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Biomedical subjects

P Davies

Publications and source records attributed to P Davies.

At least 37 records · Page 2Linked to original sources
PubMed2005

A new formula for blood transfusion volume in the critically ill.

BACKGROUND: Published formulae, frequently used to predict the volume of transfused red cells required to achieve a desired rise in haemoglobin (Hb) or haematocrit (Hct), do not appear to have been validated in clinical practice. AIMS: To examine the relation between transfusion volume and the resulting rise in Hb and Hct in critically ill children. METHODS: Phase 1: Sample of 50% of children admitted during 1997; 237 of these 495 patients received at least one packed red cell transfusion; 82 children were transfused without confounding factors that could influence the Hb/Hct response to transfusion and were analysed further. Actual rise in Hb concentration or haematocrit was compared to that expected from use of existing formulae. A new formula was developed. Phase 2: In 50 children receiving a packed red cell transfusion during 2001, actual rise in Hb concentration was compared to expected rise in Hb with use of the new formula. RESULTS: Phase 1: Existing formulae performed poorly; median ratio of actual/predicted rise in Hb or Hct ranged from 0.61 to 0.85. Using the regression coefficients new formulae were developed for both Hb and Hct. These formulae were applicable across all age and diagnostic groups. Phase 2: Median ratio of actual/predicted rise in Hb improved to 0.95 with use of the new formula. CONCLUSIONS: Existing formulae underestimate the volume of packed red cells required to achieve a target Hb or Hct. Adoption of the new formulae could reduce the number of transfusion episodes in PICU, cutting costs and reducing risk.

Adolescent↗
PubMed2005

Ability of a nurse specialist to diagnose simple headache disorders compared with consultant neurologists.

OBJECTIVE: To compare the ability of a headache nurse specialist and consultant neurologists in diagnosing tension-type headache and migraine. METHODS: An experienced neurology ward sister was trained in the differential diagnosis of headache disorders. Over six months, patients with non-acute headache disorders and role players trained to present with benign or sinister headaches were seen by both the nurse and a consultant neurologist. Both reached independent diagnoses of various headache disorders. RESULTS: Consultants diagnosed 239 patients with tension-type headache (47%), migraine (39%), or other headache disorders (14%). The nurse agreed with the consultant in 92% of cases of tension-type headache, 91% of migraine, and 61% of other diagnoses. Where the nurse did not agree with the diagnosis, most would have been referred for a consultant opinion. Both the nurse and the doctors misdiagnosed the same three of 13 role players. The investigation rate of the consultants varied between 18% and 59%. Only one clinically relevant abnormality was found on head scans and this was strongly suspected clinically. CONCLUSIONS: A headache nurse specialist can be trained to diagnose tension-type headache and migraine. A nationwide nurse led diagnostic headache service could lead to substantial reduction in neurology waiting times.

Adult↗
PubMed2004

Cloning and expression analysis of two novel PCTAIRE 3 transcripts from human brain.

PCTAIRE 3 is a member of the PCTAIRE subfamily of cdc2-related serine/threonine protein kinases. In the present study, cDNAs encoding two isoforms of PCTAIRE 3 have been cloned and the genomic organization of the human PCTAIRE 3 gene is reported. The gene spans 28.15 kb on chromosome 1q31-32 and contains 16 exons. The major transcript of PCTAIRE 3, designated PCTAIRE 3a, has an open reading frame that is 474 amino acids in length. Transcripts for PCTAIRE 3a were evident throughout the brain and in the majority of tissues analyzed. A second transcript containing an insert that adds 90 nucleotides to the third exon of the gene was also identified. This transcript, designated PCTAIRE 3b, encodes a polypeptide of 504 amino acids. Expression of PCTAIRE 3b was limited to several subcortical nuclei of the basal gangli and the spinal cord and substantial levels of this transcript were not evident outside of the central nervous system. Primary sequence comparisons between different cdc2-related serine/threonine protein kinases reveal that these proteins are most heterogeneous in their N-terminal domains and the PCTAIRE subfamily is further diversified by the presence of isoforms within this region.

5' Flanking Region↗
PubMed2004

Paediatric malignant tumours of the gastrointestinal tract in the West Midlands, UK, 1957-2000: a large population based survey.

BACKGROUND: To investigate the incidence, clinical characteristics and survival of malignant tumours of the gastrointestinal tract in children in the West Midlands in Britain over a 44-year span time, to identify any change over this period and to compare the data with the world literature. PROCEDURE: Retrospective population based study. Fifty-seven patients were identified from the records of the West Midlands Regional Children's Tumour Registry. Age-standardised incidence rates were calculated using the world standardised population method. Statistical tests used were the Log rank test and survival curves were produced using the Kaplan-Meier method. RESULTS: The age-standardised incidence of overall gut tumours during the period 1957-2000 was 1.10/million/year. The age standardised incidence of non-Hodgkin lymphoma (NHL) was calculated as 0.9/million/year and for adenocarcinoma 0.14/million/year. CONCLUSION: Malignant tumours of the gastrointestinal tract remain rare in children. No changing trends in incidence were observed over the 44-year period. NHL was the commonest malignancy overall and of the small bowel while equal number of adenocarcinoma and NHL were identified in the large bowel. There was no significant difference in survival between sexes, site and age groups in both NHL and adenocarcinoma. Survival has improved over the last four decades for NHL patients but remains poor for the adenocarcinoma patients.

Adolescent↗
PubMed2004

An assessment of the cost-effectiveness of fast tracking bacteriological specimens for mycobacteria.

A virtual model, using six predetermined criteria for fast tracking tuberculosis specimens was devised to improve the cost effectiveness of the MB/BacT system. All specimens received at a central laboratory were audited for the six criteria over a 6-month period. By assuming that only those specimens fulfilling these criteria were fast tracked the theoretical cost savings could be calculated. To prevent possible delay in speciating mycobacteria, the number of criteria were expanded to nine, and a further 6 month audit carried out. In the first 6-month period, 728 specimens were tested. Had the initial hypothetical criteria excluded some of the specimens, only 351 specimens would have been tested through the fast-track system at a saving of pounds sterling 942 (dollars 1696), (52%) of the total cost, but five culture results positive for environmental mycobacteria would have been delayed. In a second 6-month survey the criteria were expanded. Using these no positive culture would have been missed but the savings would only have been 26% of the total cost. Introducing exclusion criteria for rapid testing can improve the cost effectiveness of rapid culture methods with no important loss of clinically necessary information.

Bacteriological Techniques↗
PubMed2004

A new, low-volume protein substitute for teenagers and adults with phenylketonuria.

Some older patients with phenylketonuria (PKU) fail to consume their protein substitute (with or without vitamin and mineral supplements) in prescribed amounts, which contributes to poor blood phenylalanine control. PKU Express (Vitaflo), is a new low-volume (amino acids 72 g/100 g), low-carbohydrate, phenylalanine-free protein substitute with added vitamins and minerals designed for people with PKU over 8 years of age. In an open intervention study, the aim was to investigate its acceptability and effectiveness in a group of teenagers and adults with PKU. Twenty-three subjects (15 female; 8 male) with PKU, who had a median age of 17 years (range 8-37 years) took the substitute for 8 weeks. A 3-day prospective diet diary, height, weight, plasma amino acids, biochemical and haematological nutritional analytes were measured at weeks 0 and 8. Skin-puncture bloods for plasma phenylalanine were collected every 2 weeks. The median weight of protein substitute (with or without vitamin and mineral supplements) consumed decreased by 33% from 150 g (range 140-180) daily to 100 g (range 100-125) daily ( p <0.001). Median change in energy intake decreased by a median of 10% (95% CI 2.0 to 18.0) when compared to intake on original protein substitute. On PKU Express, the intakes of all nutrients exceeded the dietary reference values but none was excessively high. Blood phenylalanine decreased by a mean of 37 micromol/L (95% CI-27 to 102) during the trial. Body mass index decreased in 40% of subjects. Changes in blood phenylalanine or body mass index were not statistically significant. Most of the nutritional, haematological and biochemical indices stayed within normal reference ranges for the analytes studied. Sixteen (70%) of the subjects had low plasma selenium at the start, but only 13 (57%) at the study end. Plasma vitamin B12 was high in 8 subjects at the start of the study and 9 at the end. Twenty-one subjects (96%) stated that the product was convenient and easy to prepare. However, 7 (32%) described the smell and 9 (46%) the texture as the same as or worse than those of previous protein substitutes. Because of the use of the premeasured sachets, some subjects were able to prepare their own protein substitute for the first time. PKU Express is a safe, efficacious, protein substitute that significantly reduces the daily volume of prescribed protein substitute.

Adolescent↗
PubMed2004

Protein substitutes for PKU: what's new?

Protein substitutes are an essential component in the management of phenylketonuria. A series of studies at Birmingham Children's Hospital have investigated their optimal dosage, timing and practical administration as well as the efficacy and tolerance of novel protein substitutes. The key findings are as follows. (1). Lower dosages of protein substitute (1.2 g/kg per day of protein equivalent) adversely affect blood phenylalanine control in children aged 1-10 years. (2). There is wide variability in 24 h blood phenylalanine concentrations. (3). Adjusting protein substitute timing during daytime does not reduce blood phenylalanine variability. (4). Repeated 4 h administration of protein substitute throughout 24 h markedly reduces phenylalanine variability and leads to lower phenylalanine concentrations. (5). The new, concentrated, low-volume protein substitutes and amino acid tablet preparations are efficacious and well tolerated by patients. (6). Administration of protein substitute as a gel or paste has reduced difficulties with administration of protein substitute in children. These findings are important in rationalizing treatment strategies, improving patient compliance and overall in improving blood phenylalanine control.

Dietary Proteins↗
PubMed2004

Ballooned neurones in the limbic lobe are associated with Alzheimer type pathology and lack diagnostic specificity.

Ballooned neurones (BNs) are one of the pathological hallmarks of several neurodegenerative diseases, including Pick's disease, corticobasal degeneration and argyrophilic grain disease (AGD). They have also been described in Alzheimer disease (AD), but the frequency of BNs in AD has not been systematically addressed. In the present study, immunohistochemistry for alphaB-crystallin was used as a sensitive method to detect BNs to determine the frequency of BNs in the limbic lobe in AD. At least a few BNs were detected in the limbic lobe of virtually all AD cases, and their density correlated with Braak stage, as well as the density of neurofibrillary tangles and senile plaques in the limbic lobe. The density of BN tended to be greater in AD cases with concurrent AGD than in pure AD. Given the high prevalence of AD in brain banks for neurodegenerative disease and the frequent presence of BNs in these areas with alphaB-crystallin immunohistochemistry, the present findings further indicate that BNs confined to the limbic lobe lack specificity in diagnostic neuropathology.

Aged↗
PubMed2004

Natural history of hepatitis B in perinatally infected carriers.

OBJECTIVES: To establish natural seroconversion rates and incidence of hepatic pathology in perinatally infected hepatitis B carriers. METHODS: Seventy three perinatally infected hepatitis B carriers identified through maternal screening were evaluated. Fifty three were born to parents from the Indian subcontinent, nine were Oriental, six were Afro-Caribbean, and five were white. Median follow up was 10.24 (range 2.02-20.16) years. RESULTS: Only three of the children followed up had cleared hepatitis B surface antigen during this period, and 30% of the children had seroconverted to anti-HBe. Seroconversions to anti-HBe were observed in Asian (18/50) and white (4/5) children, but not in Oriental or Afro-Caribbean children. More girls (40%) than boys (23%) had seroconverted, but the difference was not significant. All children were asymptomatic with normal physical examination, growth, and development. Almost half (48%) of the hepatitis B e antigen (HBeAg) positive children had normal hepatic transaminases and liver function. Thirty five liver biopsies were performed in children with active virus replication (HBeAg or hepatitis B virus DNA positive) who were being considered for antiviral treatment as part of a clinical trial and were scored using the Ishak method. Two thirds (62%) of the children had mild hepatitis, 60% had mild fibrosis, and 18% had moderate to severe fibrosis. There was a weak correlation between histological evidence of hepatitis and hepatic transaminase activity, implying that biochemical monitoring of hepatic disease activity may be ineffective. CONCLUSIONS: These asymptomatic hepatitis B virus carrier children remain infectious in the medium to long term with notable liver pathology. They should receive antiviral treatment to reduce infectivity and to prevent further progression of liver disease. Hepatic transaminases alone are not a reliable marker of liver pathology, and liver histology is essential before consideration for antiviral treatment.

Adolescent↗
PubMed2004

Could nursery rhymes cause violent behaviour? A comparison with television viewing.

AIMS: To assess the rates of violence in nursery rhymes compared to pre-watershed television viewing. METHODS: Data regarding television viewing habits, and the amount of violence on British television, were obtained from Ofcom. A compilation of nursery rhymes was examined for episodes of violence by three of the researchers. Each nursery rhyme was analysed by number and type of episode. They were then recited to the fourth researcher whose reactions were scrutinised. RESULTS: There were 1045 violent scenes on pre-watershed television over two weeks, of which 61% showed the act and the result; 51% of programmes contained violence. The 25 nursery rhymes had 20 episodes of violence, with 41% of rhymes being violent in some way; 30% mentioned the act and the result, with 50% only the act. Episodes of law breaking and animal abuse were also identified. Television has 4.8 violent scenes per hour and nursery rhymes have 52.2 violent scenes per hour. Analysis of the reactions of the fourth researcher were inconclusive. CONCLUSIONS: Although we do not advocate exposure for anyone to violent scenes or stimuli, childhood violence is not a new phenomenon. Whether visual violence and imagined violence have the same effect is likely to depend on the age of the child and the effectiveness of the storyteller. Re-interpretation of the ancient problem of childhood and youth violence through modern eyes is difficult, and laying the blame solely on television viewing is simplistic and may divert attention from vastly more complex societal problems.

Child↗
PubMed2004

Performance of blood tests in diagnosis of inflammatory bowel disease in a specialist clinic.

AIMS: To determine the reliability of a panel of blood tests in screening for ulcerative colitis and Crohn's disease. METHODS: The subjects were 153 children referred to a paediatric gastroenterology department with possible inflammatory bowel disease (IBD). Of these, 103 were found to have IBD (Crohn's disease 60, ulcerative colitis 37, indeterminate colitis 6). The 50 without IBD formed the controls. Blood tests evaluated included haemoglobin, platelet count, ESR, CRP, and albumin. Receiver operating characteristic curves were used where possible to determine optimal threshold values. Binary logistic regression analysis was used to investigate the five screening tests in combination, and a stepwise method was used to find the best test combination. RESULTS: The optimal screening strategy used a combination of haemoglobin and platelet count and "1 of 2 abnormal" as the criterion for positivity. This was associated with a sensitivity of 90.8% (95% CI 83.3 to 95.7%), a specificity of 80.0% (95% CI 65.7 to 89.8%), and positive and negative predictive values of 94.4% and 75.9% respectively. CONCLUSIONS: Haemoglobin and platelet count provide a useful screening test combination for patients with suspected IBD. These tests are not completely reliable however. If clinical suspicion is high further investigations are required.

Adolescent↗
PubMed2003

Inclusion of HPV testing in routine cervical cancer screening for women above 29 years in Germany: results for 8466 patients.

In a prospective cohort study 8466 women attending routine cervical cancer screening were recruited. Colposcopy was performed on women with any degree of atypia on cytology and/or a positive high-risk human papillomavirus (HPV)-DNA test (HC2; Hybrid Capture 2((c))), and for a randomly selected sample of 3.4% women with negative findings on both. Quality control included reviews of cytology, histology, colposcopy images and retesting of samples with polymerase chain reaction. Test diagnostic performances were based on 7908 women who had complete baseline and follow-up results. Routine histology identified 86 women with high-grade cervical intraepithelial neoplasia (CIN2+), which was confirmed by review histology in only 46 cases. Sensitivity of routine cytology for the detection of CIN2+ was 43.5%, with a specificity, positive predictive value (PPV), negative predictive value (NPV) of 98.0, 11.4 and 99.7%, respectively. Sensitivity of the HC2 test for the detection of CIN2+ was 97.8%, with a specificity, PPV and NPV, of 95.3, 10.9 and 100%, respectively. No high-grade neoplasia was detected in the randomly selected control group. A negative HPV-test result, even in combination with a positive Papanicolaou (Pap) result, virtually excluded any risk of underlying high-grade disease, but this was not the case for a negative Pap result. These data show that HPV testing is of value for the detection or exclusion of prevalent CIN in a routine cervical cancer-screening setting and could be used for further risk classification of women for follow-up management.

Adult↗
PubMed2003

Free use of fruits and vegetables in phenylketonuria.

This study aimed to evaluate systematically the effect of the free use of fruits and vegetables containing an intermediate amount of phenylalanine (51-100 mg/100 g) on the biochemical control in children with phenylketonuria (PKU). Fifteen subjects with PKU, with a median age of 6 years (range 1-24 years) were studied. In a three-part prospective 15-week study, subjects sequentially ate fruits and vegetables containing phenylalanine 0-50 mg/100 g for weeks 1 to 3; 51-75 mg/100 g for weeks 4 to 8; and 76-100 mg/100 g for weeks 9 to 15. Plasma phenylalanine concentrations were measured twice daily for three consecutive days in weeks 1, 3, 6, 8, 11, 13 and 15. A standard menu was followed on the blood sampling days. Daily dietary records of fruits and vegetables under study were kept throughout the trial. Control of phenylalanine concentrations was not adversely affected by the free use of fruits and vegetables containing 51-100 mg/100 g. Pre-breakfast median plasma concentrations were: weeks 1 to 3, 260 micromol/L (range 90-890); weeks 4 to 8, 255 micromol/L (range 130-920); and weeks 9 to 15, 278 micromol/L (range 30-880). Pre-evening meal median plasma phenylalanine concentrations were: weeks 1 to 3, 240 micromol/L (range 30-820); weeks 4 to 8, 210 micromol/L (40-880); and weeks 9 to 15, 238 micromol/L (range 20-880). These data suggest that free use of fruits and vegetables containing 51-75 mg/100 g poses no problem for children with PKU.

Adolescent↗
PubMed2003

Administration of protein substitute and quality of control in phenylketonuria: a randomized study.

Uneven administration of an L-amino acid protein substitute is an important contributing factor in variability in plasma phenylalanine concentrations over the 24-hour period in patients with phenylketonuria under treatment. The aim of this study was to determine whether manipulating the timing of protein substitution would reduce variability in plasma phenylalanine over 24 h. Sixteen children (aged 1-11 years) with well-controlled phenylketonuria were entered into a randomized crossover study in which four protocols of the same daily dose of protein substitute administration were compared. In protocol A, three equal, divided doses were given with meals over 10 h; in protocol B, three equal doses over 14 h; in protocol C, four equal doses over 14 h; and in protocol D, six equal doses over 24 h (3 subjects only). Four-hourly skin puncture blood specimens were collected for 48 h in each study protocol. In protocols A, B and C, but not in protocol D, there was wide variability in 24 h plasma phenylalanine. The median daily differences (micromol/L) between highest and lowest phenylalanine concentrations were: for protocol A, 140; for protocol B, 100; for protocol C, 120; and for protocol D, 40. In protocol D, 97% of all phenylalanine concentrations were below 120 micromol/L and no concentration fell below 40 micromol/L. Administration of protein substitute overnight as well as during daytime produces stable and lower plasma phenylalanine concentrations and may lead to improved dietary phenylalanine tolerance.

Amino Acids↗