Vitamin E and the Y4 agonist BA-129 decrease prostate cancer growth and production of vascular endothelial growth factor

BACKGROUND

A biologically active form of vitamin E, alpha-tocopherol succinate (ATS), has been shown to induce apoptosis of hormone-refractory prostate cancer in vitro and inhibit cell growth in vivo. The gastrointestinal hormone peptide YY (PYY) has growth inhibitory activity against multiple cancer cell lines and is synergistic with ATS against breast and pancreatic cancer growth. BA-129, a specific Y4 receptor agonist, has growth inhibitory effects on pancreatic cancer in vitro. We investigated the effects of BA-129 and ATS on prostate cancer growth and evaluated their effects on vascular endothelial growth factor (VEGF) production.

METHODS

A hormone-refractory human prostate cancer cell line, PC-3, was treated with ATS alone at 10 pg/ml, PYY or BA-129 alone at doses of 75 and 500 pmol/ml, or a combination of the two agents. Cell growth was measured by MTT assay and hemocytometry using trypan blue. Quantitative measurement of VEGF was performed by ELISA. Statistical analysis was achieved by ANOVA.

RESULTS

ATS exhibited significant (P < 0.05) growth inhibitory effects in prostate cancer cells. PYY also inhibited growth (P < 0.05). ATS treatment reduced VEGF production (P < 0.05). PYY treatment increased VEGF. When ATS was given in combination with BA-129, VEGF production was further reduced (P < 0.05).

CONCLUSIONS

Both PYY and ATS inhibit growth in hormone-refractory prostate cancer, with augmentation when used in combination. VEGF production is inhibited by vitamin E, but increased by PYY. ATS abolishes the augmented VEGF response to PYY. Our data suggest that PYY is involved in the regulation of VEGF production and prostate cancer growth.

Comparative contribution to dextromethorphan metabolism by cytochrome P450 isoforms in vitro: can dextromethorphan be used as a dual probe for both CTP2D6 and CYP3A activities?

Dextromethorphan (DXM) is a widely used probe drug for human CYP2D6 activity both in vitro and in vivo. In humans, DXM is metabolized to dextrorphan (DXO), as well as 3-methoxymorphinan (MEM) and 3-hydroxymorphinan (HYM). The formation of MEM has been attributed primarily to CYP3A4, and the use of DXM has been debated as a simultaneous probe for CYP3A4 and CYP2D6 activities. Recently, we found that highly purified CYP2D6 has significant DXM N-demethylase activity in addition to its well known DXM O-demethylase activity. Therefore, we desired to further compare the contribution to DXM metabolism by individual human cDNA-expressed cytochromes P450, including 2C8, 2C9, 2C18, 2C19, 2D6, 2B6, and 3A4. Metabolites were quantified following separation by high-pressure liquid chromatography and apparent Michaelis-Menten constants determined for the appearance of DXO and MEM. Intrinsic clearance values were estimated for each P450 and normalized using the average percentage content and relative activity factor approaches for comparison. Simplified kinetic models (when [S] << K(m), V(max)/K(m) = V(o)/[S]) were used at fixed DXM concentrations of 20 (for DXM N-demethylation) and 0.2 microM (for DXM O-demethylation), as well as 2 microM to mimic plasma DXM concentrations in human extensive metabolizers. The results confirm that CYP2D6 contributes at least 80% to the formation of DXO, and CYP3A4 contributes more than 90% to the formation of MEM. All of our in vitro results are consistent and indicate that DXM as a marker for monitoring both CYP2D6 and CYP3A activities is practical in an average human or human liver microsomal preparation.

Characterization of dextromethorphan O- and N-demethylation catalyzed by highly purified recombinant human CYP2D6

The O-demethylation of dextromethorphan to dextrorphan in humans is catalyzed primarily by cytochrome P450 2D6 (CYP2D6). However, contrary to conventional wisdom, preparations of recombinant cytochrome P450 (P450) expressed from CYP2D6*1 cDNA also appear to produce significant amounts of 3-methoxymorphinan, the N-demethylated metabolite of dextromethorphan, when assayed in vitro. We hypothesized that both pathways were intrinsic to 2D6 and here further examine the kinetics of formation using a highly purified preparation of CYP2D6 in a reconstituted lipid system. Purified CYP2D6 protein with a measured molecular weight of 55772.0 (55769.6 Da predicted) was reconstituted into an active, lipid-vesicle environment with purified rat cytochrome P450 reductase before the addition of substrate and NADPH. Reaction kinetics were followed, and apparent Michaelis-Menten constants were determined for the appearance of each metabolite by high-pressure liquid chromatography, using both UV and fluorescence detection. In a 2-min assay, purified 2D6 catalyzed the formation of dextrorphan with an apparent K(m) value of 1.9 +/- 0.2 microM and a V(max) value of 8.5 +/- 0.2 nmol/nmol of P450/min and measured simultaneously the formation of 3-methoxymorphinan with an apparent K(m) value of 5000 +/- 700 microM and V(max) value of 176 +/- 12 nmol (nmol of P450)(-1) min(-1). These results indicate that at least two distinct binding orientations exist for dextromethorphan within the active site of CYP2D6.

Persantine improves acute pancreatitis in vitro

Persantine combined with TNF-a enhances antiproliferative activity in human tumor cells. We hypothesized that the vasodilator persantine would ameliorate acute pancreatitis (AP) in vitro. Rat pancreatic ductal cells were cultured using standard techniques. Acute pancreatitis was induced by adding cerulein (10(-9) M) or TNF-a (200 ng/ml). AP was verified by increased amylase production. Persantine was added at concentrations from 0.1 uM to 100 uM post cerulein or TNF-a treatment. Statistical analysis was achieved by ANOVA. Amylase production was significantly increased (p < 0.05) compared with control upon stimulation with either cerulein or TNF-a. When persantine was added in graded concentrations from 0.1 uM to 100 uM to cerulein treated cells, it decreased amylase production significantly (p < 0.05) at 100 uM. However, when persantine was added to TNF-a treated cells, it decreased amylase production (p < 0.05) at the lower concentrations of 0.1 uM and 1 uM. We have shown for the first time that AP, resulting from either mild (cerulein) or severe (TNF-a) stimulation, is significantly improved by treatment with persantine.

False increase in serum C-reactive protein caused by monoclonal IgM-lambda: a case report

Interference caused by human anti-animal antibodies has been described in many laboratory assays. Usually the antigen giving rise to these antibodies is not known. When present in sufficiently high titer, these antibodies may have a significant effect on laboratory assays, causing falsely increased or decreased values, to the detriment of patient care and laboratory diagnosis. We report a case of an 86-year old man who had greatly increased C-reactive protein (CRP) levels in serum (>500 mg/l), suggestive of an unusually strong inflammatory response such as seen in septicemia. Because this diagnosis was not consistent with his symptoms, CRP measurements were repeated using alternative methods, none of which gave CRP results higher than 12 mg/l. Protein electrophoresis followed by immunofixation showed a monoclonal IgM-lambda paraprotein (7 g/l), which bound the goat anti-CRP antibodies used in the first CRP assay. Precipitation of the IgM-lambda paraprotein eliminated the interference. Subsequent bone marrow tests did not reveal any blood malignancy, and the monoclonal IgM component was attributed to monoclonal gammopathy of unknown significance. In conclusion, an IgM-lambda paraprotein was shown to cause falsely elevated CRP values in an automated immunometric assay using goat anti-CRP antibodies.

Pancreatitis caused by common bile duct stones in a 3-year-old boy with prior surgery for a choledochal cyst

Pancreatitis in children is uncommon. Compared to adults, pancreatitis in children is usually related to trauma, anatomic anomalies, infections, hereditary, and systemic disease, but not gallstones or alcohol. Most cases do not require endoscopic intervention. We report an unusual case of recurrent pancreatitis in a child related to common bile duct stones requiring endoscopic treatments after surgical treatment for choledochal cyst.

Assessment of total energy expenditure in a Chinese population by a physical activity questionnaire: examination of validity

A physical activity questionnaire from which total daily energy expenditure (TEE) could be estimated was developed for adult Hong Kong Chinese subjects, and its reliability and validity examined. The questionnaire was based on questionnaires used in Caucasians, and adapted for local lifestyle after focus group meetings involving subjects of all age groups. The questionnaire was administered to 94 subjects, consisting of healthy adults, the elderly, and two patient groups (those with renal disease on continuous ambulatory peritoneal dialysis and those with cancer). Seventy-one subjects were reinterviewed within 14 days to test reliability. Validity was examined in 31 normal subjects by measuring the basal metabolic rate (BMR) by indirect calorimetry and multiplying by the physical activity level (PAL) obtained from published studies using the doubly labelled water method and also from FAO/WHO/UNU to obtain the TEE. The intraclass correlation coefficient of reliability rages from 0.7 to 0.8 for all subject groups. The mean estimated TEE from the questionnaire was not significantly different from the mean value derived from measured BMR x PAL. The mean bias ranged from an underestimation of 27 kcal to overestimation of 215 kcal. However, the limits of variability were wide. Age was inversely related to the energy expended for occupational activities, but was positively associated with energy expended in leisure activities. Women spent less energy on occupational and exercise activities, and more on caretaking activities. Those with disease were also less likely to participate in caretaking activities. We conclude that this questionnaire may be a useful tool for future studies where energy expenditure needs to be estimated in various settings in the Hong Kong Chinese population.

Accumulation of low molecular mass heparin during prophylactic treatment in pregnancy

A history of thromboembolism is associated with an increased risk of new thromboembolic events during pregnancy. Prophylaxis with heparin during pregnancy implicates long-term treatment with daily injections with either unfractionated heparin (UFH) or low molecular mass heparin (LMMH). Prolonged treatment with heparin may result in endothelial absorption and drug accumulation. In order to test this hypothesis, anti-FXa activity during pregnancy was measured in four women allergic to conventional UFH, who were treated with LMMH (dalteparin; Pharmacia). It was found that, at the commencement of treatment, it took more than 8 days to reach a steady maximum peak value, located 3 h after the given dose. One daily dosage of 5,000 IU anti-Xa resulted in a measurable level of FXa for 24 h in pregnancy week 40, compared with 17h at pregnancy week 37. The implications of an elevated anti-FXa activity during pregnancy, especially during the third trimester and at partus, are discussed. We present a reduced dose regime near term and during delivery.

Comparison of human genetic and sequence-based physical maps

Recombination is the exchange of information between two homologous chromosomes during meiosis. The rate of recombination per nucleotide, which profoundly affects the evolution of chromosomal segments, is calculated by comparing genetic and physical maps. Human physical maps have been constructed using cytogenetics, overlapping DNA clones and radiation hybrids; but the ultimate and by far the most accurate physical map is the actual nucleotide sequence. The completion of the draft human genomic sequence provides us with the best opportunity yet to compare the genetic and physical maps. Here we describe our estimates of female, male and sex-average recombination rates for about 60% of the genome. Recombination rates varied greatly along each chromosome, from 0 to at least 9 centiMorgans per megabase (cM Mb(-1)). Among several sequence and marker parameters tested, only relative marker position along the metacentric chromosomes in males correlated strongly with recombination rate. We identified several chromosomal regions up to 6 Mb in length with particularly low (deserts) or high (jungles) recombination rates. Linkage disequilibrium was much more common and extended for greater distances in the deserts than in the jungles.

Broad programming by IL-2 receptor signaling for extended growth to multiple cytokines and functional maturation of antigen-activated T cells

Coincident production of IL-2 and induction of high-affinity IL-2R upon TCR engagement has precluded a clear distinction for the biological outcome of signaling through TCR/costimulatory molecules vs the IL-2R. Using a novel transgenic mouse on the IL-2Rbeta(-/-) genetic background, this study has separated the relative outcome of signaling through the TCR and IL-2R. We show that stimulation through the TCR and CD28 or CD40 ligand directly leads to T cell activation and several rounds of proliferation in an IL-2-independent fashion. However, this stimulation is insufficient for extended T cell growth to multiple cytokines or differentiation into CTL or IFN-gamma-secreting effector T cells. IL-2 is required for these functions in part by regulation of cyclin D3 and granzyme B. Somewhat less efficiently, IL-4 stimulation of these transgenic T cells redundantly rescued many of these activities. These data demonstrate a fundamental requirement for IL-2 and perhaps other common gamma-chain-dependent cytokines to promote selective gene expression by Ag-activated T cells for their subsequent growth and differentiation into effector T lymphocytes.

The proteasome regulates receptor-mediated endocytosis of interleukin-2

Recent studies have increasingly implicated the proteasome in the regulation of cell surface receptors. In the present study, we investigated the role of the proteasome for ligand-dependent endocytosis and degradation of the interleukin-2 (IL-2)-interleukin-2 receptor (IL-2R) complex. Proteasome inhibitors impaired internalization of IL-2.IL-2R and prevented the lysosomal degradation of this cytokine. Based on time-course studies, proteasome activity is primarily required after initial endocytosis of the IL-2.IL-2R. Proteasome function was also necessary for the lysosomal degradation of IL-2 internalized by IL-2R that were comprised of cytoplasmic tailless beta- or gamma c-subunits, suggesting that the target protein for the proteasome is independent of either the cytoplasmic tail of the IL-2R beta- or gamma c-subunits and their associated signaling components. Therefore, a functional proteasome is required for optimal endocytosis of the IL-2R/ligand complex and is essential for the subsequent lysosomal degradation of IL-2, possibly by regulating trafficking to the lysosome.

Studies on common illnesses and medical care utilization patterns of adolescents in Hong Kong

PURPOSE

To estimate the prevalences of common illnesses in Hong Kong adolescents, the sociodemographic and selected risk factors associated with these illnesses, and their health care utilization behavior and attitudes.

METHODS

A cross-sectional questionnaire survey of 3355 participating secondary school students (response rate = 98%).

RESULTS

Self-reported 3-month prevalences were obtained for cough/cold/influenza (55.2%), digestive disorders (34.6%), accidental injuries (29.5%), headache/dizziness (23.6%), chronic anxiety/insomnia (20.1%), skin problems (9.5%), asthma (3.8%), liver disease (1.3%), and menstrual pain (13.8% of female students). Self-perceived poor health, smoking, and alcohol consumption were associated with many of these illnesses. Treatment choice depended on the illness suffered (e.g., most students with respiratory problems consulted medical practitioners, whereas most with chronic anxiety/insomnia did not). Many students lacked trust in their doctors, doctor-shopped, relied heavily on self-medication, did not comply with prescribed treatments, would not seek help about medical problems, felt they had insufficient access to health information, and wanted confidential health care.

CONCLUSIONS

This study examined for the first time the common illnesses and health care utilization patterns of Hong Kong adolescents. Students with chronic anxiety/insomnia were much less likely to seek care, indicating a need for better education on mental health. Efforts to prevent smoking and alcohol consumption among adolescents need to be strengthened. The students' attitudes, poor compliance and help-seeking behaviors suggest suboptimal use of the health care system. Our findings are useful for international comparisons by medical practitioners, health care managers, and researchers.

Chloride channel expression in cultured human fetal RPE cells: response to oxidative stress

PURPOSE

The human fetal cell line RPE 28 SV4 has been useful for studies of oxidative stress and apoptosis in retinal pigmented epithelium. This cell model is now assessed in functional investigations of chloride channel activity. The study aims to determine the presence of specific chloride channels, including CFTR and ClC channels, to identify the properties of membrane chloride currents and to assess their modulation by hydrogen peroxide, cAMP, and other agents.

METHODS

Channel expression was determined using RT-PCR and cDNA cloning and biochemical and immunocytochemical methods. Membrane currents were analyzed using whole-cell, patch-clamp techniques.

RESULTS

RT-PCR results confirmed the presence of ClC-5 mRNA, and a full-length clone encoding ClC-3 was isolated from a cDNA library for RPE 28 SV4 cells. Specific staining for CFTR and several ClC channels was detected by immunocytochemistry. Whole-cell chloride currents (under conditions of symmetrical chloride concentrations) averaged 16.9 +/- 3.4 pA/pF (at +100 mV; n = 8), showed outward rectification, and had an anion permeability sequence of Cl(-) > I(-) > cyclamate. Currents were stimulated by cAMP cocktail (250 microM cAMP, 100 microM IBMX, and 25 microM forskolin) and were inhibited by 1 mM DIDS. The oxidative agent hydrogen peroxide (100 microM) decreased the current by 34% +/- 10% (n = 4). CONCLUSIONS. These findings suggest that RPE 28 SV4 cells possess regulated chloride channels including CFTR and members of the ClC chloride channel family. The inhibition of chloride currents by H(2)O(2) suggests that this cell line may be advantageous for studies of chloride channel modulation by oxidative stress.

Hypoxia, HIF-1, and the pathophysiology of common human diseases

Hypoxia plays a fundamental role in the pathophysiology of common causes of mortality, including ischemic heart disease, stroke, cancer, chronic lung disease, and congestive heart failure. In these disease states, hypoxia induces changes in gene expression in target organs that either fail to result in adequate adaptation or directly contribute to disease pathogenesis. Hypoxia-inducible factor 1 (HIF-1) is a transcriptional activator that is expressed in response to cellular hypoxia and mediates multiple cellular and systemic homeostatic responses to hypoxia. Recent studies have provided evidence that important pathophysiological responses to hypoxia in pulmonary hypertension, myocardial ischemia, and cancer are mediated by HIF-1. Pharmacologic and gene therapy strategies designed to modulate HIF-1 activity may represent a novel and effective therapeutic approach to these common disorders.

Preferential externalization of newly synthesized phosphatidylserine in apoptotic U937 cells is dependent on caspase-mediated pathways

Externalization of phosphatidylserine (PtdSer) is a common feature of programmed cell death and plays an important role in the recognition and removal of apoptotic cells. In this study with U937 cells, PtdSer synthesis from [(3)H]serine was stimulated and newly synthesized PtdSer was transferred preferentially to cell-free medium vesicles (CFMV) from cells when apoptosis was induced with a topoisomerase I inhibitor, camptothecin (CAM). When CAM-induced apoptosis was blocked by a caspase inhibitor, z-VAD-fmk, stimulation of PtdSer synthesis and movement to CFMV were abolished. In contrast, changes in synthesis and transport of sphingomyelin (SM) or phosphatidylethanolamine (PtdEtn) were minor; total phosphatidylcholine (PtdCho) synthesis was below control levels. All phospholipids appeared in CFMV but PtdSer displayed a 6-fold increase relative to controls compared to 3-fold for SM, 2-fold for PtdCho and 1.8-fold for PtdEtn. Even greater effects on specificity of PtdSer synthesis, movement to CFMV and inhibition by z-VAD-fmk were observed in apoptotic cells induced by UV irradiation or tumor necrosis factor-alpha/cycloheximide treatment. Thus, PtdSer biosynthesis stimulated during apoptosis in U937 cells was specific for this phospholipid and was correlated with caspase-mediated exposure of PtdSer at the cell surface and preferential movement to vesicles during apoptosis.

Efficient internalization of IL-2 depends on the distal portion of the cytoplasmic tail of the IL-2R common gamma-chain and a lymphoid cell environment

The common gamma-chain (gammac), a subunit of the IL-2R, is essential for high affinity ligand binding and signal transduction due to Jak3 association to gammac. Another consequence of IL-2/IL-2R interaction is rapid receptor-mediated endocytosis of the receptor-ligand complex. In the present study, we establish that this rapid endocytosis of IL-2 in a T cell tumor line is dependent upon the cytoplasmic tail of gammac. Deletion mutants of the cytoplasmic tail mapped this activity to 9 aa of gammac, 45-54 aa distal to the transmembrane region. In contrast, ligand-independent constitutive endocytosis of gammac occurred more slowly and was dependent upon a PEST sequence in a more membrane-proximal region of the cytoplasmic tail of gammac. Thus, this receptor subunit may use distinct sorting signals for its constitutive regulation and ligand-induced endocytosis. Rapid endocytosis of IL-2 was inhibited by the tyrosine kinase inhibitor genistein, implicating a role for a signal transduction pathway in IL-2 internalization. However, one T cell line bearing a mutant gammac exhibited impaired endocytosis of IL-2, despite normal IL-2-induced Jak/STAT activation. Furthermore, inefficient endocytosis of IL-2 was noted after transfection of the COS7 epithelial cell line with the IL-2R, and further reconstitution of these cells with Jak/STAT proteins did not enhance this internalization. Collectively, these latter findings indicate that rapid endocytosis of IL-2 is dependent upon cellular signaling in lymphoid cell environment that is not solely a consequence of the presence of the Jak/STAT pathway.

The choice between Chinese medicine and Western medicine practitioners by Hong Kong adolescents

A survey of 3,355 Hong Kong adolescent students showed that the prevalence of TCM clinic consultation in a three-month period was 8.6%. Among students who sought doctor consultation in a three-month period, 17.8% consulted a TCM doctor. Students who sought doctor consultation for fall-related injuries were more likely to have consulted TCM doctors only, while those for skin disease were more likely to have consulted both TCM and western doctors. Perceived cost, efficacy, trust of western doctors and socioeconomic factors were not associated with choice of doctor type. Our findings are different from those on Hong Kong adults' use of health care services as reported in other studies.

Specific cell targeting for delivery of toxins into small-cell lung cancer using a streptavidin fusion protein complex

New modalities of treatment for small-cell lung cancer (SCLC) are needed, because the majority of patients continue to die of disseminated disease despite an initial response to conventional chemotherapy. Abnormal surface expression of the neural-cell adhesion molecule (NCAM) has been noted to be highly associated with SCLC. We examined the ability and efficiency of a streptavidin-Protein A (ST-PA) fusion protein complexed with an anti-NCAM monoclonal antibody (Mab) to transfer biotinylated beta-galactosidase into human SCLC cell lines NCI-H69, NCI-H526, and NCI-H446. When the surface molecule NCAM was targeted with this system, more than 99% of the targeted cells internalized and exhibited beta-galactosidase activity. In addition, we evaluated cytotoxic activity against SCLC lines NCI-H69 and NCI-H526 by efficient delivery of biotinylated glucose oxidase using the same ST-PA/anti-NCAM Mab complex. Cytotoxicity of the transduced cells (SCLC) was 10-fold and 100-fold greater, respectively, than the glucose oxidase control. This system could be widely applied for specific therapy of cancer cells by targeting unique surface molecules (antigens) using the corresponding Mab/ST-PA complex to transfer a variety of effector molecules; e.g., immunotoxic compounds, into target cells with a high degree of efficiency and specificity.

Activation of p53 or loss of the Cockayne syndrome group B repair protein causes metaphase fragility of human U1, U2, and 5S genes

Infection by adenovirus 12, transfection with the Ad12 E1B 55 kDa gene, or activation of p53 cause metaphase fragility of four loci (RNU1, PSU1, RNU2, and RN5S) each containing tandemly repeated genes for an abundant small RNA (U1, U2, and 5S RNA). We now show that loss of the Cockayne syndrome group B protein (CSB) or overexpression of the p53 carboxy-terminal domain induces fragility of the same loci; moreover, p53 interacts with CSB in vivo and in vitro. We propose that CSB functions as an elongation factor for transcription of structured RNAs, including some mRNAs. Activation of p53 would inhibit CSB, stalling transcription complexes and locally blocking chromatin condensation. Impaired transcription elongation may also explain the diverse clinical features of Cockayne syndrome.

[Place of value of pelvic lymphadenectomy for treatment of endometrial neoplasms]

OBJECTIVE

To explore the therapeutic value of pelvic lymphadenectomy for endometrial carcinoma.

METHODS

One hundred and four cases undergoing pelvic lymphadenectomy were analyzed. Comparisons were carried out between various clinicopathologic factors and incidence of positive node, between 5 years survival rate with pelvic lymphadenectomy and that without pelvic lymphadenectomy.

RESULTS

Four point four per cent case with positive node was found in clinical stage I cases. Positive node rate increased with deep myoinvasion and G3, accounting for 37.3% and 37.8% respectively. For clinical stage I and stage II cases, the 5 year survival rate of positive node and negative node was 38.9% and 74.2% respectively, with significant difference (P < 0.005). No significant difference was found between cases with pelvic lymphadenectomy and those without pelvic lymphadenectomy (P > 0.05) in pathologic stage I and stage II cases.

CONCLUSIONS

Positive pelvic node is an important prognostic factor in endometrial carcinoma. Pelvic lymphadenectomy can not improve prognosis in early stage patients with endometrial carcinoma. It is not necessary to perform pelvic lymphadenectomy for stage I case, because of low incidence of positive node.

Detection of methylthioadenosine phosphorylase (MTAP) and p16 gene deletion in T cell acute lymphoblastic leukemia by real-time quantitative PCR assay

Methylthioadenosine phosphorylase (MTAP) deficiency in tumors can be therapeutically exploited for selective therapy. Many tumors lacking MTAP have been found to homozygously delete the chromosome 9p region containing the p16 tumor suppressor gene. Several methods have been used to detect chromosome 9p deletions in primary tumors. However, the accurate diagnosis of chromosome 9p deletions has been hampered by the presence of contaminating normal cells. In search of an accurate and sensitive diagnostic method, we have developed the real-time polymerase chain reaction assay using the TaqMan chemistry for quantitative detection of MTAP and p16 gene deletions. The assay's feasibility was tested with peripheral blood leukocytes (PBL) from 29 patients with adult T cell leukemia (ATL) previously analyzed with Southern blot analysis and validated on 39 PBL or bone marrow samples from childhood T cell acute lymphoblastic leukemia (T-ALL). Homozygous deletions of MTAP and p16 genes were detected respectively in six (20.7%) and eight (27.6%) of 29 ATL samples and in 15 (38.5%) and 23 (59%) of 39 T-ALL samples. The results correlated well with those of Southern blot analysis. It is of significance that the newly developed method can successfully detect homozygous deletions of these genes in samples containing as low as 33% blast cells. This rapid and sensitive method may be useful in searching for candidates for selective therapy targeting MTAP deficiency.

Normal lymphoid homeostasis and lack of lethal autoimmunity in mice containing mature T cells with severely impaired IL-2 receptors

The importance of IL-2Rbeta function for immune regulation is highlighted by the severe impairment in lymphoid cell function in IL-2Rbeta-deficient mice. It has been speculated that failed IL-2/IL-2R signaling in peripheral T cells causes the associated autoimmunity, imbalanced peripheral lymphoid homeostasis, and defective T cell function. This study explored the requirement for IL-2Rbeta function in mature T lymphocytes. We show that transgenic thymic expression of the IL-2R beta-chain in IL-2Rbeta-deficient mice prevents lethal autoimmunity, restores normal production of B lymphocytes, and results in a peripheral T cell compartment that is responsive to triggering through the TCR, but not the IL-2R. The dysfunction of the IL-2R is illustrated by the near complete failure of mature T cells to proliferate to IL-2 in vitro and in vivo, to differentiate into CTL, and to up-regulate IL-2Ralpha expression. These data indicate that lymphoid homeostasis is largely maintained despite a nonfunctional IL-2R in mature T lymphocytes and suggest that IL-2Rbeta provides an essential signal during thymic development to regulate self-reactivity.

Imidazoline receptor agonist drugs for treatment of systemic hypertension and congestive heart failure

The imidazoline receptors recently have been discovered to be involved in the central nervous system control of sympathetic outflow. A new class of centrally acting antihypertensive agents, the imidazoline receptor agonists (rilmenidine and moxonidine), have been developed to control blood pressure effectively without the adverse effects of sedation and mental depression that usually are associated with centrally acting antihypertensive agents. This new generation of centrally acting antihypertensive agents is highly selective for the imidazoline receptor but has a low affinity for alpha(2)-adrenergic receptors. The usefulness of these agents in the treatment of congestive heart failure has not been demonstrated.

Conceptualization, reporting and underreporting of child abuse in Hong Kong

OBJECTIVE

To understand the conceptualization of child abuse and attitudes on reporting behaviors of Hong Kong adults.

METHODS

Cross-sectional telephone survey of 1,001 randomly selected subjects.

MAIN RESULTS

There is a discrepancy between perceived prevalence and the ability to name different child abuse types without prompting: 79.9% named physical abuse, while 41.2% felt it was common: 21.0% named child neglect, while 76.9% felt it was common; 13.4% named psychological abuse, while 47.4% felt it was common; 6.8% named sexual abuse, while 23.5% felt it was common. Most respondents classified severe physical abuse situations as abusive (e.g., "severely injuring a child"). Other scenarios such as "mildly injuring a child" and neglect and psychological abuse scenarios (e.g., "leaving a young child alone at home" and "shouting at a child often") were often not classified as abusive. As regards case-reporting behavior, only about 40% would report abuse cases to authorities. Those who would not report abuse were less likely to classify abuse situations as abusive and more likely to think that seeking help is difficult, troublesome and unhelpful.

CONCLUSIONS

The official reported prevalence figures for child abuse in Hong Kong should be interpreted with care, because underreporting is likely to be serious. Hong Kong people's conceptualization and awareness of what comprises child abuse is found to differ from official definitions. They are reluctant to report abuse cases, due to their perceived low efficacy of case reporting. Both the difference in conceptualization and the reluctance to report might partly be attributable to Chinese culture.

Cardiac specific overexpression of transglutaminase II (G(h)) results in a unique hypertrophy phenotype independent of phospholipase C activation

Tissue type transglutaminase (TGII, also known as G(h)) has been considered a multifunctional protein, with both transglutaminase and GTPase activity. The role of the latter function, which is proposed as a coupling mechanism between alpha(1)-adrenergic receptors and phospholipase C (PLC), is not well defined. TGII was overexpressed in transgenic mice in a cardiac specific manner to delineated relevant signaling pathways and their consequences in the heart. Cardiac transglutaminase activity in the highest expressing line was approximately 37-fold greater than in nontransgenic lines. However, in vivo signaling to PLC, as assessed by inositol phosphate turnover in [(3)H]myoinositol organ bath atrial preparations, was not increased in the TGII mice at base line or in response to alpha(1)-adrenergic receptor stimulation; nor was protein kinase Calpha (PKCalpha) or PKCepsilon activity enhanced in the TGII transgenic mice. This is in contrast to mice moderately (approximately 5-fold) overexpressing G(alphaq), where inositol phosphate turnover and PKC activity were found to be clearly enhanced. TGII overexpression resulted in a remodeling of the heart with mild hypertrophy, elevated expression of beta-myosin heavy chain and alpha-skeletal actin genes, and diffuse interstitial fibrosis. Resting ventricular function was depressed, but responsiveness to beta-agonist was not impaired. This set of pathophysiologic findings is distinct from that evoked by overexpression of G(alphaq). We conclude that TGII acts in the heart primarily as a transglutaminase, and modulation of this function results in unique pathologic sequelae. Evidence for TGII acting as a G-protein-like transducer of receptor signaling to PLC in the heart is not supported by these studies.