Priming of naive T cells inside tumors leads to eradication of established tumors

The tumor barrier comprised of nonantigenic stromal cells may contribute to the failure of tumor rejection. The tumor-necrosis factor superfamily member LIGHT (also known as TNFSF-14) is a ligand of stromal cell-expressed lymphotoxin-beta receptor and T cell-expressed herpes viral entry mediator (HVEM). Here we show that forced expression of LIGHT in the tumor environment induces a massive infiltration of naive T lymphocytes that correlates with an upregulation of both chemokine production and expression of adhesion molecules. Activation of these infiltrating T cells, possibly through HVEM, leads to the rejection of established, highly progressive tumors at local and distal sites. Our study indicates that targeting the tumor barrier may be an effective strategy for cancer immunotherapy.

Lymphotoxin is required for maintaining physiological levels of serum IgE that minimizes Th1-mediated airway inflammation

Although elevated levels of IgE in asthmatic patients are strongly associated with lung infiltration by activated T helper (Th) 2 cells, the physiological role of immunoglobulin E (IgE) in the airway remains largely undefined. Lymphotoxin-deficient α (LTα^−/−) mice exhibit increased airway inflammation, paradoxically accompanied by diminished levels of IgE and reduced airway hyperresponsiveness in response to both environmental and induced antigen challenge. The severe lung inflammation in LTα^−/− mice is Th1 in nature and can be alleviated by IgE reconstitution. Conversely, depletion of IgE in wild-type mice recapitulates the lung pathologies of LTα^−/− mice. Therefore, this work has revealed that lymphotoxin is essential for IgE production, and a physiological role of IgE in the airway may consist of maintaining the balance of Th1 and Th2 responses to prevent aberrant inflammation.

Differential regulation of CCL21 in lymphoid/nonlymphoid tissues for effectively attracting T cells to peripheral tissues

CC chemokine ligand 21 (CCL21)/secondary lymphoid chemokine (SLC), a ligand for CC chemokine receptor 7 (CCR7), has been demonstrated to play a vital role in the homing and localization of immune cells to lymphoid tissues, but its role in nonlymphoid tissues largely remains undefined. Here, we provide evidence that CCL21 in lymphoid and nonlymphoid tissues is differentially regulated by lymphotoxin-dependent (LT-dependent) and -independent mechanisms, respectively. This differential regulation is due to the selective regulation of the CCL21-Ser/CCL21a but not the CCL21-Leu/CCL21b gene by the LT and noncanonical NF-kappaB pathways. This alternate pathway, not dependent on LT or lymphocytes, leading to constitutive expression of CCL21 in nonlymphoid tissues, is critical for the initial recruitment of T lymphocytes to peripheral effector sites. CCL21 expression is subsequently further enhanced in a LT-dependent fashion following airway challenge, potentially facilitating a positive feedback loop to attract additional CCR7+ effector cells. These findings establish an essential role for CCL21 in the recruitment of effector T cells to peripheral tissues and suggest that LT-dependent and -independent regulation of CCL21 plays a role in balancing the central and peripheral immune responses between lymphoid and nonlymphoid tissues.

Lymphotoxin pathway directs thymic Aire expression

The autoimmune regulator Aire is a key mediator of central tolerance for peripherally restricted antigens. Its absence in human patients results in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy. The cellular signals that regulate Aire expression are undefined. We show here that lymphotoxin signaling is necessary for the expression of Aire and its downstream target genes. The failure of Aire induction in the thymi of lymphotoxin-deficient and lymphotoxin-beta receptor-deficient mice contributes to overt autoimmunity against self antigens normally protected by Aire. Conversely, stimulation of lymphotoxin-beta receptor by agonistic antibody leads to increased expression of Aire and tissue-restricted antigens in both intact thymi and cultured thymic epithelial cell line. These findings define the essential cross-talk between thymocytes and thymic stroma that is required for central tolerance.

CD4 dependence of gp120IIIB-CXCR4 interaction is cell-type specific

The HIV-1 envelope protein gp120IIIB is selective for the CXCR4 chemokine receptor and has been shown to induce apoptosis in neurons both in vivo and in vitro. We examined the ability of gp120IIIB to signal through the rat CXCR4 (rCXCR4) receptor and its dependence on the presence of the human CD4 (hCD4) protein in a number of cell systems. SDF-1alpha potently inhibited N-type Ca channels in cultured HEK293 cells expressing both the Ca channel subunits and rCXCR4 receptors. However, gp120IIIB was ineffective in producing either Ca channel inhibition or in blocking the effects of SDF-1alpha. However, when hCD4 was coexpressed with rCXCR4 and Ca channel subunits, gp120IIIB also produced Ca channel inhibition. Similarly, in PC12 cells transfected with the rCXCR4, SDF-1alpha produced mobilization of intracellular Ca, while gp120IIIB was only effective when hCD4 was coexpressed. SDF-1alpha induced endocytosis of Yellow Fluorescent Protein (YFP)-tagged rCXCR4 expressed in PC12 cells, as did gp120IIIB, an effect which was enhanced by hCD4 coexpression. When tagged rCXCR4 was expressed in F-11 cells or in rat DRG neurons, SDF-1alpha produced extensive receptor endocytosis. However, the ability of gp120IIIB to produce endocytosis was dependent on the coexpression of hCD4. Our results demonstrate that the degree of hCD4 dependence of the agonist effects of gp120IIIB at the rCXCR4 receptor is cell-type specific.

Signaling via LTbetaR on the lamina propria stromal cells of the gut is required for IgA production

Peyer's patches (PPs) and/or mesenteric lymph nodes (MLNs) are thought to be essential for immunoglobulin A (IgA) production. We found that the severe IgA deficiency in lymphotoxin-deficient (LT(-/-)) mice could be fully reversed by reconstitution with LT-expressing bone marrow, despite the absence of both LNs and PPs. The number of IgA precursors from LT(-/-) mice was not reduced, and they were able to migrate into the lamina propria (LP) of wild-type mice but not of LTbetaR(-/-) mice. Consistently, lymphoid tissue chemokines and adhesion molecules were reduced within the LP of LTalpha(-/-) and LTbetaR(-/-) mice. IgA deficiency in LTalpha(-/-) mice was reversed by the transplantation of a segment of RAG-1 (recombination-activating gene 1) deficient intestine, which confirmed the dispensability of the MLNs and PPs and the sufficiency of the LT-mediated gut microenvironment for IgA production.

B cells control the migration of a subset of dendritic cells into B cell follicles via CXC chemokine ligand 13 in a lymphotoxin-dependent fashion

Certain classes of dendritic cells (DCs) meet rare cognate Ag-specific T and B cells inside primary B cell follicles for the development of germinal centers. However, the mechanisms underlying this coordination are still undefined. Cysteine-rich (CR) domain of the mannose receptor (CR-Fc)(+) DCs are a newly discovered subset of DCs that migrate rapidly into the primary lymphoid follicles from marginal zone after immunization. In this work, we uncover the key role of B cells in the establishment of a microenvironment that allows these DCs to be in the B cell area in a lymphotoxin (LT)-dependent fashion. CR-Fc(+) DCs are absent from the spleens of both LTbetaR- and LTalpha-deficient mice, suggesting that signaling by membrane LT is required for the presence of CR-Fc(+) DCs in the spleen. Interestingly, analysis of mutant mice that lack T, B, or NK cells demonstrates that B cell-derived membrane LT is essential for the unique localization of CR-Fc(+) DCs in the spleen. Using bone marrow transfer and ligand-blocking approaches, we provide evidence that B cell-derived LT acts indirectly on CR-Fc(+) DCs through LTbetaR(+) stromal cells. In analogous fashion to certain Ag-activated T and B cells, CR-Fc(+) DCs, expressing CXCR5, localize to primary lymphoid follicles in response to CXC ligand 13 (B lymphocyte chemoattractant). Together, we propose that B cells play a central role in establishing the chemotactic gradient that attracts not only Ag-activated T and B cells but also Ag-carrying CR-Fc(+) DCs. In turn, CR-Fc(+) DCs and T cells home to B cell follicles to interact with B cells in the developing germinal center.

E1A transformed normal human prostate epithelial cells contain a 16q deletion

The difficulty of maintaining long-term prostate cell cultures has hindered the development of essential models for understanding prostate cancer. We report here the establishment of two 12S E1A transformed non-tumorigenic prostate epithelial cell strains, and their characterization. The two clonal cell strains, TP2 and TP4, proliferated for approximately 40 passages before senescence. Both exhibited a strong dependence on exogenous peptide growth factors and an immunophenotype characteristic of their prostate epithelial origin. Cytogenetic analysis revealed a consistent deletion on the q arm of chromosome 16 in TP2 with an otherwise normal karyotype. Band-specific microdissection generated region-specific probes from 16q23, which when used in fluorescence in situ hybridization (FISH) revealed that the region was deleted in 83% of metaphases analyzed. By cytogenetic analysis and FISH, the q arm of 16 was found deleted from the genome of TP4 in 60% of cells analyzed. Lost sequences on 16q-16q23 in particular--in prostate cancer have been observed by a variety of methods. Localization of common region of deletion has been determined from these studies to be distal to 16q23. Our findings suggest that 16q23 may be of major importance in the development of prostate cancer, and may harbor tumor suppressor elements.

Relationship between newborn and maternal iron status and haematological indices

The haemoglobin, mean corpuscular volume, mean corpuscular haemoglobin, haematocrit, serum iron and total iron binding capacity, and serum ferritin concentrations in umbilical cord blood samples taken from 96 appropriate-for-gestational age infants delivered at term were measured and compared to the respective maternal values measured at 36 weeks' gestation. All the values were higher in cord blood. Only maternal mean corpuscular volume and mean corpuscular haemoglobin were correlated with cord serum iron. Cord blood haematological indices were not correlated with either gestation at delivery or birth weight. However, newborn serum ferritin was positively correlated with gestation at delivery, while the maternal:newborn ferritin ratio was inversely correlated with gestation and birth weight. The results suggest that maternal haematological and iron indices are not predictive of the haemoglobin or iron status of the newborn, and that the fetus continues to take up iron from the mother until delivery.

Second-trimester thyroid function and pregnancy outcome in mothers with hyperthyroidism. Birth weight related to mid-trimester triiodothyronine and RBC zinc

Thyroid function at 24-28 weeks gestation was compared between 26 mothers with hyperthyroidism (16 on antithyroid treatment and 10 in remission without treatment) and 15 normal pregnant controls. There was no difference in the total and free thyroxine (TT4 and FT4) or in the total and free triiodothyronine (TT3 and FT3) concentrations, but the erythrocyte zinc (RBC Zn) concentration was significantly lower in the study group (187.3 +/- 46.6 mumol/l RBC versus 223.6 +/- 3.7 mumol/l RBC, p less than 0.01). In the study group, both birth weight and gestation at delivery were significantly correlated with TT3 (r = -0.500, p less than 0.02 and r = -0.460, p less than 0.05, respectively) as well as with RBC Zn (r = 0.473, p less than 0.02 and r = 0.573, p less than 0.01, respectively). The results suggest that plasma concentration of TT3 and of RBC Zn at 24-28 weeks gestation may be helpful prognostic factors in the management of pregnant patients with hyperthyroidism.

The role of transcutaneous electrical nerve stimulation in management of labour in obstetric patients

The study evaluated the effect of transcutaneous electrical nerve stimulation (TENS) in the management of labour. It comprised of 125 subjects with 93 primiparae and 32 multiparae. They were divided into 3 groups. The first group received electrical stimulation from the TENS unit (TENS); the second group (placebo group) had the TENS machine connected but with no current from the TENS unit (TPL); whereas the third group had no machine application (control group). Analgesic requirements, pain assessment, labour duration, Obstetric outcome, and the comments from mother and midwife were analysed. No negative effects on the mothers and babies were reported. Neither was there any objective clinical significant differences demonstrated among the 3 groups.

Plasma and erythrocyte zinc and birth weight in pre-eclamptic pregnancies

Plasma and erythrocyte zinc concentrations in 45 proteinuric pre-eclamptic Chinese women were measured. There was no difference in either the plasma or erythrocyte zinc concentration between pre-eclamptic patients with and without intrauterine growth retardation. There was no correlation between either plasma or erythrocyte zinc concentration with the gestation at delivery, birth weight, mean arterial pressure and plasma albumin concentration. On the other hand, both plasma albumin concentration and mean arterial pressure were significantly correlated to birth weight, and the mean arterial pressure was also significantly higher in patients with intrauterine growth retardation. Plasma and erythrocyte zinc are not useful as indices of severity in pre-eclampsia.

Maternal thyroid hormones and outcome of pre-eclamptic pregnancies

Plasma concentrations of total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3), thyroid-stimulating hormone (TSH), plasma albumin and urate were measured in 39 proteinuric pre-eclamptic patients presenting before labour. Pre-eclamptic patients had significantly lower FT4 and higher TSH concentrations compared with values in third trimester normotensive pregnancies. There was a significantly higher frequency of lower TT4, TT3 and high TSH levels in the subgroup of pre-eclamptic patients who had low-birthweight babies. Thyroid hormone concentrations were not correlated with gestation at delivery or birthweight but, with the exception of FT4, were correlated with plasma albumin and urate concentrations. Plasma TSH correlated with birthweight and with plasma urate. The results suggest that mild biochemical hypothyroidism may be found in proteinuric pre-eclampsia, and the concentrations of TT4, TT3, FT3 and TSH may reflect the severity of pre-eclampsia.

A longitudinal study of changes in erythrocyte zinc concentration in hyperemesis gravidarum

Erythrocyte zinc concentration and plasma thyroid hormones were measured in 32 patients admitted to hospital because of hyperemesis gravidarum. At presentation, 8 patients had elevated total and free thyroxine concentrations. The initial erythrocyte zinc concentration in these 8 patients was not different from the others, but in 5 of them, a transient drop in the erythrocyte zinc concentration was observed 2-12 weeks later, and which returned to normal towards the end of pregnancy. The lowest erythrocyte zinc concentration in the hyperthyroxinaemic group (171.0 +/- 31.7 mumol/l of RBC) was significantly lower than that of the normothyroxinaemic group (214.2 +/- 33.9 mumol/l of RBC) (p less than 0.01). This indicates that hyperthyroxinaemia in patients with hyperemesis gravidarum represents true hyperthyroidism, but is different from classical thyrotoxicosis in that the elevation of thyroid hormones is transient.

Pregnancy outcome in women with labor-onset hypertension. Similar outcome between labor-onset hypertension and preeclampsia

Labor-onset hypertension is a poorly documented category, and there is scanty information concerning the outcome of pregnancy in this condition. A retrospective study was performed to compare the pregnancy outcome of 36 patients with labor-onset hypertension (group A) with 36 patients with classical preeclampsia diagnosed before labor (group B) who were matched for parity and age. There was no difference in age, past history of hypertensive pregnancies or family history of hypertension between the two groups. The need for intrapartum hypertensive and anticonvulsant treatment as well as the outcome of pregnancy were similar in both groups. The only significant difference was that group A patients had lower maximum and booking systolic and diastolic pressures. The results indicate that labor-onset hypertension represents a late manifestation of the preeclampsia process, because these patients had lower blood pressure in pregnancy and would not be identified until intrapartum elevation of blood pressure satisfied the diagnostic criteria of preeclampsia.

Zinc and birth weight in uncomplicated pregnancies

The relationship between zinc status and birth weight in uncomplicated pregnancies was studied in 59 nulliparous and 27 multiparous Chinese women with singleton pregnancies, delivered at term. Maternal and umbilical cord blood, maternal pubic hair and a segment of the umbilical cord were collected at delivery for analysis. The zinc concentration was significantly higher (p less than 0.0001) in the plasma of newborn infants (13.9 +/- 2.8 mumol/l) than in maternal plasma (9.3 +/- 2.2 mumol/l), while the converse was found in tissue (60.8 +/- 17.0 vs 208.1 +/- 96.2 micrograms/g, p less than 0.0001). There was no significant correlation between birth weight and either maternal or newborn plasma or tissue zinc concentrations. Parity had no significant effect on maternal or newborn zinc concentrations in tissue and plasma.

Antenatal complications and perinatal outcome in patients with nausea and vomiting-complicated pregnancy

The incidence of nausea and vomiting-complicated pregnancy was determined in a district hospital in Hong Kong. Nausea was present in 11.4% and vomiting in 63.5% of pregnant women. Patients with vomiting complicating early pregnancy have a statistically significant higher incidence of antepartum haemorrhage of indeterminate origin. The incidences of medical diseases complicating pregnancy, other major antenatal complications, and the neonatal outcome were not different between vomiting and non-vomiting patients.

Single dose prophylactic antibiotics in caesarean sections

A prospective, double-blind randomized trial was carried out at the Department of Obstetrics and Gynaecology, the Chinese University of Hong Kong, involving 4 groups of patients receiving a single intravenous dose of placebo, ampicillin, ampicillin and metronidazole, and ampicillin and sulbactam before operation. No difference in postoperative morbidity was present between the 4 groups of patients.