bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth inhibition of mammalian cells by eosinophil cationic protein
Authors: Maeda Takashi , Kitazoe Midori , Tada Hiroko , de Llorens Rafael , Salomon David S. , Ueda Masakazu , Yamada Hidenori , Seno Masaharu
Published: March 2003

Eosinophil cationic protein (ECP), one of the major components of basic granules of eosinophils, is cytotoxic to tracheal epithelium. However, the extent of this effect on other cell types has not been evaluated in vitro. In this study, we evaluated the effect of ECP on 13 mammalian cell lines. ECP inhibited the growth of several cell lines including those derived from carcinoma and leukemia in a dose‐dependent manner. The IC50 values on A431 cells, MDA‐MB‐453 cells, HL‐60 cells and K562 cells were␣estimated to be ≈ 1–5 µm. ECP significantly suppressed the size of colonies of A431 cells, and decreased K562 cells in G1/G0 phase. However, there was little evidence that ECP killed cells in either cell line. These effects of ECP were not enhanced by extending its N‐terminus. Rhodamine B isothiocyanate‐labeled ECP started to bind to A431 cells after 0.5 h and accumulated for up to 24 h, indicating that specific affinity for the cell surface may be important. The affinity of ECP for heparin was assessed and found to be reduced when tryptophan residues, one of which is located at a position in the catalytic subsite of ribonuclease in ECP, were modified. The growth‐inhibitory effect was also attenuated by this modification. These results suggest that growth inhibition by ECP is dependent on cell type and is cytostatic.
Tyrosine sulfation and N‐glycosylation of human heparin cofactor II from plasma and recombinant Chinese hamster ovary cells and their effects on heparin binding
Authors: Böhme Christoph , Nimtz Manfred , Grabenhorst Eckart , Conradt Harald S. , Strathmann Annemarie , Ragg Hermann
Published: March 2003

The structure of post‐translational modifications of human heparin cofactor II isolated from human serum and from recombinant Chinese hamster ovary cells and their effects on heparin binding have been characterized. Oligosaccharide chains were found attached to all three potential N‐glycosylation sites in both protein preparations. The carbohydrate structures of heparin cofactor II circulating in blood are complex‐type diantennary and triantennary chains in a ratio of 6 : 1 with the galactose being > 90% sialylated with α2→6 linked N‐acetylneuraminic acid. About 50% of the triantennary structures contain one sLex motif. Proximal α1→6 fucosylation of oligosacharides from Chinese hamster ovary cell‐derived HCII was detected in > 90% of the diantennary and triantennary glycans, the latter being slightly less sialylated with exclusively α2→3‐linked N‐acetylneuraminic acid units. Applying the ESI‐MS/ MS‐MS technique, we demonstrate that the tryptic peptides comprising tyrosine residues in positions 60 and 73 were almost completely sulfated irrespective of the protein's origin. Treatment of transfected Chinese hamster ovary cells with chlorate or tunicamycin resulted in the production of heparin cofactor II molecules that eluted with higher ionic strength from heparin–Sepharose, indicating that tyrosine sulfation and N‐linked glycans may affect the inhibitor's interaction with glycosaminoglycans.
A model for recognition of polychlorinated dibenzo‐p‐dioxins by the aryl hydrocarbon receptor
Authors: Procopio M. , Lahm A. , Tramontano A. , Bonati L. , Pitea D.
Published: March 2003

Ligand binding by the aryl hydrocarbon receptor (AhR), a member of the bHLH‐PAS family of transcriptional regulatory proteins, has been mapped to a region within the second ‘PAS’ domain, a conserved sequence motif first discovered in the Per‐ARNT‐Sim family of proteins. In addition to the bacterial photoactive yellow protein (PYP), which had been proposed as a structural prototype for the three dimensional fold of PAS domains, two crystal structures of the PAS domain have recently been determined: the human potassium channel HERG and the heme binding domain of the bacterial O2 sensing FixL protein. The three structures reveal a highly conserved structural framework in evolutionary rather distant PAS domains, provide a more general view of how these domains can recognize their ligands and suggest a structure–function relationship that we exploited to build a three‐dimensional model of the ligand binding domain (LBD) of the mouse aryl hydrocarbon receptor (mAhR). The model allowed us to putatively identify the residues responsible for the recognition of polychlorinated dibenzo‐p‐dioxins (PCDDs) by AhR receptors and to formulate an hypothesis on the signal transduction mechanism.
Cold adaptation of xylose isomerase from Thermus thermophilus through random PCR mutagenesis
Authors: Lönn Anna , Gárdonyi Márk , van Zyl Willem , Hahn‐Hägerdal Bärbel , Otero Ricardo Cordero
Published: March 2003

Random PCR mutagenesis was applied to the Thermus thermophilus xylA gene encoding xylose isomerase. Three cold‐adapted mutants were isolated with the following amino‐acid substitutions: E372G, V379A (M‐1021), E372G, F163L (M‐1024) and E372G (M‐1026). The wild‐type and mutated xylA genes were cloned and expressed in Escherichia coli HB101 using the vector pGEM®‐T Easy, and their physicochemical and catalytic properties were determined. The optimum pH for xylose isomerization activity for the mutants was ≈ 7.0, which is similar to the wild‐type enzyme. Compared with the wild‐type, the mutants were active over a broader pH range. The mutants exhibited up to nine times higher catalytic rate constants (kcat) for d‐xylose compared with the wild‐type enzyme at 60 °C, but they did not show any increase in catalytic efficiency (kcat/Km). For d‐glucose, both the kcat and the kcat/Km values for the mutants were increased compared with the wild‐type enzyme. Furthermore, the mutant enzymes exhibited up to 255 times higher inhibition constants (Ki) for xylitol than the wild‐type, indicating that they are less inhibited by xylitol. The thermal stability of the mutated enzymes was poorer than that of the wild‐type enzyme. The results are discussed in terms of increased molecular flexibility of the mutant enzymes at low temperatures.
Agmatine oxidation by copper amine oxidase
Authors: Ascenzi Paolo , Fasano Mauro , Marino Maria , Venturini Giorgio , Federico Rodolfo
Published: March 2003

The product of agmatine oxidation catalyzed by Pisum sativum L. copper amine oxidase has been identified by means of one‐ and two‐dimensional 1H‐NMR spectroscopy to be N‐amidino‐2‐hydroxypyrrolidine. This compound inhibits competitively rat nitric oxide synthase type I and type II (NOS‐I and NOS‐II, respectively) and bovine trypsin (trypsin) activity, values of Ki being (1.1 ± 0.1) × 10−5 m (at pH 7.5 and 37.0 °C), (2.1 ± 0.1) × 10−5 m (at pH 7.5 and 37.0 °C), and (8.9 ± 0.4) × 10−5 m (at pH 6.8 and 21.0 °C), respectively. Remarkably, the affinity of N‐amidino‐ 2‐hydroxypyrrolidine for NOS‐I, NOS‐II and trypsin is significantly higher than that observed for agmatine and clonidine binding. Furthermore, N‐amidino‐2‐hydroxypyrrolidine and agmatine are more efficient than clonidine in displacing [3H]clonidine (= 1.0 × 10−8 m) from specific binding sites in heart rat membranes, values of IC50 being (1.3 ± 0.4) × 10−9 m and (2.2 ± 0.4) × 10−8 m, respectively (at pH 7.4 and 37.0 °C).
Unfolding and refolding studies of frutalin, a tetrameric d‐galactose binding lectin
Authors: Campana Patricia T. , Moraes Derminda I. , Monteiro‐Moreira Ana C. O. , Beltramini Leila M.
Published: March 2003

Protein refolding is currently a fundamental problem in biophysics and molecular biology. We have studied the refolding process of frutalin, a tetrameric lectin that presents structural homology with jacalin but shows a more marked biological activity. The initial state in our refolding puzzle was that proteins were unfolded after thermal denaturation or denaturation induced by guanidine hydrochloride, and under both conditions, frutalin was refolded. The denaturation curves, measured by fluorescence emission, gave values␣of conformational stability of 17.12 kJ·mol−1 and 12.34 kJ·mol−1, in the presence and absence of d‐galactose, respectively. Native, unfolded, refolded frutalin and a distinct molecular form denoted misfolded, were separated by size‐exclusion chromatography (SEC) on Superdex 75. The native and unfolded samples together with the fractions separated by SEC were also analyzed for heamagglutination activity by CD and fluorescence spectroscopy. The secondary structure content of refolded frutalin estimated from the CD spectra was found to be close to that of the native molecule. All the results obtained confirmed the successful refolding of the protein and suggested a nucleation‐condensation mechanism, whereby the sugar‐binding site acts as a nucleus to initiate the refolding process. The refolded monomers, after adopting their native three‐dimensional structures, spontaneously assemble to form tetramers.
Mucosal tolerance as therapy of type I allergy: intranasal application of recombinant Bet v 1, the major birch pollen allergen, leads to the suppression of allergic immune responses and airway inflammation in sensitized mice
Authors: Winkler B. , Baier K. , Wagner S. , Repa A. , Eichler H.‐G. , Scheiner O. , Kraft D. , Wiedermann U.
Published: March 2003

Background Several studies have demonstrated that mucosal administration of soluble antigens can prevent the onset or reduce the severity of certain autoimmune diseases or allergies. Few studies exist showing the efficacy of mucosal tolerance for therapy of such diseases.

Objective The aim of the present study was to modulate an allergic immune response by intranasal antigen administration in an already sensitized organism.

Methods A murine model of allergic asthma to birch pollen (BP) and its major allergen Bet v 1 was utilized. Sensitized mice were intranasally treated with recombinant (r)Bet v 1 in different concentrations and at different intervals. On the day the mice were killed, blood and bronchoalveolar lavage fluids were taken and immediate type I skin tests were performed. T cell proliferation and cytokine production (interleukin (IL)‐5, interferon (IFN)‐γ) were measured in spleen and lung cell cultures.

Results Mucosal treatment with rBet v 1 (3 × 50 µg in 4 day intervals) led to a reduction of type I skin reactions, suppressed immunoglobulin (Ig)G1/IgE antibody levels and markedly decreased IL‐5 and IFN‐γ production in vitro in spleen and lung cell cultures. Moreover, lung inflammation (i.e. eosinophilia and IL‐5 levels in bronchoalveolar lavage fluids) was significantly suppressed by the treatment.

Conclusion Our results demonstrate that intranasal treatment with rBet v 1 reduced systemic allergic immune responses as well as airway inflammation in BP‐sensitized mice. We therefore suggest that mucosal tolerance induction with recombinant allergens could be a promising concept for the therapy of allergic diseases.
Reciprocal patterns of allergen‐induced GATA‐3 expression in peripheral blood mononuclear cells from atopics vs. non‐atopics
Authors: Macaubas C. , Lee P. T. , Smallacombe T. B. , Holt B. J. , Wee C. , Sly P. D. , Holt P. G.
Published: March 2003

Background T helper (Th)2 cytokines are considered to play a central role in the induction and expression of allergic disease. However, the relative importance of individual cytokines is unclear, and overall disease pathogenesis appears to involve the coordinate activities of a range of Th2 cytokines acting in sequence or in parallel. The present study examines an alternative approach to the study of cytokine gene function in atopy, focusing instead upon T cell transcription factors (TFs) which play a role in the regulation of multiple cytokine genes.

Objective To investigate the allergen‐induced expression of the TF GATA‐3 and c‐Maf in peripheral blood mononuclear cells (PBMCs) and in cytokine‐driven Th polarization.

Methods PBMC from house dust mite (HDM)‐atopic and non‐atopics were stimulated in vitro with allergen or anti‐CD3/IL‐2. TF expression was analysed by semiquantitative RT‐PCR and major findings were validated by real‐time PCR. Cell separations were performed to analyse the contribution of CD45RO+ cells. CD4+ cord blood cells were Th1 or Th2 polarized in vitro by exogenous cytokines and TF expression analysed by Northern blot and real‐time PCR.

Results We demonstrate for the first time that during differentiation of CD4+ CD45RA+ naïve human T cells towards Th2 commitment, and during allergen‐specific reactivation of peripheral CD4+ CD45RO+ Th2 memory cells in established atopics, expression of the Th2‐associated TF GATA‐3 is rapidly up‐regulated, whereas T cells from non‐atopics display equally rapid GATA‐3 down‐regulation under identical conditions of allergen stimulation.

Conclusion These findings identify Th2‐associated TFs as key determinants of the atopic phenotype, suggesting their unique potential as therapeutic targets for disease control.
Spatial and temporal habitat use of kob antelopes (Kobus kob kob, Erxleben 1777) in the Comoé National Park, Ivory Coast as revealed by radio tracking
Authors: Fischer Frauke , Linsenmair K. Eduard
Published: March 2003

Spatial and temporal habitat use of kob antelopes (Kobus kob kob) have been investigated in the Comoé National Park (Ivory Coast, West Africa) by use of radio telemetry. A total of 23 kob were equipped with radio collars and radio tracked for up to 15 months. Home ranges of males were smaller and those of females larger than expected from theoretical models. Adult males used smaller areas than adult females and did not show seasonal home range shifts. Daily distances travelled did not differ between sexes. Kob walked less during the night than by day and covered shorter distances in the wet season. Whereas an increase in home range overlap between females resulted in higher rates of association among individuals, association of adults of mixed sexes was not correlated with the degree of home range overlap. Territorial behaviour of males and predator avoidance by females are suggested to explain the sex‐specific differences in home range size of adults and the deviation from the predicted sizes. Predator avoidance is presumed as the main reason for the reduced walking distances at night as well as in the wet season. Reproductive behaviour and feeding ecology are assumed to determine the degree of association of conspecifics.
Takayasu's arteritis associated with various neurological disorders and uveitis
Authors: Bohgaki Miyuki , Mukai Masaya , Notoya Atsushi , Kohno Michifumi , Tashiro Jun
Published: March 2003

Introduction: This report describes a 51‐year‐old woman who presented with aseptic meningitis, polyneuropathy and uveitis associated with Takayasu's arteritis (TA).

Clinical picture: The patient presented with high‐grade fever, vertigo, deafness and photopsia. Although systemic vasculitis involving small arteries was suspected from her symptoms and signs, aortitis and aortic arch vessel vasculitis were found by computed tomography. We diagnosed her as having TA.

Treatment: Oral prednisolone therapy was administered to the patient.

Outcome: After treatment, the patient's symptoms and the thickening of her vessel walls reduced.

Conclusions: Although these symptoms associated with TA have been reported only rarely, it is suspected that they are associated with the same immunological pathogenesis as arteritis.
Intra‐articular hyaluronan in osteoarthritis: The clinical perspective
Authors: March L.
Published: March 2003

A review of the efficacy of intra‐articular hyaluronan products for patients with osteoarthritis (OA) of the knee will be presented. A full Cochrane systematic review of these products is pending (see Cochrane Library, Bellamy et al. Protocol).

The majority of published studies show advantages for hyaluronan and hylans over placebo for symptom modification including reduction in walking pain and improvement in physical function. The proportion of patients benefiting 6 months after their course of injections varies between published studies from 58 to 91%. Some of this variability may be accounted for by differences in baseline severity of OA as open‐labeled post‐marketing surveys have found that both the proportion of patients responding and the duration of response decreases with increasing radiological grades of OA. Patients with Grade IV OA changes were uniformly excluded from the controlled trials. Local audits suggest that less than 50% of patients are getting significant improvement from baseline. The reported rate of reactions following the injection is also variable ranging from less than 2% to more than 20% per patient. Reactions appear to be more frequent in people having a second course of injections.

Despite the variability in response, the consistent positive trend has led all major international published guidelines for OA management to recommend a trial of intra‐articular hyaluronan for patients whose knee OA is not responding to adequate analgesic therapy and maximal non‐pharmacological measures.

Whether hyaluronan also has structure modifying properties remains to be seen. One small arthroscopic study, reviewing histology before and after the injection course, found significant changes in articular cartilage parameters compared with intra‐articular corticosteroids. Another recent study, presented in abstract form, found a significant difference in joint space narrowing on standardised X‐rays between OA knee patients who had had 3 courses of hyaluronan (each of 3 injections) over a 12 month period and patients receiving placebo saline injections.

Intra‐articular hyaluronan appears to have a role in symptom relief for some patients with OA of the knee. Those with more advanced radiological damage are less likely to get a response but may still gain some benefit. Patients need to be made aware of possible local reactions which may be more frequent in the setting of coexistent crystal deposition. Preliminary work suggests that intra‐articular HA has potential for structure modification but further research is required.
Skeletal growth factors
Authors: Findlay D.
Published: March 2003

Skeletal growth factors participate in the formation of the bones and joints during development, as well as bone modelling during growth and bone remodeling in maturity. Bone morphogenetic proteins and their antagonists collaborate during skeletal morphogenesis. These and other growth factors also regulate the differentiation of mesenchymal stem cells into mature osteoblasts, and control the production of bone matrix during bone formation. They also regulate, in complex ways, the turnover of bone initiated by osteoclastic resorption of bone. Factors such as TGFβ, sequestered in the bone matrix, are released during bone resorption and are likely to be important in promoting the synthesis of new replacement bone. An understanding of the biology of agents that are anabolic in bone is enabling pharmaceutical approaches to providing better quality bone in osteoporosis and osteopenia, as well as the repair and regeneration of bone. Particular examples are the increased bone mass that can be achieved by intermittent injection of parathyroid hormone, and the enhanced repair of fracture and regeneration of bone defects that administration of BMP2 or BMP7 enables. Thus, newly available anabolic agents are enabling exciting new treatment paradigms for metabolic bone diseases, such as osteoporosis and for orthopedic procedures such as fracture repair.
Mechanisms of bone re‐modeling, resorption and repair: Therapeutic strategies for intervention
Authors: Dunstan C. R.
Published: March 2003

The skeleton is a dynamic structure contributing vitally to the body’s needs for structural support and mineral homeostasis. Bones are able to develop to appropriate size and shape, be renewed every 7–10 years, respond to changes in mechanical stress, repair and reshape after fracture, and support calcium homeostasis. The processes of bone modeling, remodeling and repair require the concerted actions of osteoclasts and osteoblasts. The activity of these cells is normally tightly regulated at the local level to initiate and direct these processes so as to maintain shape, strength and architecture of the skeleton. Systemic and local stimuli provide an integrated signal to bone cells to determine the initiation rate and duration of remodeling activity.

In disease, the regulation of bone resorption and formation can break down giving rise to systemic or local bone loss that can impair structural integrity and/or mineral homeostasis. Disease processes overwhelm local structural signals to induce excessive bone resorption, inhibit bone formation, or induce loss of bone architecture. Therapeutic strategies that restore or enhance normal local responsiveness to physiologic signals are those most likely to induce repair that is structurally sound. Thus understanding of the mechanisms of local regulation of osteoclast and osteoblast function is vital to the development of effective therapeutics.

The recent discovery of the importance of RANK signaling, as modulated by RANK ligand and osteoprotegerin (OPG), in regulating bone resorption, serves as an example of convergence of multiple systemic signals to a single signaling pathway active in the local bone environment. Inhibition of RANK signaling through treatment with recombinant OPG provides potent inhibition of bone resorption in multiple pathologic indications.

Discovery of similar pathways regulating the activity of osteoblasts at the local level could give rise to additional therapeutic modalities to improve bone structure. Different strategies may be required to thicken current bone elements, rebuild trabecular structure, bridge large defects, and then to maintain these improvements.
The genetics of osteoporosis and the search for osteoporosis genes
Authors: Sambrook P.
Published: March 2003

Osteoporosis represents a major or developing public health problem in most countries around the world. Because fracture, the clinical manifestation of the disease, is a time dependent event, bone mineral density (BMD) is most frequently used as a surrogate phenotype. Each standard deviation decrease in BMD is associated with an approximate twofold increase in fracture risk, which is similar to the magnitude of association between hypertension and cardiovascular disease. Thus, identifying factors that are involved in the determination of BMD is important in osteoporosis research.

One of the remarkable features of BMD is that it is normally distributed with a virtually constant variance throughout life. Although BMD shows an age dependent pattern of an initial increase with growth and subsequent decline in later life, twin and family studies have shown that at each stage of life, genetic factors account for up to 70 to 80% of the variance of BMD. However multiple genes appear responsible for determining BMD at various skeletal sites.

Two strategies have been used for identifying genes influencing BMD, namely genome‐wide scanning (a top down approach) and candidate genes (a bottom up approach). The latter has been most frequently used to date and two candidate genes have received the most attention, namely the vitamin D receptor and collagen genes. In 1994, a strong association between non‐coding polymorphisms in the vitamin D receptor gene and BMD was reported, although when genotyping errors were later accounted for, the effect was considerably weaker in magnitude. Numerous subsequent studies have reported an association between BMD and VDR genotypes ranging from a similar effect to no effect. In 1997, an association between polymorphisms in the collagen 1a1 gene and BMD was also reported. Again subsequent reports have supported the original findings but also shown no effect in some populations. Other candidate genes reported include the estrogen receptor, apolipoprotein E, TGFβ and IL‐6, all with varying strength of association and controversy. These discrepancies may be due to a variety of problems including inadequate study sample size, selection bias in the populations studies, gene environment effects, linkage dysequilibrium and genotyping errors. Determining the effects of gene–environment interactions on measured phenotypes is particularly complicated if multiple genetic loci are involved, as is likely, and the dose of ‘environmental exposure’ varies, as seems common between populations.

For these reasons it is likely that the top down approach, of genome‐wide scanning in appropriate large scale twin or affected sib pair populations, will prove most effective in identifying clinically meaningful osteoporosis genes in the future.
Environmentally induced variation in size, energy reserves and hydration of hatchling Painted Turtles, Chrysemys picta
Authors: Packard G. C. , Packard M. J.
Published: March 2003

The contents of newly constructed nests of Painted Turtles, Chrysemys picta (Schneider 1783), were manipulated by reciprocal transplant so that each of several nests received a complement of eggs from each of several females. The eggs were recovered from nests after 8 weeks and allowed to complete their incubation under standard conditions in the laboratory. The design of the experiment enabled us to distinguish between environmental and maternal effects on attributes of hatchlings.

Several measures of body size and energy reserve varied among turtles hatching from eggs that incubated in different nests, and certain of these measures varied also among turtles hatching from eggs that incubated in different layers within nests. The effects of nest and layer were substantial. For example, fat‐free carcasses of hatchlings from one nest weighed 17% more than those of neonates from a second nest, but fat‐free yolks from the former weighed only 53% as much as yolks from the latter.

Stepwise linear regression indicated that the size of hatchlings and the hydration and fat content of their carcasses were positively correlated with the net change in mass of eggs (which is an index to net water‐exchange) while they incubated in the field. In contrast, both the fat and fat‐free components of unused yolk were negatively correlated with change in mass of eggs. Although the statistical procedure is only correlative, the findings accord well with results of laboratory studies documenting a relationship between uptake of water by eggs, metabolism and growth by embryos, and size and condition of hatchlings.

Variation among hatchlings representative of different nests accounted for 24% of the statistical variance in mass of dry, fat‐free carcasses; 29% of the variance in mass of dry, fat‐free yolks; 19% of the variance in mass of storage fat in yolks; and 11% of the variance in mass of storage fat in carcasses. Additional variation was detected between the upper and lower layers of nests. Such environmentally induced variation probably affects survival of neonatal animals in the field.
A standardized protocol for the determination of specific leaf area and leaf dry matter content
Authors: Garnier E. , Shipley B. , Roumet C. , Laurent G.
Published: March 2003

The impact of sample preparation, rehydration procedure and time of collection on the determination of specific leaf area (SLA, the ratio of leaf area to leaf dry mass) and leaf dry matter content (LDMC, the ratio of leaf dry mass to fresh mass) of mature leaves was studied in three wild species growing in the field, chosen for their contrasting SLA and LDMC.

 Complete rehydration was achieved 6 h after samples were placed into water, but neither of the procedures tested – preparation of samples before rehydration or temperature applied during rehydration – had a significant effect on the final values of SLA or LDMC.

 As expected, water‐saturated leaves had a lower LDMC than non‐rehydrated leaves; more surprisingly, their SLA was also higher. The impact of rehydration on SLA was especially important when the SLA of the species was high.

 There was no significant effect of time of sampling on either trait in any species over the time period covered (09·00–16·30 h).

 These results suggest that SLA and LDMC obtained on water‐saturated leaves (SLASAT and LDMCSAT) can be used for species comparisons. We propose a standardized protocol for the measurement of these traits. This would allow for better consistency in data collection, a prerequisite for the constitution of large databases of functional traits.
Long‐term effects of lanreotide SR and octreotide LAR® on tumour shrinkage and GH hypersecretion in patients with previously untreated acromegaly
Authors: Amato Giovanni , Mazziotti Gherardo , Rotondi Mario , Iorio Sergio , Doga Mauro , Sorvillo Francesca , Manganella Giovanni , Di Salle Francesco , Giustina Andrea , Carella Carlo
Published: March 2003

background and objective The therapeutic efficacy of lanreotide SR and octreotide LAR® has been studied widely in patients treated previously with neurosurgery and/or radiotherapy. These therapies limit the evaluation of the long‐term effects of somatostatin analogues on tumour shrinkage. Neurosurgical and radiotherapy treatments cause irreversible anatomical changes in pituitary morphology, which can make accurate evaluation of tumour shrinkage difficult. The aim of this study was to investigate the therapeutic efficacy of lanreotide SR and octreotide LAR® in previously untreated patients with acromegaly. We aimed to investigate the long‐term effects of these drugs on tumour shrinkage and growth hormone (GH) hypersecretion without the confounding influences of previous therapy.

patients and methods Twenty‐three newly diagnosed patients with acromegaly (14 women, nine men) with active disease began the study; of these, three were lost for follow‐up, leaving a total of 20 patients to complete the study. Patients were assigned randomly to lanreotide SR (12 patients) and octreotide LAR® (eight patients), and the randomization stratified patients to assure a balance between the groups with respect to baseline tumour dimension, age and sex. Tumour volume was evaluated by magnetic resonance imaging of the sella, and calculated with the rotating ellipsoid formula. A morphological and biochemical evaluation was performed at baseline, 12 and 24 months after beginning lanreotide SR and octreotide LAR® treatment. A reduction of tumour volume of at least 10% was considered significant.

results Biochemical control increased progressively throughout the study in patients with microadenomas more than in patients with macroadenomas (70%vs. 10%; P < 0·05) and without a difference between lanreotide SR and octreotide LAR® (41·0%vs. 37·5%; P not significant). After 12 months of treatment, mean tumour shrinkage was 28·3 ± 18·0%. A greater reduction was observed in macro‐ vs. microadenomas (40·5 ± 17·0%vs. 16·1 ± 8·0%, respectively; P < 0·05). No statistical difference in the tumour shrinking effects of lanreotide SR vs. octreotide LAR® was observed (26·5 ± 17·3%vs. 31·1 ± 16·1%, respectively). At the 24th month of therapy, no further overall shrinkage was observed, compared to the 12‐month evaluation (31·9 ± 17·2%vs. 28·3 ± 18·0%) at which there was no difference between lanreotide SR and octreotide LAR® (30·0 ± 17·2%vs. 34·8 ± 16·5%, respectively).

conclusions This study showed that the new long‐acting somatostatin analogues, lanreotide SR and octreotide LAR®, cause significant shrinkage of pituitary GH‐secreting adenomas in previously untreated patients with acromegaly. This effect was more marked in macroadenomas than microadenomas, and did not correlate with control of GH hypersecretion.
Severe impairment of bone mass and turnover in Cushing’s disease: comparison between childhood‐onset and adulthood‐onset disease
Authors: Di Somma Carolina , Pivonello Rosario , Loche Sandro , Faggiano Antongiulio , Marzullo Paolo , Di Sarno Antonella , Klain Michele , Salvatore Marco , Lombardi Gaetano , Colao Annamaria
Published: March 2003

background Osteoporosis is an important, frequently unrecognized consequence of hypercortisolism.

objective

 To evaluate whether the age of onset of hypercortisolism influences its effects on bone mass and turnover.

subjects  10 with childhood‐onset (co) and 18 with adulthood‐onset (ao) Cushing’s disease (CD); 28 age‐, sex‐ and body mass index (BMI)‐matched healthy subjects served as controls.

study design Open, cross‐sectional controlled.

measurements

 Bone mineral density (BMD) at lumbar spine, serum osteocalcin (OC), and urinary N‐telopeptides of type I collagen (Ntx) levels.

results  BMD at lumbar spine was significantly lower in all CD patients than in controls (Z score, −2·3 ± 0·1 vs.−0·2 ± 0·01; P < 0·001). co‐CD and ao‐CD patients had similar values of bone mass when expressed as Z score (−2·6 ± 0·4 vs.−2·1 ± 0·2; P = 0·27) or as BMD (0·728 ± 0·03 vs. 0·78 ± 0·03 g/cm2; P = 0·25). In particular, osteoporosis was observed in 16 patients (57·1%) [eight adolescents (80%) and eight adults (44·4%)] and none of the controls; osteopenia was found in two co‐CD patients (20%) and none of the healthy adolescents, 10 ao‐CD patients (55·6%) and four healthy adults (14·3%) (χ2 = 7·87, P < 0·01; χ2 = 2·99, P = 0·09, respectively). In co‐CD and ao‐CD patients, serum OC levels were similar and significantly lower than in controls (P < 0·01); urinary Ntx levels were significantly higher than in controls (P < 0·001) and were significantly higher in co‐CD than in ao‐CD patients (P < 0·001). No significant correlation was found between urinary cortisol levels, serum cortisol and age and lumbar Z score values, while a significant correlation was found between Ntx levels and disease duration (r = 0·434; P = 0·021) and plasma cortisol (r = 0·440; P = 0·019).

conclusions  Cushing’s disease causes bone loss and abnormalities of bone turnover both in childhood‐onset and in adulthood‐onset patients. A strict follow‐up of bone mass and turnover is mandatory in all patients with Cushing’s disease to prevent fractures later in life and specific treatment for bone loss is strongly suggested.
Genetic and clinical characterization of sporadic cystic parathyroid tumours
Authors: Villablanca Andrea , Farnebo Filip , Teh Bin Tean , Farnebo Lars‐Ove , Höög Anders , Larsson Catharina
Published: March 2003

objective  The hyperparathyroidism–jaw tumour (HPT–JT) syndrome is one of the familial disorders characterized by primary hyperparathyroidism and has been linked to the chromosomal region of 1q32–q21. The parathyroid tumours related to this syndrome have shown loss of wild‐type alleles at this locus suggesting that inactivation of a tumour suppressor gene might be responsible for the disease. In the majority of these tumours cysts are a prominent feature. By loss of heterozygosity (LOH) studies, we investigated the region of interest in an attempt to clarify its possible role in a series of cystic sporadic parathyroid adenomas.

design and subjects  A total of 30 patients diagnosed with sporadic hyperparathyroidism were included in the study, genotyped with 17 polymorphic microsatellite markers at chromosome 1q, and additional markers from 1p and 11q13 which are commonly involved in sporadic parathyroid tumours. The cystic parathyroid tumours were characterized clinically, and immunohistochemistry against PTH was carried out to confirm the parathyroid origin of the cysts.

results  LOH was found in six of 30 tumours (20%) on 1q, six of 30 tumours (20%) on 1p and five of 30 tumours (17%) on 11q13. We found a significant correlation between allelic alterations and the clinical parameters, tumour weight and PTH. Furthermore, we found a significant difference between tumour weight and PTH in cases of cystic parathyroid tumours compared with unselected sporadic cases.

conclusions  These results suggest that cystic parathyroid tumours might represent a new subgroup among parathyroid tumours based on the genetic and clinical findings. Loss of heterozygosity at 1q further supports the presence of a tumour suppressor gene at this locus.
Continuing Medical Education in Clinical Pharmacology and Therapeutics: report of a questionnaire survey
Authors: Mucklow J. C.
Published: March 2003

Aims  To seek the views of medically qualified members of the Clinical Section of the British Pharmacological Society (BPS) on their perceived needs for Continuing Medical Education (CME); on how and by whom these needs should be addressed; and on how the outcome of any educational intervention might best be assessed.

Methods
A structured questionnaire.

Results
Of 233 recipients, 140 (60%) responded, but only 123 of these fulfilled the criteria for analysis. A large majority of respondents were clinicians, most of whom devoted at least 25% of their working week to their NHS commitment. There was widespread reliance on textbooks and journals as sources of CME, supplemented by discussions with specialist peers at national and international meetings. Many felt that fulfilling even this agenda was stretching their commitment to the limit, and their greatest need was for protected time in which to learn. There was a desire among 49% of all respondents for the BPS Clinical Section to take some responsibilty for addressing the future needs of its members, and 75% took the view that academic departments should contribute to the development and updating of materials. There was no clear agreement about what these should comprise, but around half of all respondents favoured web‐based, journal‐based or computer‐assisted educational material offering self‐assessment opportunities; and CME symposia or workshops at BPS meetings. Almost half (46%) felt that assessment of CME should be integrated with a well‐organized appraisal system and the use of portfolios. Six out of 10 respondents were already, or were about to be, regularly appraised at their place of work.

Conclusions
The questionnaire survey revealed a broad canvas of views and little evidence of consensus except for a general plea for more time in which to learn. The aim of the Clinical Section should be to facilitate and help its members to organize their learning, in a way that is consistent with national trends in Continuing Professional Development. The Clinical Section should co‐ordinate the setting up of an electronic library of appropriate published material, compiled by academic and industrial sources, that would guide members seeking up‐to‐date knowledge of Clinical Pharmacology and Therapeutics. The British Journal of Clinical Pharmacology (BJCP) should commission review articles on recent developments where no suitable published material exists. Academic departments should also be invited to identify or develop self‐assessment material that members could use to reinforce their learning, and demonstrate their knowledge to relevant professional bodies. The Clinical Section should organize Symposia and Workshops at which contentious issues in Clinical Pharmacology and Therapeutics can be discussed and resolved.
The use of sputum cell counts to evaluate asthma medications
Authors: Parameswaran Krishnan , Hargreave Frederick E.
Published: March 2003

Total and differential cell counts from hypertonic‐induced, dithiothreitol‐dispersed sputum provide reproducible measurements of airway inflammatory cell counts, which are responsive to treatment with anti‐inflammatory drugs. They have helped to understand the kinetics of inflammatory cell changes in asthma after the reduction of corticosteroids and the subsequent re‐introduction of treatment. They have identified that the presence of sputum eosinophilia in asthma, chronic cough and chronic airflow limitation is a predictor of steroid‐responsiveness and of lack of ‘asthma control’. They can be used to study the dose–response effect of inhaled corticosteroids and may be useful to establish the relative potency of different corticosteroid formulations and delivery devices. Sputum cell counts are also useful to study the potential anti‐inflammatory effects of drugs like theophylline, long‐acting β‐adrenoceptor agonists, leukotriene antagonists and newer drugs in development. They may be helpful to select add‐on therapy to corticosteroids in ‘difficult‐to‐control’ asthma.
Statins for primary prevention: at what coronary risk is safety assured?
Authors: Jackson Peter R. , Wallis Erica J. , Haq Ifti U. , Ramsay Lawrence E.
Published: March 2003

Aims  Increasingly HMG CoA reductase inhibitors (statins) are being used for primary prevention of vascular disease in patients with a raised cholesterol but at low absolute risk of coronary heart disease (CHD). This study uses clinical trial results to explore the limits of absolute safety for statin use in such patients.

Methods  The major placebo controlled statin outcome trials were identified by automated and manual literature searches. Principal results including all cause mortality in placebo and intervention groups and baseline values of standard coronary risk factors were abstracted for each trial. For the trials identified the reduction in overall mortality with statin treatment for each study was regressed against the underlying CHD risk of the population recruited into that trial using a statistically robust method.

Results  The regression line describing the relationship between mortality benefit and risk suggests that statin use could be associated with an increase in mortality of 1% in 10 years. This would be sufficiently large to negate statin's beneficial effect on CHD mortality in patients with a CHD event risk less than 13% over 10 years.

Conclusions  Absolute safety of statins has not been demonstrated for patients at low risk of CHD. Patients absolute risk of CHD should be calculated before starting statin treatment for primary prevention. Extensions of such treatment to low risk patients should await further evidence of safety.
The pharmacokinetic properties of intramuscular artesunate and rectal dihydroartemisinin in uncomplicated falciparum malaria
Authors: Ilett Kenneth F. , Batty Kevin T. , Powell Shane M. , Binh Tran Quang , Thu Le Thi Anh , Phuong Hoang Lan , Hung Nguyen Canh , Davis Timothy M. E.
Published: March 2003

Aims  To obtain pharmacokinetic data for artesunate (ARTS) and its active metabolite dihydroartemisinin (DHA) following i.m. ARTS and rectal DHA administration.

Methods  Twelve Vietnamese patients with uncomplicated falciparum malaria were randomized to receive either i.v. or i.m. ARTS (120 mg), with the alternative preparation given 8 h later in an open crossover design. A further 12 patients were given i.v. ARTS (120 mg) at 0 h and rectal DHA (160 mg) 8 h later.

Results  Following i.v. bolus, ARTS had a peak concentration of 42 µm (16 mg l−1), elimination t1/2 = 3.2 min, CL = 2.8 l h−1 kg−1 and V = 0.22 l kg−1. The Cmax for DHA was 9.7 µm (2.7 mg l−1), t1/2 = 59 min, CL = 0.64 l h−1 kg−1 and V =  0.8 l kg−1. Following i.m. ARTS, Cmax was 2.3 µm (3.7 mg l−1), the apparent t1/2 = 41 min, CL = 2.9 l h−1 kg−1 and V = 2.6 l kg−1. The relative bioavailability of DHA was 88%, Cmax was 4.1 µm (1.16 mg l−1) and t1/2 = 64 min. In the rectal DHA study, relative bioavailability of DHA was 16%.

Conclusions  For patients with uncomplicated falciparum malaria i.m. ARTS is a suitable alternative to i.v. ARTS, at equal doses. To achieve plasma DHA concentrations equivalent to parenteral administration of ARTS, rectal DHA should be given at approximately four‐fold higher milligram doses. Further studies are needed to determine whether these recommendations can be applied to patients with severe malaria.
5‐HT1B‐receptors and vascular reactivity in human isolated blood vessels: assessment of the potential craniovascular selectivity of sumatriptan
Authors: Razzaque Z. , Pickard J. D. , Ma Q.‐P. , Shaw D. , Morrison K. , Wang T. , Longmore J.
Published: March 2003

Aims  5‐HT1B‐receptor mediated vasoconstriction of cranial arteries is a potential mechanism by which 5‐HT1B/1D‐receptor agonists such as sumatriptan produce their antimigraine effects. 5‐HT1B‐receptors exist in other blood vessels which may give rise to unwanted vascular effects. Therefore we examined the distribution of 5‐HT1B‐receptor immunoreactivity (i.r.) in human blood vessels (including target and nontarget vessels) and confirmed the functionality of this receptor protein, by comparing the vasoconstrictor effects of sumatriptan and 5‐HT (the endogenous ligand) in isolated vessels.

Methods  Blood vessels (middle meningeal, pial, temporal and uterine arteries and saphenous veins) were obtained from surgical patients (with consent). Sections of the vessels were prepared for routine immunohistochemical studies using specific 5‐HT1B‐ and 5‐HT1D‐receptor antibodies. For functional studies, ring segments of the vessels were mounted in organ baths for isometric tension recording.

Results  5‐HT1B‐receptor i.r. was detected on the smooth muscle layer in middle meningeal, pial and uterine arteries and in saphenous vein and sumatriptan produced contractions in these vessels with potency values (mean pEC50) of 7.00, 7.08, 6.44 and 6.61, respectively, the magnitude of contraction was greatest in the cranial arteries with Emax values of 100.7, 60.3, 23.0 and 35.9%, respectively (expressed as a percentage of the reference agonist 45 mm KCl). 5‐HT1B‐receptor i.r. was not detected in temporal artery and sumatriptan had no effect in this artery. 5‐HT1D‐receptor i.r. was not detected in any of the vessels studied.

Conclusions  Sumatriptan can evoke vasoconstriction in antimigraine target vessels and also in nontarget vessels through an action at 5‐HT1B‐rcceptors. Sumatriptan acts preferentially to cause contraction in human cranial arteries compared with the other blood vessels we examined and this effect is likely to be shared by other drugs of this class.
Adrenomedullin (ADM) in the human forearm vascular bed: effect of neutral endopeptidase inhibition and comparison with proadrenomedullin NH2‐terminal 20 peptide (PAMP)
Authors: Wilkinson Ian B. , McEniery Carmel M. , Bongaerts Katherine H. , MacCallum Helen , Webb David J. , Cockcroft John R.
Published: March 2003

Aims  To compare the haemodynamic responses of proadrenomedullin N‐terminal 20 peptide (PAMP) and adrenomedullin (ADM) in the forearm vascular bed of healthy male volunteers, and to investigate the role of neutral endopeptidase (NEP) in the metabolism of ADM.

Methods  On two separate occasions, ADM (1–30 pmol min−1) and PAMP (100–3000 pmol min−1) were infused into the brachial artery of eight male subjects, and forearm blood flow (FBF) assessed using venous occlusion plethysmography. In a second study, eight male subjects received the same doses of ADM, co‐infused with either the NEP inhibitor thiorphan (30 nmol min−1) or the control vasoconstrictor noradrenaline (120 pmol min−1), on separate occasions. Both studies were conducted in a double‐blind, randomized manner.

Results
ADM and PAMP produced a dose‐dependent increase in FBF (P ≤ 0.002). Based on the dose producing a 50% increase in FBF, ADM was ∼60 times more potent than PAMP. Thiorphan and noradrenaline produced similar reductions in FBF of 14 ± 4% (mean ± s.e. mean) and 22 ± 6%, respectively (P = 0.4). However, the area under the dose–response curve was significantly greater during co‐infusion of ADM with thiorphan than with noradrenaline (P = 0.028), as was the maximum increase in FBF ratio (2.1 ± 1.0 vs 1.2 ± 0.2; P = 0.030).

Conclusions
ADM and PAMP both produce a local dose‐related vasodilatation in the human forearm, but PAMP is ∼60 times less potent than ADM. In addition, NEP inhibition potentiates the haemodynamic effects of ADM. These findings suggest that PAMP may not play a role in the physiological regulation of blood flow. However, in pathophysiological conditions such as hypertension and heart failure, NEP inhibition may exert a beneficial effect by increasing the biological activity of ADM.