Excitatory synaptic currents in lumbosacral parasympathetic preganglionic neurons evoked by stimulation of the dorsal commissure

Excitatory pathways from the dorsal commissure (DCM) to L(6)-S(1) parasympathetic preganglionic neurons (PGN) were examined using whole-cell patch-clamp recording techniques in spinal cord slices from neonatal rats. PGN were identified by retrograde axonal transport of a fluorescent dye injected into the intraperitoneal space. Excitatory postsynaptic currents (EPSCs) were evoked in PGN by stimulation of DCM in the presence of bicuculline methiodide (10 microM) and strychnine (1 microM) to block inhibitory pathways. Electrical stimulation of DCM evoked two types of inward currents. In the majority of PGN (n = 66), currents (mean amplitude, 47.9 +/- 4.7 pA) occurred at a short and relatively constant latency (3.8 +/- 0.1 ms) and presumably represent monosynaptic EPSCs (Type 1). However, in other neurons (n = 20), a different type of EPSC (Type 2) was noted, consisting of a fast monosynaptic component followed by a prolonged inward current with superimposed fast transients presumably representing excitatory inputs mediated by polysynaptic pathways. Type 1 EPSCs were pharmacologically dissected into two components. A fast component was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 5 microM) and a slowly decaying component was blocked by 2-amino-5-phosphonovalerate (APV, 50 microM). The fast component of Type 1 EPSCs had a linear current-voltage relationship and reversed at a membrane potential of -7.6 +/- 1.3 mV (n = 5). The fast component of Type 2 EPSCs was also blocked by 5 microM CNQX and the remaining slower component was blocked by 50 microM APV. When the DCM was stimulated in the presence of 50 microM APV, the time to peak and decay time constant in Type 1 EPSCs were 1.9 +/- 0.2 and 4.1 +/- 0.8 ms, respectively. Examination of the NMDA receptor-mediated component of the EPSCs in the presence of 5 microM CNQX revealed a current-voltage relationship that had a region of negative slope conductance (from -20 to -80 mV), which was abolished in Mg(2+)-free external solution. The time to peak and decay time constant of this component were 14.2 +/- 2.0 and 91.0 +/- 12.4 ms, respectively. Type 1 EPSCs in some PGN responded in an all-or-none manner and presumably represented unitary synaptic responses; whereas Type 2 EPSCs always exhibited a graded stimulus intensity-response relationship. Paired-pulse facilitation (50-ms interstimulus intervals; 141 +/- 5.6% increase, n = 8) of EPSCs was observed. These results indicate that PGN receive monosynaptic and polysynaptic glutamatergic excitatory inputs from neurons and/or axonal pathways in the DCM.

Hybrid cyst: case reports and review of 15 cases in Japan

Hybrid cyst is a rare cystic lesion that includes more than two components of the pilosebaceous units. To clarify the clinical and pathological features of hybrid cysts, we report two cases and review 15 cases of hybrid cyst in Japan. On the whole, the age range was 12-73 years with a 2.95:1 female predominance and predilection for the scalp and face (46.7%). Most of the tumours presented as a solitary lesion and the size range was 2-45 mm. The most frequent histological type was the combination of infundibular and trichilemmal cysts (60.0%). Studying the clinicopathological features of hybrid cysts helps us in understanding the pathogenesis of diseases arising from pilosebaceous units.

Effect of prostaglandins on parasympathetic neurons in the rat lumbosacral spinal cord

Prostaglandin E(2)(PGE(2)) elicits a variety of effects by activating four subtypes of receptors, EP1, EP2, EP3 and EP4. We examined receptor subtypes mediating the effects of PGE(2) on parasympathetic preganglionic neurons that regulate the activity of pelvic visceral organs. In tonic parasympathetic preganglionic neurons in neonatal rat spinal slices, PGE(2) increased the firing frequency to depolarizing current pulses, induced after-discharges and inhibited spike after-hyperpolarization. PGE(2) did not affect phasic preganglionic neurons. An EP1 agonist inhibited after-hyperpolarizations and induced after-discharges, whereas EP4 agonist reduced after-hyperpolarization and increased evoked firing but did not induce after-discharges. EP2 and EP3 agonists were inactive. These results indicate that PGE(2) acting via EP1 and/or EP4 receptors modulates the excitability and/or excitatory synaptic input to tonic parasympathetic preganglionic neurons.

Relationship between the curvature constant parameter of the power-duration curve and muscle cross-sectional area of the thigh for cycle ergometry in humans

For high-intensity cycle ergometer exercise, the relationship between power output ( P) and its tolerable duration ( t) has been well characterized by the hyperbolic relationship: ( P- theta;(F)). t=W', where theta;(F) has been termed the "critical power" or "fatigue threshold". The curvature constant (W') reflects a constant amount of work which can be performed above theta;(F), and it may be regarded as a muscle energy store. The relationship of this energy store to muscle mass is not known. Therefore, the purpose of this study was to determine the relationships among W', accumulated peak oxygen deficit (accumulated peak O(2)-deficit), and muscle cross-sectional area (CSA) of the thigh for high-intensity cycle ergometry in humans. A group of 17 healthy male subjects (aged 21-41 years) participated in this study. The theta;(F) and W' of the P- t hyperbolic relationship and the accumulated peak O(2)-deficit was calculated by standard procedures. The CSA of muscle, fat and bone in the right thigh were measured using ultrasonography. The mean (SD) of theta;(F), W', accumulated peak O(2)-deficit, and muscle CSA of the thigh were 200.0 (17.8) W, 12.60 (2.94) kJ, 2.29 (0.41) l, and 185.3 (22.6) cm(2), respectively. The muscle CSA of the thigh was positively correlated with W' ( r=0.59, P<0.01) and with accumulated peak O(2)-deficit ( r=0.54, P<0.05). The relationship between W' and accumulated peak O(2)-deficit also showed a positive correlation ( r=0.63, P<0.005). Our results indicated that W' derived from the P- t hyperbolic curve as anaerobic working capacity is related to the CSA of muscle.

Implications from and for food cultures for cardiovascular diseases: Japanese food, particularly Okinawan diets

Okinawans, who have a different ethnicity and food cultural history to other Japanese nationals, and an exceptional longevity have been studied at home and as migrant groups in Hawaii and Brazil. Biomarkers for fish and soy intake and intervention studies indicate that these foods, along with seaweed and green vegetables are candidates for chronic non-communicable disease prevention.

Effects of ischaemia on subsequent exercise-induced oxygen uptake kinetics in healthy adult humans

Leg muscles were occluded (33 kPa) prior to exercise to determine whether the induced metabolic changes, and reactive hyperaemia upon occlusion release just prior to the exercise, would accelerate the subsequent oxygen consumption (VO2) response. Eight subjects performed double bouts (6 min duration, 6 min rest in-between) of square wave leg cycle ergometry both below and above their lactate threshold (LT). Prior to exercise, large blood pressure cuffs were put around the upper thighs. Occlusion durations were 0 min (control), 5 min and 10 min. Ischaemia was terminated within 5 s prior to exercise onset. Heart rate, VO2, ventilatory rate (V(E)), electromyogram (EMG) and haemoglobin/myoglobin (Hb/Mb) saturation were recorded continuously. Single exponential modelling demonstrated that, compared to control (time constant = 53.9 +/- 13.9 s), ischaemia quickened the VO2 response (P < 0.05) for the first bout of exercise above LT (time constant = 48.3 +/- 14.5 s) but not to any other exercise bout below or above LT. The 3-6 min integrated EMG (iEMG) slope was correlated to the 3-6 min VO2 slope (r = 0.73). Hb/Mb saturation verified the ischaemia but did not show a consistent relation to the VO2 time course. Reactive hyperaemia induced a faster VO2 response for work rates above LT. The effect, while significant, was not large considering the expected favourable metabolic and circulatory changes induced by ischaemia.

Existence of beta-methylnorleucine in recombinant hirudin produced by Escherichia coli

A gene encoding for hirudin, a potent thrombin inhibitor, was expressed in Escherichia coli, which is the most widely used host. When the recombinant hirudin analog, CX-397, was overproduced by E. coli (600 mg l(-1)) in the absence of nutrient amino acids in the culture medium, the presence of two derivatives in the final product was observed with extremely increased retention times on reverse-phase high-performance liquid chromatography. Each derivative was due to methylation of an isoleucine residue at Ile29 or Ile59 in the CX-397. The structure was deducible as beta-methylnorleucine (beta MeNle; (2S,3S)-2-amino-3-methylhexanoic acid). The modification pathway of beta MeNle is not thought to be a post-translational modification of the protein because Ile has no functional group in its side-chain. Additionally, beta MeNle is synthesized by mutants of Serratia marcescens that belong to the same family, Enterobacteriaceae, as E. coli (J. Antibiot. 34 (1981a) 1278). These findings suggest that the lack of nutrient amino acids in the culture medium leads to the synthesis of beta MeNle in E. coli, which is then activated by E. coli isoleucyl-tRNA synthetase and incorporated into the overproduced recombinant protein.

Efficacy of granulocyte colony-stimulating factor in the treatment of acute myelogenous leukaemia: a multicentre randomized study

To investigate the efficacy and safety of granulocyte colony-stimulating factor (G-CSF) in patients with acute myelogenous leukaemia, a multicentre randomized study was performed. From October 1993 to September 1996, 270 patients with newly diagnosed acute myelogenous leukaemia were randomized to G-CSF or control groups after remission induction therapy. The G-CSF group received G-CSF (Filgrastim) from 48 h after the completing chemotherapy until the absolute neutrophil count exceeded 1.5 x 10(9)/l. The control group did not receive G-CSF unless severe infection occurred. There were 245 evaluable patients (120 and 125 in the G-CSF and control groups respectively). The complete remission rate was similar in the G-CSF and control groups (80.8% versus 76.8%), as was the 5-year probability of disease-free survival (34.5% versus 33.6%) and overall survival (42.7% versus 35.6%). Neutrophil recovery was significantly faster in the G-CSF group than in the control group (12 d versus 18 d, P = 0.0001). The median duration of febrile neutropenia was significantly shorter in the G-CSF group than in the control group (3 d versus 4 d, P = 0.0001). In conclusion, prophylactic administration of G-CSF after remission induction therapy for acute myelogenous leukaemia is safe and useful even in patients without infection on completing chemotherapy.

Laser cooling of calcium ions by use of ultraviolet laser diodes: significant induction of electron-shelving transitions

Calcium ions are laser cooled in a Paul trap by use of a grating-stabilized UV laser diode. Unusual quantum jumps or fluctuations in the fluorescence signal are observed without application of any shelving lasers. It has become clear that such phenomena can be ascribed to shelving transitions induced by background 393-nm spontaneous photons emitted from the laser medium. Shelving transitions are suppressed by use of an interference filter, and the ions are successfully cooled to crystallization temperature with sufficient reproducibility.

[Late phase II clinical study of amrubicin hydrochloride, a novel synthetic anthracycline derivative anticancer agent, for malignant lymphoma]

A late phase II clinical trial of amrubicin hydrochloride, a novel synthetic anthracycline derivative anticancer agent, was conducted at 14 institutions nationwide, in patients with non-Hodgkin's lymphoma. In this multi-center collaborative study, doxorubicin hydrochloride was replaced by amrubicin hydrochloride in CHOP therapy, a standard regimen for non-Hodgkin's lymphoma consisting of cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate and prednisolone. A total of 39 patients were enrolled in this study between January 1996 and March 1998. Among them, 37 patients were eligible for this study. The study drugs were administered to patients with non-Hodgkin's lymphoma according to the following schedule: amrubicin hydrochloride (100 mg/m2, body surface area), cyclophosphamide (750 mg/m2) and vincristine sulfate (1.4 mg/m2, a maximal dose of 2.0 mg/body) were administered intravenously on day one, while prednisolone (60 mg/m2/day) was administered orally on days 1 to 5. This cycle of treatment was repeated every three weeks in principle. The efficacy and safety were assessed for 37 eligible patients. The combined rate for CR + CRu was 70.3% (26/37) and the overall response rate (CR + CRu + PR) was 86.5% (32/37). demonstrating that amrubicin hydrochloride was very effective in the treatment of non-Hodgkin's lymphoma. The most frequent adverse reactions that occurred during the study were myelosuppressions: leukopenia and neutropenia, 100% (37/37); and decreases in hemoglobin levels, 81.1% (30/37). Thrombocytopenia, elevations of serum GOT and GPT levels, anorexia, nausea/vomitting, fever, stomatitis and alopecia were also observed. Although leukopenia and neutropenia of grade 3 or higher were noted in 89.2% (33/37) and 94.6% (35/37), respectively, they were controllable by administrations of G-CSF or solely by follow-up observations. One patient developed intestinal paralysis (grade 4) and another developed hematemesis. In conclusion, these results indicate that amrubicin hydrochloride is an effective agent as a component of combination chemotherapy for non-Hodgkin's lymphoma.

Excitatory synaptic currents in lumbosacral parasympathetic preganglionic neurons elicited from the lateral funiculus

Excitatory postsynaptic currents (EPSCs) in parasympathetic preganglionic neurons (PGNs) were examined using the whole cell patch-clamp recording technique in L6 and S1 spinal cord slices from neonatal rats (6-16 days old). PGNs were identified by labeling with retrograde axonal transport of a fluorescent dye (Fast Blue) injected into the intraperitoneal space 3-7 days before the experiment. Synaptic responses were evoked in PGNs by field stimulation of the lateral funiculus (LF) in the presence of bicuculline methiodide (10 microM) and strychnine (1 microM). In approximately 40% of the cells (total, 100), single-shock electrical stimulation of the LF elicited short, relatively constant latency [3.0 +/- 0.1 (SE) ms] fast EPSCs consistent with a monosynaptic pathway. The remainder of the cells did not respond to stimulation. At low intensities of stimulation, the EPSCs often occurred in an all-or-none manner, indicating that they were mediated by a single axonal input. Most cells (n = 33) exhibited only fast EPSCs (type 1), but some cells (n = 8) had fast EPSCs with longer, more variable latency polysynaptic EPSCs superimposed on a slow inward current (type 2). Type 1 fast synaptic EPSCs were pharmacologically dissected into two components: a transient component that was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 5 microM), a non-NMDA glutamatergic antagonist, and a slow decaying component that was blocked by 2-amino-5-phosphonovalerate (APV, 50 microM), a NMDA antagonist. Type 2 polysynaptic currents were reduced by 5 microM CNQX and completely blocked by combined application of 5 microM CNQX and 50 microM APV. The fast monosynaptic component of type 1 EPSCs had a linear current-voltage relationship and reversed at a membrane potential of 5.0 +/- 5.9 mV (n = 5), whereas the slow component exhibited a negative slope conductance at holding potentials greater than -20 mV. The type 1, fast synaptic EPSCs had a time to peak of 1.4 +/- 0.1 ms and exhibited a biexponential decay (time constants, 5.7 +/- 0.6 and 38.8 +/- 4.0 ms). In the majority of PGNs (n = 11 of 15 cells), EPSCs evoked by electrical stimulation of LF exhibited paired-pulse inhibition (range; 25-33% depression) at interstimulus intervals ranging from 50 to 120 ms. These results indicate that PGNs receive monosynaptic and polysynaptic glutamatergic excitatory inputs from axons in the lateral funiculus.

Identification of base substitutions in ten types of rare variants of phosphoglucomutase-1 (PGM1) encountered in Japanese

In a previous starch-gel electrophoresis study of erythrocyte phosphoglucomutase-1 (PGM1) in 23,095 Japanese from Hiroshima and Nagasaki, we detected 14 types of rare variant alleles. To determine sequence differences in these rare alleles, cell lines were established from peripheral B-lymphocytes from 24 unrelated individuals in whom nine types of rare variants are presumed to exist on the basis of earlier electrophoresis studies. cDNAs reverse transcribed from mRNAs extracted from these cell lines were amplified by polymerase chain reaction and sequences determined. Amino acid substitution types were deduced from each cDNA sequence. Although two individuals were reported to have an identical electromorph (PGM1 4HR3), sequence analysis revealed that alleles encoding these electromorphs possessed different base substitutions, and one was renamed PGM1 4HR4. As the amino acid substitution of ten different variants could be deduced by cDNA sequence in this study, the effect of each amino acid substitution on enzyme activity could be precisely simulated. The secondary structure of each variant predicted by computer simulations revealed that very decreased activity observed on PGM1 4HR2 protein was caused by significant secondary structure change introduced by the amino acid substitution. On the basis of the crystal structure, the amino acid substitutions of the ten types of rare variants seem to be outside the active center of this enzyme.

Dehydroepiandrosterone (DHEA) stimulates glucose uptake in rat adipocytes: activation of phospholipase D

We examined the effect of dehydroepiandrosterone (DHEA) on glucose uptake and phospholipase D (PLD) activation in rat adipocytes. DHEA (1 microM) provoked a twofold increase in [3H]2-deoxyglucose (DG) uptake for 30 min. Incorporation of [3H]glycerol into diacylglycerol was increased 150% above basal level for 20 min after stimulation with 1 microM DHEA. DHEA increased PLD activity, measured by the incorporation into [3H]phosphatidylethanol in [3H]palmitate labelled rat adipocytes, or by [3H]choline release in [methyl-(3)H]choline labeled rat adipocytes. Our results suggest that DHEA stimulates glucose uptake with activation of PLD in rat adipocytes.

Involvement of c-Src in carcinoma cell motility and metastasis

Carcinoma cells exhibit dysfunction / dysregulation of cell adhesion systems that correlates with their abilities to migrate, invade, and metastasize. Here we show that the tyrosine kinase c-Src is required for motility and metastasis of two carcinoma cell lines. Adherent KYN-2 cells having a high level of c-Src kinase activity become scattered, extend lamellipodia, and exhibit high motility. Expression of a dominant-negative mutant form of c-Src caused formation of stress fibers and focal adhesions, and markedly reduced motility. HCT15 cells extended lamellipodia and became scattered in response to lysophosphatidic acid stimulation in parallel with transient activation of c-Src, which was inhibited by expression of a dominant-negative mutant form of c-Src or treatment with a specific Src kinase inhibitor. Furthermore, implantation of dominant-negative c-Src transfectants into the peritoneal cavity of SCID mice resulted in reduced peritoneal dissemination compared with control transfectants. These findings indicate that c-Src activation is critically involved in carcinoma cell migration and metastasis.

Increased platelet aggregation in diabetic patients with microangiopathy despite good glycemic control

The pathogenesis of diabetic micro- and macroangiopathy cannot be fully explained by hyperglycemia alone. To clarify diabetic complications mediated by increased platelet activity, we have studied platelet aggregation and its second messenger molecules such as protein kinase C (PKC), RhoA, and phosphatidylinositol 3-kinase (PI3- kinase), in six diabetic patients with diabetic retinopathy and other diabetic complications in spite of good glycemic control. Their HbA(1c) levels throughout the observation period had been less than 6% with diet treatment alone, despite which diabetic retinopathy developed to the pre-proliferative stage during 2-8 years observation. Low-dose thrombin (< 0.5 U/ml)-stimulated platelet aggregation in the diabetic patients was enormously elevated compared with healthy control subjects. PKC, RhoA and PI3-kinase activities in the cytosol- and membrane-associated fractions were examined in the platelets from the two patients (Cases 2 and 4). Platelet membrane-associated RhoA and PI3-kinase activity in Case 2 were increased before the stimulation. Platelet RhoA and PI 3-kinase activities in Case 4 were increased after the stimulation with low-dose thrombin (0.01 U/ml). Membrane-associated immunoreactive PKC alpha, but not PKC beta in Cases 2 and 4 was elevated. Although platelet hyperactivity in these four patients was observed, PKC and RhoA in mononuclear leukocytes from these patients were not different from healthy subjects. Membrane-associated PKC alpha and RhoA immunoreactivities also increased in the other three cases. These results suggest that hyperreactivity of PKC alpha may lead to increased RhoA and PI3-kinase activities and platelet hyperfunction in diabetic patients with good glycemic control, and that raised platelet PKC alpha may be implicated in the pathogenesis of diabetic complications.

Distribution of twenty-four hour urinary taurine excretion and association with ischemic heart disease mortality in 24 populations of 16 countries: results from the WHO-CARDIAC study

There is considerable interest in the association between taurine (2-aminoethanesufonic acid) and risk of ischemic heart disease (IHD), but little information has been made available on the distribution of taurine in populations around the world. The present study aimed to describe the differences in taurine excretion levels and their associations with IHD mortality rates in 24 populations in 16 countries worldwide. This was a multicenter cross-sectional study. In each center, 100 men and 100 women aged 48-56 years were selected randomly from the local populations. Twenty-four hour urinary taurine excretion was measured using an amino acid analyzer (Hitachi 835, Ibaragi, Japan). Age-adjusted IHD mortality rates in the relevant populations were calculated using the direct standard method. The results indicated that (a) percentiles 25%, 50% and 75% of the distributions of 24-h taurine excretion showed large variations in the study populations. Median values of taurine ranged from 191.6 micromol/day (St John, Canada) to 2,180.6 micromol/day (Beppu, Japan) in males, and from 127.5 micromol/day (Moscow, Russia) to 1,590.0 micromol/day (Beppu, Japan) in females. The highest overall median value of taurine was found in the Japanese population samples, followed by the Chinese samples (Shanghai and Taiwan). European, North American and oceanic Caucasians, however, had much lower median values of taurine, except in the cases of the samples from France and Spain. (b) Median values of taurine were significantly associated negatively with age-adjusted IHD mortality rates across the 24 study population samples in men (R2=0.42, p<0.01), and in women (R2=0.55, p<0.01). These negative associations remained significant after adjustment for serum total cholesterol, body mass index and urinary sodium to potassium ratios. In conclusion, the study provides, for the first time, a cross-sectional database on distribution of 24-h urinary taurine excretion in 24 population samples worldwide. A strong and inverse association between population levels of taurine excretion and IHD mortality was observed.

Mobilization of transposons by a mutation abolishing full DNA methylation in Arabidopsis

A major component of the large genomes of higher plants and vertebrates comprises transposable elements and their derivatives, which potentially reduce the stability of the genome. It has been proposed that methylation of cytosine residues may suppress transposition, but experimental evidence for this has been limited. Reduced methylation of repeat sequences results from mutations in the Arabidopsis gene DDM1 (decrease in DNA methylation), which encodes a protein similar to the chromatin-remodelling factor SWI2/SNF2 (ref. 7). In the ddm1-induced hypomethylation background, silent repeat sequences are often reactivated transcriptionally, but no transposition of endogenous elements has been observed. A striking feature of the ddm1 mutation is that it induces developmental abnormalities by causing heritable changes in other loci. Here we report that one of the ddm1-induced abnormalities is caused by insertion of CAC1, an endogenous CACTA family transposon. This class of Arabidopsis elements transposes and increases in copy number at high frequencies specifically in the ddm1 hypomethylation background. Thus the DDM1 gene not only epigenetically ensures proper gene expression, but also stabilizes transposon behaviour, possibly through chromatin remodelling or DNA methylation.

Platelet protein kinase C isoform content in type 2 diabetes complicated with retinopathy and nephropathy

It has been reported that platelet aggregation in diabetic patients with microangiopathy is increased compared with healthy subjects. Chronic hyperglycemia is known to cause an increase in diacylglycerol level in various tissues. We examine whether protein kinase C (PKC) isoform content in platelets from diabetic patients is increased compared with healthy subjects, as previously described in the retina, aorta, and heart of diabetic rats. Platelet PKCalpha, beta and zeta immunoreactivity in cytosol, membrane and cytoskeleton (CS) fractions were analyzed by immunoblotting in 20 type 2 diabetic patients (who had been treated with diet alone, sulphonylureas or insulin, and whose condition was complicated with retinopathy, nephropathy, neuropathy and/or macroangiopathy) and in five healthy subjects. PKCalpha, beta and zeta immunoreactivity in cytosol, membrane and CS fractions in platelets from diabetic subjects were not significantly higher than those from healthy subjects. However, platelet PKCbeta immunoreactivity in cytosol fraction was significantly higher in diabetic patients with normal serum creatinine (Cr) level than in diabetic patients with abnormal Cr level (Cr > or =1.5 mg/dl) or in healthy subjects. Moreover, significant negative correlation between PKCbeta immunoreactivity in cytosol fraction of platelets and serum Cr level was found in diabetic patients (P < 0.05). To clarify the effect of treatment for diabetes, PKC isoform immunoreactivity in platelets was measured in type 2 diabetic patients treated with diet alone, sulphonylurea or insulin treatment. Serum creatinine level in diabetic patients with insulin treatment was significantly higher than in diabetic patients with sulphonylurea treatment and diet alone. In addition, PKCbeta immunoreactivity in diabetic patients with insulin treatment was significantly suppressed compared with that in patients treated by sulphonylurea treatment. These results suggest that chronic hyperglycemia may activate platelet PKCbeta isoform, and that insulin treatment may decrease platelet PKCbeta activity. Finally, not only PKCbeta antagonists, but also glycemic control by insulin may prevent development of diabetic microangiopathy.

Oligoclonal expansion of CD4(+)CD28(-) T lymphocytes in recipients of allogeneic hematopoietic cell grafts and identification of the same T cell clones within both CD4(+)CD28(+) and CD4(+)CD28(-) T cell subsets

Recipients of allogeneic bone marrow grafts have clonally expanded CD8(+)CD28(-) T lymphocytes during the early period after transplantation, which leads to skewing of T cell receptor (TCR) repertoires. Here, we have addressed the question of whether clonal expansion of CD28(-) T cells is also observed in CD4(+) T lymphocytes after human allogeneic hematopoietic cell transplantation. We found that the fraction of T cells lacking CD28 expression in the CD4(+) subset was increased after transplantation, and expanded CD4(+)CD28(-) T lymphocytes carrying certain TCRBV subfamilies showed limited TCR diversity. In order to further study the ontogeny of CD4(+)CD28(-) T cells, we analyzed the complementarity-determining region 3 (CDR3) of the TCR-beta chain of CD4(+)CD28(+) and CD4(+)CD28(-) cells. We identified the same T cell clones within both CD4(+)CD28(-) and CD4(+)CD28(+) T cell subsets. These results suggest that both subsets are phenotypic variants of the same T cell lineage.