack the gene encoding the delta chain, produced only small amounts of TNF-alpha in response to lipopolysaccharide (LPS) and showed a reduced level of expression of CD14. Pre-incubation of macrophages from TCR delta-/- mice with gamma delta T cells from their TCR delta +/- littermates restored their capacity to produce TNF-alpha in response to LPS. The priming activity of gamma delta T cells was in part inhibited by neutralizing anti-interferon (IFN)-gamma monoclonal antibodies. Collectively, these results suggest that gamma delta T cells play a role in priming macrophages to a steady state of activation via IFN-gamma secretion, which allows them to produce TNF-alpha when exposed to LPS.

The effect of mechanical stress on hypertrophy of the lumbar ligamentum flavum

To clarify the effect of mechanical stress on hypertrophy of the ligamentum flavum (LF), we compared the thicknesses, histological findings, and total collagen content of 161 lumbar LF in two groups defined by radiographic signs. LF with one or more signs of spondylolisthesis, disk degeneration, vacuum phenomenon, traction spur, or facet joint osteoarthrosis were considered degenerative; all others were considered nondegenerative. Thickness was measured by computed tomographic scan, and total collagen content by Woessner's method. We found that the ligament was thicker in the degenerative group (4.0 +/- 1.1 mm vs. 3.0 +/- 0.7 mm, p < 0.01), the degeneration of fibers more severe, and the total collagen content higher (51.9 +/- 14.5% vs. 40.3 +/- 3.9%, p < 0.05). Thus, mechanical stress is considered a cause of ligament hypertrophy.

Physiological study of cervical dystonia. Task-specific abnormality in contingent negative variation

To investigate the pathophysiology of dystonia, we recorded contingent negative variation (CNV) in 12 patients with cervical dystonia and in 12 age-matched normal subjects. In a simple reaction time paradigm, the subjects were given a pair of a warning stimulus and a subsequent stimulus that triggered head rotation to either side or extension of the fingers. In normal subjects, CNVs for head rotation were not affected by neck muscle pre-activation simulating torticollis, and were always symmetrical with equally high amplitudes over the frontal and central leads. By contrast, CNVs for finger movement had the maximum over the central lead and showed a characteristic distribution; those for the right finger movement had the left hemisphere dominance, whereas those for the left finger movement had similar amplitudes over both hemispheres. In patients with rotatory torticollis (rotatocollis), the components of CNVs for head rotation were markedly attenuated in all the leads, except for the initial negative deflection (orienting response). As a whole, cervical dystonia patients had significantly lower amplitudes of late CNVs for head rotation than normal subjects (P < 0.001), whereas late CNV amplitudes in finger extension did not differ in the two groups. Their reaction times for head rotation were similar, but durations of EMG activities were prolonged in the patients because of co-contractions of the antagonists. The task-specific CNV amplitude loss is therefore not explained by reaction times or by the abnormal neck muscle activities prior to the movement, but it reflects a failure of neural activities preparing for a phasic neck movement, resulting in co-contraction of the agonists and the antagonist. Dystonia may be associated with defective retrieval or retaining of specific motor programmes or subroutines in response to sensory stimuli.

Postoperative prophylactic lipiodolization reduces the intrahepatic recurrence of hepatocellular carcinoma

BACKGROUND

To determine a feasible postoperative adjuvant chemotherapy for patients with hepatocellular carcinoma, orally-administered chemotherapy (OC) and prophylactic lipiodolization (selective regional cancer chemotherapy using lipid contrast medium plus an anticancer drug) (PL) were compared prospectively.

PATIENTS AND METHODS

Forty-eight patients who had undergone hepatic resection from 1989 to 1992 were divided into three groups: the control group (n = 19), given no chemotherapy; the OC group (n = 12), given 300 to 400 mg/d of 5-FU derivatives (either 1-hexylcarbamoyl-5-fluorouracil or uracil and tegafur, mean total dosage: 188 g, mean administrative duration: 18 months); and the PL group (n = 17), who underwent prophylactic lipiodolization 1.8 times on average using a 44-mg mean dose of epirubicin per treatment.

RESULTS

No statistical differences were found either in the 25 variables studied as a background analysis, or among the survival curves of the 3 groups. Recurrence was found in 23 remnant livers of the 48 patients. The 3-year, disease-free survival rate was 15%, 50%, and 86% in the control, OC, and PL groups, respectively. The disease-free survival curve of the PL group was significantly higher compared to either the control (P = 0.001) or the OC group (P = 0.025).

CONCLUSIONS

Prophylactic lipiodolization was found to be an effective treatment for patients with hepatocellular carcinoma for reducing intrahepatic recurrence after resection.

Influence of lipiodolization on a cirrhotic liver

Lipiodolization--selective regional cancer chemotherapy using Lipiodol plus an anticancer drug (LPD)--can prolong survival time of patients with an unresectable hepatocellular carcinoma (HCC). To enhance understanding of LPD's influence on the cirrhotic liver, we carried out related studies. Forty-three cirrhotic patients with HCC were treated with LPD (epirubicin in a dose of 15-40 mg/m2 and Lipiodol of 0.02-0.25 ml/kg). Seven cirrhotic patients with HCC were subjected to hepatic angiography alone, and these subjects selected randomly served as controls. Among the 43 treated with LPD, 23 belonged to Child's class A, 15 to class B, and 5 to class C. Blood samples were taken before angiography (pre) and at 24 hours after angiography (post) from each patient. Post/pre ratio of the following parameters were compared between patients of the two groups: sGOT, sGPT, and LDH as a marker for hepatocyte injury; t. bilirubin and hepaplastin test (HPT) as hepatocyte function; alkaline phosphatase and gamma-GTP to examine bile duct injury; and serum hyaluronic acid level to determine an endothelial cell functions. Post/pre ratio of serum GOT, GPT, LDH levels, and HPT in patients treated with vs. without LPD were 1.32 +/- 0.59 vs. 0.92 +/- 0.09 (P < 0.001), 1.18 +/- 0.43 vs. 0.88 +/- 0.09 (P < 0.001), 1.11 +/- 0.20 vs. 1.00 +/- 0.07 (P < 0.05), and 0.95 +/- 0.10 vs. 1.09 +/- 0.12 (P < 0.01), respectively. There were no significant differences in post/pre LPD ratio of other parameters, rates of complications, and hospital stay after LPD for patients with Child's class A, B, and C. Hepatocytes are apparently the primary site of injury in cases of LPD. LPDs, using epirubicin in a dose of 15-40 mg/m2 and Lipiodol in a dose of 0.02-0.25 ml/kg, proved to be safe for cirrhotic patients with HCC.

Regulation of retinal glial cell proliferation by antiproliferative molecules

Glial cells normally do not proliferate in the adult retina despite the presence of glial mitogens. In this study, we examined the hypothesis that endogenous antiproliferative molecules inhibit the effects of glial mitogens. Using cultures of glial cells obtained from the adult human retina, we found that transforming growth factor beta 2 (TGF beta 2) and a metabotrophic glutamate agonist (t-ACPD) inhibit the mitogenic effects of basic fibroblast growth factor, platelet-derived growth factor, epidermal growth factor and insulin-like growth factor-1. These antiproliferative effects may involve activation of protein kinase C (PKC) since chelerythine, a specific PKC inhibitor, blocks the antiproliferative effects of TGF beta 2 and t-ACPD. Furthermore, exposure of the glia to a phorbol ester mimics the inhibitory effects of TGF beta 2 or t-ACPD. Although TGF beta 2 and t-ACPD markedly inhibit a number of mitogens, they do not alter the mitogenic response of retinal glia to thrombin and glutamate. A common characteristic of the mitogens sensitive to TGF beta 2 or t-ACPD is activation of tyrosine kinase-linked receptors. In contrast, thrombin acts at a G-protein-linked receptor, and glutamate stimulates retinal glial proliferation via activation of an NMDA receptor. It appears that TGF beta 2 and t-ACPD may selectively inhibit retinal glial mitogenesis mediated by activation of tyrosine kinase-linked receptors. Our experiments support the idea that endogenous antiproliferative molecules play a role in preventing glial proliferation in the retina.

A novel therapy for internal hemorrhoids: ligation of the hemorrhoidal artery with a newly devised instrument (Moricorn) in conjunction with a Doppler flowmeter

OBJECTIVES

To assess the usefulness of hemorrhoidal artery ligation (HAL) for internal hemorrhoids with a newly devised instrument (the Moricorn).

METHODS

We devised a new instrument (the Moricorn) that is used in conjunction with a Doppler flowmeter. This instrument allows for easy and safe ligation of the hemorrhoidal artery. HAL with the Moricorn was performed on 116 patients with internal hemorrhoids who had episodes of anal pain, bleeding, and prolapse. One month after treatment, the effect was evaluated on the basis of improvement of symptoms and the shrinkage of hemorrhoidal tissue.

RESULTS

The treatment's effect was observed in 50 of 52 patients (96%) with pain, 50 of 64 (78%) with prolapse, and 92 of 96 (95%) with bleeding. No patient required anesthesia throughout the entire procedure. No major complications were encountered with this treatment.

CONCLUSIONS

HAL with the Moricorn is a simple, safe, and effective method. However, further observations predicated on a longer follow-up, a larger number of patients, and comparisons with other conventional treatments are called for.

Sequence of the Rhodococcus equi gene encoding the virulence-associated 15-17-kDa antigens

The nucleotide sequence of the Rhodococcus equi gene encoding the virulence-associated 15-17-kDa antigens, located on plasmid pREAT701, has been determined. The gene encodes a 19-kDa protein of 189 amino acids, with an Ala-rich leader signal sequence (SS). At least five SS peptidase cleavage sites were found in this region. The molecular diversity of 15-17-kDa antigens might be attributed to the multiple SS peptidase cleavage sites.

Enantioselective determination of thiamylal in human serum by high-performance liquid chromatography

Thiamylal, a widely used anesthetic drug, has two enantiomers. We developed a novel and simple method for measuring thiamylal enantiomers in human serum using reversed-phase high-performance liquid chromatography. R(+)- and S(-)-Thiamylal were separated using a chiral mobile phase containing beta-cyclodextrin, and detected at the range of 50 ng/ml-25 micrograms/ml in serum. The relative standard deviations of R(+)- and S(-)-thiamylal were 3.4-8.7% and 2.8-8.7% for the intra-day assay, and 2.8-12.0% and 2.8-13.0% for the inter-day assay. This method may be applied to enantioselective pharmacokinetic studies of thiamylal.

Effect of prenatal exposure to styrene on the neurobehavioral development, activity, motor coordination, and learning behavior of rats

Maternal Wistar rats were exposed via inhalation to 0, 50, or 300 ppm styrene for 6 h/day during gestation days 7 to 21, and offspring were subsequently evaluated in several neurobehavioral tests. Preliminary results with a small number of litters revealed significant dose-dependent effects in tests performed prior to weaning (surface righting, pivoting locomotion, and bar holding), as well as in tests performed after weaning (motor coordination, open-field behavior, and motor activity). Exposure to low concentrations of styrene (50 ppm) caused disturbances in motor coordination in addition to delaying some motor and reflex developments. Large doses (300 ppm) led to changes in open-field behavior and increases in spontaneous activity in addition to the delay in neurobehavioral developments. Exposure of dams to styrene did not clearly affect the learning behavior of the offspring. It was also observed that age played a role in the differences in styrene's effects on neurobehavioral function. Only subtle effects were found in both open-field behavior and motor-coordination function when compared with control rats at 120 days of age. These results suggest that the functional neurobehavioral development of progeny of dams exposed to styrene (or other solvents) should be further investigated.

Modulation of norepinephrine release by serotonergic receptors in the rat hippocampus as measured by in vivo microdialysis

The functional modulation of norepinephrine (NE) release by serotonergic receptors in the hippocampus of freely moving rats was studied by use of in vivo microdialysis. To stimulate NE release from the nerve terminals, a high concentration of potassium (K+, 120 mM) was added through the perfusion system. The K(+)-evoked NE release was inhibited in a concentration-dependent manner when serotonin (5-HT, 0.01-10 microM) was coperfused with K+. A selective 5-HT3 receptor agonist, 2-methyl-5-HT, mimicked the 5-HT response at a concentration of 0.01 to 10 microM. The 5-HT-induced (1 microM) inhibition of NE release was blocked by pretreatment with ondansetron (1 and 10 microM), a 5-HT3 receptor antagonist. On the other hand, K(+)-evoked NE release was also reduced by coperfusion with the 5-HT reuptake inhibitor, fluoxetine (10 microM), which caused increases in the dialysate 5-HT concentration. The fluoxetine-induced (10 microM) decreases in the K(+)-evoked NE release were prevented by serotonergic denervation caused by pretreatment with 5,7-dihydroxytryptamine (200 micrograms/rat i.c.v.). These results indicate that the inhibition on NE release by fluoxetine was due to increased synaptic concentrations of endogenous 5-HT. The fluoxetine-induced inhibitory effect was furthermore abolished by pretreatment with ondansetron (1 and 10 microM). These findings indicate the possibility that both exogenous and endogenous 5-HT inhibit NE release occurs from the rat hippocampus by 5-HT3 receptors. Thus, the present study suggests that the functional modulation of NE release by 5-HT3 receptors exists in vivo.

Single photon emission computed tomography in systemic lupus erythematosus with psychiatric symptoms

Single photon emission computed tomography (SPECT) with n-isopropyl-p-[123I]iodoamphetamine (IMP) was performed on 20 patients with systemic lupus erythematosus (SLE). Fifteen of the patients showed areas of hypoperfusion. All nine patients who had florid psychiatric manifestations at the time the SPECT was performed had hypoperfusion areas. Four patients who had abnormal SPECT findings during psychiatric remission had psychiatric exacerbation one to six months after the SPECT. Four patients who had no hypoperfusion during psychiatric remission had good psychiatric prognoses. Two patients who had no history of psychiatric abnormality but showed hypoperfusion had psychiatric manifestations one month after the SPECT. The IMP-SPECT may be useful as a biological marker that represents the activity of cerebral involvement underlying psychiatric manifestations and the presence of subclinical CNS involvement.

[Comparison of the long-term results of intra or extracardiac implanted bioprosthetic valves]

The long-term results following intra or extracardiac implanted bioprosthetic valves were compared. Forty-one patients, whose average age at the operation was 43.3 +/- 10.7 (mean +/- SD) year-old, were implanted 33 Hancock and 11 Carpentier-Edwards porcine valves, 35 in mitral, 6 in aortic and 3 in tricuspid position. Twenty-five children, whose average age was 6.0 +/- 3.5 year-old (p < 0.01) at the operation, underwent right ventricular-pulmonary artery conduit repair with 16 Hancock, 7 Carpentier-Edwards porcine valves and 2 Ionescu-Shiley pericardial valves. There were only one late death and one operative death in the patients implanted intracardiac bioprosthetic valves. Seven intracardiac and 12 extracardiac implanted bioprosthetic valves were removed at the reoperation for prosthetic valve dysfunction. The probabilities free from reoperation after 7 and 9 years of follow-up was 91% and 82%, respectively, with intracardiac implanted valves, on the other hand 51% (p < 0.05) and 8.6% (p < 0.05), respectively, with extracardiac implanted valves. Valve dysfunction in extracardiac implantation was mainly related to the stenosis due to fusion of comissure and/or calcification. Regurgitation due to tear and/or perforation was mainly associated with intracardiac implanted bioprosthetic valves.

Ret-oncogene expression correlates with neuronal differentiation of neuroblastic tumors

An antibody to the ret proto-oncogene product (RET) was raised and applied to formalin-fixed, paraffin-embedded neuroblastic tumors (NBTs) to investigate its usefulness in diagnosis and evaluation of cell differentiation. In normal neural crest-derived tissues, most ganglion cells were moderately stained while large ganglion cells were weakly stained. In NBTs, the intensity of the staining in moderately differentiated neuroblasts and small ganglion cells was more prominent than in undifferentiated neuroblasts, while the cytoplasm of large ganglionic cells was weakly stained as in normal ganglion cells. The RET immunoreactivity was compared with that of nine neural and neuroendocrine markers. The results revealed a parallelism with the protein gene product 9.5 (PGP9.5), neuron specific enolase (NSE) and NF-150 kD (NF = M). These findings indicated that the RET immunoreactivity was correlated with ganglionic differentiation and maturation. Thus, RET was considered to be a new marker that would be implemented in diagnosis and estimation of neuronal differentiation of NBTs.