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Biomedical subjects

P Wright

Publications and source records attributed to P Wright.

At least 181 records · Page 10Linked to original sources
PubMed1990

Role of staphylococcal toxin production in blepharitis.

Lid isolates of Staphylococcus aureus and coagulase-negative staphylococci (CNS) from controls (12 S. aureus and 110 CNS) and from patients with blepharitis (17 S. aureus and 171 CNS) were tested for production of alpha, beta, delta, epsilon, and previously undescribed hemolytic toxins, because toxin production has been implicated as a cause of blepharoconjunctivitis. The electrolyte content of agar media required for toxin production was first investigated. Alpha-lysin was found to be produced by all isolates of S. aureus colonizing lids of normal controls and patients with blepharitis, but by none of 281 CNS isolates. A new toxin was identified, having low molecular weight (5 kd), produced by one CNS strain isolated from a blepharitic lid. It was produced on basic nutrient agar that lacked sodium but contained glucose, which inhibited production of alpha-lysin. It hemolyzed rabbit and sheep erythrocytes and, surprisingly, was neutralized by polyclonal antiserum to alpha-lysin. This may explain occasional reports of alpha-lysin production by CNS. The overall results do not support a hypothesis of hemolytic toxin production by staphylococci as a general cause of blepharitis.

Bacterial Toxins↗
PubMed1990

Acanthamoeba keratitis--resistance to medical therapy.

Successful medical therapy of Acanthamoeba keratitis has been reported with combination therapy; topical Brolene and neomycin. Resistance has not so far been identified as a problem, but was the basis for recurrent disease observed in a patient with bilateral infection. Eradication of amoebae was finally achieved following prolonged topical therapy and two corneal grafts in each eye. Topical anti-amoebic therapy with paromomycin, benzethonium chloride, clotrimazole and R11/29 (a phenanthridinium compound), was continued for three months post-operatively. No further recurrences occurred during 14 months' follow-up. Drug sensitivities were performed for three isolates of Acanthamoeba sp (group II) which demonstrated the development of resistance to Brolene and arsenic. In addition, the resistant isolates were temperature-sensitive mutants which would not grow at temperatures above 30 degrees C. This could explain 'culture-negative' results in some cases of clinical recurrence when incubation of laboratory samples had only been performed at 37 degrees C.

Acanthamoeba Keratitis↗
PubMed1990

Marital relations in incest offenders.

The study compared 92 incest perpetrators to 40 (noncriminal) married males on two marital inventories, the Clarke Martial Relations Questionnaire (CMRQ), and the Sexual Behavior and Marital Satisfaction Questionnaire (SBMSQ). Results showed that marital disharmony, in the form of mistrustfullness, lack of mutual friends and time together, emotional instability (in both partners), but not sexual relations, were predominant factors in incest perpetrators' profiles. A discriminant function analysis correctly classified 91.3% of incest offenders, but only 30.0% of controls, into their a priori group. Incest perpetrators reported less mutual give-and-take in disagreements with their spouses, a trend to confide less in their wives, and being more lonely in their marriage. Incest offenders reported they knew their spouses less well prior to marriage, despite the lack of any between-group differences in length of marriage or number of prior marriages. No differences emerged with respect to the range of sexual behaviors experienced or the degree of satisfaction with them. There were no group differences in the frequency of coitus nor in sexual dysfunction. In general, the lack of a satisfying emotional relationship between the incest offenders and their wives appeared as the most prominent factor in their marital relationships. The prominent aspects of their marital disharmony and sexual relations identified in the study reflect, in part, the inherent treatment goals needed for the incest perpetrator.

Adult↗
PubMed1990

Overwhelming odds: caregiving and the risk of institutionalization.

In this study we explored whether informally or formally provided long-term care services reduce the risk of institutionalization among the impaired elderly and the nature of the relationship between support and risk. We relied principally on the 1982 National Long-Term Care Survey (NLTCS) with supplementary data from the 1984 NLTCS and the national American Housing Survey. Five specific types of effects were tested: direct effects of formal and informal care on institutional risk; buffering effects of support moderating risk factors; supplementation effects of formal support on the risk-reducing impact of informal care; facilitating effects of the housing environment in enabling support to continue; and intervening effects mediating the direct effects. The effects of each type of support differ substantially. The analyses do not confirm the notion that formal, paid care reduces institutional risk. In fact, the use of paid caregivers is associated with greater risk of institutionalization, other things equal. The results for informal care are more mixed. A general measure that accounts for all types of informal support has no effect on institutional risk in any of the formulations tested. But the marginally significant effects of quality and proximate support in the direct effects model are consistent with the hypothesis that caregiving reduces institutional risk. The findings also indicate that a small number of housing or locational features are facilitators of formal support and particular types of informal support.

Activities of Daily Living↗
PubMed1989

Comparative effects of the isomers of bepridil on isolated coronary and aortic arteries.

The vasodilator actions of racemic bepridil were compared with those of its laevo-(l) and dextro-(d) rotatory isomers in isolated rabbit aorta and pig coronary artery. The actions of bepridil (B), (l) B and (d) B were further compared with those of drugs known to act either by blockade of calcium entry or to inhibit calmodulin in pig coronary artery. (l) B and (d) B were equipotent in relaxing tonic contractions induced by phenylephrine in rabbit aorta but (d) B was approximately twice as potent as (l) B in relaxing tonic contractions induced by potassium (K+). Both (d) B and (l) B relaxed K+-induced contractions in coronary artery and, in higher concentrations, inhibited and N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide (W7) were equipotent against both types of contraction whilst nifedipine and verapamil failed to reduce histamine-induced contractions. Both isomers of bepridil (like W7) shifted concentration-response curves to histamine in non-depolarized coronary artery in a noncompetitive manner. No potency differences were found between (l) B and (d) B in this tissues. It is concluded that intracellular actions, possibly calmodulin inhibition, play a substantial role in the vasodilator action of bepridil, a conclusion supported by the relative lack of stereospecificity shown by the bepridil isomers.

Animals↗
PubMed1989

Staphylococcal infection and the limbus: study of the cell-mediated immune response.

The relationship between enhanced cell-mediated immunity (CMI) to staphylococcal antigens, expressed as delayed hypersensitivity (DH), and the development of catarrhal infiltrates at the limbus in the rabbit has been explored by others. This DH is required for infiltrates to develop in the rabbit cornea when it is exposed to conjunctival inoculation with live Staphylococcus aureus cells. Similar investigations have not been pursued in the human, although St. aureus has been isolated from lids of patients with sterile marginal ulcers. We have tested 69 patients with blepharitis, eleven with and 58 without associated symptomatic marginal keratitis, for DH to killed whole cells of St. aureus and St. epidermidis and protein A; quantitative cultures have also been collected from lids and conjunctivae. Preliminary findings show that nine out of 11 patients with symptomatic marginal keratitis, requiring treatment with steroids, have enhanced DH to St. aureus cell wall antigens. We suggest the hypothesis that this type of marginal keratitis in the human is the result of enhanced CMI at the limbus to St. aureus cell wall antigens.

Adult↗
PubMed1989

Benorylate hydrolysis by human plasma and human liver.

1. Benorylate (4-acetamido phenyl-O-acetylsalicylate) hydrolysis in vitro by human plasma and by human liver microsomes and cytosol has been investigated. 2. Benorylate was hydrolysed by a route involving initial hydrolysis of the acetyl group to yield phenetsal followed by hydrolysis to paracetamol and salicylate. Hydrolysis via acetylsalicylate was minor. 3. Benorylate was more actively hydrolysed by liver cytosol than microsomes and about 10 times faster than plasma. 4. Following a single oral dose benorylate (4 g) to volunteers only salicylate and paracetamol were detected in the plasma. 5. The therapeutic effects of benorylate appear to be mediated by salicylate and paracetamol.

Acetaminophen↗
PubMed1989

Human liver and plasma aspirin esterase.

The plasma, in addition to the liver, is a major site of hydrolysis of aspirin. Human plasma and liver aspirin esterase activities in samples from a group of patients varied over a two fold range and there was a significant correlation between individual plasma and liver activities. Human liver aspirin esterase was present in the cytosolic and microsomal fractions. Cytosolic and microsomal enzymes had different activities and apparent affinities for aspirin.

Aged↗
PubMed1989

Corneal subepithelial monoclonal kappa IgG deposits in essential cryoglobulinaemia.

A 60-year-old man suffering from photophobia and visual disturbances was found to have bilateral superficial corneal grey-white gelatinous deposits. An abnormal cold-precipitable serum component was found and characterised as homogeneous IgG-kappa immunoglobulin. Corneal immunohistochemical examination revealed subepithelial IgG-kappa deposits, focally replacing Bowman's layer. The patient underwent superficial keratectomy in both eyes with satisfactory visual results.

Cornea↗
PubMed1988

Learning experiences in feeding behaviour during infancy.

In early infancy, the method of feeding from either the breast or the bottle results in the establishment of different patterns of meal size across the day. In breast-fed infants the change in size of meals across the 24 hr period is evidence for the acquisition of an anticipatory pattern of intake which is unlikely to occur in bottle-fed infants because of restrictions in the amount of milk offered at each meal. Other measures of behaviour within feeds support the development of a baby-controlled style of feeding in breast-fed infants compared with a mother-controlled feeding style in the bottle-fed infant. Associated with these patterns of intake are variations in the perceived hunger of infants by their mothers, with hunger variation being recognized with greater frequency in females than in males. In older infants the establishment of cultural rules of eating and the use of parental strategies to manipulate eating in children provide further evidence for the importance of learning in the establishment of early feeding behaviour.

Breast Feeding↗
PubMed1988

The effect of age upon the affinity of microsomal mono-oxygenase enzymes for substrate in human liver.

Although the clearance of many oxidized drugs falls with age, a corresponding fall in the maximal activities of drug metabolizing enzymes has not been noted. The possibility of a fall in enzyme affinity for substrate with age, which could account for the observed changes, has not previously been investigated in human liver. We have studied the kinetics of the microsomal mono-oxygenase 7-ethoxycoumarin-O-de-ethylase in 17 human liver biopsy specimens. No correlation was observed between age and microsomal protein recovery, maximal enzyme activity or apparent enzyme affinity. Since microsomal mono-oxygenase activities and affinities appear not to change in human liver, other factors such as a fall in liver volume or blood flow must be responsible for the decline in clearance of many oxidized drugs which occurs with ageing.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1988

Immunofluorescent studies in ocular cicatricial pemphigoid.

Twenty nine patients with cicatrizing conjunctivitis were studied; 17 with a clinical diagnosis of cicatricial pemphigoid, five with a clinical diagnosis of pseudopemphigoid caused by long-term application of topical medication and seven who had a cicatrizing conjunctivitis from other causes. Biopsies from clinically uninvolved bulbar conjunctiva were taken for direct immunofluorescence and blood was taken for indirect immunofluorescence using normal human conjunctiva, oral mucosa and skin as substrates. On direct immunofluorescence, in vivo bound immunoglobulins were found along the basement membrane in 10 of the 17 patients with cicatricial pemphigoid, one of the five with pseudopemphigoid and two of the seven with a cicatrizing conjunctivitis associated with other diseases. Circulating anti-basement membrane zone antibodies were found only when conjunctiva was used as a substrate. These were present in seven of the patients with cicatricial pemphigoid, three of those with pseudopemphigoid and two of those with a cicatrizing conjunctivitis caused by other diseases. These results indicate that direct immunofluorescence is a useful, but not absolute diagnostic marker for ocular cicatricial pemphigoid. The results in the pseudopemphigoid group argue that this is an immunologically mediated disorder indistinguishable from spontaneous cicatricial pemphigoid and probably triggered by the drugs. The presence of circulating antibodies should allow for precise identification of the antigen involved in cicatricial pemphigoid using SDS electrophoresis and Western blot analysis.

Adult↗
PubMed1988

Inner city deprivation and medical education: a survey of medical students by medical students.

A total of 330 preclinical and clinical medical students and house officers at St Mary's Hospital were surveyed by questionnaire to assess their knowledge and experience of inner city deprivation and health, and their opinions on the role of the doctor in responding to these problems. The response rate was 87%. Over 75% of the respondents had had no experience of inner city living conditions before coming to medical school, and they gained little experience during the medical course until well into the clinical years. Most preclinical students wanted more contact with the community early in the course; less than one-third of the clinical students wanted this. The differences in knowledge and attitudes between the year groups are discussed and possible reorientation in medical education is considered.

Attitude of Health Personnel↗
PubMed1988

Sexual sadism: brain, blood, and behavior.

The behavior of sadists is bizarre and poorly understood. There are gross endocrine and brain abnormalities in a small number of these men. Approximately two-fifths show subtle temporal lobe brain abnormalities that are logically linked to sexual behavior and require further exploration. It would be interesting to explore the interface of the endocrine system and the brain--that is, to determine if there are interactive processes that may be related to the development of sexual anomalies, perhaps early in life as suggested by Kolarsky et al. Certainly, biological factors cannot determine whether an individual will act on his sexual impulses. Many psychological factors, such as family background and substance abuse, play a significant role in the dangerousness of the individual. However, it appears that biological factors are noteworthy in sexual sadism. Brain pathology, especially, shows some correlation with force used in offences and likelihood of recidivism, and for this reason alone it merits further study.

Aggression↗
PubMed1988

Effects of nitroprusside on lung mechanics and hemodynamics after endotoxemia in awake sheep.

We examined the effects of intravenous sodium nitroprusside (NP) infusion on pulmonary arterial pressure (Ppa), pulmonary vascular resistance (PVR), dynamic compliance (Cdyn), resistance to airflow across the lungs (RL), and alveolar-arterial O2 pressure gradient (PAO2-PaO2) (room air) after endotoxemia in awake sheep. NP infused 2.5 h after endotoxin administration immediately reduced mean Ppa from 30 +/- 3 to 17 +/- 3 (SE) cmH2O, PVR from 6.3 +/- 0.7 to 4.8 +/- 0.5 cmH2O.l-1.min, and RL from 340 +/- 48 of base line to 205 +/- 73% and increased Cdyn from 54 +/- 5 of base line to 80 +/- 14% without affecting PAO2--PaO2. Ppa and lung mechanics returned immediately to preinfusion levels when NP was stopped. In vitro experiments with NP showed a dose-dependent relaxation of preconstricted pulmonary artery and vein, carbachol-preconstricted sheep tracheal strips, and bronchial rings. We conclude that NP reverses pulmonary hypertension and lung mechanics abnormalities after endotoxin and that this is due to effects of NP on airway and vascular smooth muscle. The return of these abnormalities after NP cessation suggests the continued presence of vascular and airway-constricting factors late after endotoxin. The lack of effect of NP on blood oxygenation suggests that deleterious effects on hypoxic vasoconstriction are offset by improved lung mechanics.

Animals↗
PubMed1988

Assessment of cardiac function in patients with the acquired immunodeficiency syndrome.

We have assessed right and left ventricular function by multigated radionuclide ventriculography in 12 consecutive patients with acquired immunodeficiency syndrome (AIDS) grouped according to the CDC classification system for HIV infection. Results were correlated with clinical, electrocardiographic and echocardiographic findings. Clinical examination and chest x-ray films showed no evidence of acute cardiac or pulmonary pathology. Five patients had evidence of ventricular dysfunction by radionuclide ventriculography along with significant ECG abnormalities. Three patients had abnormal ECG findings with normal ejection fractions. Echocardiography showed no evidence of significant valvulopathy or pericardial disease except for one patient with fibrinous strands associated with the pericardium. Decreased ejection fractions did not correlate with disease classification, risk group or survival. This study suggests that a major percentage of AIDS patients have some evidence of cardiac abnormalities. We conclude that abnormal ECG findings in an AIDS patient should alert the clinician to possible underlying ventricular dysfunction.

Acquired Immunodeficiency Syndrome↗