An open, multicentre, randomized clinical study in patients with bullous pemphigoid comparing methylprednisolone and azathioprine with methylprednisolone and dapsone.

BACKGROUND: Current treatment of bullous pemphigoid (BP) is based on the long-term use of topical and/or systemic corticosteroids, which are associated with a high rate of adverse events and increased mortality. OBJECTIVES: To study the corticosteroid-sparing potential of azathioprine and dapsone. METHODS: This was a prospective, multicentre, randomized, nonblinded clinical trial that compared the efficacy and safety of two parallel groups of patients with BP treated with oral methylprednisolone 0·5 mg kg-1 per day in combination with either azathioprine 1·5-2·5 mg kg-1 per day or dapsone 1·5 mg kg-1 per day. Nine German and Austrian departments of dermatology included 54 patients based on clinical lesions, positive direct immunofluorescence (IF) microscopy and detection of serum autoantibodies by indirect IF microscopy, immunoblotting or enzyme-linked immunosorbent assay. The primary end point was the time until complete tapering of methylprednisolone, and the most important secondary end point was the cumulative corticosteroid dose. RESULTS: In eight patients (five azathioprine, three dapsone), methylprednisolone could be discontinued after a median time of 251 days in the azathioprine group and 81 days in the dapsone group. The median cumulative corticosteroid dose was 2·65 g for azathioprine compared with 1·92 g for dapsone (P = 0·06). The median numbers of days when corticosteroids were applied were 148 and 51, respectively (P = 0·24). No significant difference in the number of adverse events was seen between the treatment arms. Four patients (8%) died within the observation period of 12 months. CONCLUSIONS: Due to the lower than intended number of patients, the results of the primary and secondary end points were not or only barely significant. Dapsone appeared to have a moderately higher corticosteroid-sparing potential than azathioprine. The combination regimen of either drug with oral methylprednisolone is associated with a relatively low 1-year mortality in this vulnerable patient population.

A map of local adaptation in Arabidopsis thaliana.

Local adaptation is critical for species persistence in the face of rapid environmental change, but its genetic basis is not well understood. Growing the model plant Arabidopsis thaliana in field experiments in four sites across the species' native range, we identified candidate loci for local adaptation from a genome-wide association study of lifetime fitness in geographically diverse accessions. Fitness-associated loci exhibited both geographic and climatic signatures of local adaptation. Relative to genomic controls, high-fitness alleles were generally distributed closer to the site where they increased fitness, occupying specific and distinct climate spaces. Independent loci with different molecular functions contributed most strongly to fitness variation in each site. Independent local adaptation by distinct genetic mechanisms may facilitate a flexible evolutionary response to changing environment across a species range.

Genetic and physiological bases for phenological responses to current and predicted climates.

We are now reaching the stage at which specific genetic factors with known physiological effects can be tied directly and quantitatively to variation in phenology. With such a mechanistic understanding, scientists can better predict phenological responses to novel seasonal climates. Using the widespread model species Arabidopsis thaliana, we explore how variation in different genetic pathways can be linked to phenology and life-history variation across geographical regions and seasons. We show that the expression of phenological traits including flowering depends critically on the growth season, and we outline an integrated life-history approach to phenology in which the timing of later life-history events can be contingent on the environmental cues regulating earlier life stages. As flowering time in many plants is determined by the integration of multiple environmentally sensitive gene pathways, the novel combinations of important seasonal cues in projected future climates will alter how phenology responds to variation in the flowering time gene network with important consequences for plant life history. We discuss how phenology models in other systems--both natural and agricultural--could employ a similar framework to explore the potential contribution of genetic variation to the physiological integration of cues determining phenology.

Penicillin G does not alter collagen type I metabolism of dermal fibroblasts in culture.

BACKGROUND: Penicillin G (PenG) has successfully been used for therapy of dermal fibrosis in patients suffering from systemic sclerosis (SSc). However, there is little knowledge on the mechanism of the antifibrotic action of PenG. OBJECTIVE: We studied the effects of PenG on dermal fibroblasts by analysing the influence of various amounts of PenG on the proliferation, synthesis and degradation of collagen by human dermal fibroblasts from healthy donors and 1 SSc patient (collagen high producer). METHODS: Collagen metabolism of cultured dermal fibroblasts was studied by Northern hybridisation for mRNA of collagen I, proline-4-hydroxylase, lysyl hydroxylase, matrix metalloproteinase I and determination of collagen content in culture supernatants. RESULTS: PenG did not alter the expression of the investigated mRNA, independently of the dosage and the incubation times used. The amount of collagen I protein was not influenced. CONCLUSION: There is no evidence of a direct antifibrotic effect of PenG on dermal fibroblasts; therefore, other mechanisms might be responsible for its effect in the treatment of SSc patients.

Physiological response to complex environments in annual Polygonum species of contrasting ecological breadth.

Individual physiological response to complex environments is a major factor in the ecological breadth of species. This study compared individual patterns of both long-term and short-term response to controlled, multifactorial environments in four annual Polygonum species that differ in field distribution (P. cespitosum, P. hydropiper, P. lapathifolium, and P. persicaria). To test long-term response, instantaneous net photosynthetic rate and stomatal conductance were measured in situ on one full-sib replicate from five inbred lineages from each of five field populations per species, raised in all possible combinations of low or high light; dry, moist, or flooded soil; and poor or rich nutrient status. Short-term plastic adjustment to changes in light level was examined by switching individual plants of the four species from one of six multifactorial growth environments to the contrasting light environment, and measuring assimilation rates 1 h after transfer. The Polygonum species differed significantly in their patterns of long-term photosynthetic response to particular resources and resource combinations. The species known to have relatively broad ecological distributions (P. persicaria and P. lapathifolium) maintained high photosynthetic performance in a variety of moisture and nutrient environments when grown in high light, while the more narrowly distributed P. hydropiper maintained such functional levels only if given both high light and ample macronutrients. P. cespitosum, a species limited to shaded habitats, maintained low photosynthetic rates across the environmental range. Complex differences among the species in instantaneous water use efficiency (WUE) reflected their highly specific and to some extent independent patterns of photosynthetic and stomatal response to the multifactorial environments. The species also differed significantly in short-term physiological adjustment to changes in light level. Plants of P. persicaria and P. cespitosum reached 78% and 98%, respectively, of their maximum photosynthetic rates 1 h after transfer from low to high light, but P. hydropiper and P. lapathifolium plants reached only c. 60% of their maximum rates. When switched from high to low light, P. persicaria and P. cespitosum plants maintained 64-76% of their maximum rates, while P. hydropiper and P. lapathifolium plants decreased photosynthetic rates sharply to less than 50% of their maximum rates. These results indicate that the latter two species will be less able to maintain effective functional levels in variable light environments, a result consistent with their distributions in the field.

Symptoms and character traits in patients selected for long-term psychodynamic psychotherapy.

In this naturalistic study of 55 outpatients selected for long-term psychodynamic psychotherapy, two Swedish assessment instruments are presented (the Karolinska Psychodynamic Profile and the Karolinska Scales of Personality), and the significance of psychodynamic criteria for the selection of patients is discussed. Thirty patients (55%) fulfilled criteria for a DSM-III-R diagnosis. The most prominent psychodynamically defined character pathology was found in the areas of coping with aggressive affects; dependency and separation; frustration tolerance; and impulse control. Some psychodynamically defined character traits, particularly poor frustration tolerance, were related to symptomatic suffering.

Mouse fibroblast expressing human tyrosinase with DHICA-oxidase activity produces predominantly pheomelanin deposit in lysosome.

The melanogenic gene-transfected cell system serves as a useful tool for the study of the symphonic relation between melanin synthesis and intracellular organelles such as melanosomes in melanocytes. We constructed melanin-producing mouse fibroblasts by transfection of human tyrosinase cDNA to investigate the intracellular changes caused by tyrosinase expression. DHICA-oxidase (5,6-dihydroxyindole-2-carboxylic acid oxidase) activity without TRP-1 (Tyrosinase Related Protein-1) expression in the cells suggested that human tyrosinase also possesses a DHICA-oxidase activities different from mouse tyrosinase. Electron microscopic observation indicated that melanin-deposit organelles have some lysosomal features. These properties of melanin-deposit organelles in tyrosinase expressing fibroblasts provide one evidence for the hypothesis that melanosome is the specialized lysosome in melanocytes.

Composition of mammalian eumelanins: analyses of DHICA-derived units in pigments from hair and melanoma cells.

The proportions in which two eumelanin monomers, namely 5,6-dihydroxyindole-2-carboxylic acid (DHICA) and 5,6-dihydroxyindole (DHI), compose the eumelanin polymer are believed to determine properties of the pigment including its color. These proportions are, however, not well elucidated for naturally occurring eumelanins, largely because of methodological difficulties. In this study we estimate the content of DHICA-derived units in mammalian eumelanins using a combination of two analytical techniques: 1) quantitation of DHICA-derived eumelanin by measuring the yield of pyrrole-2,3,5-tricarboxylic acid (PTCA index) and 2) spectrophotometrical quantitation of total (DHI + DHICA) eumelanin at 350 nm (A350 index). The ratio of PTCA/A350 measured for melanins synthesized from DHI and DHICA mixed in various molar proportions correlates well with the content of DHICA in synthetic polymers. Using this relationship as a standard curve we estimated the proportion of DHICA-derived units in mammalian eumelanins from hair and melanoma cells and found it to be much higher in rodent pigments (58.8%-98.3%; two species, mouse and hamster were examined) as compared to human eumelanins (19.2%-41.8%; one Caucasian and one Oriental individual were examined). No relationship between proportion of DHICA-derived units in eumelanin and hair color is found. The latter seems to be determined predominantly by the ratio of pheo- to eumelanin synthesis.

Inhibitory effects of melanin monomers, dihydroxyindole-2-carboxylic acid (DHICA) and dihydroxyindole (DHI) on mammalian tyrosinase, with a special reference to the role of DHICA/DHI ratio in melanogenesis.

DOPAchrome tautomerase (DCT) is known to control the ratio of DHICA/DHI formed within the melanocyte, but physiologic significance of this activity is not yet fully elucidated. In this study the two melanin monomers are shown to inhibit with different efficacy the initial, tyrosinase-controlled, melanogenic reaction, namely conversion of L-tyrosine to DOPAchrome (2-carboxy-2,3-dihydroindole-5,6-quinone). This is demonstrated in the test tube assay system whereby formation of DOPAchrome is catalyzed by i) isolated premelanosomes (PMS), ii) tyrosinase-rich PMS glycoproteins, or iii) tyrosinase purified from fibroblasts transfected with human tyrosinase gene. Both DHI and DHICA suppress the conversion of L-tyrosine to DOPAchrome when added to reaction mixture but the inhibitory effect is far more strongly pronounced by DHI. DHI inhibits both activities of tyrosinase--tyrosine-hydroxylation and DOPA-oxidation--more strongly than DHICA. The different extent of inhibition is shown to reflect i) the ability of the two monomers to compete with tyrosinase substrates for the enzyme's active center and ii) the rate of interaction between melanin monomers and DOPAquinone. Consequently, we demonstrate that the tyrosinase-catalyzed DOPAchrome formation can be modulated by the ratio of DHICA/DHI among melanin monomers with the increased proportion of DHICA resulting in more efficient DOPAchrome formation. These results raise the possibility that DOPAchrome tautomerase plays a role in positive control of the tyrosinase-catalyzed early phase of melanogenesis.

Regulatory factors for polymerization of melanin monomers within coated vesicles and premelanosomes in melanoma cells.

Coated vesicles (CV) and premelanosomes (PMS) differ in the amount of melanin monomers produced from 2-carboxy-2,3-dihydroindole-5,6-quinone (dopachrome) in vitro. CV convert dopachrome preferentially to 5,6-dihydroxy-indole-2-carboxylic acid (DHI2C) and PMS mainly to 5,6-dihydroxyindole (DHI). We examined the effect of CV and PMS on in vitro spontaneous polymerization of DHI and DHI2C. The polymerization of DHI is accelerated by addition of extracts from both CV and PMS, while polymerization of DHI2C is suppressed. Factors associated with these two regulatory activities have been separated on concanavalin A-Sepharose. The ConA-adhesive glycoproteins isolated from PMS enhance polymerization of not only DHI but also DHI2C. The latter effect is stimulated by dopa. Both accelerating activities can be inhibited by phenylthiourea (PTU). In contrast to glycoproteins, the non-glycoprotein subfraction suppresses spontaneous polymerization of both melanin monomers. Our data suggest that the absence of in vivo melanin polymer formation within CV can be explained by formation by these organelles of relatively stable DHI2C rather than easily polymerizing DHI.

Electrophoretic heterogeneity of pigmented hamster melanoma cells.

Pigmented hamster melanoma tumors growing in situ contain two subpopulations of melanoma cells that have different electrophoretic mobilities (EPM). A mild neuraminidase treatment, which removes sialic acid residues from the cell surface glycoproteins, reduces the EPM of both groups of melanoma cells yielding an electrophoretically uniform population. This shows that the differences in the EPM between the subpopulations of pigmented melanoma cells stem from the different content of sialic acid residues on the cell surface. The relationship between the different EPM melanoma cell subpopulations was, therefore, examined during tumor growth, development, and formation of metastases. The relative content of cells having high electrophoretic mobility, the "fast moving" cells, increases as the tumors grow larger. However, tumors of the same diameter contain nearly the same fraction of "fast moving" cells despite their age. The proportion of the "fast moving" cells is significantly higher in the central part than in the outermost layer of pigmented melanoma tumors. These data suggest that the development of "fast moving" cells is promoted by some size-dependent changes in the intratumor environment. In vivo selection of melanoma cells for their ability to colonize lungs renders tumors that reveal elevated metastatic potential and contain a significantly higher fraction of cells possessing high electrophoretic mobility than the parent tumor. Moreover, the metastatic nodules contain a remarkably elevated fraction of the "fast moving" cells. The reported correlation between the "fast moving" cell fraction and the metastatic potential suggests that the relative content of cells having high electrophoretic mobility may determine the metastaticity of pigmented hamster melanoma.

Physician demographics and the risk of medical malpractice.

PURPOSE: This study was undertaken to clarify which, if any, physician demographic characteristics are associated with an increased rate of medical malpractice claims. METHODS: We analyzed the malpractice experience of 9,250 physicians insured for at least 2 years from 1977 to 1987 in the state of New Jersey. After adjusting for years at risk, physician claims per year was categorized into low, medium, and high. RESULTS: Male physicians were three times as likely to be in the high-claims group as female physicians, even after adjusting for other demographic variables (relative risk, 3.1; 99% confidence interval, 2.2 to 4.4). Specialty was strongly associated with claims rate, with neurosurgery, orthopedics, and obstetrics/gynecology having 7 to 12 times the number of claims per year as psychiatry, the specialty with the fewest claims. The rate of claims varied with age (p < 0.001) and peaked at approximately age 40. No association was evident between claims rate and a physician's site of training or type of degree. CONCLUSION: Male physicians are three times as likely to be in a high-claims category as female physicians. We suspect that the most likely explanation for this finding is that women interact more effectively with patients. Understanding the reasons for the variation in claim rates between physicians may lead to the development of methods to reduce the overall rate of malpractice claims.

The influence of standard of care and severity of injury on the resolution of medical malpractice claims.

OBJECTIVE: To explore how frequently physicians lose medical malpractice cases despite providing standard care and to assess whether severity of patient injury influences the frequency of plaintiff payment. DESIGN: Retrospective cohort study. SETTING: Physicians from the state of New Jersey insured by one insurance company from 1977 to 1992. PARTICIPANTS: A total of 12,829 physicians involved in 8231 closed malpractice cases. MEASUREMENTS: Physician care and claim severity were prospectively determined by the insurance company using a standard process. RESULTS: Physician care was considered defensible in 62% of the cases and indefensible in 25% of the cases, in almost half of which the physician admitted error. In the remaining 13% of cases, it was unclear whether physician care was defensible. The plaintiff received a payment in 43% of all cases. Payment was made 21% of the time if physician care was considered defensible, 91% if considered indefensible, and 59% if considered unclear. The severity of the injury was classified as low, medium, or high in 28%, 47%, and 25% of the cases, respectively. Severity of injury had a small but significant association (P < 0.001) with the frequency of plaintiff payment (low severity, 39%; medium severity, 43%; and high severity, 47%). The severity of injury was not associated with the payment rate in cases resolved by a jury (low severity, 23%; medium severity, 25%; and high severity, 23%). CONCLUSIONS: In malpractice cases, physicians provide care that is usually defensible. The defensibility of the case and not the severity of patient injury predominantly influences whether any payment is made. Even in cases that require a jury verdict, the severity of patient injury has little effect on whether any payment is made. Our findings suggest that unjustified payments are probably uncommon.