Faint Symptoms Research Articles

The mechanism of orthostatic and haemorrhage fainting.

In order to study the adjustment of central circulation to postural changes and the mechanism of orthostatic fainting, the pressure in the brachial artery, the pulmonary artery, the right ventricle and heart rate (HR) were recorded in sixteen healthy young men, both supine and after tilting to 45 degrees and 90 degrees head up, before (normovolaemic, NV) as well as after (hypovolaemic, HV) withdrawal and reinfusion of (mostly) 950 g blood (about 15% of blood volume, BV). Two subjects fainted in supine HV, two in 90 degrees NV, four disclosed impending symptoms of fainting, and two fainted in 90 degrees HV. 'Fainters' differed from the others by smaller BV in relation to body height, higher HR in 90 degrees NV and lower arterial mean pressure in HV. In the three fainting situations, right ventricular enddiastolic pressure (PRveD) was markedly lowered to or below 0 mmHg. Arterial diastolic pressure (PaD) was not correlated with PRveD, but the pulse pressure decreased with the fall in PRveD. In 90 degrees HV, PaD fell in the six subjects who fainted or disclosed impending symptoms. Irrespective of the situation, the fainting attack involved a sudden decrease of HR and arterial pressure, concomitantly with a first unchanged then increased PRveD and/or pulmonary artery diastolic pressure. A reflex control of the filling volume/pressure of the heart is assumed to precipitate fainting by counteracting the arterial blood pressure regulation.

EVALUATION OF THE GRAVIGARD INTRAUTERINE COPPER CONTRACEPTIVE DEVICE *

The plastic intrauterine device is now being used as a carrier to hold the contraceptive agent (copper in this case) in the uterus. The action of copper as a contraceptive agent is thought to be due to an alteration in intrauterine environment thus preventing implantation and causing rapid loss or destruction of the fertilized ova. Studies show that such local use of copper appears to be safe over long-term use and no changes in cervical cytology or endometrial histology and no evidence of tumor production due to copper have been seen. Presented here is a study of 127 women using a Gravigard (Copper 7) IUD. The patients ranged from 18 to 42 years old and 33 (26%) were nulliparous. Insertion was easy in 111 (87%) there were minor problems in 10 (8%) and difficulties in 6 (4.7%). The majority of patients had no immediate postinsertion pain or problems but 11 (9%) did complain of uterine cramps or symptoms of faintness or nausea. 3 patients were lost to follow-up and the remaining 124 women were followed over a total of 1089 woman-months. 7 patients (5.5%) expelled the Gravigard 3 (2.4%) became pregnant and 10 (7.9%) had their IUDs removed for medical reasons.

G/G-Translokation im Mosaik bei einem Mädchen mit schwach ausgeprägtem Erscheinungsbild des Mongolismus

Es wird uber ein 5jahriges Madchen mit G/G-Translokation im Mosaik berichtet (9,3% Zellen mit 2 n=46,XX,G-,t(GqGq)+). Bei dem Kind fand sich eine fur Mongolismus relativ hohe Intelligenz (EQ 0,8). Die fur Mongolismus typischen Merkmale waren zwar in groserer Zahl vorhanden, aber meist nur schwach ausgepragt. Die Papillarleisten waren in der fur Mongolismus typischen Weise verandert.

Título en español.

Resumen en español.

CAROTID SINUS REFLEX HYPERSENSITIVITY

Excerpt It is not unusual to see patients who present symptoms of fainting, nausea, vomiting and convulsions without the presence on examination of any obvious pathological condition which might ex...

The Susceptibility Of Certain Potato Varieties To Leaf‐Roll And Mosaic Infection

Summary.1. A trial planned to ascertain whether any differences in susceptibility to leaf‐roll and mosaic infection existed in seven varieties—two of which had been included in a revious trial—was laid down in 1929. It consisted of four replicated plots for each disease; the varieties being randomised in the plots to secure uniform chances of infection. Sources of infection were provided by drills of diseased plants alternating with varieties under test.2. Mosaic was generally transmitted but with such faint symptoms that percentage infection could not be determined. The apparent loss of vigour was very slight, but losses ascertained by weighing the crop, against that given by normal plants, ranged from 0·8 to 24·4 per cent.3. Leaf‐roll infection was very heavy; most varieties showing from 90 to 100 per cent. infection of the plants. Tuber infection on the infected plants was also heavier than in 1924, and ranged from 77·3 to 99·9 per cent. Both haulm (or plant) infection and tuber infection thus showed a marked dependence upon seasonal factors which affect the breeding of insect vectors.4. The loss in yield due to leaf‐roll was found to be the most reliable guide to the susceptibility of a variety. This loss cannot be estimated from the degree of stunting or the number of rolled leaves on a plant, but only by weighing and grading the crop. Some evidence is presented to show that loss in yield of an infected plant is less dependent upon seasonal factors than percentage haulm or tuber infection, and that, therefore, figures showing such losses have a more general applicability to other localities and seasons. On this assumption a table of susceptibility of fifteen varieties has been constructed.5. Although the variety Field Marshal suffered little from leaf‐roll infection, heavy losses occurred when mixed leaf‐roll and mosaic viruses entered the plant. In large tubers receiving mixed infection the effect was to produce neither leaf‐roll nor mosaic symptoms, but “crinkle.” The small tubers, however, gave apparently pure leaf‐roll.6. The value to be attached to field trials of this kind, and their applicability to other conditions, is discussed in detail. Suggestions are offered for improvement in the technique for such trials.

STUDIES ON POTATO VIRUS DISEASES:VI. FURTHER EXPERIMENTS WITH THE VIRUS OF A POTATO MOSAIC UPON THE TOBACCO PLANT

Summary.Further experiments with the virus of a potato mosaic upon the tobacco plant are described. Marked increase in virulence has been shown to occur in ringspot by progressive needle inoculation through succeeding tobacco plants. Four strains of ringspot arising from four distinct mosaic potato plants (var. Arran Victory) have been so experimented with in White Burley and Virginia tobaccos. Comparison of needle and aphis (M. persicae) inoculations of healthy potato plants from a tobacco plant affected with the virulent ringspot shows that although both methods of inoculation produce an intensified mosaic in the potato plant, that produced by the needle is often fatal to the potato. Comparison of needle and aphis (M. persicae) inoculations of healthy tobacco plants from a tobacco plant affected with the virulent ringspot shows that while the needle reproduces the virulent disease, the aphis produces a mottle and dark green lines disease, apparently the same as that produced by aphis transmission from the ordinary type of ringspot. An analysis is given of a large comparative series of aphis and needle inoculations with potato mosaic and tobacco ringspot. This indicates that the aphis‐induced disease is an infectious virus of constant charaeter. The experiments also show that the aphis fails to transmit the more lethal characters of the disease. The response of different varieties of tobacco to the virulent virus was examined. Six varieties were used in the experiments: White Burley, Virginia, Kentucky, Maryland, Havana, Connecticut; Virginia was found to be the most resistant, and White Burley the most susceptible, while the other four varieties approximated to White Burley in susceptibility. Large numbers of seeds were sown which had been derived from tobacco plants affected with ringspot and its various modifications. In no case was the disease transmitted through the seed. Experiment showed that the virulent virus was present in the roots of an affected tobacco plant; and also that needle inoculation of the roots of healthy tobacco plants with the virulent virus produced the typical disease. It was found that certain individual tobacco plants, both Virginia and White Burley, seem to possess an inherent resistance to the virulent virus which attenuates it. Needle inoculation of such a plant with the virulent virus produces faint symptoms only. When juice from this plant is passed on to other tobacco plants the virus still shows weak symptoms, as compared with those produced by the same strain of virus before its passage through such a resistant plant. This seems to indicate that certain plant individuals have the power of attenuating the virus. A description is given of some preliminary attempts to produce experimentally in tobacco plants an immunity to the virulent virus. Plants were first inoculated with a suspension of “dead” virus, killed by heating, and three weeks later they were inoculated with the same strain of virus unheated. Experiments were also performed giving, first, inoculations with the virus artificially attenuated, and then inoculating with the virulent virus. Tobacco plants affected with the aphis‐produced disease were also needle‐inoculated with the virulent virus. A series of resistant individual plants which had developed only a mild disease after inoculation with the virulent virus, was inoculated a second time, with the same strain of virus in some cases and in others with a different strain. In all the above experiments the normal virulent disease developed, no immunity having been conferred. Tubers, from potato plants infected the previous year with tobacco ringspot, were grown in order to study the behaviour of the virus after a winter spent in the resting tuber. Plants were produced exhibiting all the symptoms of the intensified mosaic characteristic of infection with tobacco ringspot which were exhibited by the parent plants the year before. This seems to indicate that the change induced in the virus of a potato mosaic by passage through tobacco may be of a permanent nature.