Failure of thrombolytic therapy in patients with myocardial infarction is associated with high plasma levels of factor VII antigen

Thrombolytic therapy in acute myocardial infarction fails to re-establish coronary blood flow in a significant number of patients. One reason for this may be haemostatic imbalance. We investigated whether coagulation factor VII antigen (FVIIag), fibrinogen and protein C were related to reperfusion. Plasma from 45 patients was drawn before treatment and reperfusion assessed by means of continuous, on-line, vector-ECG analysis. Among the 17 patients with no reperfusion, FVIIag levels were significantly higher than among the 28 with signs of reperfusion (560 vs. 410 microg/l median, p = 0.006). Protein C levels where higher in the group with successful reperfusion (1.10 vs. 1.01 U/ml median, p = 0.03), whereas no difference was seen in fibrinogen levels. The findings were not influenced by plasma-triglycerides, body-mass index, age or time between onset of chest pain and thrombolytic therapy. The results suggest that FVII is of importance for the formation as well as resolution of coronary clots.

A folate binding protein in ascitic fluid, serum and ovarian tissue of patients with ovarian adenocarcinoma immunoreacts with antibodies against human milk folate binding protein

The presence of a folate binding protein which immunoreacts with antibodies against human milk folate binding protein was demonstrated in ascitic fluids from seven patients with ovarian adenocarcinoma. Ascitic fluids collected from two patients with other malignancies contained non-immunoreactive FBP. Tumor tissue specimens from five patients with ovarian carcinoma contained immunoreactive FBP. By contrast to normal ovaries ovarian carcinoma tissue showed positive immunostaining on immunohistochemistry. Ascitic fluids from two patients with ovarian carcinoma exhibited single distinct bands on SDS-PAGE immunoblotting. The gel filtration profile of ovarian carcinoma tissue homogenate from two patients contained 25 and 1OOkDa peaks of radioligand-bound and immunoreactive folate binding protein, while ascitic fluid from one of the patients exhibited a large 100 kDa immunoreactive peak with no radioligand binding activity. The immunoreactive non-functional 100 kDa FBP could represent unprocessed precursor FBP. Future studies are necessary to evaluate whether determination of immunoreactive FBP in ovarian adenocarcinomatosis is of any diagnostic value.

A high-affinity folate binding protein in fluid of benign cysts of human liver and mammary gland

The presence of a folate binding protein in fluid of benign cysts of human liver and mammary gland was demonstrated. Radioligand binding was of a high-affinity type (K approximately 10(10) M -1). The gel filtration profile of cystic fluid contained two peaks of radiolabelled folate, a large one of 25 kDa and a small one of 100 kDa. The concentration of radioligand bound protein in samples of cystic fluid ranged from nil to 6 nM. In most cases the protein immunoreacted with antibodies against human milk folate binding protein. The data suggest that fluid of human liver and mammary gland cysts contains a folate binding protein which appears to be homologous to human milk folate binding protein.

Selectivity of superficial vein occlusion at the ankle and calf level: a methodological study in healthy volunteers

Judgement of deep venous function may be necessary before surgery for superficial vein incompetence is performed. Assessment of deep venous function needs selective entrapment of superficial venous compartments between the ankle and knee, which may not be guaranteed if conventional tourniquets are used. This study was, therefore, aimed at modifying the technique of selective compression of superficial vein compartments. Twenty apparently normal legs of 10 volunteers were investigated on two study days. The subjects were in a supine position with the feet resting 30 cm above heart level. Ankle cuffs (3 cm wide) were placed just above the malleoli and stepwise inflated with air. The steady-state venous volume of the forefoot as a function of the pressure within the ankle cuff was measured with a mercury-in-rubber strain gauge. The maximum venous outflow velocity from the foot was also measured at each cuff pressure step after the addition of conventional thigh vein occlusion. The same protocol was used on the second study day: calf cuffs (3 cm wide) were then used instead of the ankle cuffs. In the forefoot, venous volume increased and the maximum venous outflow velocity decreased significantly either at ankle cuff pressures > 30 mmHg or at calf cuff pressures of > 60 mmHg. By using small cuffs, selective superficial vein occlusion seems to occur at cuff pressures ranging between 10 and 30 mmHg (ankle) and between 30 and 60 mmHg (calf), provided the feet are 30 cm above heart level. Higher cuff pressures seem to interact with deep venous function.

Identification and analysis of macrophage-derived foam cells from human atherosclerotic lesions by using a "mock" FL3 channel in flow cytometry

Macrophages are one of the major cell types in atherosclerotic lesions. They are believed to play an important role in the pathogenesis and development of the lesion, but their functional state and phenotypic characteristics are not well understood. Using flow cytometry, we analyzed surface markers of macrophages extracted from tissue digests. However, conventional techniques were hampered by the abundance of cell debris and extracellular lipids, which co-localized with double-positive cells in all fluorescent plots. We therefore developed a method to overcome this problem by using a novel gating technique in multiparameter flow cytometry. This method utilized the third fluorescence channel (FL3) as a "mock" channel, since no antibody conjugated to an FL3-specific fluorochrome was added to the samples. Cells single-positive for macrophage-specific monoclonal antibodies (mAb) conjugated to phycoerythrin (PE) (FL2) were separated from non-specific fluorescent particles in the FL2 versus FL3 fluorescent plot and a region excluding debris could be set. This was then used as a gate to exclude debris also in the first fluorescence channel (FL1) vs. FL2 plot in which expression of a panel of activation markers identified by fluorescein isothiocyanate (FITC)-conjugated mAb was analyzed. Using this strategy, we were able to identify and analyze the phenotype of macrophages from human atherosclerotic lesions. We were also able to sort these cells and in this way obtained a preparation of macrophage-derived foam cells from the tissue with little contamination of debris.

Folate receptors in malignant and benign tissues of human female genital tract

We have characterized the folate receptor in malignant and benign tissues of human female genital tract (Fallopian tube and benign and malignant tissues of uterus). Radioligand binding displayed characteristics similar to those of other folate binding proteins. Those include a high-affinity type of binding (K = 10(10)M-1), apparent positive cooperativity, a slow dissociation at pH 7.4 becoming rapid at pH 3.5, and inhibition of binding by folate analogues. The gel filtration profile of Triton X-100 solubilized tissue contained two large peaks of 3H-folate labelled protein (> = 130 and 100 kDa) as well as a 25 kDa peak. Only a single band of 70 kDa was seen on SDS-PAGE immunoblotting. The large molecular size forms on gel filtration appear to represent folate receptors having a hydrophobic membrane anchor inserted into Triton X-100 micelles. The folate receptor of female genital tract showed cross-reactivity in ELISA and positive immunostaining with rabbit antibodies against human milk folate binding protein. Variations in the ratio of immunoresponse to total high affinity folic acid binding suggests the presence of multiple isoforms of the receptor in different types of malignant and benign tissues.

A common thrombomodulin amino acid dimorphism is associated with myocardial infarction

Endothelial dysfunction and haemostatic imbalance are believed to be important aetiological factors in the development of acute coronary syndromes. Thrombomodulin (TM) is an integral membrane protein crucial for normal endothelial function and activation of the protein C anticoagulant pathway. We have investigated the importance of a common C/T dimorphism in the TM gene (nucleotide 1418) for development of premature myocardial infarction (MI). The C/T dimorphism predicts an Ala455 to Val replacement in the sixth EGF-like domain of TM. The dimorphism was investigated in 97 MI survivors and 159 healthy controls. The C allele was significantly more frequent among patients than controls (p = 0.035). The allele frequency for the C allele was 0.82 in the patients and 0.72 in the control group. The plasma concentration of TM was investigated among healthy controls but was not related to the C/T dimorphism. In conclusion, the association of the C allele with premature MI, suggests that the TM gene and the C/T dimorphism may be aetiological factors involved in the pathogenesis of MI. Possibly, the Ala455 to Val replacement may affect the function of the TM molecule and the activation of the protein C anticoagulant pathway.

[Anastomotic leakage after low anterior resection for rectal cancer]

A series of 377 consecutive patients were operated upon with low anterior resection for rectal cancer in the nine Danish departments of surgical gastroenterology during 1992-1993. A retrospective analysis was carried out to calculate the frequency of anastomotic leakage and to evaluate factors of potential influence on the development of leakage according to the literature. Sixty-three patients (17%) developed leakage, which was followed by an increased mortality within the first three postoperative months. Only two variables significantly influenced the leakage rate: male gender was associated with a higher leakage rate (p = 0.02), whereas departments with a low number of rectal cancer surgeons had a low rate of anastomotic leakage (p = 0.02). In conclusion, the rather high frequency of anastomotic leakage calls for further clinical and pathogenetic research in this field. Until then, we recommend the routine use of a peroperative leakage test and selective use of prophylactic ostomy in cases of unsatisfactory anastomosis. Furthermore, it is recommended that low anterior resection for rectal cancer is limited to few surgeons in each department in order to ensure a uniform quality and hopefully also thereby reduce the rate of anastomotic leakage.

Characterization of the folate receptor in human molar placenta

We have characterized a high-affinity folate receptor in human molar placenta tissue. Radioligand binding exhibited characteristics typical of other high-affinity folate binding proteins. Those included, positive cooperativity, a tendency to increased binding affinity with decreasing receptor concentration, a slow ligand dissociation at pH 7.4 becoming rapid at pH 3.5, and inhibition by folate analogues. The folate receptor cross-reacted with antibodies against human milk folate binding protein, e.g. the syncytothrophoblastic layer of molar placenta tissue sections showed strongly positive immunostaining. The gel filtration profile contained two radioligand-bound peaks (25 and 100 kDa), however, with considerable overlap. Only a single band of 70 kDa was seen on SDS-PAGE immunoblotting. The folate receptor in placental tissue may play a crucial role in the transfer of folate from maternal circulation to the fetus.

Retinol-binding protein and transferrin in urine. New markers of renal function in essential hypertension and white coat hypertension?

We studied the 24 h urinary excretion of albumin, transferrin, immunoglobulin G, and retinol-binding protein in individuals with essential hypertension, white coat hypertension, and normotension. In 56 individuals, we measured the 24 h ambulatory blood pressure (AMBP). The individuals could be divided into three groups: 26 hypertensives, 14 white coat hypertensives, and 16 normotensives. Daytime AMBP values were (median values with range in parentheses, mm Hg): hypertensives 158/105 (198 to 121/95 to 120), white coat hypertensives 141/83 (161 to 129/72 to 90), and normotensives 123/75 (148 to 102/63 to 86). We determined with immunochemical methods the 24 h urinary excretions of albumin, transferrin, and immunoglobulin G, all markers of glomerular dysfunction, and retinol-binding protein, a marker of impaired proximal tubular function. We found a significantly higher excretion of albumin and transferrin in hypertensives (P < .0000/P < .0001) and in white coat hypertensives (P < .003/P < .02) compared to normotensives. Out of 26 hypertensives, seven had microalbuminuria (> or = 30 to < 300 mg albumin/ 24 h). Two cases of microalbuminuria were found among the 14 white coat hypertensives. Immunoglobulin G excretion was not significantly increased in any of the hypertensive groups. Retinol-binding protein excretion was significantly higher in hypertensive patients (P < .007), whereas no elevation was observed in persons with white coat hypertension. In hypertensives, a significant correlation was found between urinary excretion of albumin and transferrin and office blood pressure and systolic AMBP. There was no significant correlation between the urinary excretions of IgG and retinol-binding protein and blood pressures in any of the three groups. Our findings indicate that patients with white coat hypertension, like hypertensives, have a selective type of glomerular dysfunction. However, proximal tubular dysfunction was seen only in hypertensives. Urinary excretions of albumin, transferrin, and retinol-binding protein may be useful as markers of glomerular and tubular dysfunction in essential hypertension.

Structural features of a close homologue of L1 (CHL1) in the mouse: a new member of the L1 family of neural recognition molecules

We have identified a close homologue of L1 (CHL1) in the mouse. CHL1 comprises an N-terminal signal sequence, six immunoglobulin (Ig)-like domains, 4.5 fibronectin type III (FN)-like repeats, a transmembrane domain and a C-terminal, most likely intracellular domain of approximately 100 amino acids. CHL1 is most similar in its extracellular domain to chicken Ng-CAM (approximately 40% amino acid identity), followed by mouse L1, chicken neurofascin, chicken Nr-CAM, Drosophila neuroglian and zebrafish L1.1 (37-28% amino acid identity), and mouse F3, rat TAG-1 and rat BIG-1 (approximately 27% amino acid identity). The similarity with other members of the Ig superfamily [e.g. neural cell adhesion molecule (N-CAM), DCC, HLAR, rse] is 16-11%. The intracellular domain is most similar to mouse and chicken Nr-CAM, mouse and rat neurofascin (approximately 60% amino acid identity) followed by chicken neurofascin and Ng-CAM, Drosophila neuroglian and zebrafish L1.1 and L1.2 (approximately 40% amino acid identity). Besides the high overall homology and conserved modular structure among previously recognized members of the L1 family (mouse/human L1/rat NILE; chicken Ng-CAM; chicken/mouse Nr-CAM; Drosophila neuroglian; zebrafish L1.1 and L1.2; chicken/mouse neurofascin/rat ankyrin-binding glycoprotein), criteria characteristic of L1 were identified with regard to the number of amino acids between positions of conserved amino acid residues defining distances within and between two adjacent Ig-like domains and FN-like repeats. These show a collinearity in the six Ig-like domains and four adjacent FN-like repeats that is remarkably conserved between L1 and molecules containing these modules (designated the L1 family cassette), including the GPI-linked forms of the F3 subgroup (mouse F3/chicken F11/human CNTN1; rat BIG-1/mouse PANG; rat TAG-1/mouse TAX-1/chicken axonin-1). The colorectal cancer molecule (DCC), previously introduced as an N-CAM-like molecule, conforms to the L1 family cassette. Other structural features of CHL 1 shared between members of the L1 family are a high degree of N-glycosidically linked carbohydrates (approximately 20% of its molecular mass), which include the HNK-1 carbohydrate structure, and a pattern of protein fragments comprising a major 185 kDa band and smaller fragments of 165 and 125 kDa. As for the other L1 family members, predominant expression of CHL1 is observed in the nervous system and at later developmental stages. In the central nervous system CHL1 is expressed by neurons, but, in contrast to L1, also by glial cells. Our findings suggest a common ancestral L1-like molecule which evolved via gene duplication to generate a diversity of structurally and functionally distinct yet similar molecules.

Effect of milk processing on the concentration of folate-binding protein (FBP), folate-binding capacity and retention of 5-methyltetrahydrofolate

The main objective of this study was to investigate the effects of pasteurisation, UHT processing and fermentation on the concentration of folate-binding proteins (FBP) and their folate binding capacity in comparison with the retention of the most predominant folate from, 5-CH3THF. The amount of folate-binding protein (FBP) was analysed using enzyme-linked immunosorbent assay (ELISA). Unprocessed milk and pasteurised milk were found to contain similar amounts, 211 and 168 nmol/l, of FBP, respectively. UHT-processed milk and Yoghurt naturelle, both processed at temperatures above 90 degrees C, contained only 5.2 and 0.2 nmol/l FBP, respectively. As an indication of the protein-binding capacity free and protein-bound folates were analysed after charcoal treatment using the radio-protein binding assay method (RPBA). These results indicated that all folates in unprocessed milk and pasteurised milk were protein-bound, while folates in UHT-processed milk and Yoghurt naturelle occurred freely which is supported by our findings on FBP. High-performance liquid chromatography analysis indicated that unprocessed milk, pasteurised milk, UHT-processed milk and Yoghurt naturelle contained 44.8 +/- 2.1 (n = 10), 41.1 +/- 0.9 (n = 10), 36.1 +/- 1.8 (n = 10) and 35.6 +/- 9.1 micrograms/l (n = 10) 5-methyltetrahydrofolates (5-CH3THF), respectively, after deconjugation. Corresponding values for total milk folates analysed using radio-protein binding assay were 80.4 +/- 0.9 (n = 10), 64.2 +/- 2.7 (n = 10), 48.2 +/- 1.8 (n = 10) and 54.0 +/- 8.2 micrograms/l (n = 10), respectively. Hence, both methods indicated significant (P < 0.05) losses of 5-CH3THF as a result of pasteurisation, UHT processing and fermentation, compared with unprocessed milk. In spite of apparent discrepancies in folate concentrations obtained using the two different methods, these results support the equimolar ratio of FBP and folates in unprocessed and pasteurised milk when data on 5-CH3THF, obtained using HPLC were corrected for differences in recovery. Thus, heat processing of milk not only reduced the amount of 5-CH3 THF significantly, but also changed the concentration of FBP and the folate-binding capacity of FBP, which may have implications on the bioavailability of milk folates.

Phosphorus-31 MR spectroscopy in the preoperative evaluation of symptomatic unilateral carotid artery stenosis

PURPOSE

The purpose of this study was to examine the potential of 31P-MRS (MR spectroscopy) in the pre- and postoperative evaluation of patients referred for endarterectomy.

MATERIAL AND METHODS

Nine patients with unilateral, hemodynamically significant stenosis in the region of the common carotid bifurcation were examined pre- and post-operatively with CT, SPECT (regional cerebral blood flow), transcranial Doppler, and duplex sonography, and they also underwent neuropsychologic investigation. Phosphorus-31 MRS of each hemisphere was performed before and 27-148 days after surgery. The relative concentrations of phosphomono- and -diesters, inorganic phosphate, phosphocreatine, and ATP were estimated.

RESULTS

No definite changes in concentrations could be detected for any of the metabolites.

CONCLUSION

The lack of changes was probably due to well-functioning collaterals and to the partial volume effect, whereby changes in a focal region are hidden when larger volumes are studied.

Prevalence of factor V gene mutation amongst myocardial infarction patients and healthy controls is higher in Sweden than in other countries

OBJECTIVE

Haemostatic imbalance may be an aetiological factor in the development of acute coronary syndromes. Inherited resistance to activated protein C (APC) is a common disorder associated with hypercoagulability and lifelong risk of venous thrombosis. APC resistance is due to a single mutation in the gene coding for coagulation factor V (FV:Q506). To test the importance of the FV:Q506 mutation in premature myocardial infarction (MI), its prevalence was investigated in Swedish patients with MI before the age of 50 years.

DESIGN, SETTING AND SUBJECTS

In a retrospective case-control study, the FV:Q506 mutation was investigated in 101 survivors of MI (79 men, 22 women) and in 101 healthy sex- and age-matched controls.

MAIN OUTCOME MEASURE

The prevalence of FV:Q506 mutation.

RESULTS

The FV:Q506 mutation was found in 18% of patients versus 11% of controls (P = 0.16). The mutation was significantly more frequent amongst male patients than amongst controls (23 vs. 10%; P = 0.03), the calculated odds ratio being 2.6 (95% CI, 1.1-6.4).

CONCLUSION

The high prevalence of the FV:Q506 mutation found amongst Swedish MI patients, especially amongst men, is noteworthy, and calls for further studies on the outcome of MI in APC-resistant patients. The prevalence of the FV:Q506 mutation in controls is higher than figures reported from other countries, suggesting that at least 10% of the Swedish population are carriers of a congenital prothrombotic disorder.

Erectile dysfunction in men with chronic medical illness

This study examined interrelationships of psychosocial variables found in a psychological evaluation for erectile disorder in 75 male veterans with chronic medical illness. Patients whose partners participated in the evaluation were compared with those whose partners were not involved, and agreement on measures between patients and partners was examined. Finally, a principal components analysis was performed to assess the primary dimensions underlying the variance in mental health and sexual functioning variables. Five factors were identified, accounting for 65.5% of the variance. Results of these analyses are discussed in order to obtain an understanding of the interrelationship between behavioral, psychological, and interpersonal variables in the onset and course of sexual dysfunction.

Elevated levels of prothrombin activation fragment 1 + 2 in plasma from patients with heterozygous Arg506 to Gln mutation in the factor V gene (APC-resistance) and/or inherited protein S deficiency

Inherited resistance to activated protein C (APC-resistance), caused by a point mutation in the factor V gene leading to replacement of Arg(R)506 with a Gln (Q), and inherited protein S deficiency are associated with functional impairment of the protein C anticoagulant system, yielding lifelong hypercoagulability and increased risk of thrombosis. APC-resistance is often an additional genetic risk factor in thrombosis-prone protein S deficient families. The plasma concentration of prothrombin fragment 1 + 2 (F1 + 2), which is a marker of hypercoagulable states, was measured in 205 members of 34 thrombosis-prone families harbouring the Arg506 to Gln mutation (APC-resistance) and/or inherited protein S deficiency. The plasma concentration of F1 + 2 was significantly higher both in 38 individuals carrying the FV:Q506 mutation in heterozygous state (1.7 +/- 0.7 nM; mean +/- SD) and in 48 protein S deficient cases (1.9 +/- 0.9 nm), than in 100 unaffected relatives (1.3 +/- 0.5 nM). Warfarin therapy decreased the F1 + 2 levels, even in those four patients who had combined defects (0.5 +/- 0.3 nM). Our results agree with the hypothesis that individuals with APC-resistance or protein S deficiency have an imbalance between pro- and anti-coagulant forces leading to increased thrombin generation and a hypercoagulable state.

Effects of masticatory muscle function on bone mass in the mandible of the growing rat

The effect of altered masticatory muscle function on bone mass at different sites in the rat mandible was studied using aluminium as a reference substance in computer-assisted image analysis. Forty-two growing male rats were divided into three groups, of which one group was killed at the beginning of the experiment to provide baseline values. Of the remaining two, one received a hard diet (control group) and the other a soft diet. After 28 days the rats were killed and the mandibles were excised. Lateral radiographs were taken of the mandible halves together with an aluminium stepwedge and then analysed by an image analysis system. Radiographic bone mass was measured in the transverse plane as "aluminium-equivalent thickness' in millimetres. Standardized areas were chosen to investigate regions with different functional demands. Significant differences were found between the groups in the alveolar bone of the molars and the incisor, as well as in the condylar costa and the condylar process. Significant differences were also found in some areas related to muscle insertion, such as the anterior lower border of the ramus, whereas no statistically significant differences could be found in others, such as the posterior lower border of the angular process. In conclusion, altered masticatory function influences the amount of bone mass in certain parts of mandible, where changes in applied bending forces have possibly altered the bone strain.

A high-affinity soluble folate receptor in fluids of non-neoplastic ovarian cysts: radioligand binding, molecular size, hydrophobic residue, and immunological properties

The presence of a soluble folate receptor in fluids of non-neoplastic ovarian cysts was demonstrated. Radioligand binding exhibited characteristics typical of high-affinity folate-binding proteins. These included positive cooperativity, a tendency to increased binding affinity with decreasing receptor concentration, a slow ligand dissociation at pH 7.4 and inhibition by folate analogues. The folate receptor was probably synthesized in the lining epithelial cells of the cysts which showed positive immunostaining with antibodies against human milk folate-binding protein. The gel filtration profile of cystic fluid contained two radioligand-bound peaks, 25 and 100 kDa, whereas a single band of 70 kDa was seen on SDS-PAGE immunoblotting. Treatment with the enzyme phosphatidylinositol-specific phospholipase C resulted in a partial conversion of the 100 kDa peak to the 25 kDa peak. This suggests that insertion of a hydrophobic glycosylphosphatidylinositol tail into Triton X-100 micelles could give rise to large molecular size forms of the receptor on gel filtration.

Urinary excretion of albumin and transferrin in lithium maintenance treatment: daily versus alternate-day lithium dosing schedule

Urinary excretion of albumin and transferrin was determined by means of sensitive immunochemical methods in 40 manic-depressive patients prior to and following 6 months of daily or alternate-day lithium carbonate treatment. The median dose of lithium carbonate was 700 mg in the daily treatment group and 1200 mg in the alternate-day group, the corresponding median 12-h serum lithium concentration being 0.6 mmol l-1 and 0.7 mmol l-1, respectively. Urinary excretion of albumin and transferrin was significantly elevated in the lithium-treated patients as compared to a control group (Mann-Whitney). The change in urinary albumin:creatinine and transferrin:creatinine ratios between allocation and 6 months of treatment did not correlate significantly with the lithium dosing schedule (multiple linear regression), but did correlate with total lithium carbonate dose. In conclusion, the study provides no evidence of any difference in glomerular function (permeability) in the daily and alternate-day lithium dosing schedules, and lends no support to the hypothesis that alternate-day treatment diminishes the effect of lithium on renal function.

Identification of the border between fibronectin type III homologous repeats 2 and 3 of the neural cell adhesion molecule L1 as a neurite outgrowth promoting and signal transducing domain

To determine the domains of the neural cell adhesion molecule L1 involved in neurite outgrowth, we have generated monoclonal antibodies against L1 and investigated their effects on neurite outgrowth of small cerebellar neurons in culture. When the 10 antibodies were coated as substrate, only antibody 557.B6, which recognizes an epitope represented by a synthetic peptide comprising amino acids 818 to 832 at the border between the fibronectin type III homologous repeats 2 and 3, was as efficacious as L1 in promoting neurite outgrowth, increasing intracellular levels of Ca2+, and stimulating the turnover of inositol phosphates. These findings suggest that neurite outgrowth and changes in these second messengers are correlated. Such a correlation was confirmed by the ability of Ca2+ channel antagonists and pertussis toxin to inhibit neurite outgrowth on L1 and antibody 557.B6. These observations indicate for the first time a distinct site on cell surface-bound L1 as a prominent signal-transducing domain through which the recognition events appear to be funneled to trigger neurite outgrowth, increase turnover of inositol phosphates, and elevate intracellular levels of Ca2+.

Expression of the macrophage scavenger receptor in atheroma. Relationship to immune activation and the T-cell cytokine interferon-gamma

Scavenger receptors mediate internalization of modified lipoproteins and foam cell transformation of monocyte-derived cytokines. We investigated macrophage scavenger receptor (MSR) expression in monocyte-macrophages from human peripheral blood and in atherosclerotic lesions and analyzed its relationship to T lymphocytes and immunoregulatory cytokines by immunohistochemistry and polymerase chain reaction (PCR). Antibodies specific for the two MSR isoforms were generated by immunizing rabbits with isoform-specific synthetic peptides conjugated to keyhole limpet hemocyanin. In human atherosclerotic plaques, these antibodies stained macrophages and foam cells in a pattern that corresponded to the distribution of the macrophage marker CD68. CD3-positive T cells and alpha-actin-positive smooth muscle cells exhibited no reactivity to the anti-MSR antibodies. The frequency of cells stained with antibodies to MSR type I was equal to that of cells stained for type II, suggesting that most macrophages coexpress both isoforms. Reverse transcription (RT)-PCR analysis confirmed that both MSR isoforms were expressed in all plaques examined. There was, however, a tendency toward a lower immunohistochemical staining intensity for MSR type I and a decreased number of lipid-rich foam cells in T cell-rich areas. The mRNAs for interleukin-2 and interferon-gamma, two major products of activated T cells, were detected by RT-PCR in all plaques tested. This indicates that activation of T lymphocytes occurs in atherosclerotic plaques. Since interferon-gamma downregulates MSR expression, these observations suggest a potential mechanism for local regulation of MSR expression in the atherosclerotic plaque.

Oral ciprofloxacin versus intravenous cefuroxime as prophylaxis against postoperative infection in vascular surgery: a randomised double-blind, prospective multicentre study

OBJECTIVES

To test the hypothesis that oral ciprofloxacin is equally effective as intravenous cefuroxime in preventing postoperative infectious complications in patients undergoing peripheral arterial surgery involving the groins.

DESIGN

Prospective, randomised, double-blind multicentre study.

MATERIALS

580 patients undergoing arterial surgery involving the groins were randomised to ciprofloxacin (Ciproxin, Bayer) 750 mg x 2 p.o. or cefuroxime (Zinacef, Glaxo) 1.5 g x 3 i.v. given only on the day of surgery. The primary endpoint was wound/graft infection within 30 days postoperatively. Wound infection was defined as pus.

RESULTS

The wound infection rate in the ciprofloxacin group was 9.2% (27 patients) and in the cefuroxime group 9.1% (26 patients) according to intention to treat. For correct treatment the corresponding numbers were 9.5% (23 patients) and 9.7% (22 patients), respectively. There were three graft infections (0.5%). The infection rate was 7.1% (31/433) in the absence and 14.9% (22/147) in the presence of distal ulcers (p < 0.05). S. allreus was the most common bacteria isolated. Forty percent of the wound infections were localised to the groins. By multivariate analysis presence of distal ulcer was the only factor of prognostic significance.

CONCLUSIONS

The infection rate was similar in the two groups. Thus, oral administration of ciprofloxacin is an attractive, cost-effective and safe alternative to prophylaxis in vascular patients capable of taking oral medication on the day of surgery.

Control of neuronal morphology in vitro: interplay between adhesive substrate forces and molecular instruction

Among the factors which influence neuronal morphology, the degree of substrate adhesivity has been suggested to play an important role in the growth and guidance of neurites. The present study was undertaken to investigate apparently contradictory results relating substrate adhesivity to the extent of neurite outgrowth. By using substrates coated with different concentrations of polyornithine to vary adhesivity, we could show that intermediate levels of neuron-to-substrate adhesive strength favored neurite outgrowth more than substrates of high or low adhesivity. However, when neurons were plated on substrates derived from the extracellular matrix, the strength of neuron-to-substrate adhesion was important for the growth of dendrite-like minor neurites, but not for the extension of axon-like major neurites, which grew independently of adhesive forces. On substrates of the cell adhesion molecule L1, growth of both major and minor neurites was adhesion-independent. Finally, in the presence of tenascin added to the culture medium, neurite growth was inhibited irrespective of the adhesivity of the substrate and the presence of substrate-bound extracellular matrix molecules or L1. These observations suggest that intermediate forces of adhesivity favor neurite growth in general, but that purely adhesive forces can be dominated by specific molecular instructions which differentially affect growth of major and minor neurites in positive and negative ways.

Several extracellular domains of the neural cell adhesion molecule L1 are involved in homophilic interactions

The neural cell adhesion molecule L1 is a multidomain protein that plays important roles in cell adhesion, migration, and neurite outgrowth. It can interact with itself by a self-binding, i.e., homophilic adhesion mechanism (Kadmon et al.: J Cell Biol 110: 193-208, 1990a). To determine the domains of L1 involved in homophilic binding, we have generated protein fragments of L1 in a prokaryotic and a eukaryotic expression system and used these covalently coupled to fluorescent microspheres to quantify aggregation between them by cytofluorometric analysis. Protein fragments containing the first and second Ig-like domains and the third fibronectin type III homologous repeat showed avid self-binding. Ig-like domains III and IV also showed some self-binding, whereas Ig-like domains V and VI and fibronectin type III homologous repeats 1 and 2 as well as 4 and 5 were less or not active. Binding between different domains was also observed: fibronectin type III homologous repeats 4 and 5 interacted with Ig-like domains I and II, and fibronectin type III homologous repeats 3-5 interacted with all Ig-like domains. These results were confirmed by experiments testing the binding of fragment-conjugated microspheres to substrate-coated L1 or to cell surface-expressed L1 on cultured neurons. Binding of L1 to itself was interfered with by all protein fragments tested, suggesting that also less avidly binding domains of L1 contribute to homophilic binding. These observations indicate prominent functional roles of both Ig-like domains and fibronectin type III homologous repeats in homophilic binding of L1.

Folate receptor in malignant effusions of ovarian carcinoma

Binding of 3H-folate in human ovarian adenocarcinoma tissue was of a high-affinity type (K approximately 10(10) M-1) and displayed apparent positive cooperatively. A high-affinity folate receptor was also present in ascitic fluid and pleural effusion. Radioligand dissociation was slow at pH 7.4, but rapid at pH 3.5. The folate analogues methotrexate and in particular 5-formyltetrahydrofolate acted as inhibitors of 3H-folate binding in ascitic fluid. Ovarian adenocarcinoma tissue showed immunostaining with rabbit antibodies against human milk folate-binding protein. The gel filtration diagram contained two peaks of radiolabelled folate (at 25 and 100 kDa). The 25 kDa peak was predominant in ascitic fluid and pleural effusion. A single band of 70 kDa was seen on SDS-PAGE immunoblotting of tissue and malignant effusions. The concentration of folate receptor in tissue and fluid specimens could be determined by an immunochemical method (ELISA) utilizing antibodies against human milk folate-binding protein.

Surgically assisted, rapid maxillary expansion in adults. A retrospective long-term follow-up study

This study presents a technique for surgically assisted, rapid maxillary expansion performed on 20 patients and the results after orthodontic treatment. The mean age of the patients was 36.3 years and on average they had been followed-up for 3 years and 6 months. The results seemed to be reliable long-term. The definitive expansion in the first molar region was 7.1 mm +/- 2.4 and in the canine region 4.8 mm +/- 2.7. The relapse measured after the observation period, was in the corresponding regions 1.2 mm +/- 1.3 and 0.2 mm +/- 2.1. The study also seemed to support the theory that the suture, anterior to the incisive canal, never ossifies until very late in life.

[Albuminuria in persons with real hypertension, white coat hypertension and normotension]

A prospective comparison of office blood pressure, daytime ambulatory blood pressure and urinary albumin excretion was performed in 284 consecutive patients from general practice with newly diagnosed, untreated mild to moderate hypertension. Based on daytime ambulatory blood pressure 173 were classified as established hypertensives and 111 as white coat hypertensives. A sample of 127 subjects drawn from the Danish national register served as a normotensive control group. It was found that urinary albumin/creatinine ratio differed significantly between the three groups; the difference remained significant after correction for covariables. Early morning urine albumin/creatinine ratio was weakly but significantly correlated to blood pressure. Early morning urine albumin/creatinine ratio was as reproducible a measure as 24-hour albumin excretion. It is concluded that white coat hypertensive patients have less renal involvement than patients with established hypertension, but more than a normotensive control group.

Effects of spinal cord stimulation (SCS) in patients with inoperable severe lower limb ischaemia: a prospective randomised controlled study

OBJECTIVES

This study was designed to test the hypothesis that spinal cord stimulation (SCS) improves limb salvage in patients with inoperable severe leg ischaemia.

DESIGN

Prospective randomised controlled study with 18 months follow-up.

SETTING

Vascular surgical units in two university hospitals.

MATERIALS

Atherosclerotic (n = 41) and diabetic (n = 10) patients having chronic leg ischaemia with rest pain and/or ischaemic ulcerations due to technically inoperable arterial occlusions.

CHIEF OUTCOME MEASURES

Limb salvage and amount of tissue loss within 18 months, pain relief.

MAIN RESULTS

Twenty-five patients were randomized to SCS and 26 to analgesic (control) treatment. Macrocirculatory parameters were not different in the two groups during follow-up. Long-term pain relief was observed only in the SCS group. At 18 months, limb salvage rates in the SCS and control groups were 62% and 45% (N.S.). Tissue loss was less (p = 0.05) in the SCS group. A subgroup analysis of patients without arterial hypertension showed a significantly lower amputation rate in the SCS vs the control group.

CONCLUSIONS

SCS provided long-term pain relief but limb salvage at 18 months was not significantly improved by SCS in this rather small study. The results suggest that SCS may reduce amputation levels in patients with severe inoperable leg ischaemia and be most effective in patients without arterial hypertension.

When is urgent revascularization unnecessary for acute lower limb ischaemia?

OBJECTIVES

To predict the risk of gangrene by the use of simple clinical parameters available on admission.

DESIGN

Retrospective comparison using logistic regression and chi2 analyses of prospectively registered data from two patients series.

METHODS

One group of patients with acute lower limb ischaemia, (n = 61) was managed by selective initial non-operative treatment (NO) in a university hospital. The other group (n = 173) contained patients managed by early revascularisation in a multicentre (MC) study from 10 university, county and district hospitals. Gangrene and death within one month were recorded.

RESULTS

57% of patients in the NO group were initially managed by intravenous heparin followed by surgery when necessary. Impaired motor function and skin cyanosis in the ischaemic limb predicted gangrene. Patients without this combination were low risk (LR) patients and constituted 62% (NO) and 67% (MC). Non-operatively managed LR patients did not develop gangrene, whereas 14% of those undergoing early revascularisation in the two series did (p < 0.05).

CONCLUSIONS

The results suggest that patients without motor disturbance and cyanosis are at low risk of gangrene and may benefit from initial non-operative treatment, irrespective of the presumed aetiology.

T lymphocytes from human atherosclerotic plaques recognize oxidized low density lipoprotein

Atherosclerosis, an underlying cause of myocardial infarction, stroke, and other cardiovascular diseases, consists of focal plaques characterized by cholesterol deposition, fibrosis, and inflammation. The presence of activated T lymphocytes and macrophages and high expression of HLA class II molecules are indicative of a local immunologic activation in the atherosclerotic plaque, but the antigen(s) involved has not yet been identified. We established T-cell clones from human atherosclerotic plaques using polyclonal mitogens as stimuli and exposed the clones to potential antigens in the presence of autologous monocytes as antigen-presenting cells. Four of the 27 CD4+ clones responded to oxidized low density lipoprotein (oxLDL) by proliferation and cytokine secretion; this response was dependent on autologous antigen-presenting cells and restricted by HLA-DR. All clones that responded to oxLDL secreted interferon gamma upon activation, but only one produced interleukin 4, suggesting that the response to oxLDL results in immune activation and inflammation but may not be a strong stimulus to antibody production. No significant response to oxLDL could be detected in CD4+ T-cell clones derived from the peripheral blood of the same individuals. Together, the present data suggest that the inflammatory infiltrate in the atherosclerotic plaque is involved in a T-cell-dependent, autoimmune response to oxLDL.

[Augmentation ileo-cystoplasty in women with disabling urge incontinence]

The results after "clam"-augmentation cystoplasty are assessed in 11 consecutively operated women aged 35-78. All were suffering from severe urgency. Eight were urge-incontinent and six of these stress-incontinent as well. Nine patients had been operated before with a total of 14 operations. Bladder distension and parasympatholytic medication had been tried in two and seven instances respectively. One patient died of a pulmonary embolism three weeks postoperatively. Follow-up ranged from 12-52 months, mean 29 months. Eight (80% (44-97)%) of the remaining 10 patients were cured with respect to urgency. One patient was improved, and one unchanged. Three (60% (15-95)%) out of five previously stress-incontinent patients were dry, one was improved and one unchanged in spite of a subsequent stamey urethrosuspension. Eight patients (80% (44-97)%) had spontaneous micturition, one used self-catheterisation once daily and one patient was retained on an indwelling catheter. It is concluded that augmentation cystoplasty is a procedure of considerable value in patients with disabling non-neurogenic urgency, where conservative therapy and previous surgery has failed.

Patients with low stump pressure and possible pressure fall in the middle cerebral artery during carotid surgery may be identified preoperatively by transcranial Doppler

Although it has now been established that surgery is the best way to treat patients with symptomatic tight carotid stenosis, the fact remains that perioperative risks are not negligible. Patients with significant contralateral stenosis and/or no collateral flow capacity through the anterior communicating artery are likely to be at higher risk during surgery. We examined a series of 52 patients pre- and postoperatively with transcranial Doppler (TCD) and compared the results to perioperative stump pressures. Our intention was to find out whether the results of the TCD examination of the circle of Willis could be correlated to the perioperative stump pressures, and whether TCD gives reliable information about the collateral flow. We found relatively high stump pressures in patients with potential function of any communicating artery, and in the group with no collateral function most patients had low stump pressures. We also found that preoperative flow velocity fall in the middle cerebral artery (MCA) on compression of the ipsilateral internal carotid artery correlated with perioperative stump-pressure indices. However, we were unable to predict stump pressures in individual patients by flow velocity measurements in the MCA preoperatively.

Retinopathy in type II diabetes mellitus associated with above-normal urinary excretion of RBP

We performed a cross-sectional study on the urinary excretion profiles of albumin (a marker of glomerular dysfunction) and retinol-binding protein (a low molecular mass protein marker of renal proximal tubular dysfunction) in non-insulin dependent (Type II) diabetics, with or without retinopathy. The urinary excretion of both proteins, in particular retinol-binding protein, was significantly higher in patients with background/proliferative retinopathy compared to patients without retinopathy. The degree of retinopathy correlated to the urinary excretion of albumin (P < 0.005) and retinol-binding protein (P < 0.0001). Retinopathy occurred at a higher frequency in patients with above-normal urinary excretion of retinol-binding protein, both in the absence or presence of micro/macroalbuminuria. The frequency of retinopathy among micro/macroalbuminuric patients with a normal urinary excretion of retinol-binding protein did not differ significantly from that observed in patients with a normal urinary excretion of both proteins. We cannot explain the association between retinopathy and proximal tubular dysfunction in Type II diabetes. However, it is possible that both phenomena are related to a common pathogenetic factor.

The high-affinity folate receptor of normal and malignant human colonic mucosa

The hypothesis that folate depletion is a risk factor for development of colonic neoplasia prompted us to study the presence of a putative folate receptor in human colon mucosa. Binding of 3H-folate to normal and malignant mucosa studied by equilibrium dialysis was of high-affinity type (K = 10(10) L/mol) and displayed apparent positive cooperativity. Radioligand dissociation was slow at pH 7.4, but rapid at pH 3.5. As compared to methotrexate, 5-formyltetrahydrofolate was a potent inhibitor of binding. Gel filtration revealed a 25 kDa and a 100 kDa peak of folate-binding activity. Immunoreactivity studies were performed with rabbit antibodies against human 25 kDa milk folate-binding protein. Immunoblotting showed a single band at 65 kDa, and tissue sections exhibited immunostaining of mucosal areas. The present folate receptor with characteristics similar to those of other high-affinity folate-binding proteins may serve as a regulator of intracellular folate concentration in colon mucosa.

Arterial smooth muscle cells express nitric oxide synthase in response to endothelial injury

Endothelial cells regulate vascular tone by secreting paracrine mediators that control the contractility of arterial smooth muscle cells. Nitric oxide (NO) is an important vasodilating agent that is generated from L-arginine by the enzyme nitric oxide synthase (NOS), which is expressed constitutively by the endothelium. NO also inhibits platelet aggregation, contributing to the antithrombotic properties of the endothelial surface. It would therefore be expected that loss of the endothelium during arterial injury would lead to vasospasm and thrombosis but instead, the neointima formed after injury has a nonthrombogenic surface and a maintained vascular patency. We report here that arterial smooth muscle cells in the neointima formed after a deendothelializing balloon injury to the rat carotid artery express the cytokine-inducible isoform of NOS. Expression was detectable by reverse transcription-polymerase chain reaction from day 1-14 after injury and in situ hybridization showed expression of NOS mRNA by neointimal smooth muscle cells, particularly at the surface of the lesion. This was associated with systemically detectable NO production as revealed by electron paramagnetic resonance spectroscopic analysis of nitrosylated red cell hemoglobin. Local NO production by intimal smooth muscle cells after endothelial injury could represent an important mechanism for the maintenance of arterial patency and nonthrombogenicity in the injured artery.

Microalbuminuria in 411 untreated individuals with established hypertension, white coat hypertension, and normotension

We compared urinary albumin excretion in normotensive subjects and patients with white coat and established hypertension. The study involved prospective comparison of office blood pressure, daytime ambulatory blood pressure, and urinary albumin excretion in consecutive patients (n = 284) who were selected from general practice with newly diagnosed mild to moderate hypertension before the institution of pharmacologic antihypertensive therapy. All patients had a diastolic office blood pressure above 90 mm Hg; 173 had a consistently elevated diastolic blood pressure (established hypertension), and 111 had an average daytime ambulatory blood pressure below 90 mm Hg (white coat hypertension). A sample of 127 subjects drawn from the Danish national register served as a normotensive control group. The main outcome measure was the ratio of early morning urinary albumin to creatinine. This ratio differed significantly among the three groups, being (on a molar basis) 21 +/- 69 x 10(-6) in the normotensive subjects, 22 +/- 39 x 10(-6) in the white coat hypertensive patients, and 51 +/- 177 x 10(-6) in patients with established hypertension. The difference remained significant after correction for covariables. The ratio of early morning urinary albumin to creatinine was weakly but significantly correlated to blood pressure, was more pronounced for ambulatory than for office measurements, was more pronounced for systolic than for diastolic pressure, and was more pronounced for hypertensive than for normotensive individuals. The ratio was as reproducible a measure as 24-hour albumin excretion. We conclude that white coat hypertensive patients have less renal involvement than patients with established hypertension but more than a normotensive control group.

Epidural anaesthesia prolonged into the postoperative period prevents stress response and platelet hyperaggregability after peripheral vascular surgery

The occlusion rate of peripheral vascular grafts depends on technical as well as endogenous factors. Platelets play an integral part in graft failure and it has been suggested that anaesthesia may influence platelet function. In order to evaluate the influence of anaesthesia on stress response and platelet function in peripheral vascular surgery, patients (n = 18) were allocated to either general anaesthesia (GA; n = 9) followed by alleviation of postoperative pain with intramuscular analgesics or to lumbar epidural anaesthesia (EPI; n = 9) which was continued for 24 hours postoperatively. Before, during, as well as after vascular surgery of the lower extremity plasma levels of cortisol, glucose, serotonin (p-5HT), and urinary 5-hydroxyindole-3-acetic acid (5-HIAA) were analysed and platelet aggregability was determined. In the GA group surgery was accompanied by a significant stress response while in the EPI group this stress response was almost completely abolished. Platelet aggregability was reduced intraoperatively in both groups but in the postoperative period there was a marked hyperaggregability only in the GA group. P-5HT was increased preoperatively in both groups but was not affected by surgery. It is concluded that epidural anaesthesia, due to its effects on platelet aggregability, may be advantageous for peripheral vascular surgery.

Folate receptor of human mammary adenocarcinoma

Binding of 3H-folate to human mammary tumor homogenate was of a high-affinity type (K = 10(10) M-1) and displayed apparent positive cooperativity. Radioligand dissociation was slow at pH 7.4, but rapid at pH 3.5. As compared to methotrexate, 5-formyltetrahydrofolate acted as a strong inhibitor of radioligand binding. Gel chromatography of radioligand-labeled homogenate of tumor tissue revealed three peaks: a small > or = 110 kDa peak and two major peaks of folate-binding activity (M(r) approximately 25 kDa and M(r) approximately 100 kDa). Mammary tumor tissue showed immunostaining with rabbit antibodies against human milk folate binder. A parallel elevation in the concentrations of folate-binding protein and triglyceride in tumor tissue as compared to normal tissue adjacent to the tumor was compatible with the localization of folate-binding protein in the triglyceride-rich fraction of mammary gland homogenate.

Folate deficiency in cerebrospinal fluid associated with a defect in folate binding protein in the central nervous system

An adult male patient of Dutch ancestry has a slowly progressive neurological disease characterised by a cerebellar syndrome, distal spinal muscular atrophy, pyramidal tract dysfunction, and perceptive hearing loss. A severe folate deficiency state was found in CSF in combination with a normal serum and red cell folate state. Two unknown abnormal metabolites were present in CSF. The concentration of immunoreactive folate binding protein in CSF was unusually low, whereas the concentration of the protein measured with radioligand (3H-folate) binding was unusually high. The transfer of folate over the choroid plexus seems to be disturbed, potentially reflecting a defect in the choroid plexus folate binder.

Several extracellular domains of the neural cell adhesion molecule L1 are involved in neurite outgrowth and cell body adhesion

The neural cell adhesion molecule L1 is a multidomain protein that plays important roles in cell adhesion, migration, and neurite outgrowth. To analyze structure-function relationships of L1 in neurite outgrowth and cell body adhesion, we have expressed and purified a set of different fragments of the extracellular part of this glycoprotein in CHO cells and in Escherichia coli. When neurite outgrowth from small cerebellar neurons was measured on substrate-coated L1 or L1 fragments, neurite outgrowth was promoted by the immunoglobulin-like domains I-II, III-IV, and V-VI, and by the fibronectin type III homologous repeats 1-2, while the fibronectin type III homologous repeats 3-5 were ineffective. In contrast, cell bodies of small cerebellar neurons adhered mostly to the immunoglobulin-like domains I-II and V-VI, and to the fibronectin type III homologous repeats 3-5, but less to the immunoglobulin-like domains III-IV and fibronectin type III homologous repeats 1-2. In both assays, the neuronal cell surface receptor for all active protein fragments was identified as L1. No significant differences in functional activities were found between fragments with and without carbohydrate structures. These findings indicate that L1 uses several domains for homophilic interactions overlapping for the two functions analyzed here, but also showing some regional specialization. Furthermore, we show that a homophilic molecule uses several domains in one function, with neurite outgrowth requiring more domains than adhesion for maximal activity.