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.