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Biomedical subjects

A Herrick

Publications and source records attributed to A Herrick.

15 recordsLinked to original sources
PubMed2004

Assessment of endothelial function in complex regional pain syndrome type I using iontophoresis and laser Doppler imaging.

OBJECTIVES: To assess microvascular endothelial function in patients with complex regional pain syndrome type I (CRPS) compared with healthy controls, as measured by iontophoresis of vasoactive chemicals and laser Doppler imaging. METHODS: Microvascular blood flow was stimulated locally in affected and contralateral limbs of patients with CRPS (n = 17) and in control subjects (n = 16) using iontophoresis of the endothelial-dependent vasodilator acetylcholine (ACh) and the endothelial-independent vasodilator sodium nitroprusside (NaNP). Changes in blood flow were measured using laser Doppler imaging. Comparisons were made between right and left limbs and between patients and controls. RESULTS: No significant differences in blood flow [expressed as a median percentage increase from baseline (interquartile range)] were detected between affected and contralateral limbs in patients with CRPS for ACh [affected 237 (95-344); unaffected 251 (152-273)] or for NaNP [affected 102 (49-300); unaffected 190 (53-218)]. In addition, there were no significant differences between patients and healthy controls [controls, ACh 216 (119-316); controls, NaNP: 122 (48-249)]. CONCLUSIONS: In this pilot study, CRPS was not associated with impairment of microvascular endothelial function. This may be a true result or may reflect the diversity of the CRPS disease process.

Acetylcholine↗
PubMed2004

Digital ulcers in systemic sclerosis: prevention by treatment with bosentan, an oral endothelin receptor antagonist.

OBJECTIVE: Recurrent digital ulcers are a manifestation of vascular disease in patients with systemic sclerosis (SSc; scleroderma) and lead to pain, impaired function, and tissue loss. We investigated whether treatment with the endothelin receptor antagonist, bosentan, decreased the development of new digital ulcers in patients with SSc. METHODS: This was a randomized, prospective, placebo-controlled, double-blind study of 122 patients at 17 centers in Europe and North America, evaluating the effect of treatment on prevention of digital ulcers. The primary outcome variable was the number of new digital ulcers developing during the 16-week study period. Secondary assessments included healing of existing digital ulcers and evaluation of hand function using the Scleroderma Health Assessment Questionnaire. RESULTS: Patients receiving bosentan had a 48% reduction in the mean number of new ulcers during the treatment period (1.4 versus 2.7 new ulcers; P = 0.0083). Patients who had digital ulcers at the time of entry in the study were at higher risk for the development of new ulcers; in this subgroup the mean number of new ulcers was reduced from 3.6 to 1.8 (P = 0.0075). In patients receiving bosentan, a statistically significant improvement in hand function was observed. There was no difference between treatment groups in the healing of existing ulcers. Serum transaminase levels were elevated to >3-fold the upper limit of normal in bosentan-treated patients; this elevation is comparable with that observed in previous studies of this agent. Other side effects were similar in the 2 treatment groups. CONCLUSION: Endothelins may play an important role in the pathogenesis of vascular disease in patients with SSc. Treatment with the endothelin receptor antagonist bosentan may be effective in preventing new digital ulcers and improving hand function in patients with SSc.

Activities of Daily Living↗
PubMed2001

Lack of relationship between functional ability and skin score in patients with systemic sclerosis.

OBJECTIVE: To examine the hypothesis that functional ability is related to skin score in patients with systemic sclerosis (SSc). METHODS: In 140 patients with SSc attending clinics in the northwestern region of England, functional ability (measured using a recently developed 11 item functional questionnaire) was correlated with skin score (measured using a modified Rodnan technique--17 sites, maximum score 3 for each site). RESULTS: The median functional score was 6 (range 0-31) and the median skin score 7 (range 0-37). There was no correlation between functional score and total skin score (rS = 0.11, p = 0.19, Spearman). Because most of the questions of the functional score related to upper limb function, separate analyses were undertaken restricting consideration of skin involvement to (1) upper limbs only and (2) digital skin only, versus the overall functional score. Again, no evidence of an association was observed. CONCLUSION: Functional ability in this broad group of patients with SSc cannot be predicted from the skin score. Although skin score is useful prognostically, it is not a major determinant of a patient's ability to perform activities of everyday living.

Adult↗
PubMed2000

Association of markers for TGFbeta3, TGFbeta2 and TIMP1 with systemic sclerosis.

OBJECTIVES: To investigate whether six microsatellite markers known to map closely to genes involved in fibrosis are associated with systemic sclerosis (SSc). METHODS: Markers mapping to TGFbeta1, TGFbeta2, TGFbeta3, PDGFB, TIMP1 and COL5A2 were genotyped and allele frequency distributions compared in 191 patients and 196 controls. As TIMP1 maps to the X chromosome, male and females were analysed separately. Markers associated with SSc were further investigated according to whether patients had limited (lcSSc) or diffuse (dcSSc) cutaneous fibrosis. RESULTS: Associations were found between SSc and markers for TGFbeta3 (chi(2)=17.3, df=8, P=0.02), TGFbeta2 (chi(2)=25.2, df=13, P=0.02) and TIMP1 (with male SSc, chi(2)=11.9, df=5, P=0.03), between lcSSc and the TGFss2 marker (chi(2)=25.6, df=13, P=0.02), and between dcSSc and TGFbeta3 marker (chi(2)=27.1, df=8, P=0.001). Between lcSSc and dcSSc patients, the allele frequency distribution differed only for the TGFbeta3 marker (chi(2)=16.5, df=6, P=0.01). CONCLUSION: These associations indicate a possible role for TGFbeta3, TGFbeta2 and TIMP1 in genetic susceptibility to SSc and for TGFbeta3 in determining the degree of cutaneous fibrosis.

Adult↗
PubMed1999

The "distal-dorsal difference" as a possible predictor of secondary Raynaud's phenomenon.

OBJECTIVE: To investigate the possibility that a hand distal-dorsal difference in temperature of greater than 1 degree C (fingers colder than the dorsum) at a room temperature of 30 degrees C is a good predictor of secondary Raynaud's phenomenon (RP). METHODS: We imaged the hands of patients with primary Raynaud's phenomenon (PRP) and systemic sclerosis (SSc) using a thermal camera at room temperatures of 23 and 30 degrees C. From these images we measured the distal-dorsal difference in temperature for all fingers excluding the thumbs. At a room temperature of 23 degrees C we also performed a cold challenge test using water at 15 degrees C for 1 min and thermally imaged the rewarming process for 15 min. Several variables were derived from the rewarming curve. The procedure was repeated within 3 days to assess reproducibility. RESULTS: The best discriminator between PRP and SSc was found to be a distal-dorsal difference of > 1 degree C at 30 degrees C (p = 0.005). There is reasonable reproducibility when considering groups of patients. However, the intra-subject standard deviations were large, indicating that measurements for the same patient on separate visits may vary considerably. CONCLUSION: Our results suggest that the finding of a distal-dorsal difference of > 1 degree C (cold fingers) at 30 degrees C in a patient with RP is specific for underlying connective tissue disease.

Adolescent↗
PubMed1996

Soluble L-selectin in the connective tissue diseases.

Plasma levels of the leucocyte adhesion molecule L-selectin were measured by ELISA in 41 patients with rheumatoid arthritis, 18 with ankylosing spondylitis, 18 with systemic sclerosis and 27 with vasculitis together with 42 age- and sex-matched controls. Low levels of soluble L-selectin were found in systemic sclerosis (797 +/- 302 ng/ml, P < 0.05) and vasculitis (941 +/- 329 ng/ml, P < 0.05) relative to controls (1244 +/- 269 ng/ml). The exact reasons for low levels of soluble L-selectin are unclear, but may reflect reduced shedding from leucocytes and/or strong binding to its cell membrane ligand(s). An approximate inverse relationship between soluble L-selectin and disease severity may have clinical relevance.

Adult↗
PubMed1995

Altered levels of soluble adhesion molecules in rheumatoid arthritis, vasculitis and systemic sclerosis.

We compared the levels of soluble adhesion molecules E-selectin (sE-selectin), intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) alongside von Willebrand factor (vWf), CRP and rheumatoid factor in 40 patients in serum by ELISA, rheumatoid factor by sheep red blood cell agglutination and CRP by immunonephelometry. Compared to controls, increased sE-selectin was found in patients with RA (P = 0.0015), vasculitis (P < 0.0003) and SSc (P = 0.0126), whilst raised sICAM-1 was found in RA (P < 0.0003), vasculitis (P < 0.0003) and SSc (P < 0.0378). sVCAM was lower in RA than in controls (P = 0.0102), but was unchanged in vasculitis or in SSc. vWF was raised in RA (P = 0.0102), vasculitis (P < 0.0003) and SSc (P < 0.0003). In a Spearman's rank analysis of all the data, vWf correlated with sVCAM-1 and sICAM-1 (both P < 0.001), sE-selectin with sICAM-1 (P < 0.001) and sVCAM with sICAM-1 (P < 0.005). Levels of rheumatoid factor correlated with those of sE-selectin (P = 0.003) and sVCAM-1 (P = 0.012), but there were no correlations between any index and CRP. The strongest correlations within the RA group were between sICAM and sVCAM (P = 0.001), in vasculitis it was between sE-selectin and sICAM (P < 0.001), and in SSc it was between sE-selectin and sVCAM (P = 0.019). These data suggest that the differing levels of vWf, sE-selectin and sICAM-1 in the inflammatory vasculitides may be useful in establishing a role for leucocyte/endothelial adhesion in these diseases.

Adult↗
PubMed1994

Plasma TGF beta in systemic sclerosis: a cross-sectional study.

OBJECTIVES: To determine whether the active 25 kDa form of the fibrogenic cytokine transforming growth factor beta (TGF beta) can be detected in plasma from patients with systemic sclerosis and to examine the relationship between plasma TGF beta and clinical markers of disease severity and serum concentrations of the aminoterminal peptide of type III procollagen (PIIINP) (a laboratory marker of the fibrotic process). METHODS: A cross sectional study was made of 39 patients with systemic sclerosis (11 diffuse and 28 limited), nine patients with primary Raynaud's disease and 60 healthy controls. TGF beta 1 and TGF beta 2 were measured by enzyme linked immunosorbent assay (ELISA) (sensitivity 100 pg/ml) and PIIINP by radioimmunoassay. RESULTS: TGF beta 1 was detected in plasma from six of 39 patients with systemic sclerosis but not in any patient with primary Raynaud's disease or healthy controls. TGF beta 2 was not detected in plasma from patients or controls. No clear relationship was demonstrated between TGF beta 1, clinical features or PIIINP concentrations. CONCLUSIONS: The 25 kDa form of TGF beta 1 can be detected in the plasma of some patients with systemic sclerosis. This provides limited support for the hypothesis that this cytokine plays a role in the pathogenesis of this disease. However, longitudinal studies, particularly in early diffuse disease, are required to clarify the relationship between circulating TGF beta 1 and disease activity.

Adult↗
PubMed1994

Abnormal thermoregulatory responses in patients with reflex sympathetic dystrophy syndrome.

OBJECTIVE: To look for asymptomatic thermoregulatory abnormalities in the noninvolved limbs in patients with well established reflex sympathetic dystrophy syndrome (RSDS). The study was prompted by the observation of development of severe upper limb Raynaud's phenomenon in a young woman with a history of RSDS affecting both lower limbs. METHODS: Eleven patients and 11 age and sex matched control subjects underwent a standard thermal stress test: cold water immersion of a hand unaffected by RSDS in water at 15 degrees C for one min. All controls had had injuries uncomplicated by RSDS. RESULTS: Lag time (the lag phase between the end of the cold challenge and the onset of rewarming) was significantly increased (p < 0.01) in the patient group (median 5.67 min, range 0.50 to > 15) compared to the control group (median 0.50 min, range 0.50 to 12.92). The median maximum temperature recovery was lower in the patient group (81.6%, range 0 to 170.4) than in the control group (119.3%, range 49.1 to 153.1). CONCLUSION: Our findings support an association between RSDS and a generalized abnormal response to cold challenge. Further studies are required to examine the temporal relationship underlying this. Early screening for thermoregulatory dysfunction of patients after fractures might allow identification of patients at risk of developing RSDS.

Adolescent↗
PubMed1987

Effect of haem arginate therapy on porphyrin metabolism and mixed function oxygenase activity in acute hepatic porphyria.

The effect of haem arginate on porphyrin metabolism and haemoprotein function was studied during seven attacks of acute hepatic porphyria in 5 patients. In each attack it greatly reduced the overproduction of porphyrin precursors and repressed the overactivity of the rate-controlling enzyme of haem synthesis delta-aminolaevulinic acid (ALA) synthase measured in leucocytes. Antipyrine clearance, an index of the oxidative function of cytochromes P-450, the major group of hepatic haemoproteins, was increased during haem therapy. Thus, haem arginate not only suppresses the overproduction of haem precursors but also improves hepatic oxidative metabolism in acute porphyria.

Acute Disease↗
PubMedDate not supplied

A randomised, double-blind study of cicaprost, an oral prostacyclin analogue, in the treatment of Raynaud's phenomenon secondary to systemic sclerosis.

Cicaprost is a new synthetic prostacylin analogue which is metabolically stable and bioavailable after oral administration; in previous studies it has been shown to have vasodilator antiplatelet effects. In this pilot study, we investigated the clinical efficacy of and patient tolerance to two dosage levels of cicaprost (2.5 micrograms tds and 5 micrograms tds) in the treatment of Raynaud's phenomenon secondary to systemic sclerosis (SSc). This was a three centre, double-blind, placebo controlled study of 49 patients carried out over four winter months. For a period of 10 days, 16 patients were given a placebo, 16 received cicaprost 2.5 micrograms tds and 17 received cicaprost 5 micrograms tds. Response was assessed based on the total number and duration of Raynaud's attacks, the average severity of the attacks, the number of painful attacks as a proportion of all attacks, a digital ulcer count, and the patients' opinion of the treatment. Although the clinical and laboratory parameters of digital vasospasm did not show statistically significant improvement in those who received cicaprost compared with those on the placebo, the severity of attacks lessened in the patients who received cicaprost 5 micrograms tds, and a statistically significant difference was seen in the average severity at week 2 post-treatment (p = 0.02). The apparent lack of overall significance was probably related to the short treatment period and relatively low doses of cicaprost used in this exploratory study. Longer studies with dose titration are probably needed to demonstrate the beneficial effects, if any, of cicaprost in patients with Raynaud's secondary to SSc, and these are being planned.

Administration, Oral↗