Innovative use of magnetic resonance imaging-guided focused ultrasound surgery for non-invasive breast cancer: a report of two cases

Objective

This report describes the first clinical experience with magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS) using the ExAblate 2100 system for non-invasive breast cancer.

Methods

Two women with non-invasive breast cancer underwent MRgFUS treatment. One week after the MRgFUS treatment, US-guided vacuum-assisted biopsy was performed for the ablated lesions at the same time as breast-conserving surgery.

Results

The patients experienced good cosmetic outcomes and did not experience any severe adverse events, such as skin burns. Pathological examination of the surgical specimens revealed a few degenerated intraductal lesions around the breast biopsy markers.

Conclusion

Performing MRgFUS with the new ExAblate 2100 system appears to be safe and feasible. The histopathological results revealed that adequate ultrasound energy in the appropriate location can induce tumor necrosis.

Liquid biopsy for the detection of clinical biomarkers in early breast cancer: new insights and challenges

The widespread use of breast screening programs has contributed to the detection of early stage breast cancer, which is often asymptomatic. Early diagnosis is essential to avoid overtreatment and improve clinical outcomes, as early stage breast cancer is rarely life-threatening if detected quickly. Despite this, tissue biopsy remains the principle method for detecting these cancers. Liquid biopsy has been recently proposed as a promising detection method in oncology that is not only less invasive but also contributes to the early diagnosis of breast cancer. Here, we describe the clinical utility of liquid biopsy as a tool for the early detection of breast cancer.

Reactive ION Beam Etching of GaN Grown By Movpe

A dry etch technique using Cl2 based reactive ion beam etching (RIBE) has been developd for GaN-based semiconductor lasers. The etching rate of 350 − 1000 Å/min was obtained. This is applicable for micro fabrication of GaN based materials in the same way as used for other III-V group semiconductors. Furthermore, it is found that the surface damage of GaN layers induced by the RIBE-etch can be removed using ultra-violet assisted wet-etching using alkali solution. The PL intensity of damaged GaN layers is increased after the post-process wet-etching.

Role of urotensin II gene in genetic susceptibility to Type 2 diabetes mellitus in Japanese subjects

AIM/HYPOTHESIS

Urotensin II is a potent vasoactive hormone and the urotensin II gene (UTS2) is localized to 1p36-p32, one of the regions reported to show possible linkage with Type 2 diabetes in Japanese subjects. The aim of this study is to investigate a possible contribution of SNPs in the UTS2 gene to the development of Type 2 diabetes.

METHODS

We surveyed SNPs in the UTS2 gene in 152 Japanese subjects with Type 2 diabetes mellitus and two control Japanese cohorts: one consisting of 122 elderly subjects who met stringent criteria for being non-diabetic, including being older than 60 years of age with no evidence of diabetes (HbA(1c)<5.6%), and another 268 subjects with normal glucose tolerance.

RESULTS

We identified two SNPs with amino acid substitutions, designated T21M and S89N. The allele frequency of 89N was higher in Type 2 diabetic patients than in both elderly normal subjects (p=0.0018) and subjects with normal glucose tolerance (p=0.0011), whereas the allele frequency of T21M was essentially identical in these three groups. Furthermore, in the subjects with normal glucose tolerance, 89N was associated with higher insulin concentrations on oral glucose tolerance test, suggesting reduced insulin sensitivity in subjects with 89N.

CONCLUSION/INTERPRETATION

These results strongly suggest that the S89N polymorphism in the UTS2 gene is associated with the development of Type 2 diabetes, via insulin sensitivity, in Japanese subjects.

Troglitazone treatment increases plasma vascular endothelial growth factor in diabetic patients and its mRNA in 3T3-L1 adipocytes

Troglitazone is one of the thiazolidinediones, a new class of oral antidiabetic compounds that are ligands of peroxisome proliferator-activated receptor-gamma. This study on vascular endothelial growth factor (VEGF), also known as vascular permeability factor, was prompted by our clinical observation that the characteristics of troglitazone-induced edema were very similar to those caused by vascular hyperpermeability. When Japanese diabetic patients were screened for plasma VEGF, we found levels to be significantly (P < 0.001) increased in troglitazone-treated subjects (120.1 +/- 135.0 pg/ml, n = 30) compared with those treated with diet alone (29.2 +/- 36.1 pg/ml, n = 10), sulfonylurea (25.8 +/- 22.2 pg/ml, n = 10), or insulin (24.6 +/- 19.0 pg/ml, n = 10). Involvement of troglitazone in increased VEGF levels was further supported by the plasma VEGF levels in five patients before treatment (20.2 +/- 7.0 pg/ml), after 3 months of troglitazone treatment (83.6 +/- 65.9 pg/ml), and 3 months after discontinuation (28.0 +/- 11.6 pg/ml). We further demonstrated that troglitazone, as well as rosiglitazone, at the plasma concentrations observed in patients, increased VEGF mRNA levels in 3T3-L1 adipocytes. VEGF is an angiogenic and mitogenic factor and is currently considered the most likely cause of neovascularization and hyperpermeability in diabetic proliferative retinopathy. Although increased VEGF may be beneficial for subjects with macroangiopathy and troglitazone is currently not available for clinical use, vascular complications, especially diabetic retinopathy, must be followed with great caution in subjects treated with thiazolidinediones.

The Pro12 -->Ala substitution in PPAR-gamma is associated with resistance to development of diabetes in the general population: possible involvement in impairment of insulin secretion in individuals with type 2 diabetes

The allele frequencies for a Pro12-->Ala substitution in peroxisome proliferator-activated receptor-gamma differ among ethnic groups, and its relationship with diabetes and associated diseases is controversial. The prevalence of this polymorphism and its effects on clinical characteristics have now been evaluated with a large number of Japanese individuals with type 2 diabetes (n = 2,201) and normal control subjects (n = 1,212) recruited by 10 institutions located in seven different cities in Japan. The allele frequency for the Ala12 variant was significantly lower in the type 2 diabetic group than in the control group (2.39 vs. 4.13%, P = 0.000054). However, compared with subjects without the Ala12 variant, the diabetic subjects with this variant exhibited a significantly higher serum concentration of total cholesterol (P = 0.001), manifested a reduced capacity for insulin secretion as evaluated by homeostasis model assessment (P = 0.007), and tended to possess a higher level of HbA1c. These data suggest that the Ala12 variant is associated with a reduced risk for the development of diabetes in the general population, but that it may be also a risk factor for insulin deficiency and disease severity in individuals with type 2 diabetes.

Coexistence of chronic myelogenous leukemia and multiple myeloma. Case report and review of the literature

A case report of simultaneous presentation of chronic myelogenous leukemia (CML) and multiple myeloma (MM) in a 72-year-old female is described. Our case was typical of Ph1-positive and chimeric bcr-abl messenger RNA-positive CML. Furthermore, a marked IgG (kappa-type) paraproteinemia was present. Fluorescence in situ hybridization showed that 97% of marrow nucleated cells were positive for bcr-abl fusion signal, when myeloma cells in the bone marrow amounted to 19.0%. In the literature survey, 4 similar cases with coexistence of CML and MM have been identified.

Overexpression of dominant negative mutant hepatocyte nuclear factor (HNF)-1alpha inhibits arginine-induced insulin secretion in MIN6 cells

AIMS/HYPOTHESIS

To explain the mechanisms whereby mutations in the HNF-1alpha gene cause insulin secretory defects.

METHODS

A truncated mutant HNF-1alpha (HNF-1alpha288t) was overexpressed in hepatoma cells (HepG2) and murine insulinoma cells (MIN6) using a recombinant adenovirus system and expression of the HNF-1alpha target genes and insulin secretion were examined.

RESULTS

Expression of phenylalanine hydroxylase and alpha1-antitrypsin genes, the target genes of HNF-1alpha, was suppressed in HepG2 cells by overexpression of HNF-1alpha288t. In MIN6 cells, overexpression of HNF-1alpha288t did not change insulin secretion stimulated by glucose (5 mmol/l and 25 mmol/l) or leucine (20 mmol/l). Potentiation of insulin secretion by arginine (20 mmol/l, in the presence of 5 mmol/l or 25mmol/l glucose) was, however, reduced (p < 0.0001 and p = 0.027, respectively). Similarly reduced responses were observed when stimulated with homoarginine. Expression of the cationic amino acid transporter-2 was not reduced and insulin secretory response to membrane depolarization by 50 mmol/l KCl was intact.

CONCLUSION/INTERPRETATION

The HNF-1alpha288 t, which is structurally similar to the mutant HNF-1alpha expressed from the common MODY3 allele, P291fsinsC, exerts a dominant negative effect. Suppression of HNF-1alpha in MIN6 cells severely impaired potentiation of insulin secretion by arginine, whereas glucose-stimulated and leucine-stimulated insulin secretion was intact. Our findings delineate the complex nature of beta-cell failure in patients with MODY3. This cell model will be useful for further investigation of the mechanism of insulin secretory defects in these patients.

Granulocyte colony-stimulating factor (G-CSF) dependent hematopoiesis with monosomy 7 in a patient with severe aplastic anemia after ATG/CsA/G-CSF combined therapy

We report a case of secondary myelodysplastic syndrome (MDS) with monosomy 7, which evolved from severe aplastic anemia (SAA) after long-term use of granulocyte colony-stimulating factor (G-CSF). A 36 year old female was admitted for detailed examination and treatment of pancytopenia. SAA was diagnosed based on hypoplastic bone marrow and a normal chromosome study. She was treated with anti-thymocyte globulin (ATG), ciclosporin A (CsA) and G-CSF, which resulted in gradual improvement of not only the myeloid but also the erythroid-megakaryocyte series. However, bone marrow dysplasia with monosomy 7 was observed after 7 months of a combination therapy of immunosuppressant and G-CSF, which prompted the discontinuation of G-CSF administration. Thereafter, bone marrow hypoplasia gradually progressed, resulting in a second aplastic crisis. During this process, the proportion of marrow cells showing monosomy 7 decreased, and the proportion with normal karyotype increased. Re-administration of G-CSF induced a trilineage, though dysplastic, hematological response; but the monosomy 7 positive population increased again. These observations indicated the presence of G-CSF dependent hematopoiesis associated with monosomy 7 in this patient. Although many G-CSF related MDS/AML cases with this leukemia-specific abnormal karyotype have been reported with emphasis on the harmful effects of G-CSF, G-CSF was useful even after the appearance of monosomy 7 as a means of avoiding life-threatening infection in this patient.

Overexpression of mitochondrial FAD-linked glycerol-3-phosphate dehydrogenase does not correct glucose-stimulated insulin secretion from diabetic GK rat pancreatic islets

Glucose-stimulated insulin secretion is impaired in GK (Goto-Kakizaki) rats, perhaps because of abnormalities in glucose metabolism in pancreatic islet beta cells. The glycerol phosphate shuttle plays a major role in glucose metabolism by reoxidizing cytosolic NADH generated by glycolysis. In the pancreatic islets of GK rats, the activity of mitochondrial FAD-linked glycerol-3-phosphate dehydrogenase (mGPDH), the key enzyme of the glycerol phosphate shuttle, is decreased and this abnormality may be responsible, at least in part, for impaired glucose-stimulated insulin secretion. To investigate this possibility, we overexpressed mGPDH in islets isolated from GK rats via recombinant adenovirus-mediated gene transduction, and examined glucose-stimulated insulin secretion. In islets isolated from diabetic GK rats at 8 to 10 weeks of age, glucose-stimulated insulin secretion was severely impaired, and mGPDH activity was decreased to 79 % of that in non-diabetic Wistar rats. When mGPDH was overexpressed in islets from GK rats, enzyme activity and protein content increased 2- and 6-fold, respectively. Basal (3 mmol/l glucose) and glucose-stimulated (20 mmol/l) insulin secretion from the Adex1CAlacZ-infected GK rat islets were, respectively, 4.4 +/- 0.7 and 8.1 +/- 0.7 ng. x islet(-1) x 30 min(-1), and those from mGPDH-overexpressed GK rat islets 4.7 +/- 0.3 and 9.1 +/- 0.8 ng x islet(-1) x 30 min(-1), in contrast to those from the AdexlCAlacZ-infected non-diabetic Wistar rat islets (4.7 +/- 1.6 and 47.6 +/- 11.9 ng x islet(-1) x 30 min(-1)). Thus, glucose-stimulated insulin secretion is severely impaired in GK rats even in the stage when mGPDH activity is modestly decreased, and at this stage, overexpression of mGPDH cannot restore glucose-stimulated insulin secretion. We conclude that decreased mGPDH activity in GK rat islets is not the defect primarily responsible for impaired glucose-stimulated insulin secretion.

Identification and functional analysis of sulfonylurea receptor 1 variants in Japanese patients with NIDDM

The sulfonylurea receptor 1 (SUR1) is an essential regulatory subunit of the beta-cell ATP-sensitive K+ channel (K[ATP]). The possible role of SUR1 gene mutation(s) in the development of NIDDM remains controversial as both a positive association and negative linkage results have been reported. Therefore, we examined the SUR1 gene at the single nucleotide level with single strand conformation polymorphism analysis in 100 Japanese NIDDM patients. We identified a total of five amino acid substitutions and 17 silent mutations by examining all 39 exons of this gene. Two rare novel mutations, D811N in exon 20 and R835C in exon 21, were identified in the first nucleotide-binding fold (NBF), a functionally important region of SUR1, in one patient each, both heterozygotes. To analyze possible functional alterations, we reconstituted the mutant K(ATP) by coexpressing beta-cell inward rectifier (BIR) (Kir 6.2), a channel subunit of K(ATP), and mutant SUR1 in HEK293T and COS-7 cells. As demonstrated by the patch clamp technique and rubidium (Rb+) efflux studies, neither mutation alters the properties of channel activities. Two other rare missense mutations, R275Q in exon 6 and V560M in exon 12, were also identified. The R275Q substitution was not found in 67 control subjects, and V560M was present in three control subjects. Neither of these substitutions appeared to cosegregate with NIDDM in the probands' families. A previously reported S1370A substitution located in the second NBF was also common in the Japanese subjects (allelic frequency 0.37), and was found at an equal frequency in nondiabetic control subjects. In conclusion, SUR1 mutations impairing K(ATP) function do not appear to be major determinants of NIDDM susceptibility in Japanese.

Isolation of full-length cDNA of mouse PAX4 gene and identification of its human homologue

Recent genetic studies have suggested that PAX4, a member of the paired box (PAX) gene family, is involved in the mechanism regulating the fate of pancreatic islet endocrine progenitor cells. Murine PAX4 was originally identified by genomic screening and, to date, only a partial sequence of PAX4 has been reported. In this study, we cloned the full-length cDNA of mouse PAX4 by RACE (rapid amplification of cDNA ends) using RNA from MIN6 cells, a mouse insulinoma cell line. The full length of cDNA was 1.38 kb, consistent with the estimated size of the transcript by Northern blot. The deduced mouse PAX4 protein was 349 amino acids and had the predicted molecular weight of 38 kDa. Two DNA binding motifs, a 128-amino acid paired domain and a 61-amino acid paired-type homeodomain exhibit the highest amino acid homology with PAX6 (71.2%, 65.0%, respectively), another member of the PAX gene family. However, the sequence of the C-terminal segment of PAX4 diverged and showed no significant homology with any other known PAX genes. As to the genomic DNA, the coding region of the mouse PAX4 gene spanned approximately 5.5 kb and was composed of 10 exons. In the public DNA database, a human cosmid (g1572c264), which was localized on human chromosome 7q31.3, was found to contain a gene homologous to PAX4. The nucleotide and protein sequence homologies between mouse PAX4 and its human homologue were 83.1% and 80.0%, respectively. Interestingly, the ARP5 (ADP-ribosylation factor 5) gene was also found in the same cosmid g1572c264, suggesting the ARP5 gene to be adjacent to the human PAX4 homologue. The human cosmid g1572c264 contains at least four SSRPs (simple sequence repeat polymorphism), which could be used for genetic linkage studies of the locus. The results of this study, i.e. isolation of the full-length cDNA sequence of PAX4 and identification of the homologous human gene, will facilitate further functional and genetic studies of the PAX4 gene.

Leptin induces proliferation of pancreatic beta cell line MIN6 through activation of mitogen-activated protein kinase

Leptin at 1-5 nM, the concentrations observed in obese subjects, caused an increase in the active form of mitogen-activated protein kinase (MAPK) that was accompanied by increased tyrosine phosphorylation of STAT-1 and STAT-3 in a mouse pancreatic beta cell line, MIN6. Leptin also increased DNA synthesis and cell viability in MIN6 cells based on the results of [3H]-thymidine incorporation and colorimetric MTT assay, respectively. The specific MAPK-inhibitor PD98059 blocked not only the MAPK activation but also the increment in DNA synthesis and cell viability caused by leptin. Thus, leptin stimulates both the MAPK and the Janus kinase (JAK)-STAT cascade as well as inducing proliferation through the MAPK cascade in MIN6 cells. This mechanism might account, at least in part, for obesity-induced pancreatic islet hypertrophy.

Detection of variants in the mitochondrial glycerophosphate dehydrogenase gene in Japanese NIDDM patients

Mitochondrial FAD-linked glycerophosphate dehydrogenase (mGPDH) is thought to be an important factor for glucose sensing in pancreatic beta cells. To evaluate the significance of the mGPDH gene in the development of non-insulin-dependent diabetes mellitus (NIDDM), we set up primers and conditions for polymerase chain reaction (PCR) amplification of the coding exons and flanking regions. Screening of 100 Japanese NIDDM patients for mutations using the PCR-single strand conformation polymorphism (SSCP) method revealed four variants (ACA:Thr243-ACG:Thr243, CAT:His264-CGT:Arg264, GCA:Ala305-GCC:Ala305, GCA:Ala 306-TCA:Ser306). The His264-Arg264 variant was found in 36 patients, while the other variants were found in only one patient each. Neither the genotypic (chi 2 = 3.15, p = 0.21) nor the allelic (chi 2 = 2.27, p = 0.13) frequency of the His264-Arg264 mutation differed between 253 Japanese NIDDM patients and 157 non-diabetic subjects. In addition, in NIDDM patients, neither the treatment modality nor body mass index differed between those with and without this mutation. These results suggest that inherited defects at this locus do not make a major contribution to genetic susceptibility to NIDDM in the Japanese population.

Donor leukocyte transfusions and discontinuation of immunosuppressants to achieve an initial remission after allogeneic bone marrow transplantation in a patient with primary refractory acute leukemia

We present a female patient who received an allogeneic bone marrow transplantation for primary refractory Philadelphia-positive acute biphenotypic leukemia. Since leukemic blasts were persistently present in peripheral blood and bone marrow, in spite of the evidence for engraftment of male donor hematopoiesis, we performed donor leukocyte transfusions and discontinued immunosuppression. An initial complete remission was obtained 15 weeks after allogeneic bone marrow transplantation, and lasted for 24 weeks. We concluded that the prominent mechanism for the eradication of the refractory leukemic clone in the patient was the graft-versus-leukemia effect.

Molecular cloning of human mitochondrial glycerophosphate dehydrogenase gene: genomic structure, chromosomal localization, and existence of a pseudogene

cDNA of mitochondrial glycerophosphate dehydrogenase (mGPDH), a defect of which is a possible cause of non-insulin dependent diabetes mellitus, was cloned from a human insulinoma cDNA library. The deduced amino acid sequence showed 91% and 92% homology with those of rat and mouse mGPDH, respectively. The mGPDH gene was mapped to chromosome 2q23 by FISH analysis. Genomic clones for mGPDH were then isolated using mouse mGPDH cDNA and PCR products of human mGPDH cDNA as probes. Genomic structure was studied by sequencing the exon-intron boundaries and by PCR amplification of intronic regions using genomic clones as templates. The human mGPDH gene was shown to be composed of 15 coding exons, containing a (CA)n repeat region inside the gene, which was not polymorphic in the Japanese population. Genomic cloning also identified a pseudogene located on chromosome 19q13.4. These results provide information useful for analyzing the mGPDH gene in patients with non-insulin dependent diabetes mellitus.

Sequence variations of the pancreatic islet/liver glucose transporter (GLUT2) gene in Japanese subjects with noninsulin dependent diabetes mellitus

To assess the genetic susceptibility to noninsulin-dependent diabetes mellitus (NIDDM) in Japanese subjects, we investigated the role of GLUT2 gene defects in patients with NIDDM. When the allelic frequency of a simple tandem repeat polymorphism in the GLUT2 gene was compared, the allele with 155 base pairs was more common in NIDDM patients (n = 99) than in controls (n = 89; 5.1% vs. 0.6%; P = 0.0118, by Fisher's exact test), whereas this was not significant after the correction for multiple comparisons. To directly identify mutations, we then analyzed each of 11 exons by the polymerase chain reaction-single strand conformation polymorphism analysis in 60 NIDDM patients. We found 2 missense mutations in exon 3: CCC-->CTC (Pro68-->Leu) in 1 patient and ACT-->ATT (Thr110-->Ile) in 3 patients, all in the heterozygous state. These mutations were not found in 60 control subjects. To evaluate the significance of the Pro68-->Leu mutation, the family members of the proband were studied. The mutation did not appear to be associated with the disease or other clinical parameters including change in immunoreactive insulin/change in plasma glucose or oral glucose load. The other mutation (Thr110-->Ile) is known to be functionally insignificant. We identified 4 additional nucleotide changes, all of which appeared to be silent. We concluded that the mutations in the GLUT2 gene were not major determinants of genetic susceptibility to NIDDM in Japanese.

HepG2/erythrocyte glucose transporter (GLUT1) gene in NIDDM: a population association study and molecular scanning in Japanese subjects

To evaluate the role of mutations in the glucose transporter (GLUT1) gene in Japanese patients with non-insulin-dependent diabetes mellitus (NIDDM), we first conducted a population association study using the XbaI polymorphism of the gene. A polymerase chain reaction (PCR)-based assay was developed and used for the analysis. When analysed in 91 diabetic patients and 87 non-diabetic control subjects, the distribution of the genotype frequency was significantly different between the two groups (p = 0.0025). The (-) allele was significantly associated with NIDDM (odds ratio 2.317, 95% confidence interval 1.425-3.768). To identify possible mutation(s) in the GLUT1 gene, which was in linkage disequilibrium with the (-) allele, all ten exons of the gene were analysed by PCR single-strand conformation polymorphism (SSCP) analysis in 53 diabetic patients with at least one (-) allele. Variant SSCP patterns were detected in exons 2, 4, 5, 7, 9 and 10. Sequence analysis revealed that all the variants represented silent mutations. One of the variants in exon 2, GCT (Ala15)-->GCC(Ala), created a HaeIII restriction site. This polymorphism was common in Japanese subjects with heterozygosity of 0.36 and polymorphism information content 0.29. We conclude that the structural mutation of GLUT1 is rare and not likely to be a major genetic determinant of NIDDM in Japanese subjects. The XbaI (-) allele of the GLUT1 gene appeared to be a genetic marker of NIDDM in Japanese subjects. The possibility of the presence of mutation(s) in the regulatory region of the gene or in another locus nearby could not be excluded.

Tolbutamide inhibits glucagon-induced phosphorylation of 6PF-2-K/Fru-2,6-P2ase in rat hepatocytes

In previous studies, we demonstrated that tolbutamide inhibits a phosphorylation of hepatic 6-phosphofructo-2-kinase (6PF-2-K)/fructose-2,6-bisphosphatase (Fru-2,6-P2ase) catalyzed by the adenosine 3',5'-cyclic monophosphate-dependent protein kinase in a reconstruction system using the purified enzyme from the rat liver. In the current study, to assess a role of tolbutamide on hepatic 6PF-2-K/Fru-2,6-P2ase physiologically, we used intact rat hepatocytes and examined effects of tolbutamide on a phosphorylation of the bifunctional enzyme in the presence of glucagon. Glucagon induced a rapid phosphorylation of hepatic 6PF-2-K/Fru-2,6-P2ase accompanied by an inhibition of 6PF-2-K activity and a stimulation of Fru-2,6-P2ase activity in a dose-dependent manner. Tolbutamide inhibited glucagon-induced phosphorylation of the bifunctional enzyme protein in a dose-dependent manner. By adding 2 mM tolbutamide, reduced activity of 6PF-2-K and increased activity of Fru-2,6-P2ase in the presence of 10(-9) M glucagon were partially restored. The present results suggest the possibility that tolbutamide modulates the activity of hepatic 6PF-2-K/Fru-2,6-P2ase through inhibiting a phosphorylation of the enzyme protein. The counterregulatory influence of tolbutamide on the effect of glucagon suggests a possible mechanism for the extrapancreatic effect of sulfonylurea drugs.

[Defects of candidate genes in Japanese NIDDM--glucose transporter gene(GLUT1 gene, GLUT4 gene)]

To assess the contribution of GLUT1 and GLUT4 genes to NIDDM susceptibility in Japanese population, we performed population studies using RFLP markers. We found the strong association between XbaI polymorphism at GLUT1 gene and NIDDM, but no association between KpnI polymorphism at GLUT4 gene and NIDDM. Based on these results, molecular scanning of GLUT1 gene was performed using SSCP and direct sequencing in Japanese population, to substantiate the gene defect predisposing to NDDM. Although silent mutations were found, the meaningful mutations within the coding regions were not demonstrated. Thus the positive association observed in population study may be spurious or due to the abnormalities in non-coding regions such as promoter or other regulatory elements at GLUT1 gene.

Insulin-like effects of vanadate on rat liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase mRNA and protein inductions in diabetic rats

Effects of vanadate on liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (6PF-2-K/F-2,6-P2ase) mRNA and protein inductions were examined in streptozotocin (STZ)-induced diabetic rats. In diabetic rats at one week after STZ (60 mg/kg body weight), the liver 6PF-2-K activity was decreased to 22% of the control. The enzyme protein was also decreased to 31% of the control, but the reduction in mRNA was not significant. Treatment of diabetes with vanadate (10 mg/kg BW, i.v., every 8 h), as well as insulin (10 u/kg BW, s.c., every 8 h), increased the 6PF-2-K activity and the enzyme protein content, though it was not completely restored to the control level. 68% of the control was the figure for enzyme activity and 65% of the control for protein content after 24-h of treatment. On the other hand, vanadate, like insulin, increased enzyme mRNA content to a higher level than the control (140% of the control). The present results indicate that vanadate, like insulin, modulates the liver 6PF-2-K/Fru-2,6-P2ase gene expression, and stimulated protein induction contributes to the regulation of its enzyme activity, resulting in amelioration of the deranged carbohydrate metabolism in the diabetic state.

Polymorphic microsatellite repeat markers at the glucokinase gene locus are positively associated with NIDDM in Japanese

To assess the possible role of glucokinase defects contributing to a genetic susceptibility to NIDDM in Japanese, allelic frequencies of two microsatellite repeat polymorphisms, one in the 3'-flanking region (GCK1) and the other in the 5'-flanking region (GCK2) of the human glucokinase gene, were analyzed in subjects with NIDDM and in nondiabetic control subjects. After typing 107 diabetic and 74 nondiabetic subjects, we found four GCK1 alleles (Z, Z2, Z4, Z6) and six GCK2 alleles (0, -4, -2, 2, 4, 8). The frequency distribution of GCK1 alleles was different between the two groups (P = 0.005), although not significant after correction for multiple comparisons. The Z4 allele was found more frequently in diabetic than in nondiabetic subjects (23 vs. 10%, P = 0.002). This was still significant after correction for multiple comparisons (P < 0.05). The frequency distribution of GCK2 alleles was not different between the two groups. However, the -2 allele was more common in diabetic than in nondiabetic subjects (P = 0.044), although not significant after adjusting for multiple comparisons. Clinical characteristics were compared between the diabetic subjects with Z4 and/or -2 allele and those without either of these two alleles. No differences were found in the age of diagnosis, positive family history, mode of therapy, current HbA1c, or daily urinary C-peptide immunoreactivity excretion between the two groups. We demonstrated a significant association between GCK1 and GCK2 alleles and NIDDM. The results indicate that the polymorphic alleles GCK1 and GCK2 could be genetic markers in NIDDM in Japanese, suggesting a relationship between glucokinase defects and the susceptibility to NIDDM in this population.

Linkage analysis of GLUT1 (HepG2) and GLUT2 (liver/islet) genes in familial NIDDM

Familial NIDDM probably results from combined inherited defects of insulin secretion and action. Members of the facilitative glucose transporter family are strong candidates for both defects, and RFLPs for both GLUT1 (erythrocyte) and GLUT2 (liver/islet) genes have been associated with NIDDM in some populations. To test the hypothesis that GLUT1 and GLUT2 mutations contribute to the inherited predisposition to NIDDM, we examined linkage of these loci with NIDDM in 18 large Utah white pedigrees (two and three generation) ascertained for > or = 2 NIDDM siblings. We used two RFLPs detected with Xba1 and Stu1 for the GLUT1 transporter. For the GLUT2 (liver/beta-cell) transporter gene, we used an RFLP detected with EcoR1 and a highly polymorphic (6-allele) dinucleotide (microsatellite) repeat. Analysis was performed with the MLINK program of the LINKAGE package. We tested four models for each locus: dominant and recessive, with IGT alternately considered as unknown affection status, or affected if IGT was diagnosed < or = 45 yr of age and unknown if > 45 yr. Disease gene frequencies were chosen to give approximate disease prevalence in American whites (q = 0.03, dominant; q = 0.25, recessive). Linkage of GLUT1 and NIDDM was strongly and significantly rejected under all models, with total (pooled) LOD scores of -5.7 to -8.9, indicating > 500,000:1 odds against linkage. Pooled LOD scores were significantly negative (< -2.0, or 100:1 odds against linkage) to a recombination fraction of > 5%. No heterogeneity was apparent. Analysis of GLUT2 gave similar results, with LOD scores of < -4.0 under each model, indicating at least 10,000:1 odds against linkage.(ABSTRACT TRUNCATED AT 250 WORDS)

Human glucokinase gene: isolation, structural characterization, and identification of a microsatellite repeat polymorphism

The gene encoding human glucokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1), a major component of glucose sensing in pancreatic islet beta-cells, was isolated and characterized. The gene was shown by Southern blotting to exist as a single copy in the genome which mapped to chromosome 7p. It contained 12 exons including two tissue-specific first exons, one active in islet beta-cells (1B), and the other active in liver (1H), and one optional cassette exon which was expressed as a minor form in the liver. Thus the three previously reported isoforms of glucokinase mRNA were the result of tissue-specific activation of separate liver and islet promoters and subsequent alternative splicing events. Eleven exons, including 1H and the optional cassette exon 2A, were scattered over 16 kilobase (kb) in the genome, while exon 1B was separated from the rest by at least 20 kb. Although the islet promoter was found to lack a TATA box, a major transcript from the islet promoter was mapped 486 nucleotides upstream of the translation initiation site. The presence in the islet glucokinase promoter of the potential control element GCCACCAG, a homology of the regulatory element present in both human insulin (GCCACCGG) and rat insulin (GCCATCTG) genes, implied a possible tissue-specific regulatory role of this element. The liver promoter was found to contain a TATA box-like sequence, and transcription was initiated predominantly at 168 nucleotides upstream of the translation initiation site of the major isoform. A new highly polymorphic microsatellite, composed of a compound imperfect dinucleotide repeat [GT]15[GA]8CA[GA]7CA[GA]3AA[GA]2, was mapped 6 kb upstream of islet exon 1. A polymerase chain reaction-based assay was developed, and seven different sized alleles were identified in American Blacks. The sequence information reported here, along with the new polymorphic marker, will make it possible to clarify the molecular basis of potential glucokinase defects in noninsulin-dependent diabetes mellitus patients and may further elucidate the nature of genetic susceptibility to the development of this common metabolic disease.

Effects of tolbutamide on fructose-2,6-bisphosphate formation and ketogenesis in hepatocytes from diabetic rats

To assess the extrapancreatic action of sulfonylurea directly in the diabetic, effects of tolbutamide on hepatocyte fructose-2,6-bisphosphate (F-2,6-P2) formation and ketone production were investigated using isolated hepatocytes from streptozotocin (STZ)-induced diabetic rats. The basal level of hepatocyte F-2,6-P2 was significantly higher in diabetic rats within 2 weeks after STZ (40 mg/kg body weight) injection compared with that in the nondiabetic control group. Ultimately, a marked decrease in the F-2,6-P2 level was observed at 4 weeks after STZ administration (10% of the control). Although the addition of tolbutamide further increased the hepatocyte F-2,6-P2 level during the first week after STZ injection, no significant effect was observed after the second week and on from the initial STZ. Treatment of diabetes with insulin restored the stimulatory effect of tolbutamide on the hepatocyte F-2,6-P2 formation. Tolbutamide, independently of insulin treatment, lowered the ketone production of hepatocytes from diabetic rats. The present results indicate that insulin is necessary, in advance, for sulfonylurea to stimulate the liver F-2,6-P2 formation, while tolbutamide inhibition of hepatocyte ketone production is independent of insulin. These results provide further support for the role of sulfonylurea in regulating hepatic energy metabolism in the diabetic.

Mapping the human liver/islet glucose transporter (GLUT2) gene within a genetic linkage map of chromosome 3q using a (CA)n dinucleotide repeat polymorphism and characterization of the polymorphism in three racial groups

The human liver/islet glucose transporter (GLUT2), a candidate gene for diabetes, has been incorporated into a genetic linkage map for chromosome 3q using a (CA)n dinucleotide repeat polymorphism adjacent to the 3'-end of exon 4a. We have found a total of nine alleles ranging in length from 153 to 169 nucleotides in three racial groups and have determined the precise structure of the variable region for four of the alleles by DNA sequencing. Five alleles were found to be common to the American Black, Caucasian, and Pima Indian racial groups studied. One allele (169 bp) was unique to American Blacks, and another rare allele (153 bp) was found only in the Caucasian population studied. Observed heterozygosity of the polymorphism in the Caucasian (CEPH) reference pedigree collection is 60%, for American Blacks 71%, and for Pima Indians 53%. An independent study recently identified the same dinucleotide repeat and found six alleles in a Caucasian population (Froguel et al., 1991), a result that we confirm; however, our sequencing data indicate a different molecular structure for the polymorphism for some of the alleles. We have constructed a new genetic linkage map of chromosome 3q uniquely placing the GLUT2 gene between flanking markers D3S26 and D3S43. The genetic map consists of 23 loci (25 RFLPs and 2 (CA)n dinucleotide repeat markers) with 14 markers uniquely localized with odds of at least 1000:1. Three genes (FTHL4, TF, GLUT2) are integrated into the map, which spans a sex-average distance of 147.3 cM, 103.8 cM in males and 227.0 cM in females.(ABSTRACT TRUNCATED AT 250 WORDS)

Tolbutamide inhibits cAMP-dependent phosphorylation of liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase

The activity of a bifunctional enzyme, liver 6-phosphofructo-2-kinase (PFK-2)/fructose-2,6-bisphosphatase (F-2,6-Pase), which regulates the level of liver fructose-2,6-bisphosphate (F-2,6-P2), the most potent activator of PFK, is modulated by its phosphorylation rate mainly catalyzed by cAMP-dependent protein kinase A (PKA). To elucidate the action mechanism of sulfonylurea on liver F-2,6-P2 production, effects of tolbutamide on PKA-dependent phosphorylation of purified liver PFK-2/F-2,6-Phase protein and on kinase and phosphatase activities of the purified enzyme were examined in vitro. The purified enzyme was phosphorylated in the presence of the catalytic subunit of PKA, and tolbutamide inhibited the enzyme phosphorylation catalyzed by PKA in a dose-dependent manner. By adding the same dosages of tolbutamide used in the phosphorylation experiment, reduced activity of PFK-2 and increased activity of F-2,6-Pase in the presence of PKA were restored to the levels observed in the absence of PKA. On the other hand, carboxytolbutamide, an inactive metabolite of tolbutamide, had little effect on enzyme phosphorylation and activity. Our results indicate that tolbutamide inhibits a phosphorylation of the liver PFK-2/F-2,6-Pase catalyzed by PKA along with an activation of PFK-2 and an inactivation of F-2,6-Pase, leading to liver F-2,6-P2 production.

A polymorphic (CA)n repeat element maps the human glucokinase gene (GCK) to chromosome 7p

A compound imperfect dinucleotide repeat element, [CA]4TTTGT[CT]7[CA]9AA[CA]4CCACATA[CA]3, was found approximately 10 kb 3' to the human glucokinase gene (GCK) from analysis of contiguous genomic DNA obtained from a bacteriophage lambda chromosome walk. Direct human genomic sequencing revealed the source of polymorphism to be variable numbers of CT and CA repeats. Altogether six alleles that range in length from +10 to -15 nucleotides compared to the most common (Z) allele have been identified. Alleles Z, Z + 2, and Z + 4 were present in American Blacks, Pima Indians, and Caucasians, with somewhat varied frequencies among the groups. Two alleles, Z + 10 and Z - 15, appear to be unique to American Blacks, while a Z + 6 allele was observed only in the Caucasian population studied. Observed heterozygosity of the polymorphism in the CEPH reference pedigree collection is 44% and the PIC 0.44. The polymorphism is assayed by PCR amplification and resolution of 32P-end-labeled products (ranging in length from 180 to 205 bp) on denaturing polyacrylamide sequencing gels. Using the PCR assay, the human glucokinase gene was physically localized to chromosome 7 in a panel of rodent/human somatic cell lines. Genetic analysis in CEPH pedigrees placed the dinucleotide repeat element, and thereby the human glucokinase gene, on chromosome 7p between TCRG and a RFLP locus D7S57. The glucokinase dinucleotide repeat genetic marker can now be used to assess the role of the glucokinase gene in diabetes by population association studies. In addition, this repeat marker and others flanking it on chromosome 7 can be used in linkage studies with families segregating the disorder.

Possible mechanism of proteolysis for the extrapancreatic action of tolbutamide

In order to assess the mode of the extrapancreatic action of the sulfonylureas, we evaluated the contribution of a proteolytic mechanism for sulfonylurea action by analyzing the effects of a protease inhibitor on insulin- or tolbutamide-stimulated liver fructose-2,6-bisphosphate (F-2,6-P2) formation using isolated rat hepatocytes. The F-2,6-P2 level in hepatocytes was significantly increased by the addition of insulin or tolbutamide. The stimulatory effect of insulin on the F-2,6-P2 formation was most significant when its level was reduced by the addition of 2 microM of forskolin. Insulin action on F-2,6-P2 formation was inhibited by the addition of a protease inhibitor, p-tosyl-L-arginine methyl ester hydrochloride (TAME). Tolbutamide (2 mM) significantly increased hepatocyte F-2,6-P2 level (P less than 0.01 vs the control level). In the presence of TAME, the stimulatory effect of tolbutamide was also suppressed. The present data suggest that a proteolytic mechanism is important in both insulin and tolbutamide action on the F-2,6-P2 formation, and it may be hypothesized that, like insulin, the chemical mediator of tolbutamide action is formed proteolytically.

Polymorphisms of GLUT2 and GLUT4 genes. Use in evaluation of genetic susceptibility to NIDDM in blacks

The liver/islet (GLUT2) and muscle/adipose tissue (GLUT4) glucose-transporter gene products, membrane proteins that facilitate glucose uptake into cells, are important molecules for normal carbohydrate metabolism. Recent isolation of the genes encoding these proteins provides a means to assess the role of possible defects that might contribute to impaired glucose-stimulated insulin secretion or impaired insulin-mediated glucose uptake, both prominent phenotypic features of non-insulin-dependent diabetes (NIDDM). A GLUT2 cDNA clone was isolated from a human liver cDNA library to search for polymorphisms at this locus in American Blacks. Three highly polymorphic sites were identified, one of which (EcoRI-Hae III) appears to be due to an insertion and/or deletion of 200 base pairs of DNA. Significant linkage disequilibrium between these sites over approximately 30 kilobases of genomic DNA suggested that these polymorphisms could be in linkage disequilibrium with mutations at this locus if they exist. A GLUT4 cDNA clone was also utilized to search for polymorphisms at this locus, but only one previously described polymorphism was observed. GLUT2 and GLUT4 cDNA probes were used to evaluate DNA polymorphisms in genomic DNA from American Blacks with NIDDM. The allelic, genotypic, and haplotypic frequencies of the DNA polymorphisms at these loci did not differ from the frequencies in nondiabetic subjects. Because no associations with NIDDM were found, it appears unlikely that mutations at these loci contribute in a major way to the genetic susceptibility to NIDDM observed in American Blacks.

Polymorphisms of HepG2/erythrocyte glucose-transporter gene. Linkage relationships and implications for genetic analysis of NIDDM

To assess the contribution of the HepG2/erythrocyte glucose-transporter (HepG2 GT) gene to the inherited susceptibility to non-insulin-dependent diabetes mellitus (NIDDM), cDNA and genomic probes were used to search for restriction-endonuclease polymorphisms at this locus. Analysis of DNA from 16 unrelated Black American individuals with 19 enzymes and as many as six different probes, defined four polymorphisms over a 45-kilobase region. Nucleotide diversity (pi = 0.006) was low relative to that at other loci, with an average of 1 in 1700 base pairs different between two chromosomes at this locus. The observed combined heterozygosity for these four sites was 0.69, which indicates that the markers at this locus could be useful for linkage analysis in families. Linkage-disequilibrium values between the four polymorphisms were evaluated by pairwise analysis and extended haplotypes. Calculating pairwise associations by the disequilibrium statistic delta or by another measure of disequilibrium, D' (the maximum likelihood of disequilibrium, which is less dependent on frequency), significant linkage disequilibrium could not be demonstrated. However, the frequencies of the observed extended haplotypes were shown to differ (chi 2 = 9.1, df = 2, P less than 0.025) from predicted frequencies if the sites were in linkage equilibrium in Blacks. The frequencies of these four polymorphisms were determined in Black nondiabetic (n = 44) and NIDDM (n = 63) subjects. Neither the allelic nor genotypic frequencies of the polymorphisms differed between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical experience of chemotherapy with cefmetazole for severe infections accompanying malignant hematological disorders]

We made an attempt to treat with cefmetazole (CMZ) 25 patients who developed severe infectious diseases while suffering with granulocytopenia associated with the treatment of malignant hematological disorders. 1. Determination of bacteriological efficacy While 20 strains were isolated and identified from 15 patients, no significant bacteria were detected in 9 patients. Isolates obtained were: 5 strains of Enterococcus faecalis, 3 strains of Haemophilus influenzae, 2 strains of Staphylococcus epidermidis, 2 strains of Klebsiella oxytoca, 2 strains of Staphylococcus aureus, and 1 strain each of Neisseria sp., Pseudomonas maltophilia, Enterobacter sp., alpha-Streptococcus, beta-Streptococcus and Gram-positive cocci. Causative organisms were eradicated or markedly in 7 of the 15 patients from whom bacteria were isolated. Clinical findings, including fever, revealed that none of the patients, in whom bacteriological efficacy was determined to be poor, exhibited sufficient clinical response. E. faecalis was isolated from 4 of 6 patients bacteriologically determined to have no response. 2. As for 23 patients, who were found to be evaluable among the 25 patients, 8 (34.8%), 4 (17.4%), 4 (17.4%), and 7 (30.4%) demonstrated excellent, good, fair and poor responses, respectively, showing a 69.6% efficacy rate which indicates a sum of percentages of patients with excellent, good and fair responses. 3. While an efficacy rate of 100% was obtained for 3 patients with number of peripheral neutrophils less than 500/mm3 before the beginning of CMZ administration, only an efficacy rate of 66.7% was obtained for 15 patients with neutrophils more than 500/mm3.(ABSTRACT TRUNCATED AT 250 WORDS)

A clinical evaluation of transcatheter arterial embolization on hepatocellular carcinoma

TAE was performed in 49 cases of HCC for clinical assessment of the usefulness. This procedure was aimed to subside intraperitoneal hemorrhage in 8 cases among them and to provide a possible antitumor effect in the remaining 41 cases. The prognosis in the 8 cases of intraperitoneal hemorrhage was 54.9 +/- 41.1 days including one case survived as long as 116 days. The prognosis in the remaining 41 cases was 12.6 +/- 8.3 months in group A, 7.8 +/- 6.1 months in group B and 1.6 +/- 1.3 months in group C according to Child's classification, while it was 2.8 +/- 2.5 months in 1st branch occluded, 9.4 +/- 6.1 months in IInd branch occluded and 19.2 +/- 6.7 months in IIIrd branch occluded group according to the portal vein occlusion due to tumor thrombi suggesting that a more prolonged survival was attained with more favorable degree of Child's classification and less affected portal embolization. The cumulative survival time (by Kaplan-Meier's methods) was 6 months in 89% of the cases examined, 1 year in 59%, 2 years in 34% and 3 years or more in 11%, indicating significantly higher survival as compared to our TAI group. Angiographic re-opening of tumor vessel within 3 months was observed in 46.7%. TAE on HCC was useful both for the purpose of antitumor effect and of hemostasis. The degree of Child's classification and severity of portal occlusion at the initial examination may closely relate to the prognosis. Thus, angiography should be repeated within 3 months following the first TAE at least.

[Relationship between clinical efficiency of cefoperazone and the value of area under the time concentration curve in infectious diseases]

Clinical efficiency and side effects of cefoperazone (CPZ) against 40 infectious diseases in the field of internal medicine were studied. In addition, relationship between clinical efficiency and the value of area under the time concentration curve (AUC) was evaluated. It was possible to evaluate clinical responses in 36 cases of 40 infections; Responses were excellent in 15, good in 16, fair in 3 and poor in 2. An overall efficacy rate was 86.1%. A high dose of CPZ (2 g X 2/day) produced a higher efficacy rate than a low dose of the drug (1 g X 2/day) [95.8% (23/24 cases) vs. 66.7% (8/12 cases)] but the difference was not statistically significant. It was possible to evaluate bacteriological efficacy in 32 cases. Bacteria were eradicated in 29 (90.6%) and decreased in 3. The value of AUC in the high dose group was significantly higher than that in the low dose group. Values of AUC in cases of excellent or good clinical responses tended to be higher than values in cases of fair or poor responses. Side effects were noted in 4 cases, but they were not serious and improvements were observed without withdrawal of the drug except 1 case.

Effect of tolbutamide on fructose-6-phosphate,2-kinase and fructose-2,6-bisphosphatase in rat liver

The effects of tolbutamide on the activities of fructose-6-phosphate,2-kinase and fructose-2,6-bisphosphatase were examined using rat hepatocytes. Tolbutamide stimulated fructose-6-phosphate,2-kinase activity and inhibited fructose-2,6-bisphosphatase activity, resulting in an increase of fructose-2,6-bisphosphate level. Changes in the activities of the enzyme by tolbutamide were due to variation in the Km value, but not dependent on alteration of Vmax. Glucagon inhibition of fructose-2,6-bisphosphate formation resulting from an inactivation of fructose-6-phosphate,2-kinase and an activation of fructose-2,6-bisphosphatase was released by tolbutamide. Tolbutamide stimulation of fructose-2,6-bisphosphate formation through regulation of fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase may produce enhancement of glycolysis and inhibition of gluconeogenesis in the liver.

Tolbutamide stimulates fructose-2, 6-bisphosphate formation in perfused rat liver

Effect of tolbutamide on liver fructose-2,6-bisphosphate (F-2,6-P2) was examined in isolated perfused rat liver in situ with a flow-through method. Tolbutamide (1 mM) gradually increased liver F-2,6-P2 level from 7.4 +/- 1.6 to 21.2 +/- 1.6 pmol/mg wet wt for 20 min perfusion. The increase of liver F-2,6-P2 induced by tolbutamide was dose dependent and was significantly observed at 10 min perfusion. The maximum plateau level of F-2,6-P2 induced by 16.7 mM glucose was further increased with 1 mM tolbutamide. Glucagon (10(-11) M) decreased the elevated level induced by 16.7 mM glucose, but this effect was completely inhibited with 2 mM tolbutamide. Cyclic AMP level of the liver throughout the perfusion with tolbutamide did not change. Carboxytolbutamide or gliclazide perfusion did not change significantly the liver F-2,6-P2 level; however, the results suggest that tolbutamide may increase the liver F-2,6-P2 level by affecting the phosphorylation state of fructose-6-phosphate, 2-kinase/fructose-2,6-bisphosphatase through cyclic AMP-dependent protein kinase, resulting in the stimulation of glycolysis and the inhibition of gluconeogenesis in the liver. Thus, the extrapancreatic action and the mechanism of action of different sulfonylureas may differ.