Expression of functional human recombinant interleukin-12 and development of a new reliable bioassay by interferon-gamma ELISPOT

Interleukin-12 (IL-12) is one of the important cytokines for promoting the differentiation and maturation of type 1 T helper cells and facilitating the initiation of cell-mediated immune responses. Because of its multi-functional roles in anti-tumor and anti-viral immunity, IL-12 is considered a promising therapeutic cytokine in immunotherapy against cancer and infectious diseases. To evaluate the therapeutic efficacy, an easy and reliable quantitative assay for functional IL-12 is essential. Presently, IL-12 concentration is often determined by ELISA or RIA, which may or may not correlate with IL-12 biological function. Established IL-12 bioassays are based on a time-consuming lymphocyte proliferation assay and require freshly isolated peripheral blood lymphocytes.

Alteration of acidic lipids in human sera during the course of pregnancy: characteristic increase in the concentration of cholesterol sulfate

In this study, we determined the concentrations of acidic lipids, including cholesterol sulfate (CS), sulfatide and GM3 ganglioside, in human sera of non-pregnant state and during the course of pregnancy. In human sera of non-pregnant women, GM3 was present at a concentration of 8 nmol/ml and the concentrations of CS and sulfatides were less than 20% of that of GM3. The concentration of sulfatides in sera at the second trimester of gestation was decreased, but CS gradually increased from the first to the third trimester of gestation with a correlation coefficient of 0.66, and a correlation between the concentration of CS and weeks of gestation (p<0.01). CS was also contained in the placental villi, and its concentration increased from the first to the third trimester of gestation, suggesting that placental CS is one of the source of CS in the blood by shedding.

Cyclic ADP-ribose and the regulation of calcium-induced calcium release in eggs and cardiac myocytes

Cyclic ADP-ribose (cADPR) is a cyclic metabolite of NAD+ synthesised in cells and tissues expressing ADP-ribosyl cyclases. Although it was first discovered in sea-urchin egg extracts as a potent calcium mobilizing agent, subsequent studies have indicated that it may have a widespread action in the activation of calcium-release channels in such diverse systems as mammalian neurones, myocytes, blood cells, eggs, and plant microsomes. In this review we focus on recent work suggesting that cADPR enhances the sensitivity of ryanodine-sensitive calcium-release channels (RyRs) to activation by calcium, a phenomenon termed calcium-induced calcium release (CICR). Two roles for cADPR in calcium signaling are discussed. The first is as a classical second messenger where its levels are controlled by extracellular stimuli, and the second mode of cellular regulation is that the levels of intracellular cADPR may set the sensitivity of RyRs to activation by an influx of calcium in excitable cells. These two possible actions of cADPR are illustrated by considering the signal transduction events during the fertilization of the sea-urchin egg and the modulation of CICR during excitation-coupling in isolated guinea-pig ventricular myocytes, respectively.

Thymic carcinoma (report of 14 cases)

This paper reports of 14 cases of thymic carcinoma. Most of them with symptoms of chest pain, chest stuffy and discomfort, but without combined with extrathoracic syndromes. The tumors always were large in size and frequently invaded adjacent organs, hence with low resection rate. In this series, complete resection of tumor only 2 cases, partial resection in 7 cases, exploratory thoracotomy in 5 cases. Thymic carcinoma was an extremely malignant tumor with extensive invasion intrathoracally and early metastasis extrathoracally. The common sites of metastasis were bone, liver, lung and extrathoracic lymph nodes. Adjuvant therapy postoperatively was given to all patients. Follow-up of 1-8 years showed 10 cases death, of which 5 cases died within the first year after surgery, 3 cases within the second year. Four patients were still alive so far, in which 3 patients were within 1.5 years postoperatively. Pathological studies revealed 9 cases of squamous epithelial cell thymic carcinoma, 3 of lymphoepithelioma-like thymic carcinoma and 2 of small cell undifferentiate thymic carcinoma.

Actions of cADP-ribose and its antagonists on contraction in guinea pig isolated ventricular myocytes. Influence of temperature

Although it is becoming widely accepted that cADP-ribose (cADPR) can regulate calcium release from the endoplasmic reticulum in sea urchin eggs and in a variety of mammalian cell types, it remains controversial whether this substance might influence calcium release during excitation-contraction coupling in cardiac muscle. We have investigated possible actions of cADPR in intact cells isolated from guinea pig ventricle, paying particular attention to the possible influence of temperature. At 36 degrees C, myocyte contraction was influenced by cytosolic application of cADPR in a concentration-dependent manner (showing an approximately 30% increase in contraction with 5 mumol/L cADPR applied via a patch pipette in myocytes stimulated to fire action potentials at 1 Hz). Calcium transients measured with fura 2 were also increased by 5 mumol/L cADPR. Antagonists of cADPR reduced contraction at 36 degrees C (by approximately 35% with either 50 mumol/L 8-Br-cADPR or 5 mumol/L 8-amino-cADPR applied via the patch pipette). At room temperature (approximately 20 degrees C to 24 degrees C), no significant effects on contraction were detected with either cADPR or its antagonists. At 36 degrees C, treatment of the cells with a mixture of 2 mumol/L ryanodine and 1 mumol/L thapsigargin to suppress function of the sarcoplasmic reticulum stores of calcium prevented the action of 5 mumol/L cADPR applied via a patch pipette. These observations are consistent with an action of cytosolic cADPR to enhance calcium-induced calcium release from the sarcoplasmic reticulum in guinea pig ventricular myocytes at 36 degrees C. The observed influence of temperature under the conditions of our experiments is one factor that might help to account for failure to detect actions of cADPR and its analogues in some previous studies.

[Microwave operation of angiofibroma of nasopharynx under nasal endoscope]

Two patients with angiofibroma of nasopharynx were treated with microwave operation under nasal endoscope in our hospital. This operation could reduce the amount of blood less than operations by palatine apporach and nose apporach apprentently. So the blood transplantation was avoid. Meanwhile, it lessen somatopsychic pain and ecnomical burden. Because of the clean and clear operation field under nasal endoscope, the tumor could be removed completely and correctly. Then, the possibility of relapse was reduced.

[VATS in malignant pleural effusions]

Between November 1992 and October 1996, 20 patients with malignant pleural effusions were submitted to VATS under general anesthesia. The overall positive histological diagnoses were obtained through VATS (20/20). The malignant pleural mesothelioma in 8 cases and metastatic cancers in 12 cases were histopathologically confirmed. Talc pleurodesis was performed for all the cases, and 18 patients gained lasting pleurodesis and the other 2 patients did not. The failure of pleurodesis was due to that the lung could not reexpand to come into contact with the chest wall. Postoperative complications included transient fever and slight asthma in 2 cases, and the symptoms were relieved obviously after some simple therapy to symptom. In conclusion, VATS has provided a high positive diagnosis of patients with malignant pleural effusions not diagnosed by conventional methods and good results in pleurodesis, but some operating skills must be emphasized.

[A deep regional impedance method measuring the blood distribution in the lung]

A new deep regional impedance method to measure the blood distribution in the lung has been developed. Using a multi-electrode system, the method simultaneously detects impedance information of chest, and back including lung and the thorax, then extracts the impedance information directly from lung with a special data processing approach in order to eliminate thorax effect on the measurement. The salt pool experiment and the preliminary application of measuring the blood distribution in the lung have been made. The results show that the method raises the relative sensitivity and the distinguishability of the blood measurement in the lung, and as a new deep regional impedance measurement method, it has a good prospects of clinical application in the future.

Loss of protein kinase C inhibition in the beta-T594M variant of the amiloride-sensitive Na+ channel

We previously reported the presence of a novel variant (beta-T594M) of the amiloride-sensitive Na+ channel (ASSC) in which the threonine residue at position 594 in the beta-subunit has been replaced by a methionine residue. Electrophysiological studies of the ASSC on Epstein-Barr virus (EBV)-transformed lymphocytes carrying this variant showed that the 8-(4-chlorophenylthio) adenosine 3':5'-cyclic monophosphate (8cpt-cAMP)-induced responses were enhanced when compared to wild-type EBV-transformed lymphocytes. Furthermore, in wild-type EBV-transformed cells, the 8cpt-cAMP-induced response was totally blocked by the phorbol ester, phorbol 12-myristate 13-acetate (PMA). This inhibitory effect of PMA was blocked by a protein kinase C inhibitor, chelerythrine. We now have identified individuals who are homozygous for this variant, and showed that PMA had no effect on the 8cpt-cAMP-induced responses in the EBV-transformed lymphocytes from such individuals. Cells heterozygous for this variant showed mixed responses to PMA, with the majority of cells partially inhibited by PMA. Our results demonstrate that an alteration in a single amino acid residue in the beta-subunit of the ASSC can lead to a total loss of inhibition to PMA, and establish the beta-subunit as having an important role in conferring a regulatory effect on the ASSC of lymphocytes.

Follow-up study of children with precocious puberty treated with cyproterone acetate. Ad hoc Committee for CPA

A total of 1840 children and adolescents treated with cyproterone acetate (CPA) to block gonadal function, as a treatment for precocious puberty, short stature and other disorders, were registered to survey for the risk of developing hepatic tumors. Patients responding to follow-up numbered 1552 (85%). The cumulative dose and duration of CPA therapy for boys and girls were 110.4g and 2.6 years, and 122.9 g and 2.8 years, respectively. Among the 1552 patients, five hepatoma cases were found. Four underwent successful surgery and remain alive and well to date. Two of the 5 cases had been given more than 500g, the other 3 more than 1000 g, of CPA. Three had also been given androgens before CPA administration. Although further follow-up is necessary to monitor for the development of adenoma and hepatoma, the risk of developing these tumors among patients to whom limited doses of CPA were administered appears to be negligible.

[Insulin receptors in diabetes mellitus]

We described the clinical significance of the measurement of insulin receptors and the mechanism of non-insulin dependent diabetes mellitus (NIDDM). Changes in insulin receptor (IR) of red blood cells in 47 patients with NIDDM were compared with those of 28 normal controls. The levels of high and low-affinity IR in the 47 patients with NIDDM were lower than those of normal controls and were prominent in untreated new NIDDM patients. Hyperinsulinemia was not found in these patients, indicating that the low IR is a primary defect not caused by the "down regulation" mechanism. In the IDDM patients the levels of high and low-affinity IR were higher than those of the normal controls, but decreased markedly after insulin therapy, indicating that the "up regulation" is attributable to the high IR levels, other than the primary IR defect.

[The development and clinical application of an easily carried Chinese electrocardiographic auto-diagnostic apparatus]

The 8090 single chip has been used as main core to complete the automatic process, such as controlling electrocardiographer, collecting information, measuring parameters, analysis, diagnosis, and printing Chinese report.

Activation of endothelial cell phospholipase D by migrating neutrophils

BACKGROUND

Vascular endothelium plays a critical role in regulating the integrity of intercellular adhesive and junctional contacts in response to migrating neutrophils during the inflammatory process. Biochemical responses induced in endothelial cells by adherent, migrating neutrophils are poorly understood. This study was undertaken to explore the possibility that endothelial cell phospholipase D (PLD) is activated when neutrophils migrate through endothelial cell monolayers in response to chemotactic stimuli.

METHODS

Bovine pulmonary artery endothelial cells (BPAEC) were cultured on polycarbonate filters at the base of inserts in Transwell chambers (Costar, Cambridge, MA) and subsequently labeled with 3H-myristic acid. Human neutrophil migration through BPAEC monolayers was measured in response to a chemoattractant gradient produced by leukotriene B4 (LTB4). After neutrophils were induced to migrate through endothelial monolayers in the presence of 0.1% ethanol, the filters were excised, and cellular lipids were extracted. Levels of labeled phosphatidylethanol (PEt), an index of activation of endothelial cell PLD, were measured in chromatographs of resolved phospholipids.

RESULTS

When neutrophils migrated through endothelial monolayers in response to LTB4, endothelial cells accumulated significant levels of PEt, indicating activation of endothelial cell PLD. Kinetic analysis demonstrated that PEt generation closely paralleled chemotactic migration over a 2-hour time period. Direct contact of neutrophils with the endothelium failed to induce PEt formation in the absence of neutrophil chemotaxis, and LTB4 was an ineffective stimulus of endothelial cell PLD activity in the absence of migrating neutrophils. Neutrophil migration-dependent endothelial PLD activation was observed when chemotaxis was induced by an unrelated chemoattractant, serum activated by exposure to Escherichia coli. However, neutrophil migration alone could not account for activation of endothelial cell PLD, since the peptide chemoattractant f-met-leu-phe (FMLP) induced comparable migration of neutrophils through endothelial monolayers but did not induce PEt generation.

CONCLUSIONS

Our study indicates that chemotactic migration of neutrophils through endothelial monolayers results in endothelial cell PLD activation. This process may amplify both target and effector cell reactivity during the inflammatory response.

Ascorbic acid-dependent activation of the osteocalcin promoter in MC3T3-E1 preosteoblasts: requirement for collagen matrix synthesis and the presence of an intact OSE2 sequence

Osteocalcin is a hormonally regulated calcium-binding protein made almost exclusively by osteoblasts. In normal cells, osteocalcin expression requires ascorbic acid (AA), an essential cofactor for osteoblast differentiation both in vivo and in vitro. To determine the mechanism of this regulation, subclones of MC3T3-E1 preosteoblasts were transiently transfected with 1.3 kb of the mouse osteocalcin gene 2 promoter driving expression of firefly luciferase. AA stimulated luciferase activity 20-fold after 4-5 days. This response was stereospecific to L-ascorbic acid and was only detected in MC3T3-E1 subclones showing strong AA induction of the endogenous osteocalcin gene. Similar results were also obtained in MC3T3-E1 cells stably transfected with the osteocalcin promoter. A specific inhibitor of collagen synthesis, 3,4-dehydroproline, blocked AA-dependent induction of promoter activity, indicating that regulation of the osteocalcin gene requires collagen matrix synthesis. Deletion analysis of the mOG2 promoter identified an essential region for AA responsiveness between -147 and -116 bp. This region contains a single copy of the previously described osteoblast-specific element, OSE2. Deletion and mutation of OSE2 in DNA transfection assays established the requirement for this element in the AA response. Furthermore, DNA-binding assays revealed that MC3T3-E1 cells contain OSF2, the nuclear factor binding to OSE2, and that binding of OSF2 to OSE2 is up-regulated by AA treatment. Taken collectively, our results indicate that an intact OSE2 sequence is required for the induction of osteocalcin expression by AA.

Computer-assisted, quantitative cytokine enzyme-linked immunospot analysis of human immune effector cell function

Originally developed for detecting antibody production from B lymphocytes, the enzyme-linked immunospot (ELISPOT) assay was later modified to assess cytokine production from various immune effector cells. Although the ELISPOT assay can detect antibody or cytokine production at the single-cell level, the visual counting of spots in a 96-well plate under a microscope makes this method unsuitable for handling large sample sizes. Here, we introduce a computer-assisted image analysis system to overcome this problem. This system makes the data analysis step of the ELISPOT assay convenient, objective, sensitive and suitable for handling large sample pools. Studies requiring lymphocyte proliferation assay, cytotoxic lymphocyte assay and precursor frequency assay can be conducted through the ELISPOT assay. This is demonstrated here using examples such as mixed lymphocyte allogeneic reactions and human immunodeficiency virus antigen-specific, cell-mediated immune responses.

Xwnt-8 and lithium can act upon either dorsal mesodermal or neurectodermal cells to cause a loss of forebrain in Xenopus embryos

When Xenopus gastrulae are made to misexpress Xwnt-8, or are exposed to lithium ions, they develop with a loss of anterior structures. In the current study, we have characterized the neural defects produced by either Xwnt-8 or lithium and have examined potential cellular mechanisms underlying this anterior truncation. We find that the primary defect in embryos exposed to lithium at successively earlier stages during gastrulation is a progressive rostral to caudal deletion of the forebrain, while hindbrain and spinal regions of the CNS remain intact. Misexpression of Xwnt-8 during gastrulation produces an identical loss of forebrain. Our results demonstrate that lithium and Wnts can act upon either prospective neural ectodermal cells, or upon dorsal mesodermal cells, to cause a loss of anterior pattern. Specifically, ectodermal cells isolated from lithium- or Wnt-exposed embryos are unable to form anterior neural tissue in response to inductive signals from normal dorsal mesoderm. In addition, although dorsal mesodermal cells from lithium- or Wnt-exposed embryos are specified properly, and produce normal levels of the anterior neural inducing molecules noggin and chordin, they show a greatly reduced capacity to induce anterior neural tissue in conjugated ectoderm. Taken together, our results are consistent with a model in which Wnt- or lithium-mediated signals can induce either mesodermal or ectodermal cells to produce a dominant posteriorizing morphogen which respecifies anterior neural tissue as posterior.

Distribution of cholesterol sulfate and its anabolic and catabolic enzymes in various rabbit tissues

Cholesterol sulfate (CS) recently has been shown to be involved in signal transduction pathway. To evaluate its functional significance, we determined the concentration of CS, and the specific activities of cholesterol sulfotransferase and CS sulfatase in various tissues of rabbit, and compared them with the concentration of sulfoglycolipids in rabbit tissues. CS was present in the epithelia and mucosa, but not in the tunica muscularis, of the digestive tract, trachea, uterine endometrium and uterine cervix. It was also present in lung, spleen, kidney, prostate, skin, hair, and nail at relatively high concentrations. Its concentration in the uterine endometrium was nine times higher in pseudopregnant rabbits than in nonpregnant rabbits because of activation of cholesterol sulfotransferase and inhibition of CS sulfatase in the pseudopregnant rabbits. Sulfoglycolipids were not detected in the uterine endometria of either non-pregnant- or pseudopregnant rabbits. However, sulfoglycolipids were detected at relatively high concentrations in the cerebrum, cerebellum, stomach, duodenum, jejunum, testis, and kidney of rabbits and thus the tissues in which both sulfolipids were detected were the gastrointestinal tract and kidney. In the digestive tract, the concentration of CS decreased in the order esophagus, stomach, duodenum, and jejunum, but that of sulfatide increased in the same order, indicating distribution of CS in the squamous epithelium. In addition, both CS and sulfatide were detected in the serum. On the other hand, CS sulfatase activity was detected in all tissues examined, even in hair, from which the enzyme was liberated by brief sonication, and its highest specific activity was detected in the liver. The specific activity of cholesterol sulfotransferase varied among the tissues examined and was found to be significantly high in the esophageal epithelium and the uterine endometrium of pseudopregnant rabbit, indicating involvement of cholesterol sulfation in the formation of epithelium.

Molecular characterization and expression of the Erwinia carotovora hrpNEcc gene, which encodes an elicitor of the hypersensitive reaction

The nucleotide sequence of hrpNEcc DNA, cloned from Erwinia carotovora subsp. carotovora strain Ecc71, reveals a coding region of 1,068 bp which matches the size of hrpNEcc transcripts. hrpNEcc is predicted to encode a glycine-rich protein of approximately 36 kDa. Like the elicitors of the hypersensitive reaction (HR) produced by E. chrysanthemi (HarpinEch) and E. amylovora (HarpinEa), the deduced 36-kDa protein does not possess a typical signal sequence, but it contains a putative membrane-spanning domain. In Escherichia coli strains overexpressing hrpNEcc, the 36-kDa protein has been identified as the hrpNEcc product by Western blot analysis using anti-HarpinEch antibodies. The 36-kDa protein fractionated from E. coli elicits the HR in tobacco leaves. Moreover, a HrpN- and RsmA- double mutant (RsmA = regulator of secondary metabolites) does not produce this 36-kDa protein or elicit the HR, although this strain, like the RsmA- and HrpN+ bacteria, overproduces extracellular enzymes and macerates celery petioles. These observations demonstrate that hrpNEcc encodes the elicitor of the HR, designated HarpinEcc. The levels of hrpNEcc transcripts are affected in both RsmA+ and RsmA- strains by media composition and carbon sources, although the mRNA levels are substantially higher in the RsmA- strains. The expression of hrpNEcc in Ecc71 is cell density dependent and is activated by the quorum-sensing signal, N-(3-oxohexanoyl)-L-homoserine lactone (OHL). By contrast, hrpNEcc expression in an RsmA- strain is independent of cell density, and substantial expression occurs in the absence of OHL. The effects of cultural conditions and the occurrence of putative cis-acting sequences, such as consensus sigma 54 promoters and an hrp promoter upstream of the transcriptional start site, indicate that the production of HarpinEcc in wild-type RsmA+ E. carotovora subsp. carotovora is tightly regulated. These observations, taken along with the finding that the HR is caused by RsmA- mutants but not by RsmA+ strains (Cui et al., 1996, Mol. Plant-Microbe Interact. 9:565-573), strongly support the idea that the inability of the wild-type pectolytic E. carotovora subsp. carotovora to elicit the HR is due to the lack of a significant level of HarpinEcc production.

Phosphatidic acid-mediated regulation of neutrophil plasma membrane CD45-phosphotyrosine phosphatase

CD45-phosphotyrosine phosphatase (PTPase) constitutes the major portion of thr PTPase activity within plasma membranes of neutrophilic leukocytes, where it regulates signals leading to functional activation. We have previously demonstrated that the catalytic component of neutrophil plasma membrane CD45-PTPASE is regulated by a cytosolic inactivator which itself is attenuated upon cellular stimulation, allowing enzyme translocated from granule stores to express full activity. The present study investigated mechanisms of cytosolic inactivator attenuation. Preincubation of plasma membranes of stimulated neutrophils with cytosol from resting cells resulted in a rapid loss of membrane-associated PTPase activity. Phosphatidic acid had no direct effect on plasma membrane PTPase activity but blunted in a dose dependent manner the effects of the PTPase inactivator. Inactivator attenuation was not observed with equivalent concentrations of either diacylglycerol or lysophosphatidic acid. Optimal attenuation of inactivator activity was obtained with long chain, soluble ligands, such as dicapryl phosphatidic acid. Inhibitors of neutrophil plasma membrane ecto-phosphatidic acid phosphohydrolase did not block inactivator attenuation, suggesting that phosphatidic acid and not one of its metabolites was the entity responsible. In conclusion, neutrophil plasma membrane PTPase is dynamically regulated by a cytosolic inactivator, the inhibition of which may potentiate the effects of PTPase translocated during cellular stimulation. Phosphatidic acid generated as a consequence of cellular stimulation may mediate this inhibition and thereby regulate the effects of tyrosine kinases activated during the initial phases of cell stimulation.

[Surface photovoltaic spectroscopic investigation of Bacteriorhodopsin (BR)]

The surface photovoltaic spectra (SPS) of Bacteriorhodopsin-based films were systematically measured. The results show that the BR films are characterized by the specific photovoltaic effect. The SPS response of the BR films depends on the fabrication and humidity of the film. The intermediate M412 and O640 of BR are observed in the SPS of HEPES-containing BR film, indicating that HEPES has very important function to stabilize intermediate M412. The observations are explained in terms of the photocycle of BR and the mechanism of photovoltage generation.

Focal segmental glomerulosclerosis in primates infected with a simian immunodeficiency virus

Focal and segmental glomerulosclerosis (FSG) with endothelial tubuloreticular inclusions (TRIs) is the typical lesion of human HIV-associated glomerulopathy. Autopsy studies showed the presence of FSG in 3 of 15 macaques dying 15-120 weeks after experimental infection with a simian immunodeficiency virus (SIVMne). Ultrastructural studies generally revealed numerous endothelial TRIs (also present in normals), mesangial expansion, and evidence of mesangial cell injury. One additional animal had a small-vessel polyarteritis with a proliferative and focally crescentic glomerulonephritis; seven animals had mild, multifocal interstitial nephritis. All animals had documented viremia after infection; 14 of 15 developed antibodies to SIV postinoculation. Additional postmortem findings included severe enterocolitis, encephalitis, and opportunistic infections. In contrast, autopsy studies of macaques infected with a type D simian retrovirus (SAIDS-D/Washington, SRV-2) for similar periods of time (n = 40) showed no evidence of FSG. One SRV-infected animal had a mild proliferative glomerulonephritis. These studies indicate SIV-infected primates may provide a relevant model for study of human HIV-associated nephropathy. They also indicate the variable pathology that can be seen in primate infections of distinct retrovirus types, each of which produces a simian immunodeficiency state that resembles human AIDS.

Acute myelogenous leukaemia with t(8;21) translocation of normal cell origin in mosaic Down's syndrome with isochromosome 21q

We report a 13-year-old girl with Down's syndrome (DS) having a mosaic karyotype of 46,XX/46,XX, -21,+i(21q), who developed acute myelogenous leukaemia (AML) (FAB M1). The t(8;21) translocation generating a AML1/MTG8 chimaeric gene of her blasts was demonstrated by cytogenetic analysis and reverse transcription-polymerase chain reaction. Interestingly, the leukaemic clone with t(8;21) did not have isochromosome 21q, indicating that the blasts were of normal cell origin. These findings suggest that, in older patients with DS, 21 trisomy cells have no greater predisposition to develop AML than normal karyotypic cells.

Autoradiographic determination of changes in opioid receptor binding in the limbic system of the Columbian ground squirrel at different hibernation states

To localize and quantify the state-dependent changes in various opioid receptor subtypes in the limbic system of non-hibernating and hibernating Columbian ground squirrels, quantitative receptor-binding autoradiography was used. Compared to the non-hibernating animals, the binding density of [3H]-[D-Pen2,5]-enkephalin (DPDPE) to the delta receptor in the lateral septum, CA3, and the hippocampal fissure of the hippocampal formation was significantly decreased in the hibernating ground squirrels. A significant reduction in the binding density of [3H]-[D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin (DAGO) to mu receptor was also observed in the medial septum and the CA3 region of the hippocampus of the hibernating animals. In contrast, a decrease in [3H]ethylketocyclazocine (EKC) binding to the kappa receptor was only observed in the claustrum and CA3 of the hippocampus during hibernation. The differential changes in binding to various opioid receptors suggest that different opioid subtypes may exert different physiological roles in regulating the specific states (entrance, maintenance and arousal) of a hibernation bout.