Search PubMed⌕ Search

Biomedical subjects

R Harrison

Publications and source records attributed to R Harrison.

At least 91 records · Page 5Linked to original sources
PubMed1997

Circulating anti-(xanthine oxidoreductase) antibodies in healthy human adults.

Levels of free anti-(xanthine oxidoreductase) (XOR) antibodies in the serum of normal healthy human subjects were determined, using both human and bovine enzyme as antigen, in an enzyme-linked immunosorbent assay (ELISA). Levels of IgM class anti-(human XOR) antibodies were found to be particularly high (mean values representing approximately 3% of total IgM) and to be significantly higher than levels of IgM anti-(bovine XOR) antibodies, indicating that endogenous XOR, rather than ingested bovine milk XOR, is the immunogen. IgM anti-XOR antibody levels were significantly higher in women under 50 years than in age-matched men, or in older women. Levels of IgG class anti-XOR antibodies were much lower and showed no correlation with gender or age. Affinity-purified anti-(human XOR) antibodies only partially inhibited enzymic activities of XOR. The majority of both IgM and IgG anti-(human XOR) antibodies in serum occurred as immune complexes, suggesting that the specific antibodies have a protective role in removing potentially damaging XOR from the circulation.

Adult↗
PubMed1997

The UPDRS scale as a means of identifying extrapyramidal signs in patients suffering from dementia with Lewy bodies.

The study aimed to evaluate the merits of the Unified Parkinson's Disease Rating Scale (UPDRS) in the assessment of parkinsonism in patients suffering from Dementia with Lewy Bodies (DLB). Parkinsonian symptoms were assessed in 73 dementia patients using the UPDRS and staged using the Hoehn & Yahr system. A staging of 1 or greater was taken to indicate significant parkinsonism. DLB (n=42) was diagnosed using the McKeith et al. criteria, Alzheimer's disease (n=30) was diagnosed using the NINCDS ADRDA criteria. The inability of some patients to comply with some of the more complicated tasks meant that the full UPDRS assessment could only be completed in 35 (83%) of the DLB patients, 23 (66%) of whom had significant parkinsonism. Patients with parkinsonism were significantly younger than those without. A Principal Components Analysis derived a sub-scale including the items tremor at rest, action tremor, bradykinesia, facial expression and rigidity. These items had a specificity of 100% and a sensitivity of 85% for significant parkinsonism using a cut-off of 7/8. The brief scale had several advantages over the complete UPDRS. Unlike the full scale it was independent of the severity of cognitive impairment and the 5 key items could be assessed in 41 (98%) of the DLB patients. Autopsies have been completed on 31 patients, with a specificity of greater than 90% for the operationalized clinical diagnosis of DLB. It is suggested that a 5 item subscale of the UPDRS provides a reliable and generally applicable instrument for the assessment of parkinsonism in DLB patients.

Aged↗
PubMed1997

Sepsis-induced depression of rat glucose-6-phosphatase gene expression and activity.

Sepsis in rats decreases the hepatic expression of the gluconeogenic enzyme glucose-6-phosphatase (G6Pase). The aim of this study was to investigate the relationship among G6Pase transcription, mRNA, enzymatic activity, and serum glucose levels at different intervals during mild or fulminant sepsis. Both fulminant and mild sepsis immediately decreased hepatic G6Pase mRNA levels. In mild sepsis, levels began to recover late in the time course. Serum glucose levels were maintained in mild sepsis but decreased markedly in fulminant sepsis. G6Pase transcription after fulminant sepsis decreased and never recovered. A similar transcriptional decrease was noted in mild sepsis, but some recovery occurred in this state. Histochemistry after mild sepsis revealed a decrease in G6Pase protein and enzymatic activity that paralleled transcription. These studies suggest that changes in G6Pase transcription and activity are early markers for sepsis-induced alterations in hepatic function. Mechanisms other than gene expression and enzymatic activity serve to maintain glucose levels in mild sepsis, but in the fulminant disorder, compensatory mechanisms fail and hypoglycemia develops.

Animals↗
PubMed1997

Schistosoma mansoni antigens applicable to diagnosis of prepatent infections.

Diagnosis of schistosomiasis still depends upon demonstration of eggs in excreta, by which time significant pathology may occur to the human host. This study was undertaken to identify Schistosoma mansoni antigen(s) to be exploited in serodiagnosis of prepatent and/or acute infections. Immunoglobulin G and M responses of inbred and outbed mice to Schistosoma mansoni whole adult worm antigen were monitored in immunoblots using sera obtained at sequential times from mice infected with either 600 or 100 Schistosoma mansoni cercariae each. Regardless of the initial infection dose, immunoblot reactions to two doublets, 31/32 and 34/35 kDa appeared as early as two and three weeks post infection respectively and reactions to 38 and 70 kDa antigens appeared after five weeks infection. Antigens 31/32 and 38 induced both IgG and IgM responses whereas 34/35 and 70 predominantly induced IgG response. Homologues of these four antigens equally reactive with serum of infected mice were also demonstrated in Schistosoma haematobium, worms. Examination of sera from 25 patients suffering from acute Schistosoma mansoni, two suffering from Schistosoma haematobium and 16 patients suffering from infections with other parasite species confirmed the potential of 31/32, 34/35 and 38 kDa antigens in the specific diagnosis of prepatent and acute schistosomal infections but showed cross-reactivity of the 70 kDa antigen.

Adolescent↗
PubMed1996

Can telemedicine be used to improve communication between primary and secondary care?

OBJECTIVE: To test feasibility and acceptability of teleconferencing routine outpatient consultations. DESIGN: Exploratory trial of teleconferenced outpatient referrals of general practitioners. SETTING: An inner city teaching hospital and surrounding general practices. SUBJECTS: Six general practices linked to hospital outpatient clinics. MAIN OUTCOME MEASURES: Levels of participants' satisfaction measured with self administered questionnaires. RESULTS: 54 teleconsultations were performed in 10 different specialties. Few serious technical problems were encountered, and high levels of satisfaction with the consultations were reported by patients, hospital specialists, and general practitioners. CONCLUSIONS: Teleconferenced consultations for routine outpatient referrals with joint participation of general practitioner were feasible. These may have an important potential benefit for improving communication between primary and secondary care.

Ambulatory Care↗
PubMed1996

Continuous arterial gas monitoring: initial experience with the Paratrend 7 in children.

OBJECTIVE: To describe clinical usage of the Paratrend 7 continuous arterial blood gas monitor in children. DESIGN: Children older than 24 months of age who required significant ventilatory intervention were eligible for sensor placement. INTERVENTIONS: The sensor was placed via the arterial catheter to measure pH, PCO2, PO2, and temperature. The simultaneous arterial blood gas value was recorded along with the sensor reading. RESULTS: The sensor functioned for as long as seven days and provided the clinicians with data on the patient's respiratory status. The statistical validity of the device when compared to the arterial blood gas showed that the bias/precision for pH was 0.006/0.024, for PCO2 -0.78/4.68 mmHg, and for PO2 1.9%/17.1% (mmHg). CONCLUSIONS: This report demonstrates actual clinical use of continuous blood gas monitoring in children. The information obtained is a major asset to the management of critically ill children in the intensive care unit.

Age Factors↗
PubMed1996

Determination of half-reaction equilibrium in a ping-pong enzyme mechanism.

Substituted enzyme (or ping-pong) mechanisms usually involve enzymes that exist in two forms that alternate during the catalytic reaction. A method is described here for determining the position of the equilibrium of a half reaction in a ping-pong enzyme mechanism that is based on the kinetics of the burst reaction which occurs upon addition of reactants that recycle the enzyme from one form to another. The theoretical basis for the analysis is developed, and the method is applied to the half reaction of the aldimine form of aspartate transaminase with difluoro-oxaloacetate.

Animals↗
PubMed1996

Genotypic analysis of infant macaques infected transplacentally and orally.

The SIV-infected macaque provides an excellent model to study factors involved in maternal-fetal transmission of HIV. In our prenatal transmission studies, female macaques were inoculated intravenously during midgestation with either SIV/DeltaB670 or a combination of SIV/ DeltaB670 and the macrophage-tropic molecular clone SIV/17E-Fr. The females harbored a genetically diverse virus population at parturition, whereas a single genotype from the maternal quasispecies was identified in the infants. One of two variants was transplacentally transmitted to the infants, SIV/17E-Fr or B670-Cl 12, a genotype contained within the SIV/ DeltaB670 inoculum. Both of these variants have been identified in the central nervous system of macaques that have developed encephalitis and they replicate in vitro on primary rhesus macrophages. These results suggest a critical role for macrophages in fetal infection in utero. In our perinatal transmission studies we have evaluated the viral genotypes found in two newborn macaques infected orally with SIV/DeltaB670 and in one infant infected via amniotic inoculation in late gestation. More than one viral genotype was identified in each infant, moreover, each infant harbored different genotypes. These results suggest different mechanisms are responsible for viral infection via these routes.

Amino Acid Sequence↗