Binocular Function of Intermittent Exotropia Before and After Surgery

Purpose: We examined the binocular function of intermittent exotropia before and after surgery, and studied the effect of the surgery and the factor that might be involved in its result.Materials and Methods: 402 intermittent exotropic patients, who underwent their first surgical correction for the strabismus at Teikyo University Hospital, were examined for retinal correspondence and stereo acuity before and after surgery.Results: 367 patients (91.3%) had already had good stereo acuity before surgery when their eyes were straight. Regarding retinal correspondence, though 192 patients (47.8%) were abnormal (dual) before surgery, 301 patients (74.9%) were normal after surgery. The eye deviation of 101 patients who could not get normal retinal correspondence after surgery was significantly larger than normal (P <.001), and 77.2% of them had also vertical strabismus which was mainly composed of dissociated vertical deviation.Conclusion: Normal binocular function could be recovered by surgical treatment in most intermittent exotropic patients. When patients could not get normal retinal correspondence after surgery, we supposed that dissociated vertical deviation might exert an important effect upon their binocular function.

Wortmannin sensitizes human glioblastoma cell lines carrying mutant and wild type TP53 gene to radiation

The purpose of this paper is to investigate the effect of wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), on TP53 (formerly known as p53) signal transduction initiated by ionizing radiation and radiosensitization in isogenic derivatives of human glioblastoma cells differing in TP53 status. Wortmannin inhibited the accumulation of TP53 and CDKN1A (formerly known as WAF1) after 6 Gy irradiation in A-172/neo cells bearing wild-type TP53. In A-172/Trp248 cells carrying mutant TP53, X-rays induced no significant accumulation of TP53 and slight increase of CDKN1A. There were, consequently, little differences in the expression of TP53 and CDKN1A between A-172/Trp248 cells exposed to 6 Gy alone and wortmannin plus 6 Gy. However, wortmannin sensitized both A-172/neo and A-172/Trp248 cells to radiation. These studies indicate that wortmannin inhibits TP53 upregulation, but this suppression does not account for the radiosensitization by this drug. These results indicate that inhibitors of PI3K-related kinases may present a new class of radiosensitizers, regardless of the TP53 status of tumor cells.

The role of PPARgamma as a thrifty gene both in mice and humans

The biological role of peroxisome proliferator-activated receptor gamma (PPARgamma) was investigated by gene targeting and case-control study of the Pro12Ala PPARgamma2 polymorphism. Homozygous PPARgamma-deficient embryos died at 10.5-11.5 days post conception (dpc) due to placental dysfunction. Heterozygous PPARgamma-deficient mice were protected from the development of insulin resistance due to adipocyte hypertrophy under a high-fat diet, whose phenotypes were abrogated by PPARgamma agonist treatment. Heterozygous PPARgamma-deficient mice showed overexpression and hypersecretion of leptin despite the smaller size of adipocytes and decreased fat mass, which may explain these phenotypes at least in part. This study reveals a hitherto unpredicted role for PPARgamma in high-fat diet-induced obesity due to adipocyte hypertrophy and insulin resistance, which requires both alleles of PPARgamma. A Pro12Ala polymorphism has been detected in the human PPARgamma2 gene. Since this amino acid substitution may cause a reduction in the transcriptional activity of PPARgamma, this polymorphism may be associated with decreased insulin resistance and decreased risk of type 2 diabetes. To investigate this hypothesis, we performed a case-control study of the Pro12Ala PPARgamma2 polymorphism. In an obese group, subjects with Ala12 were more insulin sensitive than those without. The frequency of Ala12 was significantly lower in the diabetic group, suggesting that this polymorphism protects against type 2 diabetes. These results revealed that in both mice and humans, PPARgamma is a thrifty gene mediating type 2 diabetes.

Intramolecular electron-transfer reaction within a diprotein complex of cytochrome c with ferrylmyoglobin modified with diethylenetriaminepentaacetic acid

Horse heart metmyoglobins modified with diethylenetriaminepentaacetic acid, metMb(DTPA)n (n=1, 2, 4, and 5), were characterized by a MALDI-TOF mass spectrometry, amino-acid sequence analysis, and UV-Vis and CD spectroscopies. The DTPA-binding sites on metMb were Lys47, Lys50, Lys87, Lys145, and Lys147 for metMb(DTPA)5, Lys47, Lys87, Lys145, and Lys147 for metMb(DTPA)4, Lys87 and Lys145 for metMb(DTPA)2, and Lys87 for metMbDTPA, respectively. The modified metMb(DTPA)n showed cytochrome c peroxidase-like activity more efficiently than native metMb: metMb(DTPA)5>metMb(DTPA)4>metMb(DTPA)2> metMbDTPA approximately equals native metMb. The first-order rate constants for the reactions of ferrylMb(DTPA)n (n=2, 4, and 5) with reduced cytochrome c [cyt c(II)] were saturated with concentrations of cyt c(II), suggesting that the electron transfer (ET) occurs within a diprotein complex. The intramolecular ET rate constants in the diprotein complex increased with increasing the number of DTPA ions. The reactions of native ferrylMb and ferrylMbDTPA with cyt c(II) obeyed a second-order rate law. A possible ET mechanism is proposed; cyt c(II) binds the DTPA-linked anionic patch around Lys87, Lys145, and Lys147 region of ferrylMb(DTPA)n.

Disruption of insulin receptor substrate 2 causes type 2 diabetes because of liver insulin resistance and lack of compensatory beta-cell hyperplasia

To investigate the role of insulin receptor substrate (IRS)-2 in vivo, we generated IRS-2-deficient mice by gene targeting. Although homozygous IRS-2-deficient mice (IRS-2-/- mice) had a body weight similar to wild-type mice, they progressively developed type 2 diabetes at 10 weeks. IRS-2-/- mice showed insulin resistance and a defect in the insulin-stimulated signaling pathway in liver but not in skeletal muscle. Despite insulin resistance, the amount of beta-cells was reduced to 83% of that in wild-type mice, which was in marked contrast to the 85% increase in the amount of beta-cells in IRS-1-deficient mice (IRS-1-/- mice) to compensate for insulin resistance. Thus, IRS-2 plays a crucial role in the regulation of beta-cell mass. On the other hand, insulin secretion by the same number of cells in response to glucose measured ex vivo was significantly increased in IRS-2-/- mice compared with wild-type mice but was decreased in IRS-1-/- mice. These results suggest that IRS-1 and IRS-2 may play different roles in the regulation of beta-cell mass and the function of individual beta-cells.

A retrospective analysis of 88 patients with pancreaticogastrostomy after pancreaticoduodenectomy

BACKGROUND/AIMS

Recently, pancreaticogastrostomy after pancreaticoduodenectomy has been reintroduced as a useful procedure with a low incidence of pancreatic leakage. We decided to retrospectively analyze the early postoperative and late follow-up complications in a large number of patients who had undergone our improved pancreaticogastrostomy.

METHODOLOGY

Between August 1993 and November 1998, we performed pancreaticogastrostomy following pancreaticoduodenectomy in 88 consecutive patients including pylorus preservation in 14. Our pancreaticogastrostomy used a two-layer implantation method using a pancreatic duct stent with an anterior gastrotomy.

RESULTS

The morbidity and mortality rates were 5.7% and 0%, respectively. There were no cases of pancreatic leakage and no postoperative complications directly related to the pancreaticogastrostomy. As for gastric emptying, the average time until resumption feeding was 12 days, with no significant difference between pancreaticogastrostomy and pylorus-preserving pancreaticogastrostomy. As to late follow-up complications, diabetes developed postoperatively in 6.5% (4/62) patients, and of 14 patients who were shown by magnetic resonance cholangiopancreatography, 5 (35.7%) developed pancreatic ductal dilatation after surgery.

CONCLUSIONS

These results from a relatively large group conclusively prove the safety of pancreaticogastrostomy and indicate that the follow-up quality of life is good under the circumstances.

[Binocular function of intermittent exotropia before and after surgery]

PURPOSE

We examined the binocular function of intermittent exotropia before and after surgery, and studied the effect of the surgery and the factor that might be involved in its result.

MATERIALS AND METHODS

402 intermittent exotropic patients, who underwent their first surgical correction for the strabismus at Teikyo University Hospital, were examined for retinal correspondence and stereo acuity before and after surgery.

RESULTS

367 patients (91.3%) had already had good stereo acuity before surgery when their eyes were straight. Regarding retinal correspondence, though 192 patients (47.8%) were abnormal (dual) before surgery, 301 patients (74.9%) were normal after surgery. The eye deviation of 101 patients who could not get normal retinal correspondence after surgery was significantly larger than normal (p < 0.001), and 77.2% of them had also vertical strabismus which was mainly composed of dissociated vertical deviation.

CONCLUSION

Normal binocular function could be recovered by surgical treatment in most intermittent exotropic patients. When patients could not get normal retinal correspondence after surgery, we supposed that dissociated vertical deviation might exert an important effect upon their binocular function.

Mitogenic activity of gelatin to murine spleen cells

We reported previously that gelatin stimulates the growth of spleen cells in vitro. Tritium thymidine (3H-TdR) uptake into phytohemagglutinin (PHA)-stimulated spleen cells as well as intact spleen cells was augmented by gelatin. These findings suggest that gelatin serves as a mitogen for lymphoid cells. In this study, the target of action of gelatin was investigated. Tritium thymidine uptake into T cell-rich fraction was enhanced by incubation with 7.5 mg/ml of gelatin for 48 hours. The level of 3H-TdR uptake into B cell-rich fraction was not definitely increased by gelatin. Flow cytometric analysis confirmed these findings. Namely, it showed that treatment of spleen cells with 7.5 mg/ml gelatin increased a ratio of CD3-positive cells and decreased that of CD19-positive cells. Tritium thymidine uptake into natural killer cell-rich fraction was augmented by gelatin in a similar fashion to T cell-rich fraction. Tritium thymidine uptake into macrophages was very low and not affected by gelatin. Tritium thymidine uptake into macrophage-precursors was very low but was enhanced by gelatin. These findings suggest that gelatin could be used as an agent of cancer biotherapy.

Case of a mentally retarded child with non-24 hour sleep-wake syndrome caused by deficiency of melatonin secretion

A case of a 5-year-old boy with non-24 hour sleep-wake syndrome and mental retardation is reported. His free-running sleep-wake rhythm was remarkably improved by the oral administration of melatonin. The circadian variation in melatonin secretion was extremely low, and circadian rhythm of cortisol secretion was noted. It was speculated that his non-24 hour sleep-wake syndrome was due to a congenital deficiency of melatonin secretion, and supplemental melatonin therapy proved effective for treating his condition.

Pancreaticojejunostomy versus pancreaticogastrostomy in reconstruction following pancreaticoduodenectomy

BACKGROUND

Pancreaticogastrostomy (PG) after pancreaticoduodenectomy has been reported to have a lower incidence of pancreatic fistula than pancreaticojejunostomy (PJ) but this was not confirmed in a recent prospective randomized study.

METHODS

Different methods of reconstruction after pancreaticoduodenectomy were used between January 1994 and January 1999 in two university-affiliated hospitals, PJ (n = 69) in one hospital and PG (n = 73) in the other. Operations at both hospitals were performed by the same surgical team. All pancreatic anastomoses were carried out in two layers with pancreatic duct stents. Pancreatic fistula was identified by the presence of more than 1000 units/l of amylase-rich fluid in the drains 7 days or more after operation, by radiography from the pancreatic duct stent and by water-soluble contrast upper gastrointestinal studies.

RESULTS

The two groups of patients were similar in terms of age, sex, findings at preoperative assessment, disease status, operative time, intraoperative blood loss and nature of non-tumorous pancreatic tissue. The amylase level in ascites at 7 days after operation was significantly lower after PG than PJ (P = 0.032). The incidence of pancreatic fistula in the PG group (zero) was significantly less than that after PJ (13 per cent) (P = 0.014). Intra-abdominal haemorrhage and intra-abdominal abscess occurred in three (4 per cent) and four patients (6 per cent) respectively, with two hospital deaths (3 per cent) in the PJ group, but these complications did not occur after PG.

CONCLUSION

This controlled clinical study supports the hypothesis that PG is safer than PJ, particularly with regard to the incidence of pancreatic fistula.

Insulin receptor substrate-1 in osteoblast is indispensable for maintaining bone turnover

Insulin receptor substrates (IRS-1 and -2) are essential for intracellular signaling by insulin and IGF-I, anabolic regulators of bone metabolism. Mice lacking the IRS-1 gene IRS-1(-/-) showed severe osteopenia with low bone turnover. IRS-1 was expressed in osteoblasts, but not in osteoclasts, of wild-type (WT) mice. IRS-1(-/-) osteoblasts treated with insulin or IGF-I failed to induce tyrosine phosphorylation of cellular proteins, and they showed reduced proliferation and differentiation. Osteoclastogenesis in the coculture of hemopoietic cells and osteoblasts depended on IRS-1 expression in osteoblasts and could not be rescued by IRS-1 expression in hemopoietic cells in the presence of not only IGF-I but also 1,25(OH)(2)D(3). In addition, osteoclast differentiation factor (RANKL/ODF) was not induced by these factors in IRS-1(-/-) osteoblasts. We conclude that IRS-1 deficiency in osteoblasts impairs osteoblast proliferation, differentiation, and support of osteoclastogenesis, resulting in low-turnover osteopenia. Osteoblastic IRS-1 is essential for maintaining bone turnover, because it mediates signaling by IGF-I and insulin and, we propose, also by other factors, such as 1,25(OH)(2)D(3).

A simple preparation of half N-acetylated chitosan highly soluble in water and aqueous organic solvents

A simple and improved method of preparing highly soluble chitosan (half N-acetylated chitosan) was developed using a series of chitosan samples of low molecular weights, and the solubility of the half N-acetylated chitosan in water and organic solvents was investigated in detail. To reduce the molecular weight, chitosan was treated with NaBO3 under the condition that chitosan was homogeneously dissolved in aqueous acetic acid. Weight-average molecular weights of the obtained chitosan samples were determined using a size-exclusion chromatography system equipped with a low-angle laser light-scattering photometer. Each chitosan sample was then N-acetylated with acetic anhydride under the condition that chitosan was homogeneously dissolved in aqueous acetic acid again. The water solubility of the half N-acetylated chitosan thus prepared increased with decreasing molecular weight. From 1H NMR spectroscopy, it was suggested that the sequence of N-acetylglucosamine and glucosamine residues was random. The solubility of the half N-acetylated chitosan of low molecular weight was rather high even in aqueous dimethylacetamide and dimethylsulfoxide.

Multimodality treatment for patients with hepatocellular carcinoma: a single institution retrospective series

BACKGROUND

The main therapeutic options for hepatocellular carcinoma (HCC) are hepatic resection, transcatheter arterial embolization (TAE), percutaneous ethanol injection therapy (PEIT) and regional chemotherapy (RC).

METHODS

This study retrospectively examined the results of primary treatment of 600 patients with hepatocellular carcinoma selected according to the treatment guidelines of our facility and the results of various combination therapies for recurrent cases. The selection criteria of therapeutic options included the number and size of tumours and hepatic function.

RESULTS

The selected primary treatment was hepatic resection for 53.7% of the cases, TAE for 31.5%, PEIT for 8.2% and RC for 6.6%,. The treatment for post-resection recurrence was TAE alone for 62.4% of the cases, TAE + RC for 4.0%, PEIT for 15.2%, TAE + PEIT alone for 4.8%, RC for 8.0% and hepatic resection for 5.6%. The treatment for post-TAE recurrence was TAE alone for 83% of the cases, TAE + PEIT for 9%, TAE + RC for 3%, RC alone for 3% and PEIT alone for 2%. For post-PEIT, therapy was PEIT alone for 71.4% of the cases and PEIT + TAE for 28.6%. For post-RC, RC alone was used for 92.5% and RC + PEIT for 7.5%. The cumulative 3 and 5-year survival rates were 84.4% and 70.6%, respectively for stage I; 61.5% and 48.6% for stage II; 52.7% and 20.5% for stage III; and 22.8% and 17.1% for stage IVA. The cumulative 5 and 7-year survival rates after the primary treatments were 52.% and 40.1%, respectively, for hepatic resection; 46.5% and 38.7%, for TAE; 49.6% and 33.1% for PEIT; and 16.7% and 8.3% for RC.

CONCLUSIONS

To improve the treatment results for HCC, early detection is essential and various modalities of treatments in combination should be used for recurrence after primary treatment.

Effect of hemostatics used during operations for digestive organ on cancer cells present in the peritoneal cavity

We investigated effects of hemostatics used during operations for digestive organ on cancer cells present in the peritoneal cavity using BALB/c mice inoculated with Meth A tumor cells (fibrosarcoma) intraperitoneally (i.p.) and C3H/He mice inoculated with MH134 tumor cell (hepatic cell carcinoma) i.p. Microfibrillar collagen hemostat (Avitene) or fibrinogen preparation (Beriplast P) did not affect survivals of those tumor-bearing mice. Gelatin sponge (Spongel)prolonged survivals of MH134 tumor-bearing mice. Liquid form gelatin used instead of Spongel displayed in vitro antitumor effect on MH134 tumor cells at the concentration of 15 mg/ml. Radioactive sodium chromate-labeled MH134 and Meth A tumor cells were not lysed when they were incubated with 15 mg/ml of liquid form gelatin for 24 hours. On the other hand, the tritium thymidine (3H-TdR) uptake by MH134 or RL male 1 tumor cells was suppressed when they were incubated with 15 mg/ml of liquid form gelatin for 24 hours. Proliferation of Meth A tumor cells were not affected by the treatment. Effect of liquid form gelatin on phytohemagglutinin (PHA)-stimulated spleen cells as a benign counter-part of RL male 1 tumor cells (T cell lymphoma) was examined. Liquid form gelatin (15 mg/ml) did not suppress 3H-TdR uptake by PHA-stimulated spleen cells.

Involvement of nuclear receptor coactivator SRC-1 in estrogen-dependent cell growth of MCF-7 cells

Steroid hormones regulate cell growth and function through the transcriptional control of target genes by their cognate nuclear receptors. These receptors bind to ligands and associate with transcriptional cofactors to stimulate transcription. SRC-1, one of the nuclear receptor coactivators, is known to interact with nuclear receptors and enhance transactivation function in a ligand-dependent manner. In this study, to assess the function of SRC-1 in cell growth regulated by nuclear receptor ligands, we established a stable transformant cell line overexpressing human SRC-1 and studied the action of 17beta-estradiol (E(2)) on cell growth as well as the expression of E(2)-responsive genes in MCF-7 cells. We found that SRC-1 overexpression potentiates cell growth stimulated by E(2) in accordance with enhancement of transcriptional activation of exogenous and endogenous E(2)-responsive genes. These findings clearly indicate the importance of nuclear receptor coactivators for the activities of steroid/lipophilic vitamins in cell growth and gene expression.

Insulin effect during embryogenesis determines fetal growth: a possible molecular link between birth weight and susceptibility to type 2 diabetes

Low birth weight has been reported to be associated with impaired insulin secretion and insulin resistance. It has been proposed that this association results from fetal programming in response to the intrauterine environment (the thrifty phenotype hypothesis). To elucidate the relationship between birth weight and genetically determined defects in insulin secretion, we measured the birth weights of neonates derived from crosses of male pancreatic beta-cell type glucokinase knockout (Gck+/-) mice and female wild-type (WT) or Gck+/- mice. In 135 offspring, birth weights were lower in the presence of a fetal heterozygous mutation and higher in the presence of a maternal heterozygous mutation. Moreover, Gck-/- neonates had significantly smaller birth weights than WT or Gck+/- neonates (means +/- SE 1.49+/-0.03 [n = 30] vs. 1.63+/-0.03 [n = 30] or 1.63+/-0.02 [n = 50] g, respectively; P<0.01). Thus, Gck mutations in beta-cells may impair insulin response to glucose and alter intrauterine growth as well as glucose metabolism after birth. This study has confirmed the results of a previous report that human subjects carrying mutations in Gck had reduced birth weights and has provided direct evidence for a link between insulin and fetal growth. Moreover, birth weights were reduced in insulin receptor substrate-1 knockout mice despite normal insulin levels. Taken together, these results suggest that a genetically programmed insulin effect during embryogenesis determines fetal growth and provides a possible molecular link between birth weight and susceptibility to type 2 diabetes.

Proteomic approach to the identification of cell membrane proteins

The expression of plasma membrane proteins in human monocyte-derived U937 cells was examined by cell disruption and isolation of microsomal fractions. Two alternative procedures for cell disruption, Dounce homogenization and nitrogen cavitation, were compared. Cell homogenization and sequential centrifugation resulted in an approximately fivefold enrichment of plasma membrane proteins in the microsomal fraction. However, identification of 30 such apparently enriched proteins by two-dimensional (2-D) electrophoresis, proteolytic digestion, and mass spectrometry revealed that only eight were plasma membrane proteins, the remaining 22 being contaminants. In contrast, nitrogen cavitation followed by sequential centrifugation and solubilization of proteins with sodium dodecyl sulfate (SDS) and 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate (CHAPS) detergent yielded subcellular fractions, including microsomes, that showed little overlap in constituent proteins as revealed by 2-D electrophoresis. These results highlight the importance of obtaining pure plasma membranes and complete solubilization of membrane proteins for proteomic analysis.

Retrospective analysis of type of hepatic resection for hepatocellular carcinoma

BACKGROUND

Hepatic resection for hepatocellular carcinoma is now considered a relatively safe procedure, owing to refined surgical techniques and management.

METHODS

Three hundred different types of hepatic resection performed in one hospital were reviewed retrospectively. The operative morbidity and mortality rates and long-term survival were assessed.

RESULTS

Tumours were extirpated by lobectomy or extended lobectomy in 48 patients, by segmentectomy in 53, by subsegmentectomy in 94 and by partial resection in 105. The overall hospital mortality rate was 4 per cent (13 of 300). No operative death occurred after lobectomy or extended lobectomy. Segmentectomy and subsegmentectomy were associated with high postoperative complication and hospital mortality rates. There was a significant difference in survival rate between patients with and without a cancer-free surgical margin of more than 1.0 cm. The overall 5- and 9-year survival rates were 51 and 9 per cent respectively. Rates were 56 and 24 per cent for lobectomy or extended lobectomy.

CONCLUSION

For tumours of 2.1 cm or more in size lobectomy appears to carry the least risk of postoperative complications and death in hospital and best achieves a cancer-free surgical margin.

Mutation induction and RBE of low energy neutrons in V79 cells

We have examined the neutron energy dependency of cell killing and mutation induction at the hprt locus in Chinese hamster V79 cells. Monoenergetic neutrons at 0.32, 0.57, and 1.2 MeV were generated at the Hiroshima University Radiobiological Research Accelerator (HIRRAC) Facility, and were used to irradiate cells. The variation in RBE with neutron energy for the end points of cell survival and hprt mutation induction was observed. When compared to 137Cs gamma-rays, all neutron energies were more effective at both cell killing and induction of mutation. Over the range of the neutron energies examined, we found that cytotoxicity increased as the energy decreased from 1.2 to 0.32 MeV. In comparison to gamma-rays, RBEs for cell lethality at 10% survival were 5.7, 6.7, and 7.6 for 1.2, 0.57, and 0.32 MeV, respectively. Mutation induction, on the other hand, was highest at 0.57 MeV with a gradual decrease at 1.2 and 0.32 MeV. RBEs for mutation induction were 9.7, 19.4, and 13.9 for 1.2, 0.57, and 0.32 MeV neutrons. We isolated independent V79 cell mutants at the hprt locus from untreated and neutron-exposed cells and determined the genetic changes underlying the mutation by multiplex polymerase chain reaction (PCR)-based exon deletion analysis. Preliminary results are suggestive of a specific relationship between deletion pattern and neutron energy.

Beta(2)-microglobulin identified as an apoptosis-inducing factor and its characterization

Major histocompatibility complex (MHC) molecules play an important role in antigen presentation for induction of tumor as well as cellular and humoral immunities. Recent studies using anti-MHC antibodies demonstrated that antibodies specific for HLA class I molecules induced cellular activation and a type of apoptosis that may be distinct from Fas-dependent or TNFR (tumor necrosis factor-alpha receptor)-dependent processes. We purified a previously untested apoptosis-inducing factor from HL-60 human leukemic cell-conditioned media to homogeneity and sequenced it. It was identified as beta(2)-microglobulin (beta(2)m), which has been previously known as thymotaxin and is a part of the HLA class I antigen complex. beta(2)m acts on both T-leukemic cells and myeloid leukemic cells to induce apoptosis, which then activates caspase 1 and 3. Cross-linking studies showed that biotinilated beta(2)m recognized an epitope distinct from those recognized by the anti-HLA class I antibody, as reported previously. We demonstrated that beta(2)m plays a previously unrecognized and important role in regulating the elimination of tumor cells, which occurs as a result of the action of beta(2)m as an apoptosis-inducing factor.

PPAR gamma mediates high-fat diet-induced adipocyte hypertrophy and insulin resistance

Agonist-induced activation of peroxisome proliferator-activated receptor gamma (PPAR gamma) is known to cause adipocyte differentiation and insulin sensitivity. The biological role of PPAR gamma was investigated by gene targeting. Homozygous PPAR gamma-deficient embryos died at 10.5-11.5 dpc due to placental dysfunction. Quite unexpectedly, heterozygous PPAR gamma-deficient mice were protected from the development of insulin resistance due to adipocyte hypertrophy under a high-fat diet. These phenotypes were abrogated by PPAR gamma agonist treatment. Heterozygous PPAR gamma-deficient mice showed overexpression and hypersecretion of leptin despite the smaller size of adipocytes and decreased fat mass, which may explain these phenotypes at least in part. This study reveals a hitherto unpredicted role for PPAR gamma in high-fat diet-induced obesity due to adipocyte hypertrophy and insulin resistance, which requires both alleles of PPAR gamma.

Regulation of dopamine uptake by basic fibroblast growth factor and epidermal growth factor in cultured rat astrocytes

We examined the characteristics of dopamine (DA) uptake and its regulation by neurotrophic factors such as basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) in cultured rat astrocytes. In the presence of inhibitors of monoamine oxidase (MAO) and catechol-O-methyl-transferase (COMT), astrocytes took up DA by Na(+)-dependent and Na(+)-independent mechanisms that were sensitive to a reduction in temperature. The Na(+)-dependent and Na(+)-independent components increased linearly with increasing [3H]DA concentration (1-1000 microM), and showed no saturation. Na(+)-dependent DA uptake was significantly inhibited by ouabain, a Na(+)-K+ ATPase inhibitor. In bFGF-treated astrocytes, [3H]DA uptake increased in a time-dependent manner until 48 h, and declined after 72 h in both the presence and absence of Na+. In EGF-treated astrocytes, [3H]DA uptake increased in a time-dependent manner until 72 h in both the presence and absence of Na +. This enhancement of DA uptake induced by EGF or bFGF was significantly inhibited when the cells were cultured with actinomycin D, cycloheximide, or brefeldin A. Actinomycin D and brefeldin A also significantly inhibited the basal uptake of [3H]DA into astrocytes. These results suggest the existence of Na(+)-dependent and Na(+)-independent DA uptake in cultured rat astrocytes, and that EGF or bFGF might stimulate the expression and translocation of the extraneuronal DA transporter.

Computerized tomography nephroscopic images of renal pelvic carcinoma

PURPOSE

Computerized tomography (CT) endoscopy is an interactive 3-dimensional image acquired by helical CT. We assess the usefulness of CT nephroscopy in the diagnosis of renal pelvic cancers.

MATERIALS AND METHODS

Surface rendering CT nephroscopy was performed after intravenous administration of contrast agent and furosemide in 32 patients with suspected renal pelvic carcinoma. Retrospective review revealed that 23 patients later underwent nephroureterectomy. Two observers blinded to the pathology results independently reviewed the CT nephroscopic and axial CT images of the 23 patients to localize pelvic tumors and to determine the extent of the disease. The CT nephroscopic and axial CT images were correlated with the pathological findings.

RESULTS

Pathological examination revealed 4 polypoid, 6 pedunculated, 7 sessile, 1 sessile with ulceration and 6 infiltrating renal pelvic carcinomas in the 23 patients. CT nephroscopy revealed 22 carcinomas (92%) and CT demonstrated 20 (83%). CT nephroscopy was superior to axial CT in detecting 4 pedunculated and 3 infiltrating carcinomas but failed to detect 1 sessile carcinoma which completely replaced the upper portion of a double renal pelvis and 1 polypoid tumor associated with infiltrating carcinoma. The CT nephroscopic images correlated well with pathological findings.

CONCLUSIONS

CT nephroscopy is useful to visualize the complex morphology of renal pelvic carcinomas noninvasively and is superior to axial CT for the detection of infiltrating and pedunculated carcinomas.