Tissue-specific regulation of acetyl-CoA carboxylase gene expression by dietary soya protein isolate in rats

We have recently reported that intake of soya protein isolate (SPI) inhibited the DNA-binding activities of hepatic thyroid hormone receptor (TR). The genes for acetyl-CoA carboxylase (ACC), a rate-limiting enzyme in fatty acid synthesis, contain the thyroid hormone response element in their promoters and are regulated by TR. The present study has examined the effect oflong-term feeding of SPI and soya isoflavones (ISF) on the gene expression and protein phosphorylation of different ACC isoforms in different tissues and plasma triacylglycerol (TAG) levels in rats. Sprague-Dawley female rats were fed diets containing 20% casein or alcohol-washed SPI with or without supplemental ISF for 70, 190 and 310d. SPI intake significantly reduced plasma TAG concentrations compared with casein, whereas supplemental ISF had no effect. Hepatic ACCα and ACCβ mRNA abundance and protein content were markedly lowerin the rats fed SPI than in those fed casein. The protein contents of ACCα in the kidneyand ACCβ, the predominant isoform in the heart and kidney, were unchanged by dietary SPI.The ratios of phospho-ACCα/ACCα and phospho-ACCβ/ACCβ were not differentamong dietary groups in all tissues measured. The present study demonstrates that ingestion ofSPI decreases plasma TAG level and down-regulates ACCα and ACCβ gene expression in the liver but not in the heart and kidney. The results indicate that the effect of SPI is tissue-specific and that alteration of ACC gene expression rather than phosphorylation status may play a major role in the regulation of ACC activities by soya proteins.

The lakes of Titan

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.

Dietary soy protein isolate modifies hepatic retinoic acid receptor-beta proteins and inhibits their DNA binding activity in rats

Retinoic acid receptors (RAR) belong to the same nuclear receptor superfamily as thyroid hormone receptors (TR) that were previously shown to be modulated by dietary soy protein isolate (SPI). This study has examined the effect of dietary SPI and isoflavones (ISF) on hepatic RAR gene expression and DNA binding activity. In Expt. 1, Sprague-Dawley rats were fed diets containing 20% casein or 20% alcohol-washed SPI in the absence or presence of increasing amounts of ISF (5-1250 mg/kg diet) for 70, 190, or 310 d. In Expt. 2, weanling Sprague-Dawley rats were fed diets containing 20% casein with or without supplemental ISF (50 mg/kg diet) or increasing amounts of alcohol-washed SPI (5, 10, and 20%) for 90 d. Intake of soy proteins significantly elevated hepatic RARbeta2 protein content dose-dependently compared with a casein diet, whereas supplemental ISF had no consistent effect. Neither RARbeta protein in the other tissues measured nor the other RAR (RARalpha and RARgamma) in the liver were affected by dietary SPI, indicating a tissue and isoform-specific effect of SPI. RARbeta2 mRNA abundances were not different between dietary groups except that its expression was markedly suppressed in male rats fed SPI for 310 d. DNA binding activity of nuclear RARbeta was significantly attenuated and the isoelectric points of RARbeta2 were shifted by dietary SPI. Overall, these results show for the first time, to our knowledge, that dietary soy proteins affect hepatic RARbeta2 protein content and RARbeta DNA binding activity, which may contribute to the suppression of retinoid-induced hypertriglyceridemia by SPI as reported.

Ion channels in sperm motility and capacitation

Spermatozoa depend upon ion channels to rapidly exchange information with the outside world and to fertilise the egg. These efficient ion transporters participate in many of the most important sperm processes, such as motility and capacitation. It is well known that sperm swimming is regulated by [Ca2+]i. In the sea urchin sperm speract, a decapeptide isolated from egg outer envelope, induces changes in intracellular Ca2+ ([Ca2+]i), Na+, cAMP and cGMP, membrane potential (Em) and pH (pHi). Photoactivation of a speract analogue induces Ca2+ fluctuations that generate turns that are followed by straighter swimming paths. A fast component of the [Ca2+], increase that most likely occurs through voltage dependent Ca2+ channels (Ca(v)s) is essential for these turns. The Ca(v)s involved are modulated by the Em changes triggered by speract. On the other hand, mammalian sperm gain the ability to fertilise the egg after undergoing a series of physiological changes in the female tract. This maturational process, known as capacitation, encompasses increases in [Ca2+]i and pHi, as well as an Em hyperpolarization in mouse sperm. Our electrophysiological, immunological and molecular-biological experiments indicate that inwardly rectifying K+ channels regulated by ATP (KATP channels) and epithelial Na+ channels (ENaCs) are functionally present in mouse spermatogenic cells and sperm. Notably, pharmacological experiments indicate that the opening of KATP channels and closure of ENaCs may contribute to the hyperpolarization that accompanies mouse sperm capacitation. Remarkably, both in the sea urchin sperm speract response and in the mouse sperm capacitation, Em hyperpolarization seems necessary to remove inactivation from Ca(v) channels so they can then open.

Molecularly cloned SHIV-1157ipd3N4: a highly replication- competent, mucosally transmissible R5 simian-human immunodeficiency virus encoding HIV clade C Env

Human immunodeficiency virus type 1 (HIV-1) clade C causes >50% of all HIV infections worldwide, and an estimated 90% of all transmissions occur mucosally with R5 strains. A pathogenic R5 simian-human immunodeficiency virus (SHIV) encoding HIV clade C env is highly desirable to evaluate candidate AIDS vaccines in nonhuman primates. To this end, we generated SHIV-1157i, a molecular clone from a Zambian infant isolate that carries HIV clade C env. SHIV-1157i was adapted by serial passage in five monkeys, three of which developed peripheral CD4(+) T-cell depletion. After the first inoculated monkey developed AIDS at week 137 postinoculation, transfer of its infected blood to a naïve animal induced memory T-cell depletion and thrombocytopenia within 3 months in the recipient. In parallel, genomic DNA from the blood donor was amplified to generate the late proviral clone SHIV-1157ipd3. To increase the replicative capacity of SHIV-1157ipd3, an extra NF-kappaB binding site was engineered into its 3' long terminal repeat, giving rise to SHIV-1157ipd3N4. This virus was exclusively R5 tropic and replicated more potently in rhesus peripheral blood mononuclear cells than SHIV-1157ipd3 in the presence of tumor necrosis factor alpha. Rhesus macaques of Indian and Chinese origin were next inoculated intrarectally with SHIV-1157ipd3N4; this virus replicated vigorously in both sets of monkeys. We conclude that SHIV-1157ipd3N4 is a highly replication-competent, mucosally transmissible R5 SHIV that represents a valuable tool to test candidate AIDS vaccines targeting HIV-1 clade C Env.

Nuclear receptors: potential biomarkers for assessing physiological functions of soy proteins and phytoestrogens

Soy consumption is associated with decreased incidence of chronic diseases, including cardiovascular diseases, atherosclerosis, diabetes, osteoporosis, and certain types of cancers. However, consumption of high amounts of soy isoflavones may adversely influence endocrine functions, such as thyroid function and reproductive performance, because of their structural similarity to endogenous estrogens. Nuclear receptors are a group of transcription factors that play critical roles in the regulation of gene expression and physiological functions through direct interaction with target genes. Modulation of the abundance of these receptors, such as changing their gene expression, alters the sensitivity of the target cells or tissues to the stimulation of ligands, and eventually affects the relevant physiological functions, such as growth, development, osteogenesis, immune response, lipogenesis, reproductive process, and anticarcinogenesis. A number of studies have shown that the bioactive components in soy can modify the expression of these receptors in various tissues and cancer cells, which is believed to be a key intracellular mechanism by which soy components affect physiological functions. This review summarizes the current understanding of the modulation of nuclear receptors by soy proteins and isoflavones, and focuses especially on the receptors for estrogens, progesterone, androgen, vitamin D, retinoic acid, and thyroid hormones as well as the potential impact on physiological functions.

A preoperative model evaluating the tissue effects of chemopreventive agents in low-volume prostate cancer

1007

Background: To identify and assess biomarkers modulated by prostate cancer chemopreventive agents, we created a model that, by exploiting the time between histologic diagnosis of prostate cancer and definitive therapy (prostatectomy), expedites tissue cross comparison and confronts the multifocality and multizonal heterogeneity of prostate cancer. Methods: Between February 2001 and April 2002, 48 presurgical patients were enrolled in a single-institution, randomized, double-blind trial of vitamin E (VE) and L-selenomethionine (SeMET) based on the framework of the ongoing Selenium and Vitamin E Cancer Prevention Trial. Patients were treated with 400 IU VE, 200 μg SeMET, a combination of VE and SeMET, or placebo for 3 to 6 weeks before prostatectomy. All patients also received a multivitamin and vitamin C 250 mg each day. Ex vivo simulated sextant biopsies on the radical prostatectomy specimen (RPS) were performed, and 36 of 39 evaluable patients had RPS sections that were suitable for pathologic evaluation. Blood components were collected at baseline and prior to prostatectomy. We derived an apoptotic index (AI) morphologically and a proliferation index (PI) by using immunohistochemistry and counting Ki-67-positive nuclei. Cells were counted and identified by cell type (normal and cancerous) and by zone (peripheral [PZ], transition [TZ], and central [CZ]). Results: In normal epithelial cells when the Wilcoxon rank sum test was used to compare AI and PI changes between groups, the AI was higher in the TZ than in the CZ, a difference independent of treatment effects (p = .01). Between the largest PZ and TZ tumor foci, a statistically significant difference in PI was observed (p = .006). Using a multiple linear regression model fitted for AI from the largest RPS PZ tumor focus, we found a statistically significant difference between the SeMET group and the placebo group (p = .02). Conclusions: Besides introducing new findings, the clinicopathologic model proved itself a platform for biomarker discovery by leveraging molecular technologies to full advantage, including serum protein profiling (Kim et al., CEBP 2005) and gene expression profiling of different cell types. Supported by NIH grant CA88761.

No significant financial relationships to disclose.

Effect of HMG CoA reductase inhibitors on the grade and recurrence of colonic polyps

1016

Background: The burden of treating colon cancer on the healthcare system is huge and screening for colonic polyps has been very effective. Colon cancer arises from colonic polyps in a significant percent of patients and preventive measures to control colonic polyps in the form of dietary interventions, NSAIDS have been looked into. But there are no studies to our knowledge that looked at the effect of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) on colon polyps. The aim of this study was to examine the effect of HMG CoA reductase inhibitors on the grade and recurrence of colonic polyps. Methods: This retrospective case control study included review of the charts of all patients at Geisinger Medical Center who had colonoscopy and polypectomy between 1998 and 2003. These patients were divided into two groups based on the use of HMG CoA reductase inhibitors. A total of 207 patients were identified of which, 60 were in statin group and 147 were in the non-statin group. Logistic regression was used to evaluate the relationships between statin use and 1) recurrence of colonic polyps and, 2) histological grade. Additionally, Cox regression was used to examine the relationship between statin use and time until colonic polyp recurrence. Results: The rate of recurrence of colonic lesions and histological grade at follow-up were not different between the two groups. However, time until recurrence (based on time until 2nd colonoscopy) was longer in the statin group (p=0.001). This association remained after controlling for aspirin use and other characteristics of the patient (p=0.013). Conclusion: Our study suggests that HMG CoA reductase inhibitors might have a role in the secondary prevention of colonic polyps. Larger, prospective randomized studies are needed to validate this finding.

[Table: see text]

No significant financial relationships to disclose.

Titan Radar Mapper observations from Cassini's T3 fly-by

Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be longitudinal dunes. Here we describe this great diversity of landforms. We conclude that much of the surface thus far imaged by radar of the haze-shrouded Titan is very young, with persistent geologic activity.

The Sand Seas of Titan: Cassini RADAR Observations of Longitudinal Dunes

The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show approximately 100-meter ridges consistent with duneforms and reveal flow interactions with underlying hills. The distribution and orientation of the dunes support a model of fluctuating surface winds of approximately 0.5 meter per second resulting from the combination of an eastward flow with a variable tidal wind. The existence of dunes also requires geological processes that create sand-sized (100- to 300-micrometer) particulates and a lack of persistent equatorial surface liquids to act as sand traps.

Challenges in the therapy of secondary hyperparathyroidism

Derangements in mineral metabolism are known to occur early in the course of chronic kidney disease (CKD). Recent clinical practice guidelines are designed to focus on the problem early in the course of kidney disease, when it is recommended to evaluate the levels of parathyroid hormone (PTH) and to try to intervene early if the levels are elevated. To begin early intervention for hyperparathyroidism in chronic kidney disease will require involvement of primary care physicians and other subspecialty groups to identify the patients at risk and begin to intervene with measures to control hyperparathyroidism and its consequences on mineral metabolism. It has recently been demonstrated that chronic kidney disease is a significant risk factor for vitamin D deficiency and since abnormalities in vitamin D metabolism are important in the generation of hyperparathyroidism, this is an issue that needs direct attention. Studies are needed to assess the effects of correcting this vitamin D deficiency in early CKD. As kidney disease progresses, efforts to control hyperparathyroidism will likely need to be intensified and several therapeutic options are available, such as phosphate binders, repletion of vitamin D, the use of active vitamin D sterols, or the use of vitamin D analogs. In addition, it is important to define the appropriate PTH values that need to be achieved to minimize complications on bone. Such studies are in progress at the present time to validate the current more specific PTH assays. Strict guidelines have been proposed for the management of bone and mineral metabolism in patients with CKD stage V on dialysis, and although these challenging recommendations were initially opinion-based, there is mounting evidence which provides confirmation of these targets as relevant. Treatment options for patients on dialysis involve the full spectrum of agents which include phosphate binders, active vitamin D sterols (often given parenterally), the use of calcimimetic agents, surgical parathyroidectomy, and evaluation of appropriate levels of dialysate calcium. Similar to early stages of CKD, studies are in progress to refine the PTH targets with the newer PTH assays. With increased focus on the complications of bone and mineral metabolism as part of the continuum of chronic kidney disease, and with a variety of new therapies available, it is anticipated that improved patient outcomes should be achievable in this patient group.

Soy protein isolate increases hepatic thyroid hormone receptor content and inhibits its binding to target genes in rats

Our previous studies showed that intake of 20% alcohol-washed soy protein isolate (SPI) significantly increased hepatic thyroid hormone receptor (TR) beta1 protein content in rats. However, whether SPI influences the binding ability of TR to its target genes is unknown. The purpose of this study was to examine the effect of increasing amounts of dietary SPI on hepatic TRbeta1 content and the binding of TR to thyroid hormone response element (TRE) in rats. Sprague-Dawley rats (28 d old) were fed diets containing casein (20%) with or without isoflavone supplementation (50 mg/kg diet) or alcohol-washed SPI (5, 10, or 20%) for 90 d. The hepatic TRbeta1 protein content was measured by Western blot, and the binding ability of TR to DNA was examined by electrophoretic mobility shift assay. Consumption of the 20% SPI diet increased pancreatic relative weight and decreased spleen relative weight. Intake of SPI markedly elevated TRbeta1 content in both male and female rats compared with a casein-based control diet. The increase in TRbeta1 in females was much higher than that in males. Interestingly, the binding abilities of TR to DNA were significantly inhibited by increasing amounts of dietary SPI in female rats. In conclusion, this study shows for the first time that dietary SPI increases hepatic TRbeta1 protein content and inhibits the binding of TR to target genes. Modulation of hepatic TRbeta1, a key regulator of gene expression involved in lipid metabolism, by SPI may be a novel mechanism by which soy components lower blood lipid level and exert their hypocholesterolemic actions.

Cassini Radar Views the Surface of Titan

The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of approximately 0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons.

Self-assessment of immediate post-vaccination pain after two different MMR vaccines administered as a second dose in 4- to 6-year-old children

The aim of this study was to compare self-reported immediate post-vaccination pain and safety of Priorix versus RORVax in 4- to 6-year-old children receiving their second dose of MMR vaccine, using the Faces Pain Scale-Revised (FPS-R), a validated self-report pain scale recommended by the French National Accreditation Agency and Health Evaluation. A total of 620 children from 28 French pediatricians completed all study procedures. Immediate post-vaccination pain was reported by 17.8% of the subjects in Priorix group (N=309) and by 44.7% of the subjects in RORVax group (N=311) [OR=3.7; P<0.001]. Parents' pain scores correlated significantly with children's scores. The reduction of immediate pain incidence in Priorix group persisted over the 4 post-vaccination days. This study, using a validated self-assessment pain scale, confirmed previous data showing a significantly lower incidence of immediate post-vaccination pain with Priorix as compared to RORVax.

Preserved antigenicity of HIV-1 p24 produced and purified in high yields from plants inoculated with a tobacco mosaic virus (TMV)-derived vector

Production of structural proteins from foot-and-mouth disease virus (FMDV) and bovine herpes virus (BHV-1) in Nicotiana benthamiana through the use of a tobacco mosaic virus-based vector (TMV-30B) has been reported previously. The development of the TMV-30B-HISc vector, a new version that adds a C-terminal histidine (His) sequence to the foreign protein expressed is described. Coding sequences from the FMDV VPl protein and the core protein, p24, from a clade C HIV-1 isolate from Zambia were cloned into the new vector and infective RNAs were generated for each construct to inoculate N. benthamiana plants. His-tagged proteins were purified from inoculated leaves using immobilized metal affinity chromatography (IMAC) as detected by Coomassie blue staining and proteins were further characterized in Western blot assays using a commercial anti-6xHis mAb and specific polyclonal antisera for each protein. While yields obtained for the VPl-His protein after purification were similar to those in crude extracts obtained with the previous TMV-VPl vector, p24-His yields were 10-15 times higher than those of VPl-His. Twenty-five grams of TMV-p24-HISc inoculated leaves were processed to obtain 2.5 mg of isolated p24-His and the recombinant protein was inoculated in rabbits to test immunogenicity and antigenic integrity of the plant-produced p24-His. Animals developed a strong and specific humoral response to the p24-His after the first booster and immune sera was able to recognize the native p24 from a different clade expressed on the surface of the HIV-1 chronically infected HUT78/ARV T-cell line. Importantly, the recombinant p24-His proved its efficiency by confirming the serology of 117 samples previously tested by two rapid HIV-1 tests, thus representing an excellent alternative for production of highly specific diagnostic reagents for HIV endemic regions in the developing world.

Perinatal transport: problems in neonatal intensive care capacity

OBJECTIVE

To assess the quantity and nature of transfers within the Yorkshire perinatal service, with the aim of identifying suitable outcome measures for the assessment of future service improvements.

DESIGN/SETTING

Collection of data on perinatal transfers from all neonatal and maternity units located in the Yorkshire region of the United Kingdom from May to November 2000.

PATIENTS

Expectant mothers (in utero transfers) and neonates (ex utero transfers).

INTERVENTIONS

None

MAIN OUTCOME MEASURES

Quantification of in utero and ex utero transfers; the reasons for and resources required to support transfers; the nature of each transfer (acute, specialist, non-acute, into or out of region).

RESULTS

In the period studied, there were 800 transfers (337 in utero; 463 ex utero); 306 transfers were "acute" (80% of transfers in utero), 214 because of specialist need, and 280 "non-acute". Some 37% of capacity transfers occurred from the two level 3 units in the region. Of 254 transfers out of the 14 neonatal units for intensive care, 44 (17.3%) were transferred to hospitals outside the normal neonatal commissioning boundaries.

CONCLUSIONS

The study highlights a continuing apparent lack of capacity within the neonatal service in the Yorkshire region, resulting in considerable numbers of neonatal and maternal transfers.

Waiting times for treatment of rectal cancer in North West England

An interim goal of the NHS National Cancer Plan is that, by 2005, patients with cancer should be treated within one month of diagnosis and within two months from urgent general practitioner referral. Preoperative radiotherapy for rectal cancer reduces the risk of local recurrence and may translate into improved patient survival. We conducted a prospective audit of existing waiting times for preoperative radiotherapy experienced by 65 patients with rectal cancer referred to the Christie Cancer Centre, Manchester, UK, between May and November 2002. The median time between referral from the surgeon to the start of radiotherapy was 40 days (range 11-85). Only 4 patients (6%) received radiotherapy within 28 days of referral by the surgeon. 62 patients (95%) underwent surgery within 14 days of completing radiotherapy. Delays in the provision of preoperative radiotherapy were primarily due to shortages of radiography staff and equipment. Lack of such infrastructure will prove a major stumbling block to achieving the targets of the NHS Cancer Plan.

Increased iron absorption in lemurs: Quantitative screening and assessment of dietary prevention

Iron storage disease (ISD) in lemurs has been reported since as early as the 1960s, and in the 1980s was demonstrated to be a consistent finding in postmortem investigations of captive lemurs. Since then this disease has consistently been diagnosed at the point of necropsy. In the current study we describe a preclinical screening procedure, as well as the quantified preventive effects of dietary intervention upon iron absorption. Twenty-three individual lemurs of four species were initially tested with the transferrin saturation test (%TS); 21 of these animals were on conventional zoo diets, and two were fed a specific diabetic diet. Initially, 20 of 21 lemurs on conventional zoo diets were demonstrated to have %TS levels above the normal range for humans; 17 of these lemurs were in the category (for humans) of excessive iron absorption. A dietary change aimed at reducing dietary iron and vitamin C levels and increasing the levels of iron-chelating tannins and/or phytates was instigated. After the animals were retested, a matched-pair comparison of %TS values before and after the diet change revealed significantly (P=0.038, n=7) lower %TS values after the diet change. All species averages were in the human hyperabsorption range on conventional zoo diets (n=21). No species averages were in that range after the dietary change (n=18). The results indicate that further investigations into the use of %TS testing in lemur husbandry, and specific preventive dietary measures, should be conducted.

Borderline tuberculoid leprosy: an immune reconstitution phenomenon in a human immunodeficiency virus-infected person

Two months after starting highly active antiretroviral treatment (HAART), an individual with human immunodeficiency virus type 1 (HIV-1) infection and profound CD4+ T lymphocytopenia developed several erythematous plaques on his face, which were due to borderline tuberculoid leprosy with reversal reaction. The temporal association between the development of these lesions and changes in blood CD4+ lymphocyte count and plasma HIV-1 load observed during HAART strongly suggests that the presentation of leprosy resulted from immune reconstitution.

[Treatment of non-painful symptoms in terminally ill children]

The care of children at the end of life is gradually improving. Nevertheless, more than half suffer from intractable symptoms before dying. Although pain has been the subject of clinical research, evidence-based data are almost completely lacking for other symptoms, highlighting the need for clinical research in palliative care. We review the available evidence on fatigue, anorexia, dyspnea, respiratory secretions, cough, constipation, mouth dryness, urinary obstruction, terminal convulsions and gasping. When evidence is lacking, we offer our empiric approach. Short duration benzodiazepines have become an important component of treatment that should remain simple, while providing the dying child the comfort needed to experience the highest quality relationships with those around him.

Development of symptoms of tobacco dependence in youths: 30 month follow up data from the DANDY study

OBJECTIVE

To determine if there is a minimum duration, frequency or quantity of tobacco use required to develop symptoms of dependence.

DESIGN AND SETTING

A retrospective/prospective longitudinal study of the natural history of tobacco dependence employing individual interviews conducted three times annually in two urban school systems over 30 months. Detailed histories of tobacco use were obtained including dates, duration, frequency, quantity, patterns of use, types of tobacco, and symptoms of dependence.

PARTICIPANTS

A cohort of 679 seventh grade students (age 12-13 years).

MAIN OUTCOME MEASURES

The report of any of 11 symptoms of dependence.

RESULTS

Among 332 subjects who had used tobacco, 40% reported symptoms, with a median latency from the onset of monthly smoking of 21 days for girls and 183 days for boys. The median frequency of use at the onset of symptoms was two cigarettes, one day per week. The report of one or more symptoms predicted continued smoking through the end of follow up (odds ratio (OR) 44, 95% confidence interval (CI) 17 to 114, p < 0.001).

CONCLUSIONS

Symptoms of tobacco dependence commonly develop rapidly after the onset of intermittent smoking, although individuals differ widely in this regard. Girls tend to develop symptoms faster. There does not appear to be a minimum nicotine dose or duration of use as a prerequisite for symptoms to appear. The development of a single symptom strongly predicted continued use, supporting the theory that the loss of autonomy over tobacco use begins with the first symptom of dependence.

Embryo splitting: a role in infertility?

Embryo splitting may be used to increase the potential fertility of couples requiring IVF. Using cattle as a model, it is possible to increase pregnancy rates from 70% per transfer of good quality in-vivo-produced embryos, to 110% by transferring the two demi-embryos resulting from the bisection of one embryo. The 30-40% greater chance of conception would reduce costs for the government, health authorities and patients, and reduce stress, time and complications for women having IVF treatment. Embryo splitting may also provide donor embryos for infertile couples that cannot conceive naturally or with IVF. The shortage of children for adoption and donor embryos may be overcome by the production of demi-embryos.

Identification of a cellular protein that interacts and synergizes with the RTA (ORF50) protein of Kaposi's sarcoma-associated herpesvirus in transcriptional activation

Lytic reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8, from latency requires transcriptional transactivation by the viral protein RTA encoded by the ORF50 gene. Very little is known about how RTA functions and the cellular factors that may be involved in its transactivation function. Using the yeast two-hybrid system, we have identified a human cellular protein that can interact with KSHV RTA. The cellular protein, referred to as the human hypothetical protein MGC2663 by GenBank, is encoded by human chromosome 19. This protein is 554 amino acids (aa) in size and displays sequence similarity with members of the Krueppel-associated box-zinc finger proteins (KRAB-ZFPs). MGC2663 expression could be detected in all primate cell lines tested, and its expression level was neither stimulated nor inhibited by RTA. MGC2663 specifically synergizes with RTA to activate viral transcription, and overexpression of MGC2663 in the presence of RTA further enhances RTA transactivation of several viral promoters that were identified as targets for RTA. Coimmunoprecipitation and pull-down assays further demonstrated that MGC2663 interacts with RTA both in vivo and in vitro, and the N-terminal 273 aa of KSHV RTA and the potential zinc finger domain of MGC2663 are required for their interaction. Our results indicate that this novel human cellular protein, MGC2663, named K-RBP (KSHV RTA binding protein) due to its RTA binding feature, specifically interacts with the KSHV RTA protein and functions as a cellular RTA cofactor to activate viral gene expression. Though its normal cellular function needs to be further studied, K-RBP may play a significant role in mediating RTA transactivation in vivo.

Restoration of reproductive potential following expiration or removal of melengestrol acetate contraceptive implants in golden lion tamarins (Leontopithecus rosalia)

Although reversible contraception is important to successful management of small populations, there are concerns about the reversibility of melengestrol acetate (MGA), the most commonly used implant in captive animals. Female golden lion tamarins (Leontopithecus rosalia) placed in potential breeding situations after surgical MGA implant removal showed a 75% return to reproduction within 2 yr, unlike golden-headed tamarins (Leontopithecus chrysomelas), which have had a 29% return to reproduction following implant removal. This rate was indistinguishable from the breeding probability for newly formed pairs involving nonimplanted females. Litter size, stillbirth rate, and infant survival rate were not significantly different between nonimplanted and implant-removed female golden lion tamarins. However, females with implants left in (and assumed to have expired) showed higher stillbirth and infant mortality rates than did females with implants removed. For seven female golden lion tamarins for which reproductive histories before and after MGA implantation were available, litter size was unaffected by MGA implantation and subsequent removal. Infant survival rate for these females appeared to be lower after removal but was indistinguishable from rates in the nonimplanted females. Prior reproductive experience, length of time with an implant, and age of the females did not affect the probability of breeding for females after removal of the implants. Overall, breeding probability of nonimplanted females declined with age. Although the results of this study confirm the reversibility of MGA implants in golden lion tamarins, there appear to be some effects on viability of offspring, particularly offspring born to females with implants left in and presumed expired.

Vertical transmission of Kaposi's sarcoma-associated herpesvirus

Little is presently known about the specific routes of transmission of Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain the most likely means of KSHV transmission.

How many inpatients at an acute hospital have palliative care needs? Comparing the perspectives of medical and nursing staff

The primary aim of this prospective face-to-face interview survey was to identify the proportion of inpatients at an acute hospital (Royal Hallamshire Hospital, Sheffield, UK) considered to have palliative care needs by medical and nursing staff directly responsible for their care. During the 1-week period of the survey (6-10 September 1999), 452 inpatients were present in the hospital. Nursing staff were interviewed for 99% of patients; medical staff for 81%. Staff interview data were supplemented by case note review. Overall, 23% of the total inpatient population were identified as having palliative care needs and/or being terminally ill by staff and 11% were considered suitable for referral to a specialist palliative care bed. However, there was a low level of concurrence between medical and nursing staff as to which individual patients had palliative care needs (although this increased with perceived increased proximity to death), including which would be suitable for referral to a specialist palliative care bed. A need for further palliative care education for medical and nursing staff working within acute hospital settings was identified to ensure that the best use is made of hospital-based specialist palliative care services.

Cortisol effects on aerobic and anaerobic metabolism, nitrogen excretion, and whole-body composition in juvenile rainbow trout

The influence of chronic cortisol elevation on metabolism, body composition, and fuel use patterns was examined in juvenile rainbow trout (Oncorhynchus mykiss). Measurements were performed in a control group (day 0) and in two experimental groups at days 3, 10, and 30 after treatment with a cortisol implant or a sham implant. All fish were fed 1% daily ration. Measured plasma cortisol levels were highest at day 3 and returned close to normal values by day 30 in cortisol-implanted fish. No plasma cortisol elevation was observed in the sham group. Growth was depressed in the cortisol-treated fish. Cortisol elevation resulted in increased plasma glucose concentrations during the entire experimental period, elevated CO2 production at day 3 and 30, and an elevated respiratory quotient (RQ) exceeding 1.0 on these days. Nitrogen excretion, estimated as the sum of ammonia-N plus urea-N excretion, and the nitrogen quotient exhibited small decreases at day 30. Total-N excretion, measured with a nitrogen oxidizer, was approximately twice the sum of ammonia-N plus urea-N excretion but exhibited a similar trend. Aerobic metabolism (routine O2 consumption) was higher on day 10 compared to sham-implanted fish, although not relative to day 0 control levels. Anaerobic metabolism increased substantially, as evidenced by pronounced plasma lactate elevations at days 3 and 10, a small increase in whole-body lactate on day 10, and the elevated RQ on days 3 and 30. Body composition exhibited an increase in total carbohydrate at days 3 and 10, mainly reflecting increased glycogen levels. Protein concentration was stable, indicating, in accord with the respirometry data, that protein usage did not fuel the increased metabolism or carbohydrate elevation. Redirection of nutrient uptake from food and/or mobilization of lipid stores (which decreased relative to the control group but not relative to shams) are suggested as possible energy sources for these actions of cortisol.

Induction of a TRAIL-mediated suicide program by interferon alpha in primary effusion lymphoma

Gammaherpes viruses are often detected in lymphomas arising in immunocompromised patients. We have found that Azidothymidine (AZT) alone induces apoptosis in Epstein Barr Virus (EBV) positive Burkitt's lymphoma (BL) cells but requires interferon alpha (IFN-alpha) to induce apoptosis in Human Herpes Virus Type 8 (HHV-8) positive Primary Effusion Lymphomas (PEL). Our analysis of a series of AIDS lymphomas revealed that IFN-alpha selectively induced very high levels of the Death Receptor (DR) tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in HHV-8 positive PEL lines and primary tumor cells whereas little or no induction was observed in primary EBV+ AIDS lymphomas and EBV-Burkitt's lines. AZT and IFN-alpha mediated apoptosis in PEL was blocked by stable overexpression of dominant negative Fas Associated Death Domain (FADD), decoy receptor 2 (DcR2), soluble TRAIL receptor fusion proteins (DR-4 and DR-5) and thymidine. Trimeric TRAIL (in place of IFN-alpha) similarly synergized with AZT to induce apoptosis in HHV-8 positive PEL cells. This is the first demonstration that IFN-alpha induces functional TRAIL in a malignancy that can be exploited to effect a suicide program. This novel antiviral approach to Primary Effusion lymphomas is targeted and may represent a highly effective and relatively non-toxic therapy.