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Biomedical subjects

J Anderson

Publications and source records attributed to J Anderson.

At least 523 records · Page 29Linked to original sources
PubMed1990

Hepatitis B vaccine in the prevention of perinatally transmitted hepatitis B virus infection: final report on a West Midlands pilot study.

A four-dose vaccination schedule was used to interrupt perinatal transmission of hepatitis B virus from carrier mothers to their babies. Of 49 babies immunised and successfully followed up, 43 (88%) became immune: 15 out of 21 (71%) of babies born to HBeAg + mothers became immune, the other 6 becoming the only carrier babies in the study. Without immunisation a carrier rate in excess of 70% would have been expected in this high-risk group. Vaccine alone, given in a rapid immunisation schedule, protected the majority of babies at risk. In those babies in whom the carrier state occurred in spite of immunisation, infection may have taken place in utero, or the infant may have failed to produce adequate antibody in response to the vaccine.

Carrier State↗
PubMed1990

Transgenic tobacco plants and their progeny derived by microprojectile bombardment of tobacco leaves.

Transgenic tobacco plants and progeny carrying coding sequences for neomycin phosphotransferase II (NPTII) and beta-glucuronidase (GUS) were recovered following microprojectile bombardment of tobacco leaves. Transgenic plants were regenerated from bombarded leaf pieces of tobacco cvs. 'Xanthi' and 'Ky 17' which were cultured in the presence of 100 or 200 micrograms/ml kanamycin for six to eight weeks. Among 160 putative transgenic plants from at least 16 independent transformation events 76% expressed NPTII, and 50% expressed GUS. Southern analysis of plants expressing either one or both of the enzymes indicated DNA in high molecular weight DNA in 8 of 9 independent transformants analyzed. Two independent transformants and their progeny were analyzed in detail. Analysis of progeny for quantitative enzyme levels of NPTII and GUS, and Southern analysis of parents and progeny clearly demonstrated that the genes were transmitted to progeny. One transformant demonstrated Mendelian ratios for seed germination on kanamycin-containing medium while the other transformant had non-Mendelian ratios. DNA analysis of progeny indicate complex integration of the plasmid DNA, and suggest that rearrangements of this DNA has occurred. These results are consistent with other methods of direct DNA uptake into cells, and verify that the microprojectile bombardment method is capable of DNA delivery into intact plant cells which can give rise to transgenic plants and progeny.

Blotting, Southern↗
PubMed1990

Pulmonary vascular pressure profile in 2-3-week-old, 5-6-week-old and adult ferrets.

We have previously reported age-related differences in the pattern of vascular pressure drop in rabbit lungs (Raj et al., Pediatric Res. 20:1107-1111, 1986). The purpose of this study was to investigate if there were similar age related differences in the ferret lung. To determine the profile of vascular pressures and the longitudinal distribution of vascular resistance in arteries, microvessels and veins, we isolated and blood perfused lungs of 20 ferrets (8 adults greater than 6 months of age; six 5-6-week-old and six 2-3-week-old). All lungs were perfused under similar experimental conditions with blood flow adjusted to keep pulmonary artery pressure constant at approximately 20 cmH2O, when left atrial pressure was 8 cmH2O. Lungs were inflated to 6 cmH2O airway pressure with a gas mixture so that blood Po2 was greater than 100 Torr. Microvascular pressure measurements were obtained in each lung in subpleural 20-50 microns diameter arterioles and 20-50 microns diameter venules using the micropipette servonull method. Blood flow achieved in all three groups of lungs was similar. We found that in adult ferret lungs, 40% of total vascular resistance was in arteries, 40% in microvessels and 20% in veins. In 2-3-week-old and 5-6-week-old ferret lungs, the fractional distribution of resistance in arteries, microvessels and veins was similar to that in adult ferret lungs. We conclude that, unlike in the rabbit, the pulmonary vascular pressure profile does not change with age in the ferret.

Aging↗
PubMed1990

Smooth pursuit eye tracking dysfunction and negative symptoms in schizophrenia.

This study examined the hypothesis that negative symptoms are associated with abnormalities of smooth pursuit in schizophrenic patients. The pursuit eye movements of 25 subjects with schizophrenia and 25 matched normal control subjects were recorded using an infrared eye tracking system and quantified using the log of signal-to-noise ratio (1n S/N). The severity of negative symptoms within the schizophrenic group was rated using the Scale for the Assessment of Negative Symptoms. Previous findings of pursuit abnormalities among schizophrenic patients as a group were replicated. There was, however, no significant association between the eye tracking dysfunction and the severity of negative symptoms.

Adolescent↗
PubMed1990

Effect of high dose norepinephrine versus epinephrine on cerebral and myocardial blood flow during CPR.

Several animal studies have demonstrated an improvement in cerebral blood flow (CBF) and myocardial blood flow (MBF) after the administration of epinephrine (E) 0.20 mg/kg during closed chest CPR. The administration of norepinephrine (NE) in doses of 0.12 and 0.16 mg/kg demonstrated a trend toward improved CBF and MBF during CPR over that seen with E 0.20 mg/kg in the same animal model. The purpose of this study was to compare the effects of a higher dose of NE 0.20 mg/kg to E 0.20 mg/kg to determine if increasing doses of NE would demonstrate further improvement in CBF and MBF during CPR. Fourteen immature swine were anesthetized and instrumented for regional blood flow and hemodynamic measurements. After 10 min of ventricular fibrillation (VF), CPR was begun using a mechanical thumper. After 3 min of CPR, the animals received either E 0.20 mg/kg (n = 7) or NE 0.20 mg/kg (n = 7) through a right atrial catheter. CPR was continued for an additional 3.5 min and defibrillation was then attempted. CBF (ml/min/100 g), MBF (ml/min/100 g), myocardial oxygen delivery (MDo2; ml O2/min/100 g), myocardial oxygen consumption (MVo2; ml O2/min/100 g), and myocardial oxygen extraction ratios (ER, MVo2/MDo2) were measured during normal sinus rhythm (NSR), during CPR, and during CPR following drug administration. Following drug administration, CBF, MBF, MDo2 and MVo2 rose while ER fell in both E and NE groups. There were no significant differences between groups in CBF, ER, or intravascular pressures following drug administration (P greater than or equal to 0.07). The NE group demonstrated significantly higher MBF (118.9 +/- 73.1 vs. 62.2 +/- 45.3, P = 0.04), MVo2 (14.2 +/- 7.7 vs. 7.0 +/- 3.8, P = 0.05), and MDo2 (19.9 +/- 13.4 versus 9.4 +/- 6.3, P = 0.05) compared to the E group following drug administration While NE improved MBF and MDo2 over E during CPR, there was a trend toward lower resuscitation rates with NE (57.1% vs. 85.7% P = 0.56). Any benefit of higher MBF and MDo2 with NE 0.20 mg/kg appears to be offset by proportionately high MVo2 and a trend toward lower resuscitation rates in the NE 0.20 mg/kg animals.

Animals↗
PubMed1990

Observations on the pathogenicity for sheep and goats and the transmissibility of the strain of virus isolated during the rinderpest outbreak in Sri Lanka in 1987.

The pathogenicity for sheep and goats of the virus strain that caused acute rinderpest in cattle and domestic buffalo in Sri Lanka after an interval of over 40 years has been examined. The results show that it can cause overt clinical disease in goats, but only mild or unapparent infection in sheep. The disease was transmitted from infected sheep to in-contact susceptible sheep and calves.

Animals↗
PubMed1990

Evaluation of the use of chromogenic and fluorogenic substrates in solid-phase enzyme linked immunosorbent assays (ELISA).

Fluorogenic and chromogenic substrates were used in direct and trapping enzyme-linked immunosorbent assays (ELISA) for the detection of mouse IgG and foot-and-mouth disease virus (FMDV). The detection limits for both antigens were compared using different combinations of enzymes and substrates. Various times and concentrations of chemicals were used to obtain maximum sensitivity for both systems. Similar sensitivities were found using fluorogenic and chromogenic substrates. Tetramethyl benzidine substrate for horse-radish peroxidase enzyme conjugates was found to attain the highest sensitivity levels for chromogenic assays (0.12 ng IgG/ml and 1.0 ng/ml FMDV respectively), after 10 min incubation. Of the two fluorogenic enzyme/substrates studied, B-galactosidase was the most sensitive but required extended incubation times (2-3 h) as compared with chromogenic systems. Special microplates for fluoro-immunoassay (FIA) were compared with conventional microplates and no advantage was found to justify their use. An alkaline phosphatase anti-guinea-pig conjugate was used to confirm the equivalence of fluorogenic and chromogenic substrates in terms of sensitivity. A comparison of the amount of signal generated using various concentrations of enzyme in the absence of antigen was made for two different alkaline phosphatase conjugates to obtain theoretical sensitivity limits. One possible advantage of fluorogenic substrates is that high binding ratio can improve the confidence in discrimination of positive results.

Animals↗
PubMed1990

Individual differences in men's perceptions of and reactions to thinning hair.

Data obtained from 91 American male respondents, ranging in age from 23 to 66 years of age, indicated that a personality trait, public self-consciousness, pertaining to habitual attention to and concern for public self-aspects, was related to both perceptions of men with thinning hair and reactions to one's own thinning hair. Men with high public self-consciousness were not only more likely to believe that balding men were less attractive, but were also more likely to believe that balding men were less desirable romantic partners for women. Furthermore, faced with their own hair loss, they expressed greater concern and were more willing to try prescription hair remedies to grow thicker hair than were their low self-consciousness counterparts. Despite the concern that hair loss appears to cause many men, there was no evidence that the onset of hair loss caused changes in level of public self-consciousness.

Adult↗
PubMed1990

Fourier analysis of ventricular fibrillation of varied aetiology.

Fast Fourier Transform analysis was used to study ventricular fibrillation induced by several different methods in 43 greyhounds anaesthetized with sodium pentobarbitone. The dominant frequency at the body surface of ventricular fibrillation induced electrically in non-ischaemic hearts was initially 9.9 +/- 0.7 Hz, remained above 9 Hz for 70 s and then rapidly fell to 5 Hz. The dominant frequency of ventricular fibrillation induced by acute occlusion (initially 12.3 +/- 0.2 Hz), or by reperfusion (12.2 +/- 0.4 Hz) of the anterior descending branch of the left coronary artery, showed a similar time-course. However, ventricular fibrillation induced by administration of potassium (4.8 +/- 0.8 Hz) or ouabain (7.1 +/- 1.1 Hz) was significantly slower. Fibrillation recorded from the endocardium of the heart initially showed a similar dominant frequency to that recorded at the body surface, but there was no significant fall in frequency over 3.3 mins. There was little difference in the time-course of fibrillation in the non-ischaemic heart recorded directly from the epicardium or from a surface lead. These findings may be of relevance to the poor response to DC countershock after prolonged ventricular fibrillation, hyperkalaemia or cardiac glycosides.

Animals↗
PubMed1990

Risk factors for behavioral and emotional disorder in preadolescent children.

The relationship between risk factors and behavioral and emotional disorder was examined in 792 11-year-old children. Background characteristics such as sex, maternal depression, marital status of the parents, and reading problems distinguished between children with and without disorder. It also appeared that disorder was related to the number of risk factors experienced. This study, like others, failed to provide strong support for differences in background characteristics among children with different diagnoses. This may reflect the degree of overlap among disorders, because even children with only a single disorder may not be entirely free of the symptomatology of other disorders. For this reason it is important to assess children for multiple disorders or at least consider impaired functioning in other dimensions.

Affective Symptoms↗
PubMed1990

Cavitating pulmonary nodules in histiocytosis-X high resolution CT demonstration.

In a case of pulmonary histiocytosis, high resolution C.T. scanning (H.R.C.T) showed multiple small ring shaped peripheral pulmonary lesions. This has not, to our knowledge been previously reported in the radiological literature. The possible pathogenesis of these lesions is described. With the advent of H.R.C.T this appearance should become more widely recognised in the future. H.R.C.T was of considerable assistance in diagnosis of this patient with non-specific findings on the plain chest film.

Adult↗
PubMed1990

Striatal kinetics of [11C]-(+)-nomifensine and 6-[18F]fluoro-L-dopa in Parkinson's disease measured with positron emission tomography.

The kinetics in brain of the dopamine reuptake blocking agent [11C]-(+)-nomifensine and the L-dopa analogue 6-[18F]fluoro-L-dopa were compared in 3 patients with idiopathic Parkinson's disease and age-matched healthy volunteers using positron emission tomography. Regional uptake was analyzed and quantified according to a 3-compartment model. Retention of both tracers in striatal regions of the parkinsonian patients were reduced compared with the healthy volunteers mainly in the putamen, while the caudate nucleus was only mildly affected. The reductions were considerably less than the decrease previously reported postmortem for striatal dopamine content in the basal ganglia of patients with Parkinson's disease. A fairly constant ratio between 6-[18F]fluoro-L-dopa utilization and [11C]-(+)-nomifensine binding in the caudate nucleus and the putamen were found in both groups unrelated to the size of the estimated parameters. This indicates that a limiting factor for the utilization of exogenous levodopa in Parkinson's disease may be a reduced transport capacity for the amino acid into the dopaminergic terminals.

Adult↗
PubMed1990

Ultrastructure and antigenicity of the unique cell wall pimple of the Candida opaque phenotype.

Cells of Candida albicans WO-1 switch frequently and reversibly between two colony-forming phenotypes, white and opaque. In the white form, budding cells appear similar to those of most other strains of C. albicans, but in the opaque form, budding cells are larger, are bean shaped, and possess pimples on the wall. These pimples exhibit a unique and complex morphology. With scanning electron microscopy, a central pit can be discerned, and in many cases, a bleb can be observed emerging from the pimple center. With transmission electron microscopy, channels are evident in some pimples and vesicles are apparent under the pimple in the cytoplasm, in the actual wall of the pimple, or emerging from the tip of the pimple. A large vacuole predominates in the opaque-cell cytoplasm. This vacuole is usually filled with spaghettilike membranous material and in a minority of cases is filled with vesicles, many of which exhibit a relatively uniform size. An antiserum to opaque cells recognizes three opaque-cell-specific antigens with molecular masses of approximately 14.5, 21, and 31 kilodaltons (kDa). Absorption with nonpermeabilized opaque cells demonstrated that only the 14.5-kDa antigen is on the cell surface; indirect immunogold labeling demonstrated that it is localized in or on the pimple. The possibility is suggested that the vacuole of opaque cells is the origin of membrane-bound vesicles which traverse the wall through specialized pimple structures and emerge from the pimple with an intact outer double membrane, a unique phenomenon in yeast cells. The opaque-cell-specific 14.5-kDa antigen either is in the pimple channel or is a component of the emerging vesicle. The functions of the unique opaque-cell pimple and emerging vesicle are not known.

Antigens, Fungal↗
PubMed1990

Pulmonary arterial and venous constriction during hypoxia in 3- to 5-wk-old and adult ferrets.

We have determined the sites of hypoxic vasoconstriction in ferret lungs. Lungs of five 3- to 5-wk-old and five adult ferrets were isolated and perfused with blood. Blood flow was adjusted initially to keep pulmonary arterial pressure at 20 cmH2O and left atrial and airway pressures at 6 and 8 cmH2O, respectively (zone 3). Once adjusted, flow was kept constant throughout the experiment. In each lung, pressures were measured in subpleural 20- to 50-microns-diam arterioles and venules with the micropipette servo-nulling method during normoxia (PO2 approximately 100 Torr) and hypoxia (PO2 less than 50 Torr). In normoxic adult ferret lungs, approximately 40% of total vascular resistance was in arteries, approximately 40% was in microvessels, and approximately 20% was in veins. With hypoxia, the total arteriovenous pressure drop increased by 68%. Arterial and venous pressure drops increased by 92 and 132%, respectively, with no change in microvascular pressure drop. In 3- to 5-wk-old ferret lungs, the vascular pressure profile during normoxia and the response to hypoxia were similar to those in adult lungs. We conclude that, in ferret lungs, arterial and venous resistances increase equally during hypoxia, resulting in increased microvascular pressures for fluid filtration.

Aging↗
PubMed1990

Pulmonary venous responses to thromboxane A2 analogue and atrial natriuretic peptide in lambs.

To characterize pulmonary venous vasoactivity and the factors that modulate it, we determined venous responses to a vasoconstrictor agent, thromboxane A2 (TXA2) analogue U46619, and to a vasodilator agent, atrial natriuretic peptide (ANP), in 28 isolated blood-perfused lamb lungs under conditions of varying vascular tone and intraluminal pressures. TXA2 was given in a 5 micrograms/kg bolus followed by a steady infusion of 1 micrograms/kg/min to three groups of lungs: group 1, n = 4, with low vasomotor tone; group 2, n = 8, with moderate vasomotor tone; and group 3, n = 7, with moderate vasomotor tone and high venous intraluminal pressures. Group 3 lungs were reverse-perfused to obtain high venous pressures. ANP was given as two 10 micrograms/kg bolus injections, 5 minutes apart, to three groups of lungs: group 4, n = 4, with low vasomotor tone; group 5, n = 5, with moderate vasomotor tone; and group 6, n = 8, with high vasomotor tone. Group 6 lungs were vasoconstricted with TXA2 infusion. In all lungs, we measured blood flow and pressures in the pulmonary artery and left atrium and partitioned the venous segment by measuring pressures in 20-80-microns venules by micropuncture. We found that the venous constrictor response to TXA2 was greatest in lungs with moderate basal vasomotor tone and low venous intraluminal pressures. In lungs with low vasomotor tone or high venous intraluminal pressures, the venous response to TXA2 was attenuated. The vasodilator response to ANP was negligible in lungs with low vasomotor tone, probably because they were already maximally vasodilated, but similar in lungs with moderate and high vasomotor tone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Effect of fasting on hyperoxic lung injury in mice. The role of glutathione.

Fasted mice exposed to 100% oxygen have more lung damage and die sooner than do fed mice. The mechanism responsible for this phenomenon has not been identified. We performed the following experiments to test the hypothesis that reduced glutathione content in lung tissue of fasted mice contributes to the increased susceptibility to hyperoxic lung damage. First, air-exposed mice were fasted for as long as 3 days. They had little change in lung levels of superoxide dismutase (SOD) or catalase, but they had a 41% decrease in glutathione by Day 3 (p less than 0.001). Second, fed mice and fasted mice were exposed to 100% oxygen for as long as 4 days. Both groups had nearly identical values of lung SOD and catalase, but the fasted mice had lower levels of glutathione (p less than 0.001). Third, fed mice received the glutathione synthesis inhibitor buthionine sulfoximine (BSO; 20 mM) in their drinking water for 2 wk and were then exposed to either air or 100% oxygen. Air-exposed mice receiving BSO for 14 days had no change in lung SOD content, a 43% increase in catalase (p less than 0.001), and a 41% decrease in glutathione (p less than 0.01). Oxygen-exposed, BSO-treated mice had no change in SOD and an increase in catalase, but lower glutathione levels, more deaths, and increased lung damage on Day 3 (BAL protein: 1.72 +/- 0.21 versus 0.94 +/- 0.08 mg/ml; p less than 0.01) than did diluent-treated mice. Fourth, fasted mice were given liposomes containing glutathione intratracheally.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗