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Biomedical subjects

J Jones

Publications and source records attributed to J Jones.

At least 55 records · Page 3Linked to original sources
PubMed2004

Female preponderance in congenital adrenal hyperplasia due to CYP21 deficiency in England: implications for neonatal screening.

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase (CYP21) deficiency causes symptoms ranging from life-threatening neonatal adrenal crises to minimal virilization in adulthood. The relationship between CYP21 genotype and phenotypic markers in a non-screened population of 73 CAH children (44 female, 29 male; 54 white, 19 Asian) treated at the Royal Manchester Children's Hospital was investigated and ethnic and sex differences assessed. The patients were categorized according to the mutation on the mildest allele. The age at the time of diagnosis differed significantly between the groups (p = 0.02): all 25 Null and 25 of 26 of the I2 splice patients were diagnosed during the neonatal period, whereas 7 of 11 I172N patients were diagnosed late. Degree of female genital virilization, 17-hydroxyprogesterone level at diagnosis, and fludrocortisone requirement during the 1st year of treatment correlated with the genotype, although Asian Null patients required more fludrocortisone than their white counterparts (p = 0.055). There was an equal sex ratio in both the I2 splice (12 female/14 male) and I172N (5 female/6 male) groups. However, in the Null group, the ratio was 4.0 (20 female/5 male; p = 0.003), suggesting that some Null male infants perish before being clinically detected to have CYP21 deficiency. Our findings strongly support the need for implementation of a neonatal screening programme for CAH in the UK which may reduce the male infant mortality.

Adrenal Hyperplasia, Congenital↗
PubMed2004

In vitro directed differentiation of mouse embryonic stem cells into insulin-producing cells.

AIMS/HYPOTHESIS: We recently demonstrated that insulin-producing cells derived from embryonic stem cells normalise hyperglycaemia in transplanted diabetic mice. The differentiation and selection procedure, however, was successful in less than 5% of the assays performed. Thus, to improve its effectiveness, new strategies have been developed, which increase the number of islet cells or islet progenitors. METHODS: Mouse embryonic stem cells transfected with a plasmid containing the Nkx6.1 promoter gene followed by a neomycin-resistance gene, were cultured with factors known to participate in endocrine pancreatic development and factors that modulate signalling pathways involved in these processes. Neomycin was used to select the Nkx6.1-positive cells, which also express insulin. The transfected cells were differentiated using several exogenous agents, followed by selection of Nkx6.1-positive cells. The resulting cells were analysed for pancreatic gene and protein expression by immunocytochemistry, RT-PCR and radioimmunoassay. Also, proliferation assays were performed, as well as transplantation to streptozotocin-induced diabetic mice. RESULTS: The protocols yielded cell cultures with approximately 20% of cells co-expressing insulin and Pdx-1. Cell trapping selection yielded an almost pure population of insulin-positive cells, which expressed the beta cell genes/proteins Pdx-1, Nkx6.1, insulin, glucokinase, GLUT-2 and Sur-1. Subsequent transplantation to streptozotocin-induced diabetic mice normalised their glycaemia during the time period of experimentation, proving the efficiency of the protocols. CONCLUSIONS/INTERPRETATION: These methods were both highly efficient and very reproducible, resulting in a new strategy to obtain insulin-containing cells from stem cells with a near 100% success rate, while actively promoting the maturation of the exocytotic machinery.

Animals↗
PubMed2004

The nature and course of neuropsychological morbidity in chronic temporal lobe epilepsy.

OBJECTIVE: To characterize the nature and degree of cognitive morbidity in patients with chronic temporal lobe epilepsy compared with healthy control subjects, determine the association between the duration of epilepsy and cognitive morbidity, and ascertain whether there are factors that moderate the association between duration of disorder and cognitive impairment. METHODS: Temporal lobe epilepsy (n = 96) and healthy control (n = 82) subjects were assessed with a comprehensive neuropsychological battery. Test performances were adjusted for age, gender, and education and transformed to a common metric (z scores). Analyses included group comparisons and correlations of duration of epilepsy with cognitive morbidity. RESULTS: Patients with temporal lobe epilepsy exhibited not only worse memory function (p < 0.05) but worse performance across measures of intelligence, language, executive function, and motor speed (p < 0.05). Chronicity of epilepsy was related to worsening mental status (r = 0.42, p < 0.001). This relationship was particularly evident among those individuals with less (r = 0.58, p < 0.001) compared with more (r = 0.25, NS) cerebral reserve, operationally defined by years of formal education. CONCLUSIONS: Neuropsychological morbidity in chronic temporal lobe epilepsy is widespread in nature despite a focal epileptic process. Cross-sectional analyses demonstrate that increasing duration of epilepsy is associated with worsening mental status. Individuals with less educational attainment (low cerebral reserve) exhibit especially poor cognitive function in association with chronicity of epilepsy.

Adolescent↗
PubMed2004

Hypoketotic hypofattyacidaemic hypoinsulinaemic hypoglycaemia in a child with hemihypertrophy? A new syndrome.

BACKGROUND: Recurrent and persistent hypoketotic, hypofattyacidaemic hypoglycaemia in infancy and childhood is most frequently due to hyperinsulinism of infancy. This biochemical profile can also be due to non-islet cell tumour hypoglycaemia or circulating insulin-receptor autoantibodies. Hyperinsulinaemic hypoglycaemia is also seen in children with the Beckwith-Wiedemann syndrome, where it is usually transient. METHODS/RESULTS: We report a novel case of child with hemihypertrophy and severe persistent hypoketotic, hypofattyacidaemic hypoinsulinaemic hypoglycaemia. No 'big' pro-IGF2 forms or circulating insulin-receptor antibodies were found. Glucose and protein isotope turnover studies showed marked suppression of hepatic glucose production during fasting. There was no evidence for constitutive autophosphorylation of the insulin or IGF-1 receptor, and no evidence for up-regulation of IGF-1 receptor. CONCLUSION: The precise pathophysiology of this novel case is still unclear.

Abnormalities, Multiple↗
PubMed2004

The public health response to a case of Lassa fever in London in 2000.

OBJECTIVES: Evaluation of the Department of Health 1996 guidance, the Memorandum on the Management and Control of Viral Haemorrhagic Fevers. METHODS: Description of the public health management in 2000 of the fifth UK patient confirmed to have Lassa fever. RESULTS: Delayed risk categorisation of the patient occurred for a variety of reasons. DH Guidance was followed once infection control advice was sought. Active surveillance of 125 contacts was extremely resource intense, involving over 3000 communications. Self-monitoring by healthcare workers should be considered in future. Advice on use of ribavirin prophylaxis is not included in the Memorandum, nor advice or templates for information sheets for contacts. Information sheets are now available from the Health Protection Agency in the event of future cases. International aspects not adequately addressed include the need for reliable risk assessment to be carried out before patients are medically evacuated from the country of origin, and the steps required to repatriate UK nationals. Effective and efficient communication is required between national and international organisations involved in such incidents. CONCLUSIONS: If guidelines are unclear or impracticable they will not be followed. It is important that lessons are learned and documented and that national guidance be regularly reviewed.

Communicable Disease Control↗
PubMed2004

Measurement of Vitamin D metabolites: an international perspective on methodology and clinical interpretation.

The International Quality Assessment Scheme for Vitamin D metabolites (DEQAS) was introduced in 1989. Initially, the aim was to improve the reliability of 25-hydroxyvitamin D (25-OHD) assays but the scheme was extended in 1997 to include 1,25-dihydroxyvitamin D (1,25(OH)(2)D). DEQAS has 95 members in 18 countries (January 2003). Five serum samples are distributed quarterly and participants are given up to 6 weeks to return their results for statistical analysis. The majority of participants use commercial kits for both analytes. A performance target was set by an advisory panel in 1997 and, at present, requires participants to get 80% or more of their results within +/-30% of the All-Laboratory Trimmed Mean (ALTM). The performance targets are under continual review. In 2003, 59% of participants met the target (cf. 52% in 2000). A questionnaire, distributed in January 2003, requested information on methods and the interpretation of results. Reference ranges varied but there was reasonable agreement on the 25-OHD concentrations below which Vitamin D supplementation was advised. A minority (22%) of respondents was unsure whether Vitamin D(3) or Vitamin D(2) was used to treat patients in their locality. The majority (52%) of assays for 1,25(OH)(2)D were done 'on demand' and others for apparently spurious reasons. Most respondents thought participation in DEQAS extremely important and the planned introduction of on-line reporting should enhance its value.

Humans↗
PubMed2004

A double-blind, placebo-controlled, randomized study to evaluate the efficacy, safety and tolerability of tegaserod in patients with irritable bowel syndrome.

BACKGROUND: Tegaserod has been shown to be an effective therapy for the multiple symptoms of irritable bowel syndrome (IBS) in Western and Asia-Pacific populations. This study evaluated the efficacy, safety and tolerability of tegaserod versus placebo in patients with IBS. METHODS: Patients with IBS (excluding those whose primary bowel symptom was diarrhoea) were randomized to receive either tegaserod 6 mg b.i.d. (n = 327) or placebo (n = 320) for a 12-week double-blind treatment period. The primary efficacy variable (over weeks 1 to 4) was the response to the question: 'Over the past week do you consider that you have had satisfactory relief from your IBS symptoms?' Secondary efficacy variables assessed overall satisfactory relief over 12 weeks and the individual IBS symptoms. RESULTS: Overall satisfactory relief was greater in the tegaserod group than in the placebo group. Over weeks I to 4, the odds ratio was 1.54, that is, the odds of satisfactory relief were 54% higher in the tegaserod group than in the placebo group (95% confidence interval for odds ratio (CI) (1.14, 2.08), P = 0.0049). Over weeks 1 to 12, the odds ratio was 1.78, that is, the odds of satisfactory relief were 78% higher in the tegaserod group than in the placebo group (95% CI (1.35, 2.34), P < 0.0001). A statistically significant therapeutic gain over placebo was observed for the majority of weeks from week 1 to week 12 (except weeks I and 4), with a mean therapeutic gain of 7.3 and 10.6 percentage points over weeks 1-4 and weeks 1-12, respectively. Headache was the most commonly reported adverse event (8.0% tegaserod versus 4.7% placebo). Diarrhoea was reported by 9.2% of patients on tegaserod (1.3% on placebo) and led to discontinuation in 2.8% of tegaserod patients. CONCLUSION: Tegaserod 6 mg b.i.d. is an effective, safe and well-tolerated treatment in patients suffering from IBS without diarrhoea as primary bowel symptom.

Adolescent↗
PubMed2004

Insulin resistance and pre-eclampsia: a role for tumor necrosis factor-alpha?

Insulin resistance occurs in pre-eclampsia, but the cause is unknown. Furthermore, it is uncertain whether women destined to develop pre-eclampsia have a pre-existing insulin resistance or whether it is acquired with the development of the disease. We carried out this study to test the hypotheses that the increase in insulin resistance associated with pre-eclampsia is related to higher levels of tumor necrosis factor (TNF)-alpha, and that the increase in insulin resistance precedes the clinical onset of the disease. Fasting plasma samples were obtained from ten women who subsequently developed pre-eclampsia and ten normal pregnant controls at 16, 20, 24, 28, 32 and 36 weeks' gestation to measure circulating levels of insulin, glucose and TNF-alpha. Fasting insulin resistance index (FIRI) was calculated from insulin and glucose concentrations. In the normal controls, fasting insulin and TNF-alpha levels, and FIRI increased with gestation, and these were significantly greater than baseline values from 24, 28 and 28 weeks, respectively. In the group of women who developed pre-eclampsia, plasma levels of insulin and the FIRI were significantly higher than baseline from 20 and 24 weeks, respectively, but both were significantly higher than in the control group at 32 and 36 weeks. The increase in TNF-alpha in the pre-eclampsia group was significantly greater than in normal pregnant controls (p < 0.001). However, there was no significant association between TNF-alpha levels and FIRI in either normal pregnancy or pregnancies developing pre-eclampsia. These data suggest that insulin resistance in pre-eclampsia precedes the clinical onset of the disease, but that it is not related to elevated levels of TNF-alpha.

Adult↗
PubMed2004

Macaque dendritic cells infected with SIV-recombinant canarypox ex vivo induce SIV-specific immune responses in vivo.

Dendritic cells (DCs) infected with recombinant avipox vectors express the introduced genes and activate antigen-specific T cells. DCs exhibit distinct differentiation-dependent immune functions. Moreover, immature DCs are readily infected by canarypox vectors, but undergo tumor necrosis factor (TNF)-alpha-dependent death, while fewer mature DCs get infected and resist dying. A pilot study was performed using the rhesus macaque system to explore whether immature and mature DCs infected with SIV-recombinant canarypox (vCP180) ex vivo could induce primary virus-specific immune responses in vivo. After subcutaneous (sc) reinjection, functional monocyte-derived DCs migrated to lymph nodes (LNs) within 1-2 days and primed T cells in vivo. This was observed by monitoring dye-labeled DCs in the draining LNs and tetanus toxoid (TT)-specific T cell responses after injection of TT-loaded DCs. DCs from simian immunodeficiency virus (SIV)-naïve rhesus macaques were infected with vCP180 (SIVmac142 gag, pol, and env genes), and sc reinjected into donor animals. Low-level SIV-specific T cell proliferation, but little if any interferon (IFN)-gamma production was detected. DCs pulsed with vCP180 in combination with TT and keyhole limpet hemocyanin (KLH) (to activate additional T cells and provide "helper" cytokines) induced SIV-, TT-, and KLH-specific T cell responses, including IFN-gamma responses not seen when vCP180-carrying DCs were used alone. Interleukin (IL)-10 and low-level antibody responses were also observed. This pilot study provides the proof of principle that sc injected ex vivo SIV-recombinant canarypox-infected DCs safely induce low-level SIV-specific immune responses in vivo.

Animals↗
PubMed2004

Development of an anti-Salmonella typhi Vi ELISA: assessment of immunocompetence in healthy donors.

We have developed a solid-phase enzyme-linked immunosorbent assay (ELISA) to study the vaccination responses to Vi capsular polysaccharide of Salmonella typhi (S. typhi Vi) vaccine. Purified S. typhi Vi polysaccharide was biotinylated and bound to streptavidin coated microtitre plates. Reproducibility was determined across a range of IgG antibody levels: mean interassay coefficients of variation (CVs) were <11.9% for non-vaccinated sera with low levels and <11.1% for sera with very high levels of anti-S. typhi Vi IgG. Specificity was assessed by inhibition studies using salmonella antigen. We have developed the ELISA based on normal adult serum responses to test immunization with S. typhi Vi vaccine. We also report here anti-S. typhi Vi IgG levels in a group of healthy preschool children. In non-vaccinated adult sera (n = 104), the median value of anti-S. typhi Vi IgG, expressed in S. typhi Vi arbitrary units (AU/ml), was 5.3 AU/ml and in non-vaccinated sera from children (n = 44) the median value was 1.4 AU/ml. The data from immunization of healthy volunteers (n = 23) show that geometric mean levels of anti-S. typhi Vi IgG were significantly higher (P < 0.0001) for post-vaccination subjects (39.2 AU/ml) compared to paired prevaccination (3.9 AU/ml) values. A total of 21/23 vaccine recipients had <8 AU/ml S. typhi Vi IgG in their sera prior to vaccination and of these 20/21 (95%) exhibited threefold increases and 14/21 (67%) fourfold increases in their S. typhi Vi IgG following vaccination. Based on the data in this study, we propose a threefold increase in anti-S. typhi Vi IgG post-vaccination to be considered a positive vaccination response. The ability to demonstrate clearly an antibody rise in response to immunization with S. typhi Vi capsular polysaccharide vaccine suggests that this is likely to be a useful vaccine for the assessment of B cell function in patients with suspected immune deficiency.

Adult↗
PubMed2004

Cross-cultural working in community learning disabilities services: clinical issues, dilemmas and tensions.

BACKGROUND: People with learning disabilities from minority ethnic communities face many layers of disadvantage. Providing services that are culturally appropriate and sensitive can be difficult. METHOD: Through the use of clinical examples the issues, tensions and dilemmas raised for a community learning disabilities team in attempting to provide culturally sensitive services in an increasingly multicultural environment are discussed. Ways in which good practice can be more closely achieved are debated. CONCLUSIONS: Conflicts between the principal service values of individuality, choice, promotion of mental health and normalization, whilst also respecting the beliefs and values of other religions and cultures, can raise tensions and dilemmas for learning disabilities services. The importance of sensitive and appropriate service configuration, sharing of good practice, and good staff training are emphasized.

Adult↗
PubMed2004

Favourable outcome for patients with myeloid disorders treated with fludarabine-melphalan reduced-intensity conditioning and allogeneic bone marrow stem cell transplantation without the use of T-lymphocyte-depleting antibodies.

We report the use of reduced-intensity conditioning (RIC)-matched sibling allogeneic bone marrow stem cell transplantation as a method of establishing a graft-vs.-leukaemia (GvL) effect against myeloid disorders using a fludarabine-melphalan protocol without the use of T-lymphocyte-depleting antibodies. The 16 patients in this group had predominantly poor-risk acute myeloid leukaemia (AML) (n=10), AML/myelodysplasia (MDS) (n=2) and MDS (n=4). All but one patient achieved full haematopoietic engraftment. Thirteen of 16 patients are alive and in continued complete remission on completion of this study with a median follow-up of 426 d (range 83-1524). The actuarial 4 yr disease-free and overall survival is 79% for both. Only one patient relapsed following transplant, giving a relapse rate of 6% during the study period. The treatment-related mortality was 13% (n= 2). Overall, acute graft-vs.-host disease (GvHD) occurred in 53% (8/15), with acute GvHD grade II or above occurring in 47% (7/15). In the 13 evaluable patients, chronic GvHD occurred in 46% (6/13), with this being extensive in three patients. These results suggest that a GvL effect can be delivered against poor-risk myeloid disorders with a low non-relapse mortality using this fludarabine-melphalan RIC protocol.

Acute Disease↗
PubMed2004

Giant osteomata of the mandible.

Osteomas are benign tumours of bone. They are uncommon in the jaws and usually present because of facial asymmetry or trismus. Osteomas arising from the lingual aspect of the mandibular ramus are rare and asymptomatic, usually discovered on routine radiography. We present two cases, and discuss their aetiology, presentation and management.

Adult↗
PubMed2004

Imaging modalities in head and neck oncology: a surgical perspective.

The application of imaging modalities to head and neck oncology is addressed from a surgical perspective. The optimal use of ultrasound, CT, MRI, PET and sentinel node biopsy to the management of salivary and oral neoplasia is discussed in the context of the primary lesion, the assessment of the neck, evaluation of the recurrent lesion and management of the palliative case.

Diagnostic Imaging↗
PubMed2003

In a population study, can parathyroid hormone aid the definition of adequate vitamin D status? A study of people aged 65 years and over from the British National Diet and Nutrition Survey.

The British National Diet and Nutrition Survey of people aged 65 years and over in 1994-5 provided nationally representative estimates of food and nutrient intakes and biochemical status indices. In a further analysis study, parathyroid hormone (PTH) concentrations were measured in plasma samples from 773 subjects and were analyzed with the existing data on vitamin D intake, plasma 25-hydroxyvitamin D (25OHD), total plasma calcium and albumin. As predicted, a strong inverse relationship was observed between PTH and 25OHD. In the free-living respondents aged 65-84 years (n=507) there was a continuous decline in PTH with increasing 25OHD and no plateau, whereas in free-living people aged 85+ years (n=86) there was a significant deviation from a simple inverse relationship, with unexpectedly high PTH values in some people with satisfactory 25OHD status. There was a relationship between both PTH (inverse) and plasma 25OHD (direct) with calcium intake. A direct relationship between 25OHD and total plasma calcium was not significant when calcium was corrected for albumin. Geographically, 25OHD, and to a lesser extent PTH, exhibited a north-south gradient, and 25OHD was associated with self-reported health status. Both 25OHD and PTH were associated with self-reported physical activity. Low calcium intake and 25OHD was associated with receipt of state benefits. The relationship between plasma 25OHD and vitamin D intake revealed a striking seasonal cycle. 25OHD was strongly influenced by vitamin D intake in the winter in free-living subjects, but this was not observed in the summer. In people living in institutions such as nursing homes, who are less likely to be exposed to sunlight throughout the year, plasma 25OHD levels were lower throughout the year.

Aged↗
PubMed2003

Quantitative measurement of patellofemoral joint stability: force-displacement behavior of the human patella in vitro.

Patellofemoral joint instability is a common clinical problem. However, little quantitative data are available describing the stability characteristics of this joint. We measured the stability of the patella against both lateral and medial displacements across a range of knee flexion angles while the quadriceps were loaded physiologically. For eight fresh-frozen knee specimens a materials testing machine was used to displace the patella 10 mm laterally and 10 mm medially while measuring the required force, with 175 N quadriceps tension. The patella was connected via a ball-bearing patellar mounting 10 mm deep to the anterior surface to allow natural tilt and other rotations. Patellar force-displacement behavior was tested at flexion angles of 0 degrees, 10 degrees, 20 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees. Significant differences were found between the lateral and medial restraining forces at 10 mm displacement. For lateral displacement, the restraining force was least at 20 degrees of knee flexion (74 N at 10 mm displacement), rising to 125 N at 0 degrees and 90 degrees of knee flexion. The restraining force increased progressively with knee flexion for medial patellar displacement, from 147 N at 0 degrees to 238 N at 90 degrees. With quadriceps tension, the patella was more resistant to medial than lateral displacement. Our finding that lateral patellar displacement occurred at the lowest restraining force when the knee was flexed 20 degrees agrees with clinical experience of patellar instability.

Aged↗