Toll-like receptor-2 mediates lipopolysaccharide-induced cellular signalling

Vertebrates and invertebrates initiate a series of defence mechanisms following infection by Gram-negative bacteria by sensing the presence of lipopolysaccharide (LPS), a major component of the cell wall of the invading pathogen. In humans, monocytes and macrophages respond to LPS by inducing the expression of cytokines, cell-adhesion proteins, and enzymes involved in the production of small proinflammatory mediators. Under pathophysiological conditions, LPS exposure can lead to an often fatal syndrome known as septic shock. Sensitive responses of myeloid cells to LPS require a plasma protein called LPS-binding protein and the glycosylphosphatidylinositol-anchored membrane protein CD14. However, the mechanism by which the LPS signal is transduced across the plasma membrane remains unknown. Here we show that Toll-like receptor 2 (TLR2) is a signalling receptor that is activated by LPS in a response that depends on LPS-binding protein and is enhanced by CD14. A region in the intracellular domain of TLR2 with homology to a portion of the interleukin (IL)-1 receptor that is implicated in the activation of the IL-1-receptor-associated kinase is required for this response. Our results indicate that TLR2 is a direct mediator of signalling by LPS.

The outbreak of West Nile virus infection in the New York City area in 1999

BACKGROUND

In late August 1999, an unusual cluster of cases of meningoencephalitis associated with muscle weakness was reported to the New York City Department of Health. The initial epidemiologic and environmental investigations suggested an arboviral cause.

METHODS

Active surveillance was implemented to identify patients hospitalized with viral encephalitis and meningitis. Cerebrospinal fluid, serum, and tissue specimens from patients with suspected cases underwent serologic and viral testing for evidence of arboviral infection.

RESULTS

Outbreak surveillance identified 59 patients who were hospitalized with West Nile virus infection in the New York City area during August and September of 1999. The median age of these patients was 71 years (range, 5 to 95). The overall attack rate of clinical West Nile virus infection was at least 6.5 cases per million population, and it increased sharply with age. Most of the patients (63 percent) had clinical signs of encephalitis; seven patients died (12 percent). Muscle weakness was documented in 27 percent of the patients and flaccid paralysis in 10 percent; in all of the latter, nerve conduction studies indicated an axonal polyneuropathy in 14 percent. An age of 75 years or older was an independent risk factor for death (relative risk adjusted for the presence or absence of diabetes mellitus, 8.5; 95 percent confidence interval, 1.2 to 59.1), as was the presence of diabetes mellitus (age-adjusted relative risk, 5.1; 95 percent confidence interval, 1.5 to 17.3).

CONCLUSIONS

This outbreak of West Nile meningoencephalitis in the New York City metropolitan area represents the first time this virus has been detected in the Western Hemisphere. Given the subsequent rapid spread of the virus, physicians along the eastern seaboard of the United States should consider West Nile virus infection in the differential diagnosis of encephalitis and viral meningitis during the summer months, especially in older patients and in those with muscle weakness.

Genomic amplification of a decoy receptor for Fas ligand in lung and colon cancer

Fas ligand (FasL) is produced by activated T cells and natural killer cells and it induces apoptosis (programmed cell death) in target cells through the death receptor Fas/Apol/CD95. One important role of FasL and Fas is to mediate immune-cytotoxic killing of cells that are potentially harmful to the organism, such as virus-infected or tumour cells. Here we report the discovery of a soluble decoy receptor, termed decoy receptor 3 (DcR3), that binds to FasL and inhibits FasL-induced apoptosis. The DcR3 gene was amplified in about half of 35 primary lung and colon tumours studied, and DcR3 messenger RNA was expressed in malignant tissue. Thus, certain tumours may escape FasL-dependent immune-cytotoxic attack by expressing a decoy receptor that blocks FasL.

A novel receptor for Apo2L/TRAIL contains a truncated death domain

Apo2 ligand (Apo2L [1], also called TRAIL for tumor necrosis factor (TNF)-related apoptosis-inducing ligand [2]) belongs to the TNF family and activates apoptosis in tumor cells. Three closely related receptors bind Apo2L: DR4 and DR5, which contain cytoplasmic death domains and signal apoptosis, and DcR1, a decoy receptor that lacks a cytoplasmic tail and inhibits Apo2L function [3-5]. By cross-hybridization with DcR1, we have identified a fourth Apo2L receptor, which contains a cytoplasmic region with a truncated death domain. We subsequently named this protein decoy receptor 2 (DcR2). The DcR2 gene mapped to human chromosome 8p21, as did the genes encoding DR4, DR5 and DcR1. A single DcR2 mRNA transcript showed a unique expression pattern in human tissues and was particularly abundant in fetal liver and adult testis. Upon overexpression, DcR2 did not activate apoptosis or nuclear factor-kappaB; however, it substantially reduced cellular sensitivity to Apo2L-induced apoptosis. These results suggest that DcR2 functions as an inhibitory Apo2L receptor.

Adverse events associated with prescription drug cost-sharing among poor and elderly persons

CONTEXT

Rising costs of medications and inequities in access have sparked calls for drug policy reform in the United States and Canada. Control of drug expenditures by prescription cost-sharing for elderly persons and poor persons is a contentious issue because little is known about the health impact in these subgroups.

OBJECTIVES

To determine (1) the impact of introducing prescription drug cost-sharing on use of essential and less essential drugs among elderly persons and welfare recipients and (2) rates of emergency department (ED) visits and serious adverse events associated with reductions in drug use before and after policy implementation.

DESIGN AND SETTING

Interrupted time-series analysis of data from 32 months before and 17 months after introduction of a prescription coinsurance and deductible cost-sharing policy in Quebec in 1996. Separate 10-month prepolicy control and postpolicy cohort studies were conducted to estimate the impact of the drug reform on adverse events.

PARTICIPANTS

A random sample of 93 950 elderly persons and 55 333 adult welfare medication recipients.

MAIN OUTCOME MEASURES

Mean daily number of essential and less essential drugs used per month, ED visits, and serious adverse events (hospitalization, nursing home admission, and mortality) before and after policy introduction.

RESULTS

After cost-sharing was introduced, use of essential drugs decreased by 9.12% (95% confidence interval [CI], 8.7%-9.6%) in elderly persons and by 14.42% (95% CI, 13.3%-15.6%) in welfare recipients; use of less essential drugs decreased by 15.14% (95% CI, 14.4%-15.9%) and 22.39% (95% CI, 20.9%-23.9%), respectively. The rate (per 10 000 person-months) of serious adverse events associated with reductions in use of essential drugs increased from 5.8 in the prepolicy control cohort to 12.6 in the postpolicy cohort in elderly persons (a net increase of 6.8 [95% CI, 5.6-8.0]) and from 14.7 to 27.6 in welfare recipients (a net increase of 12.9 [95% CI, 10.2-15.5]). Emergency department visit rates related to reductions in the use of essential drugs also increased by 14.2 (95% CI, 8.5-19.9) per 10 000 person-months in elderly persons (prepolicy control cohort, 32.9; postpolicy cohort, 47.1) and by 54.2 (95% CI, 33.5-74.8) among welfare recipients (prepolicy control cohort, 69.6; postpolicy cohort, 123.8). These increases were primarily due to an increase in the proportion of recipients who reduced their use of essential drugs. Reductions in the use of less essential drugs were not associated with an increase in risk of adverse events or ED visits.

CONCLUSIONS

In our study, increased cost-sharing for prescription drugs in elderly persons and welfare recipients was followed by reductions in use of essential drugs and a higher rate of serious adverse events and ED visits associated with these reductions.

Ascorbic acid enhances endothelial nitric-oxide synthase activity by increasing intracellular tetrahydrobiopterin

Ascorbic acid enhances NO bioactivity in patients with vascular disease through unclear mechanism(s). We investigated the role of intracellular ascorbic acid in endothelium-derived NO bioactivity. Incubation of porcine aortic endothelial cells (PAECs) with ascorbic acid produced time- and dose-dependent intracellular ascorbic acid accumulation that enhanced NO bioactivity by 70% measured as A23187-induced cGMP accumulation. This effect was due to enhanced NO production because ascorbate stimulated both PAEC nitrogen oxide (NO(2)(-) + NO(3)(-)) production and l-arginine to l-citrulline conversion by 59 and 72%, respectively, without altering the cGMP response to authentic NO. Ascorbic acid also stimulated the catalytic activity of eNOS derived from either PAEC membrane fractions or baculovirus-infected Sf9 cells. Ascorbic acid enhanced bovine eNOS V(max) by approximately 50% without altering the K(m) for l-arginine. The effect of ascorbate was tetrahydrobiopterin (BH(4))-dependent, because ascorbate was ineffective with BH(4) concentrations >10 microm or in PAECs treated with sepiapterin to increase intracellular BH(4). The effect of ascorbic acid was also specific because A23187-stimulated cGMP accumulation in PAECs was insensitive to intracellular glutathione manipulation and only ascorbic acid, not glutathione, increased the intracellular concentration of BH(4). These data suggest that ascorbic acid enhances NO bioactivity in a BH(4)-dependent manner by increasing intracellular BH(4) content.

Cloning and characterization of IL-17B and IL-17C, two new members of the IL-17 cytokine family

IL-17 is a T cell-derived cytokine that may play an important role in the initiation or maintenance of the proinflammatory response. Whereas expression of IL-17 is restricted to activated T cells, the IL-17 receptor is found to be widely expressed, a finding consistent with the pleiotropic activities of IL-17. We have cloned and expressed two novel human cytokines, IL-17B and IL-17C, that are related to IL-17 ( approximately 27% amino acid identity). IL-17B mRNA is expressed in adult pancreas, small intestine, and stomach, whereas IL-17C mRNA is not detected by RNA blot hybridization of several adult tissues. No expression of IL-17B or IL-17C mRNA is found in activated T cells. In a survey of cytokine induction, IL-17B and IL-17C stimulate the release of tumor necrosis factor alpha and IL-1beta from the monocytic cell line, THP-1, whereas IL-17 has only a weak effect in this system. No induction of IL-1alpha, IL-6, IFN-gamma, or granulocyte colony-stimulating factor is found in THP-1 cells. Fluorescence-activated cell sorter analysis shows that IL-17B and IL-17C bind to THP-1 cells. Conversely, IL-17B and IL-17C are not active in an IL-17 assay or the stimulation of IL-6 release from human fibroblasts and do not bind to the human IL-17 receptor extracellular domain. These data show that there is a family of IL-17-related cytokines differing in patterns of expression and proinflammatory responses that may be transduced through a cognate set of cell surface receptors.

FGF-19, a novel fibroblast growth factor with unique specificity for FGFR4

We have identified a novel fibroblast growth factor, FGF-19, the most distant member of the FGF family described to date. FGF-19 is a high affinity, heparin dependent ligand for FGFR4 and is the first member of the FGF family to show exclusive binding to FGFR4. Human FGF-19 maps to chromosome 11 q13.1, a region associated with an osteoporosis-pseudoglioma syndrome of skeletal and retinal defects. FGF-19 message is expressed in several tissues including fetal cartilage, skin, and retina, as well as adult gall bladder and is overexpressed in a colon adenocarcinoma cell line.

Treatment of hypertension with ascorbic acid

In a randomised, double-blind, placebo-controlled study we showed that treatment of hypertensive patients with ascorbic acid lowers blood pressure. Further studies of ascorbic acid to treat hypertension, with clinical endpoints, are warranted.

The differentiated form of nasopharyngeal carcinoma contains Epstein-Barr virus DNA

Immunologic studies of Epstein-Barr virus (EBV) have implicated EBV in undifferentiated and partially differentiated, non-keratinizing nasopharyngeal carcinoma (NPC). Patients with the well-differentiated, keratinizing form of NPC have EBV serologic patterns similar to those of control populations. In addition, viral DNA has not been detected in the differentiated tumors using viral cRNA probes to DNA immobilized on filters. In this study we have tested for EBV DNA using recombinant DNA probes to Southern blots of DNA from 33 NPC specimens. The 24 undifferentiated and 4 partially differentiated specimens generally contained a relatively high number of EBV genome equivalents, while the 5 well-differentiated NPC all contained detectable EBV, but at low copy number. The viral DNA from one of the well-differentiated specimens was cloned into a cosmid vector. Five recombinant clones representing the fused viral termini were obtained, indicating the presence of episomal, intracellular DNA in the tumor. These findings indicate that all histologic subsets of NPC contain EBV DNA.

Exercise training augments flow-dependent dilation in rat skeletal muscle arterioles. Role of endothelial nitric oxide and prostaglandins

We aimed to test the hypothesis that as a consequence of short-term daily exercise, flow (shear stress)-dependent dilation and its mediation by the endothelium are altered in skeletal muscle arterioles. After initial familiarization with the protocol, rats ran on a treadmill once a day (with gradually increasing intensity up to 40 minutes and 28 m/min) for approximately 3 weeks (EX group); a control group remained sedentary (SED group). The active (internal) diameters of isolated gracilis muscle arterioles of SED and EX rats at 80 mm Hg were significantly different (55.2 +/- 2.1 and 49.3 +/- 2.0 microns, P < .05), and their passive diameters (in Ca(2+)-free solution) were 105.3 +/- 3.1 and 111.2 +/- 2.4 microns (not significantly different), respectively. Increases in flow of the perfusion solution from 0 to 12 microL/min elicited a significantly greater increase in diameter of EX arterioles (by 83.5% at maximum flow). This enhanced sensitivity maintained a lower shear stress in EX arterioles (15 to 20 dyne/cm2) compared with SED arterioles (25 to 35 dyne/cm2). In both SED and EX arterioles, flow-dependent dilation was eliminated after removal of the endothelium. Either N omega-nitro-L-arginine, a nitric oxide synthase inhibitor, or indomethacin, an inhibitor of prostaglandin synthesis, shifted the flow-diameter and calculated wall shear stress-diameter curves significantly to the right. Each of the inhibitors reduced flow-dependent dilation to a similar degree (approximately 40% to 45%); their combined administration nearly completely eliminated the dilation of arterioles of both SED and EX rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum tryptophan decrease correlates with immune activation and impaired quality of life in colorectal cancer

Cancer-related indoleamine (2,3)-dioxygenase up-regulation by interferon-gamma might influence quality of life by depleting serum tryptophan. We correlated serum tryptophan levels with immune activation and quality of life in patients with colorectal liver metastases. Venous blood was sampled from patients with primary colorectal cancer and from patients with metachronous colorectal liver metastases who completed quality of life and psychological questionnaires. Serum tryptophan, kynurenine, neopterin, interleukin 2 soluble receptor alpha (IL-2 sRalpha), soluble tumour necrosis factor receptor I (sTNF RI), interleukin 6, and C-reactive protein were measured. Liver metastasis volume was estimated by computerised tomography, and survival from blood sampling was noted. Sixty-six patients with colorectal cancer were studied (39 males; median age 66 years) of whom 25 had colorectal liver metastases only (17 males; median age 62 years; median liver metastasis volume 208 ml; median survival 234 days). Reduced serum tryptophan was significantly associated with Rotterdam Symptom Checklist physical symptom (r=-0.51, P=0.01) and Sickness Impact Profile (r=-0.42, P=0.04) scores, and correlated with increased serum neopterin (r=-0.36, P=0.003), IL-2 sRalpha (r=-0.51, P=0.01) and sTNF RI (r=-0.45, P=0.02) levels. Stepwise regression analyses suggested that serum tryptophan was an independent predictor of Rotterdam Symptom Checklist physical symptom (regression coefficient -20.78, P=0.01) and Sickness Impact Profile (regression coefficient -109.09, P=0.04) scores. The results supported a role for interferon-gamma-mediated serum tryptophan decrease in cancer-induced quality of life deterioration.

Adrenal masses: correlation between CT attenuation value and chemical shift ratio at MR imaging with in-phase and opposed-phase sequences

PURPOSE

To correlate attenuation values at computed tomography (CT) with signal intensity at chemical-shift magnetic resonance (MR) imaging in adrenal masses.

MATERIALS AND METHODS

Thirty-eight patients with 47 adrenal lesions underwent MR imaging and unenhanced CT examinations. MR examinations, performed at 1.5 T, included T1-weighted imaging with fat and water in phase and gradient-echo imaging with fat and water out of phase (repetition time, 45-180 msec; echo time, 1.4-3.1 msec). Lesion-to-spleen signal intensity ratios were calculated for the in-phase and opposed-phase images. The chemical-shift ratio, a measure of signal intensity loss between in-phase and opposed-phase images, and the CT attenuation value (in Hounsfield units) were determined for each lesion.

RESULTS

A statistically significant correlation (0.85) was found between attenuation and chemical-shift-ratio values (P < .000001). Attenuation in six benign lesions was within 2 standard deviations of the mean attenuation in malignant lesions, and the chemical-shift ratio in eight benign lesions was within 2 standard deviations of the mean chemical-shift ratio in malignant lesions. Six of these eight lesions were misclassified on the basis of both attenuation and chemical-shift-ratio values.

CONCLUSION

CT attenuation values are highly correlated with chemical-shift ratios. Both values were indeterminate for a similar subset of benign lesions.

Early switch from intravenous to oral antibiotics and early hospital discharge: a prospective observational study of 200 consecutive patients with community-acquired pneumonia

To determine the proportion of patients who can be treated with early switch to oral antibiotics and early discharge, to evaluate clinical outcome and patient satisfaction for patients treated with early switch and early discharge, and to define the factors that interfere with early discharge for some of the patients who underwent early switch to oral antibiotic therapy.

DESIGN

Prospective study.

PARTICIPANTS

Two hundred consecutive hospitalized patients with community-acquired pneumonia.

MAIN OUTCOME MEASURES

Number of days needed to switch to oral therapy and length of hospital stay. Clinical outcome and satisfaction with care were evaluated for those patients treated with early switch and early discharge.

RESULTS

Early switch to oral antibiotics (within the first 3 days of hospitalization) was performed in 133 patients (67%). Clinical failure was documented in 1 patient. Early switch and early discharge was performed in 88 patients (44%). The mean length of hospital stay for this group was 3.4 days. The most common reason for prolonged hospitalization after the switch to oral antibiotics was the need for diagnostic workup. More than 95% of patients were satisfied with the care they had received.

CONCLUSIONS

Using simple clinical and laboratory criteria, a significant proportion of hospitalized patients with community-acquired pneumonia (44%) can be treated with early switch and early discharge. This model did not affect patient outcome, decreased the length of hospitalization, and was associated with a high level of patient satisfaction.

Central nervous system atypical teratoid rhabdoid tumours: the Canadian Paediatric Brain Tumour Consortium experience

BACKGROUND

Atypical teratoid rhabdoid tumours (ATRT) are aggressive brain tumours mostly occurring in early childhood. Largest published series arise from registries and institutional experiences (1-4). The aim of this report is to provide population-based data to further characterise this rare entity and to delineate prognostic factors.

PATIENTS AND METHODS

A national retrospective study of children ⩽18years diagnosed with a central nervous system (CNS) ATRT between 1995 and 2007 was undertaken. All cases underwent central pathology review.

RESULTS

There were 50 patients (31 males; median age at diagnosis of 16.7months). Twelve patients were >36months. Infratentorial location accounted for 52% of all cases. Nineteen patients (38%) had metastatic disease. Fifteen (30%) underwent gross total resection (GTR). Ten patients (20%) underwent palliation. Among the 40 remaining patients, 22 received conventional chemotherapy and 18 received high dose chemotherapy regimens (HDC); nine received intrathecal chemotherapy and 15 received adjuvant radiation. Thirty of the 40 treated patients relapsed/progressed at a median time of 5.5months (0-32). The median survival time of the entire cohort was 13.5months (1-117.5months). Age, tumour location and metastatic status were not prognostic. Patients with GTR had a better survival (2years overall survival (OS): 60%±12.6 versus 21.7%±8.5, p=0.03). HDC conferred better outcome (2years OS 47.9%±12.1 versus 27.3%±9.5, p=0.036). Upfront radiation did not provide survival benefit. Six of the 12 survivors (50%) did not receive radiation.

CONCLUSION

The outcome of CNS ATRT remains poor. However, the use of HDC provides encouraging results. GTR is a significant prognostic factor. The role of adjuvant radiation remains unclear.

Enhanced release of prostaglandins contributes to flow-induced arteriolar dilation in eNOS knockout mice

Nitric oxide and prostaglandins were shown to contribute to the endothelial mediation of flow-induced dilation of skeletal muscle arterioles of rats. Thus, we hypothesized that flow-induced dilation and its mediation are altered in gracilis muscle arterioles of mice deficient in the gene for endothelial nitric oxide synthase (eNOS-KO) compared with control wild-type (WT) mice. Gracilis muscle arterioles ( approximately 80 micrometer) of male mice were isolated, then cannulated and pressurized in a vessel chamber. The increases in diameter elicited by increases in perfusate flow from 0 to 10 microq/min were similar in arterioles from eNOS-KO (n=28) and WT (n=22) mice ( approximately 20 micrometer at 10 microL/min flow). Removal of the endothelium eliminated flow-induced dilations in vessels of both strains of mice. N(omega)-nitro-L-arginine (L-NNA, 10(-4) mol/L) significantly inhibited flow-induced dilation in arterioles of WT mice by approximately 51% but had no effect on responses of arterioles from eNOS-KO mice. Indomethacin (INDO, 10(-5) mol/L) inhibited flow-induced dilation of WT mice by approximately 49%, whereas it completely abolished this response in arterioles of eNOS-KO mice. Simultaneous administration of INDO and L-NNA eliminated flow-induced responses in arterioles of WT mice. Dilations to carbaprostacyclin were similar at concentrations of 10(-8) and 3x10(-8) mol/L but decreased significantly at 10(-7) mol/L in arterioles of eNOS-KO compared with those of WT mice. These findings demonstrate that, despite the lack of nitric oxide mediation, flow-induced dilation is close to normal in arterioles of eNOS-KO mice because of an enhanced release of endothelial dilator prostaglandins and suggest that this vascular adaptation may contribute to the regulation of peripheral resistance in eNOS-KO mice.

Short-term daily exercise activity enhances endothelial NO synthesis in skeletal muscle arterioles of rats

We aimed to test the hypothesis that as a consequence of short-term daily bouts of exercise the control of arteriolar smooth muscle by endothelium is altered. Rats ran on a treadmill once a day, 5 days/wk, for 2-4 wk (with gradually increasing intensity, up to 26 min at 22 m/min at a 1% grade by the beginning of the 3rd wk and up to 38 min at 28 m/min at a 2% grade by the beginning of the 4th wk) while a control group remained sedentary (SED). Cannulated and pressurized arterioles of rat gracilis muscle developed spontaneous myogenic tone, which was slightly enhanced in exercised (EX) compared with SED rat arterioles. At 80 mmHg pressure, the passive (Ca(2+)-free solution) and active diameters of SED and EX rat arterioles were 105.4 +/- 3.8 and 55.1 +/- 2.3 microns and 107.1 +/- 3.4 and 50.2 +/- 2.2 microns, respectively. Dose-dependent dilations to sodium nitroprusside (10(-8)-10(-6) M) and constrictions to norepinephrine (10(-8)-10(-6) M) were not affected in EX arterioles, whereas dilations to adenosine (10(-6)-10(-4) M) were significantly reduced. In contrast, dose-dependent dilations to acetylcholine (ACh; 5 x 10(-9)-10(-7) M) and L-arginine [precursor of nitric oxide (NO); 10(-4)-10(-3) M] were significantly enhanced (by 33-78 and 57-75%, respectively) in arterioles of EX compared with those of SED rats. Responses of arterioles to sodium nitrite were not different in SED and EX groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Psoriasin (S100A7) expression and invasive breast cancer

Alteration of psoriasin (S100A7) expression has previously been identified in association with the transition from preinvasive to invasive breast cancer. In this study we have examined persistence of psoriasin mRNA and protein expression in relation to prognostic factors in a cohort of 57 invasive breast tumors, comprising 34 invasive ductal carcinomas and 23 other invasive tumor types (lobular, mucinous, medullary, tubular). We first developed an IgY polyclonal chicken antibody and confirmed specificity for psoriasin by Western blot in transfected cells and tumors. The protein was localized by immunohistochemistry predominantly to epithelial cells, with both nuclear and cytoplasmic staining, as well as occasional stromal cells in psoriatic skin and breast tumors; however, in situ hybridization showed that psoriasin mRNA expression was restricted to epithelial cells. In breast tumors, higher levels of psoriasin measured by reverse transcriptase-polymerase chain reaction and Western blot (93% concordance) were significantly associated with estrogen and progesterone receptor-negative status (P < 0.0001, P = 0.0003), and with nodal metastasis in invasive ductal tumors (P = 0. 035), but not with tumor type or grade. Psoriasin expression also correlated with inflammatory infiltrates (all tumors excluding medullary, P = 0.0022). These results suggest that psoriasin may be a marker of aggressive behavior in invasive tumors and are consistent with a function as a chemotactic factor.

Tissue, developmental, and tumor-specific expression of divergent transcripts in Wilms tumor

The Wilms tumor locus on chromosome 11p13 has been mapped to a region defined by overlapping, tumor-specific deletions. Complementary DNA clones representing transcripts of 2.5 (WIT-1) and 3.5 kb (WIT-2) mapping to this region were isolated from a kidney complementary DNA library. Expression of WIT-1 and WIT-2 was restricted to kidney and spleen. RNase protection revealed divergent transcription of WIT-1 and WIT-2, originating from a DNA region of less than 600 bp. Both transcripts were present at high concentrations in fetal kidney and at much reduced amounts in 5-year-old and adult kidneys. Eleven of 12 Wilms tumors classified as histopathologically heterogeneous exhibited absent or reduced expression of WIT-2, whereas only 4 of 14 histopathologically homogeneous tumors showed reduced expression. These data demonstrate a molecular basis for the pathogenetic heterogeneity in Wilms tumorigenesis.

Wilms tumor locus on 11p13 defined by multiple CpG island-associated transcripts

Wilms tumor is an embryonal kidney tumor involving complex pathology and genetics. The Wilms tumor locus on chromosome 11p13 is defined by the region of overlap of constitutional and tumor-associated deletions. Chromosome walking and yeast artificial chromosome (YAC) cloning were used to clone and map 850 kilobases of DNA. Nine CpG islands, constituting a "CpG island archipelago," were identified, including three islands that were not apparent by conventional pulsed-field mapping, and thus were at least partially methylated. Three distinct transcriptional units were found closely associated with a CpG island within the boundaries of a homozygous DNA deletion in a Wilms tumor.

Tissue distribution and therapeutic effect of intravenous free or encapsulated liposomal doxorubicin on human prostate carcinoma xenografts

BACKGROUND

The authors compared the therapeutic effects of doxorubicin in two formulations: free in saline suspension and encapsulated in sterically stabilized liposomes composed of hydrogenated soy phosphatidylcholine/2cholesterol/polyethylene glycol-distearoyl-phosphatidyl-ethanolamine (Doxil, Liposome Technology, Inc., Menlo Park, CA).

METHOD

The drug formulations were injected intravenously to treat human prostate carcinoma PC-3, implanted subcutaneously into nude Swiss mice. Confocal laser scan microscopy and microfluorometry were used to determine tissue distribution and to quantitate drug uptake.

RESULTS

Laser scan microscope and microfluorometer studies showed that the liposome-encapsulated drug entered the liver, the kidneys, and the tumor in greater quantity and remained in the liver and in the tumor longer than the free drug. The liposome formulation produced a 25-fold increase in doxorubicin at the disease site. Doxil was significantly more effective than the free drug in inhibiting growth and in effecting cures and had only minor and temporary systemic toxic effects.

CONCLUSIONS

The current study demonstrated the therapeutic efficacy of doxorubicin, encapsulated in sterically stabilized liposomes, against prostate carcinoma. Decreased systemic elimination, increased penetration into the tumor, and long liposome presence with slow drug release into the tumor probably accounted for the enhanced therapeutic effect of doxorubicin in sterically stabilized liposomes.

FKBP12, the 12-kDa FK506-binding protein, is a physiologic regulator of the cell cycle

FKBP12, the 12-kDa FK506-binding protein, is a ubiquitous abundant protein that acts as a receptor for the immunosuppressant drug FK506, binds tightly to intracellular calcium release channels and to the transforming growth factor beta (TGF-beta) type I receptor. We now demonstrate that cells from FKBP12-deficient (FKBP12(-/-)) mice manifest cell cycle arrest in G(1) phase and that these cells can be rescued by FKBP12 transfection. This arrest is mediated by marked augmentation of p21(WAF1/CIP1) levels, which cannot be further augmented by TGF-beta1. The p21 up-regulation and cell cycle arrest derive from the overactivity of TGF-beta receptor signaling, which is normally inhibited by FKBP12. Cell cycle arrest is prevented by transfection with a dominant-negative TGF-beta receptor construct. TGF-beta receptor signaling to gene expression can be mediated by SMAD, p38, and ERK/MAP kinase (extracellular signal-regulated kinase/mitogen-activated protein kinase) pathways. SMAD signaling is down-regulated in FKBP12(-/-) cells. Inhibition of ERK/MAP kinase fails to affect p21 up-regulation. By contrast, activated phosphorylated p38 is markedly augmented in FKBP12(-/-) cells and the p21 up-regulation is prevented by an inhibitor of p38. Thus, FKBP12 is a physiologic regulator of cell cycle acting by normally down-regulating TGF-beta receptor signaling.

More males seek treatment for eating disorders

OBJECTIVE

This study compares males and females with DSM-IV-defined eating disorders who were admitted to the inpatient eating disorders service at The New York Hospital, Cornell between 1984 and 1987.

METHODS

During this period, 51 males and 693 females presented for their first admission. Demographic information, questionnaires, and SCID interviews were used to compare the male and female samples.

RESULTS

Males were significantly more likely than females to have a later onset of their eating disorder (20.56 vs. 17.15 years), and to be involved in an occupation or sport in which weight control influences performance. There were no significant gender differences in other characteristics or comorbid diagnoses. Males constituted an increasing percentage of total admissions between 1984 and 1997 (r = .692, p = .009).

DISCUSSION

The similarities of core eating disorder psychopathology and comorbid illness in male and female patients encourage the continued use of similar detection and treatment strategies with both groups.