CMDME (curved mesh diagram of mandibular excursion) method for visualization and diagnosis of mandibular movement

The CMDME (curved mesh diagram of mandibular excursion) method was developed for easy visualization and diagnosis of mandibular movement. This method uses measured mandibular movement to produce a diagram of the range, shape, and inclination of mandibular excursion in three dimensions using any arbitrary landmark of the mandible. First, the mandibular movement of a subject was measured by an opto-electronic movement analysis system capable of measuring mandibular movement with six degrees-of-freedom at a sampling frequency of 100 Hz. For the measurement, the subject was initially instructed to perform four repetitions of mandibular excursion at will, with tooth contact, each lasting 30 s. A total of 12 000 positions of the mandible were thus obtained. Secondly, an attempt was made to match these positions to intersection points (0.1 mm apart) of a CMDME (i.e. mesh) for arbitrary mandibular landmarks with intercuspal position at the origin. The CMDME method can visualize mandibular excursion, and can be used to compare several landmarks, different subjects, or different times. This makes this method an effective diagnostic tool for mandibular movement.

Increased hepatic glucose production and decreased hepatic glucose uptake at the prediabetic phase in the Otsuka Long-Evans Tokushima fatty rat model

To investigate the time course of the hepatic glucose metabolism in non-insulin-dependent diabetes (NIDDM), we measured hepatic glucose production (HGP) and first-pass uptake of portal glucose infusion by the liver (HGU) using dual-tracer methods in a NIDDM model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, and in normal controls, Long-Evans Tokushima Otsuka (LETO) rats, at 8, 14, and 28 weeks of age (n = 5, respectively). The fasting plasma glucose level in OLETF rats was significantly higher than in LETO rats at 28 weeks of age (8.9 +/- 1.7 v 6.3 +/- 0.4 mmol/L, P < .01), while there was no significant difference at 8 and 14 weeks. Hyperinsulinemia in OLETF rats appeared at > or = 8 weeks of age. Basal HGP was significantly higher in OLETF than in LETO rats at 8 and 28 weeks (8 weeks, 12.7 +/- 1.7 v 9.4 +/- 1.8 mg x kg(-1) x min(-1), P < .05; 28 weeks, 10.9 +/- 1.6 v 7.1 +/- 1.3 mg x kg(-1) x min(-1), P < .01). At 14 weeks, basal HGP was not significantly different between OLETF and LETO rats. However, at all study points, HGU during a portal glucose infusion was significantly lower in OLETF than in LETO rats (8 weeks, 0.9 +/- 0.2 v 2.3 +/- 0.5, P < .01; 14 weeks, 0.8 +/- 0.3 v 1.4 +/- 0.3, P < .05; 28 weeks, 0.7 +/- 0.2 v 1.4 +/- 0.3 mg x kg(-1) x min(-1), P < .01). Fasting plasma free fatty acid (FFA) levels were not significantly different between OLETF and LETO, except at 8 weeks. Suppression of plasma FFA levels by endogenous insulin during a portal glucose infusion was impaired in OLETF rats compared with LETO rats. In summary, this study demonstrates that derangement of hepatic glucose handling, such as increased basal HGP and decreased HGU, is observed in obese NIDDM model OLETF rats at the prediabetic phase when hyperglycemia is still not apparent. Furthermore, these derangements may be accompanied by impaired lipid metabolism.

Reduction in brain-derived neurotrophic factor protein level in the hippocampal CA1 dendritic field precedes the delayed neuronal damage in the rat brain

Utilizing a specific polyclonal antibody against a peptide unique for brain-derived neurotrophic factor (BDNF), we investigated the regional and temporal profiles of immunoreactivity of the BDNF protein in the rat hippocampus after transient forebrain ischemia. The pattern of immunoreactivity for the BDNF receptor (TrkB) was also examined and compared with that for BDNF. In the early phase after ischemia, we observed a distinct regional difference in immunoreactivity between the pyramidal cell layer and the stratum radiatum of the CA1 subfield. In the pyramidal cell layer, there was a rapid and transient increase in the positive immunostaining for both BDNF and TrkB. By contrast, in the stratum radiatum there was a marked decrease in BDNF immunoreactivity, but not one in that of TrkB. One week after ischemia, high immunoreactivity for both BDNF and TrkB was observed in the reactive astrocytes in the dendritic field of the CA1 subfield. These findings suggest that a transport of BDNF from the neuronal soma to the dendrites of the stratum radiatum might be ceased after the ischemic insult. Thus, a dysfunctional autocrine mechanism of BDNF within the CA1 neuron may be involved in the pathogenesis of selective neuronal damage after ischemia.

[Correlation between pyrimidine nucleoside phosphorylase (PyNPase)/platelet-derived endothelial cell growth factor and histological prognostic factor, and influences of 5'-deoxy-5-fluorouridine (5'-DFUR) administration on PyNPase levels. 5'-DFUR Joint Research Group in the Osaka Area for Gastric Cancer]

PURPOSE

Pyrimidine nucleoside phosphorylase (PyNPase), among which thymidine phosphorylase (dThdPase) exists mainly in human tumor tissues, is an enzyme to convert 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil. Recently, it was reported that dThdPase was identical to platelet-derived endothelial cell growth factor, angiogenetic factor. Therefore, we expect that there is possibility of dThdPase being a prognostic factor.

METHODS

We investigated for a possible correlation between PyNPase activities in tumor tissues and prognostic factors of histological findings, examined the influences of preoperative oral 5'-DFUR administration to PyNPase levels and investigated for a correlation between HPLC methods and ELISA methods in patients with gastric cancer.

RESULTS

Higher levels of PyNPase were observed in patients with advanced t,n,v, and ly factors. PyNPase levels decreased by 5'-DFUR in patients with differentiated cases. A high correlation was found between HPLC and ELISA methods.

CONCLUSION

This study suggests that we must investigate possibility of PyNPase being a prognostic factor in more detail.

Pioglitazone enhances splanchnic glucose uptake as well as peripheral glucose uptake in non-insulin-dependent diabetes mellitus. AD-4833 Clamp-OGL Study Group

To evaluate the effect of pioglitazone on insulin resistance in non-insulin-dependent diabetes mellitus (NIDDM) patients, a double-blind placebo-controlled trial was carried out with 30 NIDDM patients. Twenty-one subjects, three on diet alone and 18 on sulfonylurea (SU), orally received 30 mg pioglitazone once daily for 12 weeks. Nine subjects, one on diet alone and eight on SU, received a matching placebo once daily for 12 weeks. Euglycemic (5.2 mmol/l) hyperinsulinemic (1200 pmol/l) clamp combined with an oral glucose load (OGL) was performed before and after 3-month treatment with pioglitazone or placebo to determine insulin-stimulated glucose disposal and splanchnic glucose uptake (SGU). No significant differences existed in the patients' characteristics, including age and body mass index, between the two study groups. The pioglitazone treatment increased the mean glucose infusion rate (GIR) prior to OGL from 8.2 +/- 2.2 to 9.2 +/- 2.0 mg/kg.min (mean +/- SD, P = 0.003) and increased the SGU rate from 28.5 +/- 19.4 to 59.4 +/- 27.1% (P = 0.010). The placebo treatment produced no significant changes in either GIR or SGU after treatment. A significant difference (P = 0.042) was observed in change of SGU between the pioglitazone and placebo treatment groups. In conclusion, the results indicate that pioglitazone is effective for ameliorating insulin resistance in NIDDM by enhancing SGU as well as peripheral glucose uptake.

Direct fractionation of proteins in particle-containing feedstocks by a filter paper pieces-based DEAE-cellulose column chromatography. Rapid, robust and low-cost capturing procedure for protein

Filter paper pieces-based (FPB) DEAE-celluloses was prepared for direct fractionation of proteins in particle-containing feedstocks. FPB DEAE-cellulose has a protein binding capacity equivalent to that of commercially available DEAE-cellulose. Crude extracts from porcine intestine and kiwi fruit pulp, which were unmanageable by commercially available chromatographic media due to rapid clothing, could be directly fractionated with FPB DEAE-cellulose column. In addition, effluents from an FPB DEAE-cellulose column were extensively clarified. The present approach can be used as a rapid, robust and low-cost capturing step for protein from particle-containing feedstocks.

TAS-301, an inhibitor of smooth muscle cell migration and proliferation, inhibits intimal thickening after balloon injury to rat carotid arteries

The purpose of this study was to determine the efficacy and the possible mechanism of action of a recently synthesized drug, TAS-301 [3-bis (4-methoxyphenyl)methylene-2-indolinone], on intimal formation in comparison with those of tranilast, the clinical efficacy of which was reported earlier. Rat carotid arteries were injured using a balloon catheter. Neointimal thickening, measured 14 days after injury, was reduced by the oral administration of TAS-301 in a dose-dependent fashion (3-100 mg/kg), and the effect of TAS-301 at a dose of 100 mg/kg was significantly greater than that of tranilast (300 mg/kg). Fewer cells were found on the intima of balloon-injured arteries of TAS-301-treated rats than on arteries of tranilast-treated rats. In an in vitro assay, TAS-301 inhibited the migration of smooth muscle cells (SMCs) stimulated by platelet-derived growth factor-BB, insulin-like growth factor-1 or heparin-binding epidermal growth factor-like growth factor. In addition, TAS-301 and tranilast reduced the proliferation of medial and intimal SMCs at 4 and 8 days, respectively, after the injury. In vitro, TAS-301 inhibited basic fibroblast growth factor-induced proliferation of SMCs dose dependently. These findings indicate that TAS-301 shows a higher inhibitory potency on intimal formation than tranilast due to inhibition of both migration of medial SMCs and proliferation of medial and intimal SMCs. Our results suggest that further evaluation of TAS-301 as an inhibitor of postangioplasty intimal thickening is warranted.

[A successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy by mediastinoscopy]

We reported a successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy. This 59-year-old male was treated by drainage with mediastinoscopy and repeated wash-out under bronchoscopy, because we could not use the omentum and he was the poor-risk patient. The trancheal fistula was obliterated bronchoscopically, 4 months after the mediastinoscopy. We believe that this method (abscess drainage with mediastinoscope and wash-out repeatedly) is useful for those who has broncheal fistula after esophagectomy.

[Mediastinoscopic diagnosis and drainage of pericardial diverticulum--a case report]

A 38-year-old male was suspected of having an enlarged pretracheal lymph node on chest CT scan. At mediastinoscopy, a cystic lesion was recognized, and showed repeated dilatation and contraction synchronously with the cardiac beat. Pneumopericardium was demonstrated by intraoperative pneumocystography. The cystic lesion was diagnosed as pericardial diverticulum. The diverticular wall was partially resected for drainage of the pericardial fluid. Mediastinoscopy as a less invasive procedure may be useful for the differential diagnosis of adenopathies, and in case of lesion such as a small pericardial diverticulum may allow treatment.

High plasma free fatty acids decrease splanchnic glucose uptake in patients with non-insulin-dependent diabetes mellitus

It has been proposed that high plasma free fatty acid (FFA) levels observed in patients with non-insulin dependent diabetes mellitus (NIDDM) contribute to the development of their insulin resistance. We examined patients with NIDDM to find whether maintaining plasma FFA levels in the fasting range with a euglycemic hyperinsulinemic clamp combined with an oral glucose load (clamp OGL) would affect insulin-mediated peripheral glucose uptake (PGU) and splanchnic glucose uptake (SGU). Nine NIDDM subjects (age, 55 +/- 3 years; duration of diabetes, 11 +/- 2 years; body mass index, 21.0 +/- 0.4 kg/m2; hemoglobin A1c, 9.0 +/- 0.3%; fasting plasma glucose, 9.4 +/- 3.0 mmol/l, means +/- SEM) were hospitalized and treated with diet, oral hypoglycemic agents or insulin for at least 2 weeks to maintain fasting plasma glucose < 8 mmol/l. All the patients were subjected to two different protocols in a random order. On one protocol, under the hyperinsulinemic condition, FFAs were maintained at the their fasting levels (1.19 +/- 0.08) by triglyceride emulsion infusion (Lipid infusion study, L), and on the other protocol, FFAs were made to fall (0.26 +/- 0.06 mmol/l) with saline instead of triglyceride emulsion infusion (Saline infusion study, S). During euglycemic (L, 5.4 +/- 0.2; S, 5.1 +/- 0.2 mmol/l) hyperinsulinemic (L, 1377 +/- 108; S, 1328 +/- 67 pmol/l) clamp, high FFA levels significantly reduced PGU (L, 26.7 +/- 3.6; S, 32.1 +/- 3.4 mumol.kg-1.min-1, P < 0.05) and SGU (L, 12.1 +/- 4.2; S, 27.5 +/- 5.6%, P < 0.05). In conclusion, high FFA levels in patients with NIDDM impaired insulin-mediated glucose uptake in the splanchnic as well as peripheral tissues.

Characteristics of protrusive and lateral excursions of the mandible in children with the primary dentition

This study characterizes the mandibular protrusive and lateral excursions of children with primary dentition. With use of a Selspot system, the protrusive and lateral excursions of nine children with the primary dentition and nine adults with the permanent dentition were measured and compared. This system was able to analyse the simultaneous movements of multiple points on the mandible of a subject in three dimensions. Furthermore, the system proved appropriate for use in young children because of the small burden imposed on them during the measurements. Using this subject-friendly system, the directions of the mandibular excursion for five reference points on the mandibular dental arch at each measurement distance (i.e. at 0.5 mm intervals) for three projected angles (frontal, sagittal and horizontal) were calculated. From the results it was found that the excursions of the primary dentition can move more horizontally and more forward with small descent compared with the permanent dentition. The underlying reason for these findings may be physiological growth, maturation, and adaptation of the occlusal function.

[Drug delivery system for diabetes]

Long-term intensified insulin therapy composing of multiple insulin injection and self-blood glucose monitoring enables glycemic control of insulin-requiring diabetics. For reducing inconvenience of this therapy, several delivery route of insulin are under investigation. Nasal administration of insulin aerosol effectively controlled insulin-dependent diabetics for up to 6 months because its high bioavailability and rapid absorption. By means of ionophoresis or ultrasound approach, insulin was shown to be absorbed transdermally. Polymer containing modified insulin and immobilized enzyme could increase insulin release against hyperglycemia. These new approach of insulin delivery might increase convenience of insulin administration.

Interferon induces insulin resistance in patients with chronic active hepatitis C

AIM/METHODS

To elucidate the metabolic effect of interferon alpha, the following tests were performed on 14 patients with chronic active hepatitis C before and after interferon therapy (6 million units/day for 2 weeks): (1) oral glucose tolerance tests to measure insulin secretion; (2) euglycemic hyperinsulinemic clamp with oral glucose load to measure peripheral and hepatic insulin sensitivity (splanchnic glucose uptake); and (3) measurements of plasma levels of glucoregulatory hormones.

RESULTS

The oral glucose tolerance test showed that a 2-week treatment with interferon did not induce apparent change in plasma glucose and insulin profiles. Nevertheless, interferon therapy worsened insulin-mediated glucose uptake in the peripheral tissues by 17% from 44.4+/-3.2 to 37.3+/-3.0 micromol x kg(-1) x min(-1) (p<0.05). Furthermore, interferon therapy significantly decreased splanchnic glucose uptake by 38% from 47+/-2% to 29+/-3% (p<0.01). No changes were noted for plasma glucoregulatory hormones, such as epinephrine, norepinephrine, cortisol and growth hormone, after interferon therapy.

CONCLUSIONS

These results indicate that interferon therapy for 2 weeks induces insulin resistance in the splanchnic, as well as peripheral tissues, in patients with chronic active hepatitis C. Therefore, more careful observation may be needed during interferon therapy in subjects with impaired glucose tolerance.

[Mediastinoscopic drainage for descending necrotizing mediastinitis]

A case of descending necrotizing mediastinitis that was treated by mediastinoscopic drainage is reported. The patient was a 56-year-old diabetic woman. A hypopharyngeal abscess extended to the mediastinum through the neck. No septic condition was noted. Chest CT showed that the abscess reached 4 cm below the tracheal bifurcation. Pus was drained under direct observation by mediastinoscopy, and a drain was placed in an appropriate position. After operation, lavage was performed through the drain, and cure was achieved on the 42nd postoperative day. This technique should be considered as surgical treatment for descending necrotizing mediastinitis in the absence of serious complication such as sepsis, because it has a more reliable drainage effect than the conventional transcervical method, and because it is less invasive than thoracotomy.

Expression of interleukin-8 in human glomerulonephritis

Interleukin-8 (IL-8) is a cytokine, which possesses both chemotactic and activating properties for neutrophils, lymphocytes and basophils. Various evidence has indicated IL-8 to be implicated in the pathophysiology of immune-mediated renal diseases. We thus examined the expression of IL-8 in renal diseases. We detected the expression of IL-8 both in mRNA and the protein levels in renal biopsy specimens obtained from patients with IgA nephropathy and lupus nephritis. A significant correlation was found between the expression of IL-8 mRNA and the number of neutrophils in the glomerulus. We also found a negative correlation between the expression of IL-8 mRNA and creatinine clearance. Our study thus suggested IL-8 to be involved in the pathophysiology of proliferative glomerulonephritis.

Prior muscular contraction enhances disposal of glucose analog in the liver and muscle

To noninvasively investigate in vivo glucose disposal in muscle and liver after exercise, 19F magnetic resonance spectroscopy (19F-MRS) was applied using 3-fluoro-3-deoxy-D-glucose (3FDG) as a metabolic probe. After 30 minutes of muscle contraction of rabbit hindlimb by a 1-Hz electrical stimulation, 3FDG 250 mg/kg was injected intravenously and 19F-MRS was performed on the postcontracted hindlimb or the liver. Rabbits subjected to muscle contraction showed 1.5- and 1.7-fold higher peaks for 3FDG signal intensity in the liver and muscle than those not subjected to it. 3FDG was converted to 3-fluoro-3-deoxy-gluconic acid (3FGA) in the muscle and liver, and 3FDG oxidation was not affected by muscle contraction. During intraportal 3FDG infusion for 120 minutes at a dose of 2 mg x kg-1 x min-1 after termination of muscle contraction, the postcontracted rabbits showed a continuous increase in the signal intensity of 3FDG and a 2.1-fold higher total signal intensity of 3FDG than those not subjected to muscle contraction. In conclusion, 19F-MRS allows direct noninvasive observation of 3FDG disposal in rabbit muscle and liver. The increased intensity of 3FDG in the liver after muscle contraction suggests that exercise enhances disposal of the glucose analog in the liver, as well as in muscle, and these effects persist for at least 2 hours after exercise.

[Mediastinal bronchogenic cyst associated with high serum level of CA19-9--a surgical case report]

We reported a case of mediastinal bronchogenic cyst in a patient with a high serum level of CA19-9. The patient, a 41-year-old man, presented with a complaint of persistent fever. Chest X-ray examination, computed tomography and magnetic resonance imaging showed a subcarinal mass shadow which was diagnosed preoperatively as a bronchogenic cyst. The serum level of CA19-9 was 73 U/ml. The cyst was partially removed via right thoracotomy. Histopathological findings were compatible with bronchogenic cyst. The CA19-9 level in the specimen was 134,00 U/ml. The serum level of CA19-9 decreased to normal postoperatively. The postoperative course was uneventful.

Role of Helicobacter pylori in residual gastritis after distal partial gastrectomy

We studied the relation between Helicobacter pylori and residual gastritis in 28 patients with gastric cancer on whom distal partial gastrectomy with Billroth I reconstruction was performed over a 13-month period. They were subjected to serologic testing along with endoscopic and histologic examinations before operation and at 3, 6, and 12 months after operation. Anti-H. pylori immunoglobulin G (IgG) and serum gastrin levels were measured by serologic tests. The presence or absence of gastritis was determined endoscopically, and gastric mucosal hexosamine levels were determined. Gastritis was measured quantitatively by histologic examination in specimens taken from the gastric mucosa using Rauws' score. After the initial histologic evaluation we divided the H. pylori-positive patients into two groups: those with a Rauws' score of 0 to 3 ("weak" gastritis group), and those with a Rauws' score of 4 to 10 ("strong" gastritis group), allowing us to compare the results of our three postoperative histologic examinations of the two groups for possible significant differences. Our endoscopic examinations showed gastric mucosal inflammatory changes in both H. pylori-positive and H. pylori-negative patients at 3, 6, and 12 months after operation, but there was no significant difference between these two groups at any point. During the histologic examinations, however, anti-H. pylori IgG assay had become negative in several patients in the "weak" gastritis group at 3 months after operation and was found to have become negative in 78% of all patients in that group 12 months after operation. In contrast, in the "strong" gastritis group H. pylori infection was still evident in the patients 12 months after operation, suggesting that "strong" histologic gastritis may have some connection to H. pylori infection, whereas "weak" histologic gastritis has no such connection. The gastric mucosal hexosamine level was higher in the "weak" gastritis group than in the "strong" gastritis group both before operation and at 6 and 12 months, indicating some relation between gastric inflammatory changes and hexosamine levels in gastric mucosa. It further suggested the possibility that H. pylori plays a role in destroying gastric mucosa by depleting mucin, thus acting as one (though not the only) cause of residual gastritis after distal partial gastrectomy. In conclusion, we found evidence that there is a relation between residual gastritis and H. pylori infection, but H. pylori is not the sole cause of residual gastritis after gastric surgery. A causal relation is difficult to detect by simple analysis of histologic findings or by endoscopic observation or clinical symptoms alone.

Expression of heparin-binding epidermal growth factor-like growth factor during pancreas development. A potential role of PDX-1 in transcriptional activation

The development of the pancreas appears to be regulated by various growth factors. We report here the expression of heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) in the developing pancreas. Immunostaining of fetal and neonatal rat pancreata, in which endocrine cells are visible as cell clusters often associated with primitive ducts or ductular cells, revealed that most of the cluster-forming cells and primitive ducts or ductular cells express HB-EGF protein. In contrast, the exocrine pancreas lacked HB-EGF expression. Based on findings that the expression pattern was similar to that of the homeodomain-containing transcription factor PDX-1 (IDX-1/STF-1/IPF1) and that the regulatory region of the HB-EGF gene contained sequences similar to the PDX-1-binding A element, we examined whether PDX-1 could be a potential activator of HB-EGF gene expression. The results of reporter gene analyses suggested that the HB-EGF gene promoter is PDX-1-responsive and that the activity of the promoter in pancreatic beta cell-derived betaTC1 cells depends on the PDX-1 binding site-like sequences. Gel-mobility shift analyses using an anti-PDX-1 antibody indicated that PDX-1 is a specific and dominant binding factor for an A element-like sequence in the HB-EGF gene. These observations suggest the possible involvement of HB-EGF in pancreas development. While PDX-1 is essential for pancreas development, HB-EGF may function as a mediator of PDX-1 and thus be involved in the development of the endocrine pancreas.

Pioglitazone (AD-4833) ameliorates insulin resistance in patients with NIDDM. AD-4833 Glucose Clamp Study Group, Japan

We evaluated the effect of pioglitazone, a thiazolidinedione compound, on insulin-stimulated glucose disposal (Rd) and its efficacy on carbohydrate and lipid metabolism in patients with non-insulin-dependent diabetes mellitus (NIDDM). Twenty NIDDM subjects (mean age 58.2+/-9.4 year, body mass index (BMI) 23.9+/-3.4 kg/ m2 (mean+/-S.D.], three with diet alone, 17 with sulfonylureas [SU]) participated in this trial from five diabetes clinics. Euglycemic (5.3 mmol/liter) hyperinsulinemic (insulin infusion rate 9 micromoles x kg[-1] x min[-1]) clamp studies were performed before and after oral administration of pioglitazone (30 mg/day) for 87+/-10 days. The Rd significantly improved from 5.5+/-2.5 to 8.3+/-3.1 mg x kg(-1) x min(-1). Fasting plasma glucose (FPG) level significantly decreased from 11.0+/-2.0 mmol/liter to 8.9+/-1.1 mmol/liter with a significant improvement in the hemoglobin A1c level from 9.2+/-1.8% to 8.3+/-1.5%. Fasting serum insulin and C peptide levels decreased from 83+/-36 pmol/liter and 0.62+/-0.21 nmol/liter to 66+/-29 pmol/liter and 0.58+/-0.25 nmol/liter, respectively. Fasting serum triglyceride and free fatty acids levels significantly decreased with concomitant increase of fasting serum HDL-cholesterol levels from 1.2+/-0.2 to 1.5+/-0.3 mmol/liter. The change in Rd between before and after pioglitazone administration correlated with baseline values of FPG (rho=0.633), serum insulin (rho=0.653), BMI (rho=0.456), Rd (rho 0.558) and 1,5-AG (rho=-0.522). These data indicate that pioglitazone enhances the insulin action in NIDDM patients on diet alone or SU, and thereby improves both plasma glucose level and lipid profiles.

The Arg192 isoform of paraoxonase with low sarin-hydrolyzing activity is dominant in the Japanese

The high-density-lipoprotein-associated enzyme paraoxonase, which has a role in the detoxification of organophosphorus compounds, is known to be polymorphic in humans. The Arg192 isoform of paraoxonase hydrolyzes paraoxon more rapidly than the Gln192 isoform. However, with respect to the hydrolysis of toxic nerve agents, such as diazoxon, soman, and sarin, the Arg192 isoform displays a lower activity than the other isoform. To evaluate the possibility that the genetic polymorphism was involved in the aggravated extent of human injury in the sarin gas poisoning incident in the Tokyo subway in March 1995, we investigated the prevalance of this polymorphism in the Japanese population. We found that the Arg192 allele is more common in the Japanese (allele frequency: 0.66) than in people of other races (ranging 0.24-0.31). In the Japanese, 135 out of the 326 subjects (41.4%) investigated were homozygous for the Arg192 allele, which shows a very low hydrolysis activity for sarin. Thus, there seems to be a racial difference in vulnerability to toxic nerve agents, such as sarin. The dominance of the Arg192 allele in the Japanese population probably worsened the tragedy of March 1995 in the Tokyo subway.

Bcl-2 expression and apoptosis in nephrotoxic nephritis

The product of the Bcl-2 proto-oncogene has been shown to prolong cell survival by preventing apoptosis in several cell lineages. To investigate the regulatory mechanisms of apoptosis in glomerulonephritis, we examined the expression pattern of the Bcl-2 protein together with cellular events in rat nephrotoxic nephritis. Bcl-2 protein and proliferating cell nuclear antigen were detected in glomeruli by immunohistochemistry. Morphologic changes of apoptosis were identified by electron and light microscopy and an in situ DNA nick end labeling method. The first (heterologous) phase began with significant neutrophil infiltration shortly after the injection of nephrotoxic serum. Both Bcl-2 expression and the number of proliferating cells in the glomeruli were at maximum at 24 h in the heterologous phase. Glomerular hypercellularity with an influx of macrophages and the number of apoptotic glomerular cells peaked on day 14 in the second (autologous) phase. Glomerulonephritis resolved after that. These results suggest that overexpression of the Bcl-2 protein may play a role in glomerular cell survival and exacerbation of glomerulonephritis. Apoptosis may occur as an active mechanism in the resolution of the autologous phase in nephrotoxic nephritis.

Pharmacological profile of TH-142177, a novel orally active AT1-receptor antagonist

The pharmacological properties of TH-142177 (N-n-butyl-N-[2'-(1-H-tetrazole-5-yl) biphenyl-4-yl]-methyl-(N-carboxymethyl-benzylamino)-acetamide), a novel antagonist of the angiotensin II (AII) AT1 receptor, were studied in vitro and in vivo, and compared to those of losartan. In the rat isolated aorta, TH-142177 produced parallel shifts to the right of the concentration-response curves for AII-induced contractions without affecting the maximal response (pA2 = 9.07). The inhibitory potency of TH-142177 in the aorta was about three times greater than that of losartan. TH-142177 completely inhibited the specific binding of [125I]AII to AT1 receptor in rat aortic membranes (Ki = 1.6 x 10(-8) M), whereas specific [125I]AII binding to AT2 receptor in bovine cerebellum and human myocardium was not affected by concentrations of TH-142177 up to 10(-5) M. Losartan also inhibited the [125I]AII binding to rat aortic membranes (Ki = 2.2 x 10(-8) M). Following the intravenous administration to anesthetized normotensive rats, TH-142177 dose-dependently inhibited the increase in systolic blood pressure induced by an intravenous bolus injection of AII that was 1.5 times less potent than losartan. Furthermore, the oral administration of TH-142177 to conscious renal hypertensive rats exerted a dose-dependent reduction of systolic blood pressure without significantly effecting the heart rate. TH-142177 was at least three times more potent than losartan. These results demonstrate that TH-142177 is a potent and selective antagonist of AT1 receptors and by oral administration has a long-lasting antihypertensive activity.

Suppression of transcription factor PDX-1/IPF1/STF-1/IDX-1 causes no decrease in insulin mRNA in MIN6 cells

The insulin gene transcription factor PDX-1/IPF1/STF-1/ IDX-1 plays a key role in directing beta cell-specific gene expressions. Recently, impairment of PDX-1 expression or activity has been observed in beta cell-derived HIT cells cultured under high glucose concentrations, and this has been suggested as a possible cause of the decrease in insulin gene transcription. To investigate the pathophysiological significance of PDX-1 as a determinant of the rate of insulin gene transcription, we suppressed its expression in beta cell-derived MIN6 cells using an antisense oligodeoxynucleotide (ODN) and searched for possible changes in the beta cell-specific gene expression. Treatment of MIN6 cells with an 18-mer phosphorothioate ODN complementary to a sequence starting at the translation initiation codon of PDX-1 caused a potent, concentration-dependent reduction in PDX-1 expression; addition of 2 microM antisense ODN could reduce PDX-1 expression to 14+/-4% of the control. There was also a decrease in its DNA binding to the insulin gene A element. Despite such suppression of PDX-1, Northern blot analysis revealed no decrease in the amount of insulin mRNA in the MIN6 cells. Similarly, no changes were detected in the transcription of the glucokinase or islet amyloid polypeptide gene, for which PDX-1 was shown to function as a transcription factor. Thus, our findings dispute the physiological significance of PDX-1 in determining the rate of insulin gene transcription. This means that other components constituting the transcription-controlling machinery need to be evaluated in order to understand the molecular basis of impaired insulin biosynthesis such as that observed due to glucose toxicity.

[Allogeneic peripheral blood stem cell transplantation for multiple myeloma]

We report here with a 46-year-old man with refractory multiple myeloma receiving allogeneic peripheral blood stem cell transplantation from his HLA-matched brother. The preparative regimen consisted of TBI (12Gy), VP16 (15 mg/kg) and cyclophosphamide (120 mg/kg). GVHD prophylaxis consisted of cyclosporin A and short course of methotrexate. The donor received G-CSF at 10 micrograms/kg/day for 5 consecutive days and underwent leukapheresis on days 5 and 6. The neutrophil recovery to 500/microliter and platelet recovery to 20,000/microliter were day 12 and day 15, respectively. The patient is currently well with no GVHD or graft failure and a complete donor's chimerism.

Demonstration of two different processes of beta-cell regeneration in a new diabetic mouse model induced by selective perfusion of alloxan

To clarify the regeneration process of pancreatic beta-cells, we established a new mouse model of diabetes induced by selective perfusion of alloxan after clamping the superior mesenteric artery. In this model, diabetes could be induced by the destruction of beta-cells in alloxan-perfused segments, while beta-cells in nonperfused segments were spared. Intraperitoneal glucose tolerance tests showed glucose intolerance, which gradually ameliorated and was completely normalized in 1 year with a concomitant increase of insulin content in the pancreas. Histological examination showed neo-islet formation in the alloxan-perfused segment and the proliferation of spared beta-cells in the nonperfused segment. In the alloxan-perfused segment, despite a marked reduction of islets in size and number at an early stage, both the number of islets, including islet-like cell clusters (ICCs), and the relative islet area significantly increased at a later stage. Increased single beta-cells and ICCs were located in close contact with duct cell lining, suggesting that they differentiated from duct cells and that such extra-islet precursor cells may be important for beta-cell regeneration in beta-cell-depleted segment. In addition to beta-cells, some nonhormone cells in ICCs were positive for nuclear insulin promoter factor 1, which indicated that most, if not all, nonhormone cells positive for this factor were beta-cell precursors. In the nonperfused segment, the islet area increased significantly, and the highest 5-bromo-2-deoxyuridine-labeling index in beta-cells was observed at day 5, while the number of islets did not increase significantly. This indicated that the regeneration of islet endocrine cells occurs mostly through the proliferation of preexisting intra-islet beta-cells in the nonperfused segment. In conclusion, the regeneration process of beta-cells varied by circumstance. Our mouse model is useful for studying the mechanism of regeneration, since differentiation and proliferation could be analyzed separately in one pancreas.

Augmentation of hepatic glucose uptake by a positive glucose gradient between hepatoportal and central nervous systems

To determine the role of the glucose gradient between the hepatoportal system (HPS) and the central nervous system (CNS) in regulating hepatic glucose uptake, experiments were conducted with seven conscious dogs using a hepatic venous catheterization technique. With the infusion of somatostatin (0.8 microg x kg(-1) x min(-1)), glucagon (0.65 ng x kg(-1) x min(-1)), and insulin (27 pmol x kg(-1) x min(-1)), arterial glucose levels could be maintained at 8 mmol/l by adjusting the intravenous glucose infusion (G(inf)) according to the following three periods: 1) peripheral glucose infusion period (PE), G(inf) alone; 2) portal glucose infusion period (PO), G(inf) plus constant glucose infusion into the portal vein (GIR(PV), 55.6 micromol x kg(-1) x min(-1)); 3) portal and brain glucose infusion period (PO+CNS), G(inf) and GIR(PV) plus additional glucose infusion into the unilateral carotid and vertebral arteries to abolish the positive glucose gradient between HPS and CNS. Arterial plasma glucose levels were clamped during the three periods (8.1 +/- 0.1, PE; 8.2 +/- 0.1, PO; 8.2 +/- 0.1 mmol/l, PO+CNS). During PO, when a positive glucose gradient was promoted between HPS and CNS, the net hepatic glucose balance (NHGB) determined by the difference between hepatic glucose inflow and outflow was significantly lower than that of PE (-41.5 +/- 5.3, PO vs. -7.5 +/- 3.4 micromol x kg(-1) x min(-1), PE; P < 0.01). However, this decrease in the NHGB significantly increased during PO+CNS, when the glucose gradient between HPS and CNS was minimized, compared with PO (-21.7 +/- 3.2 micromol x kg(-1) x min(-1), P < 0.05). We conclude that a positive glucose gradient between HPS and CNS is an important regulatory factor of hepatic glucose uptake, but other factors also play important roles because minimizing the glucose gradient between HPS and CNS diminished the net hepatic glucose uptake by 50%.

Mediastinoscopic extirpation of mediastinal ectopic parathyroid gland

We report a case of a 50-year-old man with hyperparathyroidism secondary to chronic renal failure who underwent extirpation of a mediastinal ectopic parathyroid gland by a transcervical approach under mediastinoscopy. This procedure provides an excellent approach to the mediastinal ectopic parathyroid gland, and is less invasive than median sternotomy or thoracotomy.

New therapeutic possibility of blocking cytokine-induced neutrophil chemoattractant on transient ischemic brain damage in rats

Earlier we indicated that neutrophilic invasion into cerebral parenchyma is an important step in rat cerebral ischemia-reperfusion injury and the production of chemotactic factors, cytokine-induced neutrophil chemoattractant (CINC) precede the neutrophilic invasion. The aim of the present study was to evaluate the role of CINC production and the therapeutic possibility of blocking CINC activity in the transient ischemic brain damage in rats. Focal transient ischemia was produced by intraluminal occlusion of the right middle cerebral artery for 60 min. An enzyme immunoassay was used to measure the brain concentration of CINC and myeloperoxidase activity in ischemic areas was measured as a marker of neutrophilic accumulation. An immunohistochemical staining technique was used to detect the immunopositive cells for anti-CINC antibody. Further, application of anti-CINC antibody or anti-neutrophil antibody to rats was used to evaluate the role of CINC production. In ischemic areas, CINC production was detected and peaked 12 h after reperfusion, which followed 60 min of ischemia. Intraperitoneal injection of anti-neutrophil antibody 24 h before and immediately after reperfusion significantly reduced the brain water content and partially reduced the CINC production in ischemic areas. Further, immunohistochemical staining showed that anti-CINC antibody was found on the endothelial surface of venules and on parts of neutrophils that had invaded the ischemic area 6 to 24 h after reperfusion. Also, treatment with anti-CINC antibody reduced ischemic edema formation 24 h after reperfusion and the size of infarction areas 7 days after reperfusion. It thus appears that CINC, mainly produced by endothelium activated by factors released from neutrophils, plays an important role in ischemic brain damage. Furthermore, the blocking of CINC activity with antibody suggests an immuno-therapeutic approach to the treatment of stroke patients.

Ultra-high-resolution scanning electron microscopy of mitochondria and sarcoplasmic reticulum arrangement in human red, white, and intermediate muscle fibers

BACKGROUND

Human skeletal muscle fibers are the red, white, and intermediate fibers. They differ in their mitochondrial structure and enzyme activity. Scanning electron microscopy (SEM) was used on specially prepared specimens to determine the distinctive features of mitochondria and sarcoplasmic reticulum (SR) in each fiber type.

METHODS

Specimens of human limb muscles were glutaraldehyde fixed, frozen, fractured, and macerated by the aldehyde-osmium-DMSO-osmium procedure to expose large areas of mitochondria and SR. Osmium-hydrazine-impregnated tissues were examined without metal coating by ultra-high-resolution SEM.

RESULTS

In white fibers, paired long, thin mitochondria encircled myofibrils at the I-band level. In red fibers, the paired rows of stubby mitochondria at the I-band level were often connected across the A-band to the next row of mitochondria by a slender mitochondrial stalk. Intermediate fiber mitochondria resembled those in red fibers but were longer and thinner. Intermyofibrillar mitochondrial columns were most common in red fibers. All three muscle types had T-tubules along the A-I junction level, and small periodic terminal cisternae formed triads or dyads. Sarcotubules from terminal cisternae formed continuous three-dimensional networks at the I-band level, but intermittent straight sarcotubules, narrow two-dimensional networks, and some axial tubules traversed the A-band. The subsarcolemmal space had continuous two-dimensional SR at the H-band level and a coarse SR network at the I-band. These two SR networks were connected by single A-band sarcotubules.

CONCLUSIONS

Mitochondrial shape and configuration were distinctive for each human skeletal muscle fiber type, but the SR was similar in all muscles examined.

Sleep characteristics of Japanese working men who score alexithymic on the Toronto Alexithymia Scale

This study examined the relationship of sleep characteristics including insomnia with scores on alexithymia in a sample of 171 Japanese working men. Levels of nonrestorative sleep and daytime sleepiness reported on a sleep questionnaire were significantly associated with scores on Depression and Confusion on the Profile of Mood States for Japanese men who had a high mean score on the Toronto Alexithymia Scale.

Ultra-high-resolution scanning electron microscopy of the sarcoplasmic reticulum of the rat atrial myocardial cells

BACKGROUND

The sarcoplasmic reticulum (SR) of mammalian ventricular and atrial muscles share common features but also differ because T-tubules are rare and extended junctional SR is exclusively seen in the atrium. This scanning electron microscope (SEM) study was undertaken to clarify the three-dimensional organization of the rat atrial SR system. Specific preparations were examined with an ultra-high-resolution SEM.

METHODS

Fixed right rat atria were frozen, fractured, and macerated by the aldehyde-osmium-DMSO-osmium method to remove myofibrils and cytoplasmic matrix. Left exposed were mitochondria, SR, and sarcolemma. Dried specimens were then impregnated by osmium-hydrazine and examined without metal coating.

RESULTS

In place of conventional T-tubules, a prominent type of sarcotubules, Z-tubules, were found at the Z-line level. Branches from these tubules joined the cisternal SR, which was 100-300 nm in diameter and localized near the Z-line, and formed extensive SR meshworks and polygonal patches. Bulbous swellings, the corbular SR, were also evident. Sarcotubular reticulum completely surrounded each myofibril. The intermyofibrillar SR, especially Z-tubules, joined the peripheral subsarcolemmal SR, which was also arranged as a meshwork and was closely apposed to the sarcolemma.

CONCLUSIONS

These SEM observations confirm the organization of the rat atrial SR system and present new, detailed, three-dimensional images of Z-tubules, cisternal SR, extended junctional SR, and peripheral SR, which provide further structural insight.

Ultra-high-resolution scanning electron microscopy of the continuity of cytoplasmic and luminal membranes in frog oxyntic cells

BACKGROUND

Despite numerous previous studies, the presumed continuity of the luminal and tubulovesicular membranes in frog oxyntic (oxyntico-peptic) cells remains to be convincingly demonstrated. This study was undertaken to clarify this question by ultra-high-resolution scanning electron microscopy of specially prepared frog stomach specimens before and during histamine stimulation.

METHODS

Fasted Japanese meadow frogs stimulated with histamine were used. Oxyntic cell cytoplasmic matrix was removed by the aldehyde-osmium-DMSO-osmium maceration procedure and impregnated with osmium-hydrazine. Specimens were examined without metal coating.

RESULTS

In the resting oxyntic cell, the luminal membrane had closely packed surface folds forming a rather flat surface with a few short microvilli. In the cytoplasm, flattened 200-500 nm vesicles were interconnected by numerous slender 20-60 nm tubules forming the tubulovesicular network. Occasional slender tubular branches were found in continuity with the luminal membrane. After histamine stimulation, the number and length of microvilli and surface folds increased, whereas the tubulovesicular membrane system decreased. Sites of clear continuity between the luminal and tubulovesicular membranes were not abundant but were clearly demonstrated in histamine-stimulated oxyntic cells. The small size of the tubules connecting the tubulovesicular system to the plasma membrane renders this observation by transmission electron microscopy very difficult. In these specimens, the clear continuity of the tubulovesicular network to the luminal plasma membrane became more evident.

CONCLUSIONS

This study confirms previous findings of increased luminal membrane and depletion of the tubulovesicle system. The demonstration of continuity between these two compartments in our SEM preparations supports the hypothesis of direct transfer of tubulovesicular membrane to oxyntic cell luminal secretory membrane.

Diabetic scleredema: a case report and biochemical analysis for glycosaminoglycans

We report a patient with the typical lesions of diabetic scleredema. Histological findings of the involved skin were thickening of the dermis, depositions of mucins, and fibrosis. Biochemical analysis revealed an increase in glycosaminoglycans in the involved skin as well as in the cutaneous lupus mucinosis. Mucinous materials were composed of hyaluronic acid.

Sensitive, selective gas chromatographic-mass spectrometric analysis with trifluoroacetyl derivatives and a stable isotope for studying tissue sorbitol-producing activity

One of the major mechanisms involved in diabetic microangiopathy is considered to be an altered polyol pathway. However, clarifying the pathophysiology is difficult due to the lack of a sensitive method for measuring the reduction of glucose to sorbitol in tissue. Here we report a sensitive and selective method for polyol measurement using trifluoroacetyl (TFA) derivatives of polyols and stable isotope-labeled D-sorbitol (U-[13C]sorbitol, 13C6H14O6, 98.7%) as an internal standard. Gas chromatography-mass spectrometry (GC-MS) using an SE-30 capillary column gave elution of TFA derivatives of sugars, polyols and U-[13C]sorbitol within 8 min, with clear separation of sorbitol. In the calibration study, the coefficients of correlation between the amount of sorbitol added and that determined in standard solutions containing 0.1-8.0 nmol sorbitol, erythrocyte mixture and liver cytosol mixture were r = 0.999, r = 0.997 and r = 0.997, respectively. The precision of the GC-MS measurement of standard solution was C.V. = 4.3%. Because glucose is used as a substrate, the method can clarify the polyol pathway under physiological conditions. With this method, Km and Vmax values of the reductase in erythrocytes were 115 +/- 19 mmol/l and 4.42 +/- nmol/min/g of hemoglobin. In human liver, on the other hand, they were 755 +/- 132 mmol/l and 0.773 +/- 0.090 nmol/min/mg of protein, respectively. This difference of Km values suggested that aldehyde reductase rather than aldose reductase is mainly responsible for reducing glucose to sorbitol in the liver. In conclusion, this newly developed method offers a highly sensitive and selective procedure for measuring low concentrations of sorbitol in various tissues and cells and should enable clarification of the kinetics of glucose reduction to sorbitol, which in turn can be used to evaluate the role of an altered polyol pathway in the pathophysiology of diabetic microangiopathy.

Glycation-dependent, reactive oxygen species-mediated suppression of the insulin gene promoter activity in HIT cells

Prolonged poor glycemic control in non-insulin-dependent diabetes mellitus patients often leads to a decline in insulin secretion from pancreatic beta cells, accompanied by a decrease in the insulin content of the cells. As a step toward elucidating the pathophysiological background of the so-called glucose toxicity to pancreatic beta cells, we induced glycation in HIT-T15 cells using a sugar with strong deoxidizing activity, D-ribose, and examined the effects on insulin gene transcription. The results of reporter gene analyses revealed that the insulin gene promoter is more sensitive to glycation than the control beta-actin gene promoter; approximately 50 and 80% of the insulin gene promoter activity was lost when the cells were kept for 3 d in the presence of 40 and 60 mM D-ribose, respectively. In agreement with this, decrease in the insulin mRNA and insulin content was observed in the glycation-induced cells. Also, gel mobility shift analyses using specific antiserum revealed decrease in the DNA-binding activity of an insulin gene transcription factor, PDX-1/IPF1/STF-1. These effects of D-ribose seemed almost irreversible but could be prevented by addition of 1 mM aminoguanidine or 10 mM N-acetylcysteine, thus suggesting that glycation and reactive oxygen species, generated through the glycation reaction, serve as mediators of the phenomena. These observations suggest that protein glycation in pancreatic beta cells, which occurs in vivo under chronic hyperglycemia, suppresses insulin gene transcription and thus can explain part of the beta cell glucose toxicity.

Involvement of the homeodomain-containing transcription factor PDX-1 in islet amyloid polypeptide gene transcription

The AT-rich cis-motif A elements of the insulin gene promoter contribute to directing the gene's expression to pancreatic beta-cells, bound by a homeodomain-containing transcription factor, PDX-1/IPF1/STF-1/IDX-1. The islet amyloid polypeptide (IAPP; amylin) gene, which is also expressed in limited tissues such as pancreatic beta- and delta-cells, contained similar AT-rich sequences in its regulatory sequences. To understand the molecular basis of IAPP gene regulation, we evaluated the possible physiological significance of the motif in human IAPP gene regulation. All of the three typical A element-like sequences that matched the CT-box consensus (AT-1, -207/-202; AT-2, -154/-142; and AT-3, -88/-83) were shown to bind specifically to a nuclear factor in the beta-cell-derived MIN6 cells, which was subsequently identified immunologically as the insulin gene transcription factor PDX-1. When the promoter activity was examined in MIN6 cells, the disruption of AT-1 or AT-3 but not of AT-2 caused a marked reduction in the IAPP gene promoter. Thus, despite the observation that all the three A element-like regions could bind to PDX-1, the AT-2 site may not be involved in mediating the PDX-1 action in vivo. These observations suggest the involvement of PDX-1 in human IAPP gene regulation, which seems to be mediated through at least two A element-like cis-motifs in the gene promoter.

Reducing sugars trigger oxidative modification and apoptosis in pancreatic beta-cells by provoking oxidative stress through the glycation reaction

Several reducing sugars brought about apoptosis in isolated rat pancreatic islet cells and in the pancreatic beta-cell-derived cell line HIT. This apoptosis was characterized biochemically by inter-nucleosomal DNA cleavage and morphologically by nuclear shrinkage, chromatin condensation and apoptotic body formation. N-Acetyl-L-cysteine, an antioxidant, and aminoguanidine, an inhibitor of the glycation reaction, inhibited this apoptosis. We also showed directly that proteins in beta-cells were actually glycated by using an antibody which can specifically recognize proteins glycated by fructose, but not by glucose. Furthermore, fluorescence-activated cell sorting analysis using dichlorofluorescein diacetate showed that reducing sugars increased intracellular peroxide levels prior to the induction of apoptosis. Levels of carbonyl, an index of oxidative modification, and of malondialdehyde, a lipid peroxidation product, were also increased. Taken together, these results suggest that reducing sugars trigger oxidative modification and apoptosis in pancreatic beta-cells by provoking oxidative stress mainly through the glycation reaction, which may explain the deterioration of beta-cells under conditions of diabetes.

PDX-1 induces insulin and glucokinase gene expressions in alphaTC1 clone 6 cells in the presence of betacellulin

The pancreatic beta- and alpha-cells are developmentally related to each other but reveal diverse gene expression patterns. Among the two important transcription factors for insulin gene expression, IEF1 is present both in alpha- and beta-cells, but PDX-1/IPF1/STF-1/IDX-1, a homeodomain-containing transcription factor, is present in beta-cells but not in alpha-cells. To elucidate the function of PDX-1 in the expression of beta-cell-specific genes, we established stable alphaTC1 clone 6 (alphaTC1.6)-derived transfectants expressing PDX-1 and examined the changes in the gene expression patterns in them. The exogenous expression of PDX-1 in alphaTC1.6 cells alone could induce islet amyloid polypeptide (IAPP) mRNA expression in the cells but not the expression of insulin, glucokinase, or GLUT2 gene. However, when betacellulin was added to the medium, the PDX-1-expressing alphaTC1.6 cells, but not the control alphaTC1.6 cells, came to express insulin and glucokinase mRNAs. This did not occur with other growth factors such as epidermal growth factor, transforming growth factor alpha, and insulin-like growth factor I. GLUT2 mRNA remained undetectable in the PDX-1--expressing alphaTC1.6 cells. These observations demonstrate the potency of PDX-1 for the expression of the insulin, glucokinase, and IAPP genes and suggest that certain regulatory factors, which can partially be modified by betacellulin, also contribute to the beta-cell specificity of gene expression.