Laboratory response to intranasal desmopressin in women with menorrhagia and platelet dysfunction.

Intranasal desmopressin (IN-DDAVP) is used for home treatment of menorrhagia in women with inherited bleeding disorders. The effect of IN-DDAVP on laboratory haemostatic parameters in women with menorrhagia related to platelet dysfunction is unknown. We evaluated the effects of IN-DDAVP on haemostatic parameters in women with menorrhagia and platelet dysfunction and correlated them with menstrual flow. Eleven women (aged 18-45) with menorrhagia and haemostatic abnormalities had determination of von Willebrand factor antigen (VWF:Ag), von Willebrand factor ristocetin cofactor (VWF:RCo) activity, factor VIII coagulant activity (FVIII:C), platelet aggregation and platelet adenosine tri-phosphate (ATP) release pre-IN-DDAVP and 60-min post-IN-DDAVP. Eight of eleven women underwent platelet function analyzer (PFA-100) closure time determination with collagen/adrenaline and collagen/adenosine diphosphate cartridges pretreatment and post-treatment. IN-DDAVP was administered during two consecutive menstrual cycles. Menstrual flow was assessed during each cycle using a pictorial blood assessment chart. Treatment with IN-DDAVP resulted in elevated VWF levels and shortened PFA-100 closure time with significant inverse correlation between shortening of PFA-100 closure times and increases in VWF levels. There were also significant inverse correlations between changes in menstrual flow and changes in VWF:Ag (P = 0.02), VWF:RCo (P = 0.04) and FVIII:C (P = 0.006), following treatment. In vitro platelet aggregation and platelet ATP release response did not correct and did not correlate with changes in menstrual flow. Our results demonstrate a correlation between haemostatic parameters and menstrual flow following IN-DDAVP in women with menorrhagia and platelet dysfunction.

The feasibility of a porcine model of acute coronary occlusion and reperfusion using off-pump coronary artery bypass grafting

We developed an open-chest porcine model of acute coronary occlusion and surgical reperfusion, and attempted to prevent intra-operative ischaemic ventricular fibrillation (VF) by a Retrograde Intracoronary Glyceryl trinitrate (RIG) infusion into the occluded vessel. Five Yorkshire pigs (weight 50 +/- 1.1 kg), randomized into 3 groups, underwent median sternotomy under general anaesthesia. One pig (Group 1, control) underwent sternotomy and pericardiotomy only. Four pigs underwent acute left anterior descending (LAD) coronary occlusion. Two pigs were not reperfused (Group 2). Two pigs underwent surgical reperfusion (Group 3) via left internal mammary artery (LIMA) grafting to the LAD using the Off-Pump Coronary Artery Bypass (OPCAB) technique. Ischaemic injury was assessed using 7-lead electrocardiography (ECG) and transthoracic/epimyocardial echocardiography (ECHO). Group 1: transient intraoperative hypotension and VF occurred. Successful resuscitation and 10-week survival (until sacrifice) with normal left ventricular (LV) function was achieved. Group 2: there were ECG and ECHO evidence of acute LV ischaemic dysfunction in both pigs. The surviving pig had persistent anterior hypokinesis at 8 1/2 months. The other died intra-operatively following progressive ischaemic LV dysfunction despite resuscitative attempts. Group 3: the surviving pig had normal LV function at 8 months. Initial anterior LV akinesis normalized within 7 days. The other developed post-occlusion haemodynamic instability and died intra-operatively despite reperfusion. In this porcine model, acute LAD artery occlusion modified by the novel RIG infusion technique, followed by surgical reperfusion (OPCAB) is feasible. This model would facilitate further development of OPCAB surgical expertise and understanding of the pathophysiology of ischaemia-reperfusion injury.

The feasibility of a porcine model of acute coronary occlusion and reperfusion using off-pump coronary artery bypass grafting.

We developed an open-chest porcine model of acute coronary occlusion and surgical reperfusion, and attempted to prevent intra-operative ischaemic ventricular fibrillation (VF) by a Retrograde Intracoronary Glyceryl trinitrate (RIG) infusion into the occluded vessel. Five Yorkshire pigs (weight 50 +/- 1.1 kg), randomized into 3 groups, underwent median sternotomy under general anaesthesia. One pig (Group 1, control) underwent sternotomy and pericardiotomy only. Four pigs underwent acute left anterior descending (LAD) coronary occlusion. Two pigs were not reperfused (Group 2). Two pigs underwent surgical reperfusion (Group 3) via left internal mammary artery (LIMA) grafting to the LAD using the Off-Pump Coronary Artery Bypass (OPCAB) technique. Ischaemic injury was assessed using 7-lead electrocardiography (ECG) and transthoracic/epimyocardial echocardiography (ECHO). Group 1: transient intraoperative hypotension and VF occurred. Successful resuscitation and 10-week survival (until sacrifice) with normal left ventricular (LV) function was achieved. Group 2: there were ECG and ECHO evidence of acute LV ischaemic dysfunction in both pigs. The surviving pig had persistent anterior hypokinesis at 8 1/2 months. The other died intra-operatively following progressive ischaemic LV dysfunction despite resuscitative attempts. Group 3: the surviving pig had normal LV function at 8 months. Initial anterior LV akinesis normalized within 7 days. The other developed post-occlusion haemodynamic instability and died intra-operatively despite reperfusion. In this porcine model, acute LAD artery occlusion modified by the novel RIG infusion technique, followed by surgical reperfusion (OPCAB) is feasible. This model would facilitate further development of OPCAB surgical expertise and understanding of the pathophysiology of ischaemia-reperfusion injury.

Estrogen and progesterone receptors in normal and varicose saphenous veins.

The presence of estrogen and progesterone receptors was investigated in the walls of normal and varicose veins. Cryostat sections from the saphenous veins of 29 normal individuals, and varicose and normal vein segments of 32 patients with varicose veins, were stained with anti-estrogen or anti-progesterone receptor antibodies. Nuclear stain intensity was scored by three independent observers. Receptors to both hormones were detected in the nuclear regions of the intima and media in females and males. In the adventitia, estrogen and the progesterone receptors were found only in nuclei of the vasa vasorum. Estrogen receptor levels were lower in non-varicose segments of varicose veins compared with normal veins. In varicose segments, estrogen receptors were more abundant than in the non-varicose parts of the same vein, especially in females. Similarly, progesterone receptor levels in the non-varicose portions were higher in females. These gender differences may be related to hormonal action. However, these differences may also be age related. These findings may be related to the involvement of sex-hormones in varicosis, by mechanisms as yet unknown.

Collagen subtype pattern in normal and varicose saphenous veins in humans.

Our present study was to determine the collagen subtype pattern in the greater saphenous vein of the lower limb, obtained from 21 normal (macroscopically and ultrastructurally non-varicose vein segments from non-varicose subjects) and 37 varicose subjects, and to compare affected (macroscopically and ultrastructurally varicose segments from varicose veins) vs. non-affected (macroscopically and ultrastructurally non-varicose segments from varicose veins) segments (16). After elastase pretreatment and partial pepsin digestion, types I, III & V collagens (CI, CIII, CV) were extracted selectively by differential salt precipitation and measured quantitatively in samples obtained from normal and varicose saphenous veins-either affected or unaffected segments. Significant elevations of water (p < 0.05) and collagen type I [CI] (p < 0.01) content in varicose veins (both affected and unaffected segments) as compared with normal saphenous veins were observed. The collagen type III (CIII) and collagen type V (CV) content of varicose veins were found to be slightly reduced as compared to normal veins and consequently the CI/(CIII+CV) ratio in varicose veins increased significantly (p < 0.02) as compared to normal veins. Elevation of the CI/(CIII+CV) ratio in varicose veins may cause considerable weakening of the venous wall, further supporting the "weak wall" theory of varicose vein etiology.

Characterization of transendothelial chemotaxis of T lymphocytes.

We have adapted a chemotaxis assay using human umbilical vein endothelial cell (HUVEC) monolayers on microporous membranes for studying lymphocyte transendothelial chemotaxis in vitro. Supernatants of peripheral blood mononuclear cells stimulated with phytohemagglutinin (PHA) were identified as an excellent source of lymphocyte chemoattractant activity. The activity in PHA supernatant typically caused 2-6% of peripheral blood lymphocytes (PBL) to transmigrate compared to 0.1-0.3% to media control. Checkerboard analysis demonstrated that transmigration was directional and not attributable to random locomotion. Purified T lymphocytes also underwent transendothelial chemotaxis to PHA supernatant. Using monoclonal antibodies to several human adhesion receptors, we found that the interaction between LFA-1 and ICAM-1/ICAM-2 was more important for transendothelial lymphocyte chemotaxis than the interaction between VLA-4 and VCAM-1. A monoclonal antibody to the beta 1 integrin subunit inhibited chemotaxis more than antibodies to the VLA alpha 2, alpha 3, alpha 4, or alpha 5 subunits. The transendothelial assay was used to guide purification of the lymphocyte chemoattractant activity, which we reported previously to be monocyte chemoattractant protein-1 (MCP-1) (Carr et al., Proc. Natl. Acad. Sci. USA (1994) 91, 3652). The adhesion molecules required for chemotaxis to MCP-1 were similar to those with PHA supernatant. The use of HUVEC in the assay enhances the signal-to-background ratio of chemotaxis and provides a model that is physiologically relevant to lymphocyte emigration from the bloodstream into sites of inflammation.

Monocyte chemoattractant protein 1 acts as a T-lymphocyte chemoattractant.

We have utilized a transendothelial lymphocyte chemotaxis assay to identify and purify a lymphocyte chemoattractant in supernatants of mitogen-stimulated peripheral blood mononuclear cells. Amino acid sequence analysis revealed identity with monocyte chemoattractant protein 1 (MCP-1), a chemoattractant previously thought to be specific for monocytes. Recombinant MCP-1 is chemoattractive for purified T lymphocytes and for CD3+ lymphocytes in peripheral blood lymphocyte preparations. The T-cell response to MCP-1 is dose-dependent and chemotactic, rather than chemokinetic. Phenotyping of chemoattracted T lymphocytes shows they are an activated memory subset. The response to MCP-1 by T lymphocytes can be duplicated in the absence of an endothelial monolayer and the majority of T-lymphocyte chemotactic activity in mitogen-stimulated peripheral blood mononuclear cell supernatants can be neutralized by antibody to MCP-1. Thus, MCP-1 is the major lymphocyte chemoattractant secreted by mitogen-stimulated peripheral blood mononuclear cells and is capable of acting as a potent T-lymphocyte, as well as monocyte, chemoattractant. This may help explain why monocytes and T lymphocytes of the memory subset are always found together at sites of antigen-induced inflammation.

The scanning electron microscope in the pathology of varicose veins.

We studied varices of the lower limb by scanning electron microscope (SEM) in 29 women who had undergone surgery under local anesthesia for symptomatic varicose veins. Their ages ranged between 19 and 42 years (average 30). They were all diagnosed as having incompetence of the valve at the saphenofemoral junction. The surgical procedure was high ligation of the long saphenous vein, excision of the upper portion of the vein and multiple excision of all the varices along the leg through several tiny incisions. Segments of the removed varices and the upper portion of the long saphenous vein were prepared and studied by the Jeol scanning electron microscope (Japan, model 355c). We found no changes in the intima or adventitia and no changes in any of the upper valves of the saphenous vein; however, varying degrees of thinning of the media of the venous wall were seen, which coincided with the areas of varicose dilatation between areas that retained their normal configuration. Our study therefore supports the "weak vein wall" theory concerning the etiology of varicose veins, and confirms that surgery for varicose veins of the lower limb must concentrate on removal of the varices themselves. Since these often lie outside the long saphenous vein, routine stripping is neither advisable nor effective.

Some thoughts on the aetiology of varicose veins.

The accepted view that varicose veins are primarily due to valvular incompetence is challenged and the alternative theory of weakness of the vein wall is supported by the correlation of clinical, operative and histological findings. It is shown that there appears to be a basic abnormality of the muscle cell associated with abnormal collagen infiltration. The morphological changes in the vein wall are demonstrated by light microscopy and transmission electron microscopy. It is thought that the cause of these changes are to be sought in an investigation of the enzyme systems involved in maintaining tissue equilibrium in the vein wall.

Lumbar sympathectomy.

The three points discussed in this paper are: 1. Improvement in walking distance. 2. Post-sympathectomy neuralgia. 3. Post-sympathectomy ejaculatory problems. The experience in the paper was derived from 2,450 operations of lumbar sympathectomy carried out between the years of 1947 and 1972. The claudicant patients were divided into 3 main groups. Those who were not treated by any form of surgery, those who could walk for 200 yards before claudication and those who could walk less than 100 yards before claudication, the latter two groups having been treated by lumbar sympathectomy. The results show a considerable difference in the two groups treated and compare favourably with the untreated cases.