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C Wood

Publications and source records attributed to C Wood.

At least 19 recordsLinked to original sources
PubMed2007

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.

Journal Article↗
PubMed2006

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.

Journal Article↗
PubMed2006

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.

Extraterrestrial Environment↗
PubMed2006

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.

Administration, Rectal↗
PubMed2006

Factors associated with HIV prevalence in a pre-partum cohort of Zambian women.

An ongoing study of mother-to-child human herpes virus-8 (HHV-8) transmission in Zambian women (n = 3160) allowed us to examine the association of medical injections with HIV serostatus while simultaneously accounting for other factors known to be correlated with HIV prevalence. Multi-method data collection included structured interviews, medical record abstraction, clinical examinations, and biological measures. Medically administered intramuscular or intravenous injections in the past five years (but not blood transfusions) were overwhelmingly correlated with HIV prevalence, exceeding the contribution of sexual behaviours in a multivariable logistic regression. Statistically significant associations with HIV also were found for some demographic variables, sexual behaviours, alcohol use, and sexually transmitted diseases (STD). The results confirmed that iatrogenic needle exposure, sexual behaviour, demographic factors, substance use, and STD history are all implicated in Zambian women's HIV+ status. However, the disproportionate association of medical injection history with HIV highlights the need to investigate further and prospectively the role of health-care injection in sub-Saharan Africa's HIV epidemic.

Alcohol Drinking↗
PubMed2005

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.

Atmosphere↗
PubMed2004

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.

Child↗
PubMed2004

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.

Animals↗
PubMed2004

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.

England↗
PubMed2004

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.

Adult↗
PubMed2003

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.

Animals↗
PubMed2002

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.

AIDS-Related Opportunistic Infections↗
PubMed2002

[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.

Anorexia↗
PubMed2002

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.

Adolescent↗
PubMed2001

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.

Adolescent↗
PubMed2001

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.

Antimetabolites, Antineoplastic↗