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Biomedical subjects

A Baker

Publications and source records attributed to A Baker.

At least 145 records · Page 8Linked to original sources
PubMed1996

Prospective audit of multiple penetrating injuries to the colon: further support for primary closure.

Solitary colon injuries are being increasingly managed by intraperitoneal primary closure. The optimal management of the colon wound in multiple injuries of the colon, which have a high mortality, has not been determined. From 1983-1989, 668 patients sustained colonic injuries. In 71 of these patients the colon was injured at more than one site. Of the 597 single injuries to the colon, 472 (79%) were due to stabs and 102 (17%) to gunshot wounds. Sixty-eight men and three women sustained injuries at more than one site in the large intestine. The median age of patients was 26 years (range 13-66). In 61 patients the colon was injured at two sites and in seven patients at three sites. Three patients had more than three sites injured. The injuries were inflicted by: gunshots 35 (49%); stabs, 30 (42%); shotguns, three; and blunt trauma, three. Forty-one patients were treated by intraperitoneal primary closure (IPC) and 30 by a colostomy procedure or exteriorization of the primarily sutured colon (EPSC). Penetrating Abdominal Trauma Index (PATI) scores were high at 32 +/- 6, and were similar for all methods of colon wound management. Twenty-four patients were suffering from shock on admission, 13 of those patients were treated by primary repair and 11 were treated by an exteriorization procedure. Individuals treated by an exteriorization procedure stayed in hospital significantly longer, 45 days versus 21 days (P < 0.004) and had a higher mortality rate, five deaths versus one death (P < 0.04) than those patients who were primarily repaired. Intraperitoneal primary closure of all wounds is the method of choice for the majority of multiple injuries. Colostomy procedures or EPSC contribute to morbidity and mortality.

Adult↗
PubMed1995

Investigation of the energy requirement and targeting signal for the import of glycolate oxidase into glyoxysomes.

The uptake of glycolate oxidase into peroxisomes has been studied using an in vitro import system. Import of glycolate oxidase was found to be ATP-dependent and temperature-dependent and specific for glyoxysomes. In these respects it resembles the import of isocitrate lyase into both glyoxysomes and leaf-type peroxisomes; thus the ATP-dependence and temperature dependence appear to be general properties of plant microbody protein import. Two mutant versions of glycolate oxidase were prepared lacking 59 amino acids of the N-terminus and 53 amino acids of C-terminus, respectively. Both were capable of ATP-dependent import, whereas a fusion protein consisting of the cytosolic protein dihydrofolate reductase linked to the last 20 amino acids of glycolate oxidase bound to glyoxysomes but did not enter the organelle.

Adenosine Triphosphate↗
PubMed1995

Factors which influence alterations of phosphates and pH in exercising human skeletal muscle: measurement error, reproducibility, and effects of fasting, carbohydrate loading, and metabolic acidosis.

Previous studies have shown considerable variability in the metabolic response of human skeletal muscle during a standardized exercise protocol. The goal of these studies was to investigate the factors responsible for the broad range of metabolic changes produced by fatiguing exercise. Experiments were performed to quantitate the measurement error of 31P nuclear magnetic resonance spectroscopy of human muscle, the reproducibility of changes within a single subject, and the effects of fasting, carbohydrate loading, and metabolic acidosis. The results show that none of these factors appear to be responsible for the wide variation between subjects. However, the effects of training and genetic factors were not investigated and are likely to be responsible for the substantial variability between subjects.

Acidosis↗
PubMed1995

FMS mutations in patients following cytotoxic therapy for lymphoma.

Point mutations at codons 301 and 969 of the FMS proto-oncogene have been reported in both myelodysplasia (MDS) and acute myeloid leukaemia (AML). We report here the incidence of such mutations in patients at risk of developing secondary MDS and AML. Peripheral blood DNA from 70 patients in remission from lymphoma was screened for mutations by oligonucleotide (ONH) using mutant specific probes. Codon 969 mutations were detected in 11 of the 70 (15.7%) cases. No codon 301 mutations were detected. Five of these mutations were confirmed using an independent technique (single nucleotide primer extension analysis, SNPE) and a further mutation was detected in a single patient using single-stranded conformational polymorphism analysis (SSCP). No codon 969 mutations were detected in 62 lymphoma biopsy specimens from these patients or from three patients with detectable FMS mutations where pre-therapy marrow was investigated by ONH. No mutations at either codons 301 or 969 were detected by ONH in 61 normal controls. Somatic mutations at codon 969 of the FMS gene occur commonly following cytotoxic therapy for lymphoma and their detection indicates the presence of a clonally expanded population of abnormal cells.

Adult↗
PubMed1995

Copper-associated liver disease in childhood.

BACKGROUND/AIMS: Indian childhood cirrhosis is associated with high liver copper concentrations and progressive liver disease with a high mortality. Early treatment with penicillamine was found to reduce mortality and reverse liver damage. We aimed to define the clinical features of copper-associated liver disease outwith the Indian subcontinent and encourage the earlier consideration of the syndrome in cryptogenic liver disease. METHODS: Three European children presented between 10 and 29 months of age with abdominal distension, pyrexia and hepatosplenomegaly. Over 1-5 weeks their condition deteriorated rapidly due to liver failure. Two died within 2 months of onset and one received a successful liver transplant. In two cases consideration of the diagnosis occurred only on examination of the liver after orthotopic liver transplant or death. Light microscopy was used, with haematoxylin and eosin, reticulin and orcein stains. Tissue, plasma and water copper levels were measured by flame atomic absorption spectrometry. RESULTS: All had micronodular cirrhosis and severe hepatocellular necrosis with Mallory bodies and copious-orcein positive material. Liver copper concentrations ranged from 1100-1310 micrograms/g dry weight. For two patients domestic water with high copper content had been used for the preparation of feeds. No environmental source of excess copper could be identified in the third case. CONCLUSIONS: We suggest that the above condition, which is called Indian childhood cirrhosis in the Indian subcontinent and Copper Storage Disease elsewhere, would be better named 'Copper-Associated Liver Disease in Childhood', emphasising the need to consider this disorder in unexplained liver disease and to seek possible sources of excessive copper intake.

Child, Preschool↗
PubMed1995

HIV risk-taking behaviour among injecting drug users currently, previously and never enrolled in methadone treatment.

This study compares the injecting and sexual risk-taking behaviour among injecting drug users (IDUs) currently, previously and never enrolled in methadone maintenance treatment (MMT). All subjects had injected during the 6 months prior to the day of interview. The current MMT group showed significantly lower injecting risk-taking behaviour subscale scores on the HIV Risk-taking Behaviour Scale (HRBS) of the Opiate Treatment Index than the previous MMT and non-MMT groups together. The current MMT group differed from the other two groups in the frequency of injecting and cleaning of injection equipment with bleach. There was no difference between the current MMT group and the other two groups combined in sexual risk-taking behaviour scores on the HRBS. There were no differences between the previous MMT and non-MMT groups in injecting and sexual risk-taking behaviour. HIV seroprevalence was low and there was no difference in seroprevalence between groups. Thus, IDUs currently enrolled in MMT are at reduced risk for HIV infection when compared with IDUs who have previously or never been enrolled in MMT. However, the absence of a difference between the current MMT and other two groups in frequency of sharing behaviours suggests the need for additional strategies among MMT clients to reduce needle-sharing. Possible strategies include the application of relapse prevention interventions and the availability of sterile injecting equipment in MMT clinics. Further research is needed to identify factors which increase attraction and retention of IDUs to MMT.

Acquired Immunodeficiency Syndrome↗
PubMed1995

The prognostic significance of caffeine half-life in saliva in children with chronic liver disease.

To evaluate its clinical value, the half-life of caffeine (1,3,7-trimethylxanthine) in saliva (SCT) after 3 mg/kg-1 oral caffeine was measured in 53 children with chronic liver disease (mean age, 4.41 years) and 48 control children (mean age, 6.26 years) in five samples over 24 h and compared with parameters of liver function and outcome. Sensitivity was 60.3% and specificity 97% of SCT for diagnosis of chronic liver disease. The correlation of SCT with serum albumin (ALB) was -0.52 (p < 0.001), total bilirubin (SBR) was 0.585 (p < 0.001), prolonged prothrombin time (PT) was 0.387 (p = 0.004), and aspartate aminotransferase (AST) was 0.538 (p = 0.001). The correlation of SCT with a clinical score of liver dysfunction calculated from the presence of features of hepatic decompensation was 0.627 (p < 0.001) and with Malatack's paediatric prognostic score was 0.505 (p < 0.001). Serial SCT and liver function tests were performed on 53 patients on 127 occasions during a mean follow-up of 361 days (range, 4-709). Of this group, 18 were listed for liver transplantation. Predictive values of outcome by analysis of variance expressed as ratio of mean squares were SBR, 34.1 (p < 0.001); log10 SCT, 20.6 (p < 0.001); ALB, 5.2 (p < 0.05); PT, 1.2 (NS). SCT correlated with clinical and biochemical parameters of severity of liver disease, but SBR was a better predictor of listing for liver transplantation in this group of paediatric patients.

Adolescent↗
PubMed1995

Liver transplantation for neonatal haemochromatosis.

Two cases of neonatal haemochromatosis, a rare and often fatal metabolic disorder, presenting with acute liver failure, are reported. Both presented in the first week of life with hypoglycaemia, jaundice, and coagulopathy, with rapid deterioration of liver function. Both received a transplantation using reduced liver grafts. One child was well 18 months later. Few survivors have been reported and despite the difficult perioperative management, liver transplantation is the best treatment for neonatal haemochromatosis.

Female↗
PubMed1995

Role of re-screening of cervical smears in internal quality control.

AIMS: To investigate the use of rapid re-screening as a quality control method for previously screened cervical slides; to compare this method with 10% random re-screening and clinically indicated double screening. METHODS: Between June 1990 and December 1994, 117,890 negative smears were subjected to rapid re-screening. RESULTS: This study shows that rapid re-screening detects far greater numbers of false negative cases when compared with both 10% random re-screening and clinically indicated double screening, with no additional demand on human resources. The technique also identifies variation in the performance of screening personnel as an additional benefit. CONCLUSION: Rapid re-screening is an effective method of quality control. Although less sensitive, rapid re-screening should replace 10% random re-screening and selected re-screening as greater numbers of false negative results are detected while consuming less resources.

Cytological Techniques↗
PubMed1995

Evaluation of a new embryo-grading system to predict pregnancy rates following in vitro fertilization.

This study examines two descriptive parameters of embryo morphology to determine if either parameter correlates with subsequent pregnancy rates (PRs). The two parameters were the evenness (similarity in size) of the blastomeres and the degree of cellular fragmentation. A total of 242 embryo transfers in which 4 embryos were transferred were included. Sixty-nine (28.5%) clinical and 62 (25.6%) viable pregnancies resulted. In all cases 4 embryos were transferred, but the number of embryos with even round blastomeres (grade 1) varied from 0 to 4. Statistically, there was no correlation between PR and number of grade 1 embryos transferred. When 4 grade 1 embryos were transferred, the PR was 33.3 versus 28.1% when no grade 1 embryos were transferred. There was, however, a statistical difference in the implantation rate; a higher frequency of multiple gestations occurred when 3 or 4 of the embryos transferred were graded 1:12.7 as compared with 6.7% when < or = 2 embryos were grade 1. The significance of the degree of cellular fragmentation in the embryos was also assessed. There was no statistical difference in the PR according to the number (0-4) of embryos transferred that did not have fragments (grade A). When 4 grade A embryos were transferred, the PR was 18.2 versus 26.1% when there were no grade A embryos. Neither implantation nor multiple birth rates correlated with fragmentation.

Adult↗
PubMed1994

Drug use and HIV risk-taking behaviour among injecting drug users not currently in treatment in Sydney, Australia.

This study investigated the drug use patterns and HIV risk-taking behaviour of 200 injecting drug users (IDU) not currently in treatment in Sydney, Australia. Although there was low HIV seroprevalence, unsafe injecting and sexual practices were common. Variables that were predictive of injecting risk-taking were higher level of heroin use, sexual relationship with an IDU and greater polydrug use. Two variables were predictive of sexual risk-taking: higher level of hallucinogen use and sexual relationship with an IDU. Female subjects were significantly more likely to have an IDU sexual partner. A higher level of cannabis use was associated with greater polydrug use and a higher level of amphetamine use was associated with greater use of opiates other than heroin. The findings are discussed in terms of the need for interventions aimed towards reducing sexual risk-taking among users of hallucinogens and towards reducing injecting and sexual risk-taking among IDU and their sexual partners. The potential difficulty in producing behaviour change among polydrug users is highlighted.

Adolescent↗
PubMed1994

Comparison of the cumulative probability of pregnancy after in vitro fertilization-embryo transfer by infertility factor and age.

OBJECTIVE: To compare the cumulative probability of pregnancy after multiple IVF cycles by age and cause of infertility. DESIGN: A prospective study was done in which patients were followed from the time they registered for their first IVF cycle until they achieved a clinical pregnancy, withdrew from treatment, or study was terminated. PATIENTS, SETTING, TREATMENTS: Infertile women undergoing IVF-ET at the Cooper Institute for In Vitro Fertilization were enrolled in this study if the luteal phase leuprolide acetate (LA) and hMG controlled ovarian hyperstimulation (COH) regimen was used. MAIN OUTCOME MEASURES: Clinical pregnancy, as determined by a positive beta-hCG level and ultrasonographic confirmation of a gestational sac, and delivery rates based on number of women with live births were compared by infertility factor and age. RESULTS: The 3-month cumulative probability of pregnancy based on life table analysis was 33% in women with tubal factor who were < or = 35 years of age, 25% in women with tubal factor who were > 35 years of age, 30% for women with multiple factors who were < or = 35 years of age, and 14% for women with multiple factors who were > 35 years of age. The rate for the older women with multiple factors was significantly lower than that for the other groups. The delivery rates were lower for the women with multiple factors than for women under 35 with tubal factor only. CONCLUSIONS: There is a significant effect of age and infertility factor on pregnancy and delivery rates. Physicians should consider these factors in evaluating their patients' prospects for success in IVF-ET.

Adult↗
PubMed1994

[Measuring vibrations by laser doppler vibrometry of the human tympanic membrane after stapes fixation].

At times preoperative diagnosis of otosclerosis can prove difficult. Even the objective measurement of the stapes reflex is not very conclusive in patients suffering from more severe hearing loss. Laser-Doppler vibrometry measures the velocity or amplitude of the tympanic membrane (umbo) vibrations. Laser-Doppler vibrometry has a sensitivity that is highly by the factor 10(4) than tympanometry. The herewith presented examinations show, that there is a correlation between the frequency patterns of the displacement amplitudes and experimentally simulated otosclerosis.

Fourier Analysis↗
PubMed1994

Controlled evaluation of a brief intervention for HIV prevention among injecting drug users not in treatment.

This study evaluated the effectiveness of a brief intervention (BI), a one-session motivational interview, in reducing HIV risk-taking behaviour among injecting drug users (IDU) not enrolled in any form of treatment for drug dependence. IDU were randomly assigned to either BI or a non-intervention control condition (NIC). One hundred and twenty-one subjects were successfully contacted for a 3-month follow-up and 88 subjects were followed up at 6 months. There were significant reductions for the sample as a whole for injecting risk-taking subscale scores on the HIV Risk-taking Behaviour Scale between pre-treatment and follow-up. There was no significant change in sexual risk-taking behaviour. There were no significant differences between groups on any measure at 3- and 6-month follow-up. There are a number of possible reasons why the sample as a whole showed significant improvements from initial to follow-up assessments. It is possible that, having had their attention directed to their risk-taking behaviour, subjects attempted to reduce their injecting risk-taking behaviour. If this is the case and subjects in the NIC condition can be considered as having received a BI, this suggests that BIs involving a personal risk assessment are effective in reducing risk behaviours associated with injecting. However, this suggestion could only be confirmed by comparison with a non-assessment control group.

Adolescent↗
PubMed1994

Neuromuscular control of lifting in the elderly.

The aim of this investigation was to determine, utilising an electromyographic (EMG) technique, the influence of the ageing process on the neuromotor control of the stoop-lift. Seven elderly (60-75 years) and seven young (18-25 years) subjects completed a series of ten unresisted (no weight) stoop-lifts. EMG potentials were recorded with 4-mm bipolar surface electrodes from the erector spinae and medial hamstring muscle groups. The temporal features of the stoop-lift itself were recorded with an electrogoniometer. The results of this investigation showed that the elderly subjects had a significantly (p < 0.05) earlier onset of the erector spinae muscle during the up-phase of the stoop-lift compared to the younger subjects. In addition, reactivation of the erector spinae muscle in the up-phase occurred at hand positions significantly (p < 0.05) closer to the floor in the elderly group indicating more stooped postures. Thus the EMG profiles of the erector spinae within the elderly subjects performing unresisted stoop-lifts approximated those previously reported in younger subjects performing resisted (with a weight) lifting. The earlier onset of the erector spinae in the up-phase of the stoop-lift was partially explained by a significant (p < 0.05) reduction in flexibility (sit and reach test) associated with the elderly subjects. The results further stress the potential for injury associated with the utilisation of the stoop-lift, particularly by elderly populations.

Adolescent↗
PubMed1994

Middle ear transmission disorders--tympanic membrane vibration analysis by laser-Doppler-vibrometry.

Laser-Doppler-vibrometry is a useful method to measure vibrations of the tympanic membrane. It is suitable to objectively diagnose the middle ear. In comparison to tympanometry, laser-Doppler-vibrometry has greater sensitivity. Temporal bone specimens were specially prepared to simulate middle ear disorders like middle ear effusion, fixation of the malleus head, fixation of the stapes footplate and removal of the incus. A correlation between the displacement function of the umbo and the experimentally produced middle ear disorders could be demonstrated. For the first time it was possible to measure the vibration of the tympanic membrane by using a laser-Doppler-vibrometer in a healthy 25-year-old male.

Adult↗
PubMed1994

Lipopolysaccharide is a frequent contaminant of plasmid DNA preparations and can be toxic to primary human cells in the presence of adenovirus.

Endotoxin (lipopolysaccharide, LPS) is commonly found as a contaminant in plasmid DNA preparations. We demonstrate here that the quantities of LPS typically contaminating DNA preparations can generate a toxicity to primary cells (primary human skin fibroblasts, primary human melanoma cells) in the presence of entry-competent adenovirus particles. Toxicity can be observed with as little as 100 ng/ml free LPS or 100 pg/ml LPS when the LPS is assembled into polylysine/adenovirus complexes. Simple and effective methods of removing the contaminating LPS using either a polymyxin B resin or Triton X-114 extraction are described. Treatment of DNA samples to remove LPS eliminates the toxicity to primary cells.

Adenoviridae↗