Biomedical subjects
J Ferguson
Publications and source records attributed to J Ferguson.
Letter: Arthritis, uveitis, and HL-A 27.
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Pigmentary disorders and systemic drug therapy.
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Use of flyash as environmental and agronomic amendments.
Coal combustion power plant flyash materials have been reported as useful soil amendments with agronomic and environmental benefits. This paper reports the efficacy of fluidized bed combustion (FBC) and flue gas desulfurization (FGD) byproducts, when amended with dairy, swine, and broiler litter manures, in reducing phosphorus (P) solubility and potential impact on water quality. At a rate of 400 g/kg, FBC reduced water soluble P by 60% for dairy and swine and 50% for broiler litter, as compared to un-treated control samples. Byproduct FGD had little effect when amended into dairy manure, but reduced water soluble P by nearly 80% when amended into swine and broiler manure at a rate of 250 g/kg. The amount of Ca added in the amendments together with pH of the mixture is the major contributing factor in soluble P reduction. Sequential extraction results showed that the flyash treatments shifted water soluble P into mainly bicarbonate extractable P. The latter is still considered available for crop uptake but less vulnerable for environmental losses. Coal combustion byproducts, when amended into manure and used properly, can provide a useful and viable option for improving nutrient management on animal farms.
Can a positive photopatch test be elicited by subclinical irritancy or allergy plus suberythemal UV exposure?
Photopatch test (PhPT) interpretation is difficult and clinical relevance is not always apparent. A positive PhPT may reflect photocontact allergy or phototoxicity. We hypothesized that it may also reflect the additive or synergistic effects of a suberythemal reaction to a contact irritant [e.g. sodium lauryl sulfate (SLS)] or allergen (e.g. nickel) and suberythemal UV exposure. 10 nickel allergic volunteers had duplicate SLS and nickel series applied on either side of the back for 24 h and 48 h, respectively. After removal, one side was irradiated with 5 J/cm(2) UVA or the dose below the minimal erythema dose for solar-simulated radiation (SSR). The minimal irritancy dose (MID) for SLS and the minimal allergenic dose (MAD) for nickel were determined visually and objectively by erythema meter. While photoaugmentation of subclinical contact allergy or irritancy occurred in some subjects, photosuppression occurred in roughly an equal number. UVA changed the nickel MAD at 48 h in 2 of 5 volunteers but not the SLS MID. SSR changed the nickel MAD in 4 of 5 and the SLS MID in 3 of 5. 2 subjects (none after UVA) showed erythema only in the irradiated set of patches, which could have been interpreted as a positive PhPT. We have demonstrated photoaugmentation and photosuppression of contact allergy and irritancy, which could result in false-positive or false-negative interpretation of PhPTs.
Nonhemolytic febrile transfusion reactions. Quantitative effects of blood components with emphasis on isoantigenic incompatibility of leukocytes.
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Bath PUVA--an investigation of the distribution of trioxsalen (TMP) and 8-methoxypsoralen (8-MOP) in bathwater.
Trioxsalen (TMP) bath PUVA avoids the side effects of nausea and headache associated with oral 8-methoxypsoralen (8-MOP) treatment and allows shorter irradiation times that can be advantageous in some patients. However we noted that a number of patients developed unusual patterns of phototoxic burning. We thought that this was related to an uneven distribution of the TMP in the bathwater and for this reason, a study of bath water TMP concentrations achieved using different TMP preparations was undertaken. The distribution of 8-MOP in an 8-MOP bath was also measured for comparison. Our results confirm that an uneven distribution of TMP is achieved using TMP capsules or suspension and would explain our observed patterns of burning. With an ethanolic solution of TMP, or the commercial equivalent Tripsor, or with Puvasoralen-8 (an 8-MOP preparation), a homogeneous psoralen distribution is achieved, and they are therefore preferable for use in bath PUVA.
Artificial hardening for polymorphic light eruption: practical points from ten years' experience.
The conservative approach of sunlight avoidance and broad-spectrum sunscreen is often disappointing in patients with moderate to severe polymorphic light eruption. A springtime course of prophylactic artificial hardening with ultraviolet B (UVB) phototherapy or psoralen plus ultraviolet A (PUVA) photochemotherapy will often allow patients to tolerate more sunlight and give them greater freedom during the summer. In this retrospective study we describe ten years' experience of such "desensitization" treatment. Individualized therapy with attention to detail will maximize the effectiveness of this treatment.
Evaluation of phototoxic potential of gemifloxacin in healthy volunteers compared with ciprofloxacin.
This double-blind, randomized, parallel-group comparative study investigated the phototoxic potential of gemifloxacin mesylate, a potent, novel fluoroquinolone antimicrobial. Forty healthy male and female volunteers received repeat dosing for 7 days with 160 mg or 320 mg of gemifloxacin (o.d., p.m.), 500 mg of ciprofloxacin (b.d.) or placebo (b.d.). On day 5 (large step) and day 6 (small step), graded series of wavebands were irradiated onto the back of each volunteer (phototesting). Skin reactions were assessed 0-30 min (immediate erythema) and 24 and 48 h (delayed erythema) after irradiation. Both gemifloxacin, 320 mg o.d., and ciprofloxacin, 500 mg b.d., were associated with mild phototoxicity following 7 days of administration. The range of mean phototoxic indices (the ratio of minimal erythemal dose at baseline compared with that on day 7 at the end of dosing) was 1.00-2.19 for gemifloxacin and 0.97-2.23 for ciprofloxacin. The abnormal responses occurred within the ultraviolet A region (335-365 +/-30 nm) and were maximal at 24 h. Susceptibility to phototoxicity had cleared 48 h after stopping the drug. The phototoxicity observed with gemifloxacin, 160 mg o.d., was lower than that at the higher dose and similar to that of placebo, suggesting that gemifloxacin phototoxicity is dose dependent. There were no clinically important changes in the safety profiles of gemifloxacin and ciprofloxacin compared with placebo in healthy volunteers after 7 days of repeat dosing. This study demonstrated that gemifloxacin, 320 mg o.d. given for 7 days, has a low potential to cause mild photosensitivity which is similar to that of ciprofloxacin, 500 mg b.d., given for the same period.
Early spica treatment of pediatric femoral shaft fractures.
The purpose of this prospective study was to document results of early spica casting in treating all children aged 10 years or younger presenting during a 30-month period with a femoral shaft fracture. The outcome of 101 femoral shaft fractures thus treated demonstrated excellent results with few complications. Four spicas had to be removed at 7 to 10 days for unacceptable shortening and an additional four probably should have been. Control of alignment was not a problem, with only one patient's femur on cast removal being in a position different from that accepted at 7 to 10 days. An age older than 7 to 8 years is the only variable that might be used to predict the need for a change in treatment at 7 to 10 days.
Radiation from ultraviolet phototherapy sources results in photodegradation of 12(R) and 12(S)-hydroxy-eicosatetraenoic acid: high-performance liquid chromatography and polymorph migration studies.
The effect of irradiation from Sylvania PUVA lamps (emitting predominantly in the ultraviolet (UVA) region) and broadband Philips TL-12 lamps (peaking in the UVB region) on two inflammatory mediators, 12(R)- and 12(S)-hydroxy-eicosatetraenoic acid (HETE) was studied. A high-performance liquid chromatography study showed significant photodegradation of both enantiomers at a concentration of 5 micrograms/ml in phosphate-buffered saline following irradiation with 10 J.cm-2 UVA or 0.375 J.cm-2 UVB. The in vitro chemokinetic microdroplet migration response of human peripheral polymorphonuclear leukocytes from normal and psoriatic subjects was significantly reduced following irradiation of 12(R)-HETE at a concentration of 1 micrograms/ml in medium with 40 J.cm-2 UVA and 1.5 J.cm-2 UVB respectively. No such effect was seen with 12(S)-HETE. The effect of ultraviolet on skin physiology, and in particular in the successful phototherapy of a range of inflammatory skin disorders, is not fully understood. The photodegradation of inflammatory mediators such as 12-HETE, as shown in this study, provides another factor of possible therapeutic significance.
Cutaneous vasculitis secondary to ramipril.
A 61-year-old patient who had been treated with lisinopril in the past without any problems was commenced on ramipril for left ventricular dysfunction. He developed a painful symmetrical purpuric eruption over both feet after three days. A full vasculitis screen was negative. Ramipril was stopped and he required a course of steroids after which the rash improved slowly. The ACE inhibitors can cause various skin side effects; however, it rarely causes cutaneous vasculitis. Ramipril-induced cutaneous vasculitis is particularly rare and our case was atypical because the patient had tolerated lisinopril before. Previous successful treatment with one ACE inhibitor does not rule out the vasculitis caused by the drug from the same group. Here we report ramipril-induced cutaneous vasculitis in a patient who required steroid therapy to control it.
The antiarrhythmic effect of the ACE inhibitor captopril in patients with congestive heart failure largely is due to its potassium sparing effects.
OBJECTIVE: To evaluate the mechanisms by which the angiotensin converting enzyme (ACE) inhibitor captopril may modify the presence of ventricular arrhythmias in patients with chronic heart failure. PATIENTS: Forty-seven patients with chronic stable congestive heart failure. METHODS: Twenty-four hour Holter monitoring was done prior to and after one month of therapy with the ACE inhibitor captopril. In a first group of 25 patients, changes in the incidence of ventricular arrhythmias were correlated with changes in cardiac hemodynamics (assessed invasively). In a second group of 22 patients, changes in ventricular arrhythmias were correlated with changes in echocardiographic measurements. In all patients serum potassium was kept constant, and changes in exercise tolerance and serum noradrenaline levels were assessed prior to and after captopril. RESULTS: One month of captopril therapy caused an improvement in cardiac hemodynamics and in exercise tolerance. It also led to a tendency for improved echocardiographic measurements and serum noradrenaline levels, similar to those already published by others. However, no change in the incidence or severity of ventricular arrhythmias was detected. No correlation could be found between changes in ventricular arrhythmias and any of the variables measured. CONCLUSIONS: As the only obvious difference between this and previous studies that documented a decrease in ventricular arrhythmias when ACE inhibitors were started in patients with congestive heart failure is a lack of change in serum potassium in this study, the current results suggest that the major antiarrhythmic effect of ACE inhibitors in patients with congestive hear failure is the result of their potassium sparing effects.
Reflections of a pupil nurse: the end of the beginning or the beginning of the end.
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Managed care and nurses' roles.
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