Bcl-2 oncoprotein expression and apoptosis in neuroblastoma

Bcl-2 protooncogene, originally discovered at the chromosomal breakpoint of the t(14;18) in follicular lymphoma, is known to regulate the process of programmed cell death or apoptosis. The inhibition of apoptosis is thought to be one of the mechanisms involved in the development of tumors. To investigate the possible association of bcl-2 protooncogene with the tumorigenesis of neuroblastomas, the authors examined bcl-2 expression by immunohistochemistry in 49 neuroblastomas and 7 ganglioneuromas. The distribution of apoptotic cells was also examined by the TUNEL method (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling). Bcl-2 oncoprotein was detected in the cytoplasm in 40 of 49 neuroblastomas (81.6%). There was no correlation between bcl-2 oncoprotein expression and the clinical features of neuroblastoma. The incidence of bcl-2-positive tumors in ganglioneuroma was significantly lower than that in neuroblastoma (28.6%) (P < .01). TUNEL stained the nuclei of tumor cells in 11 of 34 (32.4%) neuroblastomas. TUNEL-positive cells tended to be located around calcifications in neuroblastomas in patients less than 1 year old. Examination of serial sections showed that apoptotic cells were distributed in the area where bcl-2 oncoprotein was not expressed. What we have observed indicates that apoptosis of neuroblastoma cells may be regulated by bcl-2 expression. Our observations suggest that the survival of neuroblastoma cells might be promoted by bcl-2 expression and that bcl-2 might be associated with the tumorigenesis of neuroblastomas.

3,4-dihydroxyphenylalanine (DOPA) decarboxylase deficiency and resultant high levels of plasma DOPA and dopamine in unfavorable neuroblastoma

Neuroblastoma (NB) is a tumor which arises from neural crest cells. In the developing neural crest cells, the induction of 3,4-dihydroxyphenylalanine (DOPA) decarboxylase is more delayed than that of tyrosine hydroxylase and dopamine-beta-hydroxylase. If NB cells are arrested in an early stage of neural crest development, the induction of DOPA decarboxylase is insufficient and the accumulation and secretion of DOPA can be caused. The biochemically immature phenotype is thought to represent the undifferentiated characteristics of the cells and might correlate with the grade of malignancy. To investigate whether the hypothesis is clinically applicable or not, we have measured plasma DOPA, dopamine and urinary catecholamine metabolites in NB patients. The levels of plasma DOPA, dopamine, urinary homovanillic acid (HVA) and vanillactic acid (VLA) were significantly higher in patients with unfavorable NBs and the higher plasma DOPA level was significantly associated with the patients' age (> 1 year old), tumor stage (III, IV) and DNA diploidy. Serial determination of plasma DOPA was a good monitor of the disease course. These results are compatible with the hypothesis on DOPA decarboxylase deficiency and DOPA secretion in undifferentiated, unfavorable NBs. In conclusion, the plasma DOPA can be used to predict patients' prognosis as well as to follow up patients with NB.

Molecular cloning of cDNA for equine ovarian inhibin/activin beta A subunit

cDNAs encoding equine inhibin/activin beta A subunit were isolated from an equine follicle cDNA library and characterized. Using primers based on the rat inhibin/activin beta A subunit cDNA sequence, a RT-PCR was performed to generate the probe for screening. Four positive clones were isolated. Analysis of the nucleotide sequence of these clones revealed that two pairs of identical clones were present, Eq-beta A-1 (0.9 kb) and Eq-beta A-2 (1.5 kb). Eq-beta A-2 clone contained a complete open reading frame encoding 426 amino acids. The deduced amino acid sequence of equine inhibin/activin beta A subunit showed high similarity (> 90%) to those of five other mammalian species. Northern blot analysis revealed that placenta from mare on day 180 of pregnancy contained a 1.5 kb inhibin/activin beta A subunit mRNA.

Retrospective analysis of biological factors in a recurrent IV-S neuroblastoma with intermediate-grade malignancy

A clinical stage of IV-S neuroblastoma is known to include heterogeneous tumors. The authors report a case of IV-S neuroblastoma that relapsed after regression 4 years and 10 months after diagnosis. Multiagent chemotherapy was necessary to control the disease, and the patient has been doing well with no evidence of disease for more than 5 years. Although Shimada's classification showed favorable characteristics, N-myc protein was positive and DNA ploidy was diploidy in the tumor at diagnosis. Discrepancy in DNA ploidy was observed and aneuploidy was shown in tumor specimens at recurrence. Experience in this case showed the following important clinical features: (1) IV-S neuroblastoma of intermediate-grade malignancy does exist, and patients with such a disease may be cured by aggressive treatment; (2) Identifying IV-S patients with an unfavorable clinical course is possible by examining biological prognostic factors.

Immunoreactive (ir)-transforming growth factor (TGF)-beta in rat corpus luteum: ir-TGF beta is expressed by luteal macrophages

Western analyses and immunohistochemistry of transforming growth factor beta 1 (TGF beta 1) and TGF beta 2 were performed in rat luteal tissue at either the functional or regressing stage. Anti-TGF beta 1 or TGF beta 2 was localized simultaneously to macrophages within cultured luteal cells and frozen ovarian sections. By Western analysis, an active form of TGF beta (25 kDa) was detected clearly with anti-TGF beta 2 but only faintly with anti-TGF beta 1, and the former band from functional corpora lutea was more intense than that from regressing ones. Treatment with prolactin (PRL), a luteotropic hormone in rodents, also increased the intensity of 25 kDa TGF beta 2 in the corpus luteum. Several specific bands with higher molecular weights than 25 kDa were also recognized with anti-TGF beta 1 or TGF beta 2; they are probably ascribed to latent TGF beta s and/or TGF beta precursor proteins. In cultured luteal cells and frozen ovarian sections, many anti-TGF beta 1 or anti-TGF beta 2 positive cells from functional corpora lutea of pseudopregnant rats were double-stained with anti-macrophage. There were numerous macrophages in structurally regressing corpora lutea of pseudopregnant rats, but most of them were not stained with anti-TGF beta s. These results suggest that the expression of TGF beta, at least for TGF beta 2, is under the influence of PRL in the rat corpora lutea, and that macrophages are responsible for some, if not all, of the immunoreactive-TGF beta in rat luteal tissue.

[Detection of IgE antibodies to salt-insoluble wheat proteins in sera of patients with atopic dermatitis by ELISA and immunoblotting techniques]

Specific IgE antibodies against salt-insoluble wheat proteins were investigated in sera from 60 patients with atopic dermatitis (AD) positive to wheat specific CAP-RAST. The salt-insoluble wheat protein fraction was prepared from whole protein fraction of wheat flour, which was extracted by PBS containing 6 M urea. IgE antibodies to salt-insoluble proteins were detected in 15 of the sera. IgE-ELISA was applied to these 15 sera, with whole wheat proteins, salt-soluble proteins, and salt-insoluble proteins used as antigens. Wheat specific CAP-RAST values correlated well with the IgE-ELISA titers against salt-soluble proteins (r = 0.918 p < 0.001). On the other hand, IgE-ELISA titers against both the salt-insoluble proteins and the whole wheat proteins correlated least with CAP-RAST values (r = 0.161 and r = 0.113). The inhibition tests indicated that IgE antibodies against salt-insoluble proteins were different from those against salt-soluble ones. Thus, IgE antibodies to salt-insoluble proteins were another antigen target of IgE-mediated allergy manifestation. To determine the molecular weight of antigens reacting with IgE, IgE-immunoblotting was performed. Several polypeptides with molecular weights of 33-45, 84, 90 and 98 KD were detected. However, the antigen patterns of the blots varied depending on the sera used. These findings suggest that salt-insoluble wheat proteins are the major antigens in some wheat-dependent AD, and that IgE detection against salt-insoluble wheat proteins is important for the diagnosis of wheat allergy.

Self-reports of memory problems in relatives of patients with probable Alzheimer's disease

This study examined the relationship between subjective memory complaints and performance on tests of memory by relatives of patients with probable Alzheimer's disease (AD) and by older adults without a family history of dementia. Relatives of AD patients did not differ significantly from controls either in level of complaint or in performance on neuropsychological tests. However, among relatives of patients with early-onset AD, significant correlations were found between performance on memory tests and self-rated changes in everyday memory. These findings raise the possibility that relatives who have entered the age range in which their parents or siblings developed dementia symptoms are monitoring their memory performance more diligently than relatives of patients whose illness began at much later ages or persons who have no close relatives with AD.

A case of hepatocolic fistula after percutaneous drainage for a gas-containing pyogenic liver abscess

We describe a rare case of gas-containing pyogenic liver abscess which penetrated the adjacent colon, forming a hepatocolic fistula, after percutaneous transhepatic abscess drainage (PTAD) had been performed. To the best of our knowledge, this is the first report of hepatocolic fistula associated with a gas-forming liver abscess in a diabetic patient, with radiological and surgical confirmation of the fistula.

Changes in endogenous growth hormone secretion and onset of puberty in transgenic rats expressing human growth hormone gene

A chimeric gene comprising murine whey acidic protein (mWAP) and human growth hormone (hGH) was used to produce transgenic rats that express hGH and secrete it into the blood. Two lines of transgenic rats carrying the mWAP/hGH construct were established: Line 1 was characterized by relatively high levels of serum hGH, and Line 2 had relatively low levels. The secretory profiles of rat GH (rGH) as well as hGH, the transgene product, were obtained in transgenic males and females of Line 2; both hGH and rGH serum levels were flattened with no episodic fluctuations, and the overall mean concentration of rGH was significantly lower than in normal littermates. Although the animals of Line 1 showed an accelerated increase in growth rate, those of Line 2 did not. Nevertheless, the onset of puberty in females, as assessed by vaginal opening and occurrence of first ovulation, advanced by 7-8 days in both Lines of animals. Accordingly, the body weight at puberty of Line 2 transgenic females was much lower than that of normal littermates, indicating that continuous hGH expression could induce precocious puberty without enhancing the growth rate.

[Effects of aging on urinary secretion of 3-hydroxyproline and its importance for cancer screening in the elderly with ROC analysis]

OBJECTIVE

to observe the influence of aging on urinary secretion of 3-hydroxyproline (3-Hyp) in normal subjects and in cancer patients and study the effects of aging on the accuracy of urinary 3-Hyp as a general-purpose cancer screening test.

DESIGN

We reanalyzed, from the aspect of gerontology, the amounts of 3-Hyp in the urine samples of the 211 healthy persons and 94 patients with cancer reported earlier. The two groups were divided in 3 age subgroups: adult, 30 to 44 years, middle-aged, 45 to 64 years, and aged, 65 years and older. The cancer stage was separated into 3 categories: stage 1, the early stage without any invasion, stage 2, locally invasive with no distant metastasis, and stage 3, advanced cancer. The correlation of age and urinary 3-Hyp was analyzed in normal subjects and cancer patients. Sensitivity and specificity were calculated for different cutoff points in the diverse groups to construct the receiver operating characteristic (ROC) curves.

MAIN RESULTS

We observed that aging decreases the urinary secretion of 3-Hyp in normal subjects, with a correlation coefficient of -0.250 (p < 0.001). The mean levels of urinary 3-Hyp in patients with cancer were significantly higher than in the normal subjects, p = 0.005. The correlation coefficient of urinary 3-Hyp and age was not significant (0.100) in cancer patients. The cutoff points of 0.800 mg/g creatinine of urinary 3-Hyp for persons under 65 years of age and 0.600 mg/g creatinine for persons 65 years or older were the best thresholds for cancer screening. In the ROC analyses, we observed that 3-Hyp has higher accuracy for cancer screening in the aged group for all stages together and in the aged and middle-aged for early stages of cancer.

CONCLUSIONS

The urinary 3-Hyp test was more effective for cancer screening in old persons (65 years or older), where cancer is more frequent and more difficult to discover. The authors stress the necessity and importance of verifying the effectiveness of urinary 3-Hyp for general cancer screening in a larger population and in a community set.

Targeting of the immunoglobulin-binding domain of protein A to the extracellular matrix using a minifibronectin expression vector

A truncated form of fibronectin consisting of the N-terminal 70-kDa and C-terminal 37-kDa regions, referred to as "minifibronectin," retains the ability to assemble into the extracellular matrix, even though it lacks the central approximately 120-kDa region containing most of the type III modules (Ichihara-Tanaka, K., Titani, K., and Sekiguchi, K., FEBS Lett. 299, 155-158, 1992). Taking advantage of the matrix assembly activity of minifibronectin, we developed a novel method to target non-matrix proteins to the extracellular matrix by inserting them between the N-terminal 70-kDa and the C-terminal 37-kDa regions of minifibronectin. Using the immunoglobulin-binding domain of Staphylococcal protein A as a model, we demonstrated that the bacterial protein expressed in mouse L cells as a chimeric protein with minifibronectin is secreted as disulfide-bonded dimers and successfully deposited onto the extracellular matrix of transfected cells. The chimeric protein retained the immunoglobulin-binding activity not only in solution but also after deposition at the matrix. This targeting strategy we developed will provide a means to manipulate the biological functions of the extracellular matrix through targeting of a wide variety of non-matrix proteins.

Potassium and calcium channel involvement in induction of long-lasting synaptic enhancement by calyculin A, a protein phosphatase inhibitor, in rat hippocampal CA1 region

In the Schaffer collateral-CA1 pathway in rat hippocampal slices, exposure to calyculin A induced a long-lasting potentiation of the extracellular field potentials with a transient increase in glutamate release. The synaptic enhancement produced by calyculin A was blocked by staurosporine and nicardipine, but not by D,L-2-amino-5-phosphonovalerate. In dissociated CA1 pyramidal cells, calyculin A blocked the action-potential repolarization and fast after-hyperpolarization, and increased spike frequency. These results suggest that calyculin A-induced long-lasting potentiation is triggered by the blockade of Ca(2+)-activated K+ channels, the transient increase of glutamate release and the consequent activation of voltage-gated Ca2+ channels, and is maintained by increases in protein kinases activities.

SecF stabilizes SecD and SecY, components of the protein translocation machinery of the Escherichia coli cytoplasmic membrane

The effect of the overproduction of SecF encoded by the tac-secF gene on a plasmid on the synthesis of other Sec proteins was studied in Escherichia coli. SecF overproduction resulted in the simultaneous overproduction of SecD encoded by the tac-secD gene on a plasmid. Deletion of the orf6 gene, located downstream of the secF gene, had no effect on SecD overproduction. A pulse-chase experiment revealed that the overproduction was due to stabilization of SecD with SecF. SecF overproduction also resulted in the overproduction of SecY encoded by the tac-secY gene on a plasmid as well. SecF overproduction also enhanced the level of SecY expressed by the chromosomal secY gene. This SecF effect was not due to its effect on SecD or SecE, since SecF overproduction did not affect the levels of SecD and SecE expressed by the chromosomal secD and secE genes, respectively. SecE-dependent overproduction of SecY has already been demonstrated. It is suggested that SecF interacts with both SecD and SecY. SecE-SecY interaction has been demonstrated. It is likely, therefore, that all Sec proteins in the cytoplasmic membrane interact with each other.

Effect of heat shock on intracellular calcium mobilization in neuroblastoma x glioma hybrid cells

The effect of heat shock on agonist-stimulated intracellular Ca2+ mobilization and the expression of heat shock protein 72 (hsp72) in neuroblastoma x glioma hybrid cells (NG 108-15 cells) were examined. Hsp72 was expressed at 6 h after heat shock (42.5 degrees C, 2 h), reached a maximum at 12 h, and decreased thereafter. Bradykinin-induced [Ca2+]i rise was attenuated to 28% of control by heat shock at 2 h after heat shock, and reversion to the control level was seen 12 h later. When the cells were treated with quercetin or antisense oligodeoxyribonucleotide against hsp72 cDNA, the synthesis of hsp72 was not induced by heat shock, whereas bradykinin-induced [Ca2+]i rise was abolished and the [Ca2+]i rise was not restored. Recovery from this stressed condition was evident when cells were stimulated by the Ca(2+)-ATPase inhibitor thapsigargin, even in the presence of either quercetin or antisense oligodeoxyribonucleotide. Inositol 1,4,5-trisphosphate (IP3) production was not altered by heat shock at 12 h after heat shock, whereas IP3 receptor binding activity was reduced to 45.3%. In the presence of quercetin or antisense oligodeoxyribonucleotide, IP3 receptor binding activity decreased and reached 27.2% of the control 12 h after heat shock. Our working thesis is that heat shock transiently suppresses the IP3-mediated intracellular Ca2+ signal transduction system and that hsp72 is involved in the recovery of bradykinin-induced [Ca2+]i rise.

An unusual presentation of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess: report of a case

We describe a rare case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess in a 59-year-old man. The patient was diagnosed as having a hollow viscus perforation based on a sudden onset of acute abdominal pain along with radiological evidence of bilateral subphrenic feee air (pneumoperitoneum), and underwent an emergency laparotomy. Contrary to expectations, the surgery revealed no perforations of the hollow viscus, but instead a ruptured liver abscess at the dome of the right hepatic lobe was identified associated with suppurative peritonitis. To the best of our knowledge, such a case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing liver abscess is extremely rare.

[Percutaneous retrieval of intravascular foreign body from the pulmonary artery]

Percutaneous retrieval of intravascular iatrogenic foreign bodies is an important part of interventional radiology. Foreign body retrieval from the pulmonary artery is, however, not easy, and only a few cases reports have appeared in the literature. The authors have successfully removed dislodged CV catheter fragments from the pulmonary artery in 8 patients. Combined use of a long sheath and a balloon catheter is very helpful for this retrieval. The long sheath, originally designed for myocardial biopsy, is safely advanced to the pulmonary artery over the balloon catheter. Foreign bodies can be easily caught with a retrieval basket or snare, which is passed through the sheath. Another convenient device is a "balloon snare," which is a hand-made loop snare with an angiographic balloon catheter and a guide wire. For safe and easy retrieval of foreign bodies from the pulmonary artery, we recommend the combined use of a long sheath and a balloon catheter, or a "balloon snare."

Developmental expression of activin/inhibin beta A, beta B, and alpha subunits, and activin receptor-IIB genes in preimplantation mouse embryos

We demonstrated previously that activin A released the two-cell block of mouse embryos cultured in vitro and stimulated early embryonic development. We then confirmed immunohistochemically the presence of the beta A, beta B, and alpha subunits in early embryos together with the oviductal epithelium facing those embryos. The results of in situ hybridization and reverse-transcription polymerase chain reaction here show the presence of mRNA transcripts for activin/inhibin beta A, beta B subunits in the ovary, oviduct, unfertilized egg, and embryo at the early preimplantation stage. However, the mRNA of the inhibin alpha subunit was not expressed in any of these. Considering our previous demonstration of the immunoreactive beta A, and beta B subunits of activin/inhibin polypeptides in the cytoplasm of 1- and 2-cell embryos, we suggest that activins appearing in the oviduct and in embryos are not only transferred from the follicular fluids, but produced by the oviduct, oocytes, and embryos themselves. Since the mRNA of the inhibin alpha subunit was absent at those stages, the beta A and beta B subunits may not exist as the inhibin molecule. The mRNA of activin receptor-IIB was detected in the ovary, in embryos at the 1-cell and the 8-cell/morula stages, and also in the unfertilized egg, although to a lesser extent, but not in the oviduct or in the 2-cell-stage embryo either in vivo or cultured in vitro. These results suggest that activin is physiologically involved in the process of early development of mouse embryos.

HLA class II molecule-mediated signal transduction mechanism responsible for the expression of interleukin-1 beta and tumor necrosis factor-alpha genes induced by a staphylococcal superantigen

Superantigens including staphylococcal enterotoxins (SE) bind to major histocompatibility complex class II molecules and interact with T cells bearing particular V beta chains. SEB was shown to induce the expression of interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha genes in human peripheral blood monocytes bearing HLA class II molecules. Monoclonal antibodies directed against HLA-DR and -DQ abolished the SEB-induced expression of both the IL-1 beta and TNF-alpha genes, suggesting that the HLA class II molecules mediated the gene expression. Therefore, we investigated the signal transduction mechanism responsible for the expression of IL-1 beta and TNF-alpha genes induced by binding of SEB to the HLA class II molecules. Three protein tyrosine kinase (PTK) inhibitors, genistein, herbimycin A, and tyrphostin, each of which has a different mechanism of action, strongly inhibited the expression of the monokine mRNA induced by SEB. Analyses of PTK activity revealed that SEB induced a rapid increase of membrane-associated PTK activity and this was blocked by tyrphostin. Furthermore, H-7 inhibited the expression of the monokine mRNA induced by SEB, suggesting the involvement of protein kinase C (PKC) in the signaling pathway. The involvement of PKC was confirmed by the observations that phorbol 12-myristate 13-acetate (PMA), a direct activator of PKC, induced the expression of the monokine mRNA and that SEB evoked the activation of membrane-associated PKC. Both activation of PKC and expression of the monokine mRNA induced by SEB appeared to be inhibited by tyrphostin, but those induced by PMA were not. Taken together, these findings indicate that both PTK and PKC play essential roles in HLA class II molecule-mediated signal transduction elicited by SEB and that PTK activation may precede PKC activation in the signaling pathway.

Small bowel obstruction in children: review of 10 years experience

Small bowel obstruction, excluding postoperative adhesive ileus, in patients > 1 month old treated between June 1982 and May 1992 at Gunma Children's Hospital Medical Center is reviewed. There were 32 patients, 22 boys and 10 girls, whose ages ranged from 1 month to 6 years (median 9 months). Intussusception was the most frequent cause of obstruction and was seen in 17 patients (53.1%). Causative lesions were identified in five patients, and were ileal duplication cysts in four and Meckel's diverticulum in one. Incarcerated inguinal hernia and mesenteric cysts resulted in bowel obstruction in six and three patients, respectively. Other causes included mesodiverticular band, ileal volvulus without malrotation, abnormal adhesion of omentum, abnormal band, vitelline duct remnant and trapping in a mesenteric defect. As for the age distribution, there was no significant correlation between the causes of obstruction and the age of patients. Ultrasonography was useful in differential diagnosis, and this modality should therefore be used in every patient with signs of small bowel obstruction.

Effect of calyculin-A, phosphatase inhibitor, on 20 alpha-hydroxysteroid dehydrogenase activity in rat luteal cell culture

The effects of calyculin-A (CL-A), a phosphatase inhibitor, on 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) activity were studied in rat luteal cell cultures to examine whether protein phosphatases were involved in the regulation of the enzyme activity. Luteal cells were harvested from the rats on day 6 of pseudopregnancy. In the absence of prolactin (PRL), the stimulatory effect of CL-A (10(-9) M) on 20 alpha-HSD activity was observed during the first 3 h period of the culture, but was not discernible thereafter. Since the enzyme activity of luteal cells during pseudopregnancy is known to be suppressed by PRL, the results suggest that this effect of CL-A could be manifested only as long as the effect of endogenous PRL was remained. On the other hand, CL-A enhanced the 20 alpha-HSD activity of the cells cultured for 24 h, where a spontaneous increase in 20 alpha-HSD activity was blocked by exogenously supplementing the culture medium with PRL. These results suggest that a CL-A sensitive phosphatase(s) may be involved in the action of PRL in suppressing the increase in 20 alpha-HSD activity in rat luteal cells.

Promotion of survival and proliferation by interleukin 3, kit-ligand and erythropoietin on early and late appearing spleen colony forming units in culture

We examined the effects of interleukin 3 (IL-3), kit-ligand and erythropoietin (EPO) on the survival and growth of early appearing spleen colony forming units (CFU-S8) and late appearing CFU-S (CFU-S12) in short-term liquid culture (SLC). In the control cultures, without any additive, CFU-S8 and CFU-S12 declined; nearly 10% of the initial number of CFU-S still survived by the second day of culture. The addition of IL-3 or kit-ligand increased the survival both of CFU-S8 and CFU-S12, with an increased dose of concentration, at final concentrations of 10-200 U/ml and 500-50x dilution, respectively. However, only the survival of CFU-S8 increased when EPO was added up to 10 U/ml, while the frequency of CFU-S12 was not higher than in the control culture. The percentage of CFU-S8 and CFU-S12 in DNA synthesis, evaluated in 3H-TdR cytocide experiments, increased after one day in culture with each of the three factors. The results suggest that all three factors stimulated the proliferation of both populations of CFU-S, but the two populations showed different patterns of response to each factor; EPO stimulates the proliferation of CFU-S12 that differentiate into CFU-S8 that have less capacity for self-renewal, while the addition of IL-3 or kit-ligand causes an increase in the number of both populations due to the stimulation of an earlier stage of stem cell differentiation or self-renewal of CFU-S12. Our experimental system (SLC-CFU-S assay) is useful for evaluating the response of hematopoietic stem cells to cytokines which promote the in vitro survival and proliferation of these cells.

[Retinal ischemic changes in diabetic rats treated with pancreatic islet transplantation beneath the renal capsule]

The effect of pancreatic islet transplantation beneath the renal capsule on retinal and choroidal structure was studied using Lewis rats. Rats were divided into 3 groups: an untreated diabetic group induced by intravenous injection of streptozotocin 65 mg/kg; an islet transplanted group 1 month after induction of diabetic state; and an untreated control group. Whole retinochoroidal units were examined by light and electron-microscopy. In 6 out of 9 cases in the transplanted group, the retina showed marked destructive changes in the outer layer including pigment epithelial cells and vacuolization of the inner layer 6 months after islet transplantation. Occlusion and fibrosis of the choriocapillaris adjoining the degenerated retina were also observed. Such changes were not observed in the other groups. On electron microscopy, occlusion of capillaries and destruction of endothelial cells were frequently found in the degenerated retina. These retinal ischemic lesions appear to be caused by microvascular obstruction.

[A case of intraocular histiocytosis X]

A solitary massive tumor developed in the left eye of a 61-year-old female who had a history of insulin-independent diabetes mellitus for 20 years and whose left eye had become blind due to repeated anterior uveitis in the recent several years. The eyeball was enucleated and used for further examinations. Intraocular tissues were widely infiltrated by histiocytes, though no extraocular invasion or further metastasis was found. Histological examination including alpha 1-anti-chymotrypsin and S100 staining revealed the features characteristic of histiocytosis X. This is probably a case of intraocular histiocytosis X with no evidence of systemic symptoms.

[High-dose busulfan, VP-16 and ACNU therapy with stem cell transplantation for the treatment of children with acute leukemia]

In order to strengthen the anti-leukemia effect, we developed a new conditioning regimen with high dose busulfan, VP-16 and ACNU (BVA) for cytoreduction before stem cell transplantation. Fourteen patients with refractory acute leukemia received allogeneic bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT) after conditioning with the BVA regimen, 7; allogeneic BMT, 1; syngeneic BMT, 6; PBSCT. # Seven patients were transplanted in the first complete remission, and 8 patients were in their second or third remission. Although total body irradiation or cyclophosphamide was not included in this regimen, engraftment was obtained in all cases. Two patients suffered relapse, and one patient died of cytomegalovirus interstitial pneumonitis (IP) 64 days after PBSCT. The other 11 patients are alive and free of disease at a median follow up time of 647 days (98-1235 days). Major regimen-related toxicity was pulmonary complications such as IP (3 cases) and pulmonary edema (2 cases). However, all patients recovered rapidly following steroid therapy. The results indicate that this conditioning regimen is highly effective for the treatment of childhood acute leukemia.