Comparison between Thermography and Fluorescein Test in the Detection of Incompetent Perforating Veins

Incompetent perforating veins of the legs were located by dynamic thermography at 69 sites and by the fluorescein test at 31. All the sites were explored by multiple local incisions. Incompetence of the veins was determined by demonstrating retrograde blood flow through these veins when severed. Explorations of these sites showed that thermography detected 94% and gave false-positive results in 6%, while the fluorescein test detected 16% and contributed 84% false-positive results. These findings show a highly significant difference (P <0·0005) in favour of the thermographic technique. Detection of 16% of incompetent perforating veins by the fluorescein test is statistically insignificant. This inaccuracy is thought to be due to inadequate dermal penetration of the ultraviolet rays. A positive fluorescein test probably indicates the presence of incompetent perforating veins but has little anatomical relationship to their actual site.     

Oviposition preference of cotton leafhopper in relation to leaf-vein morphology

Abstract:  The oviposition preference of the cotton leafhopper, Amrasca biguttula biguttula (Ishida) was investigated in relation to leaf-vein characteristics of 12 plant species, namely okra, cotton, castor, pigeonpea, cowpea, cluster bean, green gram, egg plant, sesame, country mallow, portia tree and shoe flower. Observations on the oviposition of the leafhopper under no-choice conditions were recorded on three occasions during the peak period of leafhopper incidence in the field. On all three occasions the leafhopper rejected green gram, shoe flower and portia tree for egg-laying, thereby indicating non-acceptance of these plants for oviposition. For the remaining plants, the number of eggs per leaf differed significantly. Okra received the maximum number of eggs. The lateral veins of castor, cotton, cowpea, egg plant and country mallow leaves received more eggs in comparison with the main vein and subveins whereas in okra the subveins received the highest number of eggs followed by lateral and main veins. The leaves of cluster bean, pigeonpea and sesame were devoid of subveins. In cluster bean and sesame the lateral veins received more eggs than the main vein but in pigeonpea the main vein received more eggs than the lateral veins. Correlations of trichome density and length with the number of eggs laid in different veins were non-significant. All types of veins in okra leaves were thicker than the rest of the test plants, which might have stimulated more egg laying in okra. The thickness of each category of vein, namely main vein ( r =0.60), lateral veins ( r =0.65) and subveins ( r =0.56) was found to be positively correlated with the number of eggs laid. The length of the main and lateral veins were also found to be positively and significantly related to the number of eggs laid. It can be concluded from the present investigations that leaf-vein thickness and length are crucial factors in influencing the oviposition behaviour of the cotton leafhopper.     

Sequelae of an 125I-Fibrinogen Detected Thrombus

Forty-four patients who had a deep vein thrombosis detected with the fibrinogen uptake test were followed up three to four years later. The mild aching pains and ankle swelling that were present at the time of the thrombosis persisted or got worse in many, but there was no increase in the incidence of varicose veins. The minor self-limiting thrombosis detected with the fibrinogen uptake test should not be considered innocuous, for it can cause long-lasting symptoms.     

Finite Element Modeling of a Beetle Wing

Numerical simulation is a very important method for understanding the behaviors of insect flight. In this study, a method of building a finite element model is proposed on the basis of a real beetle wing, which is 50 mm long in the spanwise direction and 20 mm long in the chordwise direction. We scanned a real beetle wing using a scanner to get the 2D image. The scanned 2D image was used to produce CAD data of the outer lines of the membranes and veins. Then the lines were used to build the finite element model. The model was divided into 48 regions so that the variation in the thickness of the membranes and veins could be taken into account. The effect of the cross section of the veins on the exactness of the finite element model was investigated. The finite element model was used to simulate the bending test of a real beetle wing, and the analysis results are in agreement with the experimental results.     

Mastalgia: psychoneurosis or organic disease?

To test the traditional surgical view that pain in the breast is largely an expression of psychoneurosis, the Middelesex Hospital Questionnaire was given to 317 women with mastalgia and 170 controls with varicose veins. Their scores were compared with those of 173 women psychiatric outpatients tested by the designers of the questionnaire. The results were broadly similar in the mastalgia and varicose veins groups, and where there were significant differences women with varicose veins had a higher psychoneurotic score in each case. Within the mastalgia group no difference in scores was observed between patients with cyclical mastalgia and those with mastalgia due to periductal mastitis. Both groups of surgical outpatients had significantly lower scores in major traits than the psychiatric group, except for a small group of patients with breast pain who persistently failed to respond to treatment. Patients with mastalgia are therefore no more "neurotic" than those with varicose veins, and differ greatly from patients with recognized psychoneurosis. Most patients have a physiological or pathological basis for their breast pain, and they deserve an appropriate diagnostic and therapeutic approach.     

Venous haemodynamics response to hypercapnia

The authors' aim was to evaluate the response of the intracranial venous system to application of functional tests. In 46 healthy volunteers, the basal veins were examined using venous transcranial color-coded duplex sonography. We evaluated angle-corrected venous peak-systolic flow velocities (V(vb)) in response to hypercapnia (I group: 29 subjects) and the orthostatic test (II group: 17 subjects). We have found that hypercapnia inducesa significant increase of the flow velocities in the basal veins, on average 60 +/- 22.7% (p < 0.00001). The reaction prevents venous hyperaemia, i. e., significant increase of the cerebral blood flow volume and the drainage of the brain. In contrast to hypercapnia, the orthostatic test led to decrease in the flow velocities in the basal veins. The percentage of velocity decrease ranged from 16to 32% (p < 0.001). Posturally induced reduction of the venous flow volume prevents excessive drainage from the brain. Thus, we have shown that both tests can be used for evaluation of reactivity of the intracranial venous system and they can complement each other.     

Temperature-Related Divergence in Experimental Populations of DROSOPHILA MELANOGASTER. I. Genetic and Developmental Basis of Wing Size and Shape Variation

The effects of environmental temperature on wing size and shape of Drosophila melanogaster were analyzed in populations derived from an Oregon laboratory strain kept at three temperatures (18°, 25°, 28°) for 4 yr. Temperature-directed selection was identified for both wing size and shape. The length of the four longitudinal veins, used as a test for wing size variations in the different populations, appears to be affected by both genetic and maternal influences. Vein expression appears to be dependent upon developmental pattern of the wing: veins belonging to the same compartment are coordinated in their expression and relative position, whereas veins belonging to different compartments are not. Both wing and cell areas show genetic divergence, particularly in the posterior compartment. Cell number seems to compensate for cell size variations. Such compensation is carried out both at the level of single organisms and at the level of population as a whole. The two compartments behave as individual units of selection.     

Suberized bundle sheaths in grasses (Poaceae) of different photosynthetic types. II. Apoplastic permeability

Summary The relative hydraulic conductivities of major and minor longitudinal veins, and the apoplastic permeability of the bundle sheaths surrounding all longitudinal and transverse veins were investigated in representatives of the C₃, C₄/NAD-ME, C₄/NAD-ME/PCK intermediate, C₄/PCK and C₄/NADP-ME photosynthetic types. Using the Hagen-Poiseuille equation and measurements of tracheary element diameters, the number of elements in each vein type and the numbers of each vein type, we calculated that 87–99% of the water flow in a longitudinal direction would be expected to occur in the major veins. The permeability of the mestome sheaths and parenchymatous bundle sheaths surrounding the veins was tested using the negatively-charged, fluorescent dye, trisodium 3-hydroxy-5,8,10-pyrenetrisulfonate (PTS). This dye proved nontoxic to plant tissue at a concentration of 0.5%, according to a deplasmolysis test with onion epidermal strips. The PTS concentration achieved in the tested grass leaves was about 0.035%, well below the toxic limit. When a solution of PTS was fed to the leaves by means of a basal cut, the dye moved into the veins of all orders. From there, it moved outward into the surrounding tissues, indicating that the sheaths surrounding the veins of all orders in all species tested were permeable. Therefore, contrary to previous predictions based on structural observations and some tracer studies, bundle sheaths with suberized cell walls do not function as endodermal layers.     

Fluid balance versus blood flow autoregulation in the elevated human limb: the role of venous collapse

This study evaluated the postural vascular adjustment in the human forearm which may be responsible for the recent observation that transcapillary fluid balance is maintained above the level of the heart while blood flow decreases in a linear fashion. In this study further evidence was provided that a posturally graded profile of collapsed veins holds for both an overall increase of resistance with height and compensation for hydrostatic effects on capillary pressure. This was achieved by manipulating peripheral venous profile/volume: a proximal outlet resistance (upper arm cuff) was used for re-opening of collapsed distal veins. In test (a), 12 healthy subjects underwent recordings of fluid reabsorption rate and blood flow in a 20-cm segment of their forearm horizontally placed at 36 cm above heart level (third intercostal space). Applying upper arm cuff pressures randomly between 0 and 25 mmHg (0–3.33 kPa) for 15 min led to maxima of blood flow and reabsorption rates at inflations of 5 or 10 mmHg (0.67 or 1.33 kPa). This was attributed to minima in postcapillary resistance facilitating flow and reducing capillary pressure. In test (b) the flow-maximizing outlet resistance found was studied for its effect in different forearm positions (–18, 0, 18, 36, 54 cm relative to heart level). Blood flow then showed a shift of its maximum from heart level to 36 cm above heart level, while the reabsorption rate increased above 18-cm height - in contrast to previous findings with a free circulation. It was therefore concluded that the venous profile in the forearm adjusts postcapillary resistance in such a way that local dehydration is confined at the cost of blood supply. Thicker and less collapsable veins may ensure better flow autoregulation during impaired fluid balance — as seen in the legs.     

The elastic fibre system in the veins of the human lower oesophagus

The elastic, elaunin and oxytalan fibres in the tunica mucosa and tela submucosa of veins of the human lower oesophagus were studied in 30 necropsy and biopsy specimens using appropriate histological and ultrastructural methodologies. Elaunin fibres predominate in the veins endowed with muscle cells. Scattered oxytalan and elastic fibres were also observed, the latter being more numerous at the vein periphery. No noteworthy fibre arrangement was encountered in veins lacking muscle cells. Those fibres disposed around the veins were considered to belong to the connective tissue of the tunica mucosa and tela submucosa in which they are embedded. The veins of the lower oesophagus seem to be of low elasticity, which may be related to a blockage mechanism described for the gastro-oesophageal blood stream in cases of portal hypertension.     

Cryopreservation of isolated blood vessels

Canine saphenous veins were immersed in fetal calf serum (FCS) containing various cryoprotective agents, slowly frozen and stored for several weeks at subzero temperatures. Pharmacological investigations of frozen/thawed tissues revealed considerable attenuation of the contractile force of frozen stored veins as compared to unfrozen veins. The best recovery after thawing of frozen stored canine veins was obtained on tissues which had been frozen slowly to -70 degrees C and stored in liquid nitrogen while being immersed in FCS containing 1.8 mol/l dimethyl sulfoxide (DMSO). Though the maximum response to noradranline of helical strips prepared from these veins was diminished to about 60% the evidence suggests that there may be a very good preservation of the main biochemical properties, such as monoamine oxidase activity, endogenous prostaglandin synthesis and neuronal uptake mechanism in veins stored under these conditions. The same method of cryopreservation was applied to store samples of human veins. Comparison of the pD2 values for various agonists and of the blocking activities of various antagonists of both 5-HT receptors and alpha-adrenoceptors yielded an excellent correlation between the parameters determined on frozen/thawed and unfrozen human veins. It is concluded that freezing isolated blood vessels may be considered an effective means of preserving and storing vascular tissues for pharmacological investigations.     

Microscopic Observations of the Lotus Leaf for Explaining the Outstanding Mechanical Properties

The leaf of lotus (Nelumbo nucifera) exhibits exceptional ability to maintain the opening status even under adverse weather conditions,but the mechanism behind this phenomenon is less investigated.In this paper,lotus leaves were investigated using environmental scanning electron microscopy in order to illustrate this mechanism.The macro-observations show that the primary veins are oriented symmetrically from leaf center and then develop into fractal distribution,with net-shaped arrangement of the side veins.Further micro-observations show that all the veins are composed of honeycomb micro-tubes viewed from cross section,the inner of micro-tubes are patterned with extended closed-hexagons from vertical section.Different positions of leaf possess diverse mechanical properties by size variation of diameter and inner hexagons of veins,which is theoretically analyzed by building a regular honeycomb model.Specifically,the central area of lotus tends to be stiffer while its margin be softer.These special distribution and composition of the veins mainly account for the distinct behavior of lotus.     

Developing the methodology of examining the lower limb veins in cosmonauts for the space medicine practice

The article focuses on development of a methodology for evaluating the function of lower limb veins of cosmonauts in microgravity. The whys and wherefores of the choice of occlusive plethysmography equipment and procedure are explained. Much place is given to arguments for the body and limb positioning during venous plethysmography before and after space fight. To minimize the gravity effect on venous blood flow, the body should be in the level position, with the shin aligned with the hydrodynamically indifferent point. Determining the type of occlusion test, occlusion adjustments, venous parameters of interest, and data processing procedure constitute the methodology.     

Spare alpha adrenoceptors in the peripheral circulation: excitation-contraction coupling

Postsynaptic alpha adrenoceptors in arteries and veins represent a mixed population of alpha 1 and alpha 2 adrenoceptors, with both subtypes mediating vasoconstriction. In the peripheral arterial circulation, postsynaptic vascular alpha 1 adrenoceptors are found in the adrenergic neuroeffector junction, whereas postsynaptic vascular alpha 2 adrenoceptors are located extrajunctionally. In the venous circulation, it appears that alpha 2 adrenoceptors may be predominantly junctional, whereas alpha 1 adrenoceptors may be predominantly extrajunctional. In general, alpha 1 adrenoceptors play a more important functional role in arteries than in veins, with the converse being true for postsynaptic vascular alpha 2 adrenoceptors. The relationship between alpha-adrenoceptor occupancy and vasoconstrictor response is more favorable for postsynaptic vascular alpha 1 adrenoceptors than for alpha 2 adrenoceptors in both arteries and veins, and there is evidence for a receptor reserve in alpha 1 adrenoceptors in both the arterial and venous circulation. No reserve in postsynaptic vascular alpha 2 adrenoceptors is seen in the arterial circulation, but in isolated venous preparations, a reserve in alpha 2 adrenoceptors has been observed. It has been suggested that spare alpha 2 adrenoceptors found in veins, but not arteries, may be responsible, at least in part, for the exaggerated alpha 2-adrenoceptor-mediated response of veins relative to arteries.     

Mammary Blood Flow and Venous Drainage in Cows

The mammary blood flow and the udder drainage in vivo evaluated using the antipyrine absorption method has been compared with the anatomical findings in the udder after slaughtering of the experimental cows (Table 1). Because of the orientation of the valves in the perineal veins and blood samples taken in vivo it must be assumed that the perineal veins lead blood toward the veins at the udder base. It is concluded that the drainage of the udder in standing cows will primarily be through the milk veins, eventually there will be a flow of non-mammary venous blood down the external pudic veins at the udder base, as in the case of the perineal veins.     

2 types of dynamics of filling of veins in the extremities during obstruction of venous outflow

The method of venous occlusion plethysmography improved by introduction of differential and logarithmic-computing signal amplifiers was used to study the time course of blood inflow to the limbs in 35 healthy individuals and 115 patients with diseases of lower limb veins. Two types of the time course of the vein blood content were defined. With type I the volume velocity (VV) of blood supply to the segment under study decreases, whereas with type II the VV first decreases and then remains unchanged for a long time. Type I occurs in 76% of healthy individuals, type II in 74% of patients. With type II the increment of the vein capacity is significantly reduced in both healthy individuals and in patients with varicose veins. Moreover, in healthy individuals, the VV, the time of constant venous volume attainment, and the rate of blood outflow from veins (after occlusion removal) significantly differ as well in types I and II. Both types of the blood content remain unchanged while both applying the functional tests and during examinations at varying times. It is assumed that type II blood content is determined by greater rigidity of the venous vessels.     

Angioarchitecture of the esophagogastric veins in portal hypertension

Based on our previous studies on the human normal venous angioarchitecture of the esophagogastric transition segment, we performed a similar analysis in 25 postmortem specimens obtained from subjects with a diagnosis of portal hypertension. The specimens were injected with India ink or barium sulfate and sectioned for histological examination. A 'weak' zone (point of lesser resistance) was described as being the most probable site of origin for the development of varicosities in the complex venous system of the esophagogastric junction. Such a system can be considered to be a physiological hemodynamic venous blockade mechanism interposed between the portal system and the systemic veins. The 'weak' zone is made up by the scarce submucous veins (shunt veins), by the submucous confluent and final confluent trunks, and by the true perforating veins of the tunica muscularis which compose a venous unity located about 3-5.5 cm above the Z (epithelioglandular) line.     

Selecting a treatment for primary varicose veins.

The treatment of varicose veins includes injection/compression sclerotherapy and surgical stripping or ligation or both. Surgery appears to be favoured when the saphenous system is involved or when the patient is 35 to 64 years old or presents with ankle edema or flare. On the other hand, sclerotherapy has been found to be more effective in patients with dilated superficial veins or incompetent perforating veins in the lower legs and to be more acceptable and less expensive than surgical treatment.     

Psychogenic and neurogenic effects on the intact forearm vein of man.

By means of an elegant venous preparation the behavior of intact veins of man can be studied decisively. The superficial veins of man are extremely sensitive to the environment and the autonomic and central nervous systems. This report illustrates the response of an isolated venous segment of the forearm to various psychogenic and neurogenic stimuli, with change in tone of the smooth muscle of the venous segment being reflected by change in segmental venous pressure. It is shown that the superficial forearm veins can be conditioned and that they are extremely dynamic and certainly not passive conduits for returning blood to the heart.