High degree of myeloid differentiation and granulocytosis is associated with t(8;21) smoldering leukemia

The t(8;21) is a frequent chromosome abnormality in acute myeloid leukemia (AML), particularly associated with M2 of the French-American-British (FAB) classification, but also found in a few patients with myelodysplastic syndrome (MDS). The two genes involved in the t(8;21) have been recently isolated and the cDNA of the AML1/ETO fusion gene identified. We have investigated a series of AML and MDS patients by a reverse transcriptase-polymerase chain reaction (RT-PCR) and analyzed the clinical and laboratory features of leukemia with t(8;21). The t(8;21) was only found in a subset of M2, which had the clinical and hematological features distinct from those M2 without t(8;21). M2 with t(8;21) was associated with a significantly higher myeloid differentiation and with a good response to chemotherapy. Moreover, among the patients with refractory anemia with excess of blasts in transformation (RAEB-T) the t(8;21) was also significantly associated with a higher myeloid differentiation and a good response to chemotherapy. M2 patients with t(8;21) could be distinguished on a number of hematological parameters, eg white blood cell count and percentage of bone marrow myeloblasts and promyelocytes, from RAEB-T carrying the t(8;21). Based on these findings we suggest that leukemia patients carrying t(8;21) can be grouped into two types; overt acute myeloid leukemia (M2) and smoldering or slowly evolving myeloid leukemia.

Oxidative modification of low density lipoprotein by diesel exhaust particles

Oxidized low density lipoprotein (LDL) has a variety of hazardous influences on biological systems. Oxidative modification of LDL by diesel exhaust particles (DEP) was studied in vitro to assess its in vivo health effects. DEP suspensions (1, 10 and 100 micrograms/ml) were incubated for 1 h with LDL (1 mg protein/ml) at 37 degrees C. Conjugated diene formation and negative charges in LDL were increased by DEP-treatment in a dose-dependent manner. When native LDL and DEP-treated LDL (DEP-LDL) were incubated for 18 h with macrophage, J774A.1 cell at 37 degrees C, significantly more DEP-LDL was taken up into cells than native LDL. Accumulation of cholesterol ester in cells incubated with DEP-LDL was 4 to 8 times higher than that with native LDL while there was no significant difference between them in free cholesterol content. Incubation (18 h) of J774A.1 with DEP-LDL caused an increase in leakage of lactate dehydrogenase from cells in a DEP-concentration dependent manner, but the incubation with native LDL or DEP per se did not increase the leakage except at the highest concentration of DEP. These results suggest that DEP oxidatively modified LDL giving it cytotoxic, inflammatory and atherogenic properties characteristic of so-called oxidized LDL; these initial modifications of LDL may be one of the underlying mechanisms for diseases associated with DEP.

Scalp hair loss caused by octreotide in a patient with acromegaly: a case report

We used octreotide to treat a woman with acromegaly and observed pituitary adenoma shrinkage after 5 months. Diffuse scalp hair loss occurred after 5 months, resulting in the discontinuation of treatment. After the cessation of octreotide, the hair loss stopped and hair growth resumed. Since bromocriptine did not effectively decrease the GH level of the patient, we decided to perform transsphenoidal surgery. After resection of the pituitary adenoma, her GH and IGF-1 levels were normalized. Although octreotide-induced scalp hair loss has not been well recognized, we should pay more attention to this side effect.

Potent ectopic bone-inducing activity of bone morphogenetic protein-4/7 heterodimer

We have purified and characterized recombinant Xenopus bone morphogenetic proteins (xBMPs): homodimers of xBMP-4, 7 and heterodimers (xBMP-4/7) produced by a baculovirus expression system. Highly purified xBMPs had homogeneous NH2-termini predicted from a consensus motif, Arg-X-X-Arg, while they possessed diverse sugar chains. Implantation of xBMPs together with pure collagen carrier in rats induced new bone formation in a dose-dependent manner. The xBMP-4/7 heterodimer showed the strongest activity, with an effective dose of 1-30 micrograms, while more than 10 micrograms of xBMP-4 or 7 homodimer was required for a significant effect. Histological examination revealed that xBMP-4/7 implants showed intramembranous ossification without chondrogenesis. In primary cultures of rat bone marrow stromal cells, xBMP-4/7 induced alkaline phosphatase 3-fold more strongly than xBMP-7 and 20-fold more than xBMP-4. These results suggest that the heterodimeric form of BMP would generate the strongest signal triggering osteogenic differentiation of osteoprogenitor cells in adult tissues.

[Intracranial tuberculoma with spontaneous recovery]

A 57-year-old man was admitted because of headache, nausea, and fever up (38 degrees C). He showed nuchal rigidity slightly. CSF analysis showed 833 white blood cells (WBC) (80% monocyte), protein value of 68 mg/dl, glucose level of 36 mg/dl and ADA level of 11.8 IU/l. Brain pre-contrast CT indicated high density area in right parietal lobe, and it showed slightly homogeneously enhancement with contrast medium. MRI on T2 WI demonstrated hypointense lesion with bright central core in right parietal lobe. The lesion showed isointense on T1WI, and indicated homogeneous enhancement with Gd-DTPA. He was sent to our hospital after one week. With only antibiotics the symptoms were relieved and the CSF findings improved during the previous hospital. However, Mycobacterium tuberculosis (M. tuberculosis) DNA was detected in CSF by PCR amplification, and he recovered completely with anti-tuberculous treatment. This case was interesting to reveal atypical features of spontaneous recovery. Since Shankar's study using polymerase chain reaction (PCR) for detection of M. tuberculosis in cerebrospinal fluid (CSF), the PCR assay have been recognized to be a rapid method for diagnosis of tuberculous meningitis (TBM). But there are problems of PCR sensitivity when dealing with CSF samples containing small amount of M. tuberculosis DNA. Comparing direct PCR with nested PCR, we studied on the evaluation of PCR for diagnosis of TBM. In this study the nested PCR was positive in all CSF specimens from 4 patients with TBM, but we could not detect M. tuberculosis DNA by only the direct PCR. Nested PCR amplification improved the sensitivity and specificity.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-genotoxic mechanisms of carcinogenesis: studies of cell transformation and gap junctional intercellular communication

It is widely accepted that a series of genetic changes accumulate during carcinogenesis. In addition, it is likely that various non-genotoxic mechanisms also operate at different stages of carcinogenesis. It is even possible that non-genotoxic mechanisms indirectly generate genetic changes, e.g., through induction of cell proliferation, active oxygen species or cytosine methylation. This may partially explain why many carcinogens are devoid of activity when tested in the usual genetic toxicology assays. In vitro cell transformation mimics certain stages of in vivo carcinogenesis. It has therefore been proposed that both genotoxic and non-genotoxic aspects of carcinogenesis can be studied in cell transformation systems, with tumor formation by transformed cells in syngenic animals or nude mice as the endpoint. Many genotoxic as well as non-genotoxic carcinogens induce transformation of Syrian hamster embryo, murine Balb/c 3T3 and murine C3H10T1/2 cells; interaction of genotoxic and non-genotoxic mechanisms can be clearly seen in 2-stage cell transformation studies in which a genotoxic initiating agent and a non-genotoxic promoting agent act synergistically to induce transformation of rodent cells. Aberrant control of gap junctional intercellular communication (GJIC) in cell transformation and carcinogenesis is well documented. Possible genotoxic as well as non-genotoxic mechanisms involved in abnormal gap junction communication control in multistage carcinogenesis are discussed.

Inhibition of rat liver gap junction intercellular communication by tumor-promoting agents in vivo. Association with aberrant localization of connexin proteins

BACKGROUND

Gap junctional intercellular communication is believed to play an important role in the maintenance of tissue homeostasis, and disruption of it has been proposed to be involved in carcinogenesis. A number of tumor-promoting agents have been shown to inhibit capacity for intercellular communication in cell culture studies. Recently, we developed a simple dye-transfer technique to evaluate cell-coupling function in fresh liver slices, and we used it to show that inhibition of intercellular communication is associated with rat liver tumor progression. Using this method with analysis of gap junction protein connexin expression, we have examined whether and how different liver-specific tumor-promoting agents inhibit dye-coupling in rat liver in vivo.

EXPERIMENTAL DESIGN

Groups of Fischer 344 rats received repeated chronic treatment of phenobarbital (PB), polychlorinated biphenyls (PCB), dichlorodiphenyltrichloroethane (DDT), and clofibrate (CF) for 5 weeks. After 1, 2, and 5 weeks of treatment, intercellular communication via gap junctions was evaluated by the dye-transfer assay in liver slices taken immediately after killing the rats. In parallel, the expression of connexins (cx) 32, 26, and 43 (gap junction proteins expressed in the liver) was studied at the mRNA and protein levels.

RESULTS

All four tumor-promoting agents decreased dye-coupling in rat liver. This decrease was associated with a reduced number of gap junctions and aberrant localization of some amount of cx 32 proteins in hepatocytes; cx 32 often was observed in the cytoplasm of hepatocytes instead of at gap junctions in the plasma membrane. Western blot analysis showed only slight changes in the level of cx 32 proteins. Although cx 26 proteins at gap junctions were usually decreased by tumor promoters in rat liver, local induction of cx 26 protein expression in centrolobular groups of hepatocytes after PCB and DDT treatment was observed. The expression of cx 43 was induced in hepatocytes after PCB, DDT, and CF exposure, but this protein was also localized intracytoplasmically, suggesting no functional role. All four tested tumor-promoting agents also increased cell proliferation, as revealed by staining with an anti-Ki 67 antibody.

CONCLUSION

The results demonstrate that different types of liver tumor-promoting agents inhibit dye-coupling in rat liver in vivo. This inhibition may be due to aberrant localization of the major liver gap junction protein cx 32, rather than its transcriptional or translational disregulation.

Decreased expression of the GLUT4 glucose transporter protein in adipose tissue during pregnancy

Insulin resistance involves impaired activities of the glucose transport system in insulin target tissues. We therefore investigated the GLUT4 glucose transporter protein in adipose tissues from the pregnant women with normal glucose tolerance and from women with gestational diabetes mellitus, and compared these to nonpregnant women. Three groups of women were studied: nonpregnant women with normal glucose tolerance (N = 6), pregnant women with normal glucose tolerance (N = 6, gestational week 38.0 +/- 0.3), and pregnant women with gestational diabetes mellitus (N = 3, gestational week 38.6 +/- 0.3). The abdominal subcutaneous adipose tissues obtained from each group were subjected to analysis of the GLUT4 glucose transporter protein. The presence of the GLUT4 glucose transporter protein in the three groups was quantitatively determined by Western blot analysis of detergent-soluble adipose tissue extracts using anti-GLUT4 antibody. GLUT4 glucose transporter protein concentration in the adipose tissue of pregnant women were significantly lower than that in nonpregnant women, and this difference was more profound in women with gestational diabetes mellitus. We demonstrated that the content of GLUT4 protein was decreased in adipose tissue from normal pregnancy compared to nonpregnant women.

Identification of two transcripts of AML1/ETO-fused gene in t(8;21) leukemic cells and expression of wild-type ETO gene in hematopoietic cells

The t(8;21) is a common chromosomal abnormality, preferentially associated with acute leukemia showing features of myeloid differentiation. Recently, two genes--AML1, which has a unique runt domain, and ETO (MTG8)--have been isolated from the chromosomal breakpoint. In this study, we isolated and identified two fused transcripts from a leukemic cell line carrying t(8;21). AML1 and ETO were fused at the same position in these transcripts. One of the transcripts codes a unique domain, including two zinc finger domains and three proline- and one leucine-rich region. The other transcript codes only for one proline- and leucine-rich region but lacks zinc finger domains. We demonstrated by polymerase chain reaction (PCR) analysis that 1) these two transcripts are consistently expressed in leukemic cells with t(8;21) obtained from patients and 2) expression of AML1 was not restricted to the particular stage of hematopoietic differentiation but was present in all hematopoietic cells investigated. We also provide evidence that two wild types of ETO transcripts containing the region of the ETO gene in fused transcripts are expressed in hematopoietic cells from different lineages. The widespread expression of AML1 and ETO in hematopoietic cells suggests a fundamental role of these proteins in hematopoiesis. Furthermore, the differences in the carboxy termini of ETO may modulate the activity of fused proteins resulting from the chromosomal translocation t(8;21).

Microsatellite alterations in human and rat esophageal tumors at selective loci

(CA)n simple repeats in DNA were examined at 17 loci in 18 human squamous cell carcinomas of the esophagus and compared with those in normal esophageal tissue from the same patients. Six loci were examined in 32 esophageal papillomas that had been induced by N-nitrosomethylbenzylamine in BD VI rats. Length-altered CA repeats were found in two human tumors and four rat papillomas. Loss of heterozygosity was observed in three human tumors; two rat papillomas had lost microsatellite bands that are common in inbred BD VI rats. Both (CA)n microsatellite length alteration and loss of heterozygosity were clustered at certain loci in the human tumor samples and in the chemically induced rat esophageal tumors. Our findings indicate that genomic instability that results in alteration of repeated sequences not only occurs in human tumors but may also be a consequence of chemical carcinogenesis in rodents.

Abundant expression of GLUT1 and GLUT3 in rat embryo during the early organogenesis period

The developmental change of both GLUT1 and GLUT3 protein in rat embryonal and fetal brain was examined using Western blot analysis and immunohistochemistry. The brains were collected from fetuses (gestational days 10 to 20), newborn, and adult rats. On day 10, the levels of GLUT1 and GLUT3 expressions were twofold higher than those of adult levels, but thereafter decreased rapidly as the gestation progressed. The tissue distribution of GLUT1 and GLUT3 in embryo was apparently distinct. On day 10, GLUT1 was expressed in the neural tube, gut, heart and optic vesicle, while GLUT3 was expressed in the surface ectoderm and gut. Thus, high affinity glucose transporters may be required in the early organogenesis period because their energy requirement is completely dependent upon anaerobic glycolysis. GLUT3 may facilitate glucose transfer from amniotic fluid to the embryo and GLUT1 may supply glucose for use as an embryonal fuel.

p53 gene mutation and loss of heterozygosity are associated with increased risk of disease progression in adult T cell leukemia

Although the prototype of adult T cell leukemia (ATL) is an aggressive T cell neoplasm, ATL manifests four major clinical subtypes, acute, lymphoma, chronic, and smoldering. We studied the relationship between p53 gene alteration and clinical features in 34 patients with ATL, 14 acute type, 15 chronic type, and five crisis type transformed from chronic type. Using a polymerase chain reaction/single strand conformation polymorphism (PCR/SSCP) assay, followed by nucleotide sequencing, we detected mutations of the p53 gene in six of the 14 acute type patients, two of the five crisis type, and one of the 15 chronic type patients. Gene dosage studies, using PCR amplification and Southern blotting, showed loss of heterozygosity (LOH) of the p53 gene in four of the 14 acute type patients, two of the five crisis type, and one of 14 chronic type patients examined. These observations indicated that the frequency of p53 gene alterations in the acute and crisis types of ATL was markedly higher than that in chronic type, suggesting that p53 gene alteration plays a role in the disease progression of ATL.

Hypothyroidism preceding hyperthyroidism in a patient with continuously positive thyroid stimulating antibody

A 62-year-old woman was initially hypothyroid and then developed hyperthyroidism with continuously positive thyroid-stimulating antibody (TSAb). When she visited our hospital with the complaint of the feel of skipping beats, her serum free T4 level was initially low and thyrotropin (TSH) level was slightly elevated. One month after starting the supplement therapy with l-T4, she developed hyperthyroidism with increased 123I-thyroid uptake. TSH-binding inhibitor immunoglobulin (TBII) was slightly elevated only during the hypothyroid stage. Throughout the whole course, TSAb was continuously positive, while thyroid stimulation-blocking antibody (TSBAb) was not detectable. Primary hypothyroidism with TSAb may suggest the possibility of subsequent development of hyperthyroidism.

Thyrotropin binding specificity for the thyrotropin receptor

Recently, highly purified bovine thyrotropin (bTSH) of pituitary origin, as well as recombinant human (h) TSH free of lutropin (LH) contamination, has been reported to activate the LH/choriogonadotropin receptor (LH/CGR). These data challenge the concept of TSH specificity for its own receptor. We, therefore, re-evaluated these data using, as targets, the recombinant hTSH and rat LH/CGRs stably expressed in Chinese hamster ovary (CHO) cells. Partially purified bTSH (2 IU/mg protein) and, to a lesser degree, highly purified bTSH (30 IU/mg protein) increased intracellular cAMP levels in CHO-LH/CGR cells (an EC50 of 0.2 and > 20 mIU/ml, respectively). In contrast, recombinant hTSH (up to 1 IU/ml) did not. All three TSH preparations increased cAMP levels to the same extent in CHO-TSHR cells (an EC50 of 0.3 mIU/ml). Furthermore, we observed only nonspecific, low affinity TSH binding for CHO-LH/CGR cells and also for CHO cells transfected with the expression vector alone (a Kd of 100 nM), although both high and low affinity TSH binding was demonstrated in CHOT-SHR cells (a Kd of 0.3 and 100 nM, respectively). These data indicate that even highly purified bTSH of pituitary origin contains significant amounts of LH, and that TSH itself does not appear to activate the LH/CGR.

Purification and characterization of the serotype-specific polysaccharide antigen of Trichosporon cutaneum serotype II: a disease-related antigen of Japanese summer-type hypersensitivity pneumonitis

Summer-type hypersensitivity pneumonitis (SHP) is a unique type of hypersensitivity pneumonitis and the most prevalent in Japan. Our previous study clarified that the causative agent of the disease is Trichosporon cutaneum, and that the patients with SHP have high titres of antibodies against the serotype-specific antigen of polysaccharide nature which exist in the high molecular weight fraction of the culture supernatant of the yeast. In this study, we purified the serotype-specific antigen of serotype II T. cutaneum by gel filtration and affinity chromatography using a monoclonal antibody, D-8, specific for a high molecular weight antigen of serotype II T. cutaneum, and elucidated the structure of the antigen. This affinity-purified antigen was shown to be an essentially acidic polysaccharide comprising mannose, xylose, and glucuronic acid (6:44:4.7). Chemical analysis showed that this polysaccharide antigen contains a (1-3)-linked mannan backbone attached with short side chains of (1-4)-linked mannose and a small proportion of (1-2)-linked xylose residues by substituting the 2- or 4-positions of the (1-3)-linked mannose residues of the main chain. Approximately one-fifth of the side chains were terminated with glucuronic acid residues. The antigenic epitope of the serotype-specific antigen was shown to involve the terminal glucoronic acid residues as revealed by immunodiffusion test and sandwich enzyme-linked immunosorbent assay using monoclonal antibody D-8.

Function of the sphincter of Oddi in patients with juxtapapillary duodenal diverticula: evaluation by intraoperative biliary manometry under a duodenal pressure load

The purpose of this study was to elucidate the function of the sphincter of Oddi (SO) in patients with juxtapapillary duodenal diverticula (JDDs). The SO function was evaluated by intraoperative biliary manometry in three groups of patients. Group 1 consisted of nine patients with JDDs and a dilated common bile duct (CBD) (diameter > 10 mm). Group 2 consisted of six patients with JDDs and a normal-sized CBD (diameter < 10 mm). Group 3 consisted of 26 patients without JDDs and with normal-sized CBDs. In the absence of a duodenal pressure load, the patients in group 1 demonstrated a lower baseline SO pressure and lower resistance of the biliary outflow than patients in group 3. They also demonstrated a lower baseline SO pressure and shorter decay time (which represented terminal biliary ductal resistance) than patients in group 2. In the presence of a duodenal pressure load of 300 mm H2O, the patients in group 1 demonstrated a lower incidence of phasic SO contractions, a higher baseline SO pressure, and a higher resistance of the biliary outflow than group 2 and group 3 patients. The decay time in group 1 and group 2 patients was higher than that of group 3 patients. Based on these findings, we conclude that the SO function in patients with JDDs is impaired owing in part to long-standing compression of the terminal biliary ductal system by a distended JDD associated with a rise in intraduodenal pressure in daily life.

Negative growth control of HeLa cells by connexin genes: connexin species specificity

In order to examine whether different connexin gene species exert different degrees of tumor-suppressing activity, we characterized growth characteristics of a gap junction-deficient human cancer cell line, HeLa cells, before and after transfection with cDNA for three different connexins, connexin (cx) 26, cx 40, and cx 43. All transfected cell lines (3 clones transfected with the cx 26 gene, 2 clones with cx 40, and 1 with cx 43) showed establishment of gap junctional intercellular communication (GJIC). Two of the cx 26-transfected clones showed significantly slower growth compared with the parental HeLa cells. When transfectants were grown in soft agar, the three cx 26-transfected clones grew much less than the other transfectants and parent HeLa cells. When injected into nude mice, the two cx 26 clones which exhibited the highest amount of cx 26 transcript induced almost no tumors, whereas other transfectants, including the cx 26 clone which exhibited the lowest amount of cx 26 transcript, were tumorigenic. Among transfectants of various connexin genes, there was no good inverse correlation between their GJIC and tumorigenicity. GJIC levels were significantly higher in tumors induced in nude mice by clone cx 26 A and E transfectants. These results suggest that all of the connexin genes examined could induce recovery of GJIC of HeLa cells, but only the cx 26 gene exerts strong negative growth control on HeLa cells; thus, this connexin gene may have different functions from other connexin genes.

Lack of the expression of EBNA-2 and LMP-1 in T-cell neoplasms possessing Epstein-Barr virus

We investigated 34 cases of T-cell neoplasm [15 cases of T-cell granular lymphocytic leukemia (T-GLL), 10 cases of T-cell non-Hodgkin's lymphoma (T-NHL), six cases of T-cell chronic lymphocytic leukemia (T-CLL), and three cases of cutaneous T-cell lymphoma] to study their association with Epstein-Barr virus (EBV). In 4 (three T-NHL and one T-GLL) of 34 cases, EBV genome was detected in a single episomal form, while polyclonal EBV-DNA was detected in one (T-NHL) of the remaining cases. All three cases of T-NHL having monoclonal EBV episome showed histologically diffuse large-cell lymphoma and developed leukemic conversion. Phenotypic analysis showed that two of these four cases were CD4+, CD8-, and the remaining two cases were CD4-, CD8+. The cells from all four cases were confirmed to be in T-cell lineage by detecting the rearrangement of T-cell receptor (TCR) beta or gamma chain gene. By reverse transcription-polymerase chain reaction (RT-PCR), EBNA-1 was detected at low levels, and neither EBNA-2 nor LMP-1 were found in any of the three cases examined. Lack of the expression of EBNA-2 and LMP-1 was also confirmed by immunocytochemical staining. The cells of these four cases did not show rearrangement or overexpression of c-myc and bcl-2 genes by Southern and Northern blots, and the mutation of p53 gene was detected in only one patient. These results suggest that other latent gene products of EBV or other cellular oncogenes are involved in the development of Japanese T-cell neoplasm after EBV infection.

Transvaginal ultrasonographic morphology in polycystic ovarian syndrome

To assess the morphological findings based on transvaginal ultrasound, the ovarian volume and the number and size of small follicles were studied in 47 patients with polycystic ovarian syndrome (PCOS) diagnosed clinically. Thirty normal volunteers served as controls. The mean ovarian volume (10.3 ml) and number of follicles (10.6) in patients with PCOS were significantly higher than those of controls. An ovarian volume > 6.2 ml and follicles > 10 with a diameter of 2-8 mm were the most prominent features in the ovaries of patients with PCOS and 94% of 47 patients with PCOS had at least one of these ultrasonic findings. However, marked asymmetry of the two ovaries was seen in about 50% of patients with PCOS and a considerable overlap existed between controls and patients with PCOS in the ovarian volume and in the number of follicles. Three (6%) patients with normal ovarian volume and normal number of follicles were observed. Therefore, it is difficult to clearly distinguish a patient with PCOS from a normal woman only by transvaginal ultrasonic criteria using the ovarian volume and/or the number of follicles, although these criteria could be clinically useful for the screening of PCOS.

Studies on the tumor-promoting activity of additives in biomaterials: inhibition of metabolic cooperation by phenolic antioxidants involved in rubber materials

For the detection of tumor-promoting activities of phenolic antioxidants, the inhibitory activities on the intercellular gap-junctional communication were investigated using the V79 metabolic cooperation (MC) assay. Among eight antioxidants, 4,4'-butylidene-bis(3-methyl-6-tert-butyl-phenol), 2,2'-methylene-bis(4-methyl-6-tert-butylphenol) (MBMBP), and styrenated phenol (SP) showed stronger inhibitory activities than lithocholic acid, which is known to be a tumor promotor. However, 4,4'-thio-bis(3-methyl-6-tert-butylphenol), Irganox 1010, and 1330 did not inhibit at any concentrations. When the single-electron oxidation potentials were compared among antioxidants, the electrochemical ease estimated with the first oxidation potential was correlated with the cytotoxic potentials (r = 0.88), but not with the inhibitory activities in an MC assay. The tumor-promoting activity of MBMBP was also investigated using an in vitro, two-stage Balb/c 3T3 transformation assay. MBMBP did not show initiating activity, but significant promoting activity at concentrations of both 1 and 2.5 micrograms/ml were noted. These concentrations were close to the lowest effective inhibitory concentration (1.3 micrograms/ml) of MBMBP in an MC assay. In conclusion, there is a possibility that the phenolic antioxidants that show inhibitory activities in an MC assay contribute to the enhancement of tumor incidence induced by biomaterials.

Molecular analysis of insulin receptor gene in Werner's syndrome

Werner's syndrome is characterized by premature aging and frequent impaired glucose tolerance or overt diabetes. Insulin resistance may play an important role and may be caused by a post-receptor defect or dysfunctional insulin receptor. The present study was undertaken to investigate the insulin receptor gene mutation in Werner's syndrome. The genomic DNAs were obtained from four patients with Werner's syndrome. Exons 2-22 of the insulin receptor gene except exon 1 were amplified from genomic DNA by the polymerase chain reaction and screened for nucleotide variation by examining for single-stranded conformational polymorphisms. There were no nucleotide variations in exons 2, 4-->7, 9 and 12-->22. Variants were thus found in exons 3, 8, 10 and 11 and each were sequenced. The variant in exon 8 was due to a silent polymorphism (GAT-->GAC/T, Asp519) and other variants in exons 3, 10 and 11 were caused by nucleotide substitutions in introns. These results suggest that the patients with Werner's syndrome express normal insulin receptors and that the primary genetic lesion for insulin resistance is not in the insulin receptor gene. Insulin resistance in Werner's syndrome is thus likely by a post-receptor defect.

Insulin response after treatment depends on fasting plasma glucose level in NIDDM

We investigated the relationship between the improvement in insulin secretion and glycemic control in non-insulin-dependent diabetes mellitus (NIDDM). Fifty-two patients were classified into three groups according to their pretreatment fasting plasma glucose (FPG) level: Group A, FPG < 7.8 mM, n = 20; Group B, 7.8 mM < or = FPG < 11.1 mM, n = 17; and Group C, 11.1 mM < or = FPG, n = 15. A 75-g oral glucose tolerance test (OGTT) and a glucagon loading test were performed to evaluate insulin secretion before and after treatment. Plasma glucose levels during a 75-g OGTT were decreased significantly after treatment in all groups (P < 0.01). In Group A, there was no significant change in insulin secretion before and after treatment (1466 +/- 213 pM to 1565 +/- 191 pM, P = 0.35). In contrast, in Groups B and C, insulin secretion was poor and suppressed initially, but increased significantly when good glycemic control was obtained after treatment (respectively, 587 +/- 70 pM to 863 +/- 79 pM, P < 0.01, and 621 +/- 94 pM to 1236 +/- 232 pM, P < 0.01). The degree of improvement in insulin secretion in 75-g OGTT correlated positively with the degree of improvement in FPG level after treatment (r = 0.5, P < 0.001). However, the C-peptide response to glucagon did not change before and after treatment. In conclusion, impaired insulin secretion recovered by the good glycemic control in NIDDM with FPG levels above 7.8 mM. Therefore, strict glycemic control (FPG below 7.8 mM) seems important for maintaining good insulin secretion.

Leishmania major-like parasite, a pathogenic agent of cutaneous leishmaniasis in Paraguay

Leishmania parasites isolated from two patients with cutaneous leishmaniasis from geographically different localities in Paraguay have been characterized by enzyme electrophoresis (zymodeme) and digestion profiles of kinetoplast DNA with restriction enzymes (schizodeme). Both Paraguayan isolates showed identical zymodeme profiles to each other using 14 enzymes (glutamic pyruvate transaminase, glutamic oxaloacetic transaminase, enolase, fumarate hydratase, glucose phosphate isomerase, glucose-6-phosphate dehydrogenase, malate dehydrogenase, malic enzyme, mannose phosphate isomerase, nucleoside phosphorylase, peptidase-D, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and pyruvate kinase). Although two Paraguayan isolates showed different zymodeme profiles from those of six Leishmania reference strains of Old and New World Leishmania species, they showed identical zymodeme profiles to those of an L. major-like parasite from Ecuador. These observations were confirmed by schizodeme analysis using three restriction endonucleases (Msp I, Hae III, and Taq I). These results indicate that Leishmania parasites isolated in Paraguay are identified as an L. major-like parasite, and it is necessary to consider the existence of L. major-like parasites when classifying Leishmania isolates from the New World.

CD4+ CD8+ granular lymphocytic leukemia arising in a patient with acute myeloblastic leukemia

A 59-year-old woman who had an 8-year history of acute myeloblastic leukemia (AML) developed granular lymphocytic leukemia (GLL). She had a small number of granular lymphocytes (GL) in her bone marrow (BM) at the onset of AML. The GL increased during complete remission (CR) of AML, but not at the relapse. During the third CR state of AML, GL increased to 4.0 x 10(9)/l in the peripheral blood (PB). The GL were T-cell receptor (TCR) alpha beta+ T cells and expressed both CD4 and CD8 antigens. Rearrangements of TCR beta and gamma chain genes were detected in the peripheral blood mononuclear cells (PBMNC), confirming that this patient had GLL. The PBMNC from the patient responded weakly to PHA or ConA, yet they responded to her own bone marrow mononuclear cells (BMMNC) or CD4-depleted BMMNC that contained AML cells stronger than her own PBMNC or normal PBMNC. These observations suggest that monoclonal proliferation of GL developed after the reactive proliferation of GL in response to AML cells.