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Biomedical subjects

J Ferguson

Publications and source records attributed to J Ferguson.

At least 181 records · Page 10Linked to original sources
PubMed1994

Photoallergic contact dermatitis to oxybenzone.

A 21-year-old woman developed an erythematous papulovesicular eruption of photo-exposed sites, following the use of an oxybenzone-containing sunscreen. Patch testing, photopatch testing, phototesting, and histology produced findings strongly suggestive of oxybenzone photoallergy. Photopatch testing with a monochromator source showed abnormal UVA responses, with evidence of immediate urticaria, and delayed-onset dermatitis. Sun-barrier use is associated with a risk of the development of contact or photocontact allergic reactions. The benzophenones are frequently used in high-protection factor sun-barrier preparations, and appear to have a particular ability to induce such responses.

Adult↗
PubMed1994

The photosensitivity dermatitis and actinic reticuloid syndrome: no association with lymphoreticular malignancy.

In the management of photosensitivity dermatitis/actinic reticuloid syndrome (PD/AR) (syn. chronic actinic dermatitis), a chronic and often severe photodermatosis, there has been concern that patients may be predisposed to the development of lymphoreticular malignancy. A follow-up study of 231 patients with PD/AR who had been investigated at the Photobiology Unit, Ninewells Hospital, Dundee, between 1971 and 1991, was undertaken to determine (i) the incidence and type of malignancies (ii) the causes of any deaths. This information was obtained from three sources: (a) National Cancer Registry data, (b) death certificates, (c) when possible or practical, by casenote review. Thirty-eight malignancies had occurred (in 37 of the 231 patients). Although six of the 38 malignancies were lymphoma registrations, it emerged from a review of casenotes, pathology reports and death certificates that five of the six were incorrect: two were labelled 'mycosis fungoides' prior to diagnosis of PD/AR; a case of dermatopathic lymphadenopathy was initially reported as Hodgkin's disease; clerical errors had occurred in two cases. The remaining case was a true B-cell lymphoma. The occurrence of one lymphoreticular malignancy is not significantly different from the number expected in a normal population (0.96), when applying 5-year age-, sex-, and site-specific incidence rates to the cumulative patient years of risk [standardized incidence ratio 1.04 (95% CI 0.03-5.79)]. There was also no significant increase in the risk of non-lymphoma malignancies in the PD/AR subjects. Since diagnosis, 83 patients have died, the majority from cardiorespiratory or cerebrovascular diseases, or the reported malignancies, a pattern expected in an elderly population.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Sesquiterpene lactone mix is not an adequate screen for Compositae allergy.

70 patients suspected or known to have contact allergy to Compositae were patch tested with 0.1% sesquiterpene lactone mix (SL mix) and individual Compositae oleoresins. There were no apparent cases of active sensitization by, or irritancy from, the SL mix. 6 patients had allergic reactions to both SL mix and Compositae oleoresins, while 11 patients had allergic reactions to Compositae oleoresins with a negative reaction to the SL mix. In all but 2 of these, Compositae allergy was considered clinically relevant. As 0.1% SL mix picked up only 35% of cases of Compositae allergy, we do not consider it an adequate screen.

Adolescent↗
PubMed1994

Three-year outcome after balloon aortic valvuloplasty. Insights into prognosis of valvular aortic stenosis.

BACKGROUND: To identify predictors of long-term outcome after balloon aortic valvuloplasty, we analyzed data on 674 adults (mean age, 78 +/- 9 years; 56% were women) undergoing this procedure at 24 clinical centers who had a mean initial increase in aortic valve area of 0.3 cm2. METHODS AND RESULTS: Baseline data included clinical, echocardiographic, and catheterization variables. Follow-up data included mortality, cause of death, rehospitalization, 6-month echocardiography, and functional status. Kaplan-Meier curves and log-rank tests were used to evaluate survival in subgroups. Multivariate Cox regression models were used to identify independent predictors of survival. Overall survival was 55% at 1 year, 35% at 2 years, and 23% at 3 years, with the majority of deaths (70%) classified as cardiac by an independent review committee. Rehospitalization was common (64%), although 61% of survivors at 2 years reported improved symptoms. Echocardiography at 6 months (n = 115) showed restenosis from the postprocedural valve area of 0.78 +/- 0.31 cm2 to 0.65 +/- 0.25 cm2 (P < .0001). With stepwise multivariate analysis, sequentially adding clinical, echocardiographic, and catheterization variables, the overall model identified independent predictors of survival as baseline functional status, baseline cardiac output, renal function, cachexia, female gender, left ventricular systolic function, and mitral regurgitation. Baseline and postprocedural variables were examined to identify which subgroup of patients has the best outcome after aortic valvuloplasty. A "lower-risk" subgroup (28% of the study population), defined by normal left ventricular systolic function and mild clinical functional limitation, had a 3-year survival of 36% compared with 17% in the remainder of the study group. CONCLUSIONS: Long-term survival after balloon aortic valvuloplasty is poor with 1- and 3-year survival rates of 55% and 23%, respectively. Although survivors report fewer symptoms, early restenosis and recurrent hospitalization are common.

Adult↗
PubMed1994

Bupropion in tricyclic antidepressant nonresponders with unipolar major depressive disorder.

Tricyclic antidepressant (TCA) medications are among the most widely used pharmacologic treatments for depression. However, a substantial number of patients fail to respond to these agents. Few standardized trials of pharmacologic treatments for TCA nonresponders are available. Bupropion has an apparently different mechanism of action than TCAs and represents a possible treatment for the TCA nonresponder. Based on positive results from pilot studies, a standardized study evaluating bupropion in TCA nonresponders was conducted. Forty-one depressed outpatients who had failed to respond to adequate documented TCA treatment, defined by specific criteria of dosage, duration, and plasma concentrations, entered a 1-week single-blind placebo phase, followed by an open 8-week bupropion treatment phase utilizing doses of up to the maximum daily dose of 450 mg. Response was measured by change on the Hamilton Depression Rating Scale (HAM-D), Clinical Global Impressions-Severity (CGI-S) and Improvement (CGI-I) Scales, and the Hamilton Anxiety Rating Scale (HAM-A). Bupropion treatment resulted in an improvement in depression on all outcome measures. Forty-nine percent were considered "responders," in that they achieved > or = 50% improvement on the 28-item HAM-D. Fifty-four percent were classified as responders based on a CGI-I rating of much or very much improved. Statistically significant improvement in depressive symptoms, measured by mean scores for the HAM-D, CGI-S, and HAM-A, was achieved at the end of the study (as compared to baseline). Twelve patients (32%) had a HAM-D score of < or = 10 at termination.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Intravascular platelet aggregation and spontaneous contrast.

The purpose of this study was to determine why spontaneous contrast developed after general anesthesia in dogs. Twenty-seven dogs underwent echocardiography before and after pentobarbital or chloralose-urethane general anesthesia. The results showed that none of the 12 dogs receiving pentobarbital and 10 of 15 dogs receiving chloralose-urethane anesthesia developed contrast, in association with large platelet and platelet-neutrophil aggregates (P < 0.01); this effect could also be reproduced in vitro. The administration of adenosine diphosphate or antiplatelet antibody to nine dogs confirmed that intravascular platelet aggregation can cause ultrasonic contrast. The implications of these findings for patients with spontaneous contrast are discussed.

Anesthesia, General↗
PubMed1993

Characterization of the insulin A-chain major immunogenic determinant presented by MHC class II I-Ad molecules.

Data are presented which demonstrate the minimal insulin peptide required to activate a large group of insulin-specific T hybrids following presentation by either live or fixed APC, is the N-terminal insulin-A(1-13) peptide. Functional activation and competition assays using both live and fixed APC with 19 synthesized variants of the N-terminal bovine insulin A-chain molecule permitted classification of peptide residues into MHC agretope and T cell epitope regions. Our findings indicate insulin A-chain peptide occupies the Ag binding groove of class II MHC in an extended conformation as a result of intracellular reduction of A-loop disulfide bonds. Insulin A-chain Cys7 and Cys11 residues represent two independent T cell epitopes N- and C-terminal to the A-loop region. Data are presented that demonstrate the unique residues associated with several insulin isoform molecules contribute to the peptide agretope region. Our findings may suggest peptide agretopes may subtly modify the peptide/MHC conformation presented to TCR.

Amino Acid Sequence↗
PubMed1993

Protein kinases are required for embryonic neural crest cell galvanotaxis.

Embryonic quail neural crest cells migrate towards the negative pole of an imposed dc electric field as small as 7 mV/mm (0.4 mV per average cell length). The involvement of protein kinases in the mechanism utilized by these cells to detect and respond to such imposed fields was tested through the use of several kinase inhibitors. Evidence for the involvement of protein kinase C (PKC) included: (1) inhibition of the directed motility by 1 microM sphingosine that was reversed by the addition of the phorbol ester, PMA; (2) stimulation of a faster response to the imposed field by PMA; and (3) inhibition of the directed translocation by 5 microM H-7. However, another PKC inhibitor, staurosporine, did not inhibit the directed translocation (1 nM-1 microM). We also found evidence for the involvement of either cAMP- or cGMP-dependent protein kinase. The galvanotactic response was partially inhibited by the addition of 10 microM H-9 and the response was enhanced in the presence of the phosphodiesterase inhibitor, IBMX. However, the adenylate cyclase stimulant, forskolin, had no significant influence on the directed motility, although it reduced the average cell velocity. While these experiments suggest that cAMP- or cGMP-dependent protein kinase or PKC may be involved in the galvanotaxis response, two other protein kinases appeared not to be required. The myosin light chain kinase inhibitor, ML-7, had no effect on the directed motility in an imposed field, so myosin light chain kinase may not be required for galvanotaxis. Similarly, 5 microM W-7 had no significant effect on the directed translocation, suggesting that calmodulin-dependent protein kinase is not involved. Interestingly, the continuous activity of a protein kinase is apparently not required for the directed translocation response. The addition of the PKC and cAMP-dependent protein kinase inhibitor, H-7, after the cells had been exposed to the field for 1 hour, had no effect on the subsequent directed translocation. Thus, for these inhibitors to block the directed translocation, they must be present at the same time as the initial field application. This implies that an integral step in the cellular response mechanism for galvanotaxis involves the stimulation of a protein kinase whose effect is long lasting.

Animals↗
PubMed1993

Cervical collars: a potential risk to the head-injured patient.

Interface pressures beneath six types of collar in volunteers were measured. Under certain types of collar mean interface pressures of more than 10 mmHg were obtained, with several individual readings around 30 mmHg. By causing jugular venous obstruction a similar rise in intracranial pressure may be produced inadvertently. The mechanisms of action for this are discussed. Those collars with the least tendency to produce jugular venous obstruction were of the moulded variety which extend support to the occiput, mandible and shoulder girdle. The authors therefore recommend this type of cervical splintage device where injury of the cervical spine is suspected. This paper emphasizes the potential danger to head-injured patients when the other devices are applied too tightly, producing a 'venous tourniquet' effect.

Craniocerebral Trauma↗
PubMed1993

Occult spinal cord injury in traumatized children.

The existence of spinal cord injury without radiological abnormality (SCIWORA) has been recognized for some years. Two cases of SCIWORA in children are presented which highlight the possibility of severe spinal cord injury without any physical or radiological signs. The injury may occur at any level. It is recommended that normal procedures used for spinal immobilization in adults are inappropriate in the case of children and all unconscious children should be treated with full spinal immobilization until clinical assessment of neurological function is possible.

Accidents, Traffic↗
PubMed1993

Narrow-band (TL-01) UVB air-conditioned phototherapy for chronic severe adult atopic dermatitis.

In an open study of 21 severely affected adult atopic dermatitis patients, air-conditioned narrow-band UVB phototherapy using the Philips TL-01 lamp three times weekly for 12 weeks resulted in a 68% reduction in atopic dermatitis severity scores, with a concomitant 88% reduction in potent topical steroid use. Follow-up at 24 weeks revealed that six patients had relapsed to > 70% of pre-phototherapy severity scores; the remaining 15 continued to derive long-term benefit. The mean value of potent topical steroid use remained 50% below pre-phototherapy needs. Narrow-band UVB (TL-01) phototherapy appears an effective, steroid-sparing treatment for chronic severe atopic dermatitis, offering long-term benefits in the majority of those treated.

Adult↗
PubMed1993

The suitability of SunCheck patches and Tanscan cards for monitoring the sunburning effectiveness of sunlight.

UV-sensitive products which undergo a colour change on exposure to UV radiation are available for use by the general public. We have evaluated SunCheck patches of various sensitivities, and Tanscan UV sensor cards, in terms of their temperature stability, wavelength response and response to sunlight. The products exhibited no perceptible colour change when the temperature was maintained at 45 degrees C for 4 hours; on exposure to monochromatic radiation, the sensitivity peaked at a wavelength of 335 and 355 nm for SunCheck and Tanscan, respectively; the response to sunlight under clear conditions was reasonably consistent, with the coefficient of variation for each type of material ranging between 12.5 and 27%. These products are based on the incorrect concept that there is a 'safe' dose of UV radiation. Thus, they cannot be recommended to the public as a reliable way of reducing the risk of skin cancer.

Dermatology↗
PubMed1993

Clinical and laboratory studies of the photosensitizing potential of norfloxacin, a 4-quinolone broad-spectrum antibiotic.

Cutaneous photosensitivity reactions are a consistent although uncommon feature of the fluoroquinolone group of antibiotics, which are related to nalidixic acid. Objective laboratory and clinical data are now routinely required by regulatory bodies for new drugs suspected of being photosensitizers, but no clear recommendations exist. A series of in vitro tests ranging in complexity revealed a UVA-dependent phototoxic potential for the fluoroquinolone norfloxacin similar to that for ciprofloxacin, and less than that of nalidixic acid. Controlled monochromator phototesting, designed to reveal the clinical characteristics, wavelength dependence and severity of cutaneous reactions in normal subjects showed both norfloxacin and ciprofloxacin to have a weak phototoxic potential which clears within 4 weeks of stopping the drug. UVA wavelengths (335 +/- 30 nm; 365 +/- 30 nm) appear most responsible for producing an asymptomatic erythema which is maximal at 24 h. The clinical study differs from those used previously in being blind, containing positive and negative controls, and phototesting after cessation of drug intake. The methodology has the anticipated limitation of failing to detect idiosyncratic photosensitivity responses.

Adolescent↗
PubMed1993

Failure of coconut oil to accelerate psoriasis clearance in narrow-band UVB phototherapy or photochemotherapy.

Despite a widely held belief that the use of emollients prior to broad-band UVB irradiation accelerates clearance of psoriasis, only one single-blind controlled study exists in support of this. No similar study has been carried out with photochemotherapy (PUVA) or narrow-band UVB (311-313 nm) phototherapy. As some emollients absorb UV radiation, and thereby inhibit psoriasis clearance, there is a need to identify emollients suitable for pre-irradiation use. Coconut oil may be useful in this respect. In two randomized groups of patients with chronic plaque psoriasis undergoing either routine PUVA (n = 14) or narrow-band UVB phototherapy (n = 15), a single-blind controlled (half-body) study was undertaken to assess the effect of pre-irradiation application of coconut oil. Patients were given PUVA twice weekly, or TL-01 therapy thrice weekly. The initial UV dose was 70% of previously determined minimal phototoxic (MPD) or minimal erythema doses (MED), with 40% incremental steps at each visit (reduced if adverse effects occurred). Psoriasis severity was scored on each side after every three treatments. No significant acceleration of psoriasis clearance was seen in either group. We do not, therefore, recommend the routine use of emollients prior to PUVA or TL-01 therapy when using near erythemogenic irradiation regimens.

Adolescent↗
PubMed1993

Photodistributed nifedipine-induced facial telangiectasia.

Five months after starting nifedipine (Adalat), two patients developed photodistributed facial telangiectasia, which became more noticeable with time. Neither patient complained of photosensitivity or flushing. Both patients reported a significant cosmetic improvement after discontinuing the drug. One commenced the closely related drug amlodipine 3 years later, with recurrence of telangiectasia. The photodistribution of the telangiectasia suggests a significant drug/light interaction.

Adult↗
PubMed1993

A comparison of narrow band phototherapy (TL-01) and photochemotherapy (PUVA) in the management of polymorphic light eruption.

Twenty-five patients suffering from severe polymorphic light eruption (PLE) were randomized to either photochemotherapy (PUVA) or narrow-band phototherapy (TL-01 UVB) treatment in early spring; patients receiving UVB were given placebo tablets to achieve a matching therapy procedure. During the 4 months following treatment, patient exposure to solar UVB was monitored with polysulphone badges. PLE occurrence, severity, and restriction of outdoor activity were recorded, using weekly diary-sheets. Analysis of covariance on this data, using the logarithm of UVB exposure as the explanatory variable, showed no significant differences between the treatments. TL-01 UVB is an effective alternative to PUVA in the management of PLE.

Adult↗
PubMed1993

A trial of accelerated PUVA in psoriasis.

Ten psoriatic patients were treated with an accelerated PUVA regimen. Nine patients cleared in an average of 13.7 treatments (range 4-24) after an average total UVA dose of 83 J/cm2 (range 18-186). One patient had to withdraw due to pruritus and burning and six others had burning problems. The high incidence of burning may limit the routine use of this irradiation regimen.

Female↗