bluuebunny/crossref_metadata_2025 huggingface dataset:
Apparent competition between two species of aphid via the fungal pathogen Erynia neoaphidis and its interaction with the aphid parasitoid Aphidius ervi
Authors: Pope T. , Croxson E. , Pell J. K. , Godfray H. C. J. , Müller C. B.
Published: March 2003

Abstract 1. Motivated by a community study on aphids and their fungal pathogens, three hypotheses were tested experimentally to investigate the influence of the fungal pathogen, Erynia neoaphidis Remaudière and Hennebert, on aphid population and community ecology.

2. Field experiments were performed in 2 years to test whether two susceptible aphid species on different host plants might interact through the shared fungal pathogen. No strong pathogen‐mediated indirect interactions (apparent competition) between populations of pea aphid Acyrthosiphon pisum Harris and nettle aphid Microlophium carnosum Buckton were detected.

3. In the first of the field experiments, pea aphids exposed to the fungus showed a weak tendency to produce more winged dispersal morphs than control populations not exposed to the fungus. In a laboratory test, however, no support was found for the hypothesis that the presence of volatiles from fungus‐infected cadavers promotes production of winged offspring.

4. The response of the pea aphid parasitoid Aphidius ervi Halliday to colonies containing hosts infected 1 and 3 days previously was assessed. Wasps initiated fewer attacks on 1‐day‐old infected colonies than on healthy colonies, with the numbers on 3‐day‐old fungus‐infected colonies intermediate.
Detection and typing of tomato yellow leaf curl viruses
Authors: Moriones E.
Published: March 2003

The denomination Tomato yellow leaf curl virus (TYLCV) comprises several viruses that cause severe damage to tomato crops in warm and temperate regions worldwide. TYLCV viruses are widespread in the Mediterranean Basin, in which two species have been reported: Tomato yellow leaf curl Sardinia virus (TYLCSV) and Tomato yellow leaf curl virus (TYLCV, previously TYLCV‐Is). The availability of methods convenient for the diagnosis of these viruses is essential. We have investigated several alternatives for reliable detection and differentiation of TYLCSV and TYLCV. Triple‐antibody sandwich enzyme‐linked immunosorbent assay (TAS‐ELISA) proved to be very useful for large‐scale diagnosis in field situations, but lacked discriminating capacity and sensitivity in the stages of infection in which low virus titre is present. The DNA‐based methods are suited to laboratory operations and plant disease clinics, where accuracy of detection and discrimination of viruses is required. Polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) was the most reliable method to discriminate between TYLCSV and TYLCV, but is not suited to high sample turnover. For large‐scale testing, tissue print hybridization assay provides a reliable and sensitive alternative to PCR.
Sanitary status of grapevines in south‐eastern and central Anatolia (Turkey)
Authors: Cigsar I. , Digiaro M. , Martelli G. P.
Published: March 2003

Surveys were carried out in commercial vineyards in the main grapevine‐growing areas of south‐eastern (Adiyaman, Diyarbakir, Merdin, Sanliurfa, Elazig) and central (Nevşehir) Anatolia (Turkey) to assess the presence and incidence of virus and virus‐like diseases. Typical fanleaf symptoms were observed in most of the surveyed areas, but they were particularly frequent in Elazig in cvs Kirmizi, Agin, Sirfoni and Kohnu. Leafroll symptoms were present in most vineyards in Adiyaman, Sanliurfa and Elazig, primarily in the red‐fruited cvs Antep Karasi, Humusi, Kohnu and Siyah Kabarcik, and in Nevşheir. Rugose wood symptoms were common in Adiyaman, where vineyards were established with grafted planting material, but not in any of the self‐rooted Cappadocian cultivars. Phytoplasma‐like symptoms were sometimes observed in Elazig and Nevşheir. Biological (sap inoculation to herbaceous plants and graft transmission to woody indicators) and serological (ELISA) assays were used for virus detection and identification. A total of 55.3% of ELISA‐tested vines (296 out of 535) were infected by one (11.4%) or more (43.9%) viruses. GVA1 was the most widespread virus (42.4%), followed by GLRaV‐1 (38.5%), GFLV (10.7%) and GFkV (7.1%). Surprisingly low (2.4%) was the infection rate by GLRaV‐3, and even lower (<1%) that of the other viruses tested, i.e. GLRaV‐2, GLRaV‐6, GVB and ArMV. GLRaV‐7 was not detected. The occurrence of vein mosaic and vein necrosis was ascertained by testing on woody indicators. A putative nepovirus was isolated from a single vine of cv. Kizlar Tahtasi, the identification and characterization of which is still under way.
Immunoreactive osteocalcin forms in conditioned media from human osteoblast culture and in sera from healthy adult control subjects and patients with bone pathologies
Authors: Diaz Diego  , Nacher  , Rapado  , Serrano  , Bosch  , Aubia  , De La Piedra
Published: March 2003

Background

The aim of this work was to study the immunoreactive forms of bone Gla protein (BGP) present in conditioned media of human osteoblast cultures (BGP released from osteoblast) and in the sera of healthy adult control subjects and patients with bone pathologies (chronic renal failure on haemodialysis, Paget's disease of bone and post‐menopausal osteoporosis).

Methods

The technical procedure used was a combination of high‐performance liquid chromatography (HPLC) and different BGP assays with several specificities to analyse BGP levels in the different HPLC fractions. Aliquots of conditioned media or sera were purified through a Sephadex G‐50m column and by HPLC (C4 reverse‐phase column) in a 25–40% acetonitrile gradient. Two‐minute fractions were collected and divided into three aliquots in order to determine osteocalcin content using three different assays: (a) ELSA–OST–NAT IRMA, which only detects intact osteocalcin; (b) ELSA–OSTEO IRMA, which detects intact osteocalcin and N‐terminal fragments; and (c) OSCA Test RIA, which detects intact osteocalcin, C‐terminal and other fragments.

Results

We found different immunoreactive forms of osteocalcin in the culture medium of human osteoblasts and in sera from control subjects and patients for the bone pathologies studied. We did not find great qualitative differences between the immunoreactive osteocalcin profile found in the culture medium from human osteoblasts and the sera from healthy control subjects. However, the different bone pathologies show different characteristic patterns of immunoreactive forms of osteocalcin.

Conclusions

An interesting finding has been the detection, both in sera and in osteoblast culture media, of several immunoreactive forms of intact osteocalcin that eluted from HPLC at different acetonitrile percentages, and therefore correspond to different molecular forms.
Pharmacological intervention: the antidiabetic approach
Authors: Melander
Published: March 2003

Impaired glucose tolerance (IGT) progresses to non‐insulin‐dependent diabetes mellitus (NIDDM) in many but not all IGT subjects. It remains unsettled whether long‐term antidiabetic (i.e. antihyperglycaemic) pharmacotherapy delays the development of NIDDM, and whether such treatment influences macrovascular morbidity and mortality. This report summarizes the results from long‐term (> 4 years) antihyperglycaemic interventions addressing these issues. In an American study, tolbutamide (0·5 g 2–3 times daily) promoted a 4‐year improvement of glucose tolerance in young, non‐obese, mildly diabetic asymptomatic subjects who apparently comprised a mixture of IGT and NIDDM. In a Swedish 5‐year study on 178 survivors of myocardial infarction, of whom 79 had intravenous IGT, tolbutamide treatment was associated with improved glucose tolerance, reduced triglyceride levels, and improved 18‐month survival. A British 5‐year study on a subgroup of about 200 middle‐aged men from the Whitehall cohort indicated that phenformin (50 mg once daily) did not influence the deterioration of glucose levels. In a 10‐year British study, 241 middle‐aged men and women were 4‐square randomized to control, weight reduction, placebo and tolbutamide (0·5 g twice daily). A non‐lasting reduction of arterial disease was recorded in those on tolbutamide. No reduction of NIDDM development was seen. In a Swedish 10‐year study on middle‐aged men with IGT, follow‐up comprised 59 controls, 98 on diet advice with or without placebo, and 23 on tolbutamide (0·5 g three times daily) added to diet advice. A total of 29% developed NIDDM among controls and 13% in the diet group. In contrast, no subject maintaining tolbutamide treatment developed NIDDM. Moreover, the tolbutamide‐treated subjects had reduced blood pressure, triglyceride and cholesterol levels, as well as fewer macrovascular complications. Recently, a lower mortality rate at 22 years after the start of tolbutamide treatment has been recorded. To summarize, treatment with insulin‐releasing drugs might help to reduce the development of NIDDM and macrovascular disease in IGT subjects. However, further studies are needed to verify or refute this notion.
Plasma homocysteine concentration related to diet, endothelial function and mononuclear cell gene expression among male hyperlipidaemic smokers
Authors: Brude I. R. , Finstad H. S. , Seljeflot I. , Drevon C. A. , Solvoll K. , Sandstad B. , Hjermann I. , Arnesen H. , Nenseter M. S.
Published: March 2003

Background

Elevated plasma concentration of homocysteine is an independent risk factor for development of cardiovascular diseases.

Materials and methods

We evaluated potential links between homocysteine and atherothrombogenesis by relating the plasma concentration of homocysteine to (i) dietary antioxidants and omega‐3 fatty acids (and determined influence of intervention with antioxidants or omega‐3 fatty acids); (ii) markers of endothelial cell function; and (iii) peripheral blood mononuclear cell mRNA levels.

Results

We observed an inverse relationship between the plasma homocysteine concentration and dietary intake of vegetables, vitamin C and β‐carotene and between homocysteine and the serum concentration of folate, vitamin B12 and omega‐3 fatty acids. Intervention with antioxidants or omega‐3 fatty acids did not affect plasma homocysteine concentration. The plasma levels of cysteinylglycine and vitamin B12 correlated positively with circulating E‐selectin and VCAM‐1, respectively, whereas folate in serum and blood correlated negatively with P‐selectin. A negative correlation was found between the concentrations of homocysteine and von Willebrand factor. Negative and positive correlations were found between plasma homocysteine and the mononuclear cell mRNA levels of peroxisome proliferator activated receptor δ (PPARδ) and c‐myc respectively. A negative correlation was also found between plasma homocysteine and mononuclear cell mRNA levels of the proteoglycan serglycin. Homocysteine was not correlated with serum activity of glutathione peroxidase or with the mRNA level of glutathione peroxidase in mononuclear cells.

Conclusion

The plasma homocysteine level was negatively correlated with dietary intake of vegetables, including vitamins C and E, and serum omega‐3 fatty acids, whereas supplementation with antioxidants or omega‐3 fatty acids did not affect plasma homocysteine concentration. Homocysteine was not associated with circulating adhesion molecules or increased procoagulant activity, but homocysteine may alter mononuclear cell gene expression. Cysteine showed no significant correlation with these parameters.
Atrial natriuretic peptide increases albuminuria in type 1 diabetic patients: evidence for blockade of tubular protein reabsorption.
Authors: Jacobs E. M. G. , Vervoort G. , Branten A. J. W. , Klasen I. , Smits P. , Wetzels J. F. M.
Published: March 2003

Background

It has been suggested that atrial natriuretic peptide (ANP) contributes to the glomerular hyperfiltration of diabetes mellitus. Infusion of ANP increases the urinary excretion of albumin in patients with type 1 diabetes mellitus (IDDM). Although the increased albuminuria is attributed to a rise in glomerular pressure, alterations in tubular protein handling might be involved.

Patients and methods

We have studied the effects of ANP in nine microalbuminuric IDDM patients. After obtaining baseline parameters, ANP was infused over a 1‐h period (bolus 0.05 μg kg−1, infusion rate 0.01 μg kg−1 min−1). Renal haemodynamics, sodium and water clearance and tubular protein handling were studied.

Results

The glomerular filtration rate (GFR) increased from 116.4 ± 8.9 to 128.3 ± 8.8 mL min−1 1.73 m−2, whereas the effective renal plasma flow (ERPF) decreased from 534.3 ± 44.3 to 484.9 ± 33.3 mL min−1 1.73m−2 (P < 0.05). As a result, the filtration fraction was significantly higher during infusion of ANP. ANP attenuated proximal tubular sodium reabsorption. Urinary albumin excretion rose from 87.57 ± 21.03 to 291.40 ± 67.86 μg min−1 (P < 0.01). Changes in the urinary excretion of β2‐microglobulin and free κ‐light chains were more marked, the excretion of β2‐microglobulin increasing from 0.28 ± 0.21 to 51.87 ± 10.51 μg min−1 (P < 0.01), and of free κ‐light chains from 4.73 ± 1.74 to 46.14 ± 6.19 μg min−1 (P < 0.01).

Conclusions

The observed rise in albuminuria during infusion of ANP does not simply reflect a change in glomerular pressure, but might at least partly result from an attenuation of tubular protein reabsorption.
Cardiomyocyte apoptosis and progression of heart failure to transplantation
Authors: Saraste  , Pulkki  , Kallajoki  , Heikkilä  , Laine  , Mattila  , Nieminen  , Parvinen  , Voipio‐Pulkki
Published: March 2003

Background

Cardiomyocyte apoptosis has been found in congestive heart failure, but its clinical significance has been difficult to study. We compared the occurrence of cardiomyocyte apoptosis in explanted hearts with the progression of severe heart failure until the need for transplantation.

Design

Using the TUNEL assay, apoptotic cardiomyocytes were quantified in explanted failing hearts from patients with either idiopathic dilated cardiomyopathy (n = 21) or ischaemic heart disease (n = 14). The percentage was compared with the clinical severity and progression of end‐stage heart failure. Samples obtained at autopsy and during open heart surgery served as controls.

Results

The number of apoptotic cardiomyocytes was significantly increased in failing hearts regardless of aetiology (medians 0.075% in ischaemic heart disease and 0.119% in dilated cardiomyopathy) compared with control myocardium. In patients with dilated cardiomyopathy, apoptotic cardiomyocytes were more numerous in subjects with a rapidly deteriorating clinical course (0.192%, n = 10) than in patients with intermediate (0.093%, n = 6, P = 0.03) or slow (0.026%, n = 5, P = 0.003) progression. No such association was observed in patients with ischaemic heart disease, in whom we found significantly increased cardiomyocyte apoptosis adjacent to scars of previous infarctions (0.576%) in contrast to the diffuse distribution seen in dilated cardiomyopathy. Expression of Bcl‐2, an antiapoptotic protein, was increased in all failing hearts by immunohistochemistry.

Conclusion

Cardiomyocyte apoptosis is a consistent feature of end‐stage heart failure in man and appears to be quantitatively related to the clinical severity of deterioration in dilated cardiomyopathy. Increased expression of Bcl‐2 in cardiomyocytes indicates activation of an antiapoptotic response. These observations suggest that cardiomyocyte apoptosis is a clinically relevant and potentially modifiable pathophysiological phenomenon in severe heart failure.
Effect of cholestyramine on bile acid pattern and synthesis during administration of ursodeoxycholic acid in man
Authors: Rust  , Sauter  , Oswald  , Büttner  , Kullak‐Ublick  , Paumgartner  , Beuers
Published: March 2003

Background

Cholestyramine is the first‐line treatment for cholestasis‐induced pruritus and is prescribed along with ursodeoxycholic acid (UDCA) in patients with cholestatic liver diseases. Impairment of the intestinal absorption of endogenous hydrophobic bile acids by cholestyramine is well known. It is unclear, however, whether cholestyramine also impairs the absorption of the hydrophilic bile acid, UDCA, in man.

Aims

To study serum levels of UDCA and endogenous bile acids as well as endogenous bile acid synthesis during simultaneous or separate administration of UDCA and cholestyramine in vivo; and absorption of UDCA both in the presence and absence of its hydrophobic epimer, chenodeoxycholic acid (CDCA), by cholestyramine in vitro.

Patients and methods

Five healthy subjects received UDCA (12.5 ± 0.5 mg kg−1 daily) as a single dose for periods of 14 days with or without cholestyramine (4 g daily). Fasting serum levels of bile acids and of 7α‐hydroxy‐4‐cholesten‐3‐one (α‐HC), a measure of endogenous bile acid synthesis, were determined by gas chromatography and high pressure liquid chromatography, respectively. In vitro, bile acid solutions were incubated for 24 h in the presence or absence of cholestyramine, and bile acid concentrations were determined in the supernatant.

Results

Simultaneous administration of UDCA and cholestyramine in man led to a decrease of fasting serum levels of UDCA by 60% when compared to UDCA serum levels during administration of UDCA alone. In contrast, serum levels of endogenous bile acids were not affected and α‐HC serum levels were found increased 2.7‐fold indicating stimulation of endogenous bile acid synthesis by cholestyramine. Administration of cholestyramine and UDCA at an interval of 5 h tended to diminish the effect of cholestyramine on UDCA serum levels. In vitro, conjugated and unconjugated UDCA were effectively bound by cholestyramine both in the presence and absence of hydrophobic bile acids.

Conclusions

The results strongly support the recommendation to administer UDCA and cholestyramine at different times of day.
Lactose (mal)digestion evaluated by the 13C‐lactose digestion test
Authors: Vonk  , Lin  , Koetse  , Huang  , Zeng  , Elzinga  , Antoine  , Stellaard
Published: March 2003

Background

The prevalence of genetically determined lactase nonpersistence is based on the results of the lactose H2 breath test. This test, however, is an indirect test, which might lead to misinterpretation.

Design

We determined lactase activity in healthy Chinese and Dutch students using a novel 13C‐lactose digestion test. The cut‐off value of this test was established in a Chinese population with a homogenous genetic background of lactase nonpersistence and was compared with the results obtained in a Caucasian population. Twenty‐five grams of a 13C‐lactose solution was consumed by 12 known H2‐positive and 5 H2‐negative Chinese students and 48 Dutch students and, subsequently, 13C‐glucose concentration in plasma and H2 excretion in breath were measured.

Results

A similar 13C‐glucose response curve was found in all Chinese students. The mean response curve in the Dutch students was more pronounced (P < 0.01). The 1 h (peak) plasma 13C‐glucose concentration was the best discriminator between lactose digesting and maldigesting subjects. The cut‐off level of 2 mmol L−113C‐glucose in plasma was defined in the H2‐positive Chinese students group. Based on the 13C‐glucose response the prevalence of lactose maldigestion in the Dutch subjects was 25%; based on the lactose H2 breath test 17%.

Conclusions

Using the 13C‐lactose digestion test the results demonstrate a higher prevalence of lactose maldigestion in a Caucasian population than indicated by the results of the H2 breath test. A moderate increase in the plasma 13C‐glucose concentration after consumption of 13C‐lactose in the young adult Chinese subjects indicates a residual lactase activity in that age group, even when a positive H2 breath test result is obtained. These results indicate that the 13C‐glucose concentration in plasma more accurately reflects the small intestinal lactose digestion capacity than the lactose H2 breath test.
Expression of keratinocyte growth factor and its receptor in colorectal cancer
Authors: Otte  , Schmitz  , Banasiewicz  , Drews  , Fölsch  , Herzig
Published: March 2003

Background and aims

The mesenchymal derived keratinocyte growth factor stimulates growth, differentiation and migration of intestinal epithelial cells. In the human gastrointestinal tract an overexpression of this growth factor has been reported in inflammatory bowel disease and pancreatic cancer. In the present study we investigated expression patterns of keratinocyte growth factor and receptor in normal and neoplastic colonic mucosa and in metastases. Furthermore, biological effects on normal intestinal and colorectal cancer cell lines were determined.

Materials and methods

Expression patterns were analysed at the mRNA level by reverse transcription‐polymerase chain reaction (RT‐PCR) and at the protein level by Western blotting. Localization of ligand and receptor in normal intestinal mucosa and cancer tissue was investigated by immunohistochemistry. Mitogenic effects of keratinocyte growth factor were assayed by [3H]thymidine incorporation in normal (Intestine‐407, IEC‐6, IEC‐18) and colorectal cancer cell lines (Colo320, LoVo, SW403, SW707).

Results

mRNA expression of keratinocyte growth factor and receptor was detected in the majority of normal and cancer samples without significant alterations. At the protein level keratinocyte growth factor expression did not differ between normal and malignant specimens, whereas protein expression of the receptor was increased up to twofold in well‐ to moderately differentiated colorectal cancers. DNA synthesis was significantly stimulated by keratinocyte growth factor in all three normal intestinal cell lines, whereas this growth factor did not significantly alter the [3H]thymidine incorporation in the colorectal cancer cell lines.

Conclusion

Keratinocyte growth factor and its receptor were detected in the majority of samples from normal and neoplastic colonic mucosa, with an overexpression of the receptor seen in the more differentiated tumour samples. Keratinocyte growth factor is a strong mitogen for normal intestinal cells, whereas it is less effective in neoplastic cells.
Lymphocyte responses following open and minimally invasive thoracic surgery
Authors: Leaver  , Craig  , Yap  , Walker
Published: March 2003

Background

Immunosuppression associated with surgery may predispose to increased tumour growth or recurrence. Lymphocytes are central components of the immune network, signalling specific and non‐specific responses in tumour immunosurveillance. This study was therefore designed to compare the effects of minimally invasive and conventional approaches to major thoracic surgery on lymphocyte populations and oxidative activity.

Patients and methods

The effects of conventional and minimally invasive video‐assisted thoracic surgery (VATS) on the numbers and types of circulating lymphocytes and on lymphocyte oxidation were compared in a prospective randomized study of 41 patients undergoing lobectomy for peripheral bronchogenic carcinoma. Blood taken pre‐operatively and on days 2 and 7 post‐operatively was analysed for T (CD4, CD8), B (CD19) and natural killer (NK) (CD56, CD16) cell counts and for lymphocyte oxidative activity. Leucocyte numbers were compared with pre‐surgical values and oxidative rate with healthy donor controls.

Results

Lymphocyte counts fell after surgery; VATS was associated with less effect on circulating T (CD4) cells at 2 days and on NK lymphocytes at 7 days post‐surgery. Lymphocyte oxidation was less suppressed in the VATS group 2 days after surgery. In general, post‐surgical changes in key cells of cellular immunity were smaller in the VATS group, and recovery to normal levels was more rapid.

Conclusion

The degree of invasiveness of thoracic surgery may influence the extent of immunosuppression in patients undergoing pulmonary lobectomy for pulmonary neoplasm.
β‐adrenoceptor‐stimulated lipolysis of subcutaneous abdominal adipocytes as a determinant of fat oxidation in obese men
Authors: Imbeault  , Tremblay  , Després  , Mauriège
Published: March 2003

Background

To verify whether an impaired lipolytic capacity of subcutaneous adipocytes may contribute to low rate of fat oxidation.

Design

Relationships between adipose tissue lipolysis of subcutaneous (subc) abdominal and femoral isolated adipocytes and respiratory quotient (RQ) were investigated in 20 obese men (age: 44 ± 5 years; means ± SD) studied in a fasting state.

Results

Maximal isoproterenol‐induced lipolysis was greater in subcutaneous abdominal than in femoral fat cells even if glycerol release was corrected for variation in cell surface area (P < 0.01). On the other hand, no regional variation was observed in the adipose cell lipolytic responses to postadrenoceptor agents such as dibutyryl‐cyclic AMP, forskolin and theophylline. Maximal isoproterenol‐induced lipolysis of subc abdominal, but not of femoral adipocytes, was inversely related to RQ (r = − 0.61; P < 0.01) and positively associated to fat oxidation (r = 0.57; P < 0.01). These relationships were independent of possible confounding factors such as fat mass, fat‐free mass, waist girth and subc abdominal adipose tissue accumulation assessed by computed tomography, as maximal isoproterenol‐induced lipolysis of subcutaneous abdominal adipocytes was the only variable retained as a significant predictor of RQ levels (38% of variance) and of fat oxidation (30% of variance).

Conclusion

These results suggest that adipose tissue lipolytic activity of subc abdominal adipocytes acts as a determinant of fat oxidation in obese men.
Effect of preoperative prophylaxis with filgrastim in cancer neck dissection
Authors: Wenisch  , Werkgartner  , Sailer  , Patruta  , Krause  , Daxboeck  , Parschalk
Published: March 2003

Background

Cancer surgery is known to lead to a deterioration in host defence mechanisms and an increase in susceptibility to infection after operation. Filgrastim enhances important antimicrobial functions of neutrophils including chemotaxis, phagocytosis and oxidative killing mechanisms.

Methods

The effects of additional (all patients received perioperative 3 ′ 25 mg kg−1 cefotiam and 1 ′ 20 mg kg−1 metronidazole) preoperative prophylaxis with filgrastim (5 μg kg−1 12 h prior to surgery plus 5 μg kg−1 0 h prior to surgery) on neutrophil phagocytosis and reactive oxygen radical production and postoperative infections in 24 patients undergoing cancer neck dissection were studied. Phagocytic capacity was assessed by measuring the uptake of fluorescein isothiocyanate‐labelled Escherichia coli and Staphylococcus aureus by flow cytometry. Reactive oxygen generation after phagocytosis was estimated by determining the amount of dihydrorhodamine 123 converted to rhodamine 123, intracellularly.

Results

In the filgrastim‐treated patients a higher neutrophil phagocytic capacity was seen intraoperatively, and 1–5 days postoperative, but not prior to surgery. Reactive oxygen radical production was significantly higher in filgrastim‐treated patients prior to surgery, intraoperative and postoperative (1–5 days). 2/12 (17%) patients had postoperative infections in the filgrastim group and 9/12 (75%) patients had infections in the placebo group (P < 0.001). In particular, wound infections were recorded more often in the placebo group (1/12 vs. 6/12; P = 0.004).

Conclusion

We conclude that filgrastim enhances perioperative neutrophil function and could be useful in the prophylaxis of postoperative wound infections in patients undergoing cancer neck dissection.
Mannose‐binding lectin promoter and structural gene variants in sarcoidosis
Authors: Foley  , Mullighan  , McGrath  , Pantelidis  , Marshall  , Lympany  , Welsh  , Du Bois
Published: March 2003

Background

Sarcoidosis is a chronic granulomatous disease of unknown aetiology. Studies have suggested that the causative agent may be an infectious micro‐organism. The mannose binding lectin (MBL) is involved in innate immunity to a wide range of micro‐organisms. Mutations in the promoter region and exon 1 of the MBL gene occur with high frequency and are associated with reduced serum levels of MBL and increased susceptibility to microbial diseases. This study investigated whether MBL variants predispose to sarcoidosis by increasing their susceptibility to micro‐organisms.

Methods

MBL gene promoter and exon 1 variants were detected by sequence specific primer polymerase chain reaction (SSP‐PCR) in 167 UK Caucasian sarcoidosis patients and 164 control subjects. Severity of pulmonary disease outcome among patients was assessed by radiography after a minimum of 4 years from disease onset and classified as mild, moderate, and severe disease categories, accordingly.

Results

MBL variant frequencies were similar in patients and controls studied. Among sarcoidosis patients, the frequencies of variants were similar regardless of severity of disease outcome. The average patient ages at time of diagnosis were similar for all MBL genotypes.

Conclusions

MBL gene variants do not appear to influence susceptibility to sarcoidosis, age of disease onset, or severity of disease.
The expression of OX40 in immunologically mediated diseases of the gastrointestinal tract (celiac disease, Crohn's disease, ulcerative colitis)
Authors: Stüber  , Büschenfeld  , Lüttges  , Von Freier  , Arendt  , Fölsch
Published: March 2003

Background

The membrane bound receptor OX40 (CD134) — a member of the TNF‐R/NGF‐R superfamily — is expressed on activated CD4+‐T cells in humans and rodents. The interaction of OX40 with its ligand (OX40L) has been shown to be important in T‐cell dependent B cell‐stimulation and T‐cell costimulation in vitro and in vivo. Several studies in experimental animal models for immunologically mediated GI‐diseases have stressed the important role of the OX40–OX40L interaction for their manifestations. To assess if the OX40–OX40L interaction is also crucial in the pathogenesis of immunologically mediated diseases of the human gastrointestinal tract (e.g. celiac disease, Crohn's disease, ulcerative colitis) we investigated, in a first line of experiments, the expression of OX40 in biopsy specimens of patients suffering from these diseases.

Methods

The biopsies were formalin fixed and paraffin‐embedded and cut into 5 μm slides. To demask the antigen, the slides were consecutively cooked in citrate buffer for 20 min. Binding of anti‐OX40 antibody was detected using the alkaline phosphatase‐anti‐alkaline phosphatease (APAAP) method.

Results

Nine of 11 biopsy specimens of patients with celiac disease were OX40‐positive; none of the 20 control duodenal biopsies demonstrated OX40‐positivity; and all biopsies of patients with ulcerative colitis (n = 11) or Crohn's disease (n = 11), respectively, stained positively for OX40. One of the 20 control biopsies showed OX40 staining.

Discussion

OX40 is highly expressed in the gastrointestinal tissue of patients with immunologically mediated bowel diseases. Together with previous studies in animal models for these diseases, the present results point to a potential role of OX40 in their pathogenesis.
Phenylalanine inhibition of the phosphorylation of cytoskeletal proteins from cerebral cortex of young rats is prevented by alanine
Authors: Carreras  , De Mattos‐Dutra  , Meirelles  , Da Rocha  , Wannmacher  , Pessoa‐Pureur
Published: March 2003

Background

Phenylalanine has been considered the main responsible agent for the brain damage that occurs in phenylketonuria.

Methods and Results

In this work we studied the effect of this amino acid on the in vitro phosphorylation of cytoskeletal proteins of the cerebral cortex of rats. We observed that 2 mM phenylalanine, a concentration usually found in the plasma of phenylketonuric patients, decreased the in vitro32P incorporation into these proteins. In addition, we investigated the effect of alanine on the inhibition of 32P incorporation into cytoskeletal proteins caused by phenylalanine. We observed that 0.5 m
m alanine did not alter 32P incorporation but prevented the inhibition provoked by phenylalanine.

Conclusion

In case the inhibition of cytoskeletal protein phosphorylation by phenylalanine also occurs in human phenylketonuria, it is possible that alanine supplementation to the phenylalanine‐restricted diet may be beneficial to these patients.
[11C]Hyaluronan uptake with positron emission tomography in liver disease
Authors: Lindqvist  , Westerberg  , Bergström  , Torsteindottir  , Gustafson  , Sundin  , Lööf  , Långström
Published: March 2003

Background

A hyaluronan‐loading test has been developed for assessment of hyaluronan kinetics and applied in patients with liver and joint diseases. This test describes the metabolic process of hyaluronan but cannot define the specific contribution of different organs. A method for labelling of hyaluronan with the short‐lived positron‐emitting radionuclide 11C has been published and in this study applied in healthy subjects and liver diseases.

Materials and methods

Positron emission tomography (PET) was used for the regional assessment and quantification of [11C]hyaluronan uptake in three healthy subjects, four patients with alcoholic liver cirrhosis, one with alcoholic hepatitis and one with liver steatosis. After intravenous administration of 60 MBq of 11C‐labelled hyaluronan, a 55‐min PET scan was performed over the liver and plasma radioactivity was analysed. Rate constants describing the transport of the [11C]hyaluronan tracer from plasma to the liver were calculated.

Results

High uptake was observed in the liver combined with a rapid elimination of tracer from plasma. The liver uptake rate (k1) was significantly lower in patients (0.018 min−1) than in healthy subjects (0.043 min−1, P = 0.002). The rate constants seem to be related to the severity of the disease as defined by the Child–Pugh score.

Conclusions

The study suggests that PET with [11C]hyaluronan could be an accurate method by which to assess liver dysfunction, in conditions where endothelial cell function is impaired. The possibility of quantification over extended portions of the body also opens up possibilities to explore regional differences in liver function and to assess other elimination routes of hyaluronan.
Semi‐starvation alters myofibrillar mRNA concentrations to expedite rapid recovery of muscle protein stores following feeding
Authors: Svanberg  , Kiri  , Isgaard  , Goldspink
Published: March 2003

Background

Protein synthesis in skeletal muscle is reduced following starvation and restored by feeding. The mediators and mechanisms are incompletely understood. The aim of this study was to evaluate whether prolongation of undernutrition induced changes in muscle gene expression at the level of mRNA and protein.

Materials and methods

The changes in myosin heavy‐chain 2X mRNA in adult partially starved (50% of ad libitum standard rodent chow intake for 4 or 7 days) C57BL mice or subsequently refed mice were studied. Ad libitum‐fed mice were used as controls. Protein synthesis, total RNA and myosin heavy‐chain 2X mRNA concentrations were determined. Plasma concentrations of amino acids were measured by high‐performance liquid chromatography.

Results

Partial starvation of 4 and 7 days reduced body weight by 15.6 ± 1% and 17.1 ± 2.1% (P ≤ 0.05) vs. ad libitum fed controls. Protein synthesis was reduced by 32 ± 9% and protein content by 20 ± 4% (P ≤ 0.05) following 7 days of partial starvation. Plasma amino acid concentrations were increased (6297 ± 853) in refed animals vs. ad libitum‐fed controls (3057 ± 141, P ≤ 0.05). Total RNA concentration (μg RNA μg−1 DNA) in skeletal muscle was unchanged. Myosin heavy‐chain 2X mRNA concentration did not change following 4 days of partial starvation but increased by 24 ± 5% (P ≤ 0.05) following 7 days of partial starvation, hence suggesting that expression of myosin mRNA was nutritionally altered.

Conclusion

Postprandial stimulation of protein synthesis following starvation may thus be a combination of increased mRNA availability and increased translation. This effect may be activated by peak concentrations of amino acids in plasma following feeding.
Protein sgp 120 as a marker of an acquired angioedema
Authors: Paranos S. , Nikolic G.
Published: March 2003

Background

Angioedema is not an event peculiar to an acute‐phase response. We registered the appearance of angioedema in four nonatopic patients suffering from diverse inflammatory stimuli.

Materials and methods

Serum concentrations of C‐reactive protein (CRP), haptoglobin, α1‐antitrypsin, α2‐macroglobulin, C3, C4, C1INH and protein sgp 120 (classified as a regulatory protein of the complement system) were assessed over 7 consecutive days, beginning with the onset of angioedema in these four patients.

Results

Instead of returning to the normal level, CRP peaked again on the 4th day (A‐test, P < 0.05) and declined significantly by the 7th day (A‐test, P < 0.05). Serum levels of sgp 120, C3c and C1INH increased gradually up to the 5th day but only sgp 120 was significantly raised in relation to the initial value (P < 0.05).

Conclusion

In our patients, we registered four diverse profiles of the acute‐phase proteins (Kruskal–Wallis test, P < 0.05) probably due to the diverse nature of the pre‐existing inflammatory stimuli. According to these results, the unexpected appearance of angioedema implies the contribution of sgp 120 as the main source of fragments with kinin‐like properties.
α‐tocopherol improves impaired physiology of rat type II pneumocytes isolated from experimentally injured lungs
Authors: Müller B. , Hochscheid R. , Seifart C. , Barth P. J.
Published: March 2003

Background

Oxidant stress delivered by nitrogen dioxide (NO2) inhalation impairs the function of extracellular surfactant as well as surfactant phospholipid metabolism in type II pneumocytes. Because protection against oxidant stress is important to normal lung function, the lung contains a variety of antioxidants, including vitamin E. Whether administration of this antioxidant during NO2 inhalation attenuates NO2‐induced alterations in phospholipid metabolism in type II pneumocytes has not been studied.

Methods

We exposed rats to identical NO2 body doses (720 p.p.m. x h) using continuous, intermittent, or repetitive protocols. During exposure periods, the animals received daily intramuscular injections of vitamin E (25 mg kg−1). We isolated type II pneumocytes from NO2‐exposed rats and evaluated them for cell yield and viability, as well as for synthesis and secretion of phosphatidylcholine (PC) as measures of surfactant metabolism.

Results

The yield of type II pneumocytes was significantly elevated from animals that had been exposed continuously to NO2 whereas in intermittently and repeatedly exposed rats, cell yield was similar to yield from control animals. Viability of the isolated cells was similar in controls and all NO2 exposure protocols. Vitamin E treatment of the NO2‐exposed rats neither changed cell yield nor cell viability. Phospholipid de novo synthesis, as estimated by choline incorporation into PC, was increased most after continuous NO2 inhalation whereas in the other conditions there was only a slight increase. Vitamin E administration further increased phospholipid synthesis; this difference reached statistical significance only in the case of intermittent NO2 exposure. Secretion of phosphatidylcholine from type II cells was only reduced after continuous NO2 inhalation and administration of the antioxidant reduced the impairment.

Conclusion

Because vitamin E appears to preserve the ability of type II pneumocytes isolated from NO2‐exposed rats to synthesize and secrete surfactant lipid, we conclude that administration of vitamin E may mitigate NO2‐induced lung injury.
Role of homocysteine, cystathionine and methylmalonic acid measurement for diagnosis of vitamin deficiency in high‐aged subjects
Authors: Herrmann W. , Schorr H. , Bodis M. , Knapp J. P. , Müller A. , Stein G. , Geisel J.
Published: March 2003

Intracellular B‐vitamin and folate deficiency indicated by hyperhomocysteinemia is very frequent in the elderly population. Hyperhomocysteinemia increases the risk of atherothrombotic diseases and neuropsychiatric complications. Our aim was to evaluate the prevalence of increased serum metabolite concentrations in subjects of a higher age, and whether the measurement of metabolite concentrations is more effective in diagnosing B‐vitamin deficiency than mere homocysteine.

Homocysteine (HCY), cystathionine (CYS) and methylmalonic acid (MMA) were investigated in serum together with vitamin B‐12, B‐6 and folate in 90 high‐aged subjects (85–102 years), 92 seniors (65–75 years), and in 50 younger subjects (19–50 years).

Elderly subjects (high‐aged and senior) had elevated serum concentrations of metabolites. High‐aged subjects had a higher frequency of pathological increases than seniors: HCY 62% vs. 24%; MMA 62% vs. 23%; CYS 81% vs. 36%. Folate and vitamin B‐6 concentrations were significantly decreased in both elderly groups; vitamin B‐12 was only decreased in high‐aged subjects. Utilising vitamin B‐6, B‐12 and folate for diagnosis of intracellular vitamin deficiency, the rate was 30% in seniors and 55% in high aged subjects. However, utilising the metabolites (HCY, MMA and CYS) for the diagnosis of intracellular vitamin deficiency, there was a distinctly increased rate of 55% in seniors respective to 90% in high‐aged subjects. Backward multiple regression analysis revealed that only folate, MMA, creatinine and age were independent variables influencing the HCY concentration. Furthermore, the MMA concentration was significantly and independently influenced by folate, vitamin B‐12, HCY and creatinine, and the serum concentration of CYS by vitamin B‐12, creatinine and age.

The metabolites HCY, MMA and CYS are sensitive indicators diagnosing impaired remethylation of homocysteine to methionine with parallel activation of catabolic pathway. Compared to mere HCY or B‐vitamins in serum, the efficiency of diagnosing a disturbed HCY metabolism increases very much in utilising the metabolites HCY, MMA and CYS. For differential diagnosis, parallel measurement of folate and creatinine is recommended. The early and correct diagnosis of B‐vitamin deficiency in elderly subjects is of high clinical relevance.
Nitric oxide inhibition intensifies the depressant effect of cocaine on the left ventricular function in anaesthetized pigs
Authors: Roig E. , Melis G. , Heras M. , Rigol M. , Epelde F. , DeCandia G. , Sanz G.
Published: March 2003

Myocardial ischaemia and left ventricular dysfunction have been described in cocaine users. Whether nitric oxide (NO) inhibition may potentiate the effects of cocaine on coronary circulation and ventricular function is still unknown.

In order to test this hypothesis, 38 pentobarbital‐anaesthetized pigs were instrumented for systolic blood pressure, coronary blood flow, left ventricular dp/dt, cardiac output, left ventricular end‐diastolic and end‐systolic lengths and shortening fraction. The pigs were randomized into three groups: control group: i.v. saline (n = 5); group 1: i.v. cocaine, 10 mg kg−1 over 20 min (n = 17); group 2: the same doses of cocaine 30 min after i.c. L‐NAME 20 µg/kg min−1 infusion (n = 16). In order to know whether the observed effects were specific of NO inhibition, in five pigs i.c.
l‐arginine was simultaneously infused with L‐NAME, in five pigs i.c. NTG, an endothelial‐independent vasodilator, was simultaneously infused with L‐NAME before cocaine was administered, and in nine additional pigs the proximal left anterior descending (LAD) flow was reduced to around 20% of the basal value by means of a mechanical occluder before cocaine was administered.

Cocaine i.v did not change the coronary blood flow, while it induced a significant reduction in cardiac output, left ventricular dp/dt and shortening fraction (15 ± 4–8 ± 4%, P < 0.05). When cocaine was administered after L‐NAME infused i.c. during 30 min
, a significantly more severe reduction of the shortening fraction (12 ± 3–4 ± 2%, P < 0.0001) was induced; this effect was abolished by simultaneous perfusion of
l‐arginine i.c. NTG. The results when cocaine was administered after the 20% LAD flow reduction by mechanical occluder did not differ from those of cocaine alone.

NO inhibition intensifies the cocaine‐induced left ventricular dysfunction.
Increased erythropoietin synthesis in patients with COLD or left heart failure is related to alterations in renal haemodynamics
Authors: Pham I. , Andrivet P. , Sediame S. , Defouilloy C. , Moutereau S. , Wirquin V. , Chouaïd C. , Housset B. , Adnot S.
Published: March 2003

The mechanisms controlling erythropoietin (EPO) synthesis by the kidney in patients with chronic obstructive lung disease (COLD) or congestive left heart failure (CLHF) remain incompletely understood. Renal dysfunction occurs as a consequence of decreased renal blood flow (RBF) in these diseases. Because alterations in renal haemodynamics may affect EPO synthesis and red blood cell production, we investigated the potential relationships between renal function and plasma EPO synthesis in patients with COLD or CLHF.

Thirty‐two patients with COLD and 13 with CLHF underwent determination of renal physiology parameters, plasma EPO levels and haemoglobin levels.

Plasma EPO concentrations were increased in patients with COLD or CLHF as compared to normal subjects, and were inversely correlated to haemoglobin concentrations. In patients with COLD or CLHF, plasma EPO was negatively correlated with both RBF and renal oxygen delivery (ROD) and positively correlated with filtration fraction. Plasma EPO was not correlated with glomerular filtration rate, fractional excretion of sodium, Po2 or Pco2. Among the patients with COLD, those with polycythemia (haemoglobin > 150 g L−1) had lower plasma EPO and higher RBF and ROD values than those with normocythemia (haemoglobin ≤ 150 g L−1).

Taken together, our data suggest that in patients with COLD or CLHF the critical determinant for EPO production is impairment of renal haemodynamics.
Haemostatic profile in hypothyroidism as potential risk factor for vascular or thrombotic disease
Authors: Müller B. , Tsakiris D. A. , Roth C. B. , Guglielmetti M. , Staub J.‐J. , Marbet G. A.
Published: March 2003

The influence of thyroid failure on haemostasis is controversial, both hypocoagulable and hypercoagulable states have been reported. Since both subclinical and overt hypothyroidism have been associated with atherosclerosis, a hypercoagulable state in addition might represent a risk factor for thromboembolic disease.

We investigated various haemostatic variables in 42 women with subclinical hypothyroidism and compared them to 66 euthyroid controls. Prothrombin time, activated partial thromboplastin time, fibrinogen, factor VII activity (FVII:C), factor VII antigen (FVII:Ag), factor VIII activity, von Willebrand factor (vWF), antithrombin III, heparin cofactor II, protein C, protein S, plasminogen, antiplasmin, plasminogen activator inhibitor and tissue plasminogen activator, as well as common lipid variables, were measured.

Factor VII:C (P < 0·02) and the ratio FVII:C/FVII:Ag (P < 0·01) were significantly increased in subclinical hypothyroid patients compared to the control group. Both parameters remained higher in hypothyroid patients after exclusion of 18 women on oestrogen replacement therapy. No differences were found between the groups with respect to vWF or the other haemostatic and lipid variables tested.

Patients with subclinical hypothyroidism had significantly higher levels of FVII:C. The greater increase in FVII:C compared to that of FVII:Ag, as shown by the increase in their ratio, might reflect the presence of activated FVIIa. This might mean a hypercoagulable state, which could contribute to the increased prevalence of coronary heart disease reported in such patients. A hypercoagulable state might be another argument in favour of thyroxine replacement treatment in subclinical hypothyroidism, especially in patients with additional risk factors for vascular disease.