Modulation of immune response with cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin-induced anergic T cells in chronic idiopathic thrombocytopenic purpura

BACKGROUND

Platelet glycoprotein (GP)-reactive CD4+ T cells are essential for the stimulation and maintenance of antiplatelet autoantibody production in chronic idiopathic thrombocytopenic purpura (ITP). Blocking costimulatory signals could result in platelet-specific T-cell anergy.

METHODS

GP-specific CD4+ T cells from patients with ITP were made anergic using cytotoxic T-lymphocyte-associated antigen 4 immunoglobulin (CTLA4-Ig). The CTLA4-Ig-induced GP-specific anergic T cells were investigated for their inhibitory function on GP-reactive T-cell proliferation and antibody production with in vitro culture systems. To further analyze their tolerizing mechanisms, we cocultured GP-anergic T cells with dendritic cells (DCs) from patients with ITP.

RESULTS

Our studies demonstrated that the anergized GP-specific T cells have profound effects on both GP-specific T-cell proliferation and antibody production. These anergic T cells exerted their suppressive effects mainly in a cell contact-dependent manner, and they were not constitutively suppressive but required specific antigen stimulation to make DCs tolerogenic. The anergic T-cell-modulated DCs could induce the autoreactive T cells to be tolerant, and this effect was not restricted to T cells of the same specificity.

CONCLUSION

Our studies demonstrate the efficacy of CTLA4-Ig in suppressing the pathologic autoimmune responses in ITP. These findings provide new insights into the underlying mechanisms of anergy induction in chronic ITP.

Density-driven segregation in vertically vibrated binary granular mixtures

Segregation in vertically vibrated binary granular mixtures with the same size is studied experimentally. The partially segregated state occurring in this system is observed carefully. We find that the characteristic of the partially segregated state is that the lighter particles tend to rise and form a pure layer on the top of the system while the heavier particles and some of the lighter ones stay at the bottom and form a mixed layer. The ratio of the thickness of the pure top layer to that of the whole system can be taken as an order parameter, which describes the degree of the segregation quantitatively and is useful in the investigation of the system. By use of it, we find that the segregation state is only dependent on the density ratio of the two kinds of particles. The dependent of the segregation on the vibration frequency is also studied by use of this order parameter, and finally, two typical phase diagrams are given.

Myosin light chain kinase regulates synaptic plasticity and fear learning in the lateral amygdala

Learning and memory depend on signaling molecules that affect synaptic efficacy. The cytoskeleton has been implicated in regulating synaptic transmission but its role in learning and memory is poorly understood. Fear learning depends on plasticity in the lateral nucleus of the amygdala. We therefore examined whether the cytoskeletal-regulatory protein, myosin light chain kinase, might contribute to fear learning in the rat lateral amygdala. Microinjection of ML-7, a specific inhibitor of myosin light chain kinase, into the lateral nucleus of the amygdala before fear conditioning, but not immediately afterward, enhanced both short-term memory and long-term memory, suggesting that myosin light chain kinase is involved specifically in memory acquisition rather than in posttraining consolidation of memory. Myosin light chain kinase inhibitor had no effect on memory retrieval. Furthermore, ML-7 had no effect on behavior when the training stimuli were presented in a non-associative manner. Anatomical studies showed that myosin light chain kinase is present in cells throughout lateral nucleus of the amygdala and is localized to dendritic shafts and spines that are postsynaptic to the projections from the auditory thalamus to lateral nucleus of the amygdala, a pathway specifically implicated in fear learning. Inhibition of myosin light chain kinase enhanced long-term potentiation, a physiological model of learning, in the auditory thalamic pathway to the lateral nucleus of the amygdala. When ML-7 was applied without associative tetanic stimulation it had no effect on synaptic responses in lateral nucleus of the amygdala. Thus, myosin light chain kinase activity in lateral nucleus of the amygdala appears to normally suppress synaptic plasticity in the circuits underlying fear learning, suggesting that myosin light chain kinase may help prevent the acquisition of irrelevant fears. Impairment of this mechanism could contribute to pathological fear learning.

Aclarubicin and low-dose Cytosine arabinoside in combination with granulocyte colony-stimulating factor in treating acute myeloid leukemia patients with relapsed or refractory disease and myelodysplastic syndrome: a multicenter study of 112 Chinese patients

One hundred twelve patients with geriatric acute myeloid leukemia (AML), refractory or relapsed AML, or myelodysplastic syndrome and refractory anemia with excess of blasts in transformation (MDS-RAEBt) were entered into this study to receive CAG (aclarubicin and low-dose cytosine arabinoside [Ara-C]in combination with granulocyte colony-stimulating factor [G-CSF]) with the objective of evaluating the efficacy and tolerance of this regimen. Low-dose Ara-C was given subcutaneously at a dosage of 10 mg/m2 every 12 hours on days 1 to 14. Aclarubicin was administered intravenously at a dosage of 14 mg/m2 per day on days 1 to 4 (CAG regimen A) or 7 mg/m2 on days 1 to 8 (CAG regimen B). Recombinant G-CSF was given subcutaneously at a dosage of 200 3g/m2 per day on days 1 to 14. We demonstrated comparable overall complete remission rates for the 4 groups of patients: 30.8% (8/26) in the elderly patients, 48.4% (30/62) in the refractory AML patients, 44.4% (8/18) in the relapsed AML patients, and 38.5% (5/13) in the MDS-RAEBt patients. Of the 52 patients followed up, the 12-month progression-free survival (PFS) and overall survival (OS) rates estimated by the Kaplan-Meier method were 40.73% 3 8.15% and 42.85% 3 8.23%, respectively. The median PFS and OS times were 9.0 3 2.2 months and 11.0 3 1.6 months, respectively. Toxic effects were very rare and mainly consisted of neutropenia and thrombocytopenia due to myelosuppression; approximately 70% to 80% of patients had neutropenia or thrombocytopenia that exceeded National Cancer Institute grade II. Nonhematologic toxicities were not observed in this study. The CAG regimen seems promising, with acceptable toxicity, for the treatment of various categories of poor-prognosis AML and MDS-RAEBt.

Dynamics of a projectile penetrating in granular systems

The impact of a sphere with velocity u0 on a fine, loose granular system under the acceleration due to gravity has been studied by fast video photography. The behavior of the granular bed is found to be similar to a fluid during initial impact, followed by a cavity drag during projectile penetration. From the trajectory of the projectile it is found that the drag on the projectile can be well described by adding a bulk frictional force f to the hydrostatic force kappa(z) where kappa is a constant and z denotes the penetration depth. Both kappa and f are u0 dependent. This form of the drag force suggests that fluidlike viscous dissipations in the bed can be neglected in these three-dimensional (3D) experiments. However, due to the imposed boundary this hydrodynamic term of the drag force is found to be not negligible in quasi-2D granular beds.

Expression of survivin and bax/bcl-2 in peroxisome proliferator activated receptor-gamma ligands induces apoptosis on human myeloid leukemia cells in vitro

The present study was undertaken to investigate the mechanisms of peroxisome proliferator activated receptor-gamma (PPAR-gamma) ligand-induced apoptosis on human myeloid leukemia K562 and HL-60 cell lines. The results revealed that both 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2) and troglitazone (TGZ) have significant anti-proliferation- and apoptosis-inducing effects on these two kinds of leukemia cells. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly using Wright's and Hoechst 33258 staining. Reverse transcription-PCR and western blot analyses demonstrated that both survivin and bcl-2 expression were downregulated markedly, while bax expression was upregulated concurrently when apoptosis occurred. We therefore conclude that 15d-PGJ2 and TGZ have significant apoptosis effects on K562 and HL-60 cells in vitro, and that upregulation of bax as well as downregulation of survivin and bcl-2 expression may be the important apoptosis-inducing mechanisms. The results suggest that PPAR-gamma ligands may serve as potential therapeutic agents for both acute and chronic myeloid leukemia.

Oridonin-induced apoptosis in leukemia K562 cells and its mechanism

Oridonin, an extract from the Chinese herb Rabdosia rubescens, is currently one of the most important traditional Chinese herbal medicines. Recently oridonin has been reported to have anti- tumor effects in a large variety of malignant diseases. In this study, we investigated the apoptotic inducing effect of oridonin in leukemia K562 cells and its mechanism. Cell growth inhibition was measured using a microculture tetrazolium assay, apoptosis was measured by flow cytometry and electron microscopy as well as by DNA fragmentation analysis. Telomerase activity was measured by TRAP-enzyme- linked immunosorbent assay, and the expression of Bcl-2 and Bax proteins was detected by western blot analysis. The results showed that oridonin could inhibit the proliferation and induce apoptosis on leukemia K562 cells remarkably. Telomerase activity as well as Bcl-2 expression was down- regulated, while Bax expression was up-regulated concurrently, when apoptosis ocurred. We therefore conclude that oridonin demonstrated anti-proliferative and apoptosis-inducing effects on K562 cells in vitro, and that changes in bcl-2 and bax protein levels as well as telomerase activity may play an important role in its mechanism of action.

Lesions in the bed nucleus of the stria terminalis disrupt corticosterone and freezing responses elicited by a contextual but not by a specific cue-conditioned fear stimulus

The bed nucleus of the stria terminalis (BNST) is believed to be a critical relay between the central nucleus of the amygdala (CE) and the paraventricular nucleus of the hypothalamus in the control of hypothalamic-pituitary-adrenal (HPA) responses elicited by conditioned fear stimuli. If correct, lesions of CE or BNST should block expression of HPA responses elicited by either a specific conditioned fear cue or a conditioned context. To test this, rats were subjected to cued (tone) or contextual classical fear conditioning. Two days later, electrolytic or sham lesions were placed in CE or BNST. After 5 days, the rats were tested for both behavioral (freezing) and neuroendocrine (corticosterone) responses to tone or contextual cues. CE lesions attenuated conditioned freezing and corticosterone responses to both tone and context. In contrast, BNST lesions attenuated these responses to contextual but not tone stimuli. These results suggest CE is indeed an essential output of the amygdala for the expression of conditioned fear responses, including HPA responses, regardless of the nature of the conditioned stimulus. However, because lesions of BNST only affected behavioral and endocrine responses to contextual stimuli, the results do not support the notion that BNST is critical for HPA responses elicited by conditioned fear stimuli in general. Instead, the BNST may be essential specifically for contextual conditioned fear responses, including both behavioral and HPA responses, by virtue of its connections with the hippocampus, a structure essential to contextual conditioning. The results are also not consistent with the hypothesis that BNST is only involved in unconditioned aspects of fear and anxiety.

Global nature of dilute-to-dense transition of granular flows in a 2D channel

The dilute-to-dense transition of granular flow of particle size d(0) is studied experimentally in a two-dimensional channel (width D) with confined exit (width d). Our results show that with fixed d and D there is a maximum inflow rate Q(c) above which the flow changes from dilute to dense and the outflow rate <Q(t)> drops abruptly from Q(c) to a dense rate Q(d). A rescaled critical rate q(c) is found to be a function of a scaling variable lambda only: q(c) approximately F(lambda), where lambda identical with d/d(0) d/D-d. This form of lambda suggests that the dilute-to-dense transition is a global property of the flow, unlike the jamming transition which depends only on d/d(0). Furthermore, the transition is found to occur when the area fraction of particles near the exit exceeds a critical value which is close to 0.65+/-0.03.

Effects of air on the segregation of particles in a shaken granular bed

Effects of interstitial air on the motions of a large intruder in a shaken granular bed are studied experimentally as a function of ambient air pressure, particle size of the bed, and the density of the intruder. It is found that the intruder always rises from the granular bed in the absence of air. However, the intruder can acquire both positive and negative buoyancy in the presence of air. Negative buoyancy can be observed only when both the density of the intruder and the particle size of the bed are small enough. This negative buoyancy can be explained by the unusual air pressure distribution found in the bed.

KI-67 AND hTERT expression can aid in the distinction between malignant and benign pheochromocytoma and paraganglioma

The clinical and histopathological distinction between benign and malignant pheochromocytomas and paragangliomas is difficult, and reliable diagnostic markers are lacking. Here we have evaluated the prognostic value of human telomerase reverse transcriptase (hTERT) gene expression detected by reverse transcription PCR (RT-PCR); telomerase activity (TA) measured by TRAP (telomeric repeat amplification protocol) assay; immunohistochemical staining for Ki-67/MIB-1; and the mRNA expression of matrix metalloproteinase (MMP)-2 and EMMPRIN (extracellular matrix metalloproteinase inducer) analyzed by in situ hybridization in 32 primary pheochromocytomas or abdominal paragangliomas. hTERT was expressed in 7/11 malignant tumors (defined as presence of metastasis and/or extensive local invasion) as compared with in 2/21 benign tumors. All of the benign tumors showed <1% proliferative activity, as measured by Ki-67/MIB-1 staining. In all three patients with malignant tumors who developed metastases and/or invasive local recurrence during follow-up, the tumors were positive for either hTERT expression or Ki-67/MIB-1 immunoreactivity. TA was not a significant discriminator between benign and malignant tumors, and the value of EMMPRIN and MMP-2 as predictive markers was limited. In conclusion, the findings imply that the combined use of Ki-67/MIB-1 and hTERT, in addition to histopathology, provides a highly specific tool to identify benign pheochromocytoma and abdominal paraganglioma cases that are not at risk of developing recurrent or metastatic disease.

Neuropeptide expression in the human trigeminal nucleus caudalis and in the cervical spinal cord C1 and C2

In migraine and other primary headaches there is a strong vascular component. Besides the trigeminovascular components some of the associated symptoms point to the involvement of brain stem regions. The central limb of the trigeminal vascular pathway is its projection to the trigeminal nucleus caudalis (TNC) and to the C1-C2 levels of the spinal cord. The aim of the present study was to demonstrate the occurrence of some neurotransmitters in these regions in man. In both the TNC and in the Rexed's laminae I and II of the dorsal horns at the C1 and C2 levels there were numerous substance P immunoreactive fibres. Fibres containing calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating peptide (PACAP) were moderately dense in number. Fibres containing vasoactive intestinal peptide (VIP) or nitric oxide synthase (NOS) were not seen in the TNC or at the C1 and C2 levels of the spinal cord.

Granular flows through vertical pipes controlled by an electric field

The flow of granular nickel particles moving down vertical pipes from a hopper in the presence of a local, horizontal ac electric field is studied experimentally. The flow is initiated by opening the bottom outlet of the pipe after the pipe is fully filled with particles from the hopper. The mass of particles flowing out of the pipe is measured as a function of time by an electronic balance. The time dependence of the steady-state flow rate Q, under each fixed voltage V, is obtained. Depending on the magnitude of V, two types of flow behaviors are observed. For low V (<V(c)=2.0 kV), a downward-moving interface-separating a dense particle region below it from a low-density region above-exists between the hopper and the electrodes. Two prominent peaks exist in the Q(t) curve for V in the range of 1.4 kV< or =V<V(c), resulting in two clearly defined flow rates Q(A2) and, later in time, Q(B). The particles measured by Q(A2) originate from the pipe above the electrodes, and those by Q(B) coming initially from the hopper. For high V (> or =V(c)), no interface exists and the whole region between the hopper and the electrodes are densely filled; only one constant flow rate Q(A2) is observed. (The precise meaning of Q(A2) and Q(B) are defined in the text.) The steady-state flow rates Q(A2) and Q(B) measured for each V, are plotted as a function of V. The flow rate Q(A2) is a monotonically decreasing function of V, which can be approximately fitted by a power law, with an exponent of -0.8, while Q(B) is found to be voltage independent. These features result from a competition between the blocking effect of the electric-field region and the gravity-driven pushing effect from the hopper outlet. The local electric field is able to retard the downward movement of a dense column existing above it, but is ineffective in doing so when the column above is dilute in density.

5-HT(1B) and 5-HT(1D) receptors in the human trigeminal ganglion: co-localization with calcitonin gene-related peptide, substance P and nitric oxide synthase

5-Hydroxytryptamine (5-HT) is implicated in migraine and agonist directed against 5-HT(1B) and 5-HT(1D) receptors are commonly used as effective therapies. The antimigraine mechanisms involve the inhibition of intracranial sensory neuropeptide release. In order to determine which 5-HT(1) receptor subtypes are involved we have by immunocytochemistry examined the distribution of 5-HT(1B) and 5-HT(1D) receptors in the human trigeminal ganglia, and addressed which of them colocalize with calcitonin gene-related peptide (CGRP), substance P (SP) or nitric oxide synthase (NOS). We detected that 5-HT(1D) receptor immunoreactivity (i.r.) was predominantly expressed in medium-sized cells (86% of positive cells, 30-60 microm). About 9% of the 5-HT(1D) receptor i.r. cells were large in size (> 60 microm) and 5% were small in size (< 30 microm). In a similar pattern, 5-HT(1B) receptor i.r. was mainly expressed in medium-sized cells (81% in 30-60 microm, 15% in > 60 microm and 4% in < 30 microm). Double immunostaining was used to determine whether the 5-HT(1B) or 5-HT(1D) receptor immunoreactive cells co-localized with either CGRP, SP or NOS. Thus, 89% of the CGRP i.r. cells expressed 5-HT(1D) receptor i.r. and 65% of the CGRP positive cells were 5-HT(1B) receptor positive. Most of the 5-HT(1D) (95%) and the 5-HT(1B) (94%) receptor i.r. cells showed SP immunostaining and 83% of 5-HT(1D) receptor and 86% of 5-HT(1B) receptor i.r. cells contained NOS. In conclusion, both 5-HT(1B) and 5-HT(1D) receptors are expressed in the human trigeminal ganglion and they are mainly localized in medium-sized cells and they seem to colocalize with CGRP, SP and NOS.

[The diagnostic value of platelet glycoprotein-specific autoantibody detection in autoimmune thrombocytopenic purpura]

OBJECTIVE

To evaluate the clinical significance of platelet glycoprotein-specific autoantibody detection and platelet-associated IgG (PAIgG) measurement in the differential diagnosis between autoimmune thrombocytopenia and nonimmune thrombocytopenias.

METHODS

Anti- GP II b/III a and anti-GP I b/IX autoantibodies were detected by a modified monoclonal antibody immobilization of platelet antigens assay (modified MAIPA), and PAIgG by competitive ELISA.

RESULTS

Comparing with the measurement of PAIgG, the GP-specific autoantibody assay was less sensitive but much more specific for the diagnosis of autoimmune thrombocytopenia.

CONCLUSION

The platelet GP-specific autoantibody detection is considerably better than PAIgG measurement in discriminating immune from nonimmune thrombocytopenia.

[A clinical study on the combination of gemcitabine and cisplatin in the treatment of advanced non-small cell lung cancer]

BACKGROUND

To evaluate the efficacy and toxicity of the combination of gemcitabine and cisplatin in the treatment of patients with advanced non-small cell lung cancer (NSCLC).

METHODS

Forty-three patients with locally advanced (stage IIIB) or metastatic (stage IV) NSCLC were enrolled into the study. The patients received gemcitabine 1 000 mg/m² on day 1,8 and 15, and cisplatin 30 mg/m² on day 1-3 of the 28-day cycle; or gemcitabine 1 200 mg/m² on day 1 and 8, cisplatin 30 mg/m² on day 1-3, administered in 21-day cycle.

RESULTS

An objective response was obtained in 48.8% of patients (one complete and 20 partial responses), whereas 13 patients had stable disease and 9 patients were progressive. The response rate was 62.5% in patients with no prior chemotherapy, and the response rate of 31.6% was achieved in patients who had been given prior treatment. Significant difference existed between the two groups (P<0.05). The main toxicities were leukopenia and thrombocytopenia.

CONCLUSIONS

The combination of gemcitabine and cisplatin is a feasible, well-tolerated, and active scheme in the treatment of advanced NSCLC.

[Clinical study on the using methods of cisplatin in lung cancer chemotherapy]

BACKGROUND

To compare the therapeutic effectiveness and toxicity between 1-day perfusion and 3-day perfusion of high-dose cisplatin combined chemotherapy for lung cancer.

METHODS

Sixty-four cases of pathologically proved lung cancer were randomized into groups A and B. Group A (32 cases) received cisplatin at d1, and group B (32 cases) received cisplatin at d1-3. Total dosages of cisplatin were same for both groups (100 mg/m²).

RESULTS

Delayed vomiting in group B (40.63%) was significantly lower than that of group A (53.13%) (P<0.05); the early nephrotoxicity rate of group B(25.00%) was lower than that of group A (46.88%), but there was no statistically significant difference between two groups (P>0.05). The therapeutical response was 62.50% in group A, and 68.75% in group B. No significant difference of the chemotherapeutical response was observed between the two groups (P>0.05).

CONCLUSIONS

In the combined chemotherapy of lung cancer, the division administration of high-dose cisplatin can not only guarantee the therapeutic response, but also abate the gastrotoxicity and the nephrotoxicity of cisplatin.

Telomerase activity in relation to pro- and anti-apoptotic protein expression in high grade non-Hodgkin's lymphomas

BACKGROUND AND OBJECTIVES

Telomerase activity (TA) is determined by the catalytic unit telomerase reverse transcriptase (hTERT). In vitro studies show that hTERT is downregulated by wild type p53 and TA is upregulated by BCL-2 expression. The aim of this study was to investigate the relationship of TA and mRNA expression of hTERT, telomerase RNA (hTER) and Tankyrase in 31 samples from patients with high-grade non-Hodgkin's lymphoma (HG-NHL). The results were then related to apoptosis and proliferation and the expression of p53 and BCL-2 family member proteins.

DESIGN AND METHODS

The telomeric repeat amplification protocol (TRAP) assay and reverse transcription-polymerase chain reaction (RT-PCR) were used to quantify TA, and hTERT, hTER and Tankyrase mRNA expression. Proliferation (Ki67), p53, BCL-2, MCL-1, BAX and BAK protein expression were evaluated by immunohistochemistry. Apoptosis was evaluated by TUNEL staining.

RESULTS

TA was detected in 93% of HG-NHL and tended to be higher in p53+ lymphomas. A positive correlation existed between mRNA expression of hTERT, hTER and Tankyrase. hTERT mRNA expression tended to be higher with increasing levels of apoptosis and proliferation, in HG-NHL samples lacking BAX expression and in samples from patients with survival shorter than 3.5 years. hTER mRNA expression was significantly higher in BAX and BAK negative samples.

INTERPRETATION AND CONCLUSIONS

Telomerase is activated or upregulated in the majority of HG-NHL. Enhanced TA combined with deregulation of the factors responsible for cell survival and proliferation may contribute to the development and progression of lymphomas. Observation that high hTERT mRNA expression may be related to shorter survival should prompt further investigation of the clinical significance of TA and its components in HG-NHL.

Switch from Myc/Max to Mad1/Max binding and decrease in histone acetylation at the telomerase reverse transcriptase promoter during differentiation of HL60 cells

Recent evidence suggests that the Myc and Mad1 proteins are implicated in the regulation of the gene encoding the human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase. We have analyzed the in vivo interaction between endogenous c-Myc and Mad1 proteins and the hTERT promoter in HL60 cells with the use of the chromatin immunoprecipitation assay. The E-boxes at the hTERT proximal promoter were occupied in vivo by c-Myc in exponentially proliferating HL60 cells but not in cells induced to differentiate by DMSO. In contrast, Mad1 protein was induced and bound to the hTERT promoter in differentiated HL60 cells. Concomitantly, the acetylation of the histones at the promoter was significantly reduced. These data suggest that the reciprocal E-box occupancy by c-Myc and Mad1 is responsible for activation and repression of the hTERT gene in proliferating and differentiated HL60 cells, respectively. Furthermore, the histone deacetylase inhibitor trichostatin A inhibited deacetylation of histones at the hTERT promoter and attenuated the repression of hTERT transcription during HL60 cell differentiation. In addition, trichostatin A treatment activated hTERT transcription in resting human lymphocytes and fibroblasts. Taken together, these results indicate that acetylation/deacetylation of histones is operative in the regulation of hTERT expression.

Real-time quantitative telomeric repeat amplification protocol assay for the detection of telomerase activity

BACKGROUND

Telomerase is a ribonucleoprotein enzyme associated with immortalization and transformation of human cells. The telomeric repeat amplification protocol (TRAP) is widely used for the detection of telomerase activity. The TRAP method, although highly sensitive and specific because it includes PCR amplification, is laborious and does not provide precise quantitative information.

METHODS

We developed a real-time quantitative TRAP (RTQ-TRAP) system by combining a real-time PCR technique with the conventional TRAP method. Telomerase activity in human tumor cell lines and in 13 lymphoma samples was measured using the RTQ-TRAP assay, and the results obtained from the samples using the RTQ-TRAP method were compared with the conventional TRAP method.

RESULTS

The RTQ-TRAP method was both accurate and reproducible in measuring telomerase activity in a dilution series of protein extracts from HL60 cells. Telomerase activity in 13 lymphoma samples, as determined by the RTQ-TRAP method, was ninefold lower than that measured by the conventional TRAP method. The half-life of telomerase activity in human tumor cells, as determined using RTQ-TRAP, was much shorter than the half-life reported previously.

CONCLUSIONS

Our results suggest that the conventional TRAP assay frequently overestimates telomerase activity in tumor samples. The RTQ-TRAP method is thus a useful tool to rapidly and precisely quantify telomerase activity.

Intratesticular transplantation of testicular cells from leukemic rats causes transmission of leukemia

A rat T-cell leukemia model was used to study the safety of germ cell transplantation as a mean of preventing infertility in males undergoing gonadotoxic cancer treatment. Donor germ cells were harvested from the testes of terminally ill leukemic rats and were either used directly or cryopreserved and thawed before transplantation by rete testis microinjection. All rats transplanted with testicular cells from leukemic donors developed signs of terminal rat T-cell leukemia, whereas control animals remained healthy. Cryopreservation of the donor germ cells caused a 3- to 6-day delay in the terminal phase of leukemia. When a known number of leukemic cells were mixed with germ cells and microinjected into the testis, the rate of appearance of terminal leukemia was directly related to the number of transferred leukemic lymphoblasts. As few as 20 leukemic cells were able to cause a cancer relapse resulting in terminal leukemia 21 days after transplantation in three of five transplanted animals. Our results demonstrate that germ cell transplantation with the presently used techniques is not safe enough for clinical use. Improved methods for purging testicular specimens of cancer cells or totally new approaches with transient xenogenetic host models to detect contamination of malignant cells must be developed before this technique can be offered to patients without fear of disease relapse.

Frequent amplification of the telomerase reverse transcriptase gene in human tumors

Activation of telomerase is a crucial step during cellular immortalization and malignant transformation of human cells and requires the induction of the catalytic component, human telomerase reverse transcriptase (hTERT), encoded by the hTERT gene. It is poorly understood how the hTERT gene is activated in human cancer cells. In the present study, we examined the hTERT gene copy number in human cancer cell lines and in primary tumor tissues. Amplification of the hTERT gene was observed in 8 of 26 (31%) tumor cell lines and 17 of 58 (30%) primary tumors examined (8 of 21 lung tumors, 3 of 10 cervical tumors, 5 of 19 breast carcinomas, and 1 of 8 neuroblastomas). In addition, 13 of 26 (50%) cell lines and 13 of 58 (22%) primary tumors displayed gain of hTERT gene copies with 3-4 copies/cell. The present findings imply that the hTERT locus may be a frequent target for amplification during tumorigenesis and that this genetic event probably contributes to the dysregulation of telomerase activity occurring in human tumors.

A simple intraductal aspiration method for cytodiagnosis in nipple discharge

OBJECTIVE

To increase cytodiagnostic accuracy for women with spontaneous nipple discharge using a simple intraductal aspiration method.

STUDY DESIGN

We compared the cytodiagnostic accuracy of the conventional squeezing collection method and intraductal aspiration by intravenous catheter in a total of 146 women with spontaneous nipple discharge in a single duct without a mass; they had been pathologically identified at Kaohsiung Medical University Hospital.

RESULTS

Adequate specimens were collected in 96.6% (141/146 cases) of the sample by the intraductal aspiration method as compared to 76.0% collected by the conventional squeezing method (P < .05). An adequate specimen should consist, at a minimum, of six cohesive clusters of well-preserved epithelial cells, with each cluster composed of at least five cells other than foam cells. The cytologic diagnosis was divided into five categories: positive in 9 cases, suspicious in 10, negative with atypical findings in 59, negative in 33 and inadequate specimens in 35 cases that employed the squeezing method. These results were less satisfactory than with the intraductal aspiration method: the smears were positive in 17 cases, suspicious in 14, negative with atypical findings in 78, negative in 32 and inadequate specimens in 5. Our results showed a sensitivity of 92.3% and specificity of 93.9% for the intraductal aspiration method as compared to a sensitivity of 52.9% and specificity of 89.3% for the squeezing method. Among the 27 cancers in this series, correct cytodiagnosis, including suspicious cases, was made in 24 cases by intraductal aspiration, with an accuracy of 88.9%, as compared to the 33.3% (9/27) accuracy of the squeezing method (P < 0.5).

CONCLUSION

For patients with spontaneous nipple discharge, the intraductal aspiration method provides much more accurate cytodiagnosis than does the conventional squeezing method.

Cytokines induce upregulation of vascular P2Y(2) receptors and increased mitogenic responses to UTP and ATP

P2Y(2) receptors, which mediate contractile and mitogenic effects of extracellular nucleotides in vascular smooth muscle cells (VSMCs), are upregulated in the synthetic phenotype of VSMCs and in the neointima after balloon angioplasty, suggesting a role in the development of atherosclerosis. Because released cytokines in atherosclerotic lesions mediate multiple effects on gene transcription in VSMCs, we speculated that cytokines could be involved in the regulation of P2Y(2) receptor expression. Using a competitive reverse transcription-polymerase chain reaction, we detected that interleukin (IL)-1beta induced a time- and dose-dependent upregulation of P2Y(2) receptor mRNA, which was dramatically enhanced when combined with interferon-gamma or tumor necrosis factor-alpha. Lipopolysaccharide also significantly increased the expression of P2Y(2) receptor mRNA. The upregulation of P2Y(2) receptor mRNA was paralleled at the functional level because IL-1beta significantly increased the UTP-stimulated DNA synthesis and the release of intracellular Ca(2+). Actinomycin D completely blocked the upregulation of P2Y(2) receptor mRNA expression by IL-1beta, indicating de novo mRNA synthesis. There was no cAMP accumulation in the cells stimulated with IL-1beta. The cyclooxygenase inhibitor indomethacin and the protein kinase C inhibitor RO-31-8220 inhibited IL-1beta-induced upregulation of P2Y(2) receptor mRNA expression, whereas rapamycin and PD098059 had no effects. Furthermore, neither P38 mitogen-activated protein kinase inhibitor SB20358 alone nor its combination with PD098059 blocked the effect of IL-1beta on the expression of P2Y(2) receptor mRNA. Our results demonstrate that inflammatory mediators upregulate vascular P2Y(2) receptors at the transcriptional and at the functional level through protein kinase C and cyclooxygenase but not cAMP, extracellular signal-regulated kinases 1 and 2, or P38-dependent pathways. This may result in increased growth-stimulatory or contractile effects of extracellular UTP and ATP, which may be of importance in the development of vascular disease.

Stage-specific inhibition of deoxyribonucleic acid synthesis and induction of apoptosis by antracyclines in cultured rat spermatogenic cells

A rapid in vitro method has been developed to detect early effects of cytostatic drugs on rat spermatogenesis. The induction of programmed cell death (apoptosis) and changes in DNA synthesis induced by doxorubicin and idarubicin were measured in specific stages of the cycle of seminiferous epithelium including mitotic (stage V) and meiotic (stage VIII-IX) S-phase cells. The model was used to investigate the protective effect of an organic thiophosphate, amifostine, against the toxicity of antracyclines. Premitotic DNA synthesis was found to be more sensitive than premeiotic DNA synthesis to antracyclines. Idarubicin was more toxic than doxorubicin to germ cells in inducing apoptosis and suppressing DNA synthesis. Amifostine had no protective effect against doxorubicin- or idarubicin-induced inhibition of DNA synthesis. In contrast, a significant stimulation of DNA synthesis in premitotic cells by amifostine was found, suggesting that this compound may have a stimulative effect on spermatogenic stem cells. These data show that stage-specific dissection of the seminiferous tubules and their in vitro exposure to predetermined doses of drugs may give us a unique possibility to detect drug action and protection against the cytotoxicity of antineoplastic agents at the cellular level of the spermatogenic cycle.

[A multicenter randomized phase II trial of domestic product of rhG-CSF(Rui Xue Xin) in preventing leukopenia caused by chemotherapy in patients with lung cancer]

BACKGROUND

To evaluate the effect and toxicity of the domestic product of rhG-CSF (Rui Xue Xin) in preventing leukopenia caused by chemotherapy in patients with lung cancer.

METHODS

67 patients in multicenter were randomly devided into AB group and BA group. The first cycle was a trial cycle (chemotherapy plus injection of Rui Xue Xin) , and the second cycle was a control cycle (chemotherapy alone) in AB group. On the contrast , the first cycle was a control cycle , and the second cycle was a trial cycle in BA group. The changes of white blood cell (WBC) and absolute neutrophil counts (ANC) , and the side effect of Rui Xue Xin were observed and compared between the trial cycle and control cycle.

RESULTS

Of the 67 patients , 6 cases were out of the trial because of patient compliance , and the another one case due to fever , and the other 61 cases could be used to analyze and to evaluate the effects and toxicity of Rui Xue Xin. The duration of leukopenia and neutropenia in cycle A was significantly shorter than that in cycle B ( P < 0. 01) . The nadirs of WBC and ANC following chemotherapy were remarkably higher in cycle A than those in cycle B ( P < 0. 01) . The incidence of chemotherapy delay due to WBC < 4. 0 *109 /L on the 21st day after chemotherapy in cycle A was also significantly lower than that in cycle B ( P < 0. 01) . The total rate of side effects of Rui Xue Xin was 26. 2 % , including pain and scleroma on the injection sites , weakness , fever. But , all of them were mild and didn't need to give any treatment.

CONCLUSIONS

The results demonstrate that Rui Xue Xin is able to reduce the degree of leukopenia and neutropenia , and to shorten the duration of leukopenia and neutropenia caused by chemotherapy in patients with lung cancer. The toxicity is also slight.

Characterization of contractile P2 receptors in human coronary arteries by use of the stable pyrimidines uridine 5'-O-thiodiphosphate and uridine 5'-O-3-thiotriphosphate

The present study was designed to evaluate the relative contribution of the different contractile P2 receptors in endothelium-denuded human coronary arteries by use of extracellular nucleotides, including the stable pyrimidines uridine 5'-O-3-thiotriphosphate (UTPgammaS) and uridine 5'-O-thiodiphosphate (UDPbetaS). The isometric tension of isolated vessel segments was recorded in vitro, and P2 receptor mRNA expression was examined by reverse transcription-polymerase chain reaction. alphabeta-Methylene-adenosine triphosphate (alphabeta-MeATP) elicited contractions at a low concentration (pEC(50) = 5.2), indicating the presence of contractile P2X receptors. The P2Y responses were analyzed after P2X receptor desensitization with 10 microM alphabeta-MeATP. The stable nucleotides UTPgammaS and adenosine 5'-O-3-thiotriphosphate (ATPgammaS), which are agonists of P2Y(2) or P2Y(4) receptors, were approximately 2 log units more potent than the endogenous UTP and ATP (pEC(50) = 4.6 and 3.8 for UTPgammaS and ATPgammaS). The efficacy of these responses were approximately double that of the P2X agonist alphabeta-MeATP (E(max) = 125% for UTPgammaS, 126% for ATPgammaS, and 68% for alphabeta-MeATP), suggesting a primary role for contractile P2Y(2/4) receptors. The P2Y(2) receptor agonist diadenosine tetraphosphate also stimulated contraction, whereas the selective P2Y(1) agonist adenosine 5'-O-thiodiphosphate and the selective P2Y(6) agonist UDPbetaS had no effect. Reverse transcription-polymerase chain reaction analysis of mRNA from endothelium-denuded human coronary arteries demonstrated strong bands for P2Y(2) and P2X(1), although bands for P2Y(1), P2Y(4), and P2Y(6) receptor mRNA could also be detected. In conclusion, the stable pyrimidines UDPbetaS and UTPgammaS are important tools for P2 receptor subtype characterization in intact tissues with ectonucleotidase activity. Extracellular nucleotides elicit contraction of human coronary arteries primarily by activation of P2Y(2) and P2X receptors, whereas a role for P2Y(1) and P2Y(6) receptors can be excluded. Antagonists of P2Y(2) and P2X receptors may be useful in the treatment of coronary vasospastic disorders.

Angiotensin II type 1 receptors stimulate protein synthesis in human cardiac fibroblasts via a Ca2+-sensitive PKC-dependent tyrosine kinase pathway

The aim of the present study was to investigate the proliferative effects of Ang II in human cardiac fibroblasts. The effects of Ang II in human cardiac fibroblasts on the 3H-thymidine incorporation, the cell number, the 3H-leucine incorporation and the total protein content were measured. The expression of receptor mRNA was performed by reverse transcription-polymerase chain reaction (RT-PCR). Ang II increased 3H-leucine incorporation in a concentration-dependent manner but not 3H-thymidine incorporation in primary cultures of human cardiac fibroblasts. The maximum effect (24 +/- 3% over control) was obtained at a concentration of 10 nM. There were no significant alterations of cell number or total protein content, suggesting that Ang II stimulated protein synthesis but did not induce hypertrophy. The accumulation of 3H-leucine was blocked by the AT1 receptor antagonist candesartan but not by the AT2 receptor antagonist PD123319. By using RT-PCR, both AT1 and AT2 receptors mRNA were found to be expressed in human cardiac fibroblasts. The selective MAPKK inhibitor PD098059, the protein kinase C inhibitor K252a or the phospholipase C inhibitor U73122 did not significantly inhibit Ang II augmented 3H-leucine incorporation. However, this was significantly blocked by the Ca2+-dependent protein kinase C inhibitor GO6976, the non-selective protein kinase inhibitor staurosporine and the tyrosine kinase inhibitor tyrphostin 25. The effects of Ang II were unaffected by the Gi-protein blocker pertussis toxin, indicating a Gi-protein-independent pathway. Ang II was synergistic with insulin but showed no significant increase on 3H-leucine incorporation when combined with PDGF or EGF. In summary, Ang II stimulates protein synthesis through AT1 receptors in human cardiac fibroblasts, but has no hypertrophic or hyperplastic effect. The response is mediated by a MAPKK-independent and Ca2+-sensitive PKC-dependent pathway.

[Comparison between carboplatin and cisplatin plus etoposide and carboplatin plus etoposide in the treatment of small cell lung cancer.]

BACKGROUND

To evaluate the effect and toxicity of combination chemotherapy with carboplatin and cisplatin plus etoposide (CPE regimen) and carboplatin plus etoposide (CE regimen) in the treatment of small cell lung cancer (SCLC) .

METHODS

Thirty-two patients with SCLC were treated with CPE and CE regimens , and each regimen had 16 cases respectively. There were 10 retreated cases in CPE group and 7 retreated cases in CE group.

RESULTS

The total response rate (CR + PR) was 81. 3 %(13/ 16) in CPE group , and 87. 5 %(14/ 16) in CE group ( P > 0. 05) respectively. The response rate of the retreated cases in CPE group was 60 %(6/ 10) , and 42. 9 %(3/ 7) in CE group ( P < 0. 05) . The bone marrow suppression rate was 71. 9 % in CPE group and 93. 8 % in CE group ( P < 0. 05) . There were no significant differences between other toxicity in both groups ( P > 0. 05) .

CONCLUSIONS

The therapeutic effect of CPE regimen in SCLC is similar to that of CE regimen , but the bone marrow suppression rate of CPE regimen is less severe than that of CE regimen. The therapeutic effect of CPE regimen is better than that of CE regimen for the retreated cases.

DNA methylation and expression of p16(INK4A) gene in pulmonary adenocarcinoma and anthracosis in background lung

The p16 (CDKN2/MTS-1/INK4A) tumor-suppressor gene is frequently inactivated by DNA methylation in lung carcinomas. To clarify whether background anthracosis may play a role in DNA methylation and inactivation of the p16 gene, we examined DNA methylation of the p16-promoter region by methylation-specific polymerase chain reaction, and p16 expression immunohistochemically, and compared the results with the level of background anthracosis which was measured by an original quantitative method. At autopsy, DNA methylation of the p16 gene was observed in 6/19 tumors (32%) from patients who had died of pulmonary adenocarcinoma. The degree of background anthracosis (the effect of extrinsic carcinogenic factors) (mean absorbance value, A = 0.715) of the cases with p16-gene methylation was significantly higher than that without methylation (mean A value = 0.298). p16 expression was inactivated in all tumors with p16-gene methylation. The mean A value of black dust matter deposition in cases with normal expression of p16 (A = 0.151) was significantly lower than cases with abnormal expression of p16 (A = 0.531). These results indicate that the level of background anthracosis is closely associated with inactivation of p16 expression and also DNA methylation of the p16-gene promoter region in pulmonary adenocarcinogenesis. Int. J. Cancer (Pred. Oncol.) 84:609-613, 1999.

[The establishment of a human pancreatic mixed ductal-endocrine carcinoma cell line]

OBJECTIVE

Establishment of a human pancreatic mixed ductal-endocrine carcinoma cell line.

METHODS

A specimen of this type of cancer was obtained from a male patient at the head of pancreas. The tumor tissue was minced into pieces and inoculated subcutaneously in nude mice. With two successive subcutaneous implants, a piece of tumor tissue taken from the 2(nd) implanted neoplasm of a nude mouse was minced into minute tissue masses and inoculated in a media containing 10% fetal bovine serum.

RESULTS

Currently, it has been passed to the 55(th) passage. Cells of this cell line (PC-EN) kept simultaneously the morphologic patterns of a pancreatic ductal and endocrine tumor which were verified by histochemistry and immunohistochemistry assays. Some of the PC-EN cells showed presence of neuroendocrine granules by electron microscopy. The growth rate of this cell line was relatively low. Kakryotype analysis showed two cell populations with its major mode of chromosomes numbers as 48 in one, and 56 in the other. Study on K-ras gene demonstrated that PC-EN harbored a mutated codon 12. Several gastrointestinal hormones and CEA were detected in PC-EN cells and in the supra-cultured medium using radioimmunoassay.

CONCLUSIONS

The cellular and molecular biologic characteristics of PC-EN cells illustrated that this cell line preserved the morphology of a pancreatic ductal and endocrine tumor and possessed a special growth property, chromosome karyotype, and mutation of Ki-ras gene, but also showed a biologic exocrine and endocrine functions of the pancreas. The establishment of PC-EN cell line will provide a useful model in vitro for further investigating the cellular and molecular biology of exocrine and endocrine tumors of the pancreas.

Increase in cardiac P2X1-and P2Y2-receptor mRNA levels in congestive heart failure

We wanted to study the expression of P2-receptors at the mRNA-level in the heart and if it is affected by congestive heart failure (CHF). To quantify the P2 receptor mRNA-expression we used a competitive RT-PCR protocol which is based on an internal RNA standard. The P2 receptor mRNA-expression was quantified in hearts from CHF rats and compared to sham-operated rats. Furthermore, the presence of receptor mRNA was studied in the myocardium from patients with heart failure. In the sham operated rats the G-protein coupled P2Y-receptors were expressed at a higher level than the ligand gated ion-channel receptor (P2X1). Among the P2Y-receptors the P2Y6-receptor was most abundantly expressed (P2Y6 > P2Y1 > P2Y2 = P2Y4 > P2X1). A prominent change was seen for the P2X1- and P2Y2-receptor mRNA levels which were increased 2.7-fold and 4.7-fold respectively in the myocardium from the left ventricle of CHF-rats. In contrast, the P2Y1-, P2Y4- and P2Y6-receptor mRNA levels were not significantly altered in CHF rats. In human myocard the P2X1-, P2Y1-, P2Y2-, P2Y6- and P2Y11-receptors were detected by RT-PCR in both right and left atria and ventricles, while the P2Y4-receptor band was weak or absent. In conclusion, most of the studied P2-receptors were expressed in both rat and human hearts. Furthermore, the P2X1- and P2Y2-receptor mRNA were upregulated in CHF, suggesting a pathophysiological role for these receptors in the development of heart failure.

MAPKK-dependent growth factor-induced upregulation of P2Y2 receptors in vascular smooth muscle cells

The ATP- and UTP-sensitive P2Y2 receptor which mediates both contractile and mitogenic effects has recently been shown to be upregulated in the synthetic phenotype of the vascular smooth muscle cell (VSMC). Using a competitive RT-PCR we demonstrate that the P2Y2 receptor mRNA is increased by fetal calf serum and other growth factors in a MAPKK-dependent way. This was confirmed at the functional level by examining UTP-stimulated release of intracellular Ca2+. Furthermore, the P2Y2 receptor mRNA is positively autoregulated by ATP and the mRNA is rapidly degraded with only 26% remaining after 1 h in the presence of actinomycin D. Our results indicate growth factor regulation and rapid turnover of the P2Y2 receptor mRNA, which may be of importance in atherosclerosis and neointima formation after balloon angioplasty.

[The expression of bombesin receptor in gastric cancer]

OBJECTIVE

To observe the expression of receptor mRNA and its protein in SGC 7901 cells.

METHODS

(1) RT-PCR and Southern blot hybridization were performed for detection of gastrin releasing peptide GRP-R mRNA; (2) Covalent cross-linking study with biotinyl-bombesin and enhanced chemoluminescence (ECL) was performed to identify GRP-R at protein levels in SGC 7901 cells.

RESULTS

(1) It is shown that the molecular weight of the cDNA was consistent with that of expected. Southern blot was then used to further prove that specific GRP-R mRNA was expressed by SGC 7901. (2) GRP-R protein was shown by covalent cross-linking in SGC 7901 and the molecular weight of bombesin/GRP-R in SGC 7901 cells was about 75000.

CONCLUSION

By using RT-PCR, Southern blot and covalent cross-linking techniques, it was demonstrated that SGC 7901 cells can express bombesin receptor mRNA and protein. The results of this study provides a basis for further researches on bombesin intracellular signal transmission pathway and the role of bombesin and bombesin receptor antagonists in oncological research.

[Analysis of the causes of necrosis of retained flap on tibial side after transplantation of the great toe nail flap]

OBJECTIVE

In order to investigate the causes of necrosis of the retained flap after transplantation of the great nail flap, according to the principle of plastic surgery, the following operation was designed.

METHODS

A tongue-shaped great toe flap was made with its base on the tibial side of the great toe and the width of the base was 1 cm to 1.5 cm. The flap contained the supporting vessels and nerves and the periosteum was also preserved.

RESULTS

From June 1982 to November 1997, the flap was used to repair 267 case, 277 fingers defects. After operation, the retained flap on the tibial side developed necrosis in 13 sides, an incidence of 4.69%, and in 78 sides, there was necrosis on the grafted skin on the donor site, an incidence of 28.7%. Most of the wounds healed after changing dressing, while 37 wounds healed from another skin graft. Of these cases, 178 cases had been followed up for 5 months to 16 years. It was found that the retained tibial tongue-shaped flap showed hyperplasia which extended to the weightbearing area of metatarso-phalangeal of great toe. It showed that the taking off of great toe nail flap according to first dorsal metatarsal artery (FDMA) I, II or III type, the incidence of development of necrosis of retained flap on tibial side showed no significant difference (P > 0.05).

CONCLUSION

It was believed that the necrosis of the retained flap was not related to the FDMA classification but had relation with the design, operative technique and presence of infection.

The implication of anthracosis in the development of pulmonary adenocarcinoma

The relationship between anthracosis, which is the deposition of black dust matter in the lung parenchyma, and the development of pulmonary adenocarcinoma has not been fully characterized. In order to clarify whether background black dust matter deposition could be implicated in the development of pulmonary adenocarcinoma, we measured the level of anthracosis at autopsy in 47 patients who had died of pulmonary adenocarcinoma. Both lungs of all 47 cadavers were examined. Twenty-micrometer sections were cut from formalin-fixed, paraffin-embedded blocks of the largest cut surface of each lung. Black dust matter was extracted from the sections and blotted onto a nitrocellulose membrane. The density of the blotted black dust matter was then analyzed using an imaging densitometer. There were no significant differences in the density of black dust matter deposition between lungs affected by pulmonary adenocarcinoma and control lungs. However, well differentiated adenocarcinomas tended to develop more frequently than poorly differentiated ones in lungs showing less deposition. We found a very strong correlation between the degree of black dust matter deposition and smoking history. Patients with severe anthracosis tended to have a poorer prognosis than those with mild anthracosis.

Impact of endogenous thrombopoietin levels on the differential diagnosis of essential thrombocythaemia and reactive thrombocytosis

By using the newly commercialized Quantikine human TPO immunoassay, plasma thrombopoietin (TPO) concentrations were measured in 12 patients with essential thrombocythaemia (ET), 13 patients with reactive thrombocytosis (RT) and 11 healthy volunteers. For the healthy volunteers the mean plasma TPO concentration was 21.1+/-11.0 pg/ml. The mean plasma TPO concentration in the group of RT was slightly lower (16.4+/-8.6 pg/ml) but did not differ significantly from the control group. The mean plasma TPO concentration in ET patients (44.1+/-45.2 pg/ml) was significantly (p<0.05) higher than the mean for RT patients, but did not differ statistically from the mean of healthy volunteers. These data suggest a defective clearance of plasma TPO in patients with ET.

Phenotype changes of the vascular smooth muscle cell regulate P2 receptor expression as measured by quantitative RT-PCR

Studies using selective agonists have suggested that the contractile effect of extracellular nucleotides, such as ATP and UTP, in blood vessels is mediated mainly by P2X1 receptors with a smaller contribution of P2Y receptors while the mitogenic effect is mediated by P2Y (P2Y1, P2Y2, P2Y4, and P2Y6) receptors with no effect of P2X1 receptors. This indicates a difference in P2 receptor expression between the contractile and the synthetic phenotype of the SMC. To measure the expression of mRNA for these receptors a competitive RT-PCR assay was developed that utilised synthetic RNA-competitors allowing determination of the number of mRNA copies for each receptor in the samples. In the synthetic phenotype the mitogenic P2Y1 and P2Y2 receptor transcripts were upregulated by 342- and 8-fold, respectively, while the contractile P2X1 receptor is totally downregulated and the P2Y4 and P2Y6 receptors were unchanged. This plasticity of the receptor expression may be important in the transition from the contractile to the synthetic SMC phenotype.

Immediate results and dilatation effect of the vein-covered Palmaz-Schatz stent assessed by intravascular ultrasound

To evaluate the clinical results of stenting using the vein-covered Palmaz-Schatz (PS) stent by intravascular ultrasound (IVUS). Twenty-eight patients with angina pectoris or confirmed ischemia were entered into this study. Thirteen were allocated to the vein-covered PS stent group and 15 to the normal Palmaz-Schatz stent group. The immediate clinical results in these groups and changes in lumen dimension as assessed by IVUS, were investigated. Acute success was 100% in both groups. There were no immediate complications. Subacute thrombosis occurred in one patient in the vein-covered PS group. In the vein-covered PS group, percent diameter stenosis of the involved coronary artery changed from 70.2% before stenting to 8.8% immediately after and 42.2% at 5 months follow-up. The respective values were 84.5%, 13.4%, and 36.5% in the normal Palmaz-Schatz group. Restenosis in the vein-covered group was 23.1% and in the Palmaz-Schatz group was 20%, showing no significant differences between the two groups. The luminal area in the vein-covered group as assessed by IVUS increased from 3.2 mm2 to 7.4 mm2 (pre to post) and from 3.2 mm2 to 8.2 mm2 in the normal Palmaz-Schatz group. The plaque area decreased from 13.6 mm2 to 10 mm2 (pre to post) in the vein-covered group and from 13.0 mm2 to 9.2 mm2 in the Palmaz-Schatz group. In this study, conducted in a limited number of cases, it is possible to use vein-covered stent like as usual Palmaz-Schatz stent. The vein-covered stent had less dilative effect compared with the Palmaz-Schatz stent. This was probably because of its increased profile but there was no difference in the occurrence of subacute thrombosis or in restenosis rate.

Plasma thrombopoietin levels in thrombocytopenic states: implication for a regulatory role of bone marrow megakaryocytes

To evaluate the diagnostic value of thrombopoietin (TPO, c-mpl ligand) measurements, and clarify the regulatory mechanisms of TPO in normal and in thrombocytopenic conditions, the plasma TPO concentration was determined in normal individuals (n = 20), umbilical cord blood (n = 40), chronic idiopathic thrombocytopenic purpura (ITP; n = 16), in severe aplastic anaemia (SAA; n = 3), chemotherapy-induced bone marrow hypoplasia (n = 10), myelodysplastic syndrome (MDS; n = 11), and sequentially during peripheral blood progenitor cell transplantation (n = 7). A commercially available ELISA and EDTA-plasma samples were used for the analysis. The plasma TPO concentration in the normals and umbilical cord blood were 52 +/- 12 pg/ml and 66 +/- 12 pg/ml, respectively. The corresponding values in patients with SAA and chemotherapy-induced bone marrow hypoplasia were 1514 +/- 336 pg/ml and 1950 +/- 1684 pg/ml, respectively, and the TPO concentration, measured sequentially after myeloablative chemotherapy and peripheral blood progenitor cell transplantation, was inversely related to the platelet count. In contrast, the plasma TPO recorded in patients with ITP (64 +/- 20 pg/ml) and MDS (68 +/- 23 pg/ml) were only slightly higher than normal levels. In conclusion, TPO levels were significantly elevated in patients in which bone marrow megakaryocytes and platelets in circulation were markedly reduced, whereas TPO levels were normal in ITP patients, and only slightly increased in the MDS patients. These latter patients displayed a preserved number of megakaryocytes in bone marrow biopsies. Our data support the suggestion that megakaryocyte mass affects the plasma TPO concentration. In thrombocytopenic patients a substantially increased plasma TPO implies deficient megakaryocyte numbers. However, TPO measurements do not distinguish between ITP and thrombocytopenia due to dysmegakaryopoiesis, as seen in MDS patients.

Platelet proteins as autoantibody targets in idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP), caused by autoantibodies directed against certain platelet antigens, is the most common entity of the immune thrombocytopenias. ITP is an acquired disorder and can affect both children and adults. However, the clinical syndromes of ITP are distinct between children and adults. Childhood (acute) ITP characteristically is acute in onset, occurs within 1-2 weeks of an infection, usually of viral origin, resolves spontaneously within 6 months. Adult (chronic) ITP has an insidious onset and rarely resolves spontaneously. Over the last decade considerable new information has accumulated as to the pathophysiological mechanisms of immune thrombocytopenias. In addition, most of the knowledge on this disorder has been obtained from studies of adult patients with chronic ITP. The present work gives an updated overview of the platelet autoantigens and the molecular immunological reactions in ITP.

Induction of immune tolerance in adult rabbits undergoing heterotopic cardiac transplantation

OBJECTIVE

To induce experimental immune tolerance in rabbits and observe its effects on heterotopic cardiac transplantation.

METHODS

Donor's splenic lymphocytes pretreated with platinum metal chelator were injected into the recipient's mesenteric-portal vein. Cyclosporin A was perfused through the donor's heart.

RESULTS

The injection of donor's splenic lymphocytes before transplantation could significantly prolong the survival time of the heterotopically transplanted heart. The effect of two injections was better than that of one. Radioactive tracer studies showed that the 99mTc-HMPAO tagged lymphocytes injected into the recipient rabbit were later concentrated in the liver, though initially they were distributed in multiple organs. The induced immune tolerance was antigen-specific, and it neither affect the other immune functions of the lymphatic system prominently nor exert any harmful effect on the recipient's liver and renal functions. The perfusion of cyclosporin A through the donor heart could block the glycosyl groups, such as D-glucose, D-mannose or N-acetyl-galactosamine on the surface of the myocardial cells, thus might change the antigenic expression, effectively preventing rejection of the graft by the host, and might be considered as a new method to block graft rejection in cardiac transplantation. The combined use of the above-mentioned two methods acted on both the host and the donor, thus reducing the exposed antigens on the donor organ as well as the immune reaction against the donor antigens, and resulting in synergistic effect in inducing immune tolerance in adult rabbits, and resulting in relatively long-term survival of transplanted hearts.

CONCLUSION

This report may provide the experimental basis for inducing immune tolerance in clinical transplantation.

Adjustable forming of thermoplastic composites for orthopaedic applications

The present study was focused on the development of a special thermoforming technique for manufacturing of continuous fibre reinforced thermoplastic composite parts with complex surface contours. In particular, a stamp forming process was modified to investigate the potential manufacturing advantages of thermoplastic composites in orthopaedic applications. An apparatus was designed which allowed the thermoforming procedure to be fully automatic, i.e. a cold pre-consolidated laminate panel, as the feed material, was heated up in an infrared heating zone and then transferred into a cold mould system, where it was stamp formed. Both halves of the mould were made of many tiny round metal sticks in a metal frame. This needle-bed mould allowed one to copy any contour by pushing it slightly on spring fixed sticks. The desired position of these sticks could then be adjusted by forcing the side plates of the metal frame together. To prevent any press mark of stick-tops on the composite, i.e. to achieve smooth surfaces of the themoformed composite parts, flexible rubber pads were needed to cover the mould surfaces. Experimental results showed that the surface profile of CF/PP and GF/PP composites formed by the needle-bed mould reproduced fairly well the contour of a saddle shaped, complex model sample. Unique properties of this needle-bed mould are that it can be repeatedly used, and that it can copy any complex surface contours, for example a bone surface, by simply adjusting the stick positions according to the special surface requirements.

Biotinylated platelets have an impaired response to agonists as evidenced by in vitro platelet aggregation tests

Biotinylation of platelets, using a water soluble biotin analogue which reacts with primary amines, has been proposed to be a reliable technique for study of in vivo survival of platelets and their subpopulations. The information about the influence of this technique on platelet function has been limited. In the present work we studied the effect of in vitro biotinylation on platelet function and activation. Washed human platelets, at a concentration of 1 x 10(9)/L, were biotinylated with five different concentrations of sulfo-NHS-biotin or NHS-LC-biotin, ranging from 0 to 5 mM. The degree of platelet activation during and after biotinylation was monitored by measuring the externalization of P-selectin, and the platelet function was evaluated by aggregometry. It was observed that biotinylated platelets, in a dose dependent manner, displayed an impaired aggregation response. A slight increase in platelet membrane P-selectin occurred during the labelling procedure.

Multiple quinine-dependent antibodies in a patient with episodic thrombocytopenia, neutropenia, lymphocytopenia, and granulomatous hepatitis

A 58-year-old man experienced episodes of fever, vomiting, and diarrhea over a 2-year period. The laboratory evaluation during these attacks consistently disclosed thrombocytopenia, leukopenia, and elevated liver enzymes. A liver biopsy performed at one of these attacks showed a typical picture of granulomatous hepatitis. In retrospect, all episodes seemed to be associated with the ingestion of quinine. Indeed, such a correlation was established by a challenge with quinine. By using flow cytometry, quinine-dependent IgG antibodies to platelets were detected in the patient serum. By a two-color flow cytometric assay, the patient serum was also found to hold quinine-dependent antibodies specific for neutrophils, T lymphocytes, and B lymphocytes. Moreover, serum absorbed with neutrophils in the presence of quinine continued to react with platelets, T lymphocytes, and B lymphocytes; serum that was absorbed with mononuclear cells continued to react with neutrophils and platelets. These experiments indicated that the antigen targets were different on platelets, neutrophils, and lymphocytes. Further, the patient serum in the presence of quinine immunoprecipitated surface-labeled platelet proteins with electrophoretic mobilities closely resembling those of glycoprotein (GP) Ib/IX and GPIIb/IIIa. By a modified monoclonal antibody-specific immobilization of platelet antigens assay, the patient serum in the presence of quinine reacted with platelet GPIb/IX and GPIIb/IIIa. Also, the patient serum in the presence of quinine immunoprecipitated an uncharacterized 15-kD double-band from surface-labeled granulocyte proteins. We conclude that our patient's thrombocytopenia, neutropenia, and lymphocytopenia were caused by quinine-dependent antibodies and that these antibodies recognized cell lineage-specific epitopes.